text stringlengths 8 5.77M |
|---|
require 'rubygems'
require 'fileutils'
require 'rubygems/mirror/version'
class Gem::Mirror
autoload :Fetcher, 'rubygems/mirror/fetcher'
autoload :Pool, 'rubygems/mirror/pool'
SPECS_FILES = [ "specs.#{Gem.marshal_version}", "prerelease_specs.#{Gem.marshal_version}", "latest_specs.#{Gem.marshal_version}" ]
DEFAULT_URI = 'http://production.cf.rubygems.org/'
DEFAULT_TO = File.join(Gem.user_home, '.gem', 'mirror')
RUBY = 'ruby'
def initialize(from = DEFAULT_URI, to = DEFAULT_TO, parallelism = nil, retries = nil, skiperror = nil)
@from, @to = from, to
@fetcher = Fetcher.new :retries => retries, :skiperror => skiperror
@pool = Pool.new(parallelism || 10)
end
def from(*args)
File.join(@from, *args)
end
def to(*args)
File.join(@to, *args)
end
def update_specs
SPECS_FILES.each do |sf|
sfz = "#{sf}.gz"
specz = to(sfz)
@fetcher.fetch(from(sfz), specz)
open(to(sf), 'wb') { |f| f << Gem::Util.gunzip(File.binread(specz)) }
end
end
def gems
gems = []
SPECS_FILES.each do |sf|
update_specs unless File.exist?(to(sf))
gems += Marshal.load(File.binread(to(sf)))
end
if ENV["RUBYGEMS_MIRROR_ONLY_LATEST"].to_s.upcase != "TRUE"
gems.map! do |name, ver, plat|
# If the platform is ruby, it is not in the gem name
"#{name}-#{ver}#{"-#{plat}" unless plat == RUBY}.gem"
end
else
latest_gems = {}
gems.each do |name, ver, plat|
next if ver.prerelease?
next unless plat == RUBY
latest_gems[name] = ver
end
gems = latest_gems.map do |name, ver|
"#{name}-#{ver}.gem"
end
end
gems
end
def existing_gems
Dir.glob(to('gems', '*.gem'), File::FNM_DOTMATCH).entries.map { |f| File.basename(f) }
end
def existing_gemspecs
Dir[to("quick/Marshal.#{Gem.marshal_version}", '*.rz')].entries.map { |f| File.basename(f) }
end
def gems_to_fetch
gems - existing_gems
end
def gemspecs_to_fetch
gems.map { |g| "#{g}spec.rz" } - existing_gemspecs
end
def gems_to_delete
existing_gems - gems
end
def update_gems
gems_to_fetch.each do |g|
@pool.job do
@fetcher.fetch(from('gems', g), to('gems', g))
yield if block_given?
end
end
if ENV["RUBYGEMS_MIRROR_ONLY_LATEST"].to_s.upcase != "TRUE"
gemspecs_to_fetch.each do |g_spec|
@pool.job do
@fetcher.fetch(from("quick/Marshal.#{Gem.marshal_version}", g_spec), to("quick/Marshal.#{Gem.marshal_version}", g_spec))
yield if block_given?
end
end
end
@pool.run_til_done
end
def delete_gems
gems_to_delete.each do |g|
@pool.job do
File.delete(to('gems', g))
yield if block_given?
end
end
@pool.run_til_done
end
def update
update_specs
update_gems
cleanup_gems
end
end
|
On Thu, Oct 13, 2011 at 1:17 PM, Scott Fines wrote:
> When I look at the source for ColumnFamilyInputFormat, it appears that it does a call to client.describe_ring; when you do the equivalent call with nodetool, you get the 10.1.1.* addresses. This seems to indicate to me that I should open up the firewall and attempt to contact those IPs instead of the normal thrift IPs.
>
> That leads me to think that I need to have thrift listening on both IPs, though. Would that then be the case?
My mistake, I thought I'd committed this:
https://issues.apache.org/jira/browse/CASSANDRA-3214
Can you see if that solves your issue?
-Brandon |
A major goal of the human genome project is identification of the complete set of human genes. Single-pass, partial sequencing of cDNA clones to generate ESTs provides a rapid and cost-effective method of gene discovery. At the same time, sequence information contained within ESTs provides a key resource for gene mapping. Understanding the function of newly identified human genes requires the increased use of model organisms that can be genetically manipulated. The generation of ESTs from model organisms and comparative genome mapping of these ESTs can also be exploited for human disease gene hunting, as well as investigating the large-scale structure and organization of the genome. The rat is an important experimental model for studying the genetic basis of many human diseases and a wide array of genetically bred rat strains with disease characteristics are available. Hence, it would be beneficial to generate an EST catalog and unique gene index of The rat genome. This application proposes the following specific aims: (1) Generate a rat EST catalog (REST) by randomly sampling cDNA clones from normalized rat cDNA libraries of different tissues. (2) Construct non- normalized full-length rat cDNA libraries and employ micro array technology. |
Q:
Font size relative to the user's screen resolution?
I have a fluid website and the menu is 20% of its width. I want the font size of the menu to be measured properly so it always fits the width of the box and never wrap to the next line.
I was thinking of using "em" as a unit but it is relative to the browser's font size, so when I change resolutions the font size stays the same.
Tried also pts and percentages. Nothing works as I need it...
Give me a hint of how to proceed, please.
A:
You can use em, %, px. But in combination with media-queries See this Link to learn about media-queries. Also, CSS3 have some new values for sizing things relative to the current viewport size: vw, vh, and vmin. See link about that.
A:
@media screen and (max-width : 320px)
{
body or yourdiv element
{
font:<size>px/em/rm;
}
}
@media screen and (max-width : 1204px)
{
body or yourdiv element
{
font:<size>px/em/rm;
}
}
You can give it manually according to screen size of screen.Just have a look of different screen size and add manually the font size.
A:
New Way
There are several ways to achieve this.
CSS3 supports new dimensions that are relative to view port. But this doesn't work in android.
3.2vw = 3.2% of width of viewport
3.2vh = 3.2% of height of viewport
3.2vmin = Smaller of 3.2vw or 3.2vh
3.2vmax = Bigger of 3.2vw or 3.2vh
body
{
font-size: 3.2vw;
}
see css-tricks.com/.... and also look at caniuse.com/....
Old Way
Use media query but requires font sizes for several breakpoints
body
{
font-size: 22px;
}
h1
{
font-size:44px;
}
@media (min-width: 768px)
{
body
{
font-size: 17px;
}
h1
{
font-size:24px;
}
}
Use dimensions in % or rem. Just change the base font size everything will change. Unlike previous one you could just change the body font and not h1 everytime or let base font size to default of the device and rest all in em.
“Root Ems”(rem): The “rem” is a scalable unit. 1rem is equal to the font-size of the body/html, for instance, if the font-size of the document is 12pt, 1em is equal to 12pt. Root Ems are scalable in nature, so 2em would equal 24pt, .5em would equal 6pt, etc..
Percent (%): The percent unit is much like the “em” unit, save for a few fundamental differences. First and foremost, the current font-size is equal to 100% (i.e. 12pt = 100%). While using the percent unit, your text remains fully scalable for mobile devices and for accessibility.
see kyleschaeffer.com/....
|
Q:
Designing a parking lot
Description:
Given a parking lot containing multiple levels and each level containing multiple rows and each row in turn containing multiple spots. The questions is to determine if there are enough spots to check if a vehicle can be parked.
Which object is responsible to determine if there is enough spots, I mean its the parking lot object which is supposed to receive the first query but ultimately it should be either level or row to implement the actual algorithm, right?
Its not about a single class but system as a whole.
Requirement:
The parking lot has multiple levels. Each level has multiple rows of spots.
The parking lot can park motorcycles, cars, and buses.
The parking lot has motorcycle spots, compact spots, and large spots.
A motorcycle can park in any spot.
A car can park in either a single compact spot or a single large spot.
A bus can park in five large spots that are consecutive and within the same row. It cannot park in small spots.
The question is that the given system should be able to given answer to the queries like:
Given a car the system should be able to tell if there is a spot for car or not, if yes the answer should be something like:
There is a spot on level x row y and spot z
The issues I face while solving such problems is where to start and how to find correct objects which should represent the domain correctly.
I did try to start somewhere and below is my code:
Enum Size {
SMALL,
COMPACT,
LARGE
}
private class Spot {
private boolean empty;
private int number;
private Size size;
Spot(Size size, int number) {
this.size = size;
}
full() {
this.empty = false;
}
empty() {
this.empty = true;
}
status() {
return this.empty;
}
boolean canPark(Vehicle vehicle) {
return false;
}
}
class LargeSpot extends Spot {
boolean canPark(Vehicle vehicle) {
return
vehicle.size() == Size.LARGE ||
vehicle.size() == Size.COMPACT ||
vehicle.size() == Size.SMALL;
}
}
class CompactSpot extends Spot {
boolean canPark(Vehicle vehicle) {
return
vehicle.size() == Size.COMPACT ||
vehicle.size() == Size.SMALL;
}
}
class SmallSpot extends Spot {
boolean canPark(Vehicle vehicle) {
return vehicle.size() == Size.SMALL;
}
}
private class Row {
private ArrayList<Spot> spots;
Row(List<Spot> spots) {
this.spots = spots;
}
void spot(Spot spot) {
this.spots.add(spot);
}
List<Spot> getSpots(Vehicle vehicle) {
List<Spot> emptySpots = new ArrayList<>();
if (vehicle.size() == Size.LARGE) {
// five consecutive large spots
int length = spots.size();
for (int i = 0; i < length; i++) {
int j = 0;
for (; j < 5; j++) {
if (!spot.canPark(vehicle)) break; // break out of inner loop
}
if (j == 5) { // found five spots
for (int k = i; k < i + j; k++) {
emptySpots.add(spot);
}
i += j;
}
}
} else {
for (Spot spot : spots) {
if (spot.canPark(vehicle)) {
emptySpots.add(spot);
}
}
}
return emptySpots;
}
}
private class Level {
private final int number;
private final ArrayList<Row> rows;
Level(number, rows) {
this.number = number;
this.rows = rows;
}
}
class ParkingLot {
private List<Level> levels;
ParkingLot(List<Level> levels) {
this.levels = levels;
}
public String status(Vehicle vehicle) {
List<Spot> emptySpots = new ArrayList<>();
for (Level level : levels) {
for (Row : level.rows()) {
if (row.canPark(vehicle)) {
emptySpots.addAll(row.getSpots(vehicle));
}
}
}
return emptySpots;
}
}
public class Main {
private final List<Level> floors = new ArrayList<>();
floors.add(
new Level(
0,
new Row[4]{new SmallSpotSpot(), new CarSpot(), new CarSpot()}));
floors.add(
new Level(
1,
new Row[4]{
new LargeSpot(), new LargeSpot(), new LargeSpot(), new LargeSpot()}));
private final Lot lot = new ParkingLot(floors);
private final Car car = new Car(Size.Compact);
System.out.println(lot.status(car));
}
The code definitely broken at many places but the readers can get the faint idea what I am trying to achieve. Also, it can be seen parking Large vehicle is one of the pain points in designing a good solution.
A:
You're question is about what to model.
On the one hand, there is an obvious structure to the real-world situation: a lot, having levels, having rows, and ultimately having spots. So, one approach would be to model all of those items as entities, many of them as collections, e.g. in a hierarchy of objects.
However, in creating an application, you don't necessarily have to model everything that is in the real world, and, the things you do model don't all have to be first-class entities.
What I'm getting at is that you can model all the spots with a single table having primary key as: lot, level, row, spot, and then with attributes type/size (e.g. compact, handicapped, boat/rv), free/occupied.
A search for an available spot is a query against the table, and an update that marks a spot as free/occupied is a simple transaction.
There are lots of other options: in OOP, you can maintain two simple lists: occupied and non-occupied. The non-occupied list can be broken out into multiple lists by categtories, or maybe even sorted. The manager holding the collection of spots could search and move items between the lists.
In summary, you should study the domain queries and commands beyond the obvious real-world structure of the real-world parking lot. It could be that this extra structure (e.g levels, rows) provides almost no real domain value other than simply identifying where the free spot is. So, there is little reason to organize into multiple tables, and/or, perhaps there is no reason to model a "level" itself as an entity when the level can be captured as a simple (value) attribute.
(There is no way that a parking lot of even tens of thousands of spots would tax a modern computer system, so almost any approach would work. In such case do the simplest as @DocBrown is suggesting. Now, if you were doing hotels, you might reach internet scale, and then eventually you'd have some scaling things to deal with.)
We can never model everything, thus, modeling, by definition, is abstraction, in the sense of hiding irrelevant detail so we can focus on what is truly relevant.
Identify the use cases that are relevant to the domain; from those identify the queries and commands to modify the model — starting with noting well the inputs/givens & outputs/desired results — and from those identify what to model along with the actual queries and commands. With this level of understanding, you will begin to see which modeled entities have what responsibilities and which are merely value attributes. If we model more than necessary, we may loose clarity.
Update for your update: Don't model more than you need. Don't use subclasses when value attributes will do. Don't use object hierarchy when attributes will do.
For example, you're showing modeling the size of the spot using subclassing. What happens when a particular spot is a handicapped spot? Now you need a subclass for each handicapped spot size (e.g. class RVHandicappedSpot). This is class explosion, and a code smell when using classes for modeling things that could otherwise be modeled with attributes.
Further, using attributes you can have numeric ranges rather than only enums, e.g. for the length of a spot. When we model using classes, it constrains us to distinct values more like the equivalent of enums (compared to numbers).
Regarding the bus parking on multiple spots:
Essentially there are two separate problems: identifying the bus parking spots, and allocating them. These can be performed at different times; they do not need to be done together.
I'd suggest you model all potential bus parking spots in advance, as spots that themselves are a collection of other spots. Then, you can determine which of the potential bus parking spots are fully unoccupied, and hand them out as needed. There are a number of considerations here, such as not carelessly hampering bus parking by handing out random car parking spots that belong to the bus parking.
I see the bus parking operations as mostly algorithmic, rather than something solved by a complex data structure. It is similar to register allocation in compiler technology (e.g. graph coloring) when the processor has register pairs, and such.
There are probably three options for checking whether a spot and vehicle match: the Spot can check if a Vehicle fits in it, or a Vehicle can check if a Spot fits it, or a manager (the Lot or even some third party) can check for the match.
Which is best for your domain is a good question to ask.
Some of the criteria for trade offs involve: do either spot or vehicle have specialization (subclasses) to whom question should be delegated. If so they should be consulted. Do either the spot or vehicle have private data that influences matching that cannot be see by the other? If so, they should be given a chance to approve/deny the match.
I might make the bus parking spots a spot subclass that is a collection of spots. In that case, there would be some class hierarchy among kinds of spots, but it is not clear to me whether the generic spot algorithm (based on spot size) is sufficient or a specializing override would be needed for the subclass.
Also, we want a stable interface for the outside consuming clients to use.
So, my first take on that would be that I would have that be the manager's (the Lot's) responsibility so that from an external interface point of view the consuming client code only has to deal with the manager, even as the code evolves internally.
However, the manager may simply choose to delegate to the spot or to the vehicle or both (e.g. both have to say yes, then it is a match).
class ParkingLot {
boolean Matches(Spot spot, Vehicle vehicle) {
return spot.Matches(vehicle) && vehicle.Matches(spot);
}
}
|
Regulation of protein turnover versus growth state: ascites hepatoma as a model for studies both in the animal and in vitro.
Cell protein turnover states as related to growth phase have been analyzed in a rat ascites hepatoma (Yoshida AH-130), which after transplantation entered a period of exponential growth, followed by a quasi-stationary state. Evaluation of AH-130 cell protein turnover in the animal (slow-turnover protein pool) was combined with rapid assays of proteolytic rates of cells transferred in vitro. Protein accumulation in the exponential phase reflected the balance between sustained synthetic rates and relatively low degradative rates. Cessation of growth resulted from convergent reduction of synthesis (from 3.10 to 1.49%/h) and enhancement of protein breakdown (from 0.61 to 1.43%/h). Endogenous proteolytic rates in vitro were very close to the above degradation rates. As shown by incubation with ammonia or other lysosomal inhibitors, the acidic vacuolar pathway for protein degradation, while totally suppressed in exponential tumor cells, was activated in cells from stationary tumors to such an extent that it fully accounted for the enhanced proteolysis. In contrast, energy metabolism inhibitors were effective on cells in either growth state, the residual ongoing proteolysis being similar in both cells. The possible contribution of cell death to activation of the acidic vacuolar proteolysis in stationary tumors is discussed. |
The authors would like to acknowledge support from the Marine Biotechnology Program funded by the Korean Ministry of Land, Transport and Maritime Affairs (MLTM) for the work described in the article by Ahn *et al.* (2011[@bb1]).
|
# CrScreenshotDxe
UEFI DXE driver to take screenshots from GOP-compatible graphic consoles.
[This blog post in Russian](http://habrahabr.ru/post/274463/) explains more, here is just a description and usage.
## Description
This DXE driver tries to register keyboard shortcut (F10) handler for all text input devices. The handler tries to find a writable FS preferring OpenCore root if available, finds primary GOP device, takes screenshot from it and saves the result as PNG files on that writable FS.
The main goal is to be able to make BIOS Setup screenshots for systems without serial console redirection support, but it can also be used to take screenshot from UEFI shell, UEFI apps and UEFI bootloaders.
To start the driver, you can either:
- Install the driver via OpenCore
- Integrate it into DXE volume of your UEFI firmware using [UEFITool](https://github.com/LongSoft/UEFITool) or any other suitable software (don't forget a DepEx section to prevent too early start)
- Add it to an OptionROM of a PCIe device (will try it once I have a device needed)
- Let BDS dispatcher load it by copying it to ESP and creating a DriverXXXX variable
- Load it from UEFI Shell with load command
## Build
It's a normal EDK2-compatible DXE driver, just add it to your package's DSC file to include in the build process.
## Usage
Load the driver, insert FAT32-formatted USB drive and press F10 to take screenshots from primary graphic console available at the moment.
To indicate it's status, the driver shows a small colored rectangle in top-left corner of the screen for half a second.
Rectangle color codes:
- Yellow - no writable FS found, screenshot is not taken
- Red - something went wrong, screenshot is not taken
- Green - screnshot taken and saved to PNG file
|
1. Field of Invention
This invention relates generally to packages for candy pieces, and more particularly to a display package housing a container loaded with candy pieces all having the same figurative form, the package being generally in the shape of a candy piece, but in a greatly enlarged scale.
2. Status of Prior Art
In merchandising, it is a common practice to package candy and other edible products so as to create the impression that the package contains a larger quantity of the product than is actually contained therein. It is for the same reason that many toys are packaged in oversized boxes.
This is not done to deceive children, but to satisfy their desire for sheer bulk. The smaller the child, the greater his play interest in bigness. Also the larger the package, the greater is its display potential.
The present invention is concerned with candy pieces. These are often packaged in a transparent jar or container made of glass or transparent plastic material provided with a screw-on cap which seals the candy pieces loaded in the container so as to exclude contaminants and maintain the pieces in a sterile condition.
A conventional transparent container is not much larger than the load of candy pieces stored therein, and is generally utilitarian in appearance. Hence if a container of this type is put on display on the counter or shelf of a retail store, it does little to attract the attention of a potential purchaser. Moreover, the conventional container for candy pieces, when depleted of these pieces, is usually then discarded, for it has little visual appeal and the owner has no reason to retain it.
Should a manufacturer of candy pieces wish to enhance the attractiveness of the container for these pieces so that the container effectively displays his product, and he provided for this purpose a shaped container molded of synthetic plastic material having a figurative form, then he is faced with the problem of packaging the candy pieces under acceptable sanitary conditions.
Candy pieces are usually produced and packaged in a "clean room" in which the ambient atmosphere is filtered and the workers operate with gloved hands and wear sterile garments. But should the same facility include plastic molding equipment to make the containers which are thereafter filled with the candy pieces, it then becomes difficult to maintain the sterility of the edible product. |
Hyoid osteoradionecrosis accompanied by candida infection.
Osteoradionecrosis of the hyoid bone is a rare complication of therapeutic irradiation performed for head and neck cancer. In this article, we present a 52-year-old male patient who admitted with severe odynophagia following chemo-radiotherapy administration for tonsil carcinoma. Fluorine-18-fluorodeoxy-glucose positron emission tomography-computed tomography revealed a metabolic activity in hyoid bone. The pathological findings were consistent with fungal infection and hyoid bone necrosis. Hyoid osteoradionecrosis should be kept in mind in patients with intractable dysphagia following irradiation for head and neck tumors. |
Bryce Harper does not have any ligament or tendon damage in his injured left knee, but the Washington Nationals star outfielder will be out indefinitely because of a significant bone bruise. Rizzo said the conditions, which included steady rain during the play "aided" in the injury but didn't blame Major League Baseball for going ahead with the game.
Harper sustained the injury in the first inning while rounding first base.
Harper was unable to put weight on his leg and was carried off the field by his hitting coach and the team trainer. "I'm very optimistic that he'll be at least fine shortly", Baker said.
The Nationals and Giants game had already been delayed for several hours due to rain, so Nationals fans were already a little annoyed.
Manager Dusty Baker spoke this week about the importance of new players fitting well into the WashingtonNationals' clubhouse in the middle of the season.
The Nationals placed Harper on the 10-day disabled list with a hyperextended left knee.
Jackson allowed just one run in six innings, Adam Lind was 3 for 3 with an RBI and Ryan Zimmerman had two hits and drove in a run for Washington.
The Giants recalled utilityman Orlando Calixte to be their extra man. Games start at 10:05 a.m. PDT and 4:05 p.m. PDT.
"Today was definitely one of those, dig-deep-and-see-what-you-made-of days", Jackson said.
Washington took three of four in the series and leads second-place Miami by 15 games in the NL East. Samardzija has won three in a row after a 6-3 win versus the Arizona Diamondbacks with all three runs plated over 6.1 frames.
Popular news
USA officials says confrontation with North Korea not imminent
Pompeo declined to say how long it will be before North Korea could carry out such a nuclear attack on the United States mainland. The White House said in a statement that Trump and Xi "agreed North Korea must stop its provocative and escalatory behavior".
Dallas RB Ezekiel Elliott suspended 6 games in domestic case
The drive was set up when Cowboys punt returner Lance Lenoir fumbled a punt to set the Rams up at the Cowboys 33-yard line. The Cowboys threw 41 passes in Elliott's absence, and Darren McFadden was their top ball-carrier with only six rushes.
Tom Cruise Injured During Scary Film Stunt
Chief Christopher McQuarrie is returning for the 6th portion of the establishment, which is set to hit theaters July 27, 2018. However the 55-year-old appears to come up short on the landing and hits the side of the building.
Gold On Verge Of $1300 After North Korea Threats
Ongoing global glut concerns lingered in oil markets despite a bigger-than-expected draw in USA crude inventories. The dollar index, which measures its strength against a basket of currencies, was roughly flat at 93.420.
Bolt injured in relay final
The relay race will be the final event of the evening's proceedings at the penultimate day of the Athletics World Championship. It is also worth mentioning that Saturday's outing was slated to serve as the last race of his career.
CNMI governor backs Trump's stance on North Korea
There's a sense of patriotism among those who cite the island's history of Guam residents serving in the USA military. She called the most recent threats from both sides "dangerous" and said they had heightened tensions in the region.
Tropical Storm Gert expected to form
The depression is now sporting wind speeds of 35 miles per hour and is moving north-northwest at around 14 miles per hour . The National Hurricane Center said Tropical Depression Eight would not threaten the US and stay to the east.
Dow slips 100 points as tensions with N.Korea escalate
The dollar-denominated RTS index was down 1.5 percent at 1,013 points as of 0834 GMT, taking its year-to-date loss to 12 percent. Heading into Thursday, some 89 percent of the companies in the S&P 500 had reported quarterly results.
UK Needs Transition Period To Exit EU
The UK formally triggered the Brexit process on March 29 and divorce negotiations officially began on June 19. We want our economy to remain strong and vibrant through this period of change. |
---
author:
- 'Yutaka Akagi$^1$[^1], Hosho Katsura$^1$, and Tohru Koma$^2$'
title: 'A New Numerical Method for $\mathbb{Z}_2$ Topological Insulators with Strong Disorder'
---
Since the discovery of $\mathbb{Z}_2$ topological insulators by Kane and Mele [@Kane05], many methods have been proposed to compute the $\mathbb{Z}_2$ index. In particular, Fu and Kane found that the calculation of the $\mathbb{Z}_2$ index can be considerably simplified in a system with inversion symmetry [@Fu07]. However, for disordered systems, a numerical determination of the $\mathbb{ Z}_2$ index is still very challenging. Roughly speaking, three types of numerical methods have been proposed so far for this problem:
$\bullet$ The first one was proposed by Kane and Mele themselves [@Kane05], and later some modifications were introduced. Basically, for a given model, the $\mathbb{ Z}_2$ index is defined by a certain Pfaffian with twisted boundary conditions [@Niu85]. The methods were applied to class AII models [@Schnyder08; @Kitaev09; @Ryu10] in two and three dimensions with or without a certain inversion symmetry [@Essin07; @Guo10; @Leung12].
$\bullet$ The second one is based on a scattering matrix theory [@Fulga12]. The $\mathbb{ Z}_2$ indices which are defined by the scattering matrices were numerically computed for models in the classes, AII and DIII, in two and three dimensions [@Fulga12; @Sbierski14].
$\bullet$ The third one was proposed by Loring and Hastings [@Loring10]. The $\mathbb{ Z}_2$ indices are defined by Bott indices which are introduced as an obstruction to approximating almost commuting matrices. For models in the class AII in two and three dimensions, the $\mathbb{ Z}_2$ indices were numerically computed [@Loring10; @Loring15]. For systems with chiral symmetry, Loring and Schulz-Baldes [@Loring17] proposed a numerical method to obtain the values of Bott indices.
In this paper, we propose an alternative method to numerically calculate the $\mathbb{ Z}_2$ indices for disordered topological insulators in arbitrary dimensions. The method is based on the index formulae which were derived in Refs. \[15, 16\]. and has the following two advantages: (i) There is no need to take an average of the $\mathbb{ Z}_2$ index over random variables in a model. (ii) The $\mathbb{ Z}_2$ index is determined by the discrete spectrum of a certain compact operator with a supersymmetric structure. The latter makes it possible to numerically determine the $\mathbb{Z}_2$ index highly efficiently.
Our method is demonstrated for Bernevig-Hughes-Zhang (BHZ) [@Bernevig06; @Yamakage12; @Yamakage13] and Wilson-Dirac [@Wilson74; @Qi08; @Kobayashi13] models whose topological phases are characterized by a $\mathbb{ Z}_2$ index of the class AII in two and three dimensions, respectively. In consequence, the method enables us to determine all of the values of the $\mathbb{ Z}_2$ indices of the strong and weak topological insulators, and the normal insulator phases in the phase diagrams. These values of the $\mathbb{ Z}_2$ indices completely coincide with the predictions in previous studies using a reliable transfer-matrix method [@Yamakage12; @Yamakage13; @Kobayashi13].
To begin with, we introduce two Dirac operators as [@Katsura16a; @Katsura16b] $$\mathcal{D}_{\bm a}({\bm x}) := \frac{x_1 + i x_2 - (a_1 + i a_2)}{| x_1 + i x_2 - (a_1 + i a_2) |}$$ in two dimension (2D), and $$D_{\bm a}({\bm x}) := \frac{1}{|{\bm x} - {\bm a}|} ({\bm x} - {\bm a}) \cdot \mbox{\boldmath $\sigma$}$$ in three dimensions (3D), where ${\bm x} =$ is the position operator and ${\bm a} =$ is a vector for $d=2,3$ \[see Fig. \[Fig:PD\_BHZ\](a)\]. The three-component vector $\mbox{\boldmath $\sigma$}$ is defined by $\mbox{\boldmath $\sigma$}=\mbox{$(\sigma_1, \sigma_2, \sigma_3)$}$ whose components are given by Pauli matrices $\sigma_i$, each of which acts on an auxiliary Hilbert space $\mathbb{C}^2$. The whole Hilbert space is given by the tensor product of the auxiliary $\mathbb{C}^2$ and the original Hilbert space for the Hamiltonian of tight-binding models which we will consider shortly.
Next, we define the $\mathbb{Z}_2$ index for an infinite-volume system which is a tight-binding model on a square $\mathbb{Z}^2$ or cubic lattice $\mathbb{Z}^3$ [@comment]. Let $P_{\rm F}$ be the projection operator onto the states below the Fermi energy $E_{\rm F}$. The difference of two projections is defined as [@Avron94b; @Katsura16b] $$\begin{aligned}
A := \begin{cases}
P_{\rm F} - \mathcal{D}_{\bm a}^* P_{\rm F} \mathcal{D}_{\bm a} & {\rm in \: \: 2D} \\
P_{\rm F} - D_{\bm a} P_{\rm F}D_{\bm a} & {\rm in \: \: 3D},
\end{cases}
\label{eq:A_op}\end{aligned}$$ where $\mathcal{D}_{\bm a}^*$ is the adjoint of the Dirac operator $\mathcal{D}_{\bm a}$. Then, the $\mathbb{Z}_2$ index $\nu$ is defined as $$\begin{aligned}
\nu = {\rm dim} \; {\rm ker}\; (A - 1) \; \; {\rm modulo} \; 2.
\label{eq:Z2-index}\end{aligned}$$ When the Fermi energy $E_{\rm F}$ lies in a spectral gap or a mobility gap, the $\mathbb{Z}_2$ index is known to be well defined [@Katsura16b]. In the following, we will consider such situations.
Now we describe our numerical scheme for calculating the $\mathbb{Z}_2$ index. Let $\Lambda$ and $\Omega$ be two finite regions satisfying $\Omega\subset\Lambda\subset\mathbb{R}^d$ and ${\bm a}\in\Omega$ as in Fig. \[Fig:PD\_BHZ\]. First, we approximate the Fermi projection $P_{\rm F}$ in the infinite volume by the corresponding Fermi projection in the finite region $\Lambda$. More precisely, the approximate one is given by $$\begin{aligned}
P_{\rm F}^{(\Lambda)}:= \sum_{E_n \le E_{\rm F}} \ket{n} \bra{n},\end{aligned}$$ where $\ket{n}$ are eigenstates of the tight-binding Hamiltonian $\mathcal{H}$ on $\Lambda$ which we consider, and we have denoted by $E_n$ the corresponding eigenvalues. To avoid the presence of gapless edge/surface states, we impose periodic boundary conditions for the Hamiltonian in practical numerical calculations. For the operator $A$ in Eq. (\[eq:A\_op\]), we replace the Fermi projection $P_{\rm F}$ by $P_{\rm F}^{(\Lambda)}$, and write $A^{(\Lambda)}$ for the approximate one. Further, we restrict the operator $A^{(\Lambda)}$ to the subregion $\Omega$ as $$\label{AOmegaLambda}
A_{\Omega}^{(\Lambda)} := \chi_\Omega A^{(\Lambda)} \chi_\Omega,$$ where $\chi_\Omega$ is the characteristic function of the subregion $\Omega$.
Under the above gap assumption, the operator $A$ in Eq. (\[eq:A\_op\]) is compact even in the infinite volume limit. Therefore, the spectrum of $A$ is discrete and has no accumulation point except for zero. This implies that an eigenstate of $A$ is localized if the corresponding eigenvalue is not equal to zero. Let $\lambda\ne 0$ be an eigenvalue of $A$. From these observations, it is clear that the eigenvalue $\lambda$ can be approximated by an eigenvalue $\lambda'$ of the approximate operator $A_\Omega^{(\Lambda)}$ if the subregion $\Omega$ is sufficiently large. In addition to this, the cutoff function $\chi_\Omega$ in Eq. (\[AOmegaLambda\]) enables us to remove the boundary effects due to the finite size of the region $\Lambda$.
As the first demonstration, we compute the $\mathbb{ Z}_2$ index of the BHZ model [@Bernevig06; @Yamakage12; @Yamakage13] with disorder on a square lattice $\mathbb{Z}^2$. The Hamiltonian is written as $$\begin{aligned}
\mathcal{H}_{\rm 2D} \! = \! \sum_{\bm x} \! \sum_{k=1,2} \! \bigl[ c^{\dagger}_{\bm x} t_k c_{{\bm x}
+{\bm e}_k} \! + \!{\rm h.c.} \bigr]
\! + \! \sum_{\bm x} c^{\dagger}_{\bm x} (\tau_0 \! \otimes \! \epsilon_{\bm x}) c_{\bm x},
\label{Eq:BHZ}\end{aligned}$$ where $c_{\bm x}=$ , and $c_{{\bm x} i \alpha}$ is the annihilation operator of an electron with spin $\alpha$ and orbital $i$ at site ${\bm x}$. The hopping matrices, $t_1$ and $t_2$, are given by $t_1= g_1\tau_0 \otimes s_3 -\frac{i}{2} g_2 \tau_0 \otimes s_2 + \frac{i}{2} g_3 \tau_2 \otimes s_3$, and $t_2= g_1\tau_0 \otimes s_3 -\frac{i}{2} g_2 \tau_3 \otimes s_1 - \frac{i}{2} g_3 \tau_2 \otimes s_0$, where $\tau_k$ and $s_k$ are Pauli matrices for the orbital and the spin, respectively. Here, $g_1, g_2$ and $g_3$ are real parameters. The on-site potential $\epsilon_{\bm x}$ is given by $\epsilon_{\bm x}=$ , where $W_{\bm x}^{+}$ and $W_{\bm x}^{-}$ are a random potential whose distribution is uniform in the interval with a positive parameter $W$. ${\bm e}_1$ and ${\bm e}_2$ are the unit vectors in the $x$ and $y$ directions, respectively. As is well known [@Bernevig06; @Yamakage12; @Yamakage13], this Hamiltonian (\[Eq:BHZ\]) belongs to the symmetry class AII. We set the Fermi energy which is located at the center of the energy gap.
In the following, we write $\lambda_i$ for the [*i*]{}-th eigenvalue of the operator $A_{\Omega}^{(\Lambda)}$ of Eq. (\[AOmegaLambda\]) in descending order including multiplicity [@comment2]. We note that the spectrum of $A_{\Omega}^{(\Lambda)}$ is included in the interval $[-1,1]$.
Before showing our numerical results, we abbreviate the topological and the ordinary insulator phases as TI and OI, respectively, in the phase diagram [@Yamakage12; @Yamakage13], and write $\nu$ for the value of the $\mathbb{ Z}_2$ index. Figure \[Fig:PD\_BHZ\](c) and (d) show, respectively, $\lambda_1$ and as a function of the mass $\Delta$ and the strength $W$ of disorder. In the region TI, our numerical results are satisfactory because and . Actually, these imply $\nu=1$, i.e., the phase is topological as we expected. In the region OI, $\lambda_1$ is significantly different from 1, and thus $\nu=0$. These results show that the $\mathbb{ Z}_2$ index enables us to distinguish TI from OI. In OI phase, one notices $\lambda_1\simeq\lambda_2\lesssim 0.2$ as seen in Fig. \[Fig:PD\_BHZ\](d). This degeneracy is nothing but a consequence of the two symmetries [@Katsura16a; @Katsura16b], the time-reversal symmetry of the Hamiltonian and the supersymmetric structure of the operator $A$. This kind of degeneracy is very useful to determine the $\mathbb{ Z}_2$ index. In the region $W \lesssim 6$, our results are in good agreement with the previous results [@Yamakage13] which were obtained by using a transfer-matrix method. In the region with a sufficiently large $W$, Anderson localization is expected to occur. For the intermediate critical region between these two regions, our method is not under control because the existence of a significantly nonvanishing spectral or mobility gap cannot be expected. In fact, our numerical results in this region show large fluctuations in both $\lambda_1$ and $\lambda_1-\lambda_2$.
![(Color online). (a) The location of ${\bm a}$ is chosen to be the center of the finite lattice $\Lambda$ of linear size $L$. (b) The subregion $\Omega$ is chosen so that its center is the same as ${\bm a}$ and it does not overlap with the boundary of $\Lambda$. (c) and (d), respectively, show $\lambda_1$ and in the BHZ model as a function of the mass $\Delta$ and the disorder strength $W$. The obtained value $\nu$ of the $\mathbb{Z}_2$ index is indicated in both OI and TI phases. The values of the parameters used are , , , and the system size is . The curves of the phase boundaries with the dots are plotted by using the results in Ref. \[19\]. []{data-label="Fig:PD_BHZ"}](Fig1.eps){width="1.0\columnwidth"}
The second example is the Wilson-Dirac model [@Kobayashi13] with disorder on the cubic lattice $\mathbb{Z}^3$. The Hamiltonian is written as $$\begin{aligned}
\mathcal{H}_{\rm 3D} = \mathcal{H}_{\sf 0} + \mathcal{H}_{\sf hop} + \mathcal{H}_{\sf dis},
\label{Eq:WD}\end{aligned}$$ where $$\begin{aligned}
\mathcal{H}_{\sf 0} \! \! \! \! \! &=& \! \! \! \! \! \sum_{\bm x} \! \! \sum_{k=1,2,3} \! \bigl[\frac{i t}{2} c^{\dagger}_{{\bm x}+{\bm e}_k} {\alpha}_k c_{\bm x}
\! - \! \frac{m_2}{2} c^{\dagger}_{{\bm x}+{\bm e}_k} \beta c_{\bm x} \! + \! {\rm h.c.} \bigr] \notag\\
&+& \! \! \! \! \! (m+3m_2) \sum_{\bm x} c^{\dagger}_{\bm x} \beta c_{\bm x}, \\
\mathcal{H}_{\sf hop} \! \! \! \! \! &=& \! \! \! \! \! \sum_{\bm x} \sum_{k=1,2,3} \bigl[ t_0 c^{\dagger}_{{\bm x}+{\bm e}_k} c_{\bm x} + {\rm h.c.} \bigr], \\
\mathcal{H}_{\sf dis} \! \! \! \! \! &=& \! \! \! \! \! \sum_{\bm x} v_{\bm x} c^{\dagger}_{\bm x} c_{\bm x}.\end{aligned}$$ Here, $c_{\bm x}=$ , the vector ${\bm e}_k$ is the unit vector in $k=x,y,z$ direction, and $\alpha_k =$ , $\beta =$ ; $v_{\bm x}$ is the on-site random potential whose distribution is uniform in the interval with a positive parameter $W$. This Hamiltonian (\[Eq:WD\]) belongs to the symmetry class AII for or . In the following, we will treat the case with .
![(Color online). (a) and (b), respectively, show $\lambda_1$ and in the Wilson-Dirac-type model as a function of the mass parameter $m_0/m_2$ and the disorder strength $W/m_2$. The numerical values $\nu$ of the $\mathbb{ Z}_2$ index are indicated in the phases WTI, STI and OI. The parameters used are , , , and the system size is . The curves of the phase boundaries with the dots are plotted by using the results in Ref. \[22\].[]{data-label="Fig:PD_Wilson-Dirac"}](Fig2.eps){width="1.0\columnwidth"}
Similarly, we abbreviate the weak, strong topological, the ordinary insulator and the diffusive metal phases as WTI, STI, OI, and M, respectively [@Kobayashi13], and write $\nu$ for the value of the $\mathbb{ Z}_2$ index [@comment3]. Figure \[Fig:PD\_Wilson-Dirac\] shows $\lambda_1$ and as a function of the mass parameter $m_0/m_2$ and the strength $W/m_2$ of disorder. In the region OI, $\nu=0$ because . In the region STI, and , and hence $\nu=1$. In the region WTI, but $\lambda_3$ is significantly different from 1 \[see Fig. \[Fig:cross-section\](b)\], and hence $\nu=0$ because the multiplicity of the eigenvalue is two. As for the region M, we cannot expect our method to be effective because the spectral or mobility gap is expected to vanish if the metallic character of the spectrum is true. To summarize, as seen in Fig. \[Fig:PD\_Wilson-Dirac\], our numerical results for the $\mathbb{ Z}_2$ index are in good agreement with the predictions of Ref. \[22\]. In particular, the phase boundaries between WTI and STI, and between STI and OI are considerably sharp. Moreover, although our method is expected to be useless in the metallic phase, there do not appear fluctuations like those in the two-dimensional case.
Although the $\mathbb{Z}_2$ index vanishes in both the OI and WTI phases, there is a definite difference between them as follows: OI phase yields no eigenvalue while WTI phase yields the eigenvalue which is doubly degenerate. If the eigenvalue is related to surface states, one can expect, from our numerical results, that the multiplicity of coincides with the number of Dirac cones which appear on the surface of the system. In fact, it was numerically observed in a generalized Kane-Mele model on a diamond lattice that WTI (STI) phase exhibits two surface Dirac cones (odd number of Dirac cones) [@Fu07b].
![(Color online). (a) $W/m_2$ and (b) $m_0/m_2$ dependences of the eigenvalues $\lambda_i$, $i=1,2,\ldots,5$, of the operator $A_{\Omega}^{(\Lambda)}$ for the system size . (a) and (b) correspond to cross-sections of Fig. \[Fig:PD\_Wilson-Dirac\] for and , respectively. The inset in (a) shows $\lambda_1$ and $\lambda_2$ as a function of the inverse volume of the system ($1/L^3$) for fixed parameters, and . The green (yellow) line is a fit to the numerical data of $\lambda_1$ ($\lambda_2$). []{data-label="Fig:cross-section"}](Fig3.eps){width="0.8\columnwidth"}
Figure \[Fig:cross-section\] shows $W/m_2$ and $m_0/m_2$ dependences of the eigenvalues $\lambda_i$, $i=1,2,\ldots,5$, of the operator $A_{\Omega}^{(\Lambda)}$. According to Ref. \[22\], STI emerges for and for . One can see that $\lambda_1$ is significantly different from $\lambda_2$, and that $\lambda_2$ and $\lambda_3$ are degenerate, and similarly, $\lambda_4$ and $\lambda_5$ are degenerate. As mentioned in the case of two dimensions, this even degeneracy is a consequence of the two symmetries [@Katsura16a; @Katsura16b], the time-reversal symmetry of the Hamiltonian and the supersymmetric structure of the operator $A$. For the region in Fig. \[Fig:cross-section\](a), the diffusive metallic phase appears. In this region, one can see that the above double degeneracy in the spectrum of $A_{\Omega}^{(\Lambda)}$ is lifted due to the vanishing of the spectral or mobility gap in the metallic phase.
The inset of Fig. \[Fig:cross-section\](a) shows system-size dependences of $\lambda_1$ and $\lambda_2$ for fixed parameters and . As the system size increases, $\lambda_1$ and $\lambda_2$ converge to $1$ and about $0.7$, respectively. Thus in the infinite-volume limit, we can clearly conclude that the $\mathbb{ Z}_2$ index $\nu$ is unity. One can perform a similar analysis and extract the eigenvalues of $A$ in the infinite-volume limit for other values of the parameters.
As seen in Fig. \[Fig:cross-section\](b), the double degeneracy of appears in the region of WTI where the corresponding parameter satisfies . Clearly, one can see that $\lambda_3$ is separated from , and hence the $\mathbb{ Z}_2$ index $\nu$ is equal to zero. Thus, if the first and the second eigenvalues, $\lambda_1$ and $\lambda_2$, are degenerate, information about the third eigenvalue $\lambda_3$ is useful to determine the $\mathbb{ Z}_2$ index.
Summary: We have presented our new method for numerically calculating the $\mathbb{ Z}_2$ indices of topological insulators with strong disorder. Our method has the following two advantages: (i) There is no need to take an average of the $\mathbb{ Z}_2$ index over random variables in a model. (ii) The $\mathbb{ Z}_2$ index is determined by the discrete spectrum of a certain compact operator with a supersymmetric structure. These properties make it possible to numerically determine the $\mathbb{Z}_2$ index highly efficiently. In order to check the effectiveness of our method, we have demonstrated that all of the numerical values of the $\mathbb{ Z}_2$ indices completely coincide with the predictions in previous studies using a reliable transfer-matrix method [@Yamakage12; @Yamakage13; @Kobayashi13] for the two-dimensional Bernevig-Hughes-Zhang and the three-dimensional Wilson-Dirac models. Thus, the strong topological insulator phases can be characterized by the $\mathbb{ Z}_2$ index in the index formulae [@Katsura16a; @Katsura16b], and can be clearly distinguished from other phases. We believe that the good agreement between the two different approaches is one of the steps toward the understanding of the nature of $\mathbb{Z}_2$ topological insulators although we cannot definitely compare our method with other approaches mentioned at the beginning of the present paper. Finally, we remark that the generalization of our method to models in other symmetry classes in arbitrary dimensions is straightforward.
[101]{}
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We note that a tight-binding model on an arbitrary lattice in $d$ dimension can be mapped onto the model on $\mathbb{Z}^d$ with suitably chosen hopping integrals.
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Here, $A^{(\Lambda)}$ is expressed in terms of $P_{\rm F}$ and $\tilde{\mathcal{D}}_a({\bm x}) :=$ as $A^{(\Lambda)}=P_{\rm F} - {\tilde {\cal D}}^*_a P_{\rm F} {\tilde {\cal D}}_a$, where ${\mathbb I}_{4}$ is the 4-dimensional identity matrix and $\mathcal{D}_a$ should be thought of as a matrix of dimension $|\Lambda|$.
In this case, the operator $A^{(\Lambda)}$ is written as $A^{(\Lambda)} = \tilde{P}_{\rm F} - \tilde{D}_a \tilde{P}_{\rm F} \tilde{D}_a $, where $\tilde{P}_{\rm F} := P_{\rm F} \otimes {\mathbb I}_{2}$, $\tilde{D}_a({\bm x}) := \sum_{i=1}^3$ , and $D_a^i({\bm x}) := (x_i - a_i)/|{\bm x} - {\bm a}|$. Here, ${\mathbb I}_{2}$ and ${\mathbb I}_{4}$ are the 2- and 4-dimensional identity matrices, respectively. Each operator $D_a^i$ should be thought of as a matrix of dimension $|\Lambda|$.
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[^1]: E-mail address: akagi@cams.phys.s.u-tokyo.ac.jp
|
description et caractéristiques
Three is the magic number. Introducing TRIO. Inspired by our Ambassadors, we set the bar high and the NEW TRIO is the innovative, high performance 3-wheel, premium skate with the option of rocker. Built to be highly versatile and maneuverable, the TRIO is equipped for speed. This skate will take on any adventure. |
Q:
Sql query to get the first 50 person near you
I have users with latitude and longitude.
I want to get the first 50 person based on my location.
for example
CREATE procedure [dbo].[GetProfilesNearBy]
@UserID int,
@UserLat float,
@UserLong float
AS
BEGIN
SELECT TOP 50 * from Users ....
END
GO
where @UserID, @UserLat and @Userlong is the user who send the request
UserLat for example is 31.97542 and UserLong for example is 35.911285
how to get the nearest 50 ?
A:
If you're using SQL Server 2008 or above you could use the geography data type to make it a lot easier:
Example:
DECLARE @user geography = 'POINT(31.97542 35.911285)'
SELECT TOP 50 FROM Users ORDER BY @user.STDistance(Position)
|
The EMBO Journal (2016) 35: 2270--2284
Names are listed according to alphabetical order in author name group
Introduction {#embj201694613-sec-0001}
============
Membrane vesicles carry cargo between cellular organelles, into and out of the cell. In the final step of endocytic vesicle biogenesis, the sides of a tubular membrane are brought into close apposition, leading to an amazing choreography of events, including the recruitment, assembly, and activation of numerous endocytic proteins that ultimately catalyze membrane fission. This process has fascinated cell biologists, biochemists, and physicists alike, due to its central importance to cell function.
In 1989, a GTPase called dynamin was discovered (Shpetner & Vallee, [1989](#embj201694613-bib-0095){ref-type="ref"}) that functions at the heart of endocytic vesicle fission in plant and animal cells. Dynamin possesses the remarkable property of assembling into contractile helical polymers that wrap around the neck of a budding vesicle. The field has focused on how constriction of this helix contributes to severing the membrane to release the vesicle. Experimental validation of this hypothesis was more complex than expected, so many variations to this first, simple constriction model have been proposed and debated to explain exactly how dynamin performs its function.
A large family of related enzymes, including some in prokaryotes, participates in membrane remodeling events. For example, Vps1 in yeast is thought to catalyze fission of endosomal membrane tubes (Chi *et al*, [2014](#embj201694613-bib-0019){ref-type="ref"}) and may, in addition, act in endocytic events (Smaczynska‐de *et al*, [2010](#embj201694613-bib-0097){ref-type="ref"}). Dynamin‐related protein 1 (DRP1) and its yeast homolog DNM1 are key molecules involved in mitochondrial scission (Legesse‐Miller *et al*, [2003](#embj201694613-bib-0049){ref-type="ref"}; Ingerman *et al*, [2005](#embj201694613-bib-0040){ref-type="ref"}; Mears *et al*, [2011](#embj201694613-bib-0061){ref-type="ref"}; Koirala *et al*, [2013](#embj201694613-bib-0045){ref-type="ref"}). The topologically opposite reaction---membrane fusion---is mediated by many dynamin‐like proteins (Praefcke & McMahon, [2004](#embj201694613-bib-0082){ref-type="ref"}; van der Bliek *et al*, [2013](#embj201694613-bib-0006){ref-type="ref"}): Mitofusins drive mitochondrial outer membrane fusion and optic atrophy 1 (OPA1) fusion of the inner membrane (Ban *et al*, [2010](#embj201694613-bib-0003){ref-type="ref"}); atlastins catalyze fusion of the ER membrane (Hu *et al*, [2009](#embj201694613-bib-0039){ref-type="ref"}; Orso *et al*, [2009](#embj201694613-bib-0076){ref-type="ref"}). Most of the dynamin‐like proteins catalyze either fission or fusion, but Vps1, a fission catalyzer, was proposed to be bifunctional and to also catalyze fusion (Peters *et al*, [2004](#embj201694613-bib-0080){ref-type="ref"}). Also in plants, dynamin‐related proteins have been implicated in cell division (Kang *et al*, [2003](#embj201694613-bib-0042){ref-type="ref"}), organelle division (Arimura & Tsutsumi, [2002](#embj201694613-bib-0002){ref-type="ref"}; Gao *et al*, [2003](#embj201694613-bib-0035){ref-type="ref"}; Miyagishima *et al*, [2003](#embj201694613-bib-0070){ref-type="ref"}), and endocytosis (Fujimoto *et al*, [2010](#embj201694613-bib-0033){ref-type="ref"}). In prokaryotes, functions related to the membrane stress response (Sawant *et al*, [2015](#embj201694613-bib-0092){ref-type="ref"}) or the shedding of vesicles to the environment (Michie *et al*, [2014](#embj201694613-bib-0067){ref-type="ref"}) were proposed to rely on dynamin‐related proteins.
After almost 30 years of research on dynamin, recent structural analyses of dynamin family members and *in vivo* and *in vitro* data on dynamin activities help to better understand the mechanism by which dynamin promotes membrane fission. We decided to write this review article with the aim to first present the current state of the field and to then outline where the field is heading and which issues on dynamin function are still being discussed.
What we know: dynamin is a GTP‐dependent fission machine that constricts membrane necks {#embj201694613-sec-0003}
=======================================================================================
Dynamin is a 100 kDa GTPase composed of the GTPase domain, the stalk consisting of a long four helix bundle, a bundle signaling element (BSE), which is a flexible connector between the GTPase domain and the stalk, a phosphoinositide‐4,5‐bisphosphate (PIP~2~)‐binding pleckstrin homology (PH) domain, which is connected to the other tip of the stalk, and a proline‐rich domain (PRD) (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}). Dynamin partners that have SH3 domains bind specifically the PRD. The unstructured PRD is connected to the BSE and extends beyond the GTPase domain. Dynamin has three isoforms in mammals: dynamins 1 and 3, which are highly expressed in neurons, where dynamin 1 represents by far the predominant isoform, and dynamin 2, which is ubiquitously expressed. Most of the findings below have been shown for dynamins 1 and 2.
{#embj201694613-fig-0001}
Dynamins have three well‐established properties. (i) They self‐oligomerize into helices, surrounding a membrane tube. (ii) Nucleotide‐driven conformational changes lead to a constriction of the polymer and of the membrane beneath. (iii) Dynamins induce fission of the membrane necks in a manner dependent on GTP hydrolysis.
Below, we briefly describe the major findings related to these three properties.
Dynamin oligomerizes at the surface of membranes into helices {#embj201694613-sec-0004}
-------------------------------------------------------------
The first essential property of dynamin is its capacity to oligomerize into lock‐washer‐like rings or a cylindrical helix (Hinshaw & Schmid, [1995](#embj201694613-bib-0038){ref-type="ref"}). Such oligomers were first observed at the non‐permissive temperature in electron micrographs around the neck of plasma membrane buds in the temperature‐sensitive *shibire* mutant in *Drosophila* (Koenig & Ikeda, [1989](#embj201694613-bib-0044){ref-type="ref"}). These structures were shown to be made of dynamin by immune staining of synaptosomes treated with GTPγS (Takei *et al*, [1995](#embj201694613-bib-0104){ref-type="ref"}). This oligomerization explains the membrane tubulation activity of dynamin (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Takei *et al*, [1999](#embj201694613-bib-0106){ref-type="ref"}), as well as the property to associate with tubular templates, such as narrow membrane tubes (Roux *et al*, [2010](#embj201694613-bib-0091){ref-type="ref"}), microtubules (Shpetner & Vallee, [1989](#embj201694613-bib-0095){ref-type="ref"}), and lipid nanorods (Stowell *et al*, [1999](#embj201694613-bib-0100){ref-type="ref"}; Marks *et al*, [2001](#embj201694613-bib-0056){ref-type="ref"}), which facilitate its assembly. This tubulation activity of dynamin is proposed to promote membrane curvature at the endocytic pits, as clathrin‐coated pit necks are larger when dynamin recruitment is inhibited (Shupliakov *et al*, [1997](#embj201694613-bib-0096){ref-type="ref"}; Newton *et al*, [2006](#embj201694613-bib-0074){ref-type="ref"}). Dynamin oligomerization in solution is favored by binding to non‐hydrolyzable analogs of GTP, such as GMPPCP, GTPγS (Warnock *et al*, [1996](#embj201694613-bib-0110){ref-type="ref"}), or GDP•$\text{AlF}_{4^{-}}$ (Carr & Hinshaw, [1997](#embj201694613-bib-0013){ref-type="ref"}), while GTP hydrolysis favors disassembly of the dynamin oligomers and release of its subunits from the membrane (Warnock *et al*, [1996](#embj201694613-bib-0110){ref-type="ref"}; Marks *et al*, [2001](#embj201694613-bib-0056){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}).
In the absence of nucleotide, dynamin assembles into a helical coat of 50 nm outer diameter with a helical pitch between 10 and 20 nm (see Figs [1](#embj201694613-fig-0001){ref-type="fig"} and [2](#embj201694613-fig-0002){ref-type="fig"}), surrounding a membrane tubule of 10 nm radius (at the mid‐plane of the membrane) (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Takei *et al*, [1998](#embj201694613-bib-0105){ref-type="ref"}, [1999](#embj201694613-bib-0106){ref-type="ref"}; Chen *et al*, [2004](#embj201694613-bib-0017){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}). The polymer has an outer diameter of approximately 50 nm, with a helical pitch between 10 and 20 nm (see Figs [1](#embj201694613-fig-0001){ref-type="fig"} and [2](#embj201694613-fig-0002){ref-type="fig"}). Cryo‐EM revealed that the dynamin polymer unit is an anti‐parallel dimer, with the GTPase domains facing outside and the PH domains on the inside, bound to the membrane (Zhang & Hinshaw, [2001](#embj201694613-bib-0113){ref-type="ref"}; Chen *et al*, [2004](#embj201694613-bib-0017){ref-type="ref"}; Mears *et al*, [2007](#embj201694613-bib-0060){ref-type="ref"}). Crystallographic data also support this picture (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}A). Non‐oligomerizing mutants could be crystallized in an anti‐parallel dimeric form (Faelber *et al*, [2011](#embj201694613-bib-0025){ref-type="ref"}; Ford *et al*, [2011](#embj201694613-bib-0029){ref-type="ref"}). Dimerization is mediated by the stalks, which form a cross (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}A). The two GTPase domains are linked to one side of the cross whose other side is linked to the PH domains. Interactions between the stalk dimers drive the assembly into the helical polymer of the expected size, as seen by molecular dynamics of the assembly process (Faelber *et al*, [2011](#embj201694613-bib-0025){ref-type="ref"}), identification of the position of mutated residues in non‐oligomerizing mutants (Faelber *et al*, [2011](#embj201694613-bib-0025){ref-type="ref"}; Ford *et al*, [2011](#embj201694613-bib-0029){ref-type="ref"}), and structural insight into the tetrameric form of dynamin 3 (Reubold *et al*, [2015](#embj201694613-bib-0087){ref-type="ref"}). Recent quantitative *in vivo* data also show that dynamin polymerizes into oligomers of varying size at the neck of clathrin‐coated pits (Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}; Grassart *et al*, [2014](#embj201694613-bib-0036){ref-type="ref"}).
{#embj201694613-fig-0002}
Even though the exact interactions between subunits are not conserved throughout the dynamin superfamily, the basic assembly properties (formation of helical polymers) are shared by members of the dynamin superfamily from bacteria to mammals, as revealed by structural studies of dynamin‐like proteins such as BDLP, Drp1/Dnm1, and Mgm1/OPA1 (Low & Löwe, [2006](#embj201694613-bib-0054){ref-type="ref"}; Low *et al*, [2009](#embj201694613-bib-0055){ref-type="ref"}; Ban *et al*, [2010](#embj201694613-bib-0003){ref-type="ref"}; Mears *et al*, [2011](#embj201694613-bib-0061){ref-type="ref"}; Abutbul‐Ionita *et al*, [2012](#embj201694613-bib-0001){ref-type="ref"}; Frohlich *et al*, [2013](#embj201694613-bib-0030){ref-type="ref"}).
Dynamin is a GTP hydrolysis‐dependent, membrane fission catalyzer {#embj201694613-sec-0005}
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The essential function of dynamin is to use energy from GTP hydro‐lysis to sever membrane tubules. Fission of clathrin‐coated pits from the plasma membrane is defective at neuronal synapses of mice lacking dynamin 1, or both dynamins 1 and 3 (Ferguson *et al*, [2007](#embj201694613-bib-0027){ref-type="ref"}; Raimondi *et al*, [2011](#embj201694613-bib-0084){ref-type="ref"}) and in embryonic fibroblasts from mice with conditional double (Ferguson *et al*, [2009](#embj201694613-bib-0028){ref-type="ref"}) or triple deletions of dynamin genes (Park *et al*, [2013](#embj201694613-bib-0078){ref-type="ref"}). Mutants with reduced GTPase activity delay or block endocytosis of transferrin (Marks *et al*, [2001](#embj201694613-bib-0056){ref-type="ref"}; Boll *et al*, [2004](#embj201694613-bib-0007){ref-type="ref"}; Song *et al*, [2004](#embj201694613-bib-0099){ref-type="ref"}) and prolong the residence time of clathrin/dynamin at the plasma membrane (Taylor *et al*, [2011](#embj201694613-bib-0107){ref-type="ref"}; Kural *et al*, [2012](#embj201694613-bib-0047){ref-type="ref"}). GTPase‐defective mutants have dominant negative phenotypes when they co‐assemble with wild‐type proteins in overexpression experiments (Damke *et al*, [1994](#embj201694613-bib-0021){ref-type="ref"}).
The mechanism of dynamin‐mediated membrane fission has been studied by reconstitution with purified components. GTP hydrolysis is consistently required for membrane fission in these reconstituted systems (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Roux *et al*, [2006](#embj201694613-bib-0090){ref-type="ref"}; Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Pucadyil & Schmid, [2008](#embj201694613-bib-0083){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}; Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}). Membrane tension, which can be provided by adhesion of the membrane tubes to the substrate, facilitates the reaction (see also below) (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Roux *et al*, [2006](#embj201694613-bib-0090){ref-type="ref"}; Boulant *et al*, [2011](#embj201694613-bib-0009){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}). As in membrane fusion, dynamin‐mediated fission proceeds through a hemi‐fission state where the inner leaflet of the tube disappears (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}B), leaving a connecting neck made of a single lipid monolayer wrapped in a cylindrical micelle (Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}; Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}).
Dynamin helices constrict in the presence of GTP {#embj201694613-sec-0006}
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There is broad agreement that a key property of the dynamin helical oligomer is its ability to constrict in the presence of GTP. *In vivo,* inhibition of dynamin GTPase activity with chemicals or mutants promotes the formation of elongated necks that have a membrane radius of \~10 nm (Takei *et al*, [1995](#embj201694613-bib-0104){ref-type="ref"}; Marks *et al*, [2001](#embj201694613-bib-0056){ref-type="ref"}; Liu *et al*, [2013](#embj201694613-bib-0051){ref-type="ref"}), consistent with the size of oligomers in the absence of nucleotide (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Chen *et al*, [2004](#embj201694613-bib-0017){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Roux *et al*, [2010](#embj201694613-bib-0091){ref-type="ref"}). Membrane tubes enclosed in helices of dynamin are more constricted during GTP hydrolysis (see Fig [2](#embj201694613-fig-0002){ref-type="fig"}) (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}) or in the presence of non‐hydrolyzable GTP analogs (Zhang & Hinshaw, [2001](#embj201694613-bib-0113){ref-type="ref"}; Chen *et al*, [2004](#embj201694613-bib-0017){ref-type="ref"}; Mears *et al*, [2007](#embj201694613-bib-0060){ref-type="ref"}). The most constricted conformation is observed with GTP‐loaded K44A mutant dynamin, which has a reduced affinity for GTP partially inhibiting its GTPase and fission activity. Under these conditions (i.e. super‐saturating concentrations of GTP), K44A dynamin may be trapped in either a GTP bound state or an undefined GTP hydrolysis transition state. The membrane tube that is wrapped by this form of dynamin exhibits an inner luminal radius \< 2 nm (see Fig [2](#embj201694613-fig-0002){ref-type="fig"}) (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}). This super‐constricted state is achieved by assembling into a two‐start helix and is also observed after short‐time reactions containing wild‐type dynamin and GTP (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}). This constriction of the dynamin helix is consistent with a twisting of the helical collar that can be visualized by the rotation of beads attached to the dynamin coat (Morlot *et al*, [2010](#embj201694613-bib-0071){ref-type="ref"}, [2012](#embj201694613-bib-0072){ref-type="ref"}) or from the cryo‐EM structures with 14 subunits per turn without nucleotide (Chen *et al*, [2004](#embj201694613-bib-0017){ref-type="ref"}), 13 with GMP‐PCP (Zhang & Hinshaw, [2001](#embj201694613-bib-0113){ref-type="ref"}), and 11 with K44A and GTP (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}). The same twisting activity could result in the elongation of the pitch observed in cases where the membrane template cannot be constricted (Stowell *et al*, [1999](#embj201694613-bib-0100){ref-type="ref"}; Marks *et al*, [2001](#embj201694613-bib-0056){ref-type="ref"}; Lenz *et al*, [2008](#embj201694613-bib-0050){ref-type="ref"}; Faelber *et al*, [2011](#embj201694613-bib-0025){ref-type="ref"}). This constriction ability seems to be shared among members of the dynamin family, as it is also observed for the dynamin‐related protein, Dnm1 (Mears *et al*, [2011](#embj201694613-bib-0061){ref-type="ref"}).
The properties of dynamin described above are in agreement with the initial constriction model that dynamin breaks membrane by constriction during GTP hydrolysis (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}B). In the first description of this model, the dynamin helix would constrict until the membrane neck reaches the hemi‐fission state and then is fully broken. However, two findings from *in vitro* experiments have been in apparent disagreement with this simplest view. First, constriction of dynamin is necessary, but not sufficient for fission. Second, GTP hydrolysis triggers partial depolymerization of the dynamin coat. In the following, we detail these findings and explain how they set the current debate about the dynamin mechanism.
What is being discussed: reconciling GTP‐driven constriction, disassembly, and mechanics of the membrane {#embj201694613-sec-0007}
========================================================================================================
In this part, we will briefly discuss recent data on the role of mechanics of membrane on the fission reaction, and results on the role of disassembly in fission. Then, we discuss the two models that try to conciliate these data.
Contributions of membrane constriction and tension to fission {#embj201694613-sec-0008}
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The first observations of dynamin‐mediated fission *in vitro* showed that membrane tension was necessary for dynamin to break membranes. Nonetheless, this observation is consistent with the fact that the super‐constricted state of dynamin does not constrict the membrane sufficiently to reach hemi‐fission, leaving a lumen of 1.9 nm radius (see Fig [2](#embj201694613-fig-0002){ref-type="fig"}) (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}): In a case where dynamin would constrict the membrane enough to go beyond the hemi‐fission state and break it completely, membrane tension would have no impact on the fission rate, as a membrane with low tension would be broken as efficiently as a membrane with high tension. However, fission occurs within minutes if membrane tension is low (Pucadyil & Schmid, [2008](#embj201694613-bib-0083){ref-type="ref"}; Dar *et al*, [2015](#embj201694613-bib-0023){ref-type="ref"}), whereas it takes a few seconds when membrane tension is high (Roux *et al*, [2006](#embj201694613-bib-0090){ref-type="ref"}; Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}), showing indeed that tension has a direct impact on fission efficiency. Moreover, upon dynamin‐mediated constriction, the hemi‐fission state is reached stochastically (Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}) and is reversible, suggesting that once constricted, thermal fluctuations of the membrane are needed to reach the hemi‐fission state.
Why would membrane tension be required? The solution came from membrane physics (Kozlovsky & Kozlov, [2003](#embj201694613-bib-0046){ref-type="ref"}): Calculations showed that the elastic energy of a highly constricted membrane neck (down to a lumen of 3 nm, but prior to hemi‐fission) was the same as the elastic energy of the hemi‐fission intermediate. In this case, the calculations predict a low energy barrier, and thus, one expects the system to pass from the super‐constricted to the hemi‐fission state spontaneously and stochastically (i.e., by thermal fluctuation), and to be reversible, as observed by the Frolov group (Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}). From this conceptual framework, one thus expects the fission reaction to be stochastic. Moreover, because the elastic energy of the membrane depends on tension and rigidity, the rate of fission is also expected to depend on both, consistent with the early observation that membrane tension was required for fission (Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Roux *et al*, [2006](#embj201694613-bib-0090){ref-type="ref"}). Quantitative measurements of fission rates with membrane tension and rigidity *in vitro* further confirmed theoretical predictions (Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}). *In vivo*, the fission rate is similar to the fastest *in vitro* values (5--10 s), and the distribution is also stochastic (Merrifield *et al*, [2005](#embj201694613-bib-0065){ref-type="ref"}; Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}). Importantly, consistent with the role of membrane elasticity in dynamin‐mediated membrane fission, increased membrane rigidity reduces the rate of fission (Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}), and the presence of polyunsaturated lipids, which reduces membrane rigidity, facilitates fission (Pinot *et al*, [2014](#embj201694613-bib-0081){ref-type="ref"}). Thus, constriction by dynamin may not be sufficient to cause membrane fission, but rather dynamin would constrict the membrane tubule to a size that spontaneously reaches hemi‐fission in a tension and rigidity‐dependent manner.
Nucleotide‐dependent disassembly of dynamin {#embj201694613-sec-0009}
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As early as dynamin was found to oligomerize, it was observed that dynamin oligomers in solution would disassemble upon GTP hydrolysis (Warnock *et al*, [1996](#embj201694613-bib-0110){ref-type="ref"}). This GTP‐triggered disassembly was reported by many techniques (Sweitzer & Hinshaw, [1998](#embj201694613-bib-0103){ref-type="ref"}; Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Pucadyil & Schmid, [2008](#embj201694613-bib-0083){ref-type="ref"}) but was absent in other reports (Stowell *et al*, [1999](#embj201694613-bib-0100){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Roux *et al*, [2006](#embj201694613-bib-0090){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}), even though limited disassembly could not be excluded in these experiments. The discrepancy may reflect the nature of the lipid templates used (their lipid composition and intrinsic curvature), as well as the concentrations of dynamin and assays used to measure disassembly (fluorescence, sedimentation, FRET). Structural studies showing that the GMPPCP‐bound form of a G domain‐GED dimer can be docked into cryo‐EM structures, whereas the $\text{GDP}\! - \!\text{AlF}_{4^{-}}$‐bound state cannot (Chappie, Mears *et al*, [2011](#embj201694613-bib-0061){ref-type="ref"}; Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}), may indicate that the helical scaffold is destabilized in the transition state. Moreover, GTP‐triggered disassembly is consistent with the necessary recycling of dynamin observed *in vivo* (Merrifield *et al*, [2002](#embj201694613-bib-0063){ref-type="ref"}; Doyon *et al*, [2011](#embj201694613-bib-0024){ref-type="ref"}; Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}; Grassart *et al*, [2014](#embj201694613-bib-0036){ref-type="ref"}). It is also consistent with the finding that fission may occur at the tip of the dynamin coat (Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}), which would require that part of the coat be removed prior to fission. Different results have been obtained in a similar assay (Dar *et al*, [2015](#embj201694613-bib-0023){ref-type="ref"}), but because light microscopy was used in both studies, the resolution may be insufficient to draw any clear conclusion.
The current models for dynamin\'s fission mechanisms {#embj201694613-sec-0010}
----------------------------------------------------
### A two‐stage model for dynamin‐catalyzed fission (Fig [3](#embj201694613-fig-0003){ref-type="fig"}A) {#embj201694613-sec-0011}
{#embj201694613-fig-0003}
This model reconciles the fact that dynamin disassembles upon GTP hydrolysis with the need for assembled dynamin to constrict the membrane, by suggesting that these two stages are temporally distinct. Thus, while dynamin scaffolds are needed to constrict the membrane, these same scaffolds could stabilize the underlying tubule and inhibit fission (Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Pucadyil & Schmid, [2008](#embj201694613-bib-0083){ref-type="ref"}; Boucrot *et al*, [2012](#embj201694613-bib-0008){ref-type="ref"}). This model suggests that in stage one, assembled dynamin in a specific nucleotide loaded conformation adopts a super‐constricted state enabling the formation of hemi‐fission intermediates. Based on *in vitro* data discussed above, this likely corresponds to a GDP+Pi transition state (mimicked by GDP•$\text{AlF}_{4^{-}}$ binding), when G domains across adjacent rungs form their highest affinity interactions (Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}). Subsequent release of Pi to the GDP‐bound state would loosen the scaffold, as seen by negative‐stain EM (Stowell *et al*, [1999](#embj201694613-bib-0100){ref-type="ref"}; Danino *et al*, [2004](#embj201694613-bib-0022){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}), allowing for the hemi‐fission intermediates to proceed to complete fission. Importantly, formation of the transition state requires interactions of G domains between adjacent rungs of a dynamin helix. Indeed, *in vitro* (Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}) and *in vivo* (Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}) data suggest that the minimum fission apparatus is slightly larger than one rung in the super‐constricted state (25‐30 monomers, 11 dimers per turn).
The two main points of this model under discussion are the following:
First, the two‐stage model requires that all dimers in a rung are in the same nucleotide state and thus a high degree of cooperativity of the dimers for GTPase hydrolysis. This seems inconsistent with what is known about the GTPase activity of dynamin. The Hill coefficient of dynamin against GTP is one in the assembled state (Tuma & Collins, [1994](#embj201694613-bib-0109){ref-type="ref"}), which means that there is no cooperativity of dimers in GTP hydrolysis. Also, GTPase domains should stay in the transition (GTP+Pi) state long enough for hemi‐fission and fission to occur, which takes 5--10 s, whereas the GTPase rate in the assembled state is a few GTP per second per monomer of dynamin. Thus, the kinetics of dynamin GTP hydrolysis seems inconsistent with the two‐stage model.Second, how induction of hemi‐fission is coupled to disassembly is essential in the two‐stage model, as the super‐constricted state of dynamin does not reach hemi‐fission. The original proposition was that disassembly was fast enough to destabilize the membrane and drive hemi‐fission. However, the membrane is very fluid, with a viscoelastic time less than 10 milliseconds (Camley & Brown, [2011](#embj201694613-bib-0011){ref-type="ref"}). It means that any deformation occurring slower than this time would be followed smoothly by the flow of membrane. No viscoelastic stress will thus appear, and the behavior of the membrane will be dictated by equilibrium mechanics. The dynamin disassembly rate is typically in the order of a few tens to a few hundreds of milliseconds, up to a few seconds to fully disassemble *in vivo* (Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}). This is much slower than the membrane viscoelastic time, and thus, complete disassembly of the dynamin coat circling a non‐hemi‐fissioned tubule of membrane is expected to lead to tubule widening rather than collapse and break.
But other sources of destabilization may be at work (see Fig [3](#embj201694613-fig-0003){ref-type="fig"}A): It was shown that the PH domain of dynamin contains a rather short amphipathic loop that could wedge itself into the membrane to constrict it further (Ramachandran *et al*, [2009](#embj201694613-bib-0085){ref-type="ref"}). Indeed, biochemistry experiments show that the residues of this helix insert deeper in the leaflet in a nucleotide‐dependent manner (Mehrotra *et al*, [2014](#embj201694613-bib-0501){ref-type="ref"}; Mattila *et al*, [2015](#embj201694613-bib-0057){ref-type="ref"}). However, this hypothesis has received some skepticism, as the position of this loop, away from the PIP~2~ binding pocket in the PH structure, does not allow for insertion in the membrane without releasing its link to PIP~2~. Moreover, the loop (a few amino acids) is so short that one can question the fact that it could generate enough curvature to constrict further the membrane.
A solution might come from the fact the PH domains would tilt when dynamin is constricted (Shnyrova *et al*, [2013](#embj201694613-bib-0094){ref-type="ref"}) (see Fig [3](#embj201694613-fig-0003){ref-type="fig"}A). In the super‐constricted state, one PH domain per dimer seems tilted in the cryo‐EM data, which could indeed push the helix further in the leaflet (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}). However, the resolution of the currently available cryo‐EM data is too limited in order to confirm tilting. Whether this loop insertion is sufficient to create curvature, and whether it keeps its link to PIP~2~ is still unclear.
### The constrictase/ratchet model (see Fig [3](#embj201694613-fig-0003){ref-type="fig"}B) {#embj201694613-sec-0012}
The constrictase/ratchet model is a refined constriction model that proposes that dynamin acts as a motor. GTP hydrolysis energy would be spent in mechanical work to slide adjacent turns of the helix. In this model, GTPase domains, which are linking dynamin turns through direct interactions, could act as molecular motors, and by cycles of association/powerstroke/dissociation powered by several GTP hydrolysis cycles (see Figs [3](#embj201694613-fig-0003){ref-type="fig"}B and [4](#embj201694613-fig-0004){ref-type="fig"}B), would trigger relative sliding of the helical turn, leading to constriction and twisting of the helix. This model is analogous to the mechanism of myosin movement on actin filaments, but with dynamin playing the role of myosin and actin at the same time.
{#embj201694613-fig-0004}
The biochemistry of the GTPase activity is indeed consistent with such motor activity: It has a fairly low affinity for nucleotides and a high GTPase rate (at least when activated through assembly) (Praefcke & McMahon, [2004](#embj201694613-bib-0082){ref-type="ref"}). The model is also supported by structural studies: The global architecture of dynamin is very similar to myosin or kinesin: It has a stalk, which is connected to the GTPase domain through a flexible hinge to the BSE. GTP binding was shown to induce trans‐dimerization (between helical turns) of the GTPase domains via an interface across the nucleotide‐binding site (Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}). Structural studies indicated that the BSE senses the nucleotide loading status of the GTPase domain (Chappie *et al*, [2009](#embj201694613-bib-0014){ref-type="ref"}, [2010](#embj201694613-bib-0015){ref-type="ref"}, [2011](#embj201694613-bib-0016){ref-type="ref"}). It adopts an open conformation in the presence of GTP, whereas a 70° rotation to a closed state was observed in the presence of $\text{GDP}\! - \!\text{AlF}_{4^{-}}$ (a transition state analog) or in the absence of nucleotide. This movement could act as a power stroke for dynamin during constriction (Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}; Ford *et al*, [2011](#embj201694613-bib-0029){ref-type="ref"}). This model is also consistent with cryo‐EM studies showing that upon conversion from the non‐constricted to the constricted state, there is a reduction in one dimer per helix turn (from 14 to 13).
However, there are several open questions for this model. First, the structural data obtained by X‐ray diffraction on almost full length (Faelber *et al*, [2011](#embj201694613-bib-0025){ref-type="ref"}; Ford *et al*, [2011](#embj201694613-bib-0029){ref-type="ref"}; Reubold *et al*, [2015](#embj201694613-bib-0087){ref-type="ref"}) or truncated (G domain‐BSE, "G‐G") dynamin constructs (Chappie *et al*, [2010](#embj201694613-bib-0015){ref-type="ref"}) do not perfectly match the cryo‐EM data (see Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}; Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"} for details). In particular, the EM density maps of the stalks do not perfectly fit the stalk dimer observed in all published X‐ray structures. This may indicate conformational rearrangements of the stalks upon oligomerization or flexibility of the stalk assembly not observed in low‐resolution EM data. While the GMPPCP‐bound dimeric form of the G‐G construct can be docked into the cryo‐EM structures, the $\text{GDP}\! - \!\text{AlF}_{4^{-}}$‐bound state cannot. This suggests that the lipid and GMPPCP‐bound constricted dynamin filament features the open BSE conformation. Finally, a super‐constricted state of dynamin has been described which has only 11 dimers per helix turn (Sundborger *et al,* [2014](#embj201694613-bib-0102){ref-type="ref"}). However, in this super‐constricted state, dynamin forms a two‐start helix, for example, there are two parallel helices wrapping around the membrane tubule, resulting in a double rise per helix turn. The relevance of the two‐start helix and its relation to dynamin\'s constriction mechanism is currently under debate.
Also in this model, the number of interacting GTPase domains is critical for force generation. It was shown by two groups (Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}; Grassart *et al*, [2014](#embj201694613-bib-0036){ref-type="ref"}) that *in vivo*, efficient fission could be mediated by at least 26--28 monomers of dynamin, which corresponds to 13--14 dimers. This number corresponds to a single helical turn of dynamin in the non‐constricted state, or to 1.5 turns in the super‐constricted state. It thus suggests that efficient fission can be mediated by 1 to 5 G‐G interactions. Is this sufficient to generate enough force to constrict the tube? Can it generate the enormous torque (approx. 1nN.nm) measured *in vitro* on long dynamin scaffolds (Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"})?
Another problem is the coupling between formation of G‐G links and constriction: To allow for sliding of the turns, the G‐G domains have to be transiently disrupted. If a given proportion of G‐G interacting domains is inactive while others are active (moving), there would be no sliding. This issue may be solved by carefully considering the coupling between GTPase and mechanical cycles of dynamin (see discussion in the next section).
Also, in this model, the constriction force of dynamin probably opposes two resistances: the membrane elasticity, which would tend to widen the tube, and most probably the rigidity of the dynamin coat itself, which counteracts constriction. As shown experimentally, the constriction force is dependent on GTP concentration (Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}), which means that in this model the maximal constriction depends on force and thus on GTP concentration, which may be inconsistent with the well‐defined super‐constricted state. In this case, dynamin would burn GTP to apply a constant force to hold the tube at its maximal radius of constriction until it spontaneously breaks.
Finally, in this model, how disassembly occurs is less clear. Two hypotheses have been suggested: First, once fission has occurred, dynamin could disassemble because the membrane template is gone. Second, as discussed above, the stresses appearing in the dynamin coat under constriction could cause it to break apart. In those two cases, disassembly would be a consequence of fission and/or constriction, and GTP hydrolysis energy would primarily be spent in generating constriction force (mechanical work).
Thus, the field is left with the challenge of discriminating between two apparently opposing models, one in which most of the constriction is achieved during assembly, and GTP hydrolysis destabilizes G‐G dimers to loosen the dynamin scaffold, and a second model where the energy of GTP hydrolysis is spent in mechanical work of interacting GTPase domains, allowing for one turn of the helix to walk on the adjacent one. Of course, the two models may not be mutually exclusive, yet a mechanism consistent with all data has to be found. Clearly, more information is needed regarding how dynamin\'s GTPase cycle is coupled to its activities (assembly/disassembly, membrane interactions, G domain dimerization, conformational changes, etc.) that lead to fission.
What we need to know: what is GTP energy good for and what is the GTPase cycle of dynamin {#embj201694613-sec-0013}
=========================================================================================
The long debate regarding the contributions of dynamin assembly, constriction, and disassembly to fission appears to be close to resolution. The two models discussed above could be discriminated or reconciled by obtaining two important pieces of information: How the GTP hydrolysis energy is spent and whether the super‐constricted state is reached through assembly, or through active constriction of the polymer. In the disassembly model, most of the energy of hydrolysis is used to destabilize the polymer, as for tubulin or actin, and the super‐constricted state/hemi‐fission is reached through assembly in a more curved helix because dimers are in the transition state. In the constrictase model, most of the energy is used to provide mechanical work to slide helical turns and constrict, as for myosin, and the super‐constricted state is reached through multiple rounds of GTP hydrolysis. In the following, we discuss recent findings trying to address this point.
How constricted is the GTP‐loaded state of dynamin? {#embj201694613-sec-0014}
---------------------------------------------------
Jenny Hinshaw and her group have tried to answer this question by studying the constriction of the dynamin helix depending on its nucleotide load. The recent finding that dynamin K44A constricted tubes with GTP, but also dynamin wild‐type tubes with GTP, are in the super‐constricted state suggests that at least at some point in the GTPase cycle assembled dynamin is already in the super‐constricted state (Sundborger *et al*, [2014](#embj201694613-bib-0102){ref-type="ref"}). Moreover, in these cryo‐EM structures, dynamin helices are in fact two‐start helices (which means two helices intertwined together), and it thus seems rather impossible to constrict a one‐start helix into a two‐start helix. Thus, if assembled dynamin in the presence of GTP is super‐constricted, the energy of GTP hydrolysis must be used for something other than constriction, probably disassembly.
However, because this super‐constricted state is only seen in the presence of GTP (no other analogs trigger this state) and because dynamin K44A still has a minimal GTPase and fission activity, it cannot be ruled out that this super‐constricted state is not the result of multiple cycles of GTP hydrolysis, inducing constriction by torsion as proposed by the constriction/ratchet model. An important note is that a two‐start helix would constrict similarly to a one‐start helix. In this case, it would mean that dynamin assembles as a two‐start helix in the presence of GTP, which could be mediated by the formation of TRANS‐tetramer as a nucleus for two‐start helices (see Fig [1](#embj201694613-fig-0001){ref-type="fig"}A), and then, hydrolysis would trigger constriction by torsion.
The mechano‐chemical cycle of dynamin {#embj201694613-sec-0015}
-------------------------------------
In an attempt to determine how the energy from GTP hydrolysis is used, Tom Pollard compared the mechano‐chemical cycles of myosin and dynamin (see Fig [4](#embj201694613-fig-0004){ref-type="fig"}). Pre‐steady state kinetic experiments established the mechanism of myosin by measuring the rate and equilibrium constants for each step in the cycle of interaction with ATP and actin filaments. Much less is known about dynamin, but the two enzymatic cycles seem to have much in common (see Fig [4](#embj201694613-fig-0004){ref-type="fig"}), likely arising from the two enzymes having a common ancestor and sharing structural features.
Sliding of filaments in a muscle sarcomere depends on coupling the ATPase cycle to conformational changes. As illustrated in the lower row of reactions in Fig [4](#embj201694613-fig-0004){ref-type="fig"}A, myosin binds and hydrolyzes ATP rapidly. Hydrolysis is rapidly reversible, and most of the energy from ATP binding and hydrolysis is stored in conformational changes indicated by M\* and M\*\*. Myosin releases the γ‐phosphate slowly and then releases ADP quickly, to restart the cycle. Two of the chemical states (nucleotide‐free myosin and myosin‐ADP) bind strongly to actin filaments (slow dissociation indicated by small downward arrows between the two rows), while myosin‐ATP and myosin‐ADP‐P~i~ dissociate very fast from actin filaments (large arrows pointing down). A large free energy change associated with phosphate dissociation from the actin‐myosin‐ADP‐P~i~ intermediate is coupled to a conformational change that produces force on the actin filament. In muscle, these power strokes are uncoordinated and the force‐producing intermediates have short lifetimes, so most myosins (95%) are dissociated from actin and do not interfere with sliding by the active heads. If the myosin heads were coordinated, the filaments would only slide 5--10 nm per ATPase cycle and the filaments would slide backwards during the times that no heads were attached to actin filaments.
Although dynamin has a GTPase cycle parallel to that of the myosin ATPase cycles (see Fig [4](#embj201694613-fig-0004){ref-type="fig"}B), it superficially appears to differ from myosin and other motor proteins, because it does not act upon a separate filament. Rather, dynamin seems to act upon itself through interactions between GTPase domains on adjacent turns of the polymer, with forces transmitted to the dynamin polymer composed of the stalks and then, ultimately to the underlying membrane.
Figure [4](#embj201694613-fig-0004){ref-type="fig"}B shows what is known about the dynamin mechanochemical cycle. The mechanism involves the GTPase cycles of monomers (bottom row) and dimers (top row) and the formation and dissociation of dimers of each chemical intermediate (vertical arrows, comparable to myosin binding to actin). The analysis is limited by lack of information about some of the parameters, but enough is known to propose general features. Six of the 16 rate constants have been measured \[numerical values indicated (Binns *et al*, [2000](#embj201694613-bib-0005){ref-type="ref"})\], and the values of six more can be estimated from equilibrium constants. The sizes of the blue arrows indicate estimated rates under physiological conditions. Black arrows indicate parameters that have never been measured.
Dynamin monomers bind GTP rapidly, but dissociate GTP faster than motor proteins dissociate ATP (Song & Schmid, [2003](#embj201694613-bib-0098){ref-type="ref"}). Dynamin monomers (G) hydrolyze GTP at \~0.01/s (Binns *et al*, [2000](#embj201694613-bib-0005){ref-type="ref"}; Song & Schmid, [2003](#embj201694613-bib-0098){ref-type="ref"}), much slower than motor proteins. Nothing is known about dissociation of the γ‐phosphate, which is unfortunate, since this reaction is crucial in motor ATPases and other GTPases. However, GDP dissociates rapidly, so it can be assumed that P~i~ does as well. Given physiological concentrations of GTP and GDP, most of monomeric dynamin would have bound GTP in the GT or G\*T states.
Dynamin dimers must use a GTPase cycle (top row of Fig [4](#embj201694613-fig-0004){ref-type="fig"}B) parallel to dynamin monomers. Fortunately, we know the most crucial rate constant, the hydrolysis of GTP, which is 100 times faster for dimers than for monomers. The other rate constants have not been measured.
Only the intermediate shown to form intermolecular dimers in solution had bound GDP•$\text{AlF}_{4^{-}}$ (a stable mimic of GDP•P~i~), but the affinity of this GGD•P dimer is low with a *K* ~d~ of 8.4 μM (Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}). Depending on the association rate constant, this affinity corresponds to a dissociation rate of 10--100/s. GTPase domains in other intermediate states have such lower affinities for each other (*K* ~d~ \> 30 μM) (J. Chappie and F. Dyda, personal communication) that no dimers are detected in solution (Chappie *et al*, [2010](#embj201694613-bib-0015){ref-type="ref"}). Thus, such dimers will dissociate rapidly. Although the high local concentration of assembled dynamin favors association of the GTPase domains, only the GGD•P dimers are expected to be stable enough to support motion.
Given these reaction rates, the pathway through the dynamin GTPase cycle probably goes from nucleotide‐free monomeric GTPase domain (G) to its form associated with GTP (GT), which then hydrolyzes GTP to be in the transition state associated with GDP+Pi (GD•P). In this state, the GTPase domain can dimerize (GGD•P) and perform the powerstroke. The dissociation of dimers to monomers could be either in the GGD•P state or after release of the phosphate (GGD) (see Fig [4](#embj201694613-fig-0004){ref-type="fig"}). Note an important difference from myosin; the GTPase with bound GDP and P~i~ has the highest affinity for itself, whereas the myosin‐ATP and ‐ADP‐P~i~ intermediates have the lowest affinity for actin filaments.
Structural studies indicate that the energy from GTP binding and hydrolysis is most likely used to produce motion during the transition from GGT (GTPase dimer with bound GTP) to GGD•P (GTPase dimer with bound GDP and P~i~) when a large conformational change swings the BSE almost 70° (Chappie *et al*, [2011](#embj201694613-bib-0016){ref-type="ref"}). This event will occur when two GT intermediates are transiently bound together in a GGT dimer. GTP hydrolysis appears to drive both the lever arm motion and stabilize the dimer. This is comparable to the motion of the myosin lever arm composed of the light chain domain, which occurs when the weakly bound A‐MDP intermediate dissociates P~i~. An important parallel with muscle myosin is that the force‐producing intermediates, the strongly bound GG dimers between adjacent turns of the dynamin helix, are transient while the other chemical intermediates are dissociated into monomers that do not interfere with the sliding motion. Verifying this hypothesis should be relatively easy by measuring the missing parameters with pre‐steady state kinetics. Steady state kinetics analyzed with Michaelis--Menten assumptions are unlikely to reveal mechanistic details.
The stochasticity of the fission reaction (Merrifield *et al*, [2005](#embj201694613-bib-0065){ref-type="ref"}; Bashkirov *et al*, [2008](#embj201694613-bib-0004){ref-type="ref"}; Taylor *et al*, [2011](#embj201694613-bib-0107){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}; Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}; Grassart *et al*, [2014](#embj201694613-bib-0036){ref-type="ref"}) and the measured Hill coefficient toward GTP concentration \[value of one (Tuma & Collins, [1994](#embj201694613-bib-0109){ref-type="ref"})\] agrees with the fact that the GTP hydrolysis of GTPase domains in the polymer are not coordinated. The available kinetic data (Fig [4](#embj201694613-fig-0004){ref-type="fig"}B) show that dynamin is not processive, so multiple uncoordinated dynamins must work together to produce force with only a minority producing force at any point in time. This explains why GTP hydrolysis of \~5 dimers is required for membrane fission (Liu *et al*, [2013](#embj201694613-bib-0051){ref-type="ref"}).
More information is also required about the assembly/disassembly cycle, in particular the role of GTP in assembly of a one‐start versus two‐start helix. One possibility is that the interactions between GTPase domains in the GTP bound form allows for the formation of G‐G‐mediated tetramers (TRANS‐tetramer see Fig [1](#embj201694613-fig-0001){ref-type="fig"}A), corresponding to the nucleus of a two‐start helix. However, *in vivo*, the majority of units added to the dynamin polymer at the clathrin‐coated pit are dimers (Cocucci *et al*, [2014](#embj201694613-bib-0020){ref-type="ref"}), even if some tetramers can be seen.
Future directions of the dynamin research {#embj201694613-sec-0016}
=========================================
The role of PRD‐binding dynamin partners, in particular the BAR domain proteins {#embj201694613-sec-0017}
-------------------------------------------------------------------------------
One of the unknowns about dynamin is the precise role in its function played by the proteins that bind to its PRD. Many such binding partners have been identified, most of which bind the PRD via SH3 domains (Ferguson *et al*, [2009](#embj201694613-bib-0028){ref-type="ref"}). These proteins define the context in which dynamin must act by functioning as adaptors to facilitate its membrane recruitment or by coordinating its action with that of other proteins. For example, some SH3 domain‐containing proteins that bind dynamin also bind actin regulatory proteins, signaling proteins, or phosphoinositide metabolizing enzymes. The property of some such membrane adaptor proteins (most prominently endophilin) to recruit both dynamin and synaptojanin (Ringstad *et al*, [1997](#embj201694613-bib-0088){ref-type="ref"}, [1999](#embj201694613-bib-0089){ref-type="ref"}; Milosevic *et al*, [2011](#embj201694613-bib-0068){ref-type="ref"}) is of special interest as it helps coordinate the fission reaction of endocytosis with PI(4,5)P~2~ dephosphorylation. Such reaction could help dissociation of dynamin and other endocytic factors from the membrane after fission.
Several SH3 domain‐containing dynamin interactors also contain a BAR family domain, a membrane binding, and, in some cases, a membrane remodeling module (Takei *et al*, [1999](#embj201694613-bib-0106){ref-type="ref"}; Farsad *et al*, [2001](#embj201694613-bib-0026){ref-type="ref"}; Peter *et al*, [2004](#embj201694613-bib-0079){ref-type="ref"}; Itoh *et al*, [2005](#embj201694613-bib-0041){ref-type="ref"}; Frost *et al*, [2008](#embj201694613-bib-0031){ref-type="ref"}; Mim *et al*, [2012](#embj201694613-bib-0069){ref-type="ref"}). A function of proteins with these modules is to help recruit dynamin and facilitate its polymerization. However, a key open question is whether these proteins also participate directly in the fission reaction either via an effect on the curvature of bilayer or via their interactions with dynamin. Data on this topic are conflicting, as based on *in vitro* studies involving purified proteins and liposomes, both inhibitory and facilitating effects on GTPase activity and on dynamin‐mediated fission have been observed (Farsad *et al*, [2001](#embj201694613-bib-0026){ref-type="ref"}; Peter *et al*, [2004](#embj201694613-bib-0079){ref-type="ref"}; Yoshida *et al*, [2004](#embj201694613-bib-0112){ref-type="ref"}; Meinecke *et al*, [2013](#embj201694613-bib-0062){ref-type="ref"}; Neumann & Schmid, [2013](#embj201694613-bib-0073){ref-type="ref"}). The positive effects may be explained by the property of these proteins to facilitate dynamin assembly because of their dimeric nature (Peter *et al*, [2004](#embj201694613-bib-0079){ref-type="ref"}) and ability to polymerize. The negative effect is likely explained by two mechanism: First, the crescent shape of the BAR domain may block further constriction by dynamin by forming a rigid scaffold of fixed curvature on the membrane (Boucrot *et al*, [2012](#embj201694613-bib-0008){ref-type="ref"}). Second, BAR domain rungs could intercalate between opposing GTPase modules in the dynamin spiral, as shown by unpublished cryo‐EM images by Adam Frost, which explain the reported increase of the dynamin pitch in the presence of BAR proteins (Takei *et al*, [1999](#embj201694613-bib-0106){ref-type="ref"}; Farsad *et al*, [2001](#embj201694613-bib-0026){ref-type="ref"}; Itoh *et al*, [2005](#embj201694613-bib-0041){ref-type="ref"}; Sundborger *et al*, [2011](#embj201694613-bib-0101){ref-type="ref"}). This insertion explains reduced GTPase activity as it disrupts the G domain--G domain interaction necessary for GTP hydrolysis. At high BAR/dynamin ratio, all tested BAR domain proteins have a blocking action on dynamin‐mediated fission (A. Roux, P. De Camilli and A. Frost, unpublished results).
A more precise elucidation of how these BAR domain proteins regulate dynamin fission activity is critically needed. Most of the available data were derived from different assays, with variable stoichiometric ratios between dynamin and BAR domain proteins and most important under cell‐free conditions with purified proteins. These conditions may not faithfully replicate events occurring in living cells.
A functional link between dynamin and actin {#embj201694613-sec-0018}
-------------------------------------------
An important open question is the functional relation of dynamin to actin. In addition to being detected at endocytic clathrin‐coated pits, dynamin is also detected at a variety of sites, primarily involving the Arp2/3 complex--actin network, such as macropinocytosis, cell ruffles, podosomes, invadopodia, and actin comet tails (Ochoa *et al*, [2000](#embj201694613-bib-0075){ref-type="ref"}; McNiven *et al*, [2004](#embj201694613-bib-0059){ref-type="ref"}; Bruzzaniti *et al*, [2005](#embj201694613-bib-0010){ref-type="ref"}). Arp2/3 complex and one of its nucleation‐promoting factors, N‐WASP, are also frequently observed at endocytic clathrin‐coated pits, where they colocalize with dynamin spatially and temporally (Merrifield *et al*, [2002](#embj201694613-bib-0063){ref-type="ref"}, [2004](#embj201694613-bib-0064){ref-type="ref"}, [2005](#embj201694613-bib-0065){ref-type="ref"}; Taylor *et al*, [2011](#embj201694613-bib-0107){ref-type="ref"}) and dynamin clearly controls actin polymerization at sites of endocytosis, at least in some cell types (Taylor *et al*, [2012](#embj201694613-bib-0108){ref-type="ref"}; Grassart *et al*, [2014](#embj201694613-bib-0036){ref-type="ref"}). Colocalization of dynamin with these proteins is mediated at least in part by the dynamin‐binding SH3 domain‐containing proteins, which also bind N‐WASP (Cip4/Fbp17/Toca1 family members) (Frost *et al*, [2009](#embj201694613-bib-0032){ref-type="ref"}), the WAVE complex (Ochoa *et al*, [2000](#embj201694613-bib-0075){ref-type="ref"}), and cortactin (McNiven *et al*, [2000](#embj201694613-bib-0058){ref-type="ref"}; Cao *et al*, [2005](#embj201694613-bib-0012){ref-type="ref"}).
There is evidence suggesting that the colocalization of actin and dynamin at endocytic sites reflects the need for actin‐based force (via actin polymerization or myosin motors) to facilitate dynamin‐dependent fission (Itoh *et al*, [2005](#embj201694613-bib-0041){ref-type="ref"}; Boulant *et al*, [2011](#embj201694613-bib-0009){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}; Messa *et al*, [2014](#embj201694613-bib-0066){ref-type="ref"}). This is consistent with the fact that reduced membrane tension delays fission *in vivo* (Boulant *et al*, [2011](#embj201694613-bib-0009){ref-type="ref"}; Morlot *et al*, [2012](#embj201694613-bib-0072){ref-type="ref"}). This effect could be achieved locally by direct interaction of the dynamin coat with the actomyosin network through PRD‐binding proteins, as the actin cortex is the main membrane tension regulator in the cell. However, the localization of dynamin at other actin rich sites remains without a clear explanation and calls for further studies. For example, recent findings from the Chen laboratory strongly support a role of dynamin in organizing the asymmetrical, actin‐based protrusions that myoblasts use to fuse with myotubes (E. Chen, unpublished). Similar observations have been made for osteoclasts fusion (Shin *et al*, [2014](#embj201694613-bib-0093){ref-type="ref"}).
The dynamin family---similarities and differences {#embj201694613-sec-0019}
-------------------------------------------------
Other members of the dynamin family, such as OPA1 and mitofusin, function in membrane fusion and tubulation rather than membrane fission. The challenge remains to understand how insights into dynamin\'s membrane scission mechanism can be applied to other members of the family to explain fusion and membrane tubulation, in addition to scission.
Extensive crystallographic analyses of GTPase‐BSE constructs in a variety of nucleotide states from Drp1 *Arabidopsis thaliana* AtDRP1A (Chen *et al*, [2012](#embj201694613-bib-0018){ref-type="ref"}), human MxA (Rennie *et al*, [2014](#embj201694613-bib-0086){ref-type="ref"}), and Dnm1 (Kishida & Sugio, [2013](#embj201694613-bib-0043){ref-type="ref"}; Wenger *et al*, [2013](#embj201694613-bib-0111){ref-type="ref"}) support that all of these members share a mechanism of GTP hydrolysis with dynamin---namely, dimerization of the GTPase domains and, likewise, a nucleotide‐dependent conformational change of the BSE. However, further studies will confirm how general this mechanism is.
Comparative analyses of stalk interaction interfaces of close dynamin relatives suggest similar assembly principles but different helical geometries (e.g. helices of increased diameter in the case of Dnm1) that may be adapted for particular cellular functions, such as tubulation of the endosome or mitochondrial constriction. Other family members, such as the mitochondrial fusion dynamins, have predicted all‐helical stalk regions though in general molecular insight into assembly mechanisms and architecture of such assembled structures remains sparse. There is limited understanding of how stimulated nucleotide hydrolysis is converted into a membrane remodeling event for most of the members. It may be expected that appropriate alterations in rates of assembly, hydrolysis, and disassembly can convert a scission dynamin into a longer lived tubulating or fusion dynamin.
Dynamin has unique features compared to all other members of its family: most prominently, its PH domain and PRD. Absence of these would require an alternative mechanism for recruitment, association/interaction with target membranes, and, potentially, participation in scission (see above). Drp1 (higher eukaryotes)/Dnm1 (fungi) have, in place of a PH domain, an "Insert B" region of low sequence complexity. In these cases, membrane recruitment is therefore outsourced to accessory factors. Drp1 can be independently recruited by MFF and, separately, by the closely related proteins MiD49, MiD51 although the functional consequences of recruitment by either pathway may differ (Gandre‐Babbe & van der Bliek, [2008](#embj201694613-bib-0034){ref-type="ref"}; Koirala *et al*, [2013](#embj201694613-bib-0045){ref-type="ref"}; Palmer *et al*, [2013](#embj201694613-bib-0077){ref-type="ref"}; Liu & Chan, [2015](#embj201694613-bib-0052){ref-type="ref"}; Loson *et al*, [2015](#embj201694613-bib-0053){ref-type="ref"}). In yeast, Dnm1 is recruited by Fis1 and the adaptors Mdv1 and Caf4 (Lackner *et al*, [2009](#embj201694613-bib-0048){ref-type="ref"}; Guo *et al*, [2012](#embj201694613-bib-0037){ref-type="ref"}). BDLP has a "paddle" where dynamin has a PH domain. The paddle has a number of hydrophobic residues that are required for membrane interaction (Low *et al*, [2009](#embj201694613-bib-0055){ref-type="ref"}). An alternative solution is exhibited by the mitofusins (mammals), Fzo1 (fungi), atlastins, and some forms of OPA1 and Mgm1 (mammals/fungi), which are membrane‐anchored via transmembrane segments.
Conclusions {#embj201694613-sec-0020}
===========
This review emphasizes large areas of consensus, but also the remaining issues to solve for a complete understanding of dynamin mechanism. We also propose approaches that need to be taken to resolve these issues. Yet, the synthesis of 30 years of work on dynamin allows us to be optimistic, and already, we can state that many aspects of dynamin‐mediated membrane fission have been understood. As the prototypic member of a large family of related GTPases that catalyzes both fission and fusion, we hope that the current and future knowledge acquired on the mechanism of dynamin‐catalyzed fission will aid our understanding of multiple cellular fission and fusion reactions.
Conflict of interest {#embj201694613-sec-0021}
====================
The authors declare that they have no conflict of interest.
[^1]: Based on discussions that happened during a meeting organized at the Les Treilles foundation, Tourtour, France, Aurélien Roux coordinated the writing of this review.
|
I'm trying to watch today, and I'm just not into it. And I realize I say it ad nauseum, but Alison Sweeney is just terrible. Some days are worse than others, and today was a worse day. But I am loling at her not being able to decide how she's going to pronounce "aunt." I'm really being pulled away from this show because very few of the relationships and rivalries feel real.
LOL - yes. She went through like three variations of ant, auntie, ahnt, etc. And what did you think of her acting standing in the background as Gabi spoke with her mother? It just looked like all this pantomiming to me. With very loud, broad "What? What is she saying? What is going on? Huh? what?" gestures. Like bad elementary-school play acting. I lol'ed so hard - nice comic relief, that one provides - not sure how intentional the funnies are though. |
Clinical Case Reports 2017; 5(12): 2022--2024
A 29‐year‐old man was admitted for out‐of‐hospital cardiac arrest related to ventricular fibrillation (VF) that was successfully terminated after cardiopulmonary resuscitation and one external biphasic shock at 200 J. Ventricular fibrillation occurred while the patient was having lunch. The patient had no past medical record and no familial history of sudden cardiac death.
On admission, ECG revealed sinus rhythm with incomplete right bundle branch block and no evidence of cardiac ischemia or channelopathy (Fig. [1](#ccr31198-fig-0001){ref-type="fig"}, panel A). Coronary angiography and transthoracic echocardiography were normal. Flecainide challenge (1.6 mg/kg, i.e. 150 mg over 10 min) did not unmask Brugada pattern (Fig. [1](#ccr31198-fig-0001){ref-type="fig"}, panel B), and isoproterenol provocation testing (45 μg/min over 3 min) did not induce ventricular arrhythmias. Treadmill testing was unremarkable. Given resuscitated cardiac arrest with documented VF, a subcutaneous implantable cardioverter defibrillator (EMBLEM™ S‐ICD) was implanted. At 4‐month follow‐up visit, ECG revealed typical Brugada pattern (Fig. [2](#ccr31198-fig-0002){ref-type="fig"}, panel A) and 2 months later, the patient experienced VF recurrence during nighttime that was successfully converted to sinus rhythm after one internal shock at 80 J (Fig. [2](#ccr31198-fig-0002){ref-type="fig"}, panel B). Hydroxyquinidine was started at a daily dose of 300 mg.
{#ccr31198-fig-0001}
{#ccr31198-fig-0002}
This case evidences that a negative flecainide challenge does not rule out Brugada syndrome even in the presence of aborted cardiac arrest as the first manifestation of the disease. This is of crucial importance as recognition of Brugada syndrome should lead to familial screening and recommendations concerning lifestyle changes.[1](#ccr31198-bib-0001){ref-type="ref"} Reported incidence of negative response to flecainide challenge in patients with definite Brugada syndrome varies between 14.5 and 32 percent of which approximately 50 percent are symptomatic.[2](#ccr31198-bib-0002){ref-type="ref"}, [3](#ccr31198-bib-0003){ref-type="ref"} However in these studies, syncope but not aborted cardiac arrest was the clinical manifestation of the disease. Moore et al.[4](#ccr31198-bib-0004){ref-type="ref"} reported a possible late diagnosis of Brugada syndrome in a patient with previous cardiac arrest and a negative flecainide challenge, but electrical changes were documented 9 years after the event and were based on electrograms recorded before and briefly after defibrillation testing. When compared to flecainide, ajmaline has been reported to be more effective in unmasking Brugada pattern on the ECG and this difference has been linked to less ajmaline‐induced I~to~ inhibition.[2](#ccr31198-bib-0002){ref-type="ref"} Yet, higher diagnostic value of ajmaline challenge compared to flecainide remains uncertain as it has not been confirmed in larger population studies.[5](#ccr31198-bib-0005){ref-type="ref"} We did not perform ajmaline challenge on initial evaluation, but ECG at 4‐month follow‐up and recurrent VF unambiguously demonstrated a malignant form of Brugada syndrome. The main limitation of this case report lies in the absence of ECG recordings with the right precordial leads placed at the 2nd or 3rd intercostal spaces either at baseline or during the flecainide challenge. Indeed positioning the right precordial leads upwardly can unmask Brugada ECG pattern. However, as type I Brugada ECG pattern became evident at 4‐month follow‐up visit while the right precordial leads were placed at the 4th intercostal space, we believe the absence of Brugada ECG pattern during the flecainide challenge resulted from the imperfect sensitivity of the flecainide challenge rather than from the positioning of the electrodes.
In conclusion, a negative flecainide challenge in a patient experiencing aborted sudden cardiac death is not sufficient to exclude Brugada syndrome and should prompt clinicians to ensure long‐term follow‐up with repeated ECG.
Authorship {#ccr31198-sec-0002}
==========
SC: wrote the manuscript and the revisions. OLV: acquired the data. PC: wrote the manuscript.
Conflict of interest {#ccr31198-sec-0003}
====================
None declared.
|
As a student run organization that recognizes our current criminal justice system does not serve justice for all, we, the Minnesota Public Interest Research Group, are appealing to the ethical and moral responsibility of Sandra Johnson and the City of Bloomington in demanding that they drop the charges against the Mall of America Eleven.
The Minnesota Public Interest Research Group empowers young activists to organize for what we believe in, including working against a justice system built on structural racism. So when a City Attorney exercises their “prosecutorial discretion” to charge organizers, many of whom are of color, the very fabric of our mission is being targeted. The purpose of the Black Christmas demonstration was to protest institutions, upheld by the law, that have protected the guilty and failed the innocent. When we don’t indict those clearly responsible, when we threaten peaceful assemblers, when we charge racial justice organizers for highlighting injustices, we stand on the wrong side of history and threaten the very moral fabric of our country.
We must concede that, on some points, Sandra Johnson is absolutely right. Prosecutors are sworn to uphold the Constitution and the law even-handedly, and it is unethical to use prosecutorial discretion to selectively charge or not charge individuals. Unfortunately, Sandra Johnson does not seem to realize that her selective prosecution of eleven organizers is the exact type of unethical conduct she purports to be avoiding. Selectively targeting eleven out of the thousands of participants and dozens of organizers of the event is not only unethical, it is clearly using prosecutorial discretion to benefit and uphold a system built on white supremacy and racism. By choosing to “send a message” to organizers, instead of applying the same standards to all who joined in the demonstration, Sandra Johnson joins the ranks of many prosecutors before her who have opted to hide behind racist systems of power instead of standing for justice.
This is far from the first time intimidation tactics have been used to repress young people of color organizing against the injustices of the law. We stand on the shoulders of the generations before us who have fought for their freedom and paved the way for us to do the same. It is our duty – as people who love the liberty, freedom, and justice our country represents – to fight and ensure that these rights are inalienable for all people.
We are proud to stand by the Mall of America Eleven and urge the City of Bloomington to drop these overzealous charges before this trial tarnishes the American judicial system even further. Expect to see us tomorrow morning, 8:30AM at the Hennepin County Building in Edina. |
Wireless or Personal Communication Service (PCS) providers have been, until recently, able to store and maintain subscriber information and current location data on only one home location register (HLR). However, due to the escalating number of subscribers and the rapid expansion of the wireless (PCS) communications networks, it has become necessary to employ multiple home location registers to accommodate the growth.
By using multiple home location registers in the wireless communications network, it becomes necessary to devise a system and method to route the query messages and location updates to the proper home location register. A proposed solution is to provide a database in the service control point (SCP) in the telecommunications network, which maintains routing information. However, a serious drawback with this solution is the additional traffic it may cause in the signaling system no. 7 (SS7) network by routing these additional queries from the mobile switching centers (MSCs) to the service transfer points (STPs) and then to the service control point. These queries add to the existing signaling traffic that accomplish toll-free calling, number portability, and other global title translation (GTT) queries to provide services such as line information database (LIDB) services, switch based services (SBS) such as certain Bellcore's CLASS (R) services, calling name (CNAM) delivery, and interswitch voice messaging (ISVM). Due to the anticipated large overall query volume, the SS7 link set between the service control point and signal transfer point becomes a troublesome bottleneck, creating a potentially substantial negative imp act to the network's ability to route calls and provide services. |
---
abstract: |
A turbulent-laminar banded pattern in plane Couette flow is studied numerically. This pattern is statistically steady, is oriented obliquely to the streamwise direction, and has a very large wavelength relative to the gap. The mean flow, averaged in time and in the homogeneous direction, is analysed. The flow in the quasi-laminar region is not the linear Couette profile, but results from a non-trivial balance between advection and diffusion. This force balance yields a first approximation to the relationship between the Reynolds number, angle, and wavelength of the pattern. Remarkably, the variation of the mean flow along the pattern wavevector is found to be almost exactly harmonic: the flow can be represented via only three cross-channel profiles as ${{\bf U}}(x,y,z) \approx {{\bf U}}_0(y) +
{{\bf U}}_c(y) \cos(kz) + {{\bf U}}_s(y)\sin(kz)$. A model is formulated which relates the cross-channel profiles of the mean flow and of the Reynolds stress. Regimes computed for a full range of angle and Reynolds number in a tilted rectangular periodic computational domain are presented. Observations of regular turbulent-laminar patterns in other shear flows – Taylor-Couette, rotor-stator, and plane Poiseuille – are compared.
bibliography:
- 'bands.bib'
date: '?? and in revised form ??'
title: |
Mean Flow of Turbulent-Laminar Patterns\
in Plane Couette Flow
---
Introduction
============
Pattern formation is associated with the spontaneous breaking of spatial symmetry. Many of the most famous and well-studied examples of pattern formation come from fluid dynamics. Among these are the convection rolls which spontaneously form in a uniform layer of fluid heated from below and the Taylor cells which form between concentric rotating cylinders. In these cases continuous translational symmetries are broken by the cellular flows beyond critical values of the control parameter – the Rayleigh number or Taylor number.
A fundamentally new type of pattern has been discovered in large-aspect-ratio shear flows in recent years by researchers at GIT-Saclay [@Prigent_arxiv; @Prigent_PRL; @Prigent_PhysD; @Prigent_IUTAM; @Bottin_EPF]. Figure \[fig:experiment\] shows an example from plane Couette experiments performed by these researchers. One sees a remarkable spatially-periodic pattern composed of distinct regions of turbulent and laminar flow. The pattern itself is essentially stationary. The pattern wavelength is large compared with the gap between the plates and its wavevector is oriented obliquely to the streamwise direction.
The pattern emerges spontaneously from featureless turbulence as the Reynolds number is [*decreased*]{}. This is illustrated in figure \[fig:R350isbanded\] with time series from our numerical simulations of plane Couette flow for decreasing Reynolds number (conventionally defined based on half the velocity difference between the plates and half the gap). At Reynolds number 500, the flow is uniformly turbulent. Following a decrease in the Reynolds number below 400 (specifically 350 in figure \[fig:R350isbanded\]) the flow organises into three regions of relatively laminar flow and three regions of more strongly turbulent flow. While the fluid in the turbulent regions is very dynamic, the pattern is essentially steady.
Shear flows exhibiting regular coexisting turbulent and laminar regions have a been known for many years. In the mid 1960’s, a state known as spiral turbulence was discovered [@Coles; @vanAtta; @ColesvanAtta] in counter-rotating Taylor-Couette flow. Consisting of a turbulent and a laminar region, each with a spiral shape, spiral turbulence was further studied in the 1980s [-@Andereck; -@Hegseth]. Experiments by the Saclay researchers [@Prigent_arxiv; @Prigent_PRL; @Prigent_PhysD; @Prigent_IUTAM] in a very large aspect-ratio Taylor-Couette system have shown that the turbulent and laminar regions in fact form a periodic pattern, of which the original observations of Coles and van Atta comprised only one wavelength. Analogues of these states occur in other shear flows as well. [@Cros] discovered large-scale turbulent spirals in the shear flow between a stationary and a rotating disk. [-@Tsukahara] observed oblique turbulent-laminar bands in plane Poiseuille flow. A unified Reynolds number based on the shear and the half-gap can be defined for these different flows [@Prigent_PhysD] and is described in the Appendix. When converted to comparable quantities in this way, the Reynolds-number thresholds, wavelengths, and angles are similar for all of these turbulent patterned flows. The patterns are always found near the minimum Reynolds numbers for which turbulence can exist in the flow.
In this paper we present a detailed analysis of these turbulent-laminar patterns. We will focus on a single case – the periodic pattern at Reynolds number 350. From computer simulations, we obtain the flow and identify the symmetries of the patterned state. We consider in detail the force balance responsible for maintaining the pattern. From the symmetries and harmonic content we are able to reduce the description to six ordinary-differential equations which very accurately describe the patterned mean flow.
![Photograph of a turbulent-laminar pattern in plane Couette flow from the Saclay experiment. Light regions correspond to turbulent flow and dark regions to laminar flow. The striped pattern of alternating laminar and turbulent flow forms with a wavevector ${\bf k}$ oblique to the streamwise direction. The wavelength is approximately 40 times the half-gap between the moving walls. The lateral dimensions are 770 by 340 half-gaps and the Reynolds number is $Re=385$. Figure reproduced with permission from Prigent [[*et al.*]{}]{}[]{data-label="fig:experiment"}](Figures/prigent_bands_1.ps "fig:"){width="8cm"} ![Photograph of a turbulent-laminar pattern in plane Couette flow from the Saclay experiment. Light regions correspond to turbulent flow and dark regions to laminar flow. The striped pattern of alternating laminar and turbulent flow forms with a wavevector ${\bf k}$ oblique to the streamwise direction. The wavelength is approximately 40 times the half-gap between the moving walls. The lateral dimensions are 770 by 340 half-gaps and the Reynolds number is $Re=385$. Figure reproduced with permission from Prigent [[*et al.*]{}]{}[]{data-label="fig:experiment"}](Figures/exp_labels.eps "fig:"){width="2.3cm"}
![Space-time plot from numerical simulations of plane Couette flow showing the spontaneous formation of a turbulent-laminar pattern at $Re=350$. The kinetic energy in the mid-plane is sampled at 32 equally spaced points along an oblique cut (in the direction of pattern wavevector) through three wavelengths of the pattern. At time zero, $Re=500$ and the flow is uniformly turbulent. Over about 3000 time units $Re$ is decreased in steps to 350, and then held constant.[]{data-label="fig:R350isbanded"}](Figures/space_time.eps){width="8cm"}
Preliminaries
=============
Geometry
--------
The unusual but key feature of our study of turbulent-laminar patterns is the use of simulation domains aligned with the pattern wavevector and thus tilted relative to the streamwise-spanwise directions of the flow. Figure \[fig:domains\] illustrates this and defines our coordinate system. In figure \[fig:domains\](a) a simulation domain is shown as it would appear relative to an experiment, figure \[fig:experiment\], in which the streamwise direction (defined by the direction of plate motion) is horizontal. The near (upper) plate moves to the right and the far (lower) plate to the left in the figure. As we have discussed in detail [@Barkley_PRL; @Barkley_IUTAM], simulating the flow in a tilted geometry has advantages in reducing computational expense and in facilitating the study of pattern orientation and wavelength selection. The important point for the present study is that the coordinates are aligned to the patterns. The $z$ direction is parallel to the pattern wavevector while the $x$ direction is perpendicular to the wavevector (compare figure \[fig:domains\](a) with figure \[fig:experiment\]).
Figures \[fig:domains\](b) and (c) show the simulation domain as it will be oriented in this paper. In this orientation the streamwise direction is tilted at angle $\theta$ (here $24^\circ$) to the $x$ direction. This choice of angle is guided by the experimental results and by our previous simulations. (In past publications [@Barkley_PRL; @Barkley_IUTAM] we have used un-primed $x-z$ coordinates for those aligned along spanwise-streamwise directions and primes for coordinates tilted with the simulation domain. Here we focus exclusively on coordinates fixed to the simulation domain and so for convenience denote them without primes.) In these tilted coordinates, the streamwise direction is $${{\bf e_x}}\cos\theta +{{\bf e_z}}\sin\theta \equiv \alpha {{\bf e_x}}+ \beta{{\bf e_z}}\label{eq:streamwise}$$ where $$\alpha \equiv \cos\theta = \cos(24^\circ)=0.913, ~~~~~~~
\beta \equiv \sin\theta = \sin(24^\circ)=0.407.
\label{eq:alphabeta}$$
We take $L_x=10$, for the reasons explained in [@Jimenez; @Hamilton; @Waleffe_03; @Barkley_PRL; @Barkley_IUTAM]. Essentially, $L_x \sin\theta$ must be near 4 in order to contain one pair of streaks or spanwise vortices, which are necessary to the maintenance of low Reynolds number wall-bounded turbulence. Although our simulations are in a three-dimensional domain, we will average the results in the homogeneous $x$ direction, as will be explained in section \[sec:average\]. For most purposes it is sufficient to view the flow in the $z-y$ coordinates illustrated in figure \[fig:domains\](c). The midplane between the plates corresponds to $y=0$.
The length $L_z$ of our computational domain is guided by the experimental results and by our previous simulations. One of the distinctive features of the turbulent-laminar patterns is their long wavelength relative to the gap between the plates. A standard choice for length units in plane Couette flow is the half-gap between the plates. In the simulation with $L_z=120$ and $\theta=24^\circ$ shown in figure \[fig:R350isbanded\], a pattern of wavelength 40 emerged spontaneously from uniform turbulence when the Reynolds number was lowered to $Re=350$. For this reason, the simulations we will describe below are conducted with $L_z=\lambda_z=40$. The corresponding wavenumber is $$k\equiv \frac{2\pi}{40}=0.157.$$ This large wavelength, or small wavenumber, expresses the fact that the pattern wavelength in $z$ is far greater than the cross-channel dimension.
![Computational domain oriented at angle $\theta$ to the streamwise-spanwise directions. The $z$ direction is aligned to the pattern wavevector while the $x$ direction is perpendicular to the pattern wavevector. The turbulent region is represented schematically by hatching. (a) Domain oriented with streamwise velocity horizontal, as in figure \[fig:experiment\]. (b) Domain oriented with $z$ horizontal, as it will be represented in this paper. In (a), (b) the near (upper) plate moves in the streamwise direction; the far (lower) plate in the opposite direction. (c) View between the plates. []{data-label="fig:domains"}](Figures/domains.eps){width="10cm"}
Equations and Numerics {#sec:eqnum}
----------------------
The flow is governed by the incompressible Navier–Stokes equations
&=& -([[**u**]{}]{})[[**u**]{}]{} - p + [\^2]{}[[**u**]{}]{},\
0&=&[[**u**]{}]{}, \[eq:nse\]
where ${{\bf u}}({{\bf x}},t)$ is the velocity field and $p({{\bf x}},t)$ is the static pressure. Without loss of generality the density is taken to be one. The equations have been nondimensionalized by the plate speed and the half gap between the plates. $\Omega$ is the tilted computational domain discussed in the previous section.
No-slip boundary conditions are imposed at the plates and periodic boundary conditions are imposed in the lateral directions. In our coordinates the conditions are
[[**u**]{}]{}(x,y=1,z) & = & ([[**e\_x**]{}]{}+ [[**e\_z**]{}]{})\
[[**u**]{}]{}(x + L\_x,y,z) & = & [[**u**]{}]{}(x,y,z)\
[[**u**]{}]{}(x,y,z + L\_z) & = & [[**u**]{}]{}(x,y,z). \[eq:bcs\]
Linear Couette flow ${{\bf u}}^L$ is a solution to –, which is stable for all ${\mbox{\textit{Re}}}$ and satisfies $${{\boldsymbol{\nabla}}^2}{{\bf u}}^L = ({{\bf u}}^L\cdot{{\boldsymbol{\nabla}}}){{\bf u}}^L = 0$$ In our tilted coordinate system, $${{\bf u}}^L= y({{\bf e_x}}\cos\theta +{{\bf e_z}}\sin\theta) = y(\alpha {{\bf e_x}}+ \beta{{\bf e_z}})
= u^L{{\bf e_x}}+w^L{{\bf e_z}}\label{eq:uL}$$
The Navier-Stokes equations with boundary conditions are simulated using the spectral-element ($x$-$y$) – Fourier ($z$) code [Prism]{} [@Henderson]. We use a spatial resolution consistent with previous studies [@Hamilton; @Waleffe_03]. Specifically, for a domain with dimensions $L_x=10$ and $L_y=2$, we use a computational grid with 10 elements in the $x$ direction and 5 elements in the $y$ direction. Within each element, we use $8$th order polynomial expansions for the primitive variables. In the $z$ direction, a Fourier representation is used and the code is parallelized over the Fourier modes. Our domain with $L_z=40$ is discretized with 512 Fourier modes or gridpoints. Thus the total spatial resolution we use for the $L_x\times L_y
\times L_z = 10\times 2\times 40$ domain can be expressed as $N_x \times
N_{y} \times N_z = 81 \times 41 \times 512 = 1.7\times 10^6$ modes or gridpoints.
Dataset and averaging {#sec:average}
---------------------
The focus of this paper is the mean field calculated from the simulation illustrated by the spatio-temporal diagram in figure \[fig:average\](a). The velocity field in the portion of the domain shows high-frequency and high-amplitude fluctuations, while the flow in the right portion is basically quiescent. We will call the flow on the left turbulent, even though it could be argued that it is not fully developped turbulence. We will call the flow on the right laminar, even though occasional small fluctuations can be seen in this region.
The turbulent-laminar pattern subsists during the entire simulation of $14
\times 10^3$ time units. However the pattern undergoes short-scale “jiggling”, seen particularly at the edges of the turbulent regions, and longer-scale drifting or wandering in the periodic $z$ direction. We seek to describe the field which results from smoothing the turbulent fluctuations, but for which drifting is minimal, by averaging over an appropriate time interval. The desired averaging time interval represents a compromise between the short and long timescales. We have chosen to average the flow in figure \[fig:average\](a) over the shaded time interval $[t,t+T]=[6000,8000]$, during which the pattern is approximately stationary.
The time-averaged flow is homogeneous in $x$-direction. This is illustrated in figure \[fig:average\](b) where we plot one of the velocity components time-averaged flow over the interval $[6000,8000]$. Cuts at different $x$ locations show that there is essentially no variation in the $x$-direction. All other quantities are similarly independent of $x$. It is therefore appropriate to consider mean flows as averages over the $x$ direction as well as over the time.
We define mean flows as
(y,z) & & \_t\^[t+T]{} \_0\^[L\_x]{} [[**u**]{}]{}(x,y,z,t) dx dt\
[p ]{}(y,z) && \_t\^[t+T]{} \_0\^[L\_x]{} p(x,y,z,t) dx dt.
The mean fields obey the averaged Navier-Stokes equations
\[eq:NSavg\] 0&=&-() - ( ) -[p ]{}+ [\^2]{}\
0&=&,
where $${\tilde{{{\bf u}}}}\equiv {{\bf u}}- {\langle {{\bf u}}\rangle}$$ is the fluctuating field and ${\langle}{\rangle}$ denotes $x$-$t$ average. The mean fields are subject to the same boundary conditions as equations . We denote the Reynolds-stress force from the fluctuating field in equations by ${\bf F}$: $${\bf F}\equiv - {\langle}\left({\tilde{{{\bf u}}}}\cdot {{\boldsymbol{\nabla}}}\right) {\tilde{{{\bf u}}}}{\rangle}= - {{\boldsymbol{\nabla}}\cdot}{\langle}{\tilde{{{\bf u}}}}{\tilde{{{\bf u}}}}{\rangle},$$ We shall focus almost exclusively on the difference between the mean flow and linear Couette flow, for which we introduce the notation $${{\bf U}}\equiv {\langle {{\bf u}}\rangle}- {{\bf u}}^L,
\label{eq:UminusC}$$ as well as $P\equiv {\langle}p {\rangle}$.
Letting the components of ${{\bf U}}$ be denoted by $(U,V,W)$ and the components of ${\bf F}$ be denoted by $({F}^U,{F}^V,{F}^W)$, then the averaged Navier-Stokes equations for the deviation from linear Couette flow in component form become
\[eq:RANS\] $$\begin{aligned}
0 &=& -\left(V {\ensuremath{\partial}}_y + (W + \beta y)~ {\ensuremath{\partial}}_z \right) (U + \alpha y)
~~~~~~~~~~+ {\frac{1}{{\mbox{\textit{Re}}}}}({\ensuremath{\partial}}^2_y + {\ensuremath{\partial}}^2_z) U + {F}^U \label{eq:NSavgU} \\
0 &=& -\left(V {\ensuremath{\partial}}_y + (W + \beta y)~ {\ensuremath{\partial}}_z \right) V ~~~~~~~~~~
-{\ensuremath{\partial}}_y P + {\frac{1}{{\mbox{\textit{Re}}}}}({\ensuremath{\partial}}^2_y + {\ensuremath{\partial}}^2_z) V + {F}^V \label{eq:NSavgV}\\
0 &=& -\left(V {\ensuremath{\partial}}_y + (W + \beta y)~ {\ensuremath{\partial}}_z \right) (W + \beta y)
-{\ensuremath{\partial}}_z P + {\frac{1}{{\mbox{\textit{Re}}}}}({\ensuremath{\partial}}^2_y + {\ensuremath{\partial}}^2_z) W + {F}^W \label{eq:NSavgW}\end{aligned}$$ $$\begin{aligned}
0 &=& {\ensuremath{\partial}}_y V + {\ensuremath{\partial}}_z W. \label{eq:RANSdiv}\end{aligned}$$
${{\bf U}}$ is required to satisfy homogeneous boundary conditions at the plates $${{\bf U}}(y=\pm1,z) = {\bf 0}
\label{eq:homogbc}$$ and periodic boundary conditions in $z$.
A system of this type, with three components depending on two coordinates, is sometimes called 2.5 dimensional. The transverse, or out-of-plane flow $U(y,z)$ appears only in the first equation and is effectively a passive scalar advected by the in-plane flow $(V,W)$ and driven by the Reynolds-stress force ${F}^U$. The in-plane flow can be expressed in terms of a streamfunction $\Psi$ where $$V{{\bf e_y}}+W{{\bf e_z}}={{\bf e_x}}\times \nabla \Psi =
-{\ensuremath{\partial}}_z \Psi {{\bf e_y}}+ {\ensuremath{\partial}}_y \Psi {{\bf e_z}}.
\label{eq:definepsi}$$ We shall use both $(U,V,W)(y,z)$ and $(U,\Psi)(y,z)$ to describe the mean flows.
[ ]{}
[ ]{}
![ $U(y,z)$: transverse component of mean flow. $\Psi(y,z)$: streamfunction of in-plane mean flow. A long cell extends from one laminar-turbulent boundary to the other. Gradients of $\Psi$ are much larger in $y$ than in $z$, [i.e.]{} $|W|\gg|V|$. In the laminar region at the center, $W, V\approx 0$. $E_{\rm turb}(y,z)$: mean turbulent kinetic energy $\langle
{\tilde{{{\bf u}}}}\cdot{\tilde{{{\bf u}}}}\rangle/2$. There is a phase difference of $\lambda_z/4=10$ between extrema of $E_{\rm turb}$ and of $U$. $P(y,z)$: mean pressure field. Pressure gradients are primarily in the $y$ direction and within the turbulent region. Color ranges for each field from blue to red: $U$ \[–0.4, 0.4\], $\Psi$ \[0, 0.09\], $E_{\rm turb}$ \[0, 0.4\], P \[0, 0.007\] .[]{data-label="fig:upsikep"}](Figures/average.ps){width="14cm"}
![ $U(y,z)$: transverse component of mean flow. $\Psi(y,z)$: streamfunction of in-plane mean flow. A long cell extends from one laminar-turbulent boundary to the other. Gradients of $\Psi$ are much larger in $y$ than in $z$, [i.e.]{} $|W|\gg|V|$. In the laminar region at the center, $W, V\approx 0$. $E_{\rm turb}(y,z)$: mean turbulent kinetic energy $\langle
{\tilde{{{\bf u}}}}\cdot{\tilde{{{\bf u}}}}\rangle/2$. There is a phase difference of $\lambda_z/4=10$ between extrema of $E_{\rm turb}$ and of $U$. $P(y,z)$: mean pressure field. Pressure gradients are primarily in the $y$ direction and within the turbulent region. Color ranges for each field from blue to red: $U$ \[–0.4, 0.4\], $\Psi$ \[0, 0.09\], $E_{\rm turb}$ \[0, 0.4\], P \[0, 0.007\] .[]{data-label="fig:upsikep"}](Figures/upsikepmake.ps){width="14cm"}
Results
=======
We present a characterisation of the turbulent-laminar pattern at ${\mbox{\textit{Re}}}=350$. We describe in detail the mean flow, its symmetries, and the dominant force balances within the flow. Our goal here is not to consider closures for averaged Navier-Stokes equations (\[eq:RANS\]). We will make no attempt to model the turbulence, [i.e.]{} to relate the Reynolds-stress tensor ${\langle}{\tilde{{{\bf u}}}}{\tilde{{{\bf u}}}}{\rangle}$ to the mean flow ${{\bf U}}$. Instead we use fully resolved (three-dimensional, time-dependent) numerical simulations of the turbulent flow to measure both the mean field ${{\bf U}}$ and Reynolds-stress force ${\bf F}$. From these we extract the structure of these fields and the dominant force balances at play in sustaining turbulent-laminar patterns.
Mean flow {#sec:meanflow}
---------
The mean flow is visualised in figure \[fig:upsikep\] via the transverse, out-of-plane flow $U(y,z)$ and the in-plane streamfunction $\Psi(y,z)$. Recall \[equation \] that these fields are the deviations of the mean flow from linear Couette flow ${{\bf u}}^L$. The mean turbulent kinetic energy $$E_{\rm turb}\equiv\frac{1}{2}\langle {\tilde{{{\bf u}}}}\cdot{\tilde{{{\bf u}}}}\rangle$$ serves to clearly identify the turbulent region. In these and subsequent plots, the middle of the laminar region is positioned at the centre of the figure and the turbulent region at the periodic boundaries of the computational domain. In figure \[fig:upsikep\] (but not in subsequent figures), plots are extended in the $z$-direction one quarter-period beyond each periodic boundary to help visualise the flow in the turbulent region. The pattern wavelength is $\lambda_z=40$, so that $z=30$ and $z=-10$ describe the same point, as do $z=-30$ and $z=10$.
The mean flow can be described as follows. $U$ is strongest in the turbulent-laminar transition regions. In the transition region to the left of centre ($z=-10$) in figure \[fig:upsikep\], $U$ is negative and primarily in the upper half of the channel. To the right of centre ($z=10$), $U$ is positive and is seen primarily in the lower half of the channel. Comparison with turbulent kinetic energy shows that the transverse mean flow $U$ is out of phase with respect to the fluctuating field ${\tilde{{{\bf u}}}}$ by $\lambda_z/4$. This has been seen experimentally by [@ColesvanAtta] and Prigent [[*et al.*]{}]{} ([-@Prigent_PRL], [-@Prigent_PhysD], [-@Prigent_IUTAM]).
The in-plane flow $\Psi$ in figure \[fig:upsikep\] has a large-aspect ratio cellular structure consisting of alternating elliptical and hyperbolic points. The flow around the elliptical points, located in the centre of the turbulent regions, rotates in a counter-clockwise sense, opposing linear Couette flow. In the vicinity of the hyperbolic points, centred in the laminar regions, the in-plane deviation from linear Couette flow is very weak ($W$ and $V$ nearly zero).
Figure \[fig:meanflow\] shows $y$-profiles at four key points equally spaced along the pattern: centre of the laminar region, turbulent-laminar transition region, centre of the turbulent region, and the other turbulent-laminar transition region. While the $V$ profile is plotted, its variation is very small on the scale of $U$ and $W$ and can essentially be used to indicate the axis. Figure \[fig:meanflowwithCou\] shows profiles for the full mean flow ${\langle {{\bf u}}\rangle}= {{\bf U}}+ {{\bf u}}^L$ containing the linear Couette profile.
![ Same as in figure \[fig:meanflow\], but with laminar Couette flow ${{\bf u}}^L$ included.[]{data-label="fig:meanflowwithCou"}](Figures/Meanuvwmc.ps){width="14cm"}
![ Same as in figure \[fig:meanflow\], but with laminar Couette flow ${{\bf u}}^L$ included.[]{data-label="fig:meanflowwithCou"}](Figures/Meanuvw.ps){width="14cm"}
![ Mean velocity components seen in three planes with standard orientation for Couette flow. The turbulent regions are shaded. Top: velocity components in the streamwise-spanwise plane at $y=0.725$ (upper part of the channel). Middle: same except $y=-0.725$ (lower part of the channel). Bottom: flow in a constant spanwise cut. The mean velocity is shown in the enlarged region. []{data-label="fig:coles"}](Figures/coles.ps){width="10cm"}
The $U$ profiles in figure \[fig:meanflowwithCou\] are S-shaped, of the type found in turbulent Couette flow. This is to be expected in the turbulent region, even at these low Reynolds numbers. However, it is very surprising that the $U$ profile in the laminar region is also of this form. In the laminar region, local Reynolds stresses are absent (see figure \[fig:upsikep\]) and so cannot be responsible for maintaining the S-shaped velocity profile in the laminar regions. The other prominent features in figures \[fig:meanflow\] and \[fig:meanflowwithCou\] are the asymmetric profiles at the transition regions.
The relationship between the mean flow field and the regions of turbulence can be seen in figure \[fig:coles\]. Here the flow is shown in the standard orientations. In each view, greyscale indicates the size of the turbulent energy and the arrows show the mean flow within the plane. In the top two views, the flow is shown in the streamwise-spanwise planes located at $y=0.725$ and at $y=-0.725$. The next view shows the flow between the plates, [i.e.]{}in a streamwise-cross-channel plane, and the last shows an enlargement of one of the laminar-turbulent transition regions. Note that the length $L_z=40$ of our tilted computational domain corresponds to a streamwise length of $L_z/\sin\theta = 40/.407=98.3\approx
100$ and to a spanwise length of $L_z/\cos\theta= 43.78$.
The flow in figure \[fig:coles\] can be compared with the mean flow reported by [@ColesvanAtta] in experiments on turbulent spirals in Taylor-Coutte flow. Coles and van Atta measured the mean flow near the midgap between the rotating cylinders and noted an asymmetry between the mean flow into and out of turbulent regions. They found that the mean flow into turbulent regions was almost perpendicular to the turbulent-laminar interface whereas flow out of the turbulent region was almost parallel to the turbulent-laminar interface. We also observe a striking asymmetry between the mean flow into and out of the turbulent regions. The orientation of our mean flow does not agree in detail with that of Coles and van Atta, but this is most likely due to the fact that Coles and van Atta considered circular Taylor-Couette flow and measured the flow near the mid-gap. Referring to figures \[fig:upsikep\] and \[fig:meanflow\] one sees that the mid-plane ($y=0$) is not the ideal plane on which to obverve the mean flow since its structure is most pronounced between the midplane and the upper or lower walls.
Before considering the symmetries and force balances in detail, it is instructive to consider the dominant force balance just at the centre of the laminar region. Recall that one of the more interesting features of the mean flow is that the $U$ profile appears very similar to a turbulent profile, even in the absence of turbulence in the laminar region. Here the balance is dominated by advection and viscous diffusion, as shown in figure \[fig:forcepreface\]. Equation for flow in the $x$-direction is $$0 = -\left(V {\ensuremath{\partial}}_y + (W + \beta y) {\ensuremath{\partial}}_z \right) (U + \alpha y)
+ {\frac{1}{{\mbox{\textit{Re}}}}}({\ensuremath{\partial}}^2_y + {\ensuremath{\partial}}^2_z) U + {F}^U.$$
Variations in $y$ dominate variations in $z$, [i.e.]{} the usual boundary-layer approximation $({\ensuremath{\partial}}^2_y + {\ensuremath{\partial}}^2_z) U \simeq {\ensuremath{\partial}}^2_y U$ holds; see, [e.g.]{} [@Pope]. Indeed, approximating the $y$ dependence of $U$ by the functional form $\sin(\pi y)$ suggested by figure \[fig:meanflow\], we have $$O\left(\frac{{\ensuremath{\partial}}^2_y U}{{\ensuremath{\partial}}^2_z U}\right) =
\frac{\pi^2}{k^2} = \frac{\pi^2}{(2\pi/40)^2}=400
\label{eq:d2ytod2z}$$ This is confirmed by the second panel of figure \[fig:forcepreface\]. In the centre of the laminar region ${F}^U$, $V$, and $W$ are all negligible, so that $-\beta y {\ensuremath{\partial}}_z U$ dominates the advective terms, as shown in the third panel of figure \[fig:forcepreface\]. Thus the balance between advection and viscosity in the laminar region is $$\beta\: y \: {\ensuremath{\partial}}_z U \approx {\frac{1}{{\mbox{\textit{Re}}}}}{\ensuremath{\partial}}^2_y U.
\label{eq:firstapprox}$$
This equation is appealingly simple and yet leads immediately to some interesting conclusions. The first is that a non-zero tilt angle $\theta$ is necessary to maintain the S-shaped $U$ profile in the laminar region, since otherwise $\beta = \sin \theta = 0$ and $U$ could be at most linear in $y$ and would in fact be zero, due to the homogeneous boundary conditions (\[eq:homogbc\]). The second conclusion follows from consideration of $y$ parity. The multiplication by $y$ on the left-hand-side reverses $y$-parity, while the second derivative operator on the right-hand-side preserves $y$ parity. The conclusion is that $U$ should be decomposed into odd and even components in $y$ and equation should actually be understood as two equations coupling the two components. Specifically, as can be seen in figure \[fig:meanflow\], $U$ is odd in $y$ in the centre of the laminar region, yet ${\ensuremath{\partial}}_z U$ must be even for equation to hold.
The remainder of the paper is devoted to formalising, demonstrating and extending this basic idea.
![Balance of forces in the center of the laminar region. Left: Forces in the $U$ direction. Advective terms (blue, solid), viscous terms (red, dashed), Reynolds-stress terms (green, dotted). Middle: Viscous terms in the $U$ direction. $(1/Re)\,{\ensuremath{\partial}}^2_y U$ (red, dashed) dominates dominates $(1/Re)\,{\ensuremath{\partial}}^2_z U$ (green, dotted). Right: Advective terms in the $U$ direction. Curves show $-\beta\,y\,{\ensuremath{\partial}}_z U$ (blue, solid) $-W{\ensuremath{\partial}}_z U$ (black, dash-dot), $-\alpha V$ (green, dotted), $-V{\ensuremath{\partial}}_y U$ (red, dashed). Right-most: Advective terms in the $W$ direction (for later reference). Curves show $-\beta\, y\, {\ensuremath{\partial}}_z W$ (blue, solid) $-W{\ensuremath{\partial}}_z W$ (black, dash-dot), $-\beta V$ (green, dotted), $-V{\ensuremath{\partial}}_y W$ (red, dashed). []{data-label="fig:forcepreface"}](Figures/forcepreface.ps){width="13cm"}
[ ]{}
Symmetry and Fourier modes {#sec:Symmetry}
--------------------------
We now consider in depth the symmetry properties of the flow. We start with the symmetries of the system before averaging, that is, the Navier-Stokes equations and boundary conditions . The system has translation symmetry in $x$ and $z$ as well as centrosymmetry under combined reflection in $x$, $y$ and $z$: $${\kappa_{xyz}}(u,v,w)(x,y,z) \equiv (-u,-v,-w)(x_0-x,-y,z_0-z)
\label{eq:Cfdef}$$ where the origin $x_0$, $z_0$ can be chosen arbitrarily. Linear Couette flow ${{\bf u}}^L$ possesses all the system symmetries, as does the mean flow at Reynolds numbers for which turbulence is statistically homogeneous in $x$ and $z$.
Note that in the absence of tilt ($\theta=0$), the system possesses two reflection symmetries. These can be taken to be ${\kappa_{xyz}}$ and reflection in the spanwise direction. For the tilted domain (at angles other than multiples of $90^\circ$), the only reflection symmetry is ${\kappa_{xyz}}$. This can be seen in figure \[fig:domains\](a): for general tilt angles $\theta$, spanwise reflection does not preserve the domain, [i.e.]{} does not leave the periodic boundaries in place. The experimental system shown in figure \[fig:experiment\] possesses spanwise reflection symmetry and hence bands can be observed in the either of the two symmetrically related angles, the choice is dictated by factor such as initial conditions. By design, our tiled computational domain precludes the symmetry-related pattern given by spanwise reflection.
The transition to the turbulent-laminar patterned state breaks symmetry. Specifically, both the mean flow and the Reynolds-stress force break $z$-translation symmetry but break neither $x$-translation symmetry nor centrosymmetry. The spatial phase of the pattern in $z$ is arbitrary, but given a phase there are two values of $z_0$, separated by half a period, for which the flow is invariant under ${\kappa_{xyz}}$, as is typical for a circle pitchfork bifurcation [-@Crawford]. As can be seen in figure \[fig:upsikep\], the values of $z_0$ about which the patterns are centrosymmetric are the centres of the laminar ($z_0=0$) and of the turbulent ($z_0=\pm 20$) regions.
The centrosymmetry operator for our averaged fields ${{\bf U}}$, which depend only on $y$ and $z$, is $${\kappa_{yz}}(U,V,W)(y,z) \equiv (-U,-V,-W)(-y,z_0-z)
\label{eq:Cdef}$$ Since the Reynolds-stress force $({F}^U, {F}^V, {F}^W)$ is centrosymmetric in the case we consider, then the averaged equations for the mean field have centrosymmetry.
We formalise this further as follows. Any $x$-independent field ${{\bf g}}$ can be decomposed into even and odd functions of $y$ and $z$ as $${{\bf g}}(y,z)={{\bf g}}_{oo}(y,z) + {{\bf g}}_{oe}(y,z) + {{\bf g}}_{eo}(y,z) + {{\bf g}}_{ee}(y,z)
\label{eq:4fcns}$$ where, for example, ${{\bf g}}_{oe}$ is odd in $y$ and even in $z-z_0$. Applying the operator in (\[eq:Cdef\]) to (\[eq:4fcns\]), we obtain $$\begin{aligned}
{\kappa_{yz}}{{\bf g}}(y,z)
&=&-{{\bf g}}_{oo}(-y,z_0-z) - {{\bf g}}_{oe}(-y,z_0-z)
- {{\bf g}}_{eo}(-y,z_0-z) - {{\bf g}}_{ee}(-y,z_0-z)
\nonumber\\
&=&-{{\bf g}}_{oo}(y,z) + {{\bf g}}_{oe}(y,z) + {{\bf g}}_{eo}(y,z) - {{\bf g}}_{ee}(y,z)\end{aligned}$$ For the field ${{\bf g}}$ to be centrosymmetric requires ${\kappa_{yz}}{{\bf g}}= {{\bf g}}$, so that in fact $${{\bf g}}(y,z)={{\bf g}}_{oe}(y,z) + {{\bf g}}_{eo}(y,z)
\label{eq:2fcns}$$ Table \[tab:symmetry\], as well as figure \[fig:upsikep\], shows that this is indeed the case for ${{\bf U}}$; it holds for ${\bf F}$ as well.
[ ]{}
$$\begin{aligned}
\begin{array}{c||c|c|}
& {\mbox{$z$ even}} & {\mbox{$z$ odd}} \\
\cline{1-3}
{\mbox{$y$ even}} & {0.03\%} & {25.48\%} \\
\cline{1-3}
{\mbox{$y$ odd}} & {74.48\%} & {0.01\%} \\
\cline{1-3}
\end{array}
\nonumber\end{aligned}$$
$$\begin{aligned}
\begin{array}{c||ccc|cc|}
& \multicolumn{3}{|c|} {\mbox{$z$ even (cosine)}} &
\multicolumn{2}{|c|} {\mbox{$z$ odd (sine)}}\\
\mbox{$z$ wavenumber}& 0 & k & \geq 2k & k & \geq 2k \\ \cline{1-6}
\mbox{$y$ even} &&&&\fbox{25.2\%} & {0.3\%} \\ \cline{1-6}
\mbox{$y$ odd} & \fbox{69.7\%} & \fbox{4.7\%} & 0.1\% & & \\ \cline{1-6}
\end{array}
\nonumber\end{aligned}$$
We now Fourier transform in $z$ to further decompose the mean velocity and the Reynolds-stress force. We find that the $z$-wavenumbers $0$ and $\pm k$ have contributions to ${{\bf U}}$ which are an order of magnitude higher than the remaining wavenumber combinations. See table \[tab:fourier\]. The deviation from the $z$ average is thus almost exactly trigonometric, with almost no higher harmonic content. The dominance of these terms in the Fourier series means that ${{\bf U}}$ and ${\bf F}$ can be represented by only three functions of $y$, namely: $${{\bf g}}(x,y,z)={{\bf g}}_0(y) + {{\bf g}}_c(y) \cos(kz) + {{\bf g}}_s(y) \sin(kz)
\label{eq:3fcns}$$ which is a special case of , with the first two terms of coinciding with ${{\bf g}}_{oe}(y,z)$ and the last to ${{\bf g}}_{eo}$. Thus, ${{\bf g}}_0$ and ${{\bf g}}_c$ are odd functions of $y$, while ${{\bf g}}_s$ is even. The fields thus consist of a $z$-independent component ${{\bf g}}_0$ and two components which vary trigonometrically and out of phase with one another, ${{\bf g}}_c$ dominating in the laminar and turbulent regions and ${{\bf g}}_s$ dominating in the boundaries between them. Moreover, ${{\bf g}}_s$ dominates in the bulk, since ${{\bf g}}_0$ and ${{\bf g}}_c$ are odd in $y$ and thus zero in the channel centre.
\[eq:trigexpand\] $$\begin{aligned}
&{{\bf g}}={{\bf g}}_0(y)+{{\bf g}}_c(y) && z=0:&
\mbox{Centre of laminar region} \label{eq:g0}\\
&{{\bf g}}={{\bf g}}_0(y)+{{\bf g}}_s(y) && z=\lambda_z/4=10:&
\mbox{Laminar-turbulent boundary} \label{eq:g10}\\
&{{\bf g}}={{\bf g}}_0(y)-{{\bf g}}_c(y) && z=\lambda_z/2=20:&
\mbox{Centre of turbulent region} \label{eq:g20}\\
&{{\bf g}}={{\bf g}}_0(y)-{{\bf g}}_s(y) && z=3\lambda_z/4=30:&
\mbox{Turbulent-laminar boundary} \label{eq:g30}\end{aligned}$$
Figure \[fig:fourmean\] shows the three trigonometric components, each a function of $y$, obtained by Fourier transforming $U$, $V$, and $W$. Figure \[fig:profileZuvw\] shows $U$, $V$ and $W$ as functions of $z$ at locations in the upper and lower channel and compares them with the values obtained from the trigonometric formula using the functions shown in figure \[fig:fourmean\]. Figures \[fig:udecomp\], \[fig:psidecomp\] and \[fig:Reyudecomp\] depict $U(y,z)$, $\Psi(y,z)$ and ${F}^U(y,z)$ with their trigonometric decompositions. Each of these figures uses only the three scalar functions of $y$, figure \[fig:fourmean\], to reproduce the corresponding two-dimensional field. As shown by equation , the streamfunction $\Psi$ of a centrosymmetric field has symmetry opposite to that of the velocity components, [i.e.]{} it is composed of functions of the same parity in $y$ and $z$.
![Fourier decomposition of mean velocity. $U$ component (blue, solid), $V$ component (green, dotted), $W$ component (red, dashed). $W_c \approx
-W_0$, corresponding to the fact that $W$ shows no deviation from the linear in the laminar region. []{data-label="fig:fourmean"}](Figures/fourmean.ps){width="14cm"}
![Mean flow as a function of $z$ at $y=0.725$ (lower curves) and $y=-0.725$ (upper curves). $U$ (blue, solid), $V$ (green, dotted), $W$ (red, dashed). Dots show values calculated from trigonometric formula .[]{data-label="fig:profileZuvw"}](Figures/profileZuvw.ps){width="8cm"}
![Reynolds-stress force ${F}^U$ and its trigonometric decomposition. Color scale is ${F}^U~(-0.017,0.017)$, ${F}^U_0 (-0.0085,0.0085)$, ${F}^U_c (-0.0085,0.0085)$, ${F}^U_s (-0.0085,0.0085)$.[]{data-label="fig:Reyudecomp"}](Figures/udecompmake.ps){width="14cm"}
![Reynolds-stress force ${F}^U$ and its trigonometric decomposition. Color scale is ${F}^U~(-0.017,0.017)$, ${F}^U_0 (-0.0085,0.0085)$, ${F}^U_c (-0.0085,0.0085)$, ${F}^U_s (-0.0085,0.0085)$.[]{data-label="fig:Reyudecomp"}](Figures/psidecompmake.ps){width="14cm"}
![Reynolds-stress force ${F}^U$ and its trigonometric decomposition. Color scale is ${F}^U~(-0.017,0.017)$, ${F}^U_0 (-0.0085,0.0085)$, ${F}^U_c (-0.0085,0.0085)$, ${F}^U_s (-0.0085,0.0085)$.[]{data-label="fig:Reyudecomp"}](Figures/Reyudecompmake.ps){width="14cm"}
Figures \[fig:Reynolds\] and \[fig:fourrey\] show the three Reynolds-stress forces and their Fourier decompositions. Each component obeys ${\bf F}_c\approx-{\bf F}_0$, a necessary condition for ${\bf F}$ to vanish at the centre of the laminar region, as shown by equation and also illustrated in figure \[fig:Reyudecomp\]. More precisely, $${F}^U_c = -1.09 {F}^U_0, ~~~~~ {F}^V_c = -1.22 {F}^V_0, ~~~~~ {F}^W_c = -1.16 {F}^W_0
\label{eq:falmostzero}$$ In addition, $${\bf F}\approx -{\ensuremath{\partial}}_y {\langle}{\tilde{{{\bf u}}}}{\tilde{v}}{\rangle}.$$ as is typical for turbulent channel flows; see, [e.g.]{} [@Pope]. [ ]{}
![Reynolds-stress force ${\bf F}=-{\langle}({\tilde{{{\bf u}}}}\cdot\nabla){\tilde{{{\bf u}}}}{\rangle}$ as a function of $y$. Curves show ${F}^U$ (blue, solid), ${F}^V$ (green, dotted) and ${F}^W$ (red, dashed).[]{data-label="fig:Reynolds"}](Figures/Reynolds.ps){width="14cm"}
![Fourier decomposition of Reynolds-stress force. ${F}^U$ components (blue, solid), ${F}^V$ components (green, dotted), ${F}^W$ components (red, dashed). ${\bf F}_c\approx-{\bf F}_0$, as required for the vanishing of ${\bf F}$ at $z=0$.[]{data-label="fig:fourrey"}](Figures/fourrey.ps){width="14cm"}
Force balance for $U$ {#sec:ForceU}
---------------------
We now turn to understanding the balance of forces responsible for maintaining the mean flow profiles. We focus primarily on $U$, both because it is the component of largest amplitude and also because it appears only in equation : $U$ is subject to Reynolds-stress and viscous forces, and is advected by $(V,W)$ but is not self-advected. We begin by showing the balance of forces in the $U$ direction as a function of $z$ at locations in the upper and lower channel in figure \[fig:balance\]. One can again see the centrosymmetry of each of the forces, [i.e.]{} invariance under the combined operations of reflection in $y$ and $z$ and change of sign. The Reynolds-stress force disappears at the center of the laminar region and the advective and viscous forces exactly counterbalance, as emphasized in the figures on the right. Figure \[fig:Forceu\] shows another view of this balance, displaying the forces as a function of $y$ at four locations in $z$. As previously stated, ${\nabla^2}U$ is dominated by ${\ensuremath{\partial}}^2_y U$ and ${F}^U$ by $-{\ensuremath{\partial}}_y {\langle}{\tilde{u}}{\tilde{v}}{\rangle}$. In figure \[fig:FourForceu\], we show the Fourier-space analogue of figure \[fig:Forceu\].
![Mean forces in $U$ direction as a function of $z$ at $y=\pm 0.725$ for turbulent-laminar pattern at $Re=350$. Advective $-({{\bf U}}\cdot\nabla) U$ (blue, solid), viscous ${\nabla^2}U$ (red, dashed), and turbulent $-{\langle}({\tilde{{{\bf u}}}}\cdot\nabla) {\tilde{u}}{\rangle}$ (green, dotted) forces. In the laminar region ($z\approx 0$), the Reynolds-stress force vanishes and the viscous and advective forces are equal and opposite to one another. In figures on right, enlarged around the laminar region, ${\nabla^2}U$ and $+({{\bf U}}\cdot\nabla) U$ are shown to emphasize equality between viscous and advective forces.[]{data-label="fig:balance"}](Figures/newbalance.ps){width="17cm"}
![Advective terms in the $U$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z U$ (black, solid) $-W{\ensuremath{\partial}}_z U$ (blue, dash-dot), $-\alpha V$ (green, dotted), $-V{\ensuremath{\partial}}_y U$ (red, dashed). The 1 mode is generated by the product $-k W_c U_s/2$; a second harmonic of the same small size is also generated. The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,U_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,U_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (U_0+\alpha y)$ in the bulk.[]{data-label="fig:FourNonu"}](Figures/Forceu.ps){width="14cm"}
![Advective terms in the $U$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z U$ (black, solid) $-W{\ensuremath{\partial}}_z U$ (blue, dash-dot), $-\alpha V$ (green, dotted), $-V{\ensuremath{\partial}}_y U$ (red, dashed). The 1 mode is generated by the product $-k W_c U_s/2$; a second harmonic of the same small size is also generated. The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,U_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,U_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (U_0+\alpha y)$ in the bulk.[]{data-label="fig:FourNonu"}](Figures/fourtotu.ps){width="14cm"}
![Advective terms in the $U$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z U$ (black, solid) $-W{\ensuremath{\partial}}_z U$ (blue, dash-dot), $-\alpha V$ (green, dotted), $-V{\ensuremath{\partial}}_y U$ (red, dashed). The 1 mode is generated by the product $-k W_c U_s/2$; a second harmonic of the same small size is also generated. The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,U_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,U_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (U_0+\alpha y)$ in the bulk.[]{data-label="fig:FourNonu"}](Figures/fournonudetail.ps){width="14cm"}
We now turn to the more complex advective forces, whose Fourier decompositions are shown in figure \[fig:FourNonu\]. The $\cos(0z)$ component of the advective force is small but non-zero. Because this term results from the product of trigonometric functions, it also provides a measure of the generation of higher harmonics, a point which we will explore further in section \[sec:Model\]. The advective $\cos(kz)$ term is well approximated by the contribution from advection by $w^L=\beta y$. The advective $\sin(kz)$ term is dominated near the walls by advection by $w^L$, but in the bulk by advection by $V$. Properties of the $\cos(kz)$ and $\sin(kz)$ modes echo their physical space counterparts: the advective term is well approximated by advection by $w^L$ in the laminar region, as was shown in figure \[fig:forcepreface\], while the advective forces in the laminar-turbulent boundaries combine advection by $w^L$ near the walls and by $V$ in the bulk.
We illustrate these conclusions via schematic visualizations of the dynamics of $U$. Figure \[fig:schematic\_cos\] illustrates the dynamics in the laminar and turbulent regions. The dynamics in the laminar region are essentially described by the simple balance between viscous diffusion of $U$ profiles and advection by linear Couette flow in $z$, given by equation . Viscous diffusion tends to reduce curvature, but the profiles have greater curvature upstream (to the left for the upper channel, to the right for the lower channel). Hence advection replenishes the curvature damped by viscosity. However, this trend towards greater curvature upstream cannot continue indefinitely, since the pattern is periodic in $z$. Hence eventually a maximum is reached (at a turbulent-laminar boundary), beyond which the curvature decreases upstream. Thus, in the turbulent region, advection and diffusion act together to decrease curvature and must both be counter-balanced by turbulent forcing. These features are essentially described by the $\cos(0z)=1$ and $\cos(kz)$ modes. Figure \[fig:schematic\_sin\] illustrates the dynamics in the turbulent-laminar boundaries. These dynamics include advection by $V$ in the bulk, leading to the $U>0$ ($U<0$) patch in the lower right (upper left) of figure \[fig:udecomp\] and are described by the $\sin(kz)$ mode. [ ]{}
![Schematic depiction of the dynamics of $U$ near the centres of the laminar and of the turbulent regions. The cross-channel direction is exaggerated. Shown are $U$ (profiles) and $W+\beta y$ (arrows). Viscous diffusion tends to diminish both peaks of the profile. In laminar region surrounding $z=0$, the peaks in the upper half-channel increase in amplitude with decreasing $z$; advection towards positive $z$ (upper arrow) replenishes these peaks, maintaining $U$. Conversely, the peaks in the lower half-channel increase with $z$; advection towards negative $z$ (lower arrow) replenishes these peaks. That is, the sign of $-(W+\beta y)\,{\ensuremath{\partial}}_z U$ is opposite to that of ${\ensuremath{\partial}}^2_y U$ in both the upper and lower parts of the laminar region. In the turbulent region around $z=\pm 20$, the size of the upper (lower) peak decreases to the left (right) and so advection, like viscous diffusion, acts instead to diminish the peaks. $U$ is maintained by the Reynolds-stress force, which counterbalances both. The effect is to modulate the amplitude of the $U$ profiles periodically in $z$.[]{data-label="fig:schematic_cos"}](Figures/schematic_cos.ps){width="13cm"}
![Schematic depiction of the dynamics of $U$ near the turbulent-laminar boundaries. The cross-channel direction is exaggerated. Shown are $U+\alpha
y$ (profiles), and $(V, W+\beta y)$ (arrows). Near the upper and lower walls, the $U+\alpha y$ profiles are advected towards increasing/decreasing $z$ by $W + \beta y$. In the bulk, advection by $V$ is significant. At $z\approx 10$, $V$ advects downwards the right-moving fluid in the upper portion of the channel. At $z\approx -10$, $V$ advects upwards the left-moving fluid in the lower portion of the channel. The effect is to tilt the $U=0$ boundary periodically in $z$.[]{data-label="fig:schematic_sin"}](Figures/schematic_sin.ps){width="13cm"}
Force balance for $W$ and $V$ {#sec:ForceWV}
-----------------------------
![Advective terms in the $W$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z W$ (black, solid) $-W{\ensuremath{\partial}}_z W$ (blue, dash-dot), $-\beta V$ (green, dotted), $-V{\ensuremath{\partial}}_y W$ (red, dashed). The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,W_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,W_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (W_0+\beta y)$ in the bulk.[]{data-label="fig:FourNonw"}](Figures/Forcew.ps){width="14cm"}
[ ]{}
![Advective terms in the $W$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z W$ (black, solid) $-W{\ensuremath{\partial}}_z W$ (blue, dash-dot), $-\beta V$ (green, dotted), $-V{\ensuremath{\partial}}_y W$ (red, dashed). The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,W_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,W_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (W_0+\beta y)$ in the bulk.[]{data-label="fig:FourNonw"}](Figures/fourtotw.ps){width="14cm"}
![Advective terms in the $W$ direction, decomposed into modes. Curves show $-\beta y {\ensuremath{\partial}}_z W$ (black, solid) $-W{\ensuremath{\partial}}_z W$ (blue, dash-dot), $-\beta V$ (green, dotted), $-V{\ensuremath{\partial}}_y W$ (red, dashed). The $\cos(kz)$ mode is dominated by $-\beta\,y\,k\,W_s$. The $\sin(kz)$ term is dominated by $\beta\,y\,k\,W_c$ near the boundaries and by $-V_s{\ensuremath{\partial}}_y (W_0+\beta y)$ in the bulk.[]{data-label="fig:FourNonw"}](Figures/fournonwdetail.ps){width="14cm"}
Figure \[fig:Forcew\] shows the balance of forces in the $W$ direction and figure \[fig:FourForcew\] its analogue in Fourier space. This balance resembles that in the $U$ direction shown in figures \[fig:Forceu\] and \[fig:FourForceu\]. In physical space (compare the leftmost panels of figures \[fig:Forcew\] and \[fig:Forceu\]), the main difference is that the advective and viscous forces are both small in the laminar region, in keeping with the fact that $W\approx 0$. The pressure gradient ${\ensuremath{\partial}}_z P$ is far smaller than the other forces throughout (see below). In Fourier space (compare the middle panels of figures \[fig:FourForcew\] and \[fig:FourForceu\]), the main difference with the $U$ balance is that the relative importance of the viscous and advective forces in the $\cos(kz)$ balance is reversed from that in the case of $U$: for $W$, the viscous component is larger than the advective component, which is especially small in the bulk. The decomposition of the advective terms (figure \[fig:FourNonw\]) shows that, as is the case for $U$, the advective $\cos(kz)$ term is well approximated by the contribution from advection by $w^L=\beta y$, whereas all four advective components contribute to the $\sin(kz)$ term.
The balance of forces in the $V$ direction is entirely different. The dominant balance in this equation is: $$0 = -{\ensuremath{\partial}}_y P + {F}^V
\label{eq:Vdombal}$$ as shown in figure \[fig:forcev\]. This is typical for turbulent channel flows; see, [e.g.]{} [@Pope]. This balance between the mean pressure gradient $P$ and the Reynolds-stress force ${F}^V$ does not constrain or provide information about any of the velocity components. Since $${F}^V=-{{\boldsymbol{\nabla}}\cdot}{\langle}{\tilde{{{\bf u}}}}{\tilde{v}}{\rangle}\approx -{\ensuremath{\partial}}_y{\langle}{\tilde{v}}^2{\rangle}$$ [ ]{} we in fact have $$P\approx-{\langle}{\tilde{v}}^2{\rangle}\label{eq:v2fluc}$$ up to a small $z$-dependent correction. Figure \[fig:upsikep\] shows the pressure field $P$ calculated from and suggests that its $y$ dependence can be approximated by the functional form $\cos(\pi y/2)$. This leads to an estimate of the relative importance of the pressure gradients in the $y$ and $z$ directions: $$O\left(\frac{{\ensuremath{\partial}}_y P}{{\ensuremath{\partial}}_z P}\right)= \frac{\pi/2}{k} \approx 10
\label{eq:dyPtodzP}$$ while our data shows $$\frac{({\ensuremath{\partial}}_y P)_{\rm max}}{({\ensuremath{\partial}}_z P)_{\rm max}} = \frac{0.012}{0.0017} = 7.05$$ The same estimate applies to the relative magnitudes of $V$ and $W$, using the streamfunction shown in figure \[fig:upsikep\]: $$O\left(\frac{W}{V}\right) =
O\left(\frac{{\ensuremath{\partial}}_y \Psi}{{\ensuremath{\partial}}_z \Psi}\right) = \frac{\pi/2}{2\pi/40} = 10
\label{eq:WtoV}$$ while the actual ratio of maximum values is $$\frac{W_{\rm max}}{V_{\rm max}} = \frac{0.15}{0.013} = 11.$$
[ ]{}
![Forces in the $V$ direction. Reynolds-stress force ${F}^V$(red, dashed) is counterbalanced by pressure gradient $-{\ensuremath{\partial}}_y P$ (blue, solid). Both are zero in the laminar region. Advective and viscous forces (green, dotted) are negligible throughout.[]{data-label="fig:forcev"}](Figures/Forcev.ps){width="14cm"}
Model equations {#sec:Model}
---------------
We now derive a system of ordinary differential equations by substituting the trigonometric form into the Reynolds-averaged Navier-Stokes equations . The drawback in this procedure is the usual one, namely that this form is not preserved by multiplication. However, Table \[tab:fourier\] shows that higher harmonics contribute very little to ${{\bf U}}$.
We expand the advective term as:
\[eq:nonnon\] $$\begin{aligned}
(({{\bf U}}+{{\bf u}}^L)\cdot{{\boldsymbol{\nabla}}})&&({{\bf U}}+{{\bf u}}^L)
= (V\:{\ensuremath{\partial}}_y + (W+\beta y)\:{\ensuremath{\partial}}_z) ({{\bf U}}+\alpha y {{\bf e_x}}+\beta y {{\bf e_z}})\nonumber\\
&=& (V_c\cos(kz)+V_s\sin(kz))
({{\bf U}}{^\prime}_0+{{\bf U}}{^\prime}_c\cos(kz) + {{\bf U}}{^\prime}_s\sin(kz) +\alpha {{\bf e_x}}+\beta {{\bf e_z}})\nonumber\\
&+&(W_0+\beta y +W_c\cos(kz)+W_s\sin(kz))
(-k\:{{\bf U}}_c\sin(kz)+k\:{{\bf U}}_s\cos(kz))\nonumber\\
&=&{\frac{1}{2}}\left(V_c\:{{\bf U}}{^\prime}_c+V_s\:{{\bf U}}{^\prime}_s+k\:(W_c\:{{\bf U}}_s-W_s\:{{\bf U}}_c)\right)
\label{eq:non0}\\
&+&(V_c ({{\bf U}}{^\prime}_0+\alpha{{\bf e_x}}+\beta{{\bf e_z}}) +k\:(W_0+\beta y){{\bf U}}_s)\cos(kz)
\label{eq:nonc1}\\
&+&(V_s ({{\bf U}}{^\prime}_0 +\alpha{{\bf e_x}}+ \beta{{\bf e_z}}) -k\:(W_0+\beta y){{\bf U}}_c)\sin(kz)
\label{eq:nons1}\\
&+&{\frac{1}{2}}\left(V_c\:{{\bf U}}{^\prime}_c-V_s\:{{\bf U}}{^\prime}_s+k\:(W_c\:{{\bf U}}_s+W_s\:{{\bf U}}_c)\right)
\cos(2kz),\label{eq:non2}\end{aligned}$$
where primes denote $y$ differentiation. We neglect the second harmonic term , and will discuss the accuracy of this approximation below. We now rewrite the $U$ and $W$ components of the averaged momentum equations, neglecting the $z$-derivatives ${\ensuremath{\partial}}^2_z U$, ${\ensuremath{\partial}}^2_z W$ and ${\ensuremath{\partial}}_z P$, as justified by equations and :
\[eq:RANSnew\] $$\begin{aligned}
0 &=& -\left(V {\ensuremath{\partial}}_y + (W + \beta y)~ {\ensuremath{\partial}}_z \right) (U + \alpha y)
+ {\frac{1}{{\mbox{\textit{Re}}}}}{\ensuremath{\partial}}^2_y U + {F}^U \\
0 &=& -\left(V {\ensuremath{\partial}}_y + (W + \beta y)~ {\ensuremath{\partial}}_z \right) (W + \beta y)
+ {\frac{1}{{\mbox{\textit{Re}}}}}{\ensuremath{\partial}}^2_y W + {F}^W \end{aligned}$$
Substituting – in and separating terms in $\cos(0z)=1$, $\cos(kz)$ and $\sin(kz)$, we obtain
$$\begin{aligned}
0 &=& -{\frac{1}{2}}\left[V_c U{^\prime}_c + V_s U{^\prime}_s + k(W_c U_s - W_s U_c) \right]
+{\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_0 + {F}^U_0 \label{eq:u0}\\
0 &=& -V_c (U{^\prime}_0+\alpha) - k\:(W_0+\beta y) U_s +
{\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_c + {F}^U_c \label{eq:uc}\\
0 &=& -V_s (U{^\prime}_0+\alpha) + k\:(W_0 +\beta y) U_c +
{\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_s + {F}^U_s \label{eq:us}\\
0 &=& -{\frac{1}{2}}\left[V_c W{^\prime}_c+ V_s W{^\prime}_s \right]
+{\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_0 + {F}^W_0 \label{eq:w0}\\
0 &=& -V_c (W{^\prime}_0+\beta) - k\:(W_0+\beta y) W_s +
{\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_c + {F}^W_c \label{eq:wc}\\
0 &=& -V_s (W{^\prime}_0+\beta) +k\:(W_0 +\beta y) W_c +
{\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_s + {F}^W_s \label{eq:ws}\end{aligned}$$
\[eq:UWeqs\]
where the Fourier modes of $V$ and $W$ are related via those of the streamfunction $\Psi$ of :
\[eq:Psicomps\] $$\begin{aligned}
&V_0 = 0 & W_0 = \Psi{^\prime}_0 \\
&V_c = -k\Psi_s & W_c = \Psi{^\prime}_c \\
&V_s = k\Psi_c & W_s = \Psi{^\prime}_s\end{aligned}$$
and where homogeneous boundary conditions are imposed:
0&=& U\_0 = U\_c = U\_s y=1\
0&=& W\_0 = W\_c = W\_s y=1 \[eq:UWbcs\]
[ ]{}
System with boundary conditions is composed of six ordinary differential equations coupling the six scalar functions $U_0,U_c,U_s,\Psi_0,\Psi_c,\Psi_s$ of $y$, with six turbulent forces ${F}^U_0,{F}^U_c,{F}^U_s,{F}^W_0,{F}^W_c,{F}^W_s$.
We have solved – numerically, using as inputs ${F}^U$ and ${F}^W$ obtained from our full simulations, [i.e.]{} the ${\bf F}$ modes shown in figure \[fig:fourrey\]. The resulting solutions are shown in figure \[fig:fourdb\]. For comparison, we reproduce from figure \[fig:fourmean\] the mean velocity fields, in Fourier representation, from our full simulations (DNS). The ODE solutions are virtually indistinguishable from the mean fields from DNS. Only in the sine component of $U$ can the ODE solutions be distiguished (and only very slightly) from the DNS results. From the profiles in figure \[fig:fourdb\], the full mean fields could be constructed as in figures \[fig:udecomp\] and \[fig:psidecomp\]. Thus, while the ODE model requires input of the Reynolds-stress force terms, ${F}^U$ and ${F}^W$, it demonstrates the simplicity of the force balance responsible for generating the patterned flow when viewed in the Fourier representation. Considering higher harmonics would be straightforward, but would serve little purpose.
![Comparison between mean velocities (in Fourier representation) from full DNS and ODE models. Top row: Curves show $U$ (blue, solid) and $W$ (red, dashed) from DNS. Dots show solution to the full ODE model , essentially indistinguishable from the solid curves. Bottom row: Curves again show $U$ (blue, solid) and $W$ (red, dashed) from DNS. Dots show solution to simplified ODE model . The agreement with DNS is very good, though there are small differences particularly in the $U$ component.[]{data-label="fig:fourdb"}](Figures/modeldb.ps){width="14cm"}
We can go in the other direction and attempt to simplify system . The approximate equalities ${F}^U_c\approx -{F}^U_0$, ${F}^W_c\approx -{F}^W_0$ \[see equation \], necessary for ${\bf F}$ to vanish at the center of the laminar region, can be imposed exactly, reducing the number of turbulent forcing input functions to four. The terms arising from the advective forces can be reduced by making approximations justified from figures \[fig:FourNonu\] and \[fig:FourNonw\]. The nonlinear terms in and can be neglected. The advective terms in and can be approximated by $-k\,\beta \,y \,U_s$ and $-k\,\beta\, y \,W_s$. Making these approximations, we obtain:
$$\begin{aligned}
0 &=& {\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_0 + {F}^U_0 \label{eq:u0simp}\\
0 &=& - k \,\beta \,y \,U_s + {\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_c - {F}^U_0 \label{eq:ucsimp}\\
0 &=& - V_s (U{^\prime}_0+\alpha) + k (W_0+\beta y) U_c
+ {\frac{1}{{\mbox{\textit{Re}}}}}U{^{\prime\prime}}_s +{F}^U_s \label{eq:ussimp}\\
0 &=& {\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_0 + {F}^W_0\label{eq:w0simp}\\
0 &=& - k \,\beta \,y \,W_s + {\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_c - {F}^W_0\label{eq:wcsimp}\\
0 &=& -V_s (W{^\prime}_0 +\beta) + k (W_0+\beta y) W_c
+ {\frac{1}{{\mbox{\textit{Re}}}}}W{^{\prime\prime}}_s + {F}^W_s \label{eq:wssimp}\end{aligned}$$
\[eq:UWeqssimp\]
The solutions to this simplified ODE model are also presented in figure \[fig:fourdb\]. There is quite good agreement with full DNS results, thus demonstrating that the dominant force balance is captured by this very simple system of ODEs. We stress that the only nonlinearities in this model are in equations and . This reflects the complexity of the dynamics in the turbulent-laminar boundaries regions (and the simplicity of the dynamics in the centre of the turbulent and laminar regions.)
From the simplified ODE model we can obtain the approximate equation satisfied at the centre of the laminar region by adding equations (\[eq:u0simp\]) and (\[eq:ucsimp\]): $$k\,\beta\, y \, U_s= {\frac{1}{{\mbox{\textit{Re}}}}}(U_0+U_c){^{\prime\prime}}.
\label{eq:lam}$$ This is a restatement in terms of Fourier components of the balance described by equation and figure \[fig:forcepreface\].
Discussion
==========
We have presented an analysis of a particular turbulent-laminar pattern obtained in simulations of large-aspect-ratio plane Couette flow. We have focused on a single example so as to understand in quantitative detail the structure of these unusual flows. The key findings obtained in our study are as follows. First we find that in the (quasi-) laminar flow region the velocity profiles are not simply those of linear Couette flow. Instead a non-trivial flow is maintained in the laminar regions by a balance between viscous diffusion and nonlinear advection. Next we have considered the symmetries of the flow. When the pattern forms, the time-averaged flow breaks the translation symmetry but not centrosymmetry. The patterned state is centrosymmetric about the centre of the laminar region and about the center of the turbulent region. Next we have considered a spatial Fourier decomposition of the mean flow in the direction of the pattern wavevector. From this we find that the lateral structure of the pattern is almost completely harmonic, [i.e.]{} composed of a constant and single harmonic. Thus the pattern description can be reduced to just three cross-channel functions for each field, in that ${{\bf U}}(x,y,z) \approx {{\bf U}}_0(y) + {{\bf U}}_c(y) \cos(kz) + {{\bf U}}_s(y)\sin(kz)$. The absence of higher harmonics suggests that the pattern is near the threshold, in some sense, of a linear instability of a uniform turbulent state. Such an instability would be governed by a linear equation with coefficients which are constant in $z$, whose solutions are necessarily trigonometric in $z$.
From our analysis of the turbulent-laminar pattern, in particular its Fourier decomposition, we derive a model which reproduces the patterned flow. The model is derived from the averaged Navier-Stokes equations with the following assumptions. The crucial assumption, which is strongly supported by our numerical computations, is that the mean flow can be expressed in terms of just three horizontal modes. Effectively the generation of higher harmonics via nonlinear terms in the Navier-Stokes equations is negligible in the mean flow. The model is then further simplified because viscous diffusion is dominated by cross-channel diffusion – the standard boundary-layer approximation – and because pressure variation is negligible along the pattern wavevector. We take as input to the model the Reynolds-stress forces measured from computations. Assuming that the Reynolds stresses exactly vanish in the centre of the laminar regions, the number of inputs to the model is just four cross-channel functions. The result is a system of six simple ordinary differential equations which depend on four forcing functions. The model equations accurately reproduce the mean flow from full direct numerical simulations.
A number of other researchers have attempted to reduce the description of turbulent or transitional plane Couette flow by various means. At these low Reynolds numbers, there is no doubt that fully resolved direct numerical simulation is feasible and gives accurate results. The purpose of formulating a reduced description is therefore to yield understanding. We now comment on the differences between the approaches used by other authors and our reduction.
In parallel with their experiments, Prigent [[*et al.*]{}]{}([-@Prigent_PRL; -@Prigent_PhysD]) considered a pair of coupled Ginzburg-Landau (GL) equations with additive noise as a model for the transition from uniform turbulence to turbulent-laminar banded patterns via noisy (intermittent) patterns. These equations describe the variation in time and spanwise coordinate of the amplitudes $A^{\pm}$ of two sets of laminar bands at opposite tilt angles. These laminar bands modulate the uniform turbulence in competition with one another. Each equation separately has one reflection symmetry which corresponds physically to the centrosymmetry ${\kappa_{yz}}$ (equation ) of a banded pattern. The coupled GL equations possess a second reflection symmetry, corresponding physically to a spanwise reflection, which takes the amplitude $A^+$ to $A^-$ and vice versa. By design, this symmetry is not present in our numerical computations. Prigent [[*et al.*]{}]{} used their experimental results to fit the parameters in the GL equation and then compared simulations of the equations with experimental results. Steady patterns in the resulting GL equations have only one non-zero amplitude and this amplitude possesses the reflection symmetry corresponding to ${\kappa_{yz}}$. Hence, the steady patterns in these simulations have exactly the symmetries of the patterns we have considered.
An important class of models aims at reproducing dynamics of streamwise vortices and streaks in plane Couette turbulence by using a small number of ordinary differential equations (ODEs). These equations describe the time-evolution of amplitudes of modes with fixed spatial dependence. [@Waleffe_97], guided by the discovery of the self-sustaining process (SSP) in direct numerical simulations [@Hamilton], derived a system of eight ODEs, whose variables represent amplitudes of the key ingredients of the SSP, namely longitudinal vortices, streaks, and streak waviness. This model was later also studied and extended by [@Dauchot_Vioujard] and by [-@Moehlis_NJP].
Two other Galerkin projection procedures have been used to derive ODE models. The most energetic streamwise-independent modes in a principle orthogonal composition has been used as a basis for a 13-equation model [-@Moehlis_PF] exhibiting heteroclinic cycles; when streamwise-dependent modes are added, the resulting 31-equation model [-@Moehlis_JFM] reproduces elements of the SSP cycle. Eckhardt and co-workers [@Schmiegel; @Mersmann] have proposed a Fourier space truncation of the Navier-Stokes equations in all three spatial directions leading to a 19-equation model. They calculated turbulent lifetimes and saddle-node bifurcations giving rise to new steady states in this model.
Manneville and co-workers [@Manneville_Locher; @Lagha_Manneville] have proposed a drastic Galerkin truncation in the cross-channel direction $y$, retaining one or two trigonometric (for free-slip boundary conditions) or polynomial (for rigid boundary conditions) basis functions, but fully resolving both lateral directions. Simulating the resulting PDEs using a Fourier basis, they have been able to study phenomena such as the statistics of lifetimes of turbulent spots in domains with very large lateral dimensions.
The reduction we have presented differs from the aforementioned studies in several respects. Most importantly, we do not describe any time-dependent behaviour. We consider here neither turbulent-laminar patterns which are themselves dynamic (as in Prigent [[*et al.*]{}]{}), nor do we consider the dynamics of streaks and vortices within the turbulence, nor do we consider the transient dynamics of turbulence. Instead we focus on the spatially periodic mean flow of steady turbulent-laminar patterns. While the turbulent portions of patterns are dynamic, containing streaks and streamwise vortices, these are on a fine scale relative to spatial scales of interest here. Our model description follows directly from an analysis of full numerical simulations (not from any [*a priori*]{} assumptions, physical or phenomenological), that show that all averaged velocity components and forces, including the Reynolds stress force, are almost exactly trigonometric in the direction of the pattern wavevector. It follows directly that the steady Reynolds-averaged Navier-Stokes equations can be reduced to 6 ODEs for cross-channel profiles of the Fourier modes.
One of the more significant aspects of this work is the consideration of the force balance in just the laminar region. This balance is expressed by simple equations either in physical space, equation , or in Fourier space, equation . These equations are particularly interesting because they do not contain the Reynolds stresses, as these are negligable in the laminar region, and hence their implications can be understood without the need for closure assumptions.
As noted in §\[sec:meanflow\], equation implies that a non-zero tilt angle is necessary to maintain the S-shaped $U$ profile in the laminar region. If the patterns were not tilted, the flow would necessarily be laminar Couette flow in the centre of the laminar regions where the turbulence vanishes. We can also derive implications for the relationship between Reynolds number, tilt angle and wavelength of the patterns from equation , which we rewrite as: $$\frac{Re\,\sin\theta}{\lambda} = \frac{(U_0+U_c){^{\prime\prime}}}{2\pi \, y \, U_s}
\label{eq:firstapproxrewrite}$$ Except where $y\,U_s\approx 0$, the function on the right-hand-side is indeed approximately constant across the channel, between about 2.8 and 3.6. The value of $Re\,\sin\theta/\lambda$ used in our simulations is $350 \,\sin(24^\circ)/40=3.56$.
We may obtain a qualitative understanding of this constant as follows; see figure \[fig:Re\_beta\_lambda\] (left). Observe that in the center of the laminar region, the functional form of $U = U_0+U_c$ is like $\sin(\pi y)$. Hence its second $y$ derivative can be approximated by multiplication by $-\pi^2$, or equivalently $(U_0+U_c){^{\prime\prime}}/(-\pi^2) \approx U_0+U_c$. We also find that the odd function $-2 \,y \,U_s$ is close to $U_0+U_c$ and is in fact almost indistinguishable from $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$. This implies that the right-hand-side of equation is nearly constant across the channel and equal to $\pi$, leading to: $$\frac{{\mbox{\textit{Re}}}\, \sin\theta}{\lambda} \approx \pi
\label{eq:firstapprox2}$$
![Left: Comparison of profiles of $U_0+U_c$ (solid), $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ (dashed) and $-2\,y\,U_s$ (points). The profile of $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ is close to $U_0+U_c$, in accordance with the approximate functional form $(U_0+U_c)\sim \sin(\pi y)$. Note that $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ is almost indistinguishable from $-2\,y\,U_s$, showing that $(U_0+U_c){^{\prime\prime}}/(2\pi \, y \, U_s)$ is near $\pi$ over the entire channel. Right: Plot of ${\mbox{\textit{Re}}}\,\sin\theta/\lambda $ as a function of ${\mbox{\textit{Re}}}$ for the experimentally observed patterns of Prigent [[*et al.*]{}]{} ([-@Prigent_PhysD], [-@Prigent_IUTAM]). The open triangle shows ${\mbox{\textit{Re}}}\,\sin\theta/\lambda=3.56$ for the case studied numerically in this paper.[]{data-label="fig:Re_beta_lambda"}](Figures/wavelength.ps){width="5cm"}
![Left: Comparison of profiles of $U_0+U_c$ (solid), $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ (dashed) and $-2\,y\,U_s$ (points). The profile of $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ is close to $U_0+U_c$, in accordance with the approximate functional form $(U_0+U_c)\sim \sin(\pi y)$. Note that $(U_0+U_c){^{\prime\prime}}/(-\pi^2)$ is almost indistinguishable from $-2\,y\,U_s$, showing that $(U_0+U_c){^{\prime\prime}}/(2\pi \, y \, U_s)$ is near $\pi$ over the entire channel. Right: Plot of ${\mbox{\textit{Re}}}\,\sin\theta/\lambda $ as a function of ${\mbox{\textit{Re}}}$ for the experimentally observed patterns of Prigent [[*et al.*]{}]{} ([-@Prigent_PhysD], [-@Prigent_IUTAM]). The open triangle shows ${\mbox{\textit{Re}}}\,\sin\theta/\lambda=3.56$ for the case studied numerically in this paper.[]{data-label="fig:Re_beta_lambda"}](Figures/Re_beta_lambda.ps){width="6.2cm"}
We believe that equation provides a good first approximation for the relationship between ${\mbox{\textit{Re}}}$, $\lambda$, and $\theta$. Figure \[fig:Re\_beta\_lambda\] (right) shows a plot of ${\mbox{\textit{Re}}}\,
\sin\theta/\lambda$ as a function of ${\mbox{\textit{Re}}}$ from the experimental data of Prigent [[*et al.*]{}]{} ([-@Prigent_PhysD]). It can be seen that this combination of quantities is approximately constant with a value near $\pi$. The range of values of the individual factors ${\mbox{\textit{Re}}}$, $\theta$, and $\lambda$ can be seen in table \[tab:exp\_obs\]. In prior studies [@Barkley_PRL; @Barkley_IUTAM], we have studied a large range of Reynolds numbers and tilt angles in a domain of length $L_z=120$. In this domain, the wavelength of a periodic pattern is less constrained, though it must be a divisor of 120. Figure \[fig:angles\] shows the observed states as a function of ${\mbox{\textit{Re}}}$ and $\theta$. Equation captures the correct order of magnitude of ${\mbox{\textit{Re}}}\, \sin\theta/\lambda$; specifically $1.8 \lesssim {\mbox{\textit{Re}}}\, \sin\theta/\lambda \lesssim 5$. Moreover, in figure \[fig:angles\] one sees that for fixed $Re$, $\lambda$ increases with increasing $\theta$, as $\eqref{eq:firstapprox2}$ predicts.
Equation does not hold in detail, however. Most notably, figure \[fig:angles\] shows that when $Re$ is decreased at fixed $\theta$, the wavelength $\lambda$ increases rather than decreases as one would expect from $\eqref{eq:firstapprox2}$. We believe that the force balance holds for all patterns which possess a laminar region free of turbulence, but that the additional approximations made in deriving the simple relationship do not hold over the full range of conditions considered in figure \[fig:angles\]. In particular, the right-hand-side of depends implicitly on $Re$, $\theta$, and $\lambda$ via the dependence of $U_0$, $U_c$, and $U_s$ on these quantities. The approximate functional relationships between $U_0$, $U_c$ and $U_s$ that we have observed in our simulations and on which we have relied in deriving may not hold for other parameter values. Finer adjustments must come from another mechanism.
![Patterns as a function of Reynolds number $Re$ and $\theta$ in a computational domain of size $L_x \times L_y \times L_z= (4/\sin\theta)\times
2 \times 120$. Turbulent-laminar patterns with wavelength $\lambda=40$ ($\times$), $\lambda=60$ ($\bullet$), $\lambda=120$ ($\ast$). Uniform turbulence ($\blacksquare$), intermittent turbulence ($\boxtimes$), laminar Couette flow ($\square$). Wavelengths in computations are constrained to be divisors of 120. Numbers are wavelengths of experimentally observed patterns of Prigent [[*et al.*]{}]{} ([-@Prigent_PhysD], [-@Prigent_IUTAM]).[]{data-label="fig:angles"}](Figures/scat_th_Re.ps){width="11cm"}
The main issue not addressed in our study is closure. We have not attempted to relate the forcing of the mean flow due to Reynolds stresses back to the mean flow itself. In the future we will report on studies employing closure models.
We thank F. Daviaud, O. Dauchot, P. Le Gal, P. Manneville and A. Prigent for helpful comments. The simulations analyzed in this work were performed on the IBM Power 4 of the IDRIS-CNRS supercomputing center as part of project 1119. This work was supported in part by a CNRS-Royal Society grant.
Turbulent-laminar bands in other shear flows
============================================
[|c|cc|cc|cc|c|]{} & & & & PP\
$Re$ & 340 & 395 & 340 & 415 & 303 & 438 & 357\
$\lambda_\text{stream}$ & 110 & 110 & 145 & 95 & 71 & 106 & 103\
$\lambda_\text{span}$ & 83 & 52 & 70 & 35 & 24 & 36 & 45\
$\lambda_z$ & 60 & 46 & 63 & 33 & 23 & 34 & 41\
$\theta$ & $\:37^\circ$ & $\:25^\circ$ & $\:26^\circ$ & $\:20^\circ$ & $\:19^\circ$ & $\:19^\circ$ & $\:24^\circ$\
Turbulent-laminar banded patterns have been observed in a number of shear flows: plane Couette (PC) flow, Taylor-Couette (TC) flow, rotor-stator (RS) flow (torsional Couette flow; the flow between differentially rotating disks) and plane Poiseuille (PP) flow (channel flow). Comparisons between these flows are impeded by the fact that different conventions are used to non-dimensionalise each of them.
In order to compare their observations in Taylor-Couette flow with those in plane Couette flow, [-@Prigent_PhysD] generalise the Reynolds number used in plane Couette flow $U=y/h$ by considering it as based on the shear and the half-gap: $$Re^{PC} = \frac{(\text{Shear}^\text{PC})\;\text{(half-gap)}^2}{\nu} =
\frac{\frac{U}{h} h^2}{\nu} = \frac{U h}{\nu}$$ For flows whose shear is not constant, the average shear is used. We also convert streamwise and spanwise wavelengths to total wavelength and angle of the pattern wavevector via $$\tan(\theta) = \frac{\lambda_\text{span}}{\lambda_\text{stream}} \qquad
\lambda_z = \lambda_\text{span} \cos(\theta)
\label{eq:convert}$$ Table \[tab:exp\_obs\] presents the Reynolds numbers, wavelengths, and angles for which turbulent-laminar patterns have been observed experimentally or numerically. The subsections which follow explain how Table \[tab:exp\_obs\] was obtained from the data in [@Prigent_PhysD; @Cros; @Tsukahara].
Taylor-Couette flow
-------------------
For Taylor-Couette flow between differentially rotating cylinders, the azimuthal and axial directions correspond to the streamwise and spanwise directions of plane Couette flow. For cylinders of radius $r_i$ and $r_o$, rotating at angular velocities $\omega_i$ and $\omega_o$ with $2h\equiv r_o-r_i$ and $\eta\equiv r_i/r_o$, the shear averaged over the gap is $$\langle \text{Shear}^\text{TC}\rangle =
\frac{r_i\omega_i - \eta r_o\omega_o}{(1+\eta)h}$$ leading to the Reynolds number: $$Re^\text{TC} \equiv \frac{r_i \omega_i - \eta r_o \omega_o}{(1+\eta)h} \;
\frac{h^2}{\nu} \approx \frac{Re_i-Re_o}{4\nu}$$ where the last approximate equality corresponds to exact counter-rotation ($\omega_o=-\omega_i$) and the narrow gap limit ($\eta \rightarrow 1$), and $R_i$, $R_o$ are the conventionally defined inner and outer Reynolds numbers, [e.g.]{} $Re_i\equiv 2h r_i\omega_i/\nu$. The wavelengths and Reynolds numbers observed in Taylor-Couette and plane Couette flow are compared in Figure 5 of [@Prigent_PhysD].
Torsional Couette flow
----------------------
The laminar profile for torsional Couette flow between a rotating and a stationary disk (rotor-stator flow) is $${{\bf u}}={{\bf e}}_\theta \;\frac{\omega \,r \,z}{h}$$ and the Reynolds number based on axial shear and half-gap is $$Re^\text{RS}=\frac{\omega r}{h} \;\frac{h^2}{4\nu} = \frac{\omega r h}{4\nu}
\label{eq:Re_RS}$$ For $m$ spirals, the azimuthal wavelength in units of the half-gap is $$\lambda^\text{RS}_\text{stream} = \frac{2\pi r}{m h/2}=\frac{4\pi r}{m h}
\label{eq:lambda_RS}$$ Turbulent spiral patterns which are rather regular occur for a range of angular velocities and radii. In their figures 12, 16 and 18, [@Cros] focus particularly on the radius and gap: $$r = 0.8\times 140\,\text{mm}=11.2\,\text{cm} \qquad
h=0.22\,\text{cm}
\label{eq:rh_RS}$$ The highest and lowest rotation rates for which turbulent spirals are seen are
= 68 = 7.12 && m=6\
\[eq:omegahi\_RS\] = 47 = 4.92 && m=9 \[eq:omegalo\_RS\]
Substituting - and the viscosity $\nu=10^{-2}\,$cm$^2$/sec of water into - leads to the values shown in Table \[tab:exp\_obs\]. The pitch angle of the spirals remains approximately constant at $19^\circ$. We use to calculate $\lambda_\text{span}$ and $\lambda_z$, neglecting the variation in radius.
Plane Poiseuille flow
---------------------
Figure 14 of [-@Tsukahara] shows a visualisation from a direct numerical simulation of plane Poiseuille (PP) flow in a channel with domain and Reynolds number $$L_\text{stream}\times L_y\times L_\text{span} =
51.2\;\delta \times 2\;\delta \times 22.5\;\delta
\qquad
Re_c \equiv \frac{u_c\delta}{\nu} = 1430$$ where $u_c$ is the centerline velocity. The domain contains a single wavelength of an oblique turbulent-laminar banded pattern oriented at $\theta=24^\circ$ to the streamwise direction. (Both the wavelength and the angle are dictated by the computational domain.) Following [@Waleffe_03], we view the Poiseuille profile in the half-channel $[-\delta,0]$, over which the shear has one sign, as comparable to the Couette profile in the channel $[-h,h]$, and thus take $\delta/2$ as the unit of length, rather than $\delta$. The shear is obtained by averaging over $[-\delta,0]$: $$\langle\text{Shear}^\text{PP}\rangle
= \left\langle \frac{du}{dy} \right\rangle
= \frac{u_c}{\delta}$$ For the Reynolds number based on the average shear and half-gap, we obtain $$Re^\text{PP}=\frac{\langle\text{Shear}^\text{PP}\rangle
\;(\text{half-gap})^2}{\nu} =
\frac{\frac{u_c}{\delta}\frac{\delta^2}{4}}{\nu} =
\frac{u_c\delta}{4\nu} = \frac{Re_c}{4\nu} = \frac{1430}{4}=357.5$$
|
Project 28
Project 28 is the name given to a U.S. border protection program that runs along a stretch of the US/Mexican border in southern Arizona. The project, the first phase of a much larger program called the "Secure Border Initiative network" (SBInet), was scheduled to be completed in mid-2007, but did not become operational until late 2007. It involves the placement of 9 high-tech surveillance towers that monitor activity using radar, high-resolution cameras, and wireless networking, looking for incursions to report to the Border Patrol.
In February 2008, authorities said that the project did not work as planned nor did it meet the needs of the U.S. Border Patrol. As a result, the deployment of about of virtual fence near Tucson, Yuma, Arizona, and El Paso, Texas is now projected to be completed by the end of 2011, rather than 2008.
Costs
In September 2006, Boeing won a contractor competition and was awarded a three-year, $67 million contract by the U.S. government to build and operate Project 28. The initial construction phase had an estimated cost of $20 million. Project 28 is the pilot for SBInet, which has a total estimated cost of two to eight billion dollars. If Project 28 is successful, hundreds of towers (an estimate in May 2007 was 850 towers) could be placed on the of the U.S. borders with Mexico and Canada. The Department of Homeland Security (DHS) estimates that the cost to secure each mile of the border with fencing is about $3 million, compared to about $1 million using technology such as that of Project 28.
In a report in February 2007, the Government Accountability Office said that Congress needed to keep a tight rein on the program, because, it said, "SBInet runs the risk of not delivering promised capabilities and benefits on time and within budget." Between 1998 and 2006, the U.S. government spent $429 million on border technology programs that failed.
Technology
Components
The four primary components of the system are the sensor towers, the P28 "Common Operating Picture" (COP), enhanced communications, and upgraded agent vehicles which include a laptop computer and a satellite phone. The project also incorporates unattended ground sensors that will detect intrusions via magnetic, seismic and acoustic sensors and transmit information that will be distributed via the COP.
Each of the -high towers has radar (MSTAR), infrared cameras and other sensors, and data-processing and communications equipment to distribute information to control centers, mobile units, agent vehicles and other law enforcement employees.
Operations
When migrants cross the SBInet's virtual fence, camera and other sensors on the tower are to instantly detect the incursion. These towers then relay real-time electronic images to a private sector communications center. There, a contractor employee will take manual command of the camera, zooming in to identify the number of individuals and their means of transport. After classifying the "threat," the employee will electronically transfer the entrants' coordinates to Border Patrol agents via laptop computers mounted inside Border Patrol vehicles.
Limitations of Project 28
Rather than develop new technology, Boeing took existing cameras, sensors, radar and other equipment and bundled them into a system that although not technologically novel is unlike anything the Border Patrol had used.
Boeing, as the prime contractor, selected nearly 100 of the 900 subcontractors that applied to work on the contract. While Boeing considers the list of subcontractors to be an industrial secret, known subcontractors include Booz Allen Hamilton; Centech, DRS Technologies; Kollsman, Inc.; LGS, L-3 Communications Government Services; Perot Systems, Pinkerton Government Services; Power Contracting, Inc. Reconnaissance Group; Sandia National Laboratories; the Texas Transportation Institute at Texas A&M University; and Unisys.
As of early June 2007, Boeing had issued 55 requests for proposal for additional technologies to be deployed along the border. Jerry McElwee, a Boeing vice president and the program manager for SBInet, said that the June 2007 version of Project 28 was "a demonstration of our approach and a test bed for incorporating improvements" to SBInet.
Test area
Selection
The area where the project is located was the busiest in the sector in fiscal year 2006, according to Border Patrol officials.
"We chose the most difficult, highest-trafficked piece of Arizona because we wanted to take on the challenges that we would have to take on someday," said Brian Seagrave, vice president for border security at Unisys Corporation, the company that is providing the information systems expertise. It also includes a Port of Entry (POE) and is representative of terrain conditions found in large areas along the Southwest border. Unlike other areas on the border that have stadium lighting, fencing and cameras on towers, this area lacks infrastructure and technology.
Location of towers
The nine towers are located on either side of Sasabe, Arizona. Two of the towers are on the land of Tohono O'odham Nation west of the Baboquivari range, three are in the Buenos Aires National Wildlife Refuge, and one is located just outside Arivaca, Arizona, north of the border.
The initial towers are redeployable; at the end of the Project 28 trial, DHS will decide whether to change any locations. The towers will then be moved to the next area being tested, and will be replaced by permanent towers.
Residents of Arivaca who objected to the tower near their town were told in a meeting in May 2007 that the tower was located there because mountains to the south hindered surveillance, and the tower’s closer proximity to the roads near the town would make it easier to maintain. In June 2007, with the system scheduled to become operational shortly, residents were concerned about being under 24-hour surveillance, bright lights in the night sky, and the disruption of recreation and other activities near the tower, including loud alarm blasts from the towers scaring horses on trail rides.
Organizational placement
The of the border near Sasabe that are in Project 28 are the responsibility of the Tucson station of the Border Patrol. The station was arresting 200 to 400 illegal aliens per day as of early 2008.
Progress of the project
Initial testing
In early April 2007, Boeing announced that it had successfully tested the first integrated mobile sensor tower. Dr. Kirk Evans, the SBInet program manager at CBP, said that "The tower and its components functioned as expected, and we are confident that the design is repeatable for deployment along the border."
The project was originally scheduled to be operational on June 13, 2007. System testing began in the first week of June. Agency officials testified publicly on June 7 that Project 28 was on schedule.
Delayed implementation
On June 8, agency officials said that project completion would be delayed until June 20. On June 16, the department said that the project would be delayed beyond June 20.
On June 26, a DHS spokesman could not say when the project would become operational. "We are working hard to resolve these challenges as quickly as possible so that we can deploy or make this system operational and give the agents the tools they need to better secure the border," he said. In mid-July, a DHS spokesman said that programmers were working overtime to make sure the radars, cameras and sensors properly send information to computers in the two command centers and to laptops in Border Patrol vehicles. Boeing is "getting close" but no date has been set for the system to become operational, the spokesman said.
In early September, a spokesman at the Customs and Border Patrol said "It could be two, four, six or eight weeks until it’s operating." Boeing and DHS encountered problems integrating the various cameras, radars and other sensors on the nine towers, and there were also problems combining the incoming data seamlessly with communications networks. Several days later, DHS Secretary Michael Chertoff said he expected to testing to begin in October.
In late October, a senior Boeing official testified that the system was substantially improved. The official said that ""The system is consistently able to slew to new radar targets and successfully record people crossing the border," and that "Camera elevation difficulties have been fixed and a solution for radar display delays has been implemented."
Reduced operational testing
As a pilot project for SBInet, Project 28 was originally scheduled to be operational for eight months. However, in September 2007, DHS Secretary Michael Chertoff said he expected operational testing to finish by the end of the year, a period of less than three months, assuming that the system did go "live" sometime in October.
Acceptance of first phase
In early December 2007, Homeland Security Department conditionally accepted the delivery of the first phase of Project 28 and awarded Boeing a $64 million contract for the next phase. Part of the next phase involves upgrading the Common Operating Picture (COP) system to display real-time information from the radars, cameras and ground sensors that were installed along the borders. The Border Patrol was to take over Project 28 and run it in an operational mode for 45 days. During that time, Chertoff said that "we will identify further adjustments or fixes that need to be made."
DHS officially accepted the system on February 22, 2008.
Effectiveness
In February 2008, U.S. Representative Chris Carney, chairman of the House Homeland Security Committee’s Management, Investigations and Oversight Subcommittee, said the system "works about 30 percent of the time". During a visit in early January 2008 to El Paso, Carney said that he saw an incident where two illegal immigrants crossed in front of a project camera. Carney said that a technician tried to electronically reposition the camera to track them, but the picture was out of focus, the camera moved too slowly, and the illegal immigrants got away.
References
External links
What is Project 28?, U.S. Customs and Border Protection, December 29, 2006
, U.S. Customs and Border Protection
SBInet Virtual Fence, www.arivaca.net
Category:United States Department of Homeland Security |
Dr. Yoon Pak and Xavier Hernandez, Associate Professor and Doctoral Student, Education Policy, Organization, and Leadership, College of Education, University of Illinois at Urbana-Champaign.
Asian Americans in Higher Education: Charting New Realities
The Asian American and Pacific Islander (AAPI) population continues to obfuscate the discourse on diversity and higher education institutions. The historical and contemporary experiences of AAPIs in higher education clearly indicate that their presence has influenced and reinforced the importance of diversity in educational environments. Please join us for this HEC brownbag to hear from the authors and to celebrate the release of a new ASHE monograph, entitled Asian Americans in Higher Education: Charting New Realities. The monograph provides:• A historical overview of the “model minority” stereotype• The affirmative action debate and AAPIs• Their involvement in the education pipeline• A discussion of their experiences in college.Implications for future research, practice, and policy are further discussed. Educators, administrators, faculty, policy makers, and researchers who are concerned with diversity issues and the AAPI population will find this monograph an engaging and valuable resource. SPONSORED BY THE HIGHER EDUCATION COLLABORATIVE SEMINAR SERIES, SUPPORTED BY THE TIMPONE FAMILY ENDOWMENT FUND. |
Introduction {#sec1}
============
Mental health research among Asian American (AA) youth and young adults is fragmented. Numerous studies have shown that AA youth and young adults have higher rates of anxiety, depression, and suicidal thoughts than their White counterparts do ([@bib5]; [@bib11]; [@bib57]). However, AAs have also been found to have rates of mental disorders comparable to other racial/ethnic groups including Whites ([@bib29]; [@bib46]). The mixed data are likely reflective of methodological challenges, including small sample sizes and the variability of AA ethnic subgroups that were surveyed. Nevertheless, even with the lack of clarity of incidence rates of mental health problems among AA young people, it is clear that despite the oft-used label of "model-minority," young AAs are vulnerable to developing mental health problems, at least equally, if not more than other racial/ethnic groups. This vulnerability is further amplified as AAs report significantly lower rates of mental health service utilization than the general population ([@bib1]; [@bib40]).
Previous studies of AA mental health have focused on a single time frame (e.g. elementary school years, college years). The subsequent dearth of longitudinal data precludes analysis of the transition from adolescence to young adulthood for AAs, notwithstanding speculation that this period constitutes a significant worsening of mental distress among AA young people ([@bib42]; [@bib60]). To address this gap, we have followed a cohort of AA youth over the course of four years and documented rates of mental health outcomes over three waves of data collection from 2014 to 2018. In addition, this study examined prominent predictors relevant to AA youth and young adults, including family process (e.g., parent-child relationships, parenting behaviors), peer (e.g., relations and quality), acculturation (e.g., bicultural identity) and race/ethnicity (e.g., racial discrimination). We further organized these predictors into "universal" vs. "group-specific" variables to examine the impact of each cluster on mental health, independently and collectively. A comprehensive model in which all variables are simultaneously accounted would reveal whether group-specific variables exacerbate mental health vulnerability among AAs. These findings are critical for public health and community interventions.
Filipino American and Korean American families {#sec1.1}
----------------------------------------------
While often described as a monolithic group, the AA population consists of over 17 different languages, ethnicities and immigrant histories ([@bib50]). Thus, disaggregating the AA population into ethnic-specific samples can shed light on how mental health varies and changes overtime among AAs as a whole, as well as between specific AA subgroups. The present study examines mental health among Filipino American (FA) and the Korean American youth (KA), respectively the third and fifth most populous communities of AAs in the U.S.
FA and KA have important areas of overlap and distinction. For example, both subgroups are part of the middle class with comparable median incomes and education backgrounds ([@bib50]; [@bib67]), diminishing a confounding class effect in comparative analyses. However, the two groups are notably different with respect to acculturation patterns, family characteristics and processes, and youth outcomes ([@bib17]). For example, FA families are significantly more acculturated than KA families in linguistic, occupational, and residential domains ([@bib51]). Overall, second generation KAs retain their heritage language and live in ethnic communities at higher rates than do second generation FAs ([@bib48]). However, although FA an KA parents both preserve traditional family values, FA parents adhere to traditions in the family more so than KA parents ([@bib14]). The similarities and differences of the two groups provides a strategic opportunity to examine the impact of acculturation and family process on mental health among AA subgroups.
Explanatory factors {#sec1.2}
-------------------
Developmental research locates family process and peer influence at the core of youth development. The integrative model by [@bib24] expands developmental research to include the influences of heritage culture, acculturation, and racial positionality among non-White families to better explain developmental process of youth of color. Guided by the integrative model and its emphasis on the impact of culture and race, this study examines how universal factors and group-specific factors contribute to mental health among AA youth, in addition to several important demographic controls (e.g., ethnicity, gender, nativity and family socioeconomic status \[SES\]). Universal etiological factors are those factors that are predictive of mental health problems among youth, regardless of one\'s racial/ethnic or cultural backgrounds. Group-specific factors are those that have particular salience to respective groups, i.e., in this study among our FA and KA samples.
### Universal Factors {#sec1.2.1}
Family and peer relationships have long been identified to be the most important influences on adolescent attitudes and behaviors ([@bib71]). Accounting for family and peers as the two main developmental contexts for youth (e.g., [@bib30]), we classified the following factors as universal: parent-child conflict, parent-child bonding, parental explicit affection, peer relationship and the number of antisocial peers. The quality of parent-child relationships and parenting remains significant during adolescence and young adulthood even as peer influences are dominant ([@bib38]; [@bib53]; J. D. [@bib61]; [@bib63]). For example, certain aspects of family process, including high parent-child conflict, low parent-child bonding, and low parent affection have been shown to be linked to negative mental health outcomes such as depression and anxiety ([@bib43]; [@bib49]). Similarly, peer factors, such as feeling supported by friends or associating with antisocial peers, are one of the most influential in youth development ([@bib12]; [@bib20]) and have been found to impact mental health outcomes across racial/ethnic groups ([@bib9], [@bib36]).
### Group specific factors {#sec1.2.2}
Beyond the family process and peer constructs applied in most child development research, the family and social contexts may toll extra developmental challenges on AA children and adolescents ([@bib24]). In this study, we considered two domains of constructs that may be group specific and highly relevant to AA families: cultural tensions in the family and circumstances surrounding racial/ethnic minority status. First, to consider cultural tensions within the family, the current study included intergenerational cultural conflict (ICC), gendered norms as exercised by parents, and parental implicit affection (thought to be typical of Asian parents in contrast to Western explicit affection). Second, for racial/ethnic minority status, we focused on acculturative demands and minority stress and included two aspects of social identity (American and ethnic identity) and perceived racial discrimination.
**AA Family Process.** ICC is one of the major stressors among AA young people and thought to be a product of the parent-child acculturation gap, i.e., discrepancy in language, identity, and cultural values and behaviors between parents and their children ([@bib13]). Gendered norms are restrictions typically put on daughters and identified as a source of mental distress in AA family, particularly among AA females ([@bib76]). Several qualitative interviews attest that gendered expectations, in particular the unequal care burden and more inhibitions placed on daughters, have caused distress among AA young women ([@bib22]; [@bib28]). Conversely, parental implicit affection (i.e., parents\' putting child\'s needs before theirs or indirect expression of love that often comes in the form of instrumental support) is a hallmark of AA family process and produces better mental health ([@bib72]; [@bib77]).
**Racial/Ethnic Minority Status.** Minority youth develop a national identity as Americans as they consider their role and position in the U.S. society ([@bib52]). AA youth grow up American, as much as they identify themselves with their ethnic heritages ([@bib18]). Developing a strong American identity is equally important for minority youth because it provides a sense of belonging to a country in which they are growing up ([@bib70] In Press). In fact, being able to function well in both ethnic and dominant cultural norms (i.e., bicultural competence) is associated with stronger cognitive flexibility, more positive family relationships and better mental health ([@bib68]). Ethnic identity has been also shown to be a protective factor for mental health among AAs in urban communities ([@bib55]), although empirical findings are inconclusive ([@bib2]; [@bib64]). In contrast, detrimental effects of racial discrimination on a variety of developmental and health outcomes are unequivocal ([@bib73]). Perceived discrimination reduces self-esteem, breeds hopelessness, builds up chronic stress, and increases morbidity ([@bib25]; [@bib73]). Likewise, racial discrimination has been consistently shown to adversely influence developmental and mental health outcomes among AAs ([@bib6]; [@bib26]).
Present study {#sec2}
=============
In this study, we first documented mental health outcomes of AA youth and young adults -- specifically, depressive symptoms and suicidal ideations -- across three waves of data collected over a 4-year period between 2014 and 2018 and, second, identified several prominent explanatory variables. Specifically, using mixed effect regression models, we (1) examined the rate and trend of mental health outcomes over the waves, while accounting for baseline age (2) added the demographic variables of ethnicity, gender, nativity and family SES, (3) examined predictors organized by each cluster, respectively and then simultaneously, and (4) examined whether the impact of each predictor remains the same over the waves and is similar by ethnicity.
The current study focuses on the significance of family process and race/ethnic status that are thought to be specific to AAs. More specifically, our analyses focused on the extent to which such group specific factors exhibit *additional* power in explaining the study outcomes above and beyond the proportions of variance accounted for (among individual subjects and across time) by those universal family process and peer influences typically used in developmental research. Based on existing literature described above and our previous study on FA and KA youth ([@bib77]), we predicted that both universal and group-specific factors would have a significant impact on mental health outcomes of AAs and that each cluster of the predictors would explain mental health outcomes, largely independently with modest overlaps. Moreover, based on developmental research (e.g., [@bib30]), we expected that the magnitudes of the impact of family process variables (both universal and group specific) and peer influences on mental health would remain significant during the transition from youth to young adulthood. Due to a dearth of empirical studies that compare FA and KA youth, we did not generate hypotheses regarding how predictors would differently influence across our two samples. However, we anticipated that ethnic group differences would be mainly in the averages of the predictors but not in the associations between both universal and group specific predictors and mental health outcomes ([@bib76]).
Methods {#sec3}
=======
Overview of the project {#sec3.1}
-----------------------
Data for this study are derived from the Midwest Longitudinal Study of Asian American Families (MLSAAF) project, a longitudinal survey (3-wave panel data) of FA and KA youth and their parents living in a Midwest metropolitan area (*N* = 1,574 at Wave 1 in 2014; 378 FA youth, 376 FA parents, 408 KA youth and 412 KA parents). We followed all baseline participants in 2016 (78% retention) and youth participants in 2018 (82% of W1). In this study, data from youth surveys are used, *n* = 786 in W1, *n* = 604 in W2 and *n* = 641 in W3. In its initial data collection, all participants resided in four major counties near Chicago (i.e., Cook, Lake, DuPage and Will) and were recruited from multiple sources, including phonebooks, public and private schools, ethnic churches and temples, ethnic grocery stores, and ethnic community organizations. A proactive recruitment campaign continued to reach out to respective communities and organizations until the project reached its target numbers (at least 350 families for each subgroup).
At W1, the majority of participants (84%) were surveyed in-person by trained bilingual interviewers. For self-administered survey, the MLSAAF questionnaires were available both in paper-pencil and online-survey formats and in English, Tagalog and Korean. Data for Waves 2 and 3 were collected using self-administered questionnaires, either online or paper and in three language versions. More details about data collection and procedures are found elsewhere ([@bib18]).
Sample characteristics {#sec3.2}
----------------------
Descriptive statistics for demographic characteristics, predictors, and outcome variables across the three waves are shown in [Table 1](#tbl1){ref-type="table"}. At baseline (W1), the age range was from 11 to 19 years old (but mostly 12--17) and a larger proportion of the samples was enrolled in high school (78.69% FA and 75.25% KA). Although overall similar, FAs were older (15.27 (*SD* = 1.88) vs. 14.76 (*SD* = 1.91)), more girls (56% vs. 47%), more American-born (71% vs. 58%) than KAs. Among foreign-born, the average year of living in the U.S. was 8 years. Unreported in [Table 1](#tbl1){ref-type="table"}, the baseline data showed that a large majority of parents were in mid-40s and currently married. Less than a quarter of the families have ever received free/reduced-price school lunch. Further parental data on education and household income confirmed that our samples are typical of FA and KA family characteristics as reported in the U.S. Census and other national studies such as the Add Health.Table 1Descriptive statistics.Table 1VariablesWave 1Wave 2Wave 3FAKADiff.[a](#tbl1fna){ref-type="table-fn"}Full SampleFAKADiff.Full SampleFAKADiff.Full Sample*Demographic Variables* Ethnicity (%)378 (48.09%)408 (51.91%)n.s.786 (100%)282 (46.23%)328 (53.77%)n.s.610 (100%)308 (47.53%)340 (52.47%)n.s.648 (100%) Age15.27 (1.88)14.76 (1.91)\*\*\*15.00 (1.91)16.71 (1.87)16.39 (1.85)\*16.54 (1.86)18.22 (1.84)17.91 (1.89)\*18.06 (1.87) Female (%)213 (56.35%)193 (47.30%)\*406 (51.65%)165 (59.14%)154 (47.38%)\*\*319 (52.81%)176 (57.89%)167 (49.55%)\*343 (53.51%) U.S.-Born (%)269 (71.16%)237 (58.09%)\*\*\*506 (64.38%)202 (72.40%)198 (60.92%)\*\*400 (66.23%)223 (73.36%)201 (59.64%)\*\*\*424 (66.15%) Family SES3.10 (0.56)3.03 (0.7)n.s.3.07 (0.64)3.00 (0.68)2.85 (0.76)\*2.92 (0.73)3.01 (0.70)2.79 (0.79)\*\*\*2.89 (0.76)*Universal Factors* Parent-child Conflict2.44 (0.93)2.22 (0.79)\*\*\*2.32 (0.86)2.63 (1.00)2.55 (0.94)n.s.2.59 (0.97)2.61 (0.98)2.48 (0.89)^+^2.54 (0.93) Parent-child Bonding3.97 (0.76)4.01 (0.70)n.s.3.99 (0.73)3.74 (0.95)3.73 (0.90)n.s.3.74 (0.92)3.72 (1.00)3.80 (0.97)n.s.3.76 (0.99) Explicit Affection3.8 (0.80)3.76 (0.78)n.s.3.78 (0.79)3.65 (0.93)3.6 (0.87)n.s.3.62 (0.9)3.69 (0.93)3.67 (0.85)n.s.3.68 (0.89) Peer Relation4.44 (0.64)4.43 (0.64)n.s.4.44 (0.64)4.22 (0.79)4.14 (0.85)n.s.4.18 (0.82)3.49 (1.02)3.65 (0.95)\*3.57 (0.99) Peer antisocial Behaviors1.36 (0.40)1.25 (0.3)\*\*\*1.31 (0.35)1.48 (0.53)1.40 (0.53)^+^1.44 (0.53)1.84 (0.72)1.61 (0.62)\*\*\*1.72 (0.68)*Group Specific Factors: AA Family Process* ICC2.60 (0.91)2.37 (0.78)\*\*\*2.48 (0.85)2.49 (1.04)2.27 (0.87)\*\*2.37 (0.96)2.53 (1.03)2.19 (0.85)\*\*\*2.35 (0.95) Gendered Norms2.85 (0.85)2.65 (0.76)\*\*2.75 (0.81)2.84 (0.83)2.65 (0.74)\*\*2.74 (0.79)2.85 (0.85)2.64 (0.75)\*\*2.74 (0.81) Implicit Affection4.35 (0.72)4.27 (0.68)n.s.4.31 (0.7)4.18 (0.83)4.19 (0.8)n.s.4.19 (0.81)4.22 (0.81)4.26 (0.77)n.s.4.24 (0.79)*Group Specific Factors: Racial/Ethnic Minority Status* American Identity3.86 (0.83)3.53 (0.82)\*\*\*3.69 (0.84)3.75 (0.88)3.39 (0.88)\*\*\*3.56 (0.9)3.72 (0.85)3.38 (0.88)\*\*\*3.54 (0.88) Ethnic Identity4.35 (0.64)4.15 (0.7)\*\*\*4.25 (0.68)4.18 (0.8)4.02 (0.78)\*4.09 (0.8)4.21 (0.84)4.02 (0.76)\*\*4.11 (0.81) Racial Discrimination1.35 (0.48)1.49 (0.52)\*\*\*1.43 (0.51)1.41 (0.57)1.54 (0.67)\*\*1.48 (0.63)1.50 (0.60)1.65 (0.68)\*\*1.58 (0.65)*Mental Health Outcomes* Suicidal Ideation38 (10.30%)38 (9.48%)n.s.76 (9.87%)35 (12.50%)41 (12.69%)n.s.76 (12.60%)49 (16.17%)55 (16.37%)n.s.104 (16.28%) Depressive Symptoms1.81 (0.76)1.81 (0.73)n.s.1.81 (0.74)1.89 (0.81)1.97 (0.84)n.s.1.93 (0.83)2.10 (0.82)2.17 (0.84)n.s.2.14 (0.83)[^1][^2][^3]
Measures {#sec3.3}
--------
### Mental health outcomes {#sec3.3.1}
Depressive symptoms were measured by using the Children\'s Depression Inventory ([@bib3]) and the Seattle Personality Questionnaire for Children ([@bib37]). The scale items tap depressive mood as experienced during the last two weeks prior to the survey. Example questions included "I didn\'t enjoy anything at all" and "I felt I was a bad person." The scale showed strong reliability in all waves of survey (α ranging from .93 to .94 across waves for FA and from 0.93 to 0.94 for KA).
To measure suicidal ideations, participants were asked if they seriously have thought about committing suicide during the 12 months period prior to the survey. The response options were yes or no.
### Explanatory variables {#sec3.3.2}
**Universal Factors.** Three aspects of family process were used. *Parent-Child Conflict* was assessed by using 4 items by [@bib54] that ask how often parent and child getting angry at each other, or the parent not listening to child\'s side of the story (α from 0.83 to 0.86 for FA and from 0.79 to 0.82 for KA); *Parent-Child Bonding* items were adopted from the Add Health, assessing the extent to which the child feels close to his/her mom and wants to be the kind of person s/he is at the time of survey (α from 0.88 to 0.93 for FA and from 0.85 to 0.92 for KA); and *Explicit Affection* used the 9 items from [@bib56] Parental Acceptance and Rejection Questionnaires (PARQ) to assess the level of expressed, explicit affection. Examples included "My mom says nice things about me, lets me know she loves me" (α from 0.90 to 0.94 for FA and from 0.90 to 0.92 for KA).
In addition to the measures of family process, two scales measured peer influence. *Peer Relation* refers to the degree to which the respondent was confident they had close peer relationships. The variable was measured by using 3 questions (e.g., having close friends in school, or feeling lonely at school (reverse coded)) used in previous research ([@bib4]). In this study, the scale showed modest reliability (α from 0.60 to 0.68 for FA and from 0.56 to 0.75 for KA). To assess *Peer Antisocial Behaviors*, a 7-item scale was adopted from the Raising Healthy Children (RHC) project ([@bib10]). Respondents were asked, for example, how many of their 10 closest friends have drunk alcohol, skipped school, or smoked marijuana or cigarettes, on a scale ranging from 1 (for none) to 5 (for most of them, 9--10 friends). The scale shows modest to good reliability in both FA and KA samples (α from 0.73 to 0.81 for FA and from 0.66 to 0.79 for KA).
**Group-Specific Family Process Factors.** *Intergenerational Cultural Conflict* (ICC) referes to the degree to which adolescents experience cultural gap from their parents being overly traditional, old fashioned or peculiar with respect to cultural norms. We adopt 10 items developed and used by Lee and his colleauges ([@bib39]). Question items included, for example, "Your parents expect you to behave like a proper Filipino/Korean male or female, but you feel your parents are being too traditional." Reliability was very good (α from 0.89 to 0.92 for FA and from 0.85 to 0.89 for KA). The MLSAAF constructed a 7-item scale of *Gendered Norms* based on its own in-depth interviews with FA families and several qualitative studies ([@bib27]; [@bib22]; [@bib45]; [@bib69]). Specifically, youth were asked about their parents' perception of gendered norms, e.g., "My parents think that girls should not date while in high school." Reliability was good (α = 0.81 for Filipinos and .78 for Koreans). This scale was used only in W1. *Implicit Affection* was measured by 2 items from [@bib41], e.g., "My mom puts my needs before her own needs," "My mom does not often say it but does things that show me she loves me." (α from 0.46 to 0.66 for FA and from 0.56 to 0.58 for KA).
**Group-Specific Race/Ethnic Minority Status Factors.** *American Identity* and *Ethnic Identity* scales were adopted from the Language, Identity, and Behavior (LIB) ([@bib8]), two sets of five parallel items measured the extent to which youth identified themselves as American or Filipino/Korean. Reliability ranged from 0.76 to 0.83 in samples across the waves. *Racial Discrimination* included 5 items from the MLSAAF project and the [@bib52], assessing the frequency of being unfairly treated because of being FA or KA. Examples items included "I have felt discriminated by whites," "by other Asians," or "by other racial/ethnic minorities like Black or Hispanic." (α from 0.74 to 0.83 for FA and from 0.75 to 0.85 for KA).
Analysis steps {#sec4}
==============
To estimate rates and longitudinal changes of the mental health outcomes, mixed effect linear regression models (for depressive symptoms) and mixed effect logistic regression models (for suicidal ideation) were estimated. Using STATA *v*.15.1, regression models included both fixed effects of predictors and random effects of individual variance around the sample parameters. The predictors may be time-variant (e.g., peer relation or ethnic identity) or invariant (e.g., gender or ethnicity). Two modeling methods were considered, i.e. random intercept modeling that allows individuals to have varying level of outcomes at the baseline and random intercept and trend modeling that additionally estimates individual variances in rates of change in outcome measures. We ran both modeling methods for each outcome and used the likelihood ratio (LR) test to examine significant fit increments between these two models. The LR test results were that random intercept and trend modeling showed significant fit increments with the depressive symptoms outcome but did not converge properly with the suicidal ideation outcome. Accordingly, random intercept and trend modeling was used with depressive symptoms and random intercept modeling was with suicidal ideations.
As the first step, unadjusted rates of mental health over three waves were examined by ethnicity and the full sample. In the second step, mixed effects regression models were run on respective outcome, adjusted for the demographic controls. In the subsequent regression models, each of three clusters (i.e., universal, AA family process and racial/ethnic minority status factors) was initially run individually along with the controls. In the final saturated models, all clusters were regressed together. Mixed effects modeling does not generate R-squared. Accordingly, we used and reported Intraclass Correlation to show the proportion of (unexplained) variance of outcome measures at the subject level (i.e., level-2 in longitudinal data format) ([@bib31]). Interaction terms (predictor × wave and predictor × ethnicity) were added to the saturated model, one term at a time, to examine whether the magnitude of the predictors changed over time and varied by ethnicity. The rate of missing data was less than 3% in W1 and W2, and less than 2% in W3, which did not warrant missing data imputations.
Results {#sec5}
=======
Rates & changes over time in mental health problems {#sec5.1}
---------------------------------------------------
Overall, mental health problems increased over the 4 years of data collection period. Specifically, as shown in [Table 1](#tbl1){ref-type="table"} at the bottom rows, unadjusted means of depressive symptoms increased steadly from 1.81 (*SD* = 0.74) in W1, 1.93 (*SD* = 0.83) in W2, to 2.14 (*SD* = 0.83) in W3. Similarly, unadjusted proportion of suicidal ideation increased, and substantially, from 9.67% in W1, 12.46% in W2 to 16.05% in W3. The upward trejectories of mental health problems were consistent in both ethnic subgroups. The descriptive statistics of the study variables are reported in [Table 1](#tbl1){ref-type="table"}, examined at each wave and by ethnicity and full sample.
In [Table 2](#tbl2){ref-type="table"}, results of mixed effect regression models adjusted for the controls are presented. Controlling for the effects of demographics, wave (0, 1, 2) was associated significantly and positively (*b* = 0.72, *p* \< .001) with depressive symptoms indicating a statistically significant increase of depressive symptoms over time, controlling for the demographics. Given the age range of 11--19 of the baseline data, we added an interaction term of wave × age to account for the age effect within the sample. We found a significant effect (*b* = −0.04, *p* \< .001), suggesting a lower rate of increase in depressive symptoms among older repondents than younger repondents. Similar results are found on suicidal ideation. Wave was significantly associated with the odds of having suicidal ideations during the past 12 months (OR = 5.30, *p* \< .001), showing a statistically significant, notably drastic increase in suicidal ideations during the period of data collection, adjusted for the demgraphics. The rate of increase in odds across waves was also more pronounced among younger than older respondents.Table 2Mixed effect models of depressive symptoms and suicidal ideation.Table 2Depressive SymptomsSuicidal IdeationPredictors*b* (SE^ǂ^)*b* (OR[a](#tbl2fna){ref-type="table-fn"})
Waves (0, 1, 2)0.72\*\*\* (0.13)1.67^+^ (5.30)Baseline age0.08\*\*\* (0.01)0.09 (1.10)Wave × Baseline age−0.04\*\*\* (0.01)−0.08 (0.92)Ethnicity (KA = 1)0.08^+^ (0.05)−0.01 (0.99)Gender (Female = 1)0.29\*\*\* (0.05)0.86\*\*\* (2.36)Nativity (US Born = 1)0.09^+^ (0.05)0.16 (1.17)Family SES−0.11\*\*\* (0.03)−0.39\*\* (0.68)
Constant0.42^+^ (0.22)−5.49\*\*\* (0.00)Observations1,9781,965*N* of Individuals775775Intraclass correlation.45.57[^4][^5]
Mixed effect linear regression: Depressive symptoms {#sec5.2}
---------------------------------------------------
### Universal Factors {#sec5.2.1}
The mixed effect models shown in [Table 2](#tbl2){ref-type="table"} were extended to include universal and group specific factors as predictors with results displayed in [Table 3](#tbl3){ref-type="table"}. As expected, all universal factors (the family process and peer influence variables) were significantly related to the level of depressive symptoms in expected directions. Specifically, parent-child conflict (*b* = 0.15, *p* \< .001) and antisocial behaviors among peers (*b* = 0.09, *p* \< .01) were related to higher symptoms, while parent-child bonding (*b* = −0.14, p \< 001), parental explicit affect (*b* = −0.06, *p* \< .05) and positive peer relations (*b* = −0.20, p \< .001) were associated with lower symptom levels.Table 3Mixed effect models of depressive symptoms.Table 3Clusters and PredictorsModel for Universal FactorsModel for Group Specific Family ProcessModel for Racial/Ethnic Minority StatusSaturated Model*b* (SE[a](#tbl3fna){ref-type="table-fn"})*b* (SE)*b* (SE)*b* (SE)*Universal Factors* Parent-child conflict0.15\*\*\* (0.02)0.08\*\*\* (0.02) Parent-child bonding−0.14\*\*\* (0.03)−0.12\*\*\* (0.03) Parental explicit affection−0.06\* (0.03)−0.01 (0.03) Peer relation−0.20\*\*\* (0.02)−0.16\*\*\* (0.02) Peer antisocial behaviors0.09\*\* (0.03)0.04 (0.03)*Group Specific Factors: AA Family Process* Intergenerational cultural conflict0.27\*\*\* (0.02)0.15\*\*\* (0.02) Gendered norms0.01 (0.03)0.02 (0.02) Implicit affection−0.08\*\*\* (0.02)0.02 (0.02)*Group Specific Factors: Racial/Ethnic Minority Status* American identity−0.08\*\*\* (0.02)−0.05\* (0.02) Ethnic identity−0.13\*\*\* (0.02)−0.09\*\*\* (0.02) Racial discrimination0.31\*\*\* (0.03)0.18\*\*\* (0.03)
Constant1.00\*\*\* (0.19)0.44\* (0.20)0.63\*\* (0.02)0.92\*\*\* (0.02)Observations1,9471,9591,9621,928*N* of Individuals773774773771Intraclass correlation.35.39.38.30[^6][^7][^8]
### Group specific factors {#sec5.2.2}
Of the three AA family process variables, ICC (*b* = .27, *p* \< .001) and implicit affection (*b* = −0.08, *p* \< .001) had significant associations with depressive symptoms, also in expected directions. The coefficient of gendered norms was not significant (*p* \> .05), although it was positively correlated with depressive symptom in bivariate analysis (*r* = 0.12, *p* \< .001). All three racial/ethnic minority status variables (ethnic identity *b* = −0.13, *p* \< .001, American identity *b* = −0.08, *p* \< .001, and discrimination *b* = 0.31, *p* \< .001) were significantly related to depression in expected directions.
### Saturated models {#sec5.2.3}
**Main Effects.** In the saturated model (summarized in the last column in [Table 3](#tbl3){ref-type="table"}), all predictors were estimated simultaneously, controlling for the demographics. Three of the five universal factors (parent-child conflict *b* = 0.08, *p* \< .001, parent-child bonding *b* = −0.12, *p* \< .001, and peer relations *b* = −0.16, *p* \< .001) remained significant, while parental explicit affect and peer antisocial behavior were no longer related significantly to depressive symptoms. Regarding the group-specific AA family process factors, only ICC (*b* = 0.15, *p* \< .001) remained significant in the saturated model. Results on the racial/ethnic minority status variables (American identity *b* = −0.05, *p* \< .05, ethnic identity *b* = −0.09, *p* \< .001 and racial discrimination *b* = −0.18, *p* \< .001) were affected little, except a slight reduction in size of the coefficients.
**Interaction Effects.** Inspection of the interaction terms between each of the 11 predictors and wave (not shown in table) demonstrated that the effects of the predictors on depressive symptoms as shown in the saturated model ([Table 3](#tbl3){ref-type="table"}) were consistent across waves, with one exception of the protective effect of peer relations. The beneficial influence of peers relations was strong and significant at W1 (*b* = −0.29, *p* \< .001), marginally increased from W1 to W2 (*b* = −0.32, *p* \< .001), but eventually became none-significant at W3 (*b* = −0.03, *p* \> .1).
Two of the predictor × ethnicity interaction terms was statistically significant at *p* \< .05 level. First, ICC was a positive and stronger predictor for FA (*b* = 0.21, *p* \< .001) than for KA youth (*b* = 0.07, *p* \< .05), which was also statistically significant. Second, the coefficients of parental explicit affection differed by ethnicity but were not statistically significant in either group.
Mixed effect logit regression: Suicidal ideation {#sec5.3}
------------------------------------------------
### Universal Factors {#sec5.3.1}
Results of the mixed effect logit regression models of suicidal ideation are reported in [Table 4](#tbl4){ref-type="table"}. Of the universal factors, parent-child bonding (OR = 0.71, *p* \< .05) and peer relations (OR = 0.64, *p* \< .001) were related to the lower probability of having suicidal ideation, while peer antisocial behaviors (OR = 1.54, *p* \< .05) were significantly associated with higher probability of having suicidal ideation.Table 4Mixed effect models for suicidal ideations.Table 4Clusters and PredictorsModel for Universal FactorsModel for AA Family ProcessModel for Racial/Ethnic Minority StatusSaturated Model*b* (OR[a](#tbl4fna){ref-type="table-fn"})*b* (OR)*b* (OR)*b* (OR)*Universal Factors* Parent-child conflict0.20 (1.22)−0.02 (0.98) Parent-child bonding−0.35\* (0.71)−0.25 (0.78) Parental explicit affection−0.20 (0.82)0.01 (1.01) Peer relation−0.45\*\*\* (0.64)−0.32\*\* (0.73) Peer antisocial behaviors0.43\* (1.54)0.21 (1.23)*Group Specific Factors: AA Family Process* Intergenerational Cultural Conflict0.78\*\*\*(2.19)0.57\*\*\* (1.76) Gendered norms−0.24 (0.78)−0.21 (0.81) Implicit affection−0.34\*\* (0.71)−0.12 (0.89)*Group Specific Factors: Racial/Ethnic Minority Status* American identity−0.13 (0.88)−0.08 (0.93) Ethnic identity−0.68\*\*\* (0.51)−0.53\*\*\* (0.59) Racial discrimination0.96\*\*\* (2.61)0.62\*\*\* (1.85)
Constant−3.70\*\* (0.02)−5.18\*\*\* (0.01)−4.55\*\* (0.01)−3.87\*\* (0.02)Observations1,9331,9461,9491,914*N* of Individuals773774773771Intraclass correlation.47.53.52.48[^9][^10][^11]
### Group specific factors {#sec5.3.2}
Similar to the results of depressive symptoms, ICC (OR = 2.19, *p* \< .001) and implicit affection (OR = 0.71, *p* \< .01) were significantly related to the odds of suicidal ideation in expected directions. Of racial/ethnic minority status factors, American identity was not significant, whereas ethnic identity (OR = 0.51, *p* \< .001) showed a significant effect in reducing suicidal ideation. Racial discrimination had a noticeably large and adverse effect on suicidal ideation (OR = 2.61, *p* \< .001).
### Saturated models {#sec5.3.3}
**Main Effects.** The saturated model shows that of the universal factors, parent-child bonding and peer antisocial behaviors were no longer statistically significant and only peer relations remained significant to lower odds of having suicidal ideations (OR = 0.73, *p* \< .01). Three group specific variables remained significant. That is, ICC (OR = 1.76, *p* \< .001), ethnic identity (OR = 0.59, *p* \< .001), and racial discrimination (OR = 1.85, *p* \< .001) were statistically significant in the final saturated model in expected directions.
**Interaction Effects.** None of the interactions of predictor by wave was statistically significant in the saturated model of suicidal ideation. The interaction terms of predictor × ethnicity indicated that ethnic identity was a significant and negative predictor of suicidal ideation only among KA youth (OR = 0.42, *p* \< .001).
Discussion {#sec6}
==========
This study provides unique and much needed longitudinal data on mental health outcomes among AA young people during the developmental transition from adolescence to young adulthood. At the time of initial (baseline) survey in 2014, most of the youth participants were in early-to mid-adolescence (12--17 years of age). By W3 in 2018, they were in either late adolescence or emerging adulthood. Within this context, our data substantiated a troubling upward trend in mental health struggles among young AAs during the transition. Adjusting demographic controls did not change the pattern. Moreover, this study shows that mental health problems among AA young people have not only increased but also became more serious in severity as noted by the substantial increase in suicidal ideation (9.87% to 16.28%). In fact, 22% of 18 and 19 year old youth in W3 reported suicidal ideation, twice as many as the national average of 11% among the same age group in 2017 ([@bib65]), revealing an alarming public health concern. Finally, this study demonstrates that these trends are shared by FA and KA samples.
With respect to the etiology of mental distress and its significant increases, our results from the mixed effect regression models confirmed the validity of the universal family process and peer influences. We found that the quality of parent-child relations as well as peer influences all had unique and independent associations with the level of depressive symptoms, controlling for gender, age, family SES, and the place of birth of participants. Parent-child bonding and conflict and peer relations, in particular, remained robust for depressive symptoms when group-specific factors were estimated together. We also found that peer relations seem to exert greater influence on suicidal ideation. Thus, data of this study suggest that parent-child relations and expressed affection in AA families matters importantly for internalizing distress such as depressive mood symptoms from adolescence through emerging adulthood but that they may not be as powerful for extreme conditions such as suicidal thoughts. Among AA youth samples, universal factors are seldom tested separately from group specific factors for their predictive roles in AA youth outcomes. This study underscores the extensive role of universal factors, notably in AA depressive symptoms, and lays the groundwork for future research in this area.
A central motive of this study was to examine the additive, complementary contributions of group (or culture) specific factors to accounting for variances in depression and suicidal ideation, above and beyond the variances accounted for by the universal family factors and peer influences. These factors were grouped into AA family process factors and those relevant to racial/ethnic minority status. We find that the group specific factors were complementary. That is, effects of universal and group specific factors on outcomes were unique and additive, so that the addition of group specific factors into the model caused little changes on the significance of universal factors. In our view, to explain the elevated vulnerability of mental distress among AA youth, it is pivotal for research of AA families and children to identify and integrate culture- and context-specific constructs in addition to conventional measures of family process and peer relation. This process requires firm theoretical specifications and empirical supports of cultural traits and social and historical contexts of ethnic groups under investigation. This study is one of the early endeavors.
In analyses, we considered three group specific AA family factors -- ICC, gendered norms, implicit affection, and found that ICC made considerable contributions to accounted variances in depressive symptoms and suicidal ideation. Indeed, it was the only one of the three AA family process factors considered that was related to the outcomes after all other clusters of predictors were estimated together in the final saturated models. ICC has been cited as one of the major stressors among AA youth who are referred to mental health services (Lee et al., 2017). While all American families may go through cultural transitions and experience generational gap in values and norms, AA families may encounter additional conflict from the disparity between traditional Asian and American cultures. Results of this study confirm that ICC does play an important etiological role with respect to depression and suicidal ideations among AA adolescents and young adults. Relatedly, although parental gendered norms were not a significant predictor of mental distress in multivariate regressions of this study, they were a significant and positive correlate of mental health problems. Gendered norms emerged as one of the major sources of strain and ICC in several focus groups conducted with FA and KA youth ([@bib17]) and was a significant predictor of mental distress when estimated without ICC ([@bib76]). Moreover, gendered norms were available only in W1 and with additional data, we might have found a significant association. Thus, despite its insignificant association in this study, the importance of gendered norms in AA family should not be dismissed. Implicit affection was a significant protective factor of mental distress among AA youth. However, when parent-child bonding and explicit affection are accounted together, it was no longer significant. This may suggest a possible mediation mechanism, in which parental explicit and implicit affections increase parent-child bonding that can help AA mental health. It is plausible that implicit affection may exert its positive influence indirectly by fostering positive parent-child relation. Indeed, a recent study highlighted the benefit of implicit affection in enhancing mental health and improving academic performance among FA and KA youth ([@bib77]).
Of the group specific factors, explanatory powers of racial/ethnic minority status factors were highlighted in this study. The significant roles of racial/ethnic status variables changed little when other clusters were accounted for, thus were independent of family and peer contexts. Consistent with the bicultural model of acculturation ([@bib7]), both American and ethnic identities appeared to be critical resources suppressing depressive symptoms, and ethnic identity for both mental health outcomes. Ethnic identity, in particular, has been investigated intensively with respect to its direct contribution to psychological and developmental outcomes, and as a moderator that buffer adverse consequences of stressful life conditions and of experiences of social exclusion ([@bib59]; [@bib62]). The results of this study suggest that as it reduced general depressive mood, ethnic identity may help minority adolescents remain hopeful in the midst of severe distress and avoid drastic thoughts. On the contrary, American identity does not seem to be as beneficial in fighting severely distressing thoughts that are most likely to have social origins such as systematic exclusion and marginalization of AAs. Our findings call for systematic investigations to ascertain determinants of ethnic identity.
As well, the findings of this study extend a line of empirical research on etiological salience of discrimination, i.e., its pernicious impact on mental health (e.g., [@bib73]; [@bib74]) and particularly in exacerbating serious mental distress. Furthermore, few studies examined the role of discrimination in combination with family process and peer factors among AA youth. In addition, to our knowledge, this study is the first, or among few, that considered discrimination and suicidal ideation using longitudinal data from adolescents of racial minority communities in the U.S. It should be noted that the period that this data collection occurred coincides with the documented surge of racist and anti-immigrant sentiment ([@bib23]), which is consistent with youth report of perceive racial discrimination that may have exacerbated mental health vulnerabilities among the study sample.
When we inspected the interaction terms to evaluate changes in the predictive impact of each predictor on mental health outcomes, we found that the statistical significance of most predictors did not change and were consistent across the three waves of survey. One exception was a diminished impact of peer relations on depressive symptoms, although its impact on suicidal ideation remained significant over the transition into adulthood. The diminishing role of peers on depressive symptoms was unexpected. It may be that as AA adolescents complete high school and begin more independent living in college or in job market, the nature of contributing etiological processes may shift away from immediate peer relations to more diverse and complex social interactions. The findings may also indicate a particular significance of family or an elevation of risk in other aspects among young AAs. For example, parent-child conflict and perceived racial discrimination significantly increased from W1 to W3, while positive peer relations declined. Leaving the family home during emerging adulthood is expected to result in more freedom, less parent-child daily conflict, and better parent-child relations ([@bib21]; [@bib47]; [@bib58]). This study shows that it may not be the case for AA late adolescents and young adults. In addition to increases of parent-child conflict, its impact remains significant. It may be due to Asian collectivism that expects grown-up children to maintain interdependence and fulfill their family obligations ([@bib34]), which may be amplified in the process of deciding on a higher education or a career.
Overall, results were more similar than different between FA and KA youth. However, a few important distinctions remain. ICC was stronger for FA. Moreover, both ICC and parent-child conflict were significantly higher among FA than KA in all three waves. This may suggest that in addition to higher conflicts in the FA families, FA youth are more influenced by parent-child relations; further analysis is needed to determine its correlates with a stronger emphasis on the centrality of family among FAs, compared to KAs, found in previous studies ([@bib14]). Finally, although the rates of ethnic identity were significantly higher among FAs than KAs in this study, ethnic identity was a stronger protective factor of suicidal ideation for KA youth versus FA youth. KA communities are tightly-knit, demonstrating higher rates of ethnic segregation and language retention than FA communities ([@bib44]). It is plausible that a strong ethnic community facilitates the buffering effect of ethnic identity more so than growing up in a more integrated community. Still, ethnic identity was a protective factor for depressive symptoms for both groups, demonstrating its value in both groups. As these interactions were for exploratory purposes, these difference merit further research into causalities and implications for clinical interventions.
Some studies reported that FA youth, especially females, have a significantly higher rate of mental distress ([@bib19]), while others showed equally high mental health problems among KA and FA ([@bib35]). The present study found that the rates of mental health distress are comparable across FA and KA young people, although FA girls did report the highest rate of depressive symptoms in W2. Some of the inconsistence in the reports may be due to differences in sampling strategies utilized, targeted developmental period or timing of the data collection. The Add Health, first collected in 1994, was a school-based, nationally representative survey likely to have included a wide variance of FA youth. The MLSAAF, from which this study used the data, started in 2014 and was a regional study with limited variance among its participants; FA parents in particular expressed reluctance to consent when they supposed that the survey would cast a negative image of FA youth. Survey is collected only from willing participants and families whose children struggle are less likely to consent to participate. Likewise, it is plausible that FA parents of children with difficulties such as mental distress may have deferred from participating and if FA girls indeed have more problems, FA families with daughters might have been less willing to participate.
A few limitations of the study should be mentioned. First, although parental demographic characteristics of this study\'s samples are comparable to those of national data, the generalizability of this study remains limited. Relatedly, caution is advised in applying the study findings to other AA subgroups than FAs and KAs. Moreover, measurements of a few constructs are new and had a less than ideal reliability, e.g., implicit affection. Nevertheless, these relatively new scales have been used in recent studies (e.g., [@bib15];[@bib76]) and have provided important information. With an improved quality, these measures could have shown additional significant or stronger associations.
Notwithstanding these limitations, the major contributions of this study include the large-scale community samples as well as the longitudinal design. The study fills a gap in the literature in which studies solely examine a single time frame and clarifies how the rates of negative mental health outcomes change over time among AAs during the transition from early adolescence to emerging adulthood. Much less is known about the relative roles of family and peers in an immigrant context. This study also demonstrated how the nuanced experiences and cultural processes of AA subgroups could lead to this mental health trend and, in order for appropriate and effective public health interventions to be done, these nuances and specificities must be thoroughly understood.
Implications and future directions {#sec7}
==================================
The question of how culturally-specific variables and universal phenomena affect young AAs is especially urgent given the documented tendency of such youth to mask detrimental internalizing behaviors with academic achievement and low externalized behaviors ([@bib77]). This study provides a comprehensive view of both universal and culturally-specific predictors over several waves, and finds that ICC and racial discrimination may be key risk factors while ethnic identity serves as a protective factor of mental health.
Clinical interventions can implement this research through a family systems approach that targets ICC and parent-child conflict. Further, racial discrimination should be acknowledged as a notable stressor for AA youth. Due to a complicated combination of racial/ethnic stereotypes including the popular model minority stereotype and the perpetual foreigner stereotype in which AAs are regarded as a foreigner regardless of nativity and years of residence in the U.S. ([@bib66]; [@bib75]), AAs are rarely part of the national discourse around recent reports of surging racist and anti-immigration sentiments. Yet, AAs have been disproportionately targeted by racist actions. For example, racist and anti-immigrant hate crimes targeting AAs across the nation hiked 20% between 2016 and 2017 more than for any other major racial/ethnic groups in the U.S. ([@bib23]). This troubling trend and accumulating evidence for the detrimental effect of racial discrimination on AA mental health calls for appropriate responses in terms of policy, clinical interventions, and family education.
For example, congruent with a critical race perspective, [@bib33] urge an increased "critical awareness" of AA history and heritage culture history, White racism, racial inequity in institutions and society. Most importantly, they suggest how parents can help translate what critical awareness means for youth personally ("reflection") and how they might encourage youth to actively resist inequitable systems ("activism"), as a way to combat racism and racial discrimination.
Ethnic identity, despite some mixed reports on its role on youth development, is an important protective factor to mental health among AAs. Several studies have shown its mitigating effect and particularly the buffering role it plays with respect to racial discrimination. Culturally competent clinical interventions will take into account the salutary effects of a strong ethnic identity. However, current research is limited to offer effective methods of building and enhancing healthy sense of ethnic identity. We recommend systematic research on familial and social determinants of ethnic identity, especially the sense of pride and esteem in ethnic roots and heritage, possibly through an effective ethnic/racial socialization in the family ([@bib32]). Considering the drastically increased rates of suicidal ideation in W3 and the sustained significance of ICC, ethnic identity and racial discrimination in suicidal ideations, there seems to be an urgent need to determine both positive and negative etiology of mental distress, especially suicidal thoughts and attempts, among those entering emerging adulthood and how family, peer and society together can mitigate this serious vulnerability.
Ethical statement {#sec8}
=================
The study was conducted in accordance with the ethical standards, approved by the University of Chicago IRB.
CRediT authorship contribution statement {#sec9}
========================================
**Yoonsun Choi:** Writing - original draft, Conceptualization, Methodology, Investigation, Funding acquisition. **Michael Park:** Writing - original draft, Formal analysis. **Samuel Noh:** Writing - original draft, Conceptualization, Funding acquisition. **Jeanette Park Lee:** Writing - original draft. **David Takeuchi:** Conceptualization, Funding acquisition.
Appendix A. Supplementary data {#appsec1}
==============================
The following is the Supplementary data to this article:Multimedia component 1Multimedia component 1
This study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD, R01 HD073200, PI: Yoonsun Choi).
Supplementary data to this article can be found online at <https://doi.org/10.1016/j.ssmph.2020.100542>.
[^1]: \*\*\**p* \< 0.001; \*\**p* \< 0.01; \**p* \< 0.05.
[^2]: Note. Means (Standard Deviations) for continuous variables or sample numbers (proportions in %) for categorical variables.
[^3]: Statistical differences between FA and KA.
[^4]: \*\*\**p* \< 0.001; \*\**p* \< 0.01; \**p* \< 0.05.
[^5]: SE is standard error; OR Odd Ratio.
[^6]: \*\*\**p* \< 0.001; \*\**p* \< 0.01; \**p* \< 0.05.
[^7]: The models were adjusted for controls (shown in [Table 2](#tbl2){ref-type="table"}) but the coefficients are not reported.
[^8]: SE standard error.
[^9]: \*\*\**p* \< 0.001; \*\**p* \< 0.01; \**p* \< 0.05.
[^10]: The models were adjusted for controls (shown in [Table 2](#tbl2){ref-type="table"}) but the coefficients are not reported.
[^11]: OR Odd Ratio.
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Indonesia: Forest burning and punished victims. The tragedy of the Delang indigenous community in Lamandau, Central Kalimantan
A ban on indigenous Delang traditional fire-fallow cultivation puts a threat to their food sovereignty and cultural fabric. Despite that most forest fires in Indonesia started within expanding oil palm plantation concession areas, companies are not being persecuted. The Delang however have decided to resist.
On a journey from Palangkaraya to Nangabulik, the capital of Lamandau Regency in Central Kalimantan, you see a monotonous landscape: oil palm plantations. If you continue the journey to the border of West Kalimantan, you will come across a hilly area with rather dense forest. Delang indigenous peoples live there. Delang is also the name of the district in Lamandau Regency, Central Kalimantan, which is a buffer area for Lamandau Regency with protected forests and Bukit Sebayan (the Sebayan Hill). It is believed to be a sacred place, where the ancestors of Kaharingan, the ancient religion and peoples of the place, used to live.
Delang indigenous community has long been known for their opposition to various destructive investments in their forest and environment, such as oil palm plantations, mining and forest concessions. Most villages at Lamandau Regency and Central Kalimantan in general, however, have already lost their forests.
Since before the Republic of Indonesia existed, up until today, Delang people have been contributing to forest protection. However, unfortunately, they are being punished instead of rewarded for their valuable contribution. The government banned their traditional fire-fallow cultivation (also called ‘slash and burn’ or swidden cultivation) after vast forest fires rampaged several provinces of Indonesia in 2015.
The blanket banning of shifting cultivation was put in place without any alternative being provided. The ban also contradicts the fact that the ancient practice of swidden farming is protected by environmental protection and management Law. Article 62 of the law allows indigenous communities to carry out fire-fallow cultivation on a maximum area of 2 hectares per family for planting local crop varieties and by building a ditch to prevent fire spread.
Banning shifting cultivation farming without providing any alternative is a tragedy for the Delang community. They have become victims of forest fires and forest clearing by corporate burning. However, instead of receiving recovery support or compensation for damage caused by others, they have been punished. The government, using police and the army, harasses them, threatens villagers with many years of imprisonment, terrorizes communities with water bombs thrown from helicopters. The water used was sourced from fish ponds traditionally used by communities: their ponds were emptied and the water poured back at them in the water bombing.
Forest and land burning in Central Kalimantan
Forest and land fire incidents have been increasing in Indonesia in the last decade. In 1997 and 1998, forest and land fires were spotted in Sumatera, Kalimantan and Papua, with more than 2 million hectares of peatland having been burnt. These fires became one of the biggest contributors of greenhouse gas emissions in Indonesia. (1) In 2015, forest and land fires took a total area of 1.7 million hectares (2), of which 770,000 hectares were in Central Kalimantan and 35.9% of this was peatland. (3)
Forest and land fires in Central Kalimantan have been recorded since 1992, which coincides with the development of oil palm plantation in Kotawaringin Barat and Kotawaringin Timur Regency. (4) Forest and land burning in Central Kalimantan has three interconnected major factors, namely 1) deforestation and degraded land due to logging, 2) uncontrolled oil palm plantation expansion and 3) corporation’s control over an expanding area of land.
80 per cent of forests in Central Kalimantan have been converted into oil palm plantation or been destroyed through mining, the highest figure of deforestation in Indonesia. (5)
Central Kalimantan’s forestry office affirms that in 2010 there were more than 7 million hectares of degraded land, mainly due to logging activities. The Watershed Management office of Kahayan emphasized that 7.27 million hectares of the remaining Central Kalimantan forests have been destroyed, with a deforestation rate of 150,000 hectares per year. (7) Logged forests and degraded land with scrub are prone to fires. (8) Large fires are less common in intact tropical forests and, only after a prolonged dry season, these forests would become more vulnerable. Central Kalimantan’s government adopted a policy that stipulated that oil palm plantations are supposed to only expand on “degraded land”, however, in reality, intact forests have also been converted into oil palm estates. (9) The change in forests and climatic events like “El Niño” have aggravated forest fires in the last 20 years. (10)
Oil palm plantation companies began their operations in Central Kalimantan in 1992. Regional regulation essentially facilitates oil palm investment in the region. (11) As a result, massive expansion of oil palm plantations took place unchecked. Forest and agricultural land, including peatland, have been converted without hesitation. The total allowed conversion area covers almost the same or a bigger area than that of the regency itself. This reveals an out-of-control permit issuance. In 2012, at least 5 regencies issued land conversion permits to companies that covered equal or bigger areas as the administrative regency itself.
Lamandau Regency, where Delang people live, is one of these regencies. With a total area of 641,400 hectares, the Lamandau Regency authority issued permits to corporations covering a total area of 530,526 hectares. Barito Utara Regency issued permits covering a total area of 1,452,468 hectares, whilst the actual size of the regency is only 830,000 hectares. Kapuas Regency issued permits for 1,761,579 hectares on a total size of 1,499,900 hectares. Gunung Mas Regency issued permits for 996,251 hectares for an actual size of 1,080.400 hectares. Barito Timur Regency issued permits for 359,043 hectares on an actual size of 383,400 hectares. (12)
The Indonesian NGO WALHI Central Kalimantan noted that corporations control 12,7 million hectares of a total 15.3 million hectares of land – more than 80 per cent of the province. They acquired control through logging, oil palm plantation and mining concessions. (13) Many land and forest fires started within these concession areas. In 2015 WALHI recorded 17,676 hotspots in Central Kalimantan, with the majority of those located in corporate concession areas.
A 2008 study by Pasaribu, S.M and Friyatno Supena explained that the cause of fires in Kalimantan was associated with land clearing to establish plantations. According to the study, traditional shifting cultivation systems also contributed to land fires, although only 20 per cent. (14)
Indigenous communities as shield
The majority of land and forest fires have been located inside big companies’ concessions. Yet, there is little legal persecution. WALHI Central Kalimantan noted that only 30 corporations were investigated and 10 of these cases are already closed without the companies having been held responsible. None of their cases were followed up. (15) At the national level, the central government listed 413 companies allegedly involved in a total area of 1.7 million hectares and only 14 were sanctioned. Further, WALHI explained, law enforcement has not yet touched the big actors which are involved in vast area of forest burning. Those include Wilmar Group, Best Agro International, Sinar Mas, Musimas, Minamas and Julong Group. They control land use not only through their own concessions but also through the purchase of crude palm oil from mid-size and small companies and profit from land and forest burning on these smaller companies’ land. Sanctions and legal persecution are random and selective. (16) In Central Kalimantan, the big companies involved in forest burning include Sinar Mas and Wilmar. (17)
Land clearing using mechanical equipment is twice as expensive as by fires. (18) Oil palm companies employ local people to clear the land through burning. (19)
Research by Bambang Hero, a lecturer at the Forestry Department of Bogor Agriculture Institute, revealed that in 2015 many corporations employed local people to clear land using fire. Companies are using them as a ‘human shield’ to prevent legal consequences from using fire to clear the land and forest. When the team to verify fire incidence visited the site, the companies would claim that the cleared land belonged to the local community. Six months later, the very land would have changed hands to the corporation and local people who were blamed for clearing the land were nowhere to be seen. (20)
There is a systematic attempt to portray corporate crime as individual crime by putting the blame on indigenous or local communities. The regulation that protects local indigenous farming practices is used to shape public opinion so local customary communities are blamed for forest burning, even where the fires are a result of clearing within concession areas.
Instead of enforcing the law, the government prefers to punish indigenous communities, including the Delang people, for alleged crimes they have not committed. Central Kalimantan’s regulation protecting indigenous Dayak communities’ traditional farming practices was revoked by Government regulation No.15/2015. ‘No burning’ signs were posted on every street corner. The army and police were sent to villages to check and harass people. Those indigenous groups who continued to practice slash-and-burn farming were terrorized, water bombs were dropped from helicopters to put out the fires used within their traditional farming systems.
Victims are punished
The indigenous Delang community is the victim. They have been exposed to the dangerous smoke of forest and land fires that originate in the concession areas controlled by the corporations. They also have taken the brunt of the expansion of the oil palm industry, which resulted in severe economic pressure on Delang peoples and their traditional economies.
In the last 10 years, in addition to losing land to oil palm plantations, the Delang have been exposed to economic pressure due to government policies that are not supportive to local people. They include (1) the drop of the rubber price, (2) the appropriation of community living spaces through designation of villages into forestry areas, (3) deforestation and climate change, (4) the expansion of monoculture oil palm plantations, and (5) environmental degradation through illegal logging by companies.
Rubber is the main crop from which Delang indigenous community generates income, besides rice, dogfruit and fruits. Since the government banned the export of raw rubber, the price has fallen from 20,000 rupiah in 2009 to 5,000 – 6,000 rupiah nowadays.
The issuance of excessive permits for corporate activities resulted in high deforestation rates. Loss of forest has also changed the micro-climate, which in turn affects farming cycles, too. This complicates traditional agriculture. Prolonged rainy seasons and extreme dry seasons lead to a drop in productivity and failed harvests. Unlike before, rice harvests are no longer sufficient to live on for a year. An increase in insect outbreaks further aggravates the situation.
Before oil palm arrived in the area, rice grew well and gave a good yield. There was no insect outbreak. Now, rats and bugs attack people’s gardens and have become serious problems. Fruit trees are replaced by oil palm and bees are gone, which has led to a drop in fruit and honey production. On top of this, illegal logging is rampant in the area adjacent to the Delang land, especially after two logging companies started their operation there.
The economic situation of Delang people is dire. Many have sold their land to ease economic problems. The government is adding to the problems by banning traditional farming. People are afraid of the police and the military in charge of enforcing the ban, and yet, in order to survive, people have to farm wherever take-over from corporate concessions has left a little space and opportunity. Because of that, often the harvest is poor. Some dare to carry on with swidden farming. Due to these economic pressures, many have to look for work outside the villages.
Delang people have been treated unjustly. They are not the culprits of forest and land fires. They burn and clear their own fields. People’s fields are not concession land. A field is a small plot of land, less than one hectare, whereas concession land can be hundreds to thousands of hectares in size. Farming is for subsistence, not for profit. There have never been large forest fires in Delang due to their traditional small farming practices. Delang people (and Dayak peoples in general) apply a “fencing” system when practicing shifting cultivation, guided by strict indigenous rules and hefty fines for violators. Each household can only manage one hectare of land and the burning is managed collectively. It’s a significantly different practice to the way corporations use fire, where thousands of hectares of land and forests are burned without any capacity to control it.
The ban of traditional farming is not only denying people’s right to food sovereignty and rights to a livelihood, but it also decimates the social and cultural fabric of indigenous communities that is connected to these farming activities. People are frustrated with the economic pressure they are facing and with the government policies that put even more pressure to them and jeopardize their livelihoods. In the end, the Delang have decided to resist. They will carry on with traditional swidden farming and they are ready to be put into jail together. |
1. Field of the Invention
This invention relates to mortar compositions, and more particularly to a dry mix mortar composition which can be utilized for a variety of purposes for both interior and exterior use.
2. Disclosure Statement
Mortar additives used to modify the concrete to make it more suitable for the work at hand, to gain some economic advantage or to modify the cement for particular application in a manner which would be impossible without the use of the additive are well-known. For example, it is common practice to incorporate certain additivies into cement compositions to accelerate or increase strength development, retard or accelerate initial set, inhibit corrosion of metals imbedded in the cement, as well as many other desired effects. Some additivies are known to effect more than one property of concrete and, commonly, will beneficially effect one property to the detriment of another.
Certain organic compounds, such as organic surfactants, have been commonly used as water reducing agents and have been applied in both liquid and powder form. Such commonly used surfactants include the aryl and alkyl aryl sulfonates. The following listed patents each disclose the addition of surfactants into cement compositions:
______________________________________ Patent Nos: Issued Inventor ______________________________________ 3,607,326 9/21/71 Serafin 4,080,217 3/21/78 Falcoz et al 4,137,088 1/30/79 Debus et al 4,164,426 8/14/79 Sinka et al 4,205,993 6/3/80 Rosenberg et al 4,209,336 6/24/80 Previte. ______________________________________
In U.S. Pat. No. 3,769,051, issued Oct. 30, 1973, by the present inventor, a liquid additive for mortar is disclosed which is able to retard the setting and increase the workability of mortars. This additive is in liquid form and is to be added to the cement and masonry sand at the job site with the correct amount of water. However, it is difficult for the users of the mortar to mix the correct amounts of water and liquid additive therein to provide for the improved results. Accordingly, the improved results which are realized by adding the appropriate amounts of liquid additive according to the teachings of the patent find only a moderate and uneven success during actual application on the job site.
In spite of the fact that numerous mortar additives have been proposed, a need still exists for a mortar composition which can be used for a variety of purposes and which can include a surfactant pre-mixed in dry form to the proper consistency before the water and other optional liquid containing additives are included at the job site. |
Q:
What is an exact measure of sparsity?
I am currently working on compressed sensing and sparse representation of signals, specificly images.
I am frequently asked "what is sparsity definition?". I answer "if most elements of a signal are zero or close to zero, in some domain like Fourier or Wavelet, then this signal is sparse in that basis." but there is always a problem in this definition, "what does most elements mean? Is it 90 percent? 80 percenct? 92.86 percent?!" Here is where my question arises, is there any exact, i.e. numerical, definition for sparsity?
A:
"Is there any exact, i.e. numerical, definition for sparsity?" And by numerical, I understand both computable, and practically "usable". My take is that: not yet, as least, there is no consensus, yet there are some worthy contenders. The first option "count only non zero terms" is precise, but inefficient (sensitive to numerical approximation and noise, and very complex to optimize). The second option "most elements of a signal are zero or close to zero" is rather imprecise, either on "most" and "close to".
So "an exact measure of sparsity" remains elusive, without more formal aspects.
One recent attempt to define sparsity performed in Hurley and Rickard, 2009 Comparing Measures of Sparsity, IEEE Transactions on Information Theory.
Their idea is to provide a set of axioms that a good sparsity measure ought to fulfill; for instance, a signal $x$ multiplied by a non zero constant, $\alpha x$, should have the same sparsity. In other terms, a sparsity measure should be $0$-homogeneous. Funnily, the $\ell_1$ proxy in compressive sensing, or in lasso regression is $1$-homogeneous. This is indeed the case for every norm or quasi-norm $\ell_p$, even if they tend to the (non-robust) count measure $\ell_0$ as $p\to 0$.
So they detail their six axioms, performed computations, borrowed from wealth analysis:
Robin Hood (take from the rich, give to the poor reduces sparsity),
Scaling (constant multiplication preserves sparsity),
Rising Tide (adding the same non zero account reduces sparsity),
Cloning (duplicating data preserves sparsity),
Bill Gates (One man getting richer increases sparsity),
Babies (adding zero values increases sparsity)
and probe known measures against them, revealing that the Gini index and some norm or quasi-norm ratios could be good candidates (for the latter, some details are provided in Euclid in a Taxicab: Sparse Blind Deconvolution with Smoothed $\ell_1/\ell_2$ Regularization, 2005, IEEE Signal Processing Letters). I sense that this initial work ought to be further developed (stay tune at SPOQ, Smoothed $p$ over $q$ $\ell_p/\ell_q$ quasi-norms/norms ratios). Because for a signal $x$, $0< p\le q$, the norm ratio inequality yields:
$$ 1\le \frac{\ell_p(x)}{\ell_q(x)}\le \ell_0(x)^{1/p-1/q}$$
and tends to $1$ (left-hand side, LHS) when $x$ is sparse, and to the right-hand side (RHS) when not. This work is now a preprint: SPOQ: smooth p-Over-q Regularization for Sparse Signal Recovery applied to Mass Spectrometry.
However, a sound measure of sparsity does not tell you whether the transformed data is sufficiently sparse, or not, for your purpose.
Finally, another concept used in compressive sensing is that of the compressibility of signals, where the re-ordered (descending order) coefficient magnitudes $c_{(k)}$ follow a power law $C_\alpha .(k)^{-\alpha}$, and the bigger the $\alpha$, the sharper the decay.
|
Groom abandons bride at RCCG church for being pregnant
On Saturday, 22nd February, a groom called off his wedding after the Redeemed Christian Church of God RCCG that was supposed to wed them conducted a pregnancy test and it came out positive.
After keeping guests waiting for about two hours the groom came out and announced to the astonished guests that he was no longer interested in the marriage.The bride, Cynthia who insisted she was not pregnant did another pregnancy test in a different hospital which came out negative. The church did a second test with their own doctor and again their own test came out positive again.The groom said he had never slept with the girl hence he couldn’t go on with the wedding.Despite the wedding being called off, guests still sat down to eat and drink and even pack souvenirs.To make things even more interesting, the groom’s family went on to pack the wedding cake, wine and other drinks as well as souvenirs even though those things were paid for by the bride’s family.All this time the poor bride, still in her wedding gown kept crying and insisting she wasn’t pregnant. |
The corvette is among the smallest naval class vessel to be deployed on the Dystopian seas. Stripped down to the bare essentials they are small and agile allowing superior tacticians to effectively use them to speed into battle, whether it be to initiate a swift first strike or to distract enemy fire!
Federated States of America - Revere Class Corvette
The Federated States of America initially scrapped their plans for such a small fighting ship. It was decided that the resources required to produce a steam vessel with such an undersized presence amongst a fleet could be better spent elsewhere. However, after reviewing a design by a relatively unknown engineer who’s inspired patriotism had lead him and a small team to create a small, easy to produce steam vessel that did not require a dockyard to build the FSA gave the go-ahead for the corvette.
Kingdom of Britannia - Swift Class Corvette
The Britannian Corvette’s initial design was that of a short range scouting vessel. After earning its stripes in a number of sorties and rescue missions however the ship’s build profile was upgraded to accommodate a fore turret and improved armour surrounding the magazine which is positioned directly below the gun itself. Some distinct features remain however, such as the starboard searchlight and more civilian looking cabin.
Prussian Empire - Saxony Class Corvette
The Prussian Corvette was designed from the very beginning to be an effective small fighter. Additional armour was later added to the bow but other than that its profile is identical to that of the blue-prints that gave birth to it. It is a welcome sight for crews of Prussian fleet ships immersed in the heat of battle as it races alongside to support its fellow naval vessels.
Empire of the Blazing - Fujin Class Corvette
The Blazing Sun Corvette is a prototype vessel that comes with an unfortunate reputation of being unstable as a fighting ship. Additional armour and shielding were added to the bow to deflect fire away from the exposed front and mid-section which proved to have plating too thin to stand up to incoming projectiles designed for penetration. It is not unknown for these vessels to be seen exploding on the distant horizon. Their crews however remain ever loyal to their cause. The ship’s saving grace is its ease to manufacture and the shear speeds that can be achieved by the vessel once it has built up some momentum!
Covenant of Antarctica - Thales Class Corvette
The Thales was a continuation of the design presented by the Diogenes Frigate, a ship built with aesthetics more in mind that practicality. The inventors and scientists of the Covenant of Antarctica, lacking the utilitarian push of a unified military doctrine give their vessels character first and practicality second. This approach did give rise to the nature mimicking small vessels and the speed boost provided by their streamlined shape. The Thales is a prime example of this, with its weapon housed in its swept back brackets, it retains the deadly speed of its counterparts by sacrificing the versatility of its main weapon. This reduced the Thales to a niche role in fast attack and patrol, but it was a welcome addition to the waters surrounding the Antarctican continent. |
Q:
16 million goroutines - "GC assist wait"
I'm running a go program that computes the mandelbrot set. A gouroutine is started for every pixel to compute convergence. The program runs fine for pixelLengthx = 1000, pixelLengthy = 1000.
If I run the same code for pixelLengthx = 4000, pixelLengthy = 4000, the program starts printing this after a few dozen seconds:
goroutine 650935 [GC assist wait]:
main.converges(0xa2, 0xb6e, 0xc04200c680)
.../fractals/fractals.go:41 +0x17e
created by main.main
.../fractals/fractals.go:52 +0x2af
The program does not terminate and just continues printing.
package main
import (
"image"
"image/color"
"image/draw"
"image/png"
"log"
"math/cmplx"
"os"
"sync"
)
var sidex float64 = 4.0
var sidey float64 = 4.0
var pixelLengthx int = 4000
var pixelLengthy int = 4000
var numSteps int = 100
func converges(wg *sync.WaitGroup, i, j int, m *image.RGBA) {
wht := color.RGBA{255, 50, 128, 255}
plx := float64(pixelLengthx)
ply := float64(pixelLengthy)
fi := float64(i)
fj := float64(j)
c := complex((fi-plx/2)/plx*sidex, (fj-ply/2)/ply*sidey)
zn := complex(0, 0)
for k := 0; k < numSteps; k++ {
zn = cmplx.Pow(zn, 2) + c
}
if cmplx.Abs(zn) > 0.1 {
m.Set(i, j, wht)
}
wg.Done()
}
func main() {
err := Main()
if err != nil {
log.Fatal(err)
}
}
func Main() error {
m := image.NewRGBA(image.Rect(0, 0, pixelLengthx, pixelLengthy))
blk := color.RGBA{0, 0, 0, 255}
draw.Draw(m, m.Bounds(), &image.Uniform{blk}, image.ZP, draw.Src)
numGoroutines := pixelLengthx * pixelLengthy
wg := &sync.WaitGroup{}
wg.Add(numGoroutines)
for x := 0; x < pixelLengthx; x++ {
for y := 0; y < pixelLengthy; y++ {
go converges(wg, x, y, m)
}
}
wg.Wait()
f, err := os.Create("img.png")
if err != nil {
return err
}
defer f.Close()
err = png.Encode(f, m)
if err != nil {
return err
}
return nil
}
What is going on here? Why does the program even print something?
I'm using go version go1.8 windows/amd64.
Memory usage during program execution.
A:
goroutine is lightweight but you have too much overconfident. You should make worker like below, I think.
package main
import (
"image"
"image/color"
"image/draw"
"image/png"
"log"
"math/cmplx"
"os"
"sync"
)
var sidex float64 = 4.0
var sidey float64 = 4.0
var pixelLengthx int = 4000
var pixelLengthy int = 4000
var numSteps int = 100
func main() {
err := Main()
if err != nil {
log.Fatal(err)
}
}
type req struct {
x int
y int
m *image.RGBA
}
func converges(wg *sync.WaitGroup, q chan *req) {
defer wg.Done()
wht := color.RGBA{255, 50, 128, 255}
plx := float64(pixelLengthx)
ply := float64(pixelLengthy)
for r := range q {
fi := float64(r.x)
fj := float64(r.x)
c := complex((fi-plx/2)/plx*sidex, (fj-ply/2)/ply*sidey)
zn := complex(0, 0)
for k := 0; k < numSteps; k++ {
zn = cmplx.Pow(zn, 2) + c
}
if cmplx.Abs(zn) > 0.1 {
r.m.Set(r.x, r.y, wht)
}
}
}
const numWorker = 10
func Main() error {
q := make(chan *req, numWorker)
var wg sync.WaitGroup
wg.Add(numWorker)
for i := 0; i < numWorker; i++ {
go converges(&wg, q)
}
m := image.NewRGBA(image.Rect(0, 0, pixelLengthx, pixelLengthy))
blk := color.RGBA{0, 0, 0, 255}
draw.Draw(m, m.Bounds(), &image.Uniform{blk}, image.ZP, draw.Src)
for x := 0; x < pixelLengthx; x++ {
for y := 0; y < pixelLengthy; y++ {
q <- &req{x: x, y: y, m: m}
}
}
close(q)
wg.Wait()
f, err := os.Create("img.png")
if err != nil {
return err
}
defer f.Close()
err = png.Encode(f, m)
if err != nil {
return err
}
return nil
}
|
2 + 7249770*x - 14499513/2.
-(x - 537019)*(x - 3)**3/2
Determine x so that -64*x**5 - 412816*x**4 - 871942924*x**3 - 568285601147*x**2 + 73515560267758*x - 72946402310807 = 0.
-8747/4, 1, 109
Factor j**2/3 + 1639700*j/3 + 1639699/3.
(j + 1)*(j + 1639699)/3
Solve 4*k**5 - 210184*k**4 + 2740154676*k**3 + 550907069056*k**2 - 1120991017408*k - 1669157721600 = 0.
-200, -1, 3, 26372
Find p such that 3*p**2/5 - 6345927*p/5 + 12691842/5 = 0.
2, 2115307
Factor -3*p**3/2 + 3591*p**2/2 - 440793*p/2 + 14315421/2.
-3*(p - 1063)*(p - 67)**2/2
Let -i**5/7 + 1241*i**4/7 + 234930*i**3/7 + 2234000*i**2 + 453872000*i/7 + 4890240000/7 = 0. Calculate i.
-54, -40, 1415
Suppose -o**4/7 - 13347*o**3/7 + 334157*o**2/7 - 273195*o - 2259868/7 = 0. What is o?
-13372, -1, 13
Let -4*i**4 + 18916*i**3 - 21050268*i**2 - 3154650356*i + 12954196112 = 0. Calculate i.
-137, 4, 2431
Determine b so that -2*b**5/13 - 1050*b**4/13 - 21358*b**3/13 - 95910*b**2/13 - 75600*b/13 = 0.
-504, -15, -5, -1, 0
Factor 213*a**2 - 59697*a/4 + 1995/2.
3*(a - 70)*(284*a - 19)/4
Factor j**2/4 + 90951*j/4 - 18407831/2.
(j - 403)*(j + 91354)/4
What is z in -4*z**5 + 4996*z**4 - 170576*z**3 + 748304*z**2 - 582720*z = 0?
0, 1, 4, 30, 1214
Factor -2*m**2/5 + 71551264*m/5 - 639947922499712/5.
-2*(m - 17887816)**2/5
Factor -s**3/2 - 776170*s**2 + 7761725*s/2.
-s*(s - 5)*(s + 1552345)/2
Suppose r**4/5 + 4944*r**3/5 + 5580334*r**2/5 - 262254480*r + 14068860125 = 0. Calculate r.
-2575, 103
Solve 6*m**2 - 2062367*m/4 - 21483 = 0 for m.
-1/24, 85932
What is r in r**2/2 + 39685*r + 15401100 = 0?
-78980, -390
Factor 2*x**2 + 814*x - 1460700.
2*(x - 675)*(x + 1082)
Determine z, given that 4*z**2 - 1455548*z + 4366608 = 0.
3, 363884
Factor -25*y**2/6 + 157837280*y/3 - 498252139155968/3.
-(5*y - 31567456)**2/6
Factor -6*w**2/11 - 927516*w - 394297718034.
-6*(w + 850223)**2/11
Solve t**2/7 + 7718*t/7 - 1599840/7 = 0 for t.
-7920, 202
Solve -4*z**5 - 944*z**4 + 81440*z**3 - 2162432*z**2 + 22792640*z - 83283200 = 0.
-308, 10, 26
Solve -4*p**3 + 134379608*p**2 - 1128617440389604*p = 0 for p.
0, 16797451
Factor p**3/2 - 88*p**2 - 86437*p/2 + 1694230.
(p - 380)*(p - 37)*(p + 241)/2
Let -18*z**5 + 411*z**4 - 2979*z**3 + 5616*z**2 + 9024*z = 0. Calculate z.
-1, 0, 47/6, 8
Let -5*h**2 - 13328590*h + 13328595 = 0. Calculate h.
-2665719, 1
Solve 5*l**3 - 34324865*l**2 - 205949325*l - 308924055 = 0.
-3, 6864979
Find u such that 2*u**2/15 + 125302246*u/15 - 41767416/5 = 0.
-62651124, 1
Factor -2*w**2 + 3402*w + 693680.
-2*(w - 1885)*(w + 184)
What is p in -p**2/2 + 2002*p - 1802779/2 = 0?
517, 3487
What is n in -n**5 - 16071*n**4 + 241744*n**3 + 7295448*n**2 - 122182128*n + 114661008 = 0?
-16086, -22, 1, 18
Find j, given that j**2 + 11238458*j - 11238459 = 0.
-11238459, 1
Factor s**2 + 715444*s.
s*(s + 715444)
Let -50*n**2 - 38344*n + 4602 = 0. Calculate n.
-767, 3/25
Factor 3*a**4/5 + 367824*a**3/5 + 3015707904*a**2 + 208531797298176*a/5 + 76295704778084352/5.
3*(a + 376)*(a + 40744)**3/5
Determine a so that -2*a**4/5 - 602*a**3/5 - 39284*a**2/5 - 76176*a/5 = 0.
-207, -92, -2, 0
Suppose -2*s**2/3 + 40342*s/3 - 73910108/3 = 0. What is s?
2038, 18133
Solve 3*p**3/5 + 33264*p**2/5 + 33261*p/5 = 0.
-11087, -1, 0
Find c, given that -c**4/4 + 4605*c**3/4 + 581545*c**2/4 - 4605*c/4 - 145386 = 0.
-123, -1, 1, 4728
Factor h**3/4 - 102641329*h**2/4 + 2633810553400895*h/4 + 2633810656042225/4.
(h - 51320665)**2*(h + 1)/4
Factor -v**3/4 + 987*v**2/2 - 92871*v + 4603770.
-(v - 1770)*(v - 102)**2/4
Determine g so that -2*g**3/3 - 27994*g**2/3 + 18149536*g - 8291803008 = 0.
-15773, 888
Solve -t**3 + 3587*t**2 - 187248*t - 190836 = 0 for t.
-1, 54, 3534
Determine r so that -2037296*r**2 - 2037412*r - 116 = 0.
-1, -29/509324
Let -2*c**5 + 296050*c**4 - 1184170*c**3 + 296030*c**2 + 1776252*c = 0. Calculate c.
-1, 0, 2, 3, 148021
Solve -n**3/9 + 10420*n**2 + 1250800*n/3 + 37528000/9 = 0 for n.
-20, 93820
Let z**4 + 3169*z**3 + 2585674*z**2 + 116731680*z - 1961481600 = 0. What is z?
-1560, -62, 13
Find g, given that -2*g**4/9 + 180320*g**3/9 - 4074138416*g**2/9 + 48714529920*g - 1313716758048 = 0.
54, 45026
Factor -10*f**2 + 162848*f + 18727658.
-2*(f - 16399)*(5*f + 571)
Determine o, given that o**2 - 20035444*o - 20035445 = 0.
-1, 20035445
Factor w**2 + 12349*w - 1773722.
(w - 142)*(w + 12491)
Find j, given that 185*j**2 - 6970*j - 33600 = 0.
-160/37, 42
Let -w**2 - 530*w - 59200 = 0. Calculate w.
-370, -160
What is i in 2*i**2 - 88105152*i + 970314726117888 = 0?
22026288
Find q such that 3*q**3 + 5615777*q**2 + 11231551*q/3 + 623975 = 0.
-1871925, -1/3
Find p, given that -2*p**3 + 2044*p**2 + 208278*p + 1707480 = 0.
-85, -9, 1116
Solve 2*b**4/7 + 334*b**3/7 + 15500*b**2/7 + 181056*b/7 + 165888/7 = 0 for b.
-96, -54, -16, -1
What is l in -l**3 - 35790927*l**2 - 71581851*l - 35790925 = 0?
-35790925, -1
Factor 2*v**2/3 + 625364*v + 7504336/3.
2*(v + 4)*(v + 938042)/3
Suppose t**4/2 + 1117*t**3 + 1319233*t**2/2 + 39957324*t + 639817992 = 0. What is t?
-1084, -33
Factor -m**4 + 837*m**3 - 2504*m**2 + 1668*m.
-m*(m - 834)*(m - 2)*(m - 1)
Suppose -88*r**2 + 203196*r/5 + 38808/5 = 0. What is r?
-21/110, 462
Factor -n**3/2 - 733*n**2/2 - 75240*n - 2865618.
-(n + 49)*(n + 342)**2/2
Find w, given that 2*w**4/5 + 18*w**3/5 - 1230*w**2 + 12134*w/5 + 3660 = 0.
-61, -1, 3, 50
Determine u, given that -25*u**5 + 37590*u**4 - 13390110*u**3 - 556164460*u**2 - 5585150985*u - 2145932010 = 0.
-19, -2/5, 771
Solve u**3 - 118920*u**2 + 3534421077*u + 63658115298 = 0.
-18, 59469
Solve 2*n**4 - 2146374*n**3 - 6439134*n**2 - 6439138*n - 2146380 = 0 for n.
-1, 1073190
Solve -5*b**2 + 45050*b - 24014645 = 0 for b.
569, 8441
What is w in w**5/3 + 185*w**4 - 5128*w**3/3 - 9776*w**2 = 0?
-564, -4, 0, 13
Determine b, given that 35*b**5 + 16755*b**4 - 660025*b**3 - 3045915*b**2 + 16064750*b - 4326000 = 0.
-515, -7, 2/7, 3, 40
Factor 12*a**3 - 2565*a**2 + 14397*a - 9360.
3*(a - 208)*(a - 5)*(4*a - 3)
Find r such that -2*r**2/3 - 28576*r/3 + 61550578/3 = 0.
-16189, 1901
Factor 4*x**2 - 1525664*x + 3051312.
4*(x - 381414)*(x - 2)
Factor k**2/2 - 8660691*k/2 - 4330346.
(k - 8660692)*(k + 1)/2
What is y in -7*y**5/6 - 124135*y**4/6 - 275094197*y**3/3 + 223000628*y**2 + 812415216*y - 943697088 = 0?
-8868, -18/7, 1, 4
Suppose -204*c**2 + 48370*c/3 - 1738/3 = 0. Calculate c.
11/306, 79
Factor -4*y**2 - 1645088*y - 6580288.
-4*(y + 4)*(y + 411268)
What is t in -4*t**5 + 293652*t**4 - 7045816*t**3 + 34638360*t**2 + 91588796*t + 49610964 = 0?
-1, 13, 73389
Determine l so that l**3/8 - 34499*l**2/8 - 69037*l/8 + 1207535/8 = 0.
-7, 5, 34501
Let a**5/2 - 2309*a**4/2 + 661221*a**3 + 6018115*a**2 + 30860693*a/2 + 20149215/2 = 0. Calculate a.
-5, -3, -1, 1159
Factor -2*k**2 + 850220*k + 57824208.
-2*(k - 425178)*(k + 68)
What is s in 2*s**5 + 45000*s**4 - 900664*s**3 + 3062592*s**2 - 2882560*s = 0?
-22520, 0, 2, 16
Determine n, given that -n**2/4 - 162116*n - 1296912 = 0.
-648456, -8
Find n, given that 3*n**2/7 - 167868*n/7 - 27779895/7 = 0.
-165, 56121
Let -2*i**3/15 - 585814*i**2/15 + 2460604*i/3 + 12888832/15 = 0. Calculate i.
-292928, -1, 22
Solve 7*j**5/2 + 1513927*j**4/2 + 81854193931*j**3/2 - 222194176559*j**2/2 - 198799601569*j - 46776173284 = 0 for j.
-108139, -1, -2/7, 4
Solve -27*z**5 + 921*z**4 + 2463*z**3 - 21021*z**2 - 56016*z + 6480 = 0.
-4, -3, 1/9, 5, 36
Suppose -3*m**4/5 - 1922007*m**3/5 - 82137174147*m**2 - 29316372962199477*m/5 - 10442714514146142522/5 = 0. Calculate m.
-213437, -358
Determine l so that -4*l**5 - 14292*l**4 - 1920196*l**3 + 7838100*l**2 - 9858424*l + 3954816 = 0.
-3433, -144, 1, 2
Solve 195*r**4 + 4482*r**3 + 10851*r**2 - 15768*r + 240 = 0 for r.
-20, -4, 1/65, 1
Suppose -2*y**3/5 + 280732*y**2/5 + 786134*y - 842280 = 0. Calculate y.
-15, 1, 140380
Suppose -4*x**2 + 19080*x - 14458500 = 0. What is x?
945, 3825
Solve -x**4/2 + 71515*x**3/2 - 2501867*x**2/2 + 4789193*x/2 - 1179420 = 0 for x.
1, 33, 71480
Factor f**3/2 - 537*f**2 - 28435*f/2 - 90750.
(f - 1100)*(f + 11)*(f + 15)/2
Factor -5*x**2/3 - 29967070*x - 134703792657735.
-5*(x + 8990121)**2/3
Factor 5*h**3 + 2075*h**2 - 257005*h + 254925.
5*(h - 99)*(h - 1)*(h + 515)
Find c such that 12927*c**5 + 206814*c**4 + 1020945*c**3 + 2015190*c**2 + 1393308*c - 1944 = 0.
-9, -3, -2, 6/4309
Let 147*m**3 - 57 |
Guangzhou again ranked first in "Rule of Law" Evaluation
The Research Center of Government by Law at the China University of Political Science and Law released the Report on the Evaluation of Chinese Governments by Law (2014) recently.
The Research Center of Government by Law at the China University of Political Science and Law released the Report on the Evaluation of Chinese Governments by Law (2014) recently. Of the 100 evaluated cities, Guangzhou ranked first, followed by Beijing and Foshan.
Foshan ranked 3rd
The Center began an annual evaluation of government by law in 2013 and released its first evaluation report at the end of last year. In that report, the Guangzhou municipal government scored 234.93 points, 46.06 points higher than the national average and the highest among the 53 evaluated large cities in China.
This year's evaluation report shows that Guangzhou has the highest score among the 100 evaluated cities.
In November 21, 2013, Guangzhou officials put 387 items of administrative examination and approval powers and 3,138 items of administrative punishment powers on the website of the Guangzhou municipal government for public scrutiny, becoming the first city in China to show a list of administrative powers. Guangzhou officials have carried out five rounds of reforms of the city's administrative examination and approval system, abolishing more than 2,700 matters requiring administrative approval. |
Chocolate Velvet staff cars prevent the Chorus van from leaving on Thursday April 14 after a week without a phone connection.
A Nelson couple left without a phone connection for more than a week after getting fibre installed say it has cost their business thousands of dollars.
The couple were so frustrated at the lack of action after a week without a phone they boxed in a Chorus vehicle for five hours, demanding technicians reconnect the line.
Cake company Chocolate Velvet owners Phil and Leanne Lash said their main issue was with the lack of communication from their landline provider Spark.
ALDEN WILLIAMS/FAIRFAX NZ Chocolate Velvet owner operator Phil Lash is battling Spark and Chorus to fix his company's landline which has been out of action for over a week.
They had no answer from Spark about why their phone was not working during the eight days without it.
READ MORE:
* Spark: Officially NZ's most complained about company
* Geraldine man left without a phone line for months
* Spark's poor service drives man to brink
"I think it would have been one of the most stressful experiences I have been through in my 10 years of being in business," Leanne said.
About 70 per cent of their business came via their landline with people calling up to place orders.
The disruption cost them several thousand dollars worth of business. Cake sales were down during their time without a landline - a direct result of customers not being able to reach them, Phil said.
It is not the first time trouble with phone and internet connections after fibre installation have made the headlines. In February, a Geraldine man spent more than two months waiting for his landline and broadband to be connected.
After spending almost two weeks without internet or phone in November, a Hamilton man advertised for Spark therapy in a local paper.
Fibre was installed at Chocolate Velvet on April 7 and the following day, they realised that somewhere in the process their landline had stopped working.
The first Leanne knew of the issue was when a customer came into the shop and said they had left a message about collecting a cake. She wondered why she had not heard the phone ring.
They spent several hours on the phone trying to get through to Spark over the week to resolve the issue without success.
A call diversion was put in place so calls were diverted to the couple's cellphones but that only worked for two days and they could not get hold of anyone at Spark to reinstate it.
Chorus said the landline not working was the service provider Spark's problem. Spark said it was a Chorus problem as it had occurred after the fibre installation.
"It feels like there is no-one to contact. Who does anyone contact if there is an issue with their phone line? I'm sure we are not the only ones who have been through this," Leanne said.
A Chorus employee who came out on April 9 said that the fibre hadn't been installed correctly and technicians would need to return to fix it.
When they returned on April 14, after a week without the their landline, Phil said he was at the end of his tether.
He told them they were not leaving until their phone was reconnected.
"We gave them cups of coffee and pieces of cake to eat, they were quite happy," Leanne said.
The technicians spent two and a half hours on hold with Spark before Phil got a call at 7.30pm from their manager asking if they could go home.
Leanne said the biggest problem was that Chorus appeared to have no direct contact with Spark and had to use the same channels to contact them that anyone else would.
"I think that Chorus really did a good job trying to help us, but Spark is our provider and they did nothing for us," she said.
The landline was reconnected late the next day on April 15.
"From our point of view, why can't the provider ring the customer with a solution, or an answer or a timeframe of when it is going to be fixed?"
The couple, who have been with Telecom, then Spark since their they started their business 12 years ago and after the experience are considering changing providers.
Chorus media and PR manager Nathan Beaumont said when a customer requested fibre installation, the internet service provider would contact Chorus to place an order on their behalf.
He said Chorus connected ultra fast broadband at Chocolate Velvet on April 7 and they were informed by Spark they would manage the set up of the phone service. As the phone service was provided by Spark, they were the point of contact if there was an outage.
A spokeswoman for Spark said as part of the fibre installation for Chocolate Velvet, the landline was moved to the voice-over-fibre service but there was some difficulty getting it to work.
"We're extremely sorry for the poor experience Phil and Leanne have had and for the time it's taken Spark to resolve this issue," she said.
"We know it's incredibly frustrating for customers when they're trying to run a business and so we're currently reviewing our processes to get to the root cause of the issue and to understand why it took so long to fix it."
* Comments on this article have now closed. |
Oakland Raiders' running back Darren McFadden walking better
ALAMEDA -- Raiders running back Darren McFadden was moving well and walking without a limp Wednesday as he left the team facility and headed to his car in the parking lot, with a couple fans outside the security gate calling his name.
McFadden still was wearing a walking boot on his right foot, however, and coach Dennis Allen didn't sound overly optimistic, saying McFadden was "questionable" to face the New Orleans Saints on Sunday at O.co Coliseum.
The same goes for running back Mike Goodson, who like McFadden has a high right ankle sprain, and defensive tackle Richard Seymour, who was a spectator at practice because of a hamstring strain.
Seymour offered a friendly smile and volunteered, "I will say this -- I feel great, except for my hamstring."
Allen said in the absence of McFadden, Goodson and Seymour, the rotations would be similar to what they were in Sunday's 55-20 loss to Baltimore. Marcel Reece would be the lead back, with Jeremy Stewart getting work and Taiwan Jones getting a shot if he continues to show progress in the areas of ball security, general health and ability to execute the playbook.
Also missing practice were strong safety and leading tackler Tyvon Branch, out with a sore neck, and free safety Matt Giordano, currently undergoing the NFL concussion protocol.
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If either man -- or both -- couldn't play, it would cause another reshuffling of the secondary that could include moving cornerback Michael Huff back to free safety and starting Mike Mitchell at strong safety.
Joselio Hanson would be the likely candidate to start alongside Ron Bartell at cornerback, while Phillip Adams, Brandian Ross and Coye Francies are all available but primarily special teams players.
As for how the Raiders will adjust if necessary, Allen said, "We'll kind of keep that under our hats until this weekend."
New Orleans interim coach Joe Vitt relayed a story by conference call about a conversation he had with Al Davis as a 26-year-old assistant looking for work at the 1981 NFL scouting combine.
Vitt proudly rattled off his résumé -- three years in the NFL with the Baltimore Colts as a strength coach, a quality control coach, even passing out tickets in the plane.
"He looked me in the eye and said, 'Son, when I was 26 years old, I was commissioner of the AFL,' " Vitt said. "I crawled out of the locker room. He never forgot that, and I never forgot that."
A great story ... although a bit of an exaggeration on Davis' part. He wasn't the AFL commissioner until he was 34.
Linebacker Omar Gaither, who has played in 77 games with 40 starts over six seasons with Philadelphia and Carolina, was signed to the 53-man roster. He replaces Travis Goethel, who was placed on injured reserve with a torn ACL.
Tight end Brandon Myers, listed with a concussion after the Baltimore game, was cleared to play, according to Allen. Myers said he didn't have a concussion. |
Saturday, October 20, 2012
• •Nat Geo denies ‘SEAL Team Six’ film is timed to affect vote, Atlas Shrugged movie|Atlas Shrugged|Capitalism|Harmon Kaslow, the producer of the forthcoming “Atlas Shrugged: Part II,” has been fairly straightforward in acknowledging that the pro-capitalist movie sequel’s Oct. 12 release date, just weeks before Election Day, is intentional. Having part two of the cinematic adaptation of Ayn Rand’s classic novel — the first installment flopped big time last year — in theaters “will give like-minded people an opportunity to get together and sort of discuss the issues, and the course of action that they’re going to take in connection with those elections,” Mr. Kaslow told The Washington Times earlier this year.View blog reactions |
Drew Cline: Bob Smith's three 'p's': Principle, platform, party
DREW CLINEJuly 16. 2014 10:51PMWHEN BOB SMITH renounced his membership in the Republican Party in a famous speech on the floor of the U.S. Senate on July 13, 1999, he uttered the word “principle” 15 times, “platform” 25 times and “party” 78 times. In an interview with this newspaper exactly 15 years and two days after that speech, Smith obsessively reworked the same theme: The Republican Party is full of sellouts and moderates who don’t uphold the platform and don’t care about principles; and Bob Smith is the one to set things right.
“I have come to the cold realization that the Republican Party is more interested in winning elections than supporting the principles of the platform,” Smith said in 1999.
On Wednesday, Smith said “the national Republicans, and by that I mean the RNC and the Senate committee, have made it very clear who they want” to win the primary. But their favored candidate, Scott Brown, does not support the party platform, Smith said. With Brown, “the only thing we get is a vote against Harry Reid ... If you want to win, then win on principle.”
Smith repeats often that Brown voted with the Democrats more than half the time. But as I wrote last week, The Washington Post’s vote analysis shows that Brown voted with Republicans 81 percent of the time in the 111th Congress and 61 percent of the time in the 112th. Smith needs Republicans to believe that Brown is not really one of them. It is the only hope for a candidate who denounced the party 15 years ago, moved out of state 11 years ago, and endorsed John Kerry 10 years ago.
About the Kerry endorsement, which Smith made in a personal letter to Kerry, who then made the letter public, Smith says it was “a terrible, stupid mistake.” His motivation? “I got angry.”
In 2002, Karl Rove promised him a presidential endorsement in the primary if John E. Sununu entered the race, Smith said. Sununu got in, the endorsement never came, and Smith lost. His letter to Kerry was “a get even thing,” he said. He nursed a personal grudge for two years, just waiting for the chance to get his revenge. This is one elephant that never forgets.
Still, “I did not vote for him” (Kerry), Smith said. Reminded that he wrote in his letter that every member of his family planned to vote for Kerry, Smith said “there may have been some in my family who did, but it wasn’t me.”
Smith’s lofty talk of principle has always burned with resentment. The commitment to ideals is real, not contrived. But it always has contained the wounded tone of the smart kid shouting from the back of the high school chess club meeting that the vote for club president was just a popularity contest.
Successful politicians tend to accumulate friends and allies over the decades. Smith sheds them. In his 1999 speech, he denounced then-state Republican Party Chairman Steve Duprey by name. In 2004 he earned the permanent enmity of Bushworld by endorsing Kerry. In his current campaign, he speaks dismissively of his primary rivals Brown and Jim Rubens (naturally), and also the Sununus, current state party chairman Jennifer Horn, the Republican National Committee, the National Republican Senatorial Committee, even Sen. Kelly Ayotte, with whom he hopes to work.
Speaking of Republicans who cannot be trusted to uphold the platform, he said “I don’t think that Ayotte’s quite in that category. But she’s getting there.”
For Bob Smith, there can be no deviation from the platform, which he equates with principle. He said he is the “only platform Republican,” the “only constitutional conservative,” the “best pro-gun candidate” and “the only pro-life candidate” in the race. Check the boxes, and Bob Smith will have the most checks. That’s what should matter. Principle. Platform. Party.
Bob Smith’s checklist leaves out one “p,” and it is one voters value very highly. Personality. It is sometimes used interchangeably with another p-word: popularity.
Politics might be about principles, but elections are about popularity. Smith says that if he is elected, he will join Sens. Ted Cruz and Mike Lee, two men he considers principled conservatives, to champion true Republicanism in the U.S. Senate. Reminded that the two could hold their meetings in a closet, he said he has already spoken with them and told them that if he gets there “I can help you build a bigger closet.”
Smith says that when he was young, he aspired to one of only three careers: a Major League Baseball player, a U.S. senator or a country music singer. He couldn’t sing, and he was not good enough at baseball to play past high school. That left politics. Smith was good at that, and he has the resume to prove it.
“I won 11 elections,” he said. But his last win was 18 years ago. New Hampshire has changed a lot since then. Bob Smith has not.
Andrew Cline is editorial page editor of the New Hampshire Union Leader. His column runs on Thursdays. You can follow him on Twitter @Drewhampshire. |
Emergency department-based intervention with adolescent substance users: 12-month outcomes.
We evaluated the 12-month outcomes of a brief intervention, enhanced by a consistent support person, which aimed to facilitate referral attendance for substance use treatment following a hospital alcohol or other drug (AOD) presentation. Outcomes were assessed as: attendance for substance use treatment; the number of hospital AOD ED presentations; change in AOD consumption and psychological wellbeing (GHQ-12). We recruited 127 adolescents, with 60 randomised to the intervention and 67 receiving usual care. At 12 months, 87 (69%) were re-interviewed. Significantly more of the intervention than the usual care group (12 versus 4) had attended a treatment agency. Excluding the index presentations, there were 66 AOD hospital presentations post intervention, with the proportion of AOD events falling for the intervention group, whilst no change occurred for the usual care group. Irrespective of randomisation, those who attended for substance use treatment had a greater decline in total self-reported drug use than the remainder. Both intervention and usual care groups had improved GHQ-12 scores by 12 months, with reduction in GHQ scores correlated with reduced drug use. In conclusion, while brief intervention in ED only has limited success in facilitating adolescents to attend for subsequent AOD treatment, it can significantly reduce the number of AOD related ED presentations. |
Currently, a telephone company/carrier-billed mobile customer can purchase a connected mobile device from a telephone/carrier wireless network operator, such as AT&T®, VERIZON®, or T-MOBILE®, with payment functionality, but that payment functionality is very limited. For example, a customer is typically able to make only low-value payments in a range of $30 or less per month. Further, the selection is generally limited, for example, to the purchase of digital goods, such as ring tones, music, apps, and video, which is funded through the monthly telephone/carrier monthly statement. There is a present need to extend the current telephone company billing model and to enable full customer payment capability. |
1979 Georgia Bulldogs football team
The 1979 Georgia Bulldogs football team represented the Georgia Bulldogs of the University of Georgia during the 1979 NCAA Division I-A football season.
Schedule
Roster
Game summaries
LSU
Scott Woerner recovered a fumble with just over two minutes remaining with LSU driving at the Georgia 22 to seal the upset.
References
Georgia
Category:Georgia Bulldogs football seasons
Bulldogs football |
/**
* Copyright (c) 2000-present Liferay, Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*/
package com.liferay.ide.ui.workspace;
import com.liferay.ide.core.util.FileUtil;
import com.liferay.ide.ui.dialog.ChooseWorkspaceWithPreferenceDialog;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.osgi.service.datalocation.Location;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.internal.ide.ChooseWorkspaceData;
import org.eclipse.ui.internal.ide.ChooseWorkspaceDialog;
/**
* @author Kamesh Sampath
* @author Gregory Amerson
*/
@SuppressWarnings("restriction")
public class LaunchWorkspaceHandler extends AbstractHandler {
public static final String COMMAND_ID = "com.liferay.ide.ui.workspace.launchWorkspace";
public static final String PARAM_LIFERAY_7_SDK_DIR = "liferay7SDKDir";
public static final String PARAM_WORKSPACE_LOCATION = "workspaceLocation";
@Override
public Object execute(ExecutionEvent event) throws ExecutionException {
String workspaceLocation = event.getParameter(PARAM_WORKSPACE_LOCATION);
Location installLocation = Platform.getInstallLocation();
if (workspaceLocation == null) {
ChooseWorkspaceData chooseWorkspaceData = new ChooseWorkspaceData(installLocation.getURL());
Display display = Display.getDefault();
ChooseWorkspaceDialog chooseWorkspaceDialog = new ChooseWorkspaceWithPreferenceDialog(
display.getActiveShell(), chooseWorkspaceData, true, true);
if (chooseWorkspaceDialog.open() == IDialogConstants.OK_ID) {
workspaceLocation = chooseWorkspaceData.getSelection();
}
else {
return null;
}
}
String liferay7SDKDir = event.getParameter(PARAM_LIFERAY_7_SDK_DIR);
List<String> commands = new ArrayList<>();
File launchDir = FileUtil.getFile(installLocation.getURL());
File launcher;
if (launchDir.exists()) {
switch (Platform.getOS()) {
case Platform.OS_MACOSX:
File parentFile = launchDir.getParentFile();
launcher = parentFile.getParentFile();
break;
default:
launcher = new File(System.getProperty("eclipse.launcher"));
}
}
else {
launcher = null;
}
if ((launcher != null) && launcher.exists()) {
switch (Platform.getOS()) {
case Platform.OS_MACOSX:
commands.add("open");
commands.add("-n");
commands.add(launcher.getAbsolutePath());
commands.add("--args");
commands.add("-data");
commands.add(workspaceLocation);
break;
case Platform.OS_LINUX:
commands.add("/bin/bash");
commands.add("-c");
commands.add("''./" + launcher.getName() + " -data \"" + workspaceLocation + "\"''");
break;
case Platform.OS_WIN32:
commands.add("cmd");
commands.add("/c");
commands.add(launcher.getName());
commands.add("-data");
commands.add(workspaceLocation);
break;
}
if (liferay7SDKDir != null) {
commands.add("-vmargs");
commands.add("-Dliferay7.sdk.dir=\"" + liferay7SDKDir + "\"");
}
}
else {
throw new ExecutionException("Unable to find Eclipse launcher");
}
if (launchDir.isDirectory()) {
ProcessBuilder processBuilder = new ProcessBuilder(commands);
processBuilder.directory(launchDir);
Map<String, String> environment = processBuilder.environment();
environment.putAll(System.getenv());
try {
processBuilder.start();
}
catch (IOException ioe) {
throw new ExecutionException("Unable to start Eclipse process", ioe);
}
}
return null;
}
} |
An astounding wonderment of nature, the St Regis Bora Bora Resort manages to encapsulate the harmony of Motu Ome’e with care, precision and sensitivity. Overwater villas gather around a crystalline lagoon, with ample space to retain a sense of privacy and seclusion, while villas line the pristine beachfront with private pools and generous sundecks. Embark on a culinary extravaganza, with LAGOON by Jean-Georges serving delectable French and Asian-infused cuisine and Te Pahu Restaurant offering a curated menu of authentic Polynesian dishes. Activities in the resort itself include the lavish Miri Miri Spa by CLARINS on its own private islet, as well as a swimming pool, water and land sports.
In Our Opinion
‘The staggering natural beauty of the island is complemented perfectly by the design of the resort. Nature lovers will adore the vast lagoon, mountain visages and crystal clear waters – this is very much paradise on earth.'
Deluxe Overwater Villa with Otemanu View
Situated further along the pontoon for added privacy, these beautiful Overwater Villas consists of a private terrace and gazebo as well as one generous bedroom and cosy living area with glass floor segment and offer fantastic views of Mount Otemanu
FEATURES
Garden Villa
Nestled along the water’s edge, the Garden Villa offers direct access to the pristine beachfront. Offering a gracious living room, outdoor garden with shower and plunge pool and fantastic views of the ocean, this villa is fantastic for honeymooners.
FEATURES
The Royal Estate
Comprising of three separate pavilions, each with a bedroom and en-suite bathroom, this spectacular residence incorporates a spa area, central swimming pool, private beach and communal living and dining area overlooking the gardens and sundeck.
Lagoon Restaurant by Jean-Gorges
This exclusive restaurant by Jean-Georges Vongerichten serves unparalleled French and Asian-infused cuisine. Using fresh produce and ingredients indigenous to the islands, each meal is a culinary delight complimented by views of the mythic Mount Otemanu. Specialities include the duo of veal and fresh mahi-mahi.
Bam Boo Restaurant
Bam Boo Restaurant is one of the first sushi and sake bars of the region, engaging in creativitiy, Japanese philosophy and premium seafood infused with pure flavours. Selections include shrimp tempura, chicken teriyaki and salmon rolls.
Aparima Bar
Location
The St Regis Resort is located on the outer barrier reef of Bora Bora, opposite the main island and its peak of Mount Otemanu. Access from the local airport on Motu Mute is via speedboat while the islands are serviced by Air Tahiti flights from Tahiti and other islands within French Polynesia.
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Contact number for booking related purposes only. Your details will only ever be used by us to contact you. We never pass your details to other parties. For more information read our Privacy Policy.
Please tell us your holiday requirements or questions
From time to time, Destinology would like to contact our customers with details of holiday special offers,
upgrade opportunities and holiday inspiration. We won't share your information with anyone else for marketing purposes,
so the only contact you will get will be from Destinology.
Are you happy to be contacted by:
Email
Yes
No
Please select Yes or No for marketing contact preference.
Thank you for contacting us
Thank you for contacting us. Your contact details and requirements have been sent and will be actioned by a Destinology travel consultant shortly.
Please note that depending on the time of day you have sent your booking enquiry, it may take up to 72 hours to contact to you.
Privacy Policy
DESTINOLOGY PRIVACY POLICY
This is the standard data protection privacy policy for the Destinology Limited.
When it comes to your privacy we never compromise. We will always be clear about why we need the details we ask for, and ensure your personal information is kept as secure as possible. How we do this is explained below.
Sharing your information (including information sent outside the European Economic Area - EEA)
Amendment and retention of information
Your rights
Updates to our Privacy Policy and your comments
Use of Cookies
1. INTRODUCTION
Destinology Limited is part of the Saga Group. The Saga Group, together with its subsidiaries are registered as data controllers with the Information Commissioner’s Office (ICO).
Destinology and Saga ("we","us") are committed to protecting your privacy. We comply with the principles of the General Data Protection Regulation (GDPR) and associated data protection legislation. We aim to maintain best-practice standards in our processing of personal and/or special category personal data (this is also referred to as sensitive personal data).
2. How we use your information
Destinology use the information we receive from you, together with information we have obtained from our dealings with you (including in relation to holiday services we provide to you and/or your use of those services), to provide holiday services that you request, to communicate with you, and to personalise information sent to you. Examples of how we may personalise information include working out which departure airports are near to you, or when we will be holding events in your area.
We do not sell, trade, or rent your personal information to others.
We store all the information you provide to us, including information provided via forms you complete on our website, and information which we may collect from your browsing. Our server, in common with nearly all web servers, logs each page that is downloaded from the site. If you contact us electronically we may collect your electronic identifier, e.g. Internet protocol (IP) address or phone number supplied by your service provider. This is to identify the number of visits to our websites, fraudulent behaviour or mystery shoppers using our websites.
Our website may also use SessionCam for analysis. SessionCam is a product that has been developed by SessionCam LTD. SessionCam may record mouse clicks, mouse movements, page scrolling and any text keyed into website forms. The information collected does not include bank details or any sensitive personal data. Data collected by SessionCam from the Saga website is for the Saga Group’s internal use only. The information collected is used to improve our website usability and is stored and used for aggregated and statistical reporting.
For further information; please see our ‘Use of Cookies section’.
We ask for your home, mobile phone number, and email address to enable us to contact you in relation to an enquiry you have made, to contact you if there is a problem with your order, notifying you about important functionality changes to the website, or if there is another genuine reason for doing so. For example, when you enter a contest or other promotional features, we use these details to administer the contest and notify winners.
Sometimes we may need to collect information that the law defines as special category data (also called sensitive personal data). This includes, but is not limited to, information about racial or ethnic origin, sexual orientation, health data, and criminal records. We will not collect or use these types of data without your consent, unless the law allows us to do so. If we do, it will only be when it is necessary as determined by the law and the ICO.
Any new information you provide to us may be used to update an existing record we hold for you. If you provide a work email address we will not be responsible for third parties having access to any communications we send.
We collect credit or debit card details from you in order to pay for a service or product. We will keep such details secure and ensure that the details are only used further with your consent and/or for the purposes of any appropriate refunds.
In the event of phone calls from you, we also reserve the right to ask security questions (which we in our sole discretion deem appropriate) in order to satisfy ourselves that you are who you say you are.
3. Fraud Prevention and Credit Checks
To help us prevent fraud and money laundering, your details may be submitted to fraud prevention agencies and other organisations where your records may be searched.
Our own security procedures mean that we may occasionally have to request proof of identity or check your presence on the electoral roll.
4. Lawful bases for using your information
Before you provide any data to us we will endeavour to make it clear why we need it. Sometimes we may need special category (sensitive) personal data, for example we may need medical information if you ask us to book an easy access room due to a disability. When this is required, we will obtain your consent first. Without this information, we may not be able to fulfil the product or service you have requested.
A customer may properly give their partner's consent over the phone or via the website providing the customer confirms they have permission to do so. If the consent is written, the spouse must independently endorse such consent via counter signature.
We use the information you provide to us, either orally or in writing and the information we obtain from you through the use of our website, and as a result of our dealings with you (including any data we obtain from third parties) to provide the service requested by you. It may also be used for market research, offering renewals and statistical purposes.
We recognise that we have a legitimate interest in processing the personal data we collect about you for a number of reasons, including, but not limited to: marketing purposes, to enables us to enhance, modify, personalise, or otherwise improve our services, identify and prevent fraud, enhance and protect the security of our network and systems, and market research (e.g. determining the effectiveness of campaigns and the products / services we offer). “Legitimate interests” means the interests of our company in conducting and managing our business to enable us to give you the best service and most secure experience.
When we use your information for our legitimate interests, we make sure to consider and balance any potential impact on you and your data protection rights. Where applicable, legitimate interest assessments are conducted to ensure that these rights are protected.
5. Keeping you informed about our products and services
When you contact us, either online or via one of our contact centres, we may ask for your permission to contact you about the products and services we offer. Where we have obtained your permission to do so we will contact you by post, telephone, email or other means to tell you about offers, products and services that may be of interest to you.
We also recognise that it is in our legitimate interests to send communications about our products and services, latest offers and rewards, so we may process your information to send you communications that are tailored to your interests.
At any time, you can opt out of receiving such information, revise the products you would like to hear about or change the method we use to communicate with you. You can update these preferences by calling us on 01204 474400 or by emailing helpdesk@destinology.co.uk.
We also use your personal information to make decisions about what products, services and offers we think you may be interested in. This is called profiling for marketing purposes. You can contact us at any time and ask us to stop using your personal information this way. If you allow it, we may show or send you marketing material online (on our own and other websites including social media), or by email, phone or post.
We make outbound phone calls for a number of reasons relating to our holiday products. We are fully committed to the regulations set out by Ofcom and follow strict processes to ensure we comply with them.
We may use personal data, collected in respect of one product to market another product that we may deem appropriate and relevant to you based on the information we have collected.
6. Sharing your information
As previously mentioned, we do not sell, trade or rent your information, and will never disclose information about you (including information obtained from our dealings with you) to third parties, except:
a) to fulfil your specific booking for a product or service or information in the event that third parties deliver the relevant product or service or information. For example, if you go on a holiday with us, the hotel needs to know who you are.
b) where third parties administer part or all of the product or service;
c) to maintain management information for business analysis.
We may of course be obliged by law to pass on your information to the police or any other statutory or regulatory authority and in some cases, exemptions may apply under relevant data protection legislation, whereby we can legitimately release personal data e.g. to prevent or detect crime or in connection with legal proceedings.
Subsequent to your purchase of a product or service, we may enter into an arrangement for that service to be provided by a new third party. If this happens, the terms and conditions of your contract with us will provide that you consent to the transfer and processing of personal and/or special category personal data to the new provider, subject to the requirements of the GDPR and associated legislation.
If we provide information to a third party (either a provider of a product or service, or an external data processing agency such as a mailing house), we will exercise the strictest control over them contractually, requiring it and any of its agents and/or suppliers to:
maintain the security and confidentiality of the information and restrict access to those of its own employees
use the data for the agreed purpose only and prevent it being used for any other purpose by any other party
refrain from communicating with you other than concerning the product in question
return the data to us at the conclusion of any contract term, and destroy or delete any copies made of all or any part of the information unless copies are needed to be kept to comply with regulations
In addition, we will restrict the information disclosed to the absolute minimum necessary, for example, to provide the product or service.
6. Information sent outside the EEA
We provide products and services including holidays outside the EEA. Therefore, if you travel on such holidays the information you provide may occasionally be transferred outside the EEA. From time to time Saga may use service providers and organisations outside the EEA for the purpose of processing services, system testing and maintenance.
It is worth noting, however, that some non-EEA countries do not afford the same level of data security as the UK. We will always use every reasonable effort to ensure sufficient protections are in place to safeguard your personal information.
7. Amendment and retention of information
Please advise us in writing as to any changes in your circumstances, or if you feel we hold inaccurate information about you so that we can update our records accordingly.
We will hold your personal information in accordance with the principles of the GDPR (and associated legislation) and in line with our Data Retention Policy. We are obliged and permitted by law and regulation to retain certain types of data for a minimum period of time. The minimum period of time tends to be for six years but can be longer if the statute or regulation requires.
8. Your rights
Access to your information: You have a statutory right of access to accessible personal and/or sensitive personal data that we hold about you. In order to exercise this right, your application must be in writing, either via letter or email. Please refer to the information you wish to see giving dates if possible. Please note that where relevant we may ask for proof of your identity.
We will not administer Subject Access Requests by a third party unless accompanied by a written authority of the individual who is the subject of the request.
We have one month to respond to a valid request.
Rights related to automated decision making including profiling: We use the information we know about you to make decisions which inform our pricing, fraud prevention and the products and services we can offer. Automated decision making enables us to make efficient and fair decisions, providing a better service for our customers. Whilst you have the right to object to us using your information in this way, this could have an impact on the products or services we may be able to offer you. We use automated decision making in the following areas:
Tailoring our marketing communications – as mentioned previously, we use your personal information to make decisions about what products, services and offers we think you may be interested in. This ensures the communications you receive from us are tailored and relevant to your interests. You can opt out of this at any time by contacting the Data Protection Officer.
The right to erasure: you have the right to request that your personal data is erased and to prevent processing in specific circumstances which are detailed by the ICO.
The right to data portability: you have the right to obtain and reuse the personal data that you have provided to us for your own purposes which includes transferring it to other services.
For further information regarding your rights, or to make a request; please write to the Data Protection Officer at The Saga Building, Enbrook Park, Sandgate, Kent CT20 3SE or email data.protection@saga.co.uk.
9. Updates to our privacy policy and your comments
If we decide to change our privacy policy, we will update all relevant documentation and post any changes on our websites so that you are always aware of what information we collect, how we use it, and under what circumstances we disclose it.
You have the right to lodge a complaint with the Information Commissioner’s Office (ICO) if you feel your personal information has not been handled correctly. You can do this via https://ico.org.uk/concerns/ or by writing to: Information Commissioner's Office, Wycliffe House, Water Lane, Wilmslow, Cheshire, SK9 5AF
10. Use of Cookies
A cookie is a piece of text based information that a website transfers to your computer’s hard drive. When using selected services on our website, we will use cookies to help recognise you and the bookings you have made.
If your browser is set to reject the use of cookies, you will be unable to use selected online services such as ‘View My Booking’ and ‘Check My Booking’. In this situation, please contact our Customer Services department who will be able to access this booking information.
The Foreign and Commonwealth Office (FCO) provide the latest travel advice by country including safety and security, entry requirements, travel warnings and health. For the latest FCO advice
please refer to www.gov.uk/travelaware Current travel health information can be found by visiting www.travelhealthpro.org.uk
a resource set up by the Department of Health. The advice can change on all sites so please check regularly for updates.
A specialist will be in touch to help you within 24 hours, likely less.
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We like to share exclusive special offers & holiday inspiration by email. We don’t pass your details on to anyone else. Here’s our Privacy Policy
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DESTINOLOGY PRIVACY POLICY
This is the standard data protection privacy policy for the Destinology Limited.
When it comes to your privacy we never compromise. We will always be clear about why we need the details we ask for, and ensure your personal information is kept as secure as possible. How we do this is explained below.
Sharing your information (including information sent outside the European Economic Area - EEA)
Amendment and retention of information
Your rights
Updates to our Privacy Policy and your comments
Use of Cookies
1. INTRODUCTION
Destinology Limited is part of the Saga Group. The Saga Group, together with its subsidiaries are registered as data controllers with the Information Commissioner’s Office (ICO).
Destinology and Saga ("we","us") are committed to protecting your privacy. We comply with the principles of the General Data Protection Regulation (GDPR) and associated data protection legislation. We aim to maintain best-practice standards in our processing of personal and/or special category personal data (this is also referred to as sensitive personal data).
2. How we use your information
Destinology use the information we receive from you, together with information we have obtained from our dealings with you (including in relation to holiday services we provide to you and/or your use of those services), to provide holiday services that you request, to communicate with you, and to personalise information sent to you. Examples of how we may personalise information include working out which departure airports are near to you, or when we will be holding events in your area.
We do not sell, trade, or rent your personal information to others.
We store all the information you provide to us, including information provided via forms you complete on our website, and information which we may collect from your browsing. Our server, in common with nearly all web servers, logs each page that is downloaded from the site. If you contact us electronically we may collect your electronic identifier, e.g. Internet protocol (IP) address or phone number supplied by your service provider. This is to identify the number of visits to our websites, fraudulent behaviour or mystery shoppers using our websites.
Our website may also use SessionCam for analysis. SessionCam is a product that has been developed by SessionCam LTD. SessionCam may record mouse clicks, mouse movements, page scrolling and any text keyed into website forms. The information collected does not include bank details or any sensitive personal data. Data collected by SessionCam from the Saga website is for the Saga Group’s internal use only. The information collected is used to improve our website usability and is stored and used for aggregated and statistical reporting.
For further information; please see our ‘Use of Cookies section’.
We ask for your home, mobile phone number, and email address to enable us to contact you in relation to an enquiry you have made, to contact you if there is a problem with your order, notifying you about important functionality changes to the website, or if there is another genuine reason for doing so. For example, when you enter a contest or other promotional features, we use these details to administer the contest and notify winners.
Sometimes we may need to collect information that the law defines as special category data (also called sensitive personal data). This includes, but is not limited to, information about racial or ethnic origin, sexual orientation, health data, and criminal records. We will not collect or use these types of data without your consent, unless the law allows us to do so. If we do, it will only be when it is necessary as determined by the law and the ICO.
Any new information you provide to us may be used to update an existing record we hold for you. If you provide a work email address we will not be responsible for third parties having access to any communications we send.
We collect credit or debit card details from you in order to pay for a service or product. We will keep such details secure and ensure that the details are only used further with your consent and/or for the purposes of any appropriate refunds.
In the event of phone calls from you, we also reserve the right to ask security questions (which we in our sole discretion deem appropriate) in order to satisfy ourselves that you are who you say you are.
3. Fraud Prevention and Credit Checks
To help us prevent fraud and money laundering, your details may be submitted to fraud prevention agencies and other organisations where your records may be searched.
Our own security procedures mean that we may occasionally have to request proof of identity or check your presence on the electoral roll.
4. Lawful bases for using your information
Before you provide any data to us we will endeavour to make it clear why we need it. Sometimes we may need special category (sensitive) personal data, for example we may need medical information if you ask us to book an easy access room due to a disability. When this is required, we will obtain your consent first. Without this information, we may not be able to fulfil the product or service you have requested.
A customer may properly give their partner's consent over the phone or via the website providing the customer confirms they have permission to do so. If the consent is written, the spouse must independently endorse such consent via counter signature.
We use the information you provide to us, either orally or in writing and the information we obtain from you through the use of our website, and as a result of our dealings with you (including any data we obtain from third parties) to provide the service requested by you. It may also be used for market research, offering renewals and statistical purposes.
We recognise that we have a legitimate interest in processing the personal data we collect about you for a number of reasons, including, but not limited to: marketing purposes, to enables us to enhance, modify, personalise, or otherwise improve our services, identify and prevent fraud, enhance and protect the security of our network and systems, and market research (e.g. determining the effectiveness of campaigns and the products / services we offer). “Legitimate interests” means the interests of our company in conducting and managing our business to enable us to give you the best service and most secure experience.
When we use your information for our legitimate interests, we make sure to consider and balance any potential impact on you and your data protection rights. Where applicable, legitimate interest assessments are conducted to ensure that these rights are protected.
5. Keeping you informed about our products and services
When you contact us, either online or via one of our contact centres, we may ask for your permission to contact you about the products and services we offer. Where we have obtained your permission to do so we will contact you by post, telephone, email or other means to tell you about offers, products and services that may be of interest to you.
We also recognise that it is in our legitimate interests to send communications about our products and services, latest offers and rewards, so we may process your information to send you communications that are tailored to your interests.
At any time, you can opt out of receiving such information, revise the products you would like to hear about or change the method we use to communicate with you. You can update these preferences by calling us on 01204 474400 or by emailing helpdesk@destinology.co.uk.
We also use your personal information to make decisions about what products, services and offers we think you may be interested in. This is called profiling for marketing purposes. You can contact us at any time and ask us to stop using your personal information this way. If you allow it, we may show or send you marketing material online (on our own and other websites including social media), or by email, phone or post.
We make outbound phone calls for a number of reasons relating to our holiday products. We are fully committed to the regulations set out by Ofcom and follow strict processes to ensure we comply with them.
We may use personal data, collected in respect of one product to market another product that we may deem appropriate and relevant to you based on the information we have collected.
6. Sharing your information
As previously mentioned, we do not sell, trade or rent your information, and will never disclose information about you (including information obtained from our dealings with you) to third parties, except:
a) to fulfil your specific booking for a product or service or information in the event that third parties deliver the relevant product or service or information. For example, if you go on a holiday with us, the hotel needs to know who you are.
b) where third parties administer part or all of the product or service;
c) to maintain management information for business analysis.
We may of course be obliged by law to pass on your information to the police or any other statutory or regulatory authority and in some cases, exemptions may apply under relevant data protection legislation, whereby we can legitimately release personal data e.g. to prevent or detect crime or in connection with legal proceedings.
Subsequent to your purchase of a product or service, we may enter into an arrangement for that service to be provided by a new third party. If this happens, the terms and conditions of your contract with us will provide that you consent to the transfer and processing of personal and/or special category personal data to the new provider, subject to the requirements of the GDPR and associated legislation.
If we provide information to a third party (either a provider of a product or service, or an external data processing agency such as a mailing house), we will exercise the strictest control over them contractually, requiring it and any of its agents and/or suppliers to:
maintain the security and confidentiality of the information and restrict access to those of its own employees
use the data for the agreed purpose only and prevent it being used for any other purpose by any other party
refrain from communicating with you other than concerning the product in question
return the data to us at the conclusion of any contract term, and destroy or delete any copies made of all or any part of the information unless copies are needed to be kept to comply with regulations
In addition, we will restrict the information disclosed to the absolute minimum necessary, for example, to provide the product or service.
6. Information sent outside the EEA
We provide products and services including holidays outside the EEA. Therefore, if you travel on such holidays the information you provide may occasionally be transferred outside the EEA. From time to time Saga may use service providers and organisations outside the EEA for the purpose of processing services, system testing and maintenance.
It is worth noting, however, that some non-EEA countries do not afford the same level of data security as the UK. We will always use every reasonable effort to ensure sufficient protections are in place to safeguard your personal information.
7. Amendment and retention of information
Please advise us in writing as to any changes in your circumstances, or if you feel we hold inaccurate information about you so that we can update our records accordingly.
We will hold your personal information in accordance with the principles of the GDPR (and associated legislation) and in line with our Data Retention Policy. We are obliged and permitted by law and regulation to retain certain types of data for a minimum period of time. The minimum period of time tends to be for six years but can be longer if the statute or regulation requires.
8. Your rights
Access to your information: You have a statutory right of access to accessible personal and/or sensitive personal data that we hold about you. In order to exercise this right, your application must be in writing, either via letter or email. Please refer to the information you wish to see giving dates if possible. Please note that where relevant we may ask for proof of your identity.
We will not administer Subject Access Requests by a third party unless accompanied by a written authority of the individual who is the subject of the request.
We have one month to respond to a valid request.
Rights related to automated decision making including profiling: We use the information we know about you to make decisions which inform our pricing, fraud prevention and the products and services we can offer. Automated decision making enables us to make efficient and fair decisions, providing a better service for our customers. Whilst you have the right to object to us using your information in this way, this could have an impact on the products or services we may be able to offer you. We use automated decision making in the following areas:
Tailoring our marketing communications – as mentioned previously, we use your personal information to make decisions about what products, services and offers we think you may be interested in. This ensures the communications you receive from us are tailored and relevant to your interests. You can opt out of this at any time by contacting the Data Protection Officer.
The right to erasure: you have the right to request that your personal data is erased and to prevent processing in specific circumstances which are detailed by the ICO.
The right to data portability: you have the right to obtain and reuse the personal data that you have provided to us for your own purposes which includes transferring it to other services.
For further information regarding your rights, or to make a request; please write to the Data Protection Officer at The Saga Building, Enbrook Park, Sandgate, Kent CT20 3SE or email data.protection@saga.co.uk.
9. Updates to our privacy policy and your comments
If we decide to change our privacy policy, we will update all relevant documentation and post any changes on our websites so that you are always aware of what information we collect, how we use it, and under what circumstances we disclose it.
You have the right to lodge a complaint with the Information Commissioner’s Office (ICO) if you feel your personal information has not been handled correctly. You can do this via https://ico.org.uk/concerns/ or by writing to: Information Commissioner's Office, Wycliffe House, Water Lane, Wilmslow, Cheshire, SK9 5AF
10. Use of Cookies
A cookie is a piece of text based information that a website transfers to your computer’s hard drive. When using selected services on our website, we will use cookies to help recognise you and the bookings you have made.
If your browser is set to reject the use of cookies, you will be unable to use selected online services such as ‘View My Booking’ and ‘Check My Booking’. In this situation, please contact our Customer Services department who will be able to access this booking information. |
Used rubber tires have been causing a pollution problem since they replaced the wagon wheel. They are bulky, do not break down on their own, and quickly cause landfills to fill up. On occasion, used tires catch fire and can burn for days or weeks, releasing harmful pollutants both into the atmosphere and into the groundwater.
Some efforts have been made to chop up used tires and reassemble them into a useful product. With glue or heat, chopped tires can be made into floor padding for gyms, machine shops and playgrounds. Chopped tires can be used as mulch or ground cover or they can be used to manufacture sandals, welcome mats and rubber speed bumps. The problem of removing steel belts from tires is difficult to solve, so tires with steel belts may not be suitable for recycling in these applications. Another problem is that making these products from recycled tires costs more than making them from virgin materials, and customers are suspicious that the recycled products may contain carcinogens and other hazardous substances. Therefore, the cost of recycling used tires and public suspicion of them remain issues to be resolved.
Another option for recycling used tires is heat-based pyrolysis. For example, U.S. Pat. No. 8,475,726 for “Reactor and apparatus for pyrolyzing waste, especially tyres” discloses heating used tires to cause them to pyrolize, allowing separation of oils, metal and carbon black. Decades of experimentation with such systems have shown them to be energy-inefficient, resulting in most used tires making their way to landfills. Such systems also have a problem with leaving hazardous materials, including heavy metals, in the recycled material.
An alternative method for recycling used tires is to break down the vulcanized chemical bonds through radio frequency pyrolysis. Such systems in theory hold academic promise but have not proven commercially viable.
Another method for recycling tires employs chemical devulcanization through the addition of diphenyl disulfide and heat to the tires. This system has proven to be dirty, expensive to implement, and creates a substantial pollution problem.
Photo devulcanization processing of used tires is another possibility. In this system, the recycler mixes a photoreactive material with used tires and exposes the photoreactive material to light. The light causes the photoreactive material to build up heat and pyrolize the tire. This method has not been commercially successful due to the problem of chopped used tires being opaque.
Therefore there is a need for a method for recycling used tires which is energy-efficient, does not cause environmental pollution, and deals with the issues of steel in the tires as well as hazardous waste that tire recycling can create. |
All Age Gaming’s 2013 Game of the Year Award
Tyler from All Age Gaming writes "Our fair readers, another year in gaming has come and gone. 2013 was a brilliant year, full of brilliant, well-made games for players of every type. However, for every single passionately made, emotionally charged and intellectually involved experience released this year, there were also idiotically made pieces of dross to match. This was the year that gave us the likes of The Last of Us and Legend of Zelda: Link Between Worlds, only to be balanced by Aliens: Colonial Marines and Ride to Hell: Retribution." |
Displacement current on purple membrane fragments oriented in a suspension.
The displacement current is measured in a suspension of electric field-oriented purple membranes isolated from Halobacterium halobium, the photocycle being driven by a light flash. A simple quantitative theory of the method is presented and used to evaluate the distances the protons move during their way through the bacteriorhodopsin molecules. A lower limit of the velocity of proton movement is also given. |
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|
<?xml version="1.0" encoding="UTF-8"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
-->
<document xmlns="http://maven.apache.org/XDOC/2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/XDOC/2.0 http://maven.apache.org/xsd/xdoc-2.0.xsd">
<properties>
<title>IAM Scenario</title>
<author email="dev@syncope.apache.org">Apache Syncope Documentation Team</author>
</properties>
<body>
<section name="Identity and Access Management - Reference Scenario">
<p style="text-align:center;">
<img src="docs/images/iam-scenario.png" alt="IAM Scenario" width="700"/>
</p>
<p>
The picture above shows the tecnologies involved in a complete IAM solution:
<ul>
<li>
<strong>
<em>Identity Store</em>
</strong>
<br/>
(as RDBMS, LDAP, Active Directory, meta- and virtual-directories), the repository for account data
</li>
<li>
<strong>
<em>Provisioning Engine</em>
</strong>
<br/>
synchronizes account data across identity stores and a broad range of data formats, models, meanings and
purposes
</li>
<li>
<strong>
<em>Access Manager</em>
</strong>
<br/>
access mediator to all applications, focused on application front-end, taking care
of <u>authentication</u>
(<a href="https://en.wikipedia.org/wiki/Single_sign-on" target="_blank">Single Sign-On</a>),
<u>authorization</u>
(<a href="http://oauth.net/" target="_blank">OAuth</a>,
<a href="https://en.wikipedia.org/wiki/XACML">XACML</a>) and <u>federation</u>
(<a href="https://en.wikipedia.org/wiki/Security_Assertion_Markup_Language" target="_blank">SAML</a>,
<a href="http://openid.net/connect/" target="_blank">OpenID Connect</a>).
</li>
</ul>
</p>
<hr/>
<p style="text-align:center;">
As you can notice,<b>
<u>Apache Syncope is primarily a provisioning engine</u>
</b>.
</p>
<hr/>
<subsection name="Aren't Identity Stores enough?">
One might suppose that a single identity store can solve all the identity needs inside an organization, but few
drawbacks are just around the corner:
<ol>
<li>Heterogeneity of systems</li>
<li>Lack of a single source of information (HR for corporate id, Groupware for mail address, ...)</li>
<li>Often applications require a local user database</li>
<li>Inconsistent policies across the infrastructure</li>
<li>Lack of workflow management</li>
<li>Hidden infrastructure management cost, growing with organization</li>
</ol>
</subsection>
</section>
</body>
</document>
|
Display devices for use in TVs, cell phones, etc., and optical elements, such as camera lenses, etc., usually adopt an antireflection technique in order to reduce the surface reflection and increase the amount of light transmitted therethrough. This is because, when light is transmitted through the interface between media of different refractive indices, e.g., when light is incident on the interface between air and glass, the amount of transmitted light decreases due to, for example, Fresnel reflection, thus deteriorating the visibility.
An antireflection technique which has been receiving attention in recent years is forming over a substrate surface a very small uneven pattern in which the interval of recessed portions or raised portions is not more than the wavelength of visible light (λ=380 nm to 780 nm). See Patent Documents 1 to 4. The two-dimensional size of a raised portion of an uneven pattern which performs an antireflection function is not less than 10 nm and less than 500 nm.
This method utilizes the principles of a so-called moth-eye structure. The refractive index for light that is incident on the substrate is continuously changed along the depth direction of the recessed portions or raised portions, from the refractive index of a medium on which the light is incident to the refractive index of the substrate, whereby reflection of a wavelength band that is subject to antireflection is prevented.
The moth-eye structure is advantageous in that it is capable of performing an antireflection function with small incident angle dependence over a wide wavelength band, as well as that it is applicable to a number of materials, and that an uneven pattern can be directly formed in a substrate. As such, a high-performance antireflection film (or antireflection surface) can be provided at a low cost.
As the method of forming a moth-eye structure, using an anodized porous alumina layer which is obtained by means of anodization of aluminum has been receiving attention (Patent Documents 2 to 4).
Now, the anodized porous alumina layer which is obtained by means of anodization of aluminum is briefly described. Conventionally, a method of forming a porous structure by means of anodization has been receiving attention as a simple method for making nanometer-scale micropores (very small recessed portions) in the shape of a circular column in a regular arrangement. An aluminum base is immersed in an acidic electrolytic solution of sulfuric acid, oxalic acid, phosphoric acid, or the like, or an alkaline electrolytic solution, and this is used as an anode in application of a voltage, which causes oxidation and dissolution. The oxidation and the dissolution concurrently advance over a surface of the aluminum base to form an oxide film which has micropores over its surface. The micropores, which are in the shape of a circular column, are oriented vertical to the oxide film and exhibit a self-organized regularity under certain conditions (voltage, electrolyte type, temperature, etc.). Thus, this anodized porous alumina layer is expected to be applied to a wide variety of functional materials.
A porous alumina layer formed under specific conditions includes cells in the shape of a generally regular hexagon which are in a closest packed two-dimensional arrangement when seen in a direction perpendicular to the film surface. Each of the cells has a micropore at its center. The arrangement of the micropores is periodic. The cells are formed as a result of local dissolution and growth of a coating. The dissolution and growth of the coating concurrently advance at the bottom of the micropores which is referred to as a barrier layer. As known, the interval between adjacent micropores (the distance between the centers), is approximately twice the thickness of the barrier layer, and is approximately proportional to the voltage that is applied during the anodization. It is also known that the diameter of the micropores depends on the type, concentration, temperature, etc., of the electrolytic solution but is, usually, about ⅓ of the size of the cells (the length of the longest diagonal of the cell when seen in a direction vertical to the film surface). Such micropores of the porous alumina may constitute an arrangement which has a high regularity (periodicity) under specific conditions, an arrangement with a regularity degraded to some extent depending on the conditions, or an irregular (non-periodic) arrangement.
Patent Document 2 discloses a method of producing an antireflection film (antireflection surface) with the use of a stamper which has an anodized porous alumina film over its surface.
Patent Document 3 discloses the technique of forming tapered recesses with continuously changing pore diameters by repeating anodization of aluminum and a pore diameter increasing process.
The applicant of the present application discloses, in Patent Document 4, the technique of forming an antireflection film with the use of an alumina layer in which very small recessed portions have stepped lateral surfaces.
As described in Patent Documents 1, 2, and 4, by providing an uneven structure (macro structure) which is greater than a moth-eye structure (micro structure) in addition to the moth-eye structure, the antireflection film (antireflection surface) can be provided with an antiglare function. The two-dimensional size of a raised portion of the uneven structure which is capable of performing the antiglare function is not less than 1 μm and less than 100 μm.
Utilizing an anodized porous aluminum film can facilitate the manufacture of a mold which is used for formation of a moth-eye structure over a surface (hereinafter, “moth-eye mold”). In particular, as described in Patent Documents 2 and 4, when the surface of the anodized aluminum film as formed is used as a mold without any modification, a large effect of reducing the manufacturing cost is achieved. The structure of the surface of a moth-eye mold which is capable of forming a moth-eye structure is herein referred to as “inverted moth-eye structure”.
A known antireflection film production method with the use of a moth-eye mold uses a photocurable resin. Firstly, a photocurable resin is applied over a substrate. Then, an uneven surface of a moth-eye mold which has undergone a mold release treatment is pressed against the photocurable resin in vacuum, whereby the uneven structure at the surface of the moth-eye mold is filled with the photocurable resin. Then, the photocurable resin in the uneven structure is irradiated with ultraviolet light so that the photocurable resin is cured. Thereafter, the moth-eye mold is separated from the substrate, whereby a cured layer of the photocurable resin to which the uneven structure of the moth-eye mold has been transferred is formed over the surface of the substrate. The method of producing an antireflection film with the use of the photocurable resin is disclosed in, for example, Patent Document 4.
The above-described moth-eye mold can be fabricated using an aluminum base, such as typically a substrate made of aluminum or a cylinder made of aluminum, or an aluminum film formed on a support that is made of a non-aluminum material, such as typically a glass substrate. However, in a moth-eye mold manufactured using an aluminum film formed on a glass substrate or plastic film, the adhesive property between the aluminum film (part of which is an anodized film) and the glass substrate or plastic film deteriorates in some cases. The applicant of the present application found that, by forming an inorganic underlayer (e.g., SiO2 layer) and a buffer layer containing aluminum (e.g., AlOx layer) on a surface of a base which is made of glass or plastic, the above-described deterioration of the adhesive property is prevented. This is disclosed in Patent Document 5.
The applicant of the present application developed a method for efficiently producing an antireflection film using a moth-eye mold in the form of a cylinder (roll) according to a roll-to-roll method (e.g., WO 2011/105206). The moth-eye mold in the form of a cylinder can be formed by, for example, forming an organic insulating layer over an outer perimeter surface of a metal cylinder, forming an aluminum film on this organic insulating layer, and alternately and repeatedly performing anodization and etching on the aluminum film. In this case also, the adhesive property can be improved by forming the inorganic underlayer and the buffer layer disclosed in Patent Document 5.
According to further researches carried out by the present inventors, an aluminum film formed on an organic insulating layer contains abnormal grains in many cases. The abnormal grains are formed by abnormal growth of a crystal of aluminum. The aluminum film is an aggregation of crystal grains whose average grain diameter (average grain size) is about 200 nm. On the other hand, the grain diameter of the abnormal grains is larger than the average grain diameter, e.g., not less than 500 nm in some cases. The organic insulating layer has a lower thermal conductivity than the other materials (metal materials and inorganic insulating films), and therefore, the aluminum film readily reaches a relatively high temperature in the process of depositing the aluminum film (e.g., sputtering or vapor deposition). As a result, it is inferred that abnormal growth of crystal grains is likely to occur, i.e., abnormal grains are likely to be produced. Note that such a phenomenon can also occur when an aluminum film is directly deposited on a surface of an aluminum pipe (e.g., the thickness is not less than 1 mm).
When a moth-eye mold is manufactured using an aluminum film in which abnormal grains are present, structures corresponding to the abnormal grains are formed in the surface of a porous alumina layer of the moth-eye mold. When an antireflection film is formed using such a moth-eye mold, the structures corresponding to the abnormal grains are transferred to the surface of the antireflection film. Therefore, light is scattered by the structures transferred to the surface of the antireflection film which are attributed to the abnormal grains. That is, the antireflection film has a haze. In the case where the antireflection film is provided with an antiglare function as described above, no problem occurs in some cases even when the antireflection film has a haze which is attributed to the abnormal grains. However, there is such a problem that an antireflection film which does not have an antiglare function cannot be producing. Further, it is difficult to control the formation density (frequency of occurrence) of abnormal grains, and therefore, from the viewpoint of mass productivity, preventing production of abnormal grains is preferred.
The present inventors disclose in the international patent application (PCT/JP2012/058394, WO 2012/137664) that an aluminum alloy layer which contains aluminum and such a metal element that the absolute value of the difference between the standard electrode potential of the metal element and the standard electrode potential of aluminum is not more than 0.64 V (for example, the metal element may be Ti, Nd, Mn, Mg, Zr, V, and Pb, and the content of the metal element in the entire aluminum alloy layer is less than 10 mass %) scarcely contains abnormal grains, and as a result, a mold can be obtained which is capable of producing an antireflection film that does not have an undesirable haze.
The entire disclosures of Patent Documents 1, 2, 4, and 5 and the above-identified international patent application are herein incorporated by reference. |
Nursing students' attitudes toward research and development within nursing: Does writing a bachelor thesis make a difference?
The aim of this study was to investigate the effect of writing a bachelor's thesis on nursing students' attitudes towards research and development in nursing. The study sample consisted of 91 nursing students who were required to complete a bachelor's thesis and 89 nursing students who were not required to complete a bachelor's thesis. Data were collected via self-report questionnaire that was distributed in May and June 2012. The questionnaire comprised 3 parts: (1) demographic items; (2) questions about "scientific activities," and (3) the nursing students' attitudes towards and awareness of research and development within nursing scale (version 2). The mean age of the students was 23 (1.3) years. The students who wrote a bachelor's thesis achieved a median score of 110.0, whereas the students in the other group had a median score of 105.0 on the scale. All the items were assigned a 3 or higher. A statistically significant difference was found between the 2 groups in their attitudes towards and awareness of research (U = 3265.5; P = .025). The results of this study suggest that writing a thesis in nursing education has a positive influence on nursing students' attitudes towards and awareness of research and development in nursing. |
Q:
How to import latest database backup file to backup server
I want to import the backup database file in *.sql.gz to my backup server.
I try to use the follow command but there is an error with it
ls -Art *.sql.gz | tail -n 1 | gunzip -c | mysql --user=user --password=password database
gzip: stdin: not in gzip format
So how can I pipe the latest files to gunzip is correct.
A:
Try using xargs:
ls -Art *.sql.gz |tail -n 1 |xargs gunzip -c | mysql --user=user --password=password database
|
Most Americans don’t really care about contemporary political issues or the rudimentary workings of their government. But they sure do love voting. And the biggest fans of “democracy” treat this orgy of vacuous lever-pulling as if it were sacred or patriotic. It is neither. In 2013, President Barack Obama, who’s often argued that voting should be easier, issued an undemocratic Executive Order to create a commission to investigate how to expand participation in democracy.
A superb report released Wednesday by the Presidential Commission on Election Administration can be summarized in one quick sentence: There are many ways to make voting easier in America. There shouldn’t be the slightest whiff of controversy or partisanship about that concept, or the important suggestions made in the report. But, of course, there is, and that makes the commission’s persuasive logic and research all the more valuable.
I can summarize the report in one sentence, as well: Let’s degrade elections in America. The report, for example, suggests that no one in the country should have to wait longer than “30 minutes” to cast a ballot – or, in other words, voting should entail 15 minutes less exertion than ordering Chinese takeout. Nowhere within the recommendations – or elsewhere, for that matter – do we ever ponder whether voters have a civic responsibility to know who the vice president is before getting an ‘I voted’ sticker.
A recent Pew survey found that little more than a third of American adults can name the three branches of government and 35 percent can’t name a single one. Only 38 percent of Americans could correctly identify which party controls the House or the Senate, and more than 40 percent “didn’t even feel qualified to guess at the leadership of each house of Congress.” There are dozens – hundreds – of surveys over the years that confirm the fact that majority of Americans care more about anything than they do about foreign policy. And while there’s no shame in being turned off by the cavity of Washington DC, there might be something shameful about nullifying the vote of a citizen who took the time to figure out the difference between Medicare and Medicaid.
Accountability is a downer. Making things “easy” is empowering. Last week, in Colorado, scores of negligent teachers and their pliable students took to the streets to protest the implementation of a curriculum that goes heavy on teaching the responsibilities of citizenship rather than romanticizing the state. (The curriculum, it should be mentioned, was implemented using the democratic process that unions claim to hold in such high esteem.)
Is it any wonder that so many young people have ridiculously outsized expectations about what government can or should be doing? Is it any wonder that so many people can be so easily manipulated with emotional appeals – and the kind “bed-wetting” and scaremongering we hear every day? “Hence the concentration of power and the subjection of individuals will increase among democratic nations,” says Tocqueville, “not only in the same proportion as their equality, but in the same proportion as their ignorance.” Sounds about right.
In Ohio, for example, a person can vote four weeks before the election. And if you forget to register, feel free to do it on the day of the election. And if that wasn’t enough to degrade the supposed sanctity of the democratic process, this week the Supreme Court stopped the state from offering an extra week that would have allowed people to both register to vote and vote. The Supreme Court also eliminated voting on the Sunday before Election Day. This will make it more difficult for churches to organize their flock to vote lockstep. We should be discouraging this sort of communal voting as much as we should be discouraging paper ballots, which are not only haphazardly mailed out but create a situation that leaves millions susceptible to manipulation by friends and family members. Ideally, an American should stand on a long line before being sequestered to ponder long and hard the gravity of the mistake they’re about to make.
Unlike others, I’m not worried about widespread fraud – though it certainly happens on occasion. I’m worried about too many uninformed and unmotivated people registering to vote. We should demand some effort. And despite perceptions, I’m not alone in these thoughts. According to the latest poll on the topic, Rasmussen found that only 17 percent of likely voters believe it’s too hard to vote in the United States, while 27 percent think it’s too easy – and 50 percent feel the level of difficulty is just right.
Now, it’s likely that this poll has to do with partisanship, fear of fraud or race. In addition to the recent decision in Ohio, in states like North Carolina, Texas and Arkansas, the process of tightening voting procedures is underway. Some argue that these laws undermine the participation of African Americans. Considering our ugly history on this matter, accusations like this should not be taken lightly. And, as Americans, we must do our best to make voting equally onerous for all races and creeds. |
Previous approaches to shipping fragile components (i.e., hard drives) have typically utilized substances such as resilient foam, as well as adhesives and other non-recyclable materials when packaging such components.
For an example of a typical packaging system, please refer now to FIG. 1. FIG. 1 is an exploded view of a typical packaging system for fragile components such as a hard drive. This approach utilizes a polyurethane bottom cushion 12, a polyurethane middle cushion 14, a polyurethane top cushion 16 and a corrugated tray 18, all of which fit into a corrugated carton 10. Utilizing this approach, the component to be shipped (not shown) is inserted between the polyurethane top cushion 16 and the polyurethane bottom cushion 12, through the polyurethane middle cushion 14. However, as previously mentioned, a drawback to this approach is the high cost of the polyurethane material, as well as the fact that polyurethane is not biodegradable and thus not environment friendly.
Accordingly, what is needed is a system and method which makes use of lower cost, environmentally safe and recyclable materials and yet safely protects fragile components from any potential damage that can be caused during the shipping process. The present invention addresses such a need. |
Q:
WPF Immediate binding to all TabControl TabItems
I am currently running into an issue where I want all of my tabs to be immediately bound to my ViewModel. For some reason, it seems that WPF doesn't bind my other TabItem's until I select them for the first time. I am eager for a solution in this because I have validation on those others tabs. Until the binding occurs on those other tabs, my app thinks everything is valid when it isnt. If it helps, I am using FluentValidation for my validation.
I have tried using someone's TabControlEx to see if that would help me but it doesn't. I also tried to cycle through all the tabs after I load the data to force the binding but that didn't always work on slower devices. I am not a fan of this solution either.
A:
I don't know why you are being voted down, seems like a valid question, but you will still get a vague answer, due to the nature of the TabControl:
The default style for WPF TabControl only contains a single ContentControl which is used for displaying all tabs. Thus, the visual tree representing a tabs content is created on demand; and tears down to be replaced with a new visual tree when the content/tab switches.
The common issue here, is that switching between tabs becomes slow, and thus there are a couple of solutions out there:
Binding to ItemsSource of TabControl in WPF
https://github.com/ButchersBoy/Dragablz
However, what happens with the solutions is that ContentPresenters are cached...but they still wont be created until a user first hits the tab. Thus, you will still have the same issue.
Thus you need some sort of architectural change. You need your set of view models to be validated from a trigger in code, on initial startup. Waiting for the tab control to render items just isn't going to work for you.
You probably need to bubble the error up in your view model hierarchy to display in the TabItem.Header or in the window itself; perhaps you might have a MainWindowViewModel where you can display a top level error.
|
Sexual dysfunction is a common problem afflicting men and women of all ages, genders, and races. Erectile dysfunction is a serious condition for many males, and it may include a variety of problems. Some of these problems include the inability to create an erection, incomplete erections and brief erectile periods. Sexual dysfunction in females may also affect the performance of erectile tissues, such as clitoris. These conditions may be associated with nervous system disorders, and may be caused by aging, injury, or illness.
In some cases, erectile dysfunction can be attributed to improper nerve activity that incompletely stimulates the penis or female erectile tissue. For example, stimulation from the brain during arousal and sexual activity is responsible for activating erectile tissue. With respect to erectile disorders, the problem may be a lack of sufficient stimulation from the brain, or a break in communication of the stimulation. Erectile disorders may additionally or alternatively involve dysfunctional parasympathetic function that can be attributed to many factors including illness or injury.
Methods for treating erectile dysfunction include pharmaceutical treatment and electrical stimulation. Delivery of electrical stimulation to nerves running through the pelvic floor may provide an effective therapy for many patients. For example, an implantable neurostimulator may be provided to deliver electrical stimulation to the pudendal or cavernous nerves to activate erectile tissue, e.g., induce an erection in males. |
Magnetic fields play an important role in a wide range of applications. They are used for instance in electric motors, dynamos and for signal transmission of radio or television. Furthermore, magnetic fields are used for medical diagnosis, where the most prominent example is magnetic resonance imaging (MRI). In each of these applications, the magnetic field is tailored to fulfill certain needs. For instance, in MRI, the formation of two field configurations is required: A spatially homogeneous and a linearly increasing gradient field. These special fields can be generated by electromagnetic coils, whereas the coil geometry and the applied current determine the field characteristics. For these simple field configurations, the optimal coil topology is well known. A homogeneous magnetic field is generated by a Helmholtz coil pair consisting of two identical coils that are placed symmetrically along a common axis, and separated by distance R equal to the coil radius. Each coil carries equal current owing in same direction. Similarly, a gradient field is generated by a Maxwell coil pair, which has the same topology but current owing in opposing direction and a larger coil distance of R√{square root over (3)}.
Magnetic Particle Imaging (MPI) is an emerging medical imaging modality. The first versions of MPI were two-dimensional in that they produced two-dimensional images. Future versions will be three-dimensional (3D). A time-dependent, or 4D, image of a non-static object can be created by combining a temporal sequence of 3D images to a movie, provided the object does not significantly change during the data acquisition for a single 3D image.
MPI is a reconstructive imaging method, like Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). Accordingly, an MP image of an object's volume of interest is generated in two steps. The first step, referred to as data acquisition, is performed using an MPI scanner. The MPI scanner has means to generate a static magnetic gradient field, called “selection field”, which has a single field free point (FFP) at the isocenter of the scanner. In addition, the scanner has means to generate a time-dependent, spatially nearly homogeneous magnetic field. Actually, this field is obtained by superposing a rapidly changing field with a small amplitude, called “drive field”, and a slowly varying field with a large amplitude, called “focus field”. By adding the time-dependent drive and focus fields to the static selection field, the FFP may be moved along a predetermined FFP trajectory throughout a volume of scanning surrounding the isocenter. The scanner also has an arrangement of one or more, e.g. three, receive coils and can record any voltages induced in these coils. For the data acquisition, the object to be imaged is placed in the scanner such that the object's volume of interest is enclosed by the scanner's field of view, which is a subset of the volume of scanning.
The object must contain magnetic nanoparticles; if the object is an animal or a patient, a contrast agent containing such particles is administered to the animal or patient prior to the scan. During the data acquisition, the MPI scanner steers the FFP along a deliberately chosen trajectory that traces out the volume of scanning, or at least the field of view. The magnetic nanoparticles within the object experience a changing magnetic field and respond by changing their magnetization. The changing magnetization of the nanoparticles induces a time dependent voltage in each of the receive coils. This voltage is sampled in a receiver associated with the receive coil. The samples output by the receivers are recorded and constitute the acquired data. The parameters that control the details of the data acquisition make up the scan protocol.
In the second step of the image generation, referred to as image reconstruction, the image is computed, or reconstructed, from the data acquired in the first step. The image is a discrete 3D array of data that represents a sampled approximation to the position-dependent concentration of the magnetic nanoparticles in the field of view. The reconstruction is generally performed by a computer, which executes a suitable computer program. Computer and computer program realize a reconstruction algorithm. The reconstruction algorithm is based on a mathematical model of the data acquisition. As with all reconstructive imaging methods, this model is an integral operator that acts on the acquired data; the reconstruction algorithm tries to undo, to the extent possible, the action of the model.
Such an MPI apparatus and method have the advantage that they can be used to examine arbitrary examination objects—e.g. human bodies—in a non-destructive manner and without causing any damage and with a high spatial resolution, both close to the surface and remote from the surface of the examination object. Such an arrangement and method are generally known and are first described in DE 101 51 778 A1 and in Gleich, B. and Weizenecker, J. (2005), “Tomographic imaging using the nonlinear response of magnetic particles” in nature, vol. 435, pp. 1214-1217. The arrangement and method for magnetic particle imaging (MPI) described in that publication take advantage of the non-linear magnetization curve of small magnetic particles.
In the paper Weizenecker J. et al., “Magnetic particle imaging using a field free line”, J. Phys. D: Appl. Phys. 41 (2008) 105009, a simulation study on the use of a field free line (FFL) in magnetic particle imaging is presented. Further, a schematic setup of the simulated scanner geometry and the path of the FFL are described. The setup comprises a ring of 32 small coils (selection field coils) producing the rotating FFL. Two pairs of larger loops (drive field coils) move this FFL over the field of view. The diameter of the selection field coil ring is 1 m. Superimposing the selection field and the drive field, the FFL moves along the drive field vector, which over time has the form of a rosette, provided that the orientation of the FFL is always perpendicular to the drive field vector. Hence, the FFL scans back and forth while rotating slowly. This setup has, however, significantly higher power losses than the above described MPI apparatus exploiting the use and movement of a FFP and, hence, might not be realizable. |
Q:
Making recyclerview fill entire page
I have a page that has a custom recyclerview. I want items I add to the recyclerview to pop up in a list. App was working just fine before I updated my AppCompact library. But essentially, I had anchored my FAB to a Coordinator layout, but I got an IllegalStateException and to resolve that, I had to anchor it to one of the Coordinator layout's children. I picked the recyclerview. But the problem now is that the recycler view does not fill the entire page. It only shows one item (I can scroll through them) but they only take up the space of one - like viewing one at a time. How do I make the layout work like it did before the update?
This is my xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:orientation="vertical"
android:gravity="center"
android:layout_height="match_parent">
<!--<include layout="@layout/base_toolbar"/>-->
<android.support.design.widget.CoordinatorLayout
android:id="@+id/myCoordinatorLayout"
android:layout_width="match_parent"
android:gravity="center"
android:layout_height="match_parent"
>
<LinearLayout
android:id="@+id/reminderEmptyView"
android:orientation="vertical"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:src="@drawable/empty_view_bg"
android:layout_width="100dp"
android:layout_height="100dp"/>
<TextView
android:text="Nothing added yet"
android:textColor="@color/secondary_text"
android:textSize="16sp"
android:paddingTop="4dp"
android:paddingBottom="8dp"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
<!--<include layout="@layout/base_toolbar"/>-->
<!--</android.support.design.widget.AppBarLayout>-->
<apps.todo.Utility.RecyclerViewEmptySupport
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:id="@+id/toDoRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<android.support.design.widget.FloatingActionBut
A:
You probably don't need that parent LinearLayout.
Just copy
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
These into your CoordinatorLayout.
Then remove gravity from your Coordinator Layout and change your FloatingActionButton to:
<android.support.design.widget.FloatingActionButton
android:src="@drawable/ic_add_white_24dp"
android:id="@+id/addToDoItemFAB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:layout_gravity="bottom|end"/>
This fixes the connection between your RecyclerView and FAB.
This Blog post may help you as well: https://android.jlelse.eu/coordinatorlayout-basic-8040c74cf426
|
Q:
sqlite returned: error code = 1, msg = near "file_theme_column": syntax error
this is my code to create database table
String sqlQueryToCreateFileTable = "create table if not exists " + TABLE_FILE + " ( " + BaseColumns._ID + " integer primary key autoincrement, "
+ COLUMN_NAME_FILE_NAME + " text not null, "
+ COLUMN_NAME_FILE_CATEGORY+ " integer not null , FOREIGN KEY ("+COLUMN_NAME_FILE_CATEGORY+") REFERENCES "+TABLE_CATEGORY+" ("+BaseColumns._ID+"), "
+ COLLUMN_NAME_FILE_THEME+ " integer not null , FOREIGN KEY ("+COLLUMN_NAME_FILE_THEME+") REFERENCES "+TABLE_THEME+" ("+BaseColumns._ID+"), "
+ COLLUMN_NAME_FILE_DATE_CREATING+ " integer not null , FOREIGN KEY ("+COLLUMN_NAME_FILE_DATE_CREATING +") REFERENCES "+TABLE_DATE+" ("+BaseColumns._ID+"), "
+ COLLUMN_NAME_FILE_CLOUD + " text default null,"
+ COLLUMN_NAME_FILE_DATE_UPLOADING + " text default null);";
db.execSQL(sqlQueryToCreateFileTable);
but I have that in the logcat
06-15 18:24:09.177: I/Process(9075): Sending signal. PID: 9075 SIG: 9
06-15 18:31:01.428: I/Database(10559): sqlite returned: error code = 1, msg = near "file_theme_column": syntax error
06-15 18:31:01.428: E/Database(10559): Failure 1 (near "file_theme_column": syntax error) on 0x5882f8 when preparing 'create table if not exists file_table ( _id integer primary key autoincrement, file_name_column text not null, file_category_column integer not null , FOREIGN KEY (file_category_column) REFERENCES category_table (_id), file_theme_column integer not null , FOREIGN KEY (file_theme_column) REFERENCES theme_table (_id), file_date_creating_column integer not null , FOREIGN KEY (file_date_creating_column) REFERENCES date_table (_id), file_cloud_column text default null,file_date_upload_column text default null);'.
06-15 18:31:01.468: D/AndroidRuntime(10559): Shutting down VM
06-15 18:31:01.468: W/dalvikvm(10559): threadid=1: thread exiting with uncaught exception (group=0x40015560)
06-15 18:31:01.488: E/AndroidRuntime(10559): FATAL EXCEPTION: main
06-15 18:31:01.488: E/AndroidRuntime(10559): android.database.sqlite.SQLiteException: near "file_theme_column": syntax error: create table if not exists file_table ( _id integer primary key autoincrement, file_name_column text not null, file_category_column integer not null , FOREIGN KEY (file_category_column) REFERENCES category_table (_id), file_theme_column integer not null , FOREIGN KEY (file_theme_column) REFERENCES theme_table (_id), file_date_creating_column integer not null , FOREIGN KEY (file_date_creating_column) REFERENCES date_table (_id), file_cloud_column text default null,file_date_upload_column text default null);
06-15 18:31:01.488: E/AndroidRuntime(10559): at android.database.sqlite.SQLiteDatabase.native_execSQL(Native Method)
06-15 18:31:01.488: E/AndroidRuntime(10559): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1763)
06-15 18:31:01.488: E/AndroidRuntime(10559): at com.app.pfe.AndroidOpenDbHelper.onCreate(AndroidOpenDbHelper.java:95)
06-15 18:31:01.488: E/AndroidRuntime(10559): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:126)
how can I fix this error?
A:
Table constraints should go to the end:
http://www.sqlite.org/lang_createtable.html
A:
Like pawelzieba said, you should try reformatting to
create table if not exists file_table (
_id integer primary key autoincrement,
file_name_column text not null,
file_category_column integer not null,
file_theme_column integer not null,
file_date_creating_column integer not null,
file_cloud_column text default null,
file_date_upload_column text default null,
FOREIGN KEY (file_category_column) REFERENCES category_table (_id),
FOREIGN KEY (file_theme_column) REFERENCES theme_table (_id),
FOREIGN KEY (file_date_creating_column) REFERENCES date_table (_id)
);
|
Eswatini Football Association
The Eswatini Football Association (EFA), formerly known as the National Football Association of Swaziland (NFAS), is the governing body of football in Eswatini. It was founded in 1968, and affiliated to FIFA in 1978 and to CAF in 1976. It organizes the national football league and the national team.
The EFA adopted its current name on 1 July 2018, during the ordinary general assembly of the national football association at the Sibane Hotel. On 11 September, the EFA announced that it will hold an event to unveil its new branding, including a new logo.
References
External links
Official site
Eswatini at the FIFA website.
Eswatini at CAF Online
Eswatini
Category:Football in Eswatini
Category:Sports governing bodies in Eswatini
Category:Sports organizations established in 1968 |
/* Generated by RuntimeBrowser
Image: /System/Library/PrivateFrameworks/AssistantServices.framework/AssistantServices
*/
@interface AFUserUtteranceSelectionResults : NSObject <NSSecureCoding> {
NSNumber * _combinedRank;
NSNumber * _combinedScore;
NSString * _interactionId;
NSNumber * _onDeviceUtterancesPresent;
NSNumber * _originalRank;
NSNumber * _originalScore;
NSString * _previousUtterance;
NSString * _sessionId;
NSString * _utteranceSource;
}
@property (nonatomic, copy) NSNumber *combinedRank;
@property (nonatomic, copy) NSNumber *combinedScore;
@property (nonatomic, copy) NSString *interactionId;
@property (nonatomic, copy) NSNumber *onDeviceUtterancesPresent;
@property (nonatomic, copy) NSNumber *originalRank;
@property (nonatomic, copy) NSNumber *originalScore;
@property (nonatomic, copy) NSString *previousUtterance;
@property (nonatomic, copy) NSString *sessionId;
@property (nonatomic, copy) NSString *utteranceSource;
+ (bool)supportsSecureCoding;
- (void).cxx_destruct;
- (id)combinedRank;
- (id)combinedScore;
- (id)description;
- (void)encodeWithCoder:(id)arg1;
- (id)initWithCoder:(id)arg1;
- (id)interactionId;
- (id)onDeviceUtterancesPresent;
- (id)originalRank;
- (id)originalScore;
- (id)previousUtterance;
- (id)sessionId;
- (void)setCombinedRank:(id)arg1;
- (void)setCombinedScore:(id)arg1;
- (void)setInteractionId:(id)arg1;
- (void)setOnDeviceUtterancesPresent:(id)arg1;
- (void)setOriginalRank:(id)arg1;
- (void)setOriginalScore:(id)arg1;
- (void)setPreviousUtterance:(id)arg1;
- (void)setSessionId:(id)arg1;
- (void)setUtteranceSource:(id)arg1;
- (id)utteranceSource;
@end
|
Related
Dyson Inc.'s new bladeless electric fan resembles anything but a fan. The company calls it an "air multiplier." To the average sci-fi enthusiast, it looks like a miniature replica of a stargate but alas, this gadget does not create a wormhole that teleports people to distant worlds. (See pictures of 50 years of the hovercraft.)
When introduced recently to students in a cafeteria at the Massachusetts Institute of Technology, the ring-shaped contraption immediately drew curious onlookers. "It's clearly a fan," said engineering student Sergei Bernstein, 18, placing his palm before the draft of cool air flowing from the circular frame. "But it looks completely different, very modern," said his friend John Berman, 17.
It's no surprise that Dyson, the company behind the bagless vacuum cleaner, would devise a bladeless fan. Since the invention of the electric fan in the late 19th century, the air-stirring apparatus has not changed in any significant way a quick Google Images search suggests that every model from the classic 1950s table fan to the industrial exhaust fan to a Batman-inspired fan has one consistent, characteristic feature: rotating blades. But Dyson did away with those, replacing them with a graceful ring set atop a cylindrical base. In essence, the device works like a vacuum cleaner in reverse. The motor in the base of the fan sucks in air and pushes it up into the ring. The air rushes out of tiny, millimeter-long slots that run along the circular frame and flows down a gently sloping ramp. As the air emerges from the ramp, it creates a circular low-pressure region that pulls in the air from behind creating a fairly uniform flow of air through the ring. (See the 25 best back-to-school gadgets.)
Conventional fans, by contrast, are messy, says Andy Samways, senior design engineer at Dyson, explaining the reasoning behind this latest invention. "In a regular fan, the blade is chopping the air up and hurling the packets of air [at you]," he says. The Dyson Air Multiplier bathes users in a constant cool breeze. (See the best inventions of 2008.)
But despite its striking looks (compared with a dusty box fan fished out of the basement, the Dyson product could pass for sculpture) and gracious soundlessness (the machine emits a gentle hiss, no louder than the air conditioner in your car), it's hard to see how the new fan is a functional improvement over age-old models. While Dyson's past inventions such as the bagless vac and the ultra-high-speed hand dryer significantly enhanced the performance of those devices, the Air Multiplier doesn't exactly make a quantum leap in terms of its primary function, cooling. (On a sweltering day, even "packets of air" can be glorious.) On top of that, the Dyson fan carries a whopping $300 to $330 price tag.
Because there are no outwardly moving parts, however, it's safer for children. At 3.5 lb., it's also eminently portable. And even though the plastic shell looks delicate, Dyson's engineers claim that the product has survived test drops from stairwells and tables. In short, it has all the characteristics of a new gadget that can be copied and mass-produced in some Chinese factory for hundreds of dollars less. But before you set your sights on a bootleg version, Samways says that the Air Multiplier's deceivingly simple structure is the result of a laborious design process that can't be easily copied. "We have many patents on this [fan], on the impeller, aerofoil and product development," he says. Whether those patents can stand up to the sheer bureaucracy of enforcing them in China remains to be seen.
For now, though, the bladeless fan will cost as much as a couple of weeks' worth of groceries. That's a prohibitively steep price for many Americans in simple need of a fan. So may we suggest that Dyson entice buyers by throwing in the wormhole attachment? |
In memory of John Neville: “Munchausen vs. the Aliens”
John Neville, who played Romeo to Claire Bloom’s Juliet, Hamlet to Judi Dench’s Ophelia and Othello to Richard Burton’s Iago (and vice versa), but who may be best known in the United States as the title character in the exuberantly loopy film “The Adventures of Baron Munchausen” and a recurring one in the television series “The X-Files,” died in Toronto on Saturday. He was 86.
The Adventures of Baron Munchausen may not be the best film ever made, but it’s hands-down my favorite movie. That was true even in the 1990s, when John Neville began appearing on The X-Files. I remember my first delighted exclamation on spotting him in the tailored suit of a Man in Black: “That’s Baron Munchausen!”
I wrote the following poem as a way of reconciling Neville’s best-known roles in my own head. It appeared in the late, lamented Talebones and in my collections Defacing the Moon and The Journey to Kailash. Now I offer it in tribute to a great, and under-celebrated, entertainer, along with the collage I created to illustrate it.
Munchausen vs. the Aliens
Urban legends encounter urbane liar,
tractor-beam him
right off his five-winged pegasus;
five oval grey heads
roll at saber-flicks,
before they clamp the Baron down,
pierce him in place,
spread him open.
His cavities issue
oily polygonal beasts
too wily to be
imprisoned in specimen jars.
His vivisection completed,
he thanks greys with grace,
folds them with their saucer
into imaginary space,
sealed forever inside
a tale he spins
beside the hearth-light. |
Michael Costantino wants the TSA to know he can perform the tasks required of him, even though he was born without a right hand. (Photo: CBS 2)
NEW YORK (CBSNewYork) — A former boxer says he’s been sucker-punched by the Transportation Security Administration.
He was born with one hand, which didn’t stop him from fighting in the Golden Gloves, but the TSA says he’s not qualified for a job as a security screener.
Now he’s filing a discrimination complaint.
“I was pretty depressed, but it’s the government. I was like, what am I going to do?” Michael Costantino told CBS 2’s Tony Aiello.
The 32-year-old Queens resident said he didn’t see it coming. He applied for work as a TSA security officer, passed the background check, aced the online exam and finished the interview process.
Then the TSA sent him a letter — rejecting his application — because Costantino was born missing his right hand.
“I know I’m more than capable of doing the job, and I passed everything that was required of me,” Costantino told 1010 WINS. “They stated in a letter that I couldn’t do certain tasks that I do in everyday life.”
His disability didn’t stop him from success as an amateur boxer, but the TSA says without two hands he can’t effectively examine luggage or pat-down passengers.
Costantino said the TSA is making a huge assumption.
“Whatever was stated in the medical report didn’t have anything to do with the testing, it was never part of the test for the job,” Costantino told 1010 WINS. “They basically just assumed, because I was born without a right hand, that I would not be able to perform certain tasks.
“They never asked me to open any luggage, lockets, zippers … it was never done during the job interview process.”
The TSA didn’t ask, but Aiello did. Costantino had no trouble opening a zipper, undoing a Ziploc or opening child-proof pill bottles.
When asked if that kind of test should be the TSA’s standard, Costantino said, “Yes, I agree with that.”
Lawyer Jonathan Bell has filed a complaint with the TSA and appealed his case to the Equal Employment Opportunity Commission.
“That’s why we’re here today. They did absolutely nothing to test whether or not he can perform the essential functions of the job,” Bell said.
The agency said it’s committed to hiring the disabled, but “mission-critical occupations include strict physical and medical requirements” that Costantino just doesn’t meet.
Costantino said he learned one thing as a boxer — stand your ground, keep on going and don’t back down.
So, he’s ready to go toe to toe with the TSA.
The TSA suggested Costantino might still qualify for other positions within the agency or other federal jobs.
Do you think the TSA was correct in its ruling? Let us know below… |
Analysis of the brain-stem white-matter tracts with diffusion tensor imaging.
The authors have reviewed the diffusion tensor imaging (DTI) of the brain stem in 19 subjects, consisting of 15 normal volunteers and four multi-system atrophy patients. The study was performed with 1.5 T MRI scanners. DTI was correlated with an automated program allowing superposition of the structural anatomy. Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus. Smaller fibers, such as medial longitudinal fascicles and central tegmental tracts are difficult to visualize. To identify the anatomical orientation of the brain stem, white-matter fibers will help us understand the different functional disease processes, and DTI will play an important role for the evaluation of the different white matter fibers in the brain stem. |
A Decade of Experience in Primary Prevention of Clostridium difficile Infection at a Community Hospital Using the Probiotic Combination Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+).
In August 2003, the 284-bed community hospital Pierre-Le Gardeur (PLGH) in Quebec experienced a major outbreak associated with the Clostridium difficile NAP1/027/BI strain. Augmented standard preventive measures (SPMs) were not able to control this outbreak. It was decided in February 2004 to give to every adult inpatient on antibiotics, without any exclusion, a probiotic (Bio-K+: Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2) within 12 hours of the antibiotic prescription. Augmented SPMs were continued. The use of the probiotic in addition to SPMs was associated with a marked reduction of C. difficile infection (CDI). During the 10 years of observation, 44 835 inpatients received Bio-K+, and the CDI rate at PLGH declined from 18.0 cases per 10,000 patient-days and remained at low mean levels of 2.3 cases per 10,000 patient-days. Additionally, 10-year data collected by the Ministry of Health in Quebec comparing the CDI rate between Quebec hospitals showed that CDI rates at PLGH were consistently and continuously lower compared with those at similar hospitals. Blood cultures were monitored at PLGH for Lactobacillus bacteremia through the 10 years' experience, and no Lactobacillus bacteremias were detected. Despite the limitation of an observational study, we concluded that the probiotic Bio-K+ was safe and effective in decreasing our primary CDI rate. |
Spellbinding and crooning: sound amplification, radio, and political rhetoric in international comparative perspective, 1900-1945.
This article researches in an interdisciplinary way the relationship of sound technology and political culture at the beginning of the twentieth century. It sketches the different strategies that politicians--Franklin D. Roosevelt, Adolf Hitler, Winston Churchill, and Dutch prime minister Hendrikus Colijn--found for the challenges that sound amplification and radio created for their rhetoric and presentation. Taking their different political styles into account, the article demonstrates that the interconnected technologies of sound amplification and radio forced a transition from a spellbinding style based on atmosphere and pathos in a virtual environment to "political crooning" that created artificial intimacy in despatialized simultaneity. Roosevelt and Colijn created the best examples of this political crooning, while Churchill and Hitler encountered problems in this respect. Churchill's radio successes profited from the special circumstances during the first period of World War II. Hitler's speeches were integrated into a radio regime trying to shape, with dictatorial powers, a national socialistic community of listeners. |
Tennessee economy to improve more in 2017 but U.S. growth rate may exceed Volunteer State growth
Tennessee economy to improve more in 2017 but U.S. growth rate may exceed Volunteer State growth
Matt Murray, associate director of the Center for Business and Economic Reasearch of the University of Tennessee speaks at the Chattanooga Manufacturers Association annual meeting at the Chattanooga Convention Center Wednesday.
Matt Murray, associate director of the Center for...
Photo by
Ashlie White
Document: Read the Tennessee economic outlook for 2017
Read the Tennessee economic outlook for 2017
Despite an increase in the local jobless rate last month, Tennessee's economy should continue to improve this year and next, keeping the jobless rate below 5 percent and giving most workers their biggest wage increases in years.
"We saw as 2016 closed out, wage rates rising at a faster pace, and I would expect that to continue for at least the next couple of years," said Matt Murray, associate director of the Boyd Center for Business and Economic Research at the University of Tennessee, which released its annual economic forecast Thursday. "Tight labor markets are going to contribute to further rises in average hourly earnings. Wages have been stagnant since the Great Recession, so these increases should be really good news for American workers."
Murray and other UT economists predict employment in Tennessee will grow another 1.4 percent this year and 1.2 percent next year. Although slower than the job growth in 2016, the employment gains this year should keep Tennessee's unemployment rate to an average of 4.8 percent in 2017 and 4.6 percent next year, even as the population of the state continues to grow.
Murray said higher interest rates, inflation and exchange rates could limit some growth in the next year.
"But I don't see anything short of some unexpected shock that would derail another year of growth," Murray said.
Over the next 10 years, Tennessee's population is projected to grow at a rate of 1 percent per year, matching the forecast population growth of the nation.
The Tennessee Department of Labor and Workforce Development reported Thursday that unemployment edged higher in both metropolitan Chattanooga and Cleveland, Tenn., last month as employment shrank at the end of 2016 across Southeast Tennessee.
Chattanooga's jobless rate rose by two tenths of a percentage point to 5 percent, topping the U.S. jobless rate. The number of employed Chattanoogans fell last month by 2,220 workers as the Christmas holidays approached and more workers were idled or their jobs phased out.
In metro Cleveland, unemployment rose by three tenths of a percentage point to 4.4 percent, with a drop of 880 jobs at the end of the year.
Metro Cleveland has led the state in job growth for most of 2016, and the Cleveland area continued to have a jobless rate below the comparable, non-seasonally adjusted rate of 4.9 percent last month across all of Tennessee.
Tennessee's jobless rate rose from the springtime low of 4.1 percent reached last April to end the year at 4.9 percent.
Across the Volunteer State, the jobless rate was lowest last month in Williamson County at 3.5 percent and highest in Clay County at 7.4 percent.
In the Chattanooga region, unemployment was lowest in Bradley County at 4.2 percent and highest in Rhea County at 9 percent.
Contact Dave Flessner at dflessner@timesfreepress.com or at 423-757-6340.
Jobless in December
Tennessee — 4.9 percent, up 0.3 percent
- Bradley — 4.2 percent, up 0.2 percent
- Hamilton — 4.8 percent up 0.2 percent
- Coffee — 4.9 percent, up 0.2 percent
- Franklin — 5.3 percent, up 0.3 percent
- McMinn — 5.6 percent, up 0.3 percent
- Polk — 5.8 percent, up 0.7 percent
- Sequatchie — 6.1 percent, up 0.4 percent
- Marion — 6.5 percent, up 0.2 percent
- Meigs — 6.7 percent, up 0.4 percent
- Grundy — 7.3 percent, up 0.4 percent
- Bledsoe — 7.6 percent, up 0.9 percent
- Rhea — 9 percent, up 1.2 percent
Georgia — 5.2 percent, up 0.2 percent
- Catoosa — 4.7 percent, up 0.2 percent
- Dade — 5.1 percent, up 0.2 percent
- Walker — 5.3 percent, up 0.3 percent
- Whitfield — 5.7 percent, up 0.1 percent
- Chattooga — 6.1 percent, up 0.4 percent
Sources: Tennessee Department of Labor and Workforce Development and the Georgia Department of Labor |
Q:
Going around finding a signature used in a .APK file
So I've decompiled an APK and I believe that I have now is the source code (most with a bunch of random variables and method names, but from what I've read this is completely normal)
the app in question uses a signature in the registration request that changes everytime, this signature is not received from any request preceding it so I assume the only way to find out how this is being generated is through the APK. Do you guys have any direction on where exactly I should be looking?
A:
The signature is likely a hash based on some string value and the current date (potentially milliseconds since the epoch). This question is impossible to answer without the source code, but try looking in the code for any references to constant string values and references to Time() or Calendar().
|
Ferritin effect on the transverse relaxation of water: NMR microscopy at 9.4 T.
Accumulation of ferritin, the iron storage protein, has been linked recently to aging and a number of pathologies. Noninvasive detection of iron storage by MRI relies on its extremely strong effect on water relaxation. The aim of this article is to characterize the effect of ferritin on transverse water relaxation in a high magnetic field, using an imaging Carr-Purcell Meiboom-Gill (CPMG) preparation sequence. Ferritin-induced water relaxation showed quadratic dependence on the iron loading factor, implying a paramagnetic mechanism. However, an additional zero order term was found, that could be due to the initial stages of the iron core loading. Significant enhancement of ferritin contrast was obtained at very short Tau CPMG durations. This approach for enhancing ferritin contrast was demonstrated by NMR microscopy of ferritin-injected Xenopus oocytes, thus showing the feasibility of ferritin detection in a high magnetic field, even in systems with short transverse relaxation. |
Birkett Pribble
Birkett Lee Pribble (August 25, 1897 – December 24, 1987) was a college football player. He was a guard for the Kentucky Wildcats, selected All-Southern in 1922. The 1922 team beat Alabama.
References
Category:1897 births
Category:1987 deaths
Category:People from Pendleton County, Kentucky
Category:All-Southern college football players
Category:Players of American football from Kentucky
Category:American football guards
Category:Kentucky Wildcats football players |
Q:
redirect to requested page after login using PHP function
i have a function that echo $_SESSION value in login page and store $_SERVER['REQUEST_URI'] as $_SESSION value on other page and it works fine.
But i need to call redirect_after_login function in all product page so i just added line after redirect_after_login
So my function.php file will look link this
<?php
session_start();
$key = '';
function redirect_after_login($value) {
if (!empty($value)) {
echo $_SESSION['url'];
} else {
echo $_SESSION['url'] = $_SERVER['REQUEST_URI'];
}
}
$activate_finction = $key == true ? 'Yes' : '';
$url = redirect_after_login($activate_finction);
And in login.php i added
$key .= 'login';//calling redirect function with value so it should send session value
if (isset($_POST['submit'])) {
// login function skipped it....
header('location:' . $url);
exit;
} else {
$error[] = 'Wrong username or password or your account has not been activated.';
}
}
Since $key .= 'login'; has value
$activate_finction = $key == true ? 'Yes' : '';
$url = redirect_after_login($activate_finction);
Function is now called with ==true so i should receive stored value but still i get requested_url
My problem is
in all page i get $_SESSION['url'] = $_SERVER['REQUEST_URI']; this value.
How do i get session value login.php and in all product pages function should store requested_url as session value.
A:
I refactor the code, so here you are a complete example:
function.php:
<?php
session_start();
if (isset($_SERVER['HTTP_REFERER']) && basename($_SERVER['HTTP_REFERER']) != basename($_SERVER['PHP_SELF'])) {
$_SESSION['url'] = $_SERVER['HTTP_REFERER'];
}
function redirect_after_login() {
header('Location:' . $_SESSION['url']);
}
?>
product.php:
<?php
include "function.php";
?>
<html>
<head></head>
<body>
This is <?php echo $_SERVER['PHP_SELF']; ?> file.<br><br>
<input type="button" name="login" value="Login" onclick="location.href='login.php'">
</body>
</html>
login.php
<?php
include "function.php";
if(isset($_POST['submit'])){
if($_POST['username'] == 1 && $_POST['password'] == 1){
//success
$_SESSION['logged'] = 1;
redirect_after_login();
}else{
//error
$_SESSION['logged'] = 0;
$error = 'Wrong username or password';
}
}else{
unset($error);
}
?>
<html>
<head></head>
<body>
This is <?php echo $_SERVER['PHP_SELF']; ?> file.<br><br>
<form method="post" action="login.php">
User: <input type="text" name="username"><br>
Pass: <input type="password" name="password"><br>
<input type="submit" name="submit" value="Login">
</form>
<?php
if(isset($error)) echo "ERROR:" .$error;
?>
</body>
</html>
Some short explanations:
to test the redirect logic, you can load product.php?id=258 initially;
$_SESSION['url'] is keeping HTTP_REFERER - the page you are coming from;
login.php is calling redirect_after_login() function on successful login (currently with user:1/pass:1, just for the example)
on successful login, there is an addition SESSION variable logged which you can use further (like to hide LOGIN button onto product.php page)
on bad login, there is an error displayed, but you the user stays on login screen.
$_SESSION['url'] is overwritten every time when you are visiting a different page and only then. This prevents losing HTTP_REFERER in case of bad login (when you have an actual refresh and HTTP_REFERER becomes the page itself)
Hope this helps.
|
Q:
Continuity of restriction map
Consider a map $f:X\rightarrow Y$ and suppose $X=\bigcup_i U_i$ is a union of open subsets. Prove that if all the restrictions $f_i=f|_{U_i}:U_i\rightarrow Y$ are continuous, then $f$ is continuous.
Proof: For any $U$ open in $Y$, we have $f_i^{-1}(U)$ is open in $U_i$ by assumption. Hence $f_i^{-1}(U)=U_i \cap V$ for some open set $V$ in X. Since $U_i$ is open in $X$, we have $f_i^{-1}(U)$ is open in $X$. But then we also have $f_i^{-1}(U)=f^{-1}(U) \cap U_i$, hence
$$f^{-1}(U)=f^{-1}(U)\cap X = f^{-1}(U) \cap \bigcup_i U_i= \bigcup_i f^{-1}(U)\cap U_i=\bigcup_i f_i^{-1}(U)$$
is a union of open sets, hence open.
My question is, why can't we just say $V=f^{-1}(U)$? If $A \cap B = C \cap B$, does it implies $A=C$? Thanks for answering
A:
In general it is not true that if $A\cap B=C\cap B$ then $A=C$. For example, let $A=\{1,2,3,4\}$, $C=\{2,50,800\}$, and $B=\{2\}$. Then $A\cap B=\{2\}=C\cap B$, but clearly $A\not= C$. This is why you cannot conclude that $V=f^{-1}(U)$.
|
Whitaker refuses to testify unless Dems drop subpoena threat
Thursday
Feb 7, 2019 at 5:58 PMFeb 7, 2019 at 5:58 PM
By Mary Clare Jalonick & Eric TuckerAssociated Press
WASHINGTON — Acting Attorney General Matthew Whitaker said Thursday that he won't appear before Congress unless a House committee drops its threat of a subpoena for his testimony, calling the Democratic-led move an act of "political theater."
The statement from Whitaker came soon after the House Judiciary Committee approved a tentative subpoena for Whitaker in an effort to ensure that he appears at a scheduled hearing Friday and answers questions.
The vote doesn't issue a subpoena to Whitaker but allows the committee chairman, Rep. Jerrold Nadler, to do so if Whitaker is uncooperative. Nadler said he hopes not to have to use the subpoena, but "a series of troubling events over the past few months suggest that we should be prepared."
Nadler, a New York Democrat, said that as late as last week the committee had received reports that some at the department were counseling Whitaker not to appear.
Whitaker insisted Thursday that that was not the case, saying he had "devoted considerable resources and numerous hours to my preparation" and was looking forward to the hearing. He criticized the committee for prematurely and unnecessarily authorizing a subpoena for him even though he had agreed to appear.
"Based upon today's action, it is apparent that the Committee's true intention is not to discuss the great work of the Department of Justice, but to create a public spectacle. Political theater is not the purpose of an oversight hearing, and I will not allow that to be the case," he added.
Democrats have said they want to talk to Whitaker because he is a close ally of President Donald Trump who has criticized special counsel Robert Mueller's Russia investigation, which he oversees. They are calling him to testify even though his time leading the Justice Department is coming to a close, with the Senate expected this month to confirm Trump's nominee for attorney general, William Barr. The Senate Judiciary Committee voted along party lines Thursday to approve Barr's nomination, sending the pick to the full Senate.
Nadler's resolution to approve a subpoena if necessary was met with strong opposition from Republicans. They said it was unnecessary because Whitaker was already appearing voluntarily.
Georgia Rep. Doug Collins, the top Republican on the panel, also called the subpoena authorization "political theater" before the vote. Collins said it was "choreographed by the chairman and starring the acting attorney general as some mythological protector of secrets."
After Whitaker's statement, Collins said Nadler had overplayed his hand.
"In a quest to score political points against the president, they authorized a pre-emptive subpoena, treating a voluntary witness as hostile," Collins said.
In a separate letter sent to Nadler, Assistant Attorney General Stephen Boyd wrote that the department expects a response from Nadler by Thursday evening. Boyd also responded to Nadler's request for notification if Whitaker planned to assert executive privilege on certain topics.
Boyd laid out an argument for asserting such executive privilege in the letter, saying that administration officials from both parties have declined to answer questions about conversations they have had with the president.
"Rather than conducting appropriate oversight into the department's programs and activities, the committee evidently seeks to ask questions about confidential presidential communications that no attorney general could ever be expected to disclose under the circumstances," Boyd wrote.
Nadler had noted that previous Trump administration officials, including former Attorney General Jeff Sessions, declined to answer questions about conversations with the White House during testimony, saying that the president might want to claim executive privilege on those conversations in the future. Nadler said that is "ridiculous" and administration officials must provide the committee with answers or a better excuse to withhold them.
"Without the threat of a subpoena, I believe it may be difficult to hold Mr. Whitaker to this standard," Nadler said.
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Working towards an inclusive curriculum.
The move towards an inclusive model of education presents teachers with the difficulty of differentiating the curriculum for children with speech, language and communication impairments. This paper focuses on the 'WiSaLT Curriculum Appendix'-a tool which can be used by teachers and speech and language therapists to help such children access the mainstream curriculum and to promote improvement in their language and communication skills. As well as highlighting potential areas of difficulty within each attainment target for key stage one, the appendix guides users to specific strategies and activities. Thus the speech and language therapist and teacher can identify which attainment targets might prove problematic for any one child and also have access to ideas which can help. |
Run and monitor a container
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On a production server, you'll want to run the container in the background. In this video, learn how to use the -d flag to run the container as a background process, and how to use docker ps to monitor the status of running containers.
- [Instructor] On a real server,…you'll wanna run the container,…or multiple containers as background processes.…If we use Docker run with the -d flag,…it'll start the container in the background.…We still need -p to map the ports…from inside the container to our local machine,…and we'll specify the name of the image to start up.…We can use Docker ps to monitor the status…of this running container.…The output of Docker ps is usually too wide…for a single window, so I like to use the --format command…to make it a little bit easier to read.…
I prefer using table .names .image .status, and. ports,…this just customizes what output Docker ps…will send to the screen.…So that's a little bit more readable.…This tells us that this image, HelloCoreWorld…was spun up into the container called hungry_kare,…it's been up for about 40 seconds,…and it has internal port 5000 mapped to external port 5000.…
We can use Docker ps to monitor the status…of this container, or we can use Docker stop,…followed by the generated container name,…
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Released
9/12/2018
Learn how to deploy cross-platform ASP.NET Core applications. With the changes to ASP.NET Core that allow apps to run across Mac, Windows, and Linux, developers need to be able to choose the right deployment strategy: one that maximizes app performance and user experience. This course helps you deploy ASP.NET apps to IIS and cloud services like Azure, as well as to Linux servers and Docker containers. Follow along with Nate Barbettini as he sets up a simple project and works through these different deployment scenarios. Get practical tips and insights into the pros and cons of each deployment option. Plus, find out how Docker Hub can make it even easier to distribute your images across machines. |
Malawian women protest over 'trouser attacks'
Women held up a sign saying: "Real men don't bother women"
Continue reading the main story Related Stories
Hundreds of people have protested in Blantyre in Malawi about attacks on women for wearing trousers.
Some women were this week beaten and stripped by vendors on the streets of the capital, Lilongwe, and Blantyre for not wearing traditional dress.
A BBC reporter says women wore trousers and mini-skirts to the demonstration to show their outrage.
President Bingu wa Mutharika has said on national radio that women had the right to wear what they want.
He denied reports that he had ordered women to stop wearing trousers, and ordered anyone harassing women to be arrested.
Until 1994, women in the deeply conservative southern African country were banned from wearing trousers or mini-skirts under the autocratic rule of Hastings Banda.
Men were also banned from having long hair.
Women have also been attacked for wearing trousers in Kenya, South Africa and Zimbabwe in recent years.
'Abominable'
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The BBC's Raphael Tenthani in Blantyre says Vice-President Joyce Banda, the gender minister, several MPs, church leaders, university lecturers and other activists attended Friday's protest.
One sign was held up during the gathering with the words: "Real men don't bother women" and some of the women wore white T-shirts saying: "Vendor: Today I buy from you, tomorrow you undress me?"
"The reason why I'm here is because I'm in total disbelief that in the year 2012 women are being stripped naked," Ms Banda told the BBC at the vigil.
Speaker after speaker condemned the harassment of women, saying Malawi could not afford to turn back the clock, our correspondent says.
Continue reading the main story “ Start Quote Women who want to wear trousers should do so, as you will be protected from thugs, vendors and terrorists” End Quote Bingu wa Mutharika President
"Trousers and mini-skirts for most women in Malawi is a symbol for our hard-won freedom from the one-party dictatorship to the multiparty era," one woman said.
"Therefore it has been a shock... that 18 years after that multiparty [era began] we can sit here and talk about women being undressed in town. It's abominable."
Our correspondent says men and boys also attended the event where there was dancing and singing, with the Bob Marley classic No Woman No Cry getting the loudest cheers.
A vendors' representative at the protest, Innocent Mussa, was booed off the stage by the women, he says.
"I'm ashamed to be associated with the stripping naked of innocent women," Mr Mussa told the crowd.
"Those were acts of thugs, because a true vendor would want to sell his wares to women, he can't be harassing potential customers," he said.
Seodi White, a lawyer and leading women's rights activist and protest organiser, said the women were being targeted by disaffected youth unhappy with the economic situation.
"Is this really about culture or something else in terms of economic hardship people are looking for an outlet to vent on?," she told the BBC's Network Africa programme.
Earlier, Mrs Banda also blamed the attacks on economic woes in Malawi, where there are severe shortages of fuel and foreign currency at present.
"There is so much suffering that people have decided to vent their frustrations on each other," the vice-president said.
Last year, the UK and other donors cut aid to Malawi, amid criticism of its economic policies and its attitude to the opposition and journalists.
President Mutharika on Thursday made a nationwide broadcast, calling for an end to the attacks.
"I will not allow anyone to... go on the streets and start undressing women and girls wearing trousers, because that is illegal," he said.
"You are free to wear what you want. Women who want to wear trousers should do so, as you will be protected from thugs, vendors and terrorists." |
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Apartment of 120m2 ground floor and 1 apartment on the 1st floor of 60m2 with living room, dining room, a fully equipped kitchen, 2 bedrooms and 2 bathrooms
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If you like the beach and want to relax, this is the place to spend your holidays. Come discover one of the most beautiful beaches of the sandy Algarve with over 14km long. Ideal for family and come to rest. |
Tarot Symbolism: No one is here….
People in the cards of a Tarot deck serve to focus the attention. They may signify the querent, or other people in the querent’s life who have a say in the event which is under consideration. They may signify possibilities for the querent. Always, they help in understanding what is, or what has to be, in a given context.
Thus, it is utterly fascinating for me, when a card has nobody in it…!
In the Rider-Waite deck, there are just two cards with no one… the Three of Swords and the Eight of Wands.
All the Aces have a hand holding the symbol of the suit, signifying a start, a step to begin, a root for manifesting the power of the suit. Each and every one of the Major Arcana are peopled… yes, even The Moon has the unbirthed Man in the Moon! And according to the Tree of Life, what you don’t have is as important in shaping your perspective as what is in your face….
The Three of Swords holds a bleak vision, if we would go by our trained mind. A symbolic heart (and this is what makes it unconnected to any person) is pierced through by three swords of such overwhelming weightage that the mere visual can invoke pity. The background contributes to the bleakness… colourless, cloudy, lashing sleet. And the perfectly symmetrical symbolic heart hangs in the middle of nowhere, stabbed yet not bleeding.
In contrast, the Eight of Wands looks uplifting. Again, though our trained powers of observation, we see a bunch of eight wands up in the air… above our heads, as it would seem from the distant hills. They have apparent direction, but no apparent control exerted by any human. And also the height of their displacement makes the action of the flying wands disconnected from humans. The light in the scene is clear and strong, and the perspective is wide open.
To me, here is the connect….
Lack of people symbolises times when we have no control over the situation. It could be that we have taken some action earlier, and the consequences have been ripped out of our hands. Or it could also be that the basis of our action had been assumptions… which is a case of immaturity, and thus, we feel no connection to what is happening now. Else, and more significantly, it could be the moment when we have the opportunity to realise that we have far greater creative powers over our lives than we are willing to believe.
Nobody has broken anybody’s heart in the Three of Swords. It is a heart one has imagined…. It is an emotional box that one has defined through preferrences and dislikes. It is what we ‘think’ is our heart, and not what actually is. Thus, what is injured is an idea, a perception…. and not love. When our hearts break…. it is really not our ‘heart’ breaking. Our capacity to love is divine. Nothing destroys the divine. But our assumptions and our desires to be treated in a particular way because we are comfortable with it form an armour of egg-shells… threatened at every turn. And what more exemplary proof of that threat than the sword!!! We are easiest hurt by the words of others, whereas we need to be mature enough to realise that people speak their truth, not ours. We are just as liable to poke at other people’s ideas of self-importance, too! So, with Three of Swords, we meet our emotional immaturity and we have the opportunity to be thankful that those prods could grow us up in a hurry!
The Eight of Wands talks about our desire to control our lives being wrested out of our grip, and we are forced to learn… trust. It is when we are at our most passionate that we have the hardest grips. Nobody knows better than ourselves! And particularly, up until the previous card of Seven of Wands, we were striving, battling, pitting and pitching… and winning. We know what to do, and we are good at how to do it, right? Wrong. No matter how much you know, the divine always knows more. Indeed, in following our passion, we have chosen to be in the flow, and then, there comes a moment when it is only the flow. Trying to regain control would be a mistake… a huge one. It would only speak of fear. Letting be, letting go, letting God… That is the Eight of Wands!
When one or the other of these cards appear in a reading I am participating in, I realise that the querent stands at a threshold of growth… where he is being made to (yes, perhaps even forced to) drop his self-image and let in his divine image of far greater potential than he could imagine.
Comments
I like what you said about the 3 of Swords- a card I have previously regarded with a certain amount of loathing. I had always considered it to be the “vicious gossip behind one’s back” card.
It strikes me that it’s a great card for representing the proverbial reality check, accompanied by the pang one experiences when they realize they need to check that reality, and make the (often uncomfortable) adjustments to their world-view as well as to their actions and life-style.
“Lack of people symbolises times when we have no control over the situation” is a pretty good approximation. In the Crowley-Harris version of The Number Cards, there are no people apparent whatsoever. I consider The Pips as so-called “blind forces”, truly elemental in that they apply to all life-forms. The Trump series describes a process “uniquely human”.
By the way, definite “persons” begin to disappear as the Trump series escallates, until Little Children dancing under The Sun!
Indeed, Odyn, yes! 🙂
I have seen that whether they contain people or not, the pips do end up being very uni-dimensionally forceful!
Ah, yes… people do disappear, and are born again, before they decide to so all by themselves. That is lovely, Odyn! Thank you!
Warm regards,
Mohini
joie de vivre ˌʒwɑː də ˈviːvr(ə),French ʒwad vivʀ/ noun: exuberant enjoyment of life. What better way to start off 2016 than with a new deck! Hop along in this Tarot Professionals Blog-Hop by following the links below: Thanks to Fiona Benjamin for organising the TP blog-hop, hopefully the first of many monthly hops to come. Previous blog Master List […]
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Quotes
We think God is only ‘good’ or ‘just.’ God is everything, everywhere. Nothing can exist without the particle we call God. When we see that there is no division, no lack, no right or wrong, we recognise the splendour of unity, the wonder of oneness. Then we begin to recognise ourselves as God. However, it is our destiny to always seek divinity just as we are divinity, therein lies the great paradox. - JbR 2014 |
Effect of incision location on preoperative oblique astigmatism after scleral tunnel incision.
To evaluate the effect of incision location or clinically relevant preoperative oblique astigmatism. Department of Ophthalmology, Virchow Medical Center, Humboldt-University, Berlin, Germany. This prospective study included 68 patients who had phacoemulsification and posterior chamber lens implantation using a standardized 7.0 mm self-sealing trapezoidal scleral tunnel incision. Each patient was randomly assigned to one of three incision locations: Group A, conventional superior incision; Group B, temporal incision; Group C, oblique incision centered on the steeper meridian (modified BENT incision). Astigmatism analysis was performed by manual keratometry and corneal topography. A significant mean reduction in astigmatism of 0.58 diopter (D) (P < .01) was achieved in only the modified BENT incision group. Postoperatively, significant flattening of 0.27 D (P < .01) in the steeper meridian as well as steepening of 0.29 D (P < .01) in the flatter meridian occurred. No decrease in astigmatism was noted in the superior or temporal incision groups. Five months postoperatively, vector analysis showed that surgically induced astigmatism was significantly higher in the superior incision group (1.16 D +/- 0.44 [SD]) than in the temporal incision group (0.66 +/- 0.32 D) or modified BENT incision group (0.82 +/- 0.50 D). Corneal topographic analysis confirmed these results within +/- 0.3 D. Only the oblique incision centered on the steeper meridian (modified BENT incision) effectively and predictably reduced preoperative oblique astigmatism. In eyes with clinically relevant oblique astigmatism, we recommend using a modified BENT incision. |
Fantastic home on Lake Pagosa . 4 bedroom 4 bathroom, living room, den and family room with walkout to the lake. Bring your battle boards or fish off the shore. This is a perfect family retreat or great rental property. Stucco exterior for easy low maintenance, concrete driveway, in floor heat, fireplace in living room and lots of room for entertaining on the deck or playing games in the recreation room..... a must see...
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Hereditary abductor vocal cord paralysis.
Familial bilateral abductor cord paralysis was described in the father and two sons of a family in which the ramaining siblings (obe boy and three girls) were normal. The onset of stridor ranged from six months to nine years after birth in these patients who were all treated with a tracheostomy. Normal development and intelligence was experienced by all three patients. Since previous reports of hereditary abductor cord paralysis described mental retardation in all patients who were maintained without tracheostomy, anoxia from unrelieved laryngeal obstruction may be a significant complication following nonsurgical management of patients who appear to tolerate bilateral abductor vocal cord paralysis. |
This is a NEAT idea if anyone wants a fun project.
That also knows how to write some DSP software:
Imagine an APRS product that works like this:
Imagine wearing a pair of headphones.
Close your eyes and face north.
When an APRS user with a D7 HT speaks,
You HEAR him in the direction where he is.
If he is to the East, you hear him to the right.
If he is to the west, you hear him to your left.
Anywhere in between, and the earphones are phased so that you
hear his direction.
Now, too bad the APRS PTT mode does not put the position data at
the FRONT of a packet, but at the end. At the front, you could
know who is talking from where and you could then phase delay
his voice to create the correct virtual postion. But it isnt.
The packet is at the end.
So, given this end-PTT limitation, then here is how I would
implement this and it also makes it simpler.
1) Pass the voice through both earphones in MONO.
2) When the PTT mode packet comes in
3) Send a "roger-beep" to the earphones.
(A) Phased to indicate direction
(B) Tone frequency to indicate distance.
High tone means close. Low tone means far. Any other tone
inbetween...
Once that is working, make it proportional to own-heading, and
now you can "see APRS in the dark"...
Bob, WB4APR |
C5b-9 and interleukin-6 in chronic hepatitis C. Surrogate markers predicting short-term response to interferon alpha-2b.
Available data and our observations suggest that elevated levels of interleukin (IL)-6 and -10 and some complement parameters may be associated with a poor response to IFN alpha. We evaluated how baseline levels of C5b-9, IL-6, and IL-10 influence the outcome of IFN alpha treatment. Fifty-one patients with established chronic hepatitis C were enrolled and treated with IFN alpha-2b. Before and after a 12-week-IFN-treatment (3 MU or 5 MU tiw) serum levels of IL-6, IL-10, C5b-9 and RNA of hepatitis C virus (HCV) were assessed. Sera of 46 sex- and age-matched, healthy blood donors served as control. While two-thirds of patients was considered 'responder', 14 patients had no significant decrease either in HCV RNA or in ALT levels. In the responder's group lower baseline levels of IL-6 and C5b-9 were found than those in the 'non-responder' group. As a result of IFN therapy HCV RNA and C5b-9 levels significantly decreased. While the serum concentration of IL-6 increased during the follow-up period, regarding IL-10, no change was observed. In patients with 'low' baseline levels of C5b-9 (<2053 ng/ml) IFN alpha resulted in a significantly (P = 0.0005) higher decrease in HCV RNA level. Regarding 'low' IL-6 values (< 1.47 pg/ml) similar but somewhat less significant (P = 0.0039) difference was found if the change of HCV RNA was investigated. The odds ratio of patients with low IL-6 and/or C5b-9 to responding to IFN alpha treatment was almost 10 times (CI: 9.1 (1.8-50.9)) higher as compared with patients without 'low' levels of these parameters. Our data suggest that serum level(s) of IL-6 and/or C5b-9 taken prior to the initiation of IFN treatment may serve as surrogate marker(s) in evaluating patients with chronic hepatitis C whether to get IFN alpha in monotherapy or to consider having combination therapy in the form of IFN alpha-ribavirin. |
Robin Williams dead after apparent suicide
Actor Robin Williams was found dead inside his home in Northern California on Monday. The Marin County Sheriff’s Department confirmed that Williams, 63, has passed away.
While an investigation is still ongoing, authorities believe Williams committed suicide. He was found unconscious and experts suspect he took his own life by way of asphyxia.
Williams checked into rehab last month and was said to be struggling with depression. He battled drug and alcohol addiction in the 1980s but said he had been sober for more than 20 years.
Williams won Golden Globe Awards for Best Actor in “Good Morning, Vietnam, “The Fisher King” and “Mrs. Doubtfire.” He also won an Academy Award for Best Supporting Actor in “Good Will Hunting,” one of my all-time favorite movies.
Sports fans may have enjoyed the 1986 film “The Best of Times,” in which Williams played a banker who obsessed over dropping a crucial pass during a football game while he was in high school. |
Rabbit Transit (York)
The Central Pennsylvania Transportation Authority (formerly York Adams Transportation Authority), doing business as rabbittransit, is the mass transit service of York County, Pennsylvania. The agency currently operates 15 fixed routes within York County (12 in York and 3 in Hanover) and express bus routes from Gettysburg to Harrisburg and from York to Harrisburg and Towson, Maryland (connecting to the Baltimore Light RailLink of the Baltimore area's Maryland Transit Administration).
The agency, which has an annual ridership of 1.7 million, also provides paratransit services to the disabled, and a shared ride service.
rabbittransit was formerly known as York County Transit Authority. The name was changed in 2000 in order to improve the agency's image. The name is a play of "rapid transit", coincidentally echoing the same play-on-words that formed the basis of the cartoon, Rabbit Transit.
Routes
rabbittransit currently operates the following routes:
Expansion
During the late 2000s, rabbittransit has benefited from high gas prices and has seen an increase in ridership. Ridership in particular has risen on express routes, including the one operating between York and Harrisburg.
On February 2, 2009, rabbittransit introduced a new line providing six trips each weekday between York and Towson, Maryland with connection to the Baltimore Light RailLink at Timonium.
On June 6, 2011, rabbittransit (in cooperation with the Adams County Transit Authority) began operating commuter service between Gettysburg and Harrisburg with a total of four round-trips daily. The route is designated "15N".
On July 1, 2016, rabbittransit (in cooperation with Union/Snyder County Commissioners) merged with Union/Snyder Transportation Alliance (USTA)
See also
Capital Area Transit (Harrisburg)
External links
rabbittransit homepage
References
Category:Bus transportation in Pennsylvania
Category:Transportation in York County, Pennsylvania
Category:Paratransit services in the United States |
Plumbers in London
Emergency Plumbing and Heating Services in London
London plumbers with a difference.
Welcome to our website. Bates Heating and Plumbing are both CORGI and GAS SAFE registered London Plumbers; we cover all areas within the M25.
All of our plumbers in London are time served, they also have a wide knowledge and experience of both modern and old types of plumbing systems and boilers. Should you require a reliable emergency plumber in London at any time of the day or night, then our emergency plumbing service is always available, so please contact us on the above telephone number. Our Central London plumbers take pride in their work, with all plumbing jobs carried out professionally and promptly. We always treat your property with respect and leave it, in a clean and tidy condition on completion of work.
If you're tired and frustrated at waiting around all day for a plumber in London to arrive when your central heating boiler breaks down or your hot water cylinder is leaking. Our emergency plumbers in London are reliable and flexible to arrive at a time that best suits you.
Central heating installations, boiler repairs and replacements.
We are Worcester Bosch Accredited Installers of their central heating gas boilers and solar hot water heating panels in London. This means that whilst we are not tied to install their boilers, our heating engineers install service and repair Worcester Bosch boilers and can offer our customers advice on the best boiler and heating system for your needs and property. More importantly, we can offer you an extended warranty on Worcester Bosch high efficiency central heating boilers. This is an addition to the standard warranties available from other London central heating installation companies. Our heating installers work neatly and tidily and protect your property at all times. Once they have completed installing the boiler or central heating system, they will show you how to use and set the new controls that best suits you the customer. If you would like a free quotation on either a new boiler installation or full central heating system then please contact us.
Solar hot water heating London.
Bates Heating and Plumbing are also accredited Vaillant and Worcester solar hot water heating installers. We are certified by both BPEC and Logic Certification. So if when you need to replace your existing boiler for a new energy efficient, cost effective condensing boiler. Or renewing your existing inefficient hot water system you could also consider the various alternatives to the traditional heating systems. By having solar heated panels fitted to your property is an excellent way of saving money on future fuel bills. We can design, install and give you unbiased friendly advice on the installation of solar hot water heating. We have a proven track record on the installation of solar panels both with evacuated tubes and flat panels. Please get in touch if you would like a free quote on a solar hot water heating system.
Central Heating installations
Radiators
Gas Safety Certificates
Solar Heating Panels
Bathrooms
Immersion Heaters
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Cold Water Storage Tanks
Waste Disposal
Diverter Valves
Pumps
Combination Boilers
Other trades
Bates Heating and Plumbing can also supply the following quality, first class, time served tradesmen in London; electricians, bricklayers, plasterers, decorators, painters, carpenters, general builders. So should you wish to carry out a construction project, loft conversion, convert a garage, build an extension, full refurbishment or just modernise an existing property in London. We can help you plan, design and guide you through the process.
Our charges
Unlike other plumbing companies, we actually do believe in clear, upfront, transparent and competitive pricing on all of our work. All of our work / time is chargeable. We keep our overheads (like personlised number plates) to a minimum and thereby keep our customers costs reasonable. We have no reason to offer gift vouchers or discounts to entice our customers unlike others as we do not overcharge them in the first place. For more information on our charges for various types of plumbing, heating and gas work please visit our company charges page. For your convenience we accept payments by the following cheque, cash, bank transfer or credit/debit card payments, with all card payments being made by secure chip and pin.
As a professional heating and London plumbing company, Bates Heating and Plumbing London are registered with Gas Safe. The Gas Safe Register has replaced CORGI in Great Britain and the Isle of Man. The register exists to protect you, your family, and your property from dangerous gas work. By law, anyone carrying out work on gas installations and appliances in your home must be on the Gas Safe Register.
'We have used Bates Heating & Plumbing Ltd, for over five years now, for all of our plumbing and heating problems. Clasper Property Services Ltd has a large portfolio of high profile clients, who require a friendly, prompt and excellent service. We have no hesitation in recommending Bates Heating & Plumbing Ltd as a courteous and reliable business to deal with.'
Barry Nichol, Contracts Manager |
Molecular genetics of glioblastomas: defining subtypes and understanding the biology.
Despite comprehensive therapy, which includes surgery, radiotherapy, and chemotherapy, the prognosis of glioblastoma multiforme is very poor. Diagnosed individuals present an average of 12 to 18 months of life. This article provides an overview of the molecular genetics of these tumors. Despite the overwhelming amount of data available, so far little has been translated into real benefits for the patient. Because this is such a complex topic, the goal is to point out the main alterations in the biological pathways that lead to tumor formation, and how this can contribute to the development of better therapies and clinical care. |
Q:
a question about triple integral
In this question, is it right to let $x^2+z^2 = r^2$ and $x=r\cos \theta$, $z=r\sin \theta$?
A:
Let's introduce the following cylindrical coordinates
$$x=r\cos\theta,\ y=y, \ z=r\sin\theta.$$
Then, indeed $$r=\sqrt{x^2+z^2}.$$
The Jacobian of the substitution is $r$.
So after our integral transformation we have
$$\iiint_Nr^2\ dydrd\theta.$$
The following figure helps identifying $N$:
Finally, we have
$$\int_0^{2\pi}\left[\int_0^2\ r^2\left[\int_{r^2}^41\ dy\right] dr\right]\ d\theta.$$
|
A man who worked for Paul's Tree Service has been killed after he was struck by a falling tree Saturday morning.
The man, an employee of Paul's Tree Service, was working in the area. (Shane MacKichan/CBC)
WorkSafe BC said its investigators were dispatched to the scene at 7927 Huston Street on Tilbury Island in Delta at 10:15 a.m. PT.
Paul's Tree Service confirmed a worker had been killed, but declined to comment further. |
Former FBI Director James Comey used a personal email account to "conduct unclassified FBI business," the Justice Department's watchdog revealed in an explosive report on the bureau's conduct in the Hillary Clinton email investigation.
DOJ Inspector General Michael Horowitz wrote that he found Comey's use of personal email to be "inconsistent with Department policy," citing what he called "the absence of exigent circumstances and the frequency with which the use of personal email occurred."
Horowitz also revealed that FBI agent Peter Strzok used his personal email account for government business. Most notably, Horowitz wrote that Strzok forwarded an email to his personal account regarding a proposed search warrant for former Congressman Anthony Weiner's laptop computer. Horowitz wrote that the email on Strzok's personal account contained information "that appears to have been under seal at the time" in federal court.
Strzok was removed from Special Counsel Robert Mueller's Russia investigation last year after Horowitz's office discovered anti-Trump text messages between him and FBI lawyer Lisa Page.
Horowitz's revelations are an ironic footnote to the Clinton investigation, which began with the revelation that the 2016 Democratic presidential nominee had used a personal email address to conduct official correspondence while secretary of state. On July 5, 2016, Comey announced that no charges would be filed against Clinton but noted that Clinton and her aides had been "extremely careless in their handling of very sensitive, highly classified information."
Comey did not address his use of a personal email account in a New York Times op-ed responding to the Horowitz report.
"I do not agree with all of the inspector general’s conclusions, but I respect the work of his office and salute its professionalism," he wrote. Later in the piece, Comey described the Clinton investigation as "an extraordinary situation — something I thought of as a 500-year flood — offering no good choices and presenting some of the hardest decisions I ever had to make ... But even in hindsight I think we chose the course most consistent with institutional values." |
[unreadable] Cystic fibrosis (CF) is the most common severe autosomal recessive disease in Caucasian individuals. CF is characterized by an imbalance in the movement of salt and water across the airway surface, such that the overlying mucus layer becomes dehydrated, collapses onto the airway wall, and fails to be cleared from the airways. This impaired mucus clearance leads to chronic infection and airways obstruction, and ultimately causes respiratory failure leading to premature death or lung transplantation. Sodium absorption through the epithelial sodium channel (ENaC), which establishes an osmotic driving force for the absorption of airway surface liquid (ASL), is abnormally high in CF patients for unknown reasons. Furthermore, when the activity of ENaC is inhibited in CF, the ASL becomes hydrated and mucus clearance improves. Our preliminary work suggests that imbalances between proteases, which activate the channel, and endogenous protease inhibitors on the luminal airway surface causes sodium hyperabsorption in CF airways. The goal of this K08 application is to provide the PI with essential skills to develop into a successful academic physician and achieve independent scientific investigator status with a focus on airway physiology as it relates to CF. The PI will focus upon the regulation of airway surface liquid volume by ENaC in normal and CF airway epithelium. The primary scientific aims of this proposal are to (i) define the role of the protease/protease inhibitor balance in the physiological regulation of ENaC and ASL depth, (ii) determine which channel activating proteases and protease inhibitors are involved in the regulation of ENaC in the airway, and (iii) define the mechanism by which proteolytic processing of ENaC is altered in CF. To achieve his goal and complete these aims the PI will combine focused graduate course work with state-of-the-art laboratory methods to delineate the electrophysiology and biochemistry of ENaC in primary human airway epithelial cells and relevant heterologous expression systems. Understanding the nature of proteolytic regulation of ENaC activity in normal and diseased airways will ultimately direct the development of novel therapies to mitigate sodium hyperabsorption and thereby restore normal ASL volume and mucus clearance in CF airways. [unreadable] (End of Abstract) [unreadable] [unreadable] [unreadable] |
//
// AKBitCrusherDSP.hpp
// AudioKit
//
// Created by Aurelius Prochazka, revision history on Github.
// Copyright © 2018 AudioKit. All rights reserved.
//
#pragma once
#import <AVFoundation/AVFoundation.h>
typedef NS_ENUM(AUParameterAddress, AKBitCrusherParameter) {
AKBitCrusherParameterBitDepth,
AKBitCrusherParameterSampleRate,
AKBitCrusherParameterRampDuration
};
#ifndef __cplusplus
AKDSPRef createBitCrusherDSP(int channelCount, double sampleRate);
#else
#import "AKSoundpipeDSPBase.hpp"
class AKBitCrusherDSP : public AKSoundpipeDSPBase {
private:
struct InternalData;
std::unique_ptr<InternalData> data;
public:
AKBitCrusherDSP();
float bitDepthLowerBound = 1;
float bitDepthUpperBound = 24;
float sampleRateLowerBound = 0.0;
float sampleRateUpperBound = 20000.0;
float defaultBitDepth = 8;
float defaultSampleRate = 10000;
int defaultRampDurationSamples = 10000;
// Uses the ParameterAddress as a key
void setParameter(AUParameterAddress address, float value, bool immediate) override;
// Uses the ParameterAddress as a key
float getParameter(AUParameterAddress address) override;
void init(int channelCount, double sampleRate) override;
void deinit() override;
void process(AUAudioFrameCount frameCount, AUAudioFrameCount bufferOffset) override;
};
#endif
|
NYPD stop-and-frisk whistleblowers facing retribution
Cops who testified against the New York City Police Department’s stop-and-frisk policy have faced retribution from higher-ups and officers who subscribe to the idea that the controversial tactic, deemed unconstitutional by major courts, is fair and legal.
NYPD officer Pedro Serrano told the Associated Press he’s faced
harassment at work after testifying that stop-and-frisk, which was
enacted in 2002, targets minorities and requires patrol officers to
meet monthly quotas.
Serrano said that, along with finding a sticker of a rat pasted
to his locker, he says he's been micromanaged - including
transferral to a different precinct to work an overnight shift. He
also claimed that he was refused overtime hours amid an otherwise
erratic schedule.
“A lot of people told me not to come forward because of what
would happen – they said the department would come after me,”
Serrano said. “But I’ve been thinking about it since 2007. I
felt I couldn’t keep quiet.”
Serrano, along with fellow officers Adrian Schoolcraft and Adhyl
Polcano, secretly recorded hours of patrol briefings and meetings
with superior officers. The audio was played during the current
federal trial meant to determine if black and Hispanic men are
targeted by NYPD cops seeking to boost their numbers.
Polcano testified that he was told he needed to have 20
summonses, five street stops and one arrest each month.
“I was extremely bothered by what I was seeing out
there,” he said on the stand. “The racial profiling, the
arresting people for no reason, being called to scenes that I did
not observe a violation and being forced to write a summons that I
didn’t observe.”
Polcano was suspended from duty and charged with filing false
arrest paperwork after he detailed a list of grievances to the
police department’s internal affairs. He now works in a video
review department. Schoolcraft, who remains suspended, did not
testify at the trial because he has filed his own federal suit
accusing superior officers of forcefully taking him to a
psychiatric hospital in 2009.
Other officers who testified painted Serrano’s complaints as an
unfortunate but necessary part of the job. Joseph Esposito, the
former chief of the department, testified that most officers
“leave their house every day to go to work to protect the city.
They have the best intentions all the time, and they do it. There
is a small percentage…we’re talking about in any profession, there
is a group that will try to do the least amount and get paid the
most.”
The alleged harassment would fit in the narrative of the NYPD.
In the early 1970s plainclothes officer Frank Serpico accused the
department of widespread corruption only to be shot in the face
during a later investigation. Labeled a traitor by the police but a
hero by others, Serpico was portrayed by Al Pacino in a popular
eponymous movie chronicling his story two years later.
During an interview with the Associated Press Serpico said
recent events prove NYPD groupthink hasn’t evolved past a “kill
the messenger” mentality.
“I’ve become their grandfather,” he said. “They don’t
want nothing. They just want somebody who knows what they’re going
through. I give them moral support.”
The trial has been underway for more than a month, and recently
included testimony from a parade of officers trying to discredit
Polcano and Serrano as malcontents who often caused trouble. NYPD
policy dictates that officers are required to report corruption
without fear of retribution.
“It hasn’t been a picnic,” Serrano said. “They have
their methods of dealing with someone like me.” |
Q:
Rails 3 Conditional Validation (credit cards): Syntax Error
Seems odd, seems right?
validates_presence_of [:visa, :mc, :discover, :amex], :if => :credit_card => true
Any input is appreciated, getting a syntax error in the browser. Thanks.
A:
Try this
validates :visa, :mc, :discover, :amex, :presence => true, :if => :credit_card?
if credit card is a boolean field.
else define a method
def credit_card?
credit_card.present?
end
|
Caesarean section increases the risk of hospital care in childhood for asthma and gastroenteritis.
To investigate if caesarean section (CS) increases the risk for childhood asthma and gastroenteritis with reference made to children born with vaginal delivery (VD). Retrospective study of data from linked Swedish medical service registers--Medical Birth Registry (MBR) and Hospital Discharge Registry (HDR). Data were obtained from women without any background/perinatal morbidity noted, and from children without any neonatal complications. Children that had reached at least 1 year of age and were found in the HDR were considered as cases, whereas children not found in the HDR or hospitalized for other causes than asthma or gastroenteritis were defined as controls. Odds ratios (OR) stratified for year of birth, maternal age, parity and smoking in early pregnancy were calculated. Investigations were made comparing the risk for in hospital treatment for asthma or gastroenteritis in CS children and in VD siblings of CS children. The overall inpatient morbidity in CS and VD children were also investigated. The OR for asthma in CS children was 1.31 [95% confidence interval (CI) 1.23-1.40]. The same OR, 1.31, was found for gastroenteritis (95% CI 1.24-1.38). The OR for CS children having experienced both asthma and gastroenteritis was further increased (1.74, 95% CI 1.36-2.23). The risk for asthma in VD siblings of CS children was not significantly increased, whereas VD siblings experienced a slightly increased risk for gastroenteritis. CS children had an increased overall in hospital morbidity when compared to VD children. There is a significant increase of the risk for developing symptoms of asthma and/or gastroenteritis that motivates admission for hospital care in CS children older than 1 year. It is speculated that a disturbed intestinal colonization pattern in CS children may be a common pathogenic factor. |
Support the credit position, but would add that should NOT be open for East
Power.
From: Tana Jones @ ECT 03/16/2001 11:52 AM
To: Marcus Nettelton/NA/Enron@ENRON
cc:
Subject: RE: Bonneville Power Administration
---------------------- Forwarded by Tana Jones/HOU/ECT on 03/16/2001 11:49 AM
---------------------------
From: Tom Moran/ENRON@enronXgate on 03/16/2001 08:39 AM
To: Tana Jones/HOU/ECT@ECT, Walter Guidroz/ENRON@enronXgate
cc:
Subject: RE: Bonneville Power Administration
The only restriction is coming from our cautious, power credit team wanting
to only sell to BPA at this time.
-----Original Message-----
From: Jones, Tana
Sent: Thursday, March 15, 2001 6:43 PM
To: Guidroz, Walter; Moran, Tom
Subject: Bonneville Power Administration
Taking a look at BPA from the 3/8/01 list, I noticed that we've got them
opened up for west coast power only on the offer and not the bid. I have no
notes that they are restricted in that manner. What's the scoop? Marcus, do
you see any reason they should be restricted to the offer side? |
var mathUtils = require('./mathUtils')
/**
* 3D point class for panner, listener, etc.
* The original idea is from chromium's Web Audio API implementation.
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/geometry/FloatPoint3D.h
*/
class FloatPoint3D {
/**
* @param {number} [x=0]
* @param {number} [y=0]
* @param {number} [z=0]
*/
constructor(x, y, z) {
this.x = x || 0
this.y = y || 0
this.z = z || 0
}
/**
* @return {boolean}
*/
isZero() {
return !this.x && !this.y && !this.z
}
normalize() {
const tempNorm = this.norm()
if (tempNorm) {
this.x /= tempNorm
this.y /= tempNorm
this.z /= tempNorm
}
}
/**
* @param {FloatPoint3D} a
*/
dot(a) {
return this.x * a.x + this.y * a.y + this.z * a.z
}
/**
* Compute the cross product for given point, and return it as a new FloatPoint3D.
* @param {FloatPoint3D} point
* @return {FloatPoint3D}
*/
cross(point) {
const x = this.y * point.z - this.z * point.y
const y = this.z * point.x - this.x * point.z
const z = this.x * point.y - this.y * point.x
return new FloatPoint3D(x, y, z)
}
/**
* @return {number}
*/
normSquared() { return this.dot(this) }
/**
* @return {number}
*/
norm() { return Math.sqrt(this.normSquared()) }
/**
* @param {FloatPoint3D} a
* @return {number}
*/
distanceTo(a) {
return this.sub(a).norm()
}
/**
* @param {FloatPoint3D} a
*/
add(a) {
return new FloatPoint3D(
this.x + a.x,
this.y + a.y,
this.z + a.z
)
}
/**
* @param {FloatPoint3D} a
*/
sub(a) {
return new FloatPoint3D(
this.x - a.x,
this.y - a.y,
this.z - a.z
)
}
/**
* @param {FloatPoint3D} a
* @return {FloatPoint3D} - this * a
*/
mul(k) {
return new FloatPoint3D(k * this.x, k * this.y, k * this.z)
}
/**
* @param {FloatPoint3D} y
* @return {number} - angle as radius.
*/
angleBetween(y) {
const xNorm = this.norm()
const yNorm = y.norm()
if (xNorm && yNorm) {
const cosAngle = this.dot(y) / (xNorm * yNorm)
return Math.acos(mathUtils.clampTo(cosAngle, -1.0, 1.0))
}
return 0
}
/**
* @return {Array<number>}
*/
toArray() {
return [this.x, this.y, this.z]
}
}
module.exports = FloatPoint3D
|
Image copyright Getty Images Image caption While many people bought Trump wigs for Halloween, others did buy them to wear at his rallies
While Donald Trump's US presidential election victory was a hair-raising shock for many people, owners of fancy dress shops had been predicting it for weeks.
When most pollsters and political pundits said Hillary Clinton would win last week, they were in fact ignoring an unusual but perhaps key statistic in the 2016 race for the White House - sales of wigs modelled on the hairstyles of the two candidates.
And in the battle of the wigs Donald Trump won, not by a hair's breadth but by a country mile.
"We sold roughly 150 Trump-style wigs... versus about 50 or so Hillary-style wigs," says Coutland Hickey, owner of the Chicago Costume Company.
Timothy Connor, owner of British wig website The Hairdrobe - which was selling 400 Trump wigs around the world per day - says the disparity in sales at his business was even more pronounced: "Trump wiped the floor against Hillary."
Image copyright Chicago Costume Company Image caption Sales of Trump wigs dwarfed those of Clinton
Meanwhile, London-based Angels Fancy Dress sold 500 Trump wigs to 300 Hillary ones. "This is a convincing victory," says manager Emma Angel.
But why were Trump wigs so much more popular over the past few months? And did his rather unique bouffant and back-combed hairstyle have any effect on the election result?
'Unique visual attribute'
Ms Angel, who also runs the Fancydress.com website, says she had long recognised that selling £9.99 Trump wigs would be a good business opportunity, but that "demand exceeded even our expectations".
"Politics has increasingly become a spectator sport, and over the past decade politicians have become a theme for costume parties," she says.
"And love him or loathe him, Trump has a truly unique visual attribute in terms of his hair."
Image copyright Getty Images Image caption Donald Trump definitely has a unique hairstyle
She adds that the fact the US presidential election took place just after Halloween also boosted sales of Trump wigs, and people - both US expats living in London and British customers - bought them as part of their costume. However, she cautions that not every purchaser was a fan of the president-elect.
"Some consumers were buying Trump items as they associated him with villainy, others as he was perceived as a hero," she says. "But it certainly reflected Trump's position as a pop cultural phenomenon who was very much front-of-mind."
In contrast to Ms Angel, The Hairdrobe's Timothy Connor admits that he initially thought "it was a bit of a gamble" to create a Trump wig, saying "we weren't sure how well they would do". Then sales skyrocketed.
Image copyright Getty Images Image caption Did Donald Trump's hairstyle play any part in him becoming the next US president?
Mr Hickey's opinion is that Trump wigs were always going to outsell those of Clinton for fancy dress purposes because his hairstyle is "much more costumey" and recognisable than Clinton's.
"People yearn for others to 'get' their costume," he says. "And to dress as Trump, with the crazy hair and orange skin is more recognisable for everyone. Which is why I think it was more popular.
"Additionally, being such a polarising figure he is more popular to dress as in order to poke fun at."
Look like a celebrity
With wig and hairpiece revenues in the US alone worth an estimated $224m (£180m) in 2015, sales of Trump and Clinton wigs are obviously just two strands in a forest of real and artificial hair.
Yet the fact people have bought them needs to be seen in the wider context of how social media has given overall wig sales a boost.
Image copyright Chicago Costume Company Image caption Sales of Hillary Clinton wigs trailed far behind those of Donald Trump
"Social media - especially platforms like Instagram - have really introduced a new dimension to the business and boosted sales," says Mr Connor.
"Everything is much more visual now, people want to look good or quirky on their social media profiles. If they go to a fancy dress party they want nice photos of themselves.
"And they see celebrities on Instagram or reality TV, and wigs allow them to look like celebrities."
But if Donald Trump did win the battle of the wig sales, did his famous hairstyle actually contribute to his election victory or was it a handicap he had to overcome?
London-based hairdresser Joshua Coombes says that as perverse as it sounds, the haircut probably did help.
"It is an appalling haircut, but together with the orange skin, it is a huge part of Trump's identity," says Mr Coombes, who made headlines earlier this year for his work cutting homeless people's hair for free.
"And the hair is a part of Trump's marketing, his branding. Like it or not, it is part of his identity and success.
"He must spend a long time blow-drying it though." |
349 S.W.3d 717 (2011)
Clayton NEWELL, Appellant,
v.
Christina N. NEWELL, Appellee.
No. 02-10-00301-CV.
Court of Appeals of Texas, Fort Worth.
August 18, 2011.
*718 Alison Porterfiled, Schneider Law Firm, P.C., Fort Worth, for Appellant.
Julie Krenek, Raggio and Raggio, P.L.L.C., Dallas, for Appellee.
PANEL: LIVINGSTON, C.J.; WALKER, and McCOY, JJ.
OPINION
SUE WALKER, Justice.
I. INTRODUCTION
This is an appeal from a divorce decree that orders Appellant Clayton Newell to pass random drug and alcohol testing in order to be entitled to unrestricted possession of his daughter. In two issues, Clayton argues that the trial court abused its discretion by ordering the random alcohol testing and that the restriction exceeds that required to protect the best interest of his daughter. We will modify the trial court's judgment to delete the requirement that Clayton submit to random alcohol testing and affirm the trial court's judgment, including the random drug tests, as modified.
II. FACTUAL AND PROCEDURAL BACKGROUND
Clayton married Appellee Christina N. Newell in May 2003. During the marriage, *719 Clayton and Christina had one child, N.A.N. (Natalie).[1]
Clayton used drugs as a teenager, and he began abusing drugs in the fall of 2007 when his younger brother died. Clayton went to outpatient rehabilitation in May 2009, and he and Christina separated in June 2009. The next month, Clayton filed a petition for divorce. He asked that he and Christina be appointed joint managing conservators of Natalie. A few days later, Christina filed a counterpetition in which she requested sole managing conservatorship of Natalie and asked the trial court to enter all orders that the court found to be in Natalie's best interests. The trial court entered temporary orders, which included making Clayton's possession of Natalie contingent upon him passing drug tests that Christina was required to pay for.
In July 2010, the parties agreed to have permanent joint managing conservatorship of Natalie, with Christina serving as her primary caregiver and Clayton having scheduled possession rights. Through a written agreement,[2] the parties decided to submit to the trial court "the one remaining issue regarding the divorce decree; specifically whether drug testing ends at 5 years or if [Clayton] is still unemployed if it will continue once a year until he is gainfully employed."
At trial, Clayton presented evidence of drug tests that he passed in July 2009, August 2009, September 2009, December 2009, and June 2010; a July 2009 urine test was negative for all drugs tested, but the hair follicle test of the same day was positive for opiates and cocaine. Clayton testified that his sobriety date was June 2009 and that he had stopped using drugs more than a year before the July 2010 trial began. He admitted that he has stopped attending Narcotics Anonymous meetings because he does not own a vehicle.
Regarding his alcohol use, Clayton testified that he drinks alcohol (including during communion at his church), that he has abused alcohol in the past, but that he has never been addicted to alcohol. He said that he was not, at the time of trial, drinking in excess to the point of intoxication. Clayton testified that it was fair for the trial court to subject him to random drug tests and to enjoin him and Christina from drinking alcohol during or within twelve hours before either of them possessed Natalie. However, he said that he did not think it was fair to be subjected to alcohol testing concurrently with the drug tests because "it is legal to consume alcohol in the privacy in [his] home, in a restaurant[,] or in any other social context. It's too intrusive." Clayton said that he would never drink around Natalie.
Christina testified that Clayton had "been high" around Natalie in the past and expressed concern that he would return to using drugs. She explained that he had used prescription painkillers "to excess" and had smoked marijuana on a few occasions while he was on parole in 2007. In response to a question from the trial court about why she wanted Clayton to also be tested for alcohol consumption, Christina said, "Because I know from past experience living with him that he does have an issue with alcohol abuse. My daughter numerous times comes home from her weekends with him and state[s] that he drinks."
*720 The final divorce decree orders Clayton to submit to random alcohol tests (concurrently with the drug tests) up to three times per year for five years; the alcohol tests will determine whether he has consumed alcohol within the eighty hours preceding the tests and must occur within twelve hours of his possession of Natalie. Christina must pay for the tests as long as Clayton continues to test negative. The tests must be completed on the same day that a testing facility notifies Clayton that he is required to take them. If Clayton fails to appear for a test or tests positive for using drugs or alcohol, Clayton's periods of possession of Natalie are modified and restricted.[3]
Clayton filed a motion for new trial, contending that the evidence is legally and factually insufficient to support the trial court's decision to require him to submit to alcohol testing; he does not contest the drug testing. At a hearing on Clayton's motion, the trial court offered to modify the random alcohol testing provision if Clayton agreed to wear a SCRAM device while he has possession of Natalie, provided that he pay all costs of the device. Clayton declined, the court denied Clayton's motion, and he brought this appeal.
III. RANDOM ALCOHOL TESTING
In two issues, Clayton contends that the trial court abused its discretion by ordering him to be tested for alcohol consumption because the order is not based on factually sufficient evidence and because the restriction exceeds that required to protect Natalie's best interests.[4]
A. Standard of review
We review the trial court's decisions on custody, control, possession, and visitation matters for an abuse of discretion. In re M.M.M., 307 S.W.3d 846, 849 (Tex.App.-Fort Worth 2010, no pet.); see Gillespie v. Gillespie, 644 S.W.2d 449, 451 (Tex.1982); In re W.M., 172 S.W.3d 718, 724 (Tex.App.-Fort Worth 2005, no pet.). To determine whether a trial court abused its discretion, we must decide whether the court acted without reference to any guiding rules or principles; in other words, we must decide whether the act was arbitrary or unreasonable. M.M.M., 307 S.W.3d at 849; see Low v. Henry, 221 S.W.3d 609, 614 (Tex.2007); W.M., 172 S.W.3d at 725.
In our review of a child custody ruling under the abuse of discretion standard, legal and factual sufficiency are not independent grounds of error but are relevant factors in deciding whether the trial court abused its discretion. In re T.D.C., 91 S.W.3d 865, 872 (Tex.App.-Fort Worth 2002, pet. denied) (op. on reh'g); see W.M., 172 S.W.3d at 725. In determining whether there has been an abuse of discretion because the evidence is legally or factually insufficient to support the trial court's decision, we consider whether the court had *721 sufficient information upon which to exercise its discretion and whether it erred in its application of that discretion. M.M.M., 307 S.W.3d at 849; W.M., 172 S.W.3d at 725; T.D.C., 91 S.W.3d at 872. "The traditional sufficiency review comes into play with regard to the first question. With regard to the second question, we determine, based on the elicited evidence, whether the trial court made a reasonable decision." W.M., 172 S.W.3d at 725 (footnote omitted).
B. Law on Restrictions on a Parent's Right of Possession
"The best interest of the child shall always be the primary consideration of the court in determining the issues of conservatorship and possession of and access to the child." Tex. Fam.Code Ann. § 153.002 (West 2008); Lenz v. Lenz, 79 S.W.3d 10, 14 (Tex.2002); M.M.M., 307 S.W.3d at 850. There is a rebuttable presumption that the standard possession order provides reasonable minimum possession for a parent named as a joint managing conservator and is in the child's best interest. Tex. Fam.Code Ann. § 153.252 (West 2008).
If special circumstances make the standard possession order unworkable or inappropriate, however, "[t]he court shall render an order that grants periods of possession of the child as similar as possible to those provided by the standard possession order." Id. § 153.253 (West 2008); see In re J.E.P., 49 S.W.3d 380, 385 & n. 15 (Tex.App.-Fort Worth 2000, no pet.). In deviating from the standard possession order, the trial court may consider the age, developmental status, circumstances, needs, and best interest of the child; the circumstances of the managing conservators; and any other relevant factor. Tex. Fam.Code Ann. § 153.256 (West 2008); J.E.P., 49 S.W.3d at 387. An order that imposes restrictions or limitations on a parent's right to possession of or access to a child may not exceed terms that are required to protect the best interests of the child. Tex. Fam.Code Ann. § 153.193 (West 2008); see M.M.M., 307 S.W.3d at 854; see also In re J.S.P., 278 S.W.3d 414, 419 (Tex.App.-San Antonio 2008, no pet.) ("[A] trial court's ultimate goal is to minimize restrictions placed on a parent's right of possession of or access to their child.").
C. Random Alcohol Testing Order Exceeded Terms Required to Protect Natalie's Best Interest
The facts regarding Clayton's past alcohol abuse and present alcohol use are sparse and limited, while the alcohol testing requirement in the trial court's order is quite dramaticeffectively requiring Clayton to abstain from any alcohol consumption for eighty hours (or possibly ninety-two hours[5]) preceding any period of possession of Natalie, or otherwise risk modified, supervised visitation of his daughter. We conclude that, based on the limited evidence in the record concerning Clayton's alcohol use, the trial court's order unreasonably exceeded the terms required to protect Natalie's best interest and constituted an abuse of discretion. See Tex. Fam.Code Ann. § 153.193; M.M.M., 307 S.W.3d at 849.
Although the record demonstrates that Clayton had a drug addiction, no evidence exists that Clayton has ever had an alcohol addiction, that his drinking ever endangered Natalie in any way, or that all drug addicts are also alcohol addicts. No medical records or prior alcohol-related incidents *722 or convictions relating to any alcohol use by Clayton were offered into evidence at trial. Christina's only testimony regarding Clayton's alcohol use and her reason for requesting alcohol testing was that she knew from living with him in the past "that he does have an issue with alcohol abuse" and that Natalie has told her in the past, after spending the weekend with Clayton, "that he drinks." No evidence exists that Clayton has ever been drunk around his daughter, that he was drinking to the point of intoxication at the time of trial, that his current or past alcohol use is or ever was detrimental to Natalie or Christina, that he ever drove after drinking, that his personality changed when he drank, or that consuming alcohol within ninety-two hours prior to having possession of Natalie would in any way negatively impact her best interests. Cf., e.g., In re A.L.E., 279 S.W.3d 424, 429-30 (Tex. App.-Houston [14th Dist.] 2009, no pet.) (upholding modification of custody order when "record [was] replete with evidence that [mother's] substance-abuse problems have significantly, and negatively, affected A.L.E. since she came to reside with her mother"); Ohendalski v. Ohendalski, 203 S.W.3d 910, 913, 915-16 (Tex.App.-Beaumont 2006, no pet.) (affirming order that prohibited father from driving with children in car when father had history of chronic alcohol abuse, drank during supervised visitations, and "terrorized" children by driving under the influence); Hopkins v. Hopkins, 853 S.W.2d 134, 138 (Tex. App.-Corpus Christi 1993, no writ) (upholding restrictions on father's access to children based on evidence that he had been convicted of delivery of controlled substances, used drugs in front of the children, and physically abused mother and oldest child on multiple occasions); see also In re L.M.M., No. 03-04-00452-CV, 2005 WL 2094758, at *5, 8 (Tex.App.-Austin Aug. 31, 2005, no pet.) (mem. op.) (finding allegations that father drank and drove not corroborated by testimony when father admitted to drinking in the evenings with children present but not to point of intoxication and said he never drives intoxicated, and when other witnesses confirmed that he does not drink and drive). Furthermore, the evidence in the record shows that Clayton had been drug-free the entire year preceding trial[6] and that he agreed not to drink during or within twelve hours prior to any possession of Natalie.
Clearly, the trial court has discretion to order alcohol testing on appropriate facts. See Tex. Fam.Code Ann. § 153.253, .256; see also A.L.E., 279 S.W.3d at 433 (upholding order requiring drug and alcohol testing). But, in this case, considering the limited facts regarding Clayton's alcohol use in the past and at the time of trial; considering that in the year prior to trial, he tested negative for drug use multiple times; and considering the drastic restriction placed on Clayton's alcohol use and the severe consequences of a positive alcohol testwhich could be attributable to alcohol Clayton drank while Natalie was not in his possessionwe hold that the trial court's order requiring three random, eighty-hour alcohol tests exceeded the restrictions required to protect Natalie's best *723 interest.[7]See Tex. Fam.Code Ann. § 153.193; see also Pierre, 50 S.W.3d at 559 (holding that trial court abused its discretion by requiring father to submit to drug and alcohol testing at his expense "in the absence of any evidence of drug abuse"). Consequently, we hold that the trial court abused its discretion by entering the order that it entered, and we sustain Clayton's second issue.[8]See M.M.M., 307 S.W.3d at 849.
IV. CONCLUSION
Having sustained Clayton's second issue, we modify the trial court's judgment to delete the requirement that Clayton submit to random alcohol testing and affirm the trial court's judgment as modified. See Tex.R.App. P. 43.2(b).
LIVINGSTON, C.J. filed a dissenting opinion.
McCOY, J. filed a concurring opinion.
BOB McCOY, Justice, concurring.
I concur that the trial court abused its discretion by entering the judgment it entered concerning testing for alcohol use but for a different reason than enunciated by my fellow justice. I believe that the trial court has the right, and in fact, the obligation to order alcohol testing depending on the circumstances. I further believe that there is sufficient evidence in this case to warrant testing pursuant to the court's judgment except as to the timing of the testing. To test within twelve hours of possession of Natalie seems to imply that it is to be within twelve hours after the beginning of the possession of Natalie, but as worded, could also theoretically be from twelve hours before the beginning of the possession of Natalie until twelve hours after the end of possession of Natalie. It is only testing at the later time that accomplishes the obvious purpose of the requirement, that is, to ensure that Clayton not drink alcohol while in possession of his daughter. Any testing while in *724 possession, or prior to possession of Natalie, would allow Clayton to drink alcohol after the test but while in possession of his daughter.
For the foregoing reason, I concur in the outcome reached by my fellow justice.
TERRIE LIVINGSTON, Chief Justice, dissenting.
While the majority's opinion correctly explains the abuse of discretion standard that we employ when reviewing a trial court's decision in a conservatorship appeal, the majority errs in applying that standard because the trial court's decision to require Clayton to take three random alcohol tests per year within twelve hours of possessing Natalie is neither arbitrary nor unreasonable. See In re W.M., 172 S.W.3d 718, 724 (Tex.App.-Fort Worth 2005, no pet.) (explaining that the "trial court has wide latitude in determining the best interests of a minor child"). We must be cognizant that the trial court is in a better position to decide issues within custody cases because "it faced the parties and their witnesses, observed their demeanor, and had the opportunity to evaluate the claims made by each parent." In re M.M.M., 307 S.W.3d 846, 849 (Tex. App.-Fort Worth 2010, no pet.) (quoting In re J.R.D., 169 S.W.3d 740, 743 (Tex.App.-Austin 2005, pet. denied)). An abuse of discretion does not occur as long as some evidence of substantive and probative character exists to support the decision. W.M., 172 S.W.3d at 725.
The best interests of the child must be the primary consideration of the trial court when determining issues of conservatorship and possession of and access to a child. Tex. Fam.Code Ann. § 153.002 (Vernon 2008); M.M.M., 307 S.W.3d at 850.[1] The trial court's order requiring Clayton to submit to alcohol testing does not deny his possession of Natalie; it imposes restrictions on his right to possess her. The trial court asked Christina about the basis for her desire to require alcohol testing. She said, "Because I know from past experience living with him that he does have an issue with alcohol abuse. My daughter numerous times comes home from her weekends with him and state[s] that he drinks." [Emphasis added.] The trial court could have determined that Christina's present-tense explanation of Clayton's alcohol consumption around Natalie weakened his credibility on the rest of his testimony concerning the nature of his alcohol consumption because he had previously testified that he would never drink around her.[2] Although Clayton denied ever having an addiction to alcohol, he admitted that he has abused alcohol in the past. He further admitted that he still drinks alcohol. He conceded that he thought that it was fair for the court to enjoin both parents from drinking alcohol while in possession of Natalie or within twelve hours of that possession.
Clayton also has a history of drug addiction, including the use of heroin, cocaine, and marijuana. He admitted that he has stopped attending Narcotics Anonymous meetings because he does not own a vehicle. The trial court could have reasonably found that Clayton's problem with drug abuse, including prior relapses and the use *725 of drugs even after attending rehabilitation, justified also testing him for alcohol consumption, particularly because he admitted that he had abused alcohol in the past. Cf. In re Pierre, 50 S.W.3d 554, 559 (Tex.App.-El Paso 2001, orig. proceeding) ("[I]n the absence of any evidence of drug abuse . . . the trial court abused its discretion by requiring Relator to submit to drug and alcohol testing and ordering him to pay for the same."). I would hold that the trial court had sufficient information upon which to exercise its discretion and did not err in its application of that discretion by weighing evidence that produced conflicting inferences about Clayton's extent of alcohol use (including use around Natalie) and the need for alcohol testing. See M.M.M., 307 S.W.3d at 849; W.M., 172 S.W.3d at 725.
Clayton also argues that because the alcohol testing ordered by the trial court requires screening for the preceding eighty-hour period even though he will not always have possession of Natalie during the entire eighty hours, he could test positive for alcohol yet not be in violation of the agreed injunction. Therefore, Clayton contends, the trial court cannot impose such a restriction. I find this argument unpersuasive. The trial court asked the parties whether there was a test available that would cover a lesser period of time. Christina's counsel stated that she did not know of any such test (and Clayton did not offer to take such a test if one exists). Thus, the trial court decided to leave the eighty-hour test in place. The court could have reasonably determined that Natalie's best interests required Clayton to refrain from consuming alcohol during or immediately before his possession of her, and Clayton conceded that it was fair that he not drink within twelve hours of possessing her. He did not, however, propose a means other than the eighty-hour test of ensuring that result while still allowing him to drink at times before his immediate possession of her. During a hearing on Clayton's motion for new trial, the trial court offered such an alternativeto wear a device (at his expense) that would detect his alcohol consumption only while he possessed Nataliebut he did not choose to do so.
For these reasons, I would hold that the trial court did not abuse its discretion by including the provisions regarding alcohol testing in the judgment, and I would therefore affirm the judgment.
Finally, even if I agreed with the majority's conclusion that the trial court abused its discretion, I would still dissent to the majority's disposition of the appeal. The majority essentially holds that the trial court abused its discretion because the facts of this case are inappropriate and insufficient to show that Clayton's random alcohol tests are in Natalie's best interests. See Majority Op. at 722-23. In such a situation, unless the majority expressly holds that there was no evidence to support the trial court's decision, it should remand, based on factual insufficiency, rather than deleting the alcohol testing requirement. See Glover v. Tex. Gen. Indem. Co., 619 S.W.2d 400, 401-02 (Tex. 1981) (holding that if a court of appeals sustains an issue or point because the evidence is factually insufficient, it must reverse the judgment of the trial court and remand for new trial); In re T.D.C., 91 S.W.3d 865, 877 (Tex.App.-Fort Worth 2002, pet. denied) (op. on reh'g) (remanding a custody case based on a determination that the trial court abused its discretion because its decision was based on factually insufficient evidence); Enriquez v. Krueck, 887 S.W.2d 497, 503 (Tex.App.-San Antonio 1994, no writ) (same); see also In re J.O.A., 283 S.W.3d 336, 347 (Tex.2009) ("[A] remand is . . . the appropriate judgment when evidence is found to *726 have been factually insufficient[.]"); Wilson v. Wilson, 132 S.W.3d 533, 534, 539 (Tex.App.-Houston [1st Dist.] 2004, pet. denied) (remanding a case regarding the division of a community estate because of an abuse of discretion based on factual insufficiency).[3]
For all of these reasons, I dissent to the majority's opinion and judgment.
NOTES
[1] To protect Natalie's identity, we will use an alias. See Tex. Fam.Code Ann. § 109.002(d) (West 2008). The divorce decree states that Christina gave birth to Natalie on November 22, 2005.
[2] See Tex.R. Civ. P. 11.
[3] The divorce decree states that if Clayton provides negative drug and alcohol tests and lives within 100 miles of Natalie, he may possess Natalie, among other agreed times, during some weekends, for two hours each Thursday during the school term, during spring break in even-numbered years, for thirty days during the summer, and during some holidays. If he tests positive, he may exercise only ten hours of supervised possession every other Saturday. Once he tests positive, he must provide three negative tests within a ninety-day period to again be entitled to unrestricted possession rights.
[4] Christina argues on appeal that because the parties entered into a valid, signed Rule 11 agreement, the only issue before the trial court was whether Clayton's random drug testing should continue beyond a five-year period. The alcohol testing issue, however, was tried by consent at trial. See Tex.R. Civ. P. 67; Roark v. Stallworth Oil & Gas, Inc., 813 S.W.2d 492, 495 (Tex.1991).
[5] We interpret the requirement that the random alcohol testing occur "within twelve (12) hours of Clayton Newell's possession of the child" to mean that Christina could order the testing to occur up to twelve hours before or after Clayton's possession of Natalie.
[6] The record suggests that the trial court included the alcohol testing requirement, at least in part, based on Clayton's prior drug abuse. At the end of trial, the trial court explained,
I think given the drugs that you chose to use, heroin and cocaine, which are pretty hard drugs and fairly addictive, andand it takes a while before youand even the experts agree someone has kicked an addiction. I'm going to go ahead and sign the decree with the provisions in here as they are.
[7] The dissent argues that we must remand this case for a new trial, rather than delete the alcohol testing requirement, unless we hold that no evidence supports the trial court's decision. Dissenting Op. at 725-26. However, as we mentioned above, in family law cases, legal and factual insufficiency are not independent reversible grounds of error but are relevant factors in assessing whether the trial court abused its discretion. T.D.C., 91 S.W.3d at 872; see W.M., 172 S.W.3d at 725. In other words, the applicable abuse of discretion standard of review overlaps with the traditional sufficiency standard of review. Boyd v. Boyd, 131 S.W.3d 605, 611 (Tex.App.-Fort Worth 2004, no pet.). Here, having considered the sufficiency of the evidence in assessing whether the trial court abused its discretion as alleged in Clayton's second issue, and having held that the trial court did in fact abuse its discretion by ordering the alcohol testing that it ordered because it exceeded the restrictions required to protect Natalie's best interest, the appropriate remedy is to delete the alcohol testing requirement from the decree and affirm as modified. See, e.g., In re K.N.C., 276 S.W.3d 624, 628 (Tex.App.-Dallas 2008, no pet.) (modifying decree to name two specific individuals, agreed to by the parties, as alternative visitation supervisors, rather than allowing mother to effectively veto father's visitation if she did not agree upon supervisor); In re C.A.M.M., 243 S.W.3d 211, 223 (Tex.App.-Houston [14th Dist.] 2007, pet. denied) (reforming trial court's order to remove requirement of supervised visitation); In re Pierre, 50 S.W.3d 554, 559 (Tex.App.-El Paso 2001, no pet.) (reforming trial court's order to omit alcohol and drug testing requirement).
Our holding in no way limits Christina's ability to seek modification of the possession order based on future events. See Tex. Fam. Code Ann. § 156.101 (West Supp. 2010) (providing for modification of possession order).
[8] Because Clayton's second issue is dispositive, we need not address his first issue claiming that the trial court abused its discretion because the order is not based on factually sufficient evidence. See Tex.R.App. P. 47.1.
[1] Thus, I disagree with the majority's statement that the trial court's ultimate goal is to minimize restrictions placed on a parent's right of possession. See Majority Op. at 721. To the extent that this goal conflicts with the child's best interests, the child's best interests should predominate.
[2] Specifically, the trial court could have reasonably inferred from Natalie's "numerous" statements to Christina that Clayton's alcohol consumption was not as controlled as he had testified.
[3] The cases cited in footnote seven of the majority's opinion are inapposite. See Majority Op. at 723 n. 7. In In re C.A.M.M., the appellate court removed a requirement of supervised visitation because the requirement had not been included in trial court's original custody order and there was no argument made (and apparently no evidence presented) regarding visitation in the father's motion for new trial. 243 S.W.3d 211, 222-23 (Tex. App.-Houston [14th Dist.] 2007, pet. denied). And in In re Pierre, the appellate court reformed an order to delete a drug testing requirement because there was an "absence of any evidence of drug abuse." 50 S.W.3d at 559 (emphasis added).
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Introduction {#s1}
============
In *Saintpaulia ionantha*, colloquially known as the African violet, adventitious shoots can be easily induced from most organs by tissue culture and therefore, it has been used as a model plant for studying adventitious shoot formation (Naylor and Johnson, [@B22]; Arisumi and Frazier, [@B3]; Kukulczanka and Suszynska, [@B12]; Vazquez and Short, [@B32]; Ohki, [@B25]; Nielsen et al., [@B23]; Yang et al., [@B34]). *Saintpaulia* cultivars include many variegated phenotypes in their flowers, such as white-edged leaves or striped petals. In these variegated cultivars, micropropagation, which include adventitious shoot induction by tissue culture techniques, often produce plants with monochromatic or variegated patterns different from their mother plants. These phenomena can be explained by periclinal chimeral separation.
The aerial parts of all vascular plants are composed of cells generated from a shoot apical meristem (SAM). Angiosperm SAMs are composed of several cell layers called L1, L2, and L3 that are numbered from the outermost layer (Satina et al., [@B28]). When cell layers with different genetic backgrounds compose a SAM, this plant is called a periclinal chimera. Basically, cell divisions in L1 and L2 layers are strictly anticlinal in direction and those in the L3 layer are random (Stewart and Dermen, [@B30]). Stable periclinal chimeras can retain their SAM structure through their growth and a variety of color patterns appear in their petals, which are composed by L1 and L2 layers in *Arabidopsis* (Jenik and Irish, [@B10]). In general, adventitious shoot formation is thought to occur from a single cell in many plants (Broertjes et al., [@B4]; Broertjes and Keen, [@B5]; Abu-Qaoud et al., [@B1]). Histological observations at adventitious shoot formation from leaves in *Saintpaulia* also suggested that only their epidermal layer participates in new SAM formation (Naylor and Johnson, [@B22]; Broertjes et al., [@B4]; Broertjes and van Harten, [@B6]; Peary et al., [@B26]; Ohki, [@B25]; Lo, [@B14]; Hosokawa et al., [@B9]). SAM of this single layer originate adventitious buds that must be composed by a single genetic background, and thus their phenotypes often differ from the mother plant, whose SAM is composed by several genetically distinct cell layers. However, there are some exceptions to this rule because in some cases true-to-type patterned plants occurred in adventitious shoots from variegated mother plants (Lineberger and Druckenbrod, [@B13]; Ando et al., [@B2]; Peary et al., [@B26]; Sandall and Lineberger, [@B27]; Nielsen et al., [@B23]), and therefore multiple layer contributions by regeneration have to be supposed in these plants. We should note that a part of these observations mislead the conclusions, because plant materials without evidence of a periclinal chimeral structure were used in the studies. For example, Norris et al. ([@B24]) used variegated cultivars "Tommie Lou," "Bold Dance," "Marge Winters," and "Calico Kitten," and based on their observation that all regenerates from these cultivars showed a true-to-type pattern, they suggested the multi-cellar organization in the ontogenesis of adventitious buds in some cultivars. However, subsequent reports suggested that the variegation patterns in "Tommy Lou" mother plants were not the results of chimeral structure in their SAMs, but their variegation patterns were controlled by genetic elements carried by a single genotype (Marcotrigiano et al., [@B19]). In this case, analysis of variegated pattern in the regenerants would not make sense for determination of the origin of adventitious buds, and such genetic control of variegated patterns was seen in many cultivars of *Saintpaulia* (Marcotrigiano et al., [@B19]). Thus, we have to determine whether a cultivar is periclinal chimera or not only from the visible phenotypes but also by genetic background in each histogen layer of mother plants. Nevertheless, sequential debates on "Tommie Lou" type variegations and possible existences of other types of non-chimeral variegated plants, do not deny the entire previously reported multi-cell layer-derived regenerations. Naylor and Johnson ([@B22]) reported that not only epidermal but also subepidermal cells were actively divided in explants of petiole and lamina during tissue culturing. Based on time-course observations on adventitious formation from petioles, they noted that "Although the shoot has its origin in a single epidermal cell, adjacent epidermal cells and parenchyma cells within the petiole contribute to its final formation" (Naylor and Johnson, [@B22]). Furthermore, the case of shoot regeneration from a synthetic generated chimera using different *Nicotiana* species, shoot regeneration with reorganized structure of the shoot apical meristem sometimes occurs, which indicated multi-cell participation for shoot regeneration (Marcotrigiano and Gouin, [@B17],[@B18]; Marcotrigiano, [@B16]). Espino and Vazquez ([@B7]) observed that cytochimeras, which was mosaic of cells with different ploidy levels, could be obtained by colchicine treatment followed by adventitious bud induction. These reports strongly suggest the multiple cell layer contribution for adventitious bud organogenesis in some cases, however, the factors that determine true-to-type regeneration from chimeral plants are not understood.
To address this question, we decided to revisit a histological analysis on adventitious shoot formation using chimeral *Saintpaulia* cultivars with rigorous evidences that they were putative chimeras. We selected three cultivars, "Kaname," "Concord," and "Monique." "Kaname" has pink petals with a blue stripe in the center. Our previous study indicated that the pink petal portion of "Kaname" which was derived from the L1 layer, had a mutated nonfunctional *flavonoid 3*′*, 5*′ *hydroxylase* (*SiF3*′*5*′*H*) on their genome, while the inner layer had functional *SiF3*′*5*′*H*. All of their adventitious buds produced monochromatic pink flowers, indicating that only the epidermis layer contributed to adventitious bud ontogenesis in this cultivar (Yang et al., [@B34]). This type of chimera separation was consistent with many other studies (Naylor and Johnson, [@B22]; Broertjes et al., [@B4]; Broertjes and van Harten, [@B6]; Peary et al., [@B26]; Ohki, [@B25]; Lo, [@B14]; Hosokawa et al., [@B9]). On the other hand, we selected "Concord" and "Monique," in which a true-to-type pinwheel can be propagated at a relatively high frequency even through adventitious shoot regeneration. These two cultivars were considered to be ideal materials for investigating factors affecting a multi-cell layer contribution to adventitious shoot formation. In this study, we confirmed that "Concord" and "Monique" had periclinal chimera structures by analyzing their genetic background. Then, we compared their flower color separations and adventitious shoot formation histology to those of "Kaname." Here, we propose that cell division activities in the epidermal layer, which is determined by the genotype of the layer, are strongly correlated with ontogenesis of true-to type chimeral shoot regeneration.
Materials and methods {#s2}
=====================
Plant material
--------------
*Saintpaulia* stripe cultivars "Kaname," "Concord," and "Monique" were used (Figures [1A,D,G](#F1){ref-type="fig"}). "Kaname" has pink petals with a blue stripe in their center and "Concord" and "Monique" have white petals with blue stripes in their center. Mother plants and *in vitro*-regenerated plants were transplanted into 270 ml plastic pots containing mixed soil, vermiculite: peat moss: perlite = 5: 2: 3 (v/v/v), the pH of which was adjusted to 6--7 with dolomite. The light intensity of the greenhouse was controlled at around 250 μmol m^−2^ s^−1^ or less by covering with cheesecloths. The greenhouse temperature was maintained within 17°C--35°C by window ventilation and heating. Irrigation was carried out by water mist for 5 min at 9:00 a.m. at a rate of about 50 ml water per pot. Every other week, 50 ml of fertilizer (NPK = 6-10-5, Hyponex stock, Hyponex Japan, Japan) at 1/500 dilution was given while the temperature was adjusted to about 20°C to avoid a rapid leaf temperature drop which induces injury (Maekawa et al., [@B15]; Yun et al., [@B35]; Yang et al., [@B33]). Also, once in 2 months, 2--3 grains of fertilizer IB Kasei (NPK = 10-10-10, Jaycam Agri Co., Ltd., Japan) was added to each pot.
{#F1}
Induction of regenerated plants from striped cultivars
------------------------------------------------------
Leaf blades of "Concord" and "Monique" mother plants were sterilized for 30 min with sodium hypochlorite (0.5% active chlorine) at around 20°C to avoid a rapid leaf temperature drop. Leaves were rinsed three times with 20°C sterile distilled water and cut into 1 × 1 cm squares with a sterile razor blade. They were plated on modified Murashige and Skoog (MS) ([@B21]) medium containing benzyladenine (BA) 0.5 ppm, naphthalene acetic acid (NAA) 0.1 ppm, sucrose 3%, and solidified with 0.3% gellan gum. The pH of the medium was adjusted to 5.8 before autoclaving and after autoclaving the medium was poured into sterilized plastic dishes (9 cm ϕ). Culture was conducted in the plastic petri dishes of 9 cm in diameter and they were incubated under a 16 h day-length provided by cool-white fluorescent tubes (Lifeline, Daylight-type, NEC, Japan) with 60 μmol m^−2^ s^−1^ at 25°C. Clusters of adventitious shoots were divided into small pieces and subcultured on hormone-free modified MS medium until each shoot developed into a 5 cm leaf length. In addition, to obtain adventitious shoots from inner tissues for obtaining shoots without L1, internal tissues of the petioles were excised with a razor and tweezers and cultured in the same manner. The adventitious shoots were transplanted and rooted in a plug tray containing the previously described mixed soil and placed in a greenhouse under high-humidity by intermittent mist treatments. The shoots were then transplanted to 270 ml plastic pots and placed in the temperature and light controlled greenhouse and grown under the same irrigation and fertilization conditions as mentioned previously. When the plants flowered, the number of plants with each flower color and pattern was counted. Furthermore, to investigate the phenotype stability of these regenerated plants, leaf discs of the flowered plants for each phenotype were cultured again and the shoots were grown in the same manner. For flowered plants, each flower color phenotype of all cultivars, including "Kaname" which were cultured at the same time, measurements of plant diameter, largest leaf width, and largest leaf length were taken. Six plants of each flower color phenotype and mother plants (except for the mother plants of "Kaname") from the three cultivars were used for the measurements. The statistical analyses used the multiple comparison test of Tukey-Kramer (*P* = 0.05) for "Concord," and "Monique," or a Student\'s *t*-test for "Kaname" (*P* = 0.05).
Histological observation
------------------------
To observe cell division and SAM formation on the cultured leaf segments of "Kaname," "Concord," and "Monique," the cultured samples were fixed in a formalin-acetic acid-alcohol (FAA) solution (ethanol: formaldehyde: acetic acid: water = 12:1:1:6 v/v/v/v) after 0--18 d of culture and evacuated for several days in FAA. Then, the samples were washed with tap water and dehydrated through a series of different ethanol concentrations. Ethanol in the samples was replaced by a resin solution (Technovit 7100, Heraeus Kulzer, Germany) and then embedded in Technovit 7100 at 25°C according to the manufacturer\'s instructions. The samples were cut into 5 μm-thick sections using a microtome (RM2155, Leica Microsystems, Germany) and the sections were placed onto glass slides. Sections were then stained with 0.05% (w/v) toluidine blue and observed under a VHX digital microscope (Keyence, Japan). The number of cells and total cell number were counted in each epidermal layer and subepidermal layer within seven 2 × 2 mm randomly selected sections 0--14 d after culture for the three selected samples.
High performance liquid chromatography (HPLC) analysis
------------------------------------------------------
Freeze-dried petals were soaked overnight in a methanol-acetic acid-water solution (methanol: acetic acid: water, 4:1:5 v/v/v) to extract the pigments. HPLC analysis was performed using an LC10A system (Shimadzu Co. Ltd., Japan) with a C18 column (Nihon Waters K.K., Japan) maintained at 40°C and a photodiode array detector. The detection wavelength was 530 and 350 nm for anthocyanins and flavones, respectively. Elutant A was 1.5% phosphate dissolved in water and elutant B was 1.5% phosphate, 20% acetic acid, and 25% acetonitrile dissolved in water. The analysis was performed at a flow rate of 1 ml/min and a column temperature of 40°C using a mobile phase gradient starting at 20--85% B over 40 min with 5 min re-equilibration at 20% B. Nine purified *Saintpaulia* pigments were used as anthocyanin standards (Tatsuzawa and Hosokawa, [@B31], Table [1](#T1){ref-type="table"}). To estimate the stopped position of the anthocyanin biosynthesis pathway in "Concord" and "Monique," naringenin or taxifolin was fed to the white petals. One milli mole of naringenin (Sigma-Aldrich, USA) or taxifolin, also known as dihydroquercetin (Sigma-Aldrich), was dissolved in 1% ethanol and applied to the white edges of the petals. Distilled water containing 1% ethanol was used as a control. Just opened petals cut in the middle portion vertically to the midrib were soaked in the solution and incubated at 25°C for 24 h under the light conditions. When the petals were colored, the colored part was cut with a razor and extracted with the same solvent and analyzed by HPLC in order to determine the type of anthocyanin.
######
The main anthocyanins and flavons detetced in each mutant.
**Cultivars, mutant** **Anthocyanins detected by 530 nm** **Flavons detected by 350 nm**
----------------------- ------------------------------------- -------------------------------- ----- ----- ----- ------ ----- ----- ----- ----- ------
Concord blue 0.4 0.3 1.1 0.1 5.8 81.7 0.6 -- -- 1.9 39.4
Concord white 2.1 -- 0.7 -- 6.2 78.0 -- -- -- 4.4 36.9
Monique blue 0.1 0.1 0.9 0.1 4.6 89.2 0.1 0.1 0.1 2.9 45.4
Monique white -- -- 0.7 0.1 1.6 82.0 0.1 0.9 -- 4.6 48.2
*Pg, pelargonidin; Pn, peonidin; Mv, malvidin; R, rutinose; G, glucose; Ac, acetic acid; Lt, luteolin; Ap, apigenin; Glucuro, glucuronic acid*.
*All pigments were extratcted with MAW*.
*indicates retention time (min)*.
*The structure of Lt 4′-Glucuro (Luteolin 4′-glucuronide) purified from dried mixed flowers (over 10 cvs) (20 g) was confirmed on the analysis of its ^1^H (400 MHz), ^13^C (100 MHz), and 2D (COSY, NOESY, ^1^H-^13^C HMQC, and ^1^H-^13^C HMBC) NMR (JMN AL-400, JEOL Ltd., Japan) spectra in DMSO-d~6~, as well as their high resolution fast atom bombardment mass spectra (HR-FABMS) (LMS-700, JEOL, Ltd.). The ^1^H NMR spectrum of "Lt 4′-Glucuro" exhibited six aromatic proton signals of luteolin (see below) and five signals of glucuronic acid. The anomeric proton signal of glucuronic acid was observed at 5.10 (d, J = 7.1 Hz). The bonding of these compounds was confirmed by NOESY and ^1^H-^13^C HMBC experiment. The NOEs between H-1 (5.10) of glucuronic acid and H-5′ (7.18) of luteolin were observed. Moreover, the signal of the anomeric proton of glucuronic acid correlated with that of the C-4′ (148.2) carbon of luteolin in the HMBC spectrum. These results suggested that OH-4′ of luteolin was bonded with glucuronic acid. Therefore, the structure was elucidated to be luteolin 4′-glucronide*.
*Luteolin 4′-glucronide: UV-Vis (λmax nm): MeOH 333,287sh,268, +NaOMe 353,317,273, +AlCl~3~ 375sh,352,291sh,277,252sh, +AlCl~3~/HCl 376sh,346,289sh,280,247sh, +NaOAc 333, 271, +NaOAc/H3BO3 334,270. HR-FABMS \[M+H\]^+^, calc. for C~21~H~19~O~12~: 463.0877. found: 463.0878. 1H NMR: d luteolin: 6.80 (brs, H-3), 6.20 (d, J = 2.0 Hz, H-6), 6.84 (d, J = 2.0 Hz, H-8), 7.49 (d, J = 2.2 Hz, H-2\'), 7.18 (d, J = 8.8 Hz, H-5′), 7.52 (dd, J = 2.2, 8.8 Hz, H-6′), glucuronide: 5.10 (d, J = 7.1 Hz, H-1″), 3.38 (t, J = 9.0 Hz, H-2″), 3.35 (t, J = 9.0 Hz, H-3″), 3.43 (t, J = 9.0 Hz, H-4″), 3.96 (t, J = 9.5 Hz, H-5″). 13C NMR:d luteolin: 163.3 (C-2), 104.1 (C-2), 181.9 (C-4), 161.5 (C-5), 99.0 (C-6), 164.4 (C-7), 94.1 (C-8), 157.4 (C-9), 103.9 (C-10), 125.0 (C-1′), 113.9 (C-2′), 147.1 (C-3′), 148.2 (C-4′), 115.9 (C-5′), 118.6 (C-6′), glucuronide: 100.5 (C-1″), 73.0 (C-2″), 75.3 (C-3″), 71.5 (C-4″), 75.5 (C-5″), 170.3 (COOH)*.
Ultraviolet visible (UV-vis), high resolution fast atom bombardment mass spectra (HR-FABMS), and nuclear magnetic resonance (NMR) measurements
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UV-vis spectra for purified flavone was recorded on a UV-vis multi-purpose spectrophotometer (MPS-2450, Shimadzu Co. Ltd.) operated as a double-beam instrument in MeOH (from 200 to 500 nm). HR-FABMS were obtained in a positive ion mode using a 1:1 mixture of dithiothreitol and 3-nitrobenzyl alcohol as a matrix with the JMS-700 MS station mass spectrometer (JEOL Ltd., Japan). NMR spectra were recorded on a JNM AL-400 spectrometer (JEOL Ltd.) at 400 MHz for ^1^H spectra and 100 MHz for ^13^C spectra in dimethyl sulfoxide (DMSO)-*d*~6~. Chemical shifts are reported relative to DMSO (2.5 ppm) and coupling constants (*J*) are in Hz.
Genetic analysis
----------------
The extraction of total RNA was performed by the RNeasy Plant Mini Kit (QIAGEN, Germany) and subjected to reverse transcription (RT) using an oligo-(dT)~20~ primer and ReverTra Ace (TOYOBO, Japan) according to the manufacture\'s instruction. RNA concentrations were adjusted to 100 ng/μl by spectrophotometer (Nanodrop, Thermo Scientific, USA). In "Concord," the expression analysis was performed using RNA extracted from petals and leaves of white and blue monochromatic color plants (Figures [1E,F](#F1){ref-type="fig"}). In "Monique," the central part (the colored part of the petal) and the peripheral part (the non-colored part) were cut with a razor and RNA was extracted from each area. For full length *flavanone 3-hydroxylase* (*SiF3H*; LC269962) expression in "Monique," the petals and leaves of monochromatic plants (Figures [1H,I](#F1){ref-type="fig"}) were used for RNA extraction.
For the expressions of *SiCHS-A* (DQ788862): *chalcone synthase-A, SiF3H* (LC269962), *SiDFR* (LC269960): *dihydroflavonol 4-reductase, SiANS* (LC269961): *anthocyanidin synthase*, as genes coding enzymes on the anthocyanin biosynthesis pathway and *SiDEL* (LC269959): *DELILA*/*JAF13* (*a basic helix-loop-helix*), *SiMyb2* (LC269957), *SiWDR1* (LC269958), and *SiPAC* (LC269956) as transcriptional factors for anthocyanin biosynthetic genes were amplified by specific primers (Table [S1](#SM2){ref-type="supplementary-material"}) which were designed from their coding sequences. *SiActin* (AB596843) was used as the reference gene.
For DNA extraction, the DNeasy Plant Mini Kit (QIAGEN) was used according to the manufactures\' instructions. Moreover, in order to extract DNA from the L1 layer, trichomes were collected by a razor blade under a stereomicroscope and the DNA was extracted by mixing with 2 ml of buffer AP1 (QIAGEN) in plastic tubes and extracted according to the manufactures\' instructions. Also, the epidermis-removed petiole was used as a sample in order to obtain DNA from internal layers. DNA concentrations were adjusted below 2 ng/μl by spectrophotometer (Nanodrop, Thermo Scientific). All PCR/RT-PCR mixtures contained 1 μl of template DNA (at a maximum 1--2 ng), 0.1 μl of Blend *taq* (TOYOBO), and 0.2 μM of forward and reverse primers at a final volume of 10 μl according to the manufacture\'s instruction. The program was set at 94°C for 2 min, followed by 35 cycles at 94°C for 30 s, 55--60°C for 30 s depending on the value of the melting temperature of each primer set, and 72°C for 10--60 s depending on the length to be amplified. All PCR products were electrophoresed in 1% agarose gel and signals were detected under a UV-illuminator.
The 5′ flanking region sequence of *SiWDR1* in blue and white "Concord" mutants was determined by a commercial kit (RightWalk kit FK, BEX, Japan) and inverse PCR. According to the manufactures\' instructions, genomic DNA (total 1 μg) of "Concord" leaves of monochromatic blue flowers was digested by *Xba* I (TaKaRa Bio, Japan) and ligated with adaptors supplied by the kit. The first PCR was conducted with WDR40 Walk R1st primer (Table [S1](#SM2){ref-type="supplementary-material"}) with WP-1 (supplied by the kit) and the second PCR was conducted by WDR40 Walk R2nd (Table [S1](#SM2){ref-type="supplementary-material"}) and WP-2 (supplied by the kit). The amplified product was cloned into pTAC-1 vector (BioDynamics Laboratory Inc., Japan) and sequenced by a 3,100 genetic analyzer (ABI PRISM, USA) after the reaction with a BigDye terminator v3.1 cycle sequencing kit (ABI PRISM). Genomic DNA (total 1 μg) of "Concord" blue and white mutants were digested with *Eco*RI (TaKaRa Bio) and self-ligated with 80 units of T4 DNA ligase (NEW ENGLAND BioLabs, USA). The ligated DNA was precipitated with ammonium acetate and ethanol and used for PCR. For the first PCR, 1st Primer-F aroundA and 1st Primer-R aroundA were used and for the nested PCR, B-F and 2nd Primer-R aroundA were used (Table [S1](#SM2){ref-type="supplementary-material"}). The product was cloned and sequenced as mentioned before. From the DNA sequence data of monochromatic blue and white flower plants, we could design primers for the determination of blue or white mutants, BF and BR primers for the blue mutant, and B-F and WDR white specific-R primers for the white mutant (Table [S1](#SM2){ref-type="supplementary-material"}).
To determine full length mRNA sequences of *SiF3H* for "Monique," the GeneRacer™ Kit (Invitrogen, USA) was used according to the manufactures\' instructions and a 5′-Full RACE Core set (TaKaRa Bio). The amplified products were cloned and sequenced as mentioned before. From the sequence data (LC2269962), primers for the total length amplification were designed and used for RT-PCR and genomic PCR using RNA/DNA of monochromatic blue flower plants. From these sequence data, the exon and intron structure of DNA of monochromatic blue flower plants was determined.
Results {#s3}
=======
Flower color separations in the regenerants of two *Saintpaulia* cultivars
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Flowers of adventitious shoots from leaf laminas of "Concord" and "Monique" exhibited three types of flowers. In "Concord" white monochromatic-colored plants (L1 phenotype) (Figure [1E](#F1){ref-type="fig"}) were observed at the highest frequency (75.6%) followed by blue monochromatic-colored plants (L2 phenotype) (20.7%) (Table [2](#T2){ref-type="table"}, Figure [1F](#F1){ref-type="fig"}). In "Monique" white monochromatic-colored plants (L1 phenotype) (Figure [1H](#F1){ref-type="fig"}) were observed at the highest frequency (45%), and 25% of regenerates were blue monochromatic plants (L2 phenotype) (Table [2](#T2){ref-type="table"}, Figure [1I](#F1){ref-type="fig"}). Notably, three of the 82 "Concord" plants (3.7%) and six of the 20 "Monique" plants (30%) exhibited the same striped pattern as their mother plant (Table [2](#T2){ref-type="table"}). On the other hand, the striped patterned flower mutant opposed to mother plants was not observed. When epidermis-peeled petioles of striped mother plants were used as explants, all flower color patterns in adventitious shoots were monochromatic and their color was identical to the center portion of the mother plant (Table [2](#T2){ref-type="table"}). This result indicated that in both cultivars, inner cells did not pose genetic elements that produce white petals, and thus edged colors in mother plants had their origins in epidermal cells. Moreover, when monochromatic-colored regenerants from three cultivars were again used as explants for adventitious shoot regeneration, flower traits that developed in second regenerants retained the same flower traits as their first regenerants (Table [3](#T3){ref-type="table"}). This result indicated that monochromatic-colored characteristics were stable during the adventitious shoot regeneration process, and two types of monochromatic-colored regenerants from "Concord" and "Monique" explants were genetically distinct from each other.
######
Phenotypes of regenerated plants from different tissues of two cultivars.
**Cultivars** **Explants** **Number of plants (%)**
--------------- ---------------------------------------------- -------------------------- ----------- ----------- ---------
Concord Leaf disc 82 62 (75.6) 17 (20.7) 3 (3.7)
Inner tissue[^a^](#TN3){ref-type="table-fn"} 20 0 (0) 20 (100) 0 (0)
Monique Leaf disc 20 9 (45) 5 (25) 6 (30)
Inner tissue 23 0 (0) 23 (100) 0 (0)
*epidermis-peeled petiole was used*.
*the monochromatic white flower, which is the same as the petal edge color*.
*the monochromatic blue flower, which is the same as the petal edge centor*.
*the pinwheel phenotype same as mother plants*.
######
Phenotypes of regenerated plants from leaf discs of each monochormatic flower mutant of two cultivars.
**Cultivars** **Flower color mutant** **Number of plants (%)**
--------------- ------------------------- -------------------------- ---------- ---------- -------
Concord Blue 80 0 (0) 80 (100) 0 (0)
White 30 30 (100) 0 (0) 0 (0)
Monique Blue 70 0 (0) 70 (100) 0 (0)
White 80 80 (100) 0 (0) 0 (0)
*the monochromatic white flower, which is the same as the petal edge color*.
*the monochromatic blue flower, which is the same as the petal edge centor*.
*the pinwheel phenotype same as mother plants*.
Determination of anthocyanins in petals
---------------------------------------
Seven and nine anthocyanin derivatives were detected from "Concord" and "Monique" petals, respectively (Table [1](#T1){ref-type="table"}) by HPLC analysis. The anthocyanidin moiety, malvidin, was revealed to be the main anthocyanidin in both cultivars (Table [1](#T1){ref-type="table"}). Also, luteolin 4′-glucronide and apigenin 4′-glucronide were the main flavones for both cultivars (Table [1](#T1){ref-type="table"}). The anthocyanin and flavone compositions in different mutants were not different (Table [1](#T1){ref-type="table"}).
Determination of candidate genes responsible for pigmentation variations in "Concord"
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When naringenin or taxifolin was fed to petals of white "Concord" mutants, pigment accumulation in the edge of the cut surface was not observed (Figure [2B](#F2){ref-type="fig"}), which indicated that steps after DFR either stopped or several steps in anthocyanin biosynthesis were stopped. The expressions of *SiCHS-A, SiF3H, SiDFR*, and *SiANS* in "Concord" petals were analyzed and the results showed that expressions of these genes, especially *SiF3H, SiDFR*, and *SiANS*, were lower in monochromatic white mutants compared to monochromatic blue mutants (Figure [3A](#F3){ref-type="fig"}). RT-PCR transcriptional factor results showed that *SiWDR1* expression in leaves was not detected in monochromatic white mutants and only a trace signal was detected monochromatic white petals (Figure [3A](#F3){ref-type="fig"}). Then, the upper stream of the *SiWDR1* DNA coding sequence was determined. In monochromatic blue mutants, SNPs upstream of the coding region indicated two types of *SiWDR1* sequences, hereafter called *SiWDR1-1* and *SiWDR1-2* (Figure [4](#F4){ref-type="fig"}). In monochromatic white mutants, we could not detect targeted *SiWDR1-1* and *SiWDR1-2* sequences when we used primers that amplified the 5′ flanking region. We also determined the sequence of the 5′ flanking region of monochromatic white mutants and revealed that the upstream region of *SiWDR1-2* was connected to an unknown sequence (Figure [3B](#F3){ref-type="fig"}). We designed a new primer, WDR white specific-R, which is located at the unknown sequence, and amplified the white specific sequence in combination with the B-F primer located at *WDR1* 5′ flanking region (Figure [3B](#F3){ref-type="fig"}). This combination successfully amplified the white genome but not blue genome (Figure [3C](#F3){ref-type="fig"}). On the other hand, a B-F and B-R combination amplified only the blue genome. The amplified sequences by A-F and B-R primers in blue mutants contains an SNP, A or G, which indicated *SiWDR1-1* and *SiWDR1-2*, respectively (Figure [4](#F4){ref-type="fig"}). The amplified sequence by A-F and WDR white specific-R contained the SNP "G," which indicates the amplified sequence is *SiWDR1-2* (Figure [4](#F4){ref-type="fig"}). And trichome, which was originated from L1 of the mother plant, did not have the product by B-F and B-R primers that was in the mother plant (Figure [3](#F3){ref-type="fig"}). On the other hand, the inner cells that were derived from L2 or L3 of mother plants had a PCR product with B-F and B-R products, but did not have a product by B-F and WDR white specific-R (Figure [3C](#F3){ref-type="fig"}). The total leaves and meristems of mother plants have both products (Figures [3C,D](#F3){ref-type="fig"}). From these results, we could conclude that the mother plant has a periclinal chimeral structure that has L1 without functional SiWDR1 and inner layers with functional SiWDR1.
{ref-type="table"}. SiCHS-A, chalcone synthase-A; SiCHI, chalcone isomerase; SiF3H, flavone 3-hydroxylase; SiF3′ 5′H, flavonoid 3′ 5′-hydroxylase; SiF3′H, flavonoid 3′-hydroxylase; SiDFR, dihydroflavonol 4-reductase; SiANS, anthocyanidin synthase; Si3GT, 3-glucosyltransferase; SiRT, rhamnosyltransferase; SiAT, acyltransferase; Si5GT, 5-glucosyltransferase; SiA3′MT, anthocyanin 3′-methyltransferase; SiA5′MT, anthocyanin 5′-methyltransferase; Pg 3AcR, pelargonidin 3-acyl-rutinoside; Pg 3AcR5G, pelargonidin 3-acyl-rutinoside-5-glucoside; Pg 3R5G, pelargonidin 3-rutinoside-5-glucoside; Mv 3AcR5G, malvidin 3-acyl-rutinoside-5-glucoside; Mv 3R5G, malvidin 3-rutinoside-5-glucoside; Cy 3AcR, cyanidin 3-acyl-rutinoside; Pn 3AcR, peonidin 3-acyl-rutinoside; Pn 3AcR5G, peonidin 3-acyl-rutinoside-5-glucoside; Pn 3R5G, peonidin 3-rutinoside-5-glucoside. **(B)** The results of the feeding experiments of two precursors to the petals of "Concord" and "Monique." The left column is the result for "Concord" and the right column is "Monique." In the upper row, the results of the control group (1% ethanol), naringenin, and taxifolin are shown. Petals were photographed after incubating at 25°C for 24 h in light conditions. Arrow represents the colored parts. It seems that the brown stained areas observed in all samples were not caused by precursors but by ethanol. **(C)** HPLC result of colored part of "Monique" by taxifolin feeding. The number above the peak shows the retention time and the names next to each peak are the substances estimated from the absorbance of each peak.](fpls-08-01749-g0002){#F2}
{#F3}
{#F4}
Determination of candidate genes responsible for pigmentation variations in "Monique"
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Feeding naringenin to the petals of white edge "Monique" striped petals did not alter their pigmentation, but when fed taxifolin, the white petals turned reddish (Figure [2B](#F2){ref-type="fig"}). From these results, the candidate gene for the absence of malvidin derivatives in the white-colored phenotype was supposed to be an unfunction of F3H (Figure [2A](#F2){ref-type="fig"}). Anthocyanin from the portion fed taxifolin was revealed to be malvidin 3-acyl-rutinoside-5-glucoside, which is the main anthocyanin of this cultivar, and in this treatment, peonidin 3-acyl-rutinoside-5-glucoside was obtained (Figure [2C](#F2){ref-type="fig"}). The expressions of all anthocyanin biosynthetic genes except *SiF3H* were not different between monochromatic blue and white flower color mutants (Figure [5A](#F5){ref-type="fig"}). So, we determined the full length of *SiF3H* by 5′ and 3′ RACE. Using primers to amplify the full length of *SiF3H* mRNA (Table [S1](#SM2){ref-type="supplementary-material"}), one signal on the electrophoresed gel was detected in the monochromatic blue mutant, however, two bands that were different sizes compared to the blue one were detected. These two sequences have a 63 bp insertion (LC322156) and 161 bp deletion (LC322157) (Figure [5C](#F5){ref-type="fig"}, Figure [S1](#SM1){ref-type="supplementary-material"}), respectively. These two sequences in the monochromatic white mutant did not code complete protein sequences by stop codon generations (Figure [S1](#SM1){ref-type="supplementary-material"}). The genomic PCR results using full length primers in monochromatic white mutants In striped petals showed no *SiF3H* signal band (Figure [5D](#F5){ref-type="fig"}). The amplified product by the full length primers in the monochromatic blue mutant was sequenced and it was determined that the band was 2,752 bp. This sequence has two introns and three exons which completely coincided with the full length mRNA sequence of monochromatic blue mutants with 1,107 bp (Figure [5B](#F5){ref-type="fig"}). The DNA extracted from leaf trichomes of the mother plants were applied to genomic PCR of *SiF3H*, and the signal was not detected but was detected from inner tissues of petioles (Figure [5E](#F5){ref-type="fig"}). And, the full length *SiF3H* signal was detected in the mother plant. From these results, we can conclude that the mother plant has a periclinal chimeral structure which has L1 without functional SiF3H and inner layers with functional SiF3H.
{ref-type="fig"}. **(B)** The diagram of *SiF3H* DNA (upper) and mRNA (lower) from the DNA of a blue flower mutant. The arrows on the lines indicate the primers used for **(C--E)**. The numerical characters on the figure indicate the position of splicing from nucleotide "A" of the start codon ATG. **(C)** RT-PCR results of full length of *SiF3H* mRNA. (1) Leaf of a blue flower mutant, (2) petal of a blue flower mutant, (3) leaf of a white flower mutant, (4) petal of a white flower mutant. On the lane of the blue flower mutant, a 1,107 bp band was observed and on the lane of the white flower mutant, 1,170 and 946 bp were observed. The lengths were determined by sequence analysis. **(D)** Genomic PCR for full length *SiF3H* DNA from leaves of the mother plant (1), blue flower mutant (2), white flower mutant (3), and control (water). **(E)** genomic PCR for full length *SiF3H* DNA from a total leaf of the mother plant (1), trichome from mother plants which were derived from L1 (2), inner cells of petioles derived from L2 and L3 (3), and control (water; 4). **(D,E)** primers for actin were used for actin DNA proliferation (lower panel).](fpls-08-01749-g0005){#F5}
Observation of cell division at the formation of adventitious shoots
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To determine the origins of adventitious shoots, histological observations were made on explants of "Kaname," "Concord," and "Monique" mother plants. At the start of culture, differences in leaf structures were not observed among the three cultivars and we could observe one epidermal and one subepidermal layer at the adaxial surface (Figures [6A,E,J](#F6){ref-type="fig"}). In "Kaname," epidermal cells divided actively in the adaxial side 8 and 10 d after culture (Figures [6B,C](#F6){ref-type="fig"}) and shoot formation occurred in the epidermal cells at 14 d after culture (Figure [6D](#F6){ref-type="fig"}). In "Concord" explants, first cell divisions were observed 5 d after culture (Figure [6F](#F6){ref-type="fig"}), and at 12 d after culture, cell division at the epidermis was not so active and active cell division was instead observed at the subepidermal layer (Figure [6G](#F6){ref-type="fig"}). After that, cell clusters that had originated from the subepidermal layer pushed up the epidermis in "Concord" at 18 d after the culture (Figures [6H,I](#F6){ref-type="fig"}). In "Monique," active cell division was also observed at the subepidermal layer rather than the epidermis10 d after culture (Figures [6K,L](#F6){ref-type="fig"}). Then, the number of divided cells in true-to-type "Kaname" and "Concord" explants were examined. In "Kaname," the number of divided cells in the epidermis was much higher than those in subepidermal cells at 14 d after culture (Figure [7](#F7){ref-type="fig"}). In "Concord," the number of cells in the epidermis did not increase during 14 d of culture. Instead, the number in subepidermal cells was a little higher than those in epidermal cells (Figure [7](#F7){ref-type="fig"}).
{#F6}
{#F7}
The growth of plants regenerated from the epidermis and subepidermis
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In "Kaname," growth differences were not observed between monochromatic pink and blue mutants (Table [4](#T4){ref-type="table"}, Figures [1B,C](#F1){ref-type="fig"}). In "Concord" and "Monique," obvious growth differences were observed between the three types of plants; plant diameter and leaf sizes were smaller in epidermal-derived plants (monochromatic white) than inner layer-derived plants (monochromatic blue), and the mother plants had middle characteristics of these epidermis and inner-tissue originated plants (Table [4](#T4){ref-type="table"}, Figure [8](#F8){ref-type="fig"}).
######
The plant growth characteristics of mutants derived from each histogen layer of three cultivars.
**Cultivars** **Type** **Plant diameter (cm)** **Largest leaf width (cm)** **Largest leaf length (cm)**
--------------- ---------- ------------------------- --- ----------------------------- --- ------------------------------ ---
Kaname Original -- -- --
Blue 28.5 a 5.0 a 5.7 a
Pink 27.1 a 4.9 a 5.6 a
Concord Original 14.7 b 3.2 b 3.8 b
Blue 23.1 a 5.1 a 5.2 a
White 14.7 b 2.8 b 3.2 b
Monique Original 14.1 b 4.1 a 4.4 a
Blue 16.3 a 4.4 a 5.1 a
White 11.6 c 3.4 a 3.3 b
*Data of original plant of "Kaname" were not collected because we could not propagate original plants*.
*The different alphabetical characters indicate the statistical differences between each cultivar*.
*For "Kaname" student t (p \< 0.05) was used for 4 plants on each phenotype*.
*For "Concord" and "Monique," Tukey-Kramer test (p \< 0.05) was used for 6 and 4 plants, respectively*.
{#F8}
Discussion {#s4}
==========
"Kaname," "Concord," and "Monique" are periclinal chimeras
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In *Saintpaulia*, there are bi-color cultivars, which have two different petal colors in the central and peripheral parts. This color-type cultivar is called pinwheel. When such cultivars are propagated by tissue culture, regenerated plants are separated into monochromatic flower color individuals (Lineberger and Druckenbrod, [@B13]; Ando et al., [@B2]; Peary et al., [@B26]; Sandall and Lineberger, [@B27]; Nielsen et al., [@B23]). However, in some cases the propagated plants maintain the pinwheel patterns. We should consider two causes for this result. One is because the striped pattern expression of some cultivars is caused by mechanisms other than periclinal chimera separation, e.g., by epigenetic instability. The other cause is because shoot regeneration is multi-celled in origin. Previous studies determined whether the patterned plants were periclinal chimeras or not based on their appearance, and estimated the origin of adventitious shoots also from the appearance of regenerated individuals. However, if a stripe pattern is formed by a mechanism other than a periclinal chimera, the origin of the adventitious shoots cannot be specified. Therefore, we first needed to obtain evidence that the specific origin of the mother plant was a periclinal chimera with a genetic mutation in the histogen layer.
From the HPLC result of "Concord," the monochromatic white mutant, the anthocyanin and flavones greatly decreased but their composition did not be changed (Table [1](#T1){ref-type="table"}). Feeding taxifolin did not induce anthocyanin biosynthesis in "Concord" petals, meaning that after DFR step it was at least un-functioned (Figures [2A,B](#F2){ref-type="fig"}). According to the reports on anthocyanin biosynthesis, a multistep inexpression of genes was considered to be attributed to transcription factors (Koes et al., [@B11]). The decreased expressions of the four genes analyzed indicated that a transcriptional factor, WDR1, was supposed to be the strong candidate for the white phenotype (Figure [3A](#F3){ref-type="fig"}). The sequence of the trace band observed in white petals (Figure [3A](#F3){ref-type="fig"}) had nine SNP differences from the amplified *SiWDR1-1* and *SiWDR1-2* sequences using same primers (data not shown), and this product was not petal-specific because the direct sequence of RT-PCR product contained the nine SNPs sequences in addition to the *SiWDR1* sequence (data not shown). Suppression of these enzymatic genes, including *SiANS* which is after the *SiDFR* step, was consistent with the taxifolin feeding experimental result. SiWDR1 plays the most important role for anthocyanin biosynthesis by complexing with other transcriptional factors and by regulating the expression of several enzymatic genes on the anthocyanin biosynthesis pathway (Koes et al., [@B11]). In "Concord," two *SiWDR1* genes were determined in blue-type cells, one of which, the 5′ flanking region of *SiWDR* (*SiWDR1-2*), was connected to an unknown sequence (Figure [3B](#F3){ref-type="fig"}). This unknown sequence was also in blue mutant cells, but the 5′ flanking region of this unknown sequence was quite different from the white mutant cells (data not shown). This indicates that the white mutant *SiWDR1-2* lost its function by spontaneous genetic rearrangement with other DNA sequence. Further, another *SiWDR* (*SiWDR1-1*) had disappeared from white mutant cells (Figure [4](#F4){ref-type="fig"}). We cannot discuss why the *SiWDR1-1* disappeared from the genome, but one hypothesis is that these two *SiWDR1* were located at a same locus and the spontaneous rearrangement of *SiWDR1-2* and the disappearance of *SiWDR1-1*occurred simultaneously.
In "Monique," HPLC results revealed that this cultivar also decreased anthocyanin and flavone accumulation, but their composition was not changed (Table [1](#T1){ref-type="table"}). This also indicated that upstream of the anthocyanin biosynthesis pathway is inactivated. Only feeding taxifolin to petals induced anthocyanin biosynthesis, which indicates that the steps after F3′5′H and DFR were normally activated and malvidin 3-acyl-rutinoside-5-glucoside (Table [1](#T1){ref-type="table"}), the main anthocyanin of the blue area of "Monique" petals, were detected from the painted area by HPLC, which indicated that the step after SiF3′5′H was active (Figures [2A,C](#F2){ref-type="fig"}). Biosynthesis of peonidin 3-acyl-rutinoside-5-glucoside was observed in the taxifolin treatment, which indicates that SiF3′H was also active (Figure [2A](#F2){ref-type="fig"}). As expected in this cultivar, DNA sequence differences were observed in *SiF3H* (Figure [5](#F5){ref-type="fig"}). Monochromatic white mutant full length genomic *SiF3H* was not amplified by ordinal PCR (Figure [5](#F5){ref-type="fig"}), but the long PCR method was conducted using the same template and about an 8 kb band was observed. We did not get the sequence of the band, but this band evoked an inserted sequence such as a transposable element. From these evidences, we concluded that "Concord" and "Monique" were periclinal chimeras, the same as our previous study on "Kaname" which has a mutated SiF3′5′H in the L1 layer.
In addition to these genetic evidences, the results of repetition of shoot regeneration from the monochromatic-colored mutants, in which the monochromatic color expression was stable, supports the conclusion that the used cultivars were periclinal chimeras and allowed us to determine adventitious shoot origin.
Does shoot formation occur from single or multi-cell layers in *Saintpaulia*?
-----------------------------------------------------------------------------
We found that the origin of shoot formation was different depending on the cultivar. Many histological observations have revealed that shoot formation occur from the epidermis (Naylor and Johnson, [@B22]; Arisumi and Frazier, [@B3]; Broertjes and Keen, [@B5]; Ohki, [@B25]; Hosokawa et al., [@B9]). In *Saintpaulia*, epidermal cells are easier to divide and form new meristems. Yang et al. ([@B34]) revealed that 100% of "Kaname" shoots were a monochromatic flower color and were the same as the epidermal color phenotype which was derived from the L1 layer in the mother plant. On the other hand, shoot formation of "Concord" and "Monique" were solely from L1 or L2 and sometimes from both L1 and L2 (Table [2](#T2){ref-type="table"}). Therefore, it is certain that adventitious shoots are formed by multiple cells derived from multiple histogen layers in these cultivars.
However, a new question arises as to what determines the origin of shoot formation. In "Kaname," all of the regenerated shoots from the leaves of mother plants developed monochromatic pink flowers which had a nonfunctional *SiF3*′*5*′*H* allele, indicating that all adventitious shoots were regenerated from the epidermis. This type of chimera separation has been frequently reported (Abu-Qaoud et al., [@B1]). The mutation of *SiF3*′*5*′*H* will not reduce their growth vigor (Table [4](#T4){ref-type="table"}). Before cell division starts in subepidermal tissues, meristem formation occurred at the epidermal cells (Figure [9A](#F9){ref-type="fig"}). In contrast to this case, cell division of the epidermis in "Concord" and "Monique" was slow and rather it was observed that the subepidermal cells divided (Figures [6](#F6){ref-type="fig"}, [7](#F7){ref-type="fig"}). Regenerant "Concord" and "Monique" leaves developed monochromatic white, monochromatic blue, and striped flowers, and more than 20% of shoots of total shoots were derived from subepidermal tissues in both cultivars (Table [2](#T2){ref-type="table"}). Histological observations in cultured explants supported this idea, and active cell division was observed in subepidermal cells in "Concord" and "Monique" during culture (Figure [6](#F6){ref-type="fig"}). A comparative histological analysis among "Kaname," "Concord," and "Monique" suggested that a relatively high frequency of cell division activities in subepidermal cells explained the occurrence of non-chimeral, inner layer type regenerants from leaf explants. In conclusion, when the cells with a weak vigor cover vigorous cell layers, inner cells start to divide before the epidermal cells and form new SAMs by pushing up the L1 layer (Figures [6](#F6){ref-type="fig"}, [9A](#F9){ref-type="fig"}). Sometimes, the inner cells burst L1 cells during the formation of SAMs, in this instance the genotypes of shoots were L2 blue flowered plants in "Concord" and "Monique." In some cases, L2 cells formed SAMs while pushing up the L1 layer, in this instance the shoot genotype was chimeral, the same structure as the mother plant. In some cases, the L1 cell layer divided solely and formed SAMs, in this instance the shoot genotype is the L1 layer, the white flower plants in these cultivars. Shoot regeneration occurs from the most vigorous cell layers, L1 in *Saintpaulia*, but in cases where some mutations decrease cell vigor in the cell layer, adventitious shoots regenerate from other cell layers solely or include some cell layers (Figure [9A](#F9){ref-type="fig"}).
{#F9}
The third question is what kind of phenotype determined the cell division activities in those cultivars. In the "Kaname" mother plant, the structure of its SAM was considered to be composed by L1 carrying mutated, nonfunctional *SiF3*′*5*′*H* and inner layers carrying non-mutated, functional *SiF3*′*5*′*H*. All of the regenerated shoots from the leaves of mother plants developed monochromatic pink flowers which had a nonfunctional *F3*′*5*′*H* allele, indicating that all the adventitious shoots were regenerated from the epidermis. In addition, commercial striped *Saintpaulia* cultivars interestingly have petals with a blue and pink pattern. This color pattern is similar to "Kaname" and is due to their easy growing. The mutation of *SiF3*′*5*′*H* was not supposed to affect cell division activity. On the other hand, type such as "Concord" and "Monique" which have colorless layers are difficult to grow because their growth vigor is low (Table [4](#T4){ref-type="table"}, Figure [8](#F8){ref-type="fig"}). Thus, this type of cultivars is very rare in horticultural cultivars. This slow vigor seems to due to differences in the stop position of anthocyanin biosynthetic genes. Mutations in genes on the anthocyanin synthesis pathway generally do not affect the growth of the plant (Holton and Cornish, [@B8]). However, in *Saintpaulia*, the mutation of anthocyanin biosynthesis genes, at least *SiWDR* or *SiF3H* mutations, will contribute to a low vigor of cell divisions.
Why were all regenerated shoots with a periclinal chimeral structure true-to-type?
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In *Saintpaulia*, the trait of anthocyanin biosynthesis under the L2 layer affects the coloring of the L1 layer (Matsuda et al., [@B20]), so the white-colored mutant of the L2 layer should appear as a pale stripe in the center of a petal. However, in "Concord" and "Monique," we could not obtain L2-mutated periclinal chimeral plants. When a meristem is composed of different cells and types of cells have a different vigor, vigorous cells will dominate and the chimeral structure will disappear. In fact, we could find some mericlinal or sectorial chimera in "Kaname" but could not find any these types of chimeras in "Concord" and "Monique." Sato et al. ([@B29]) cultured the leaf lamina of *Saintpaulia* "Thamires" which has blue splotches on pink petals and obtained various mutants in the regenerants. The cause of the blue splotches is spontaneous transposition of the *h*AT superfamily transposoable element (TE) from the *SiF3*′*5*′*H* promoter, and the blue color was determined to be a malvidin derivative and the pink pigment a pelargonidin derivative. During shoot regeneration, TE was transposed from the promoter region and many monochromatic blue mutants and periclinal mutants were obtained. Some of the periclinal chimera was L1 pink and L2 blue, which is the same pattern as "Kaname," and the others were L1 blue and L2 pink which is the opposite color pattern to "Kaname." So, this means that a periclinal chimera structure with a mutated *SiF3*′*5*′*H* L2 is possible. If the vigorous L1 covered the non-vigorous inner layer, it would be difficult for this type of periclinal chimera to maintain its structure. We often find some leaf variegated plants whose L1 are an unvigorous albino genotype, and which have been maintained for many years in vegetative propagation. This suggests that when the vigorous L2 is covered by weak L1, it makes the chimeral meristem structure stable. We can suppose that L1 cells are much vigorous than L2 cells. L1 cells will invade into the L2 and break the chimera structure. So, if the cells with a different vigor compose a SAM, the low-vigor cells will distribute at the outer cell layer, L1.
Two possibilities can be considered in the process of shoot regeneration of a periclinal chimera. One is a case where the L2 layer develops SAMs that include cells of the L1 layer, and the other is a case where a mosaic SAM with L1 and L2 cells occur and more stable periclinal structured SAMs are screened (Figure [9B](#F9){ref-type="fig"}). Here, we can observe shoot regeneration from L2 cells pushing up L1 cells, however, the latter possibility cannot be abandoned based on the results from this study.
In conclusion, we propose that the striped *Saintpaulia* cultivars, whose patterns are derived from a periclinal chimera structure, can be divided into two types. One type is cultivars whose regenerated shoots are derived from the epidermal layer, such as "Kaname," whose epidermis undergoes active cell division during tissue culturing. Another type is cultivars that have a relatively high percentage of regenerated adventitious shoots that strictly adhere to their mothers\' original chimeral structures, such as "Concord" and "Monique," whose inner cells but not epidermal cells undergo active cell division during tissue culturing. The latter type of cultivars may be recognized by comparing growth characteristics of separated epidermis-derived plants and inner-derived plants, which show vigorous and less vigorous growth, respectively.
Author contributions {#s5}
====================
TN contributed to data collection, data analysis, and writing the draft manuscript; SY, SO, AD, and MD contributed to data analysis, data interpretation, drafting the work, and final approval of the version; KH and FT contributed to data collection, data analysis, data interpretation, drafting the work, and final approval of the version; MH contributed to the conception or design of the work, data analysis, data interpretation, writing the draft manuscript, and final approval of the version.
Conflict of interest statement
------------------------------
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We must say special thanks to Dr. Yasuo Yasui and Dr. Masahiro Osakabe at Kyoto University for their support on sequence data collections in this study.
**Funding.** This study was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 15K14651.
Supplementary material {#s6}
======================
The Supplementary Material for this article can be found online at: <https://www.frontiersin.org/articles/10.3389/fpls.2017.01749/full#supplementary-material>
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[^1]: Edited by: Jianjun Chen, University of Florida, United States
[^2]: Reviewed by: Yu-Chung Chiang, National Sun Yat-sen University, Taiwan; Elena Corredoira, Consejo Superior de Investigaciones Científicas (CSIC), Spain
[^3]: This article was submitted to Crop Science and Horticulture, a section of the journal Frontiers in Plant Science
|
Q:
Standard warning triangle available in Cocoa for Mac OS 10.7
does anyone know if and where the standard "Warning Triangle" to display problems is available to use in Cocoa-applications?
I mean the symbol that Mail.app displays in the sidebar when there is trouble with a mail-account.
If it is in the documentation I haven't found it yet.
Thank you
A:
NSImageNameCaution will give you the system image with the standard "triangle containing an exclamation mark".
|
everything you need to know
Although the agreement lifted international sanctions, the US continues to impose unilateral measures that have scared off investors. Washington cites Iran’s missile programme, its human rights record and support for terrorism.
Some experts say Iranian establishment figures may want to keep Rouhani in power to avoid being cast back into isolation.
“With the deal in jeopardy, the system will be in vital need of Rouhani’s team of smiling diplomats and economic technocrats to shift the blame to the US and keep Iran’s economy afloat,” said Iran analyst Ali Vaez of the International Crisis Group.
Who is going to win?
“Raisi has a good chance to win. But still the result depends on the leader Khamenei’s decision,” said a former senior official, who declined to be identified.
So far in public Khamenei has called only for a high turnout, saying Iran’s enemies have sought to use the elections to “infiltrate” its power structure, and a high turnout would prove the system’s legitimacy.
A high turnout could also boost the chances of Rouhani, who was swept to power in 2013 on promises to reduce Iran’s international isolation and grant more freedoms at home. The biggest threat to his re-election is apathy from disappointed voters who feel he did not deliver improvements they hoped for.
“The result depends on whether the economic problems will prevail over freedom issues,” said an official close to Rouhani. “A low turnout can harm Rouhani.” |
var _ = require('lodash');
var ProcessEngine = require('./src/process-engine.js');
var ProcessDefinition = require('./src/process-definition.js');
var Diagram = require('./src/diagram-model.js');
var CommonTask = require('./src/common-task.js');
var HumanTask = require('./src/human-task.js');
var ProcessInstance = require('./src/process-instance.js');
_.extend(ProcessEngine.prototype, ProcessInstance.API);
ProcessEngine.InstanceStatus = ProcessInstance.Instance.STATUS;
ProcessEngine.HumanTaskServiceStatus = HumanTask.Service.STATUS;
_.extend(ProcessEngine.prototype, ProcessDefinition.API);
_.extend(ProcessEngine.prototype, Diagram.API);
ProcessEngine.create = function (options_) {
var options = options_ || {};
var processEngine = new ProcessEngine(options);
processEngine.processBuilder = ProcessDefinition.processBuilder;
processEngine.registerTaskType('service-task', CommonTask.ServiceTask, CommonTask.ServiceNode);
processEngine.registerTaskType('decision', CommonTask.Decision, CommonTask.DecisionNode);
processEngine.registerTaskType('human-task', HumanTask.Task, HumanTask.Node);
processEngine.humanTaskService = new HumanTask.Service(processEngine);
return processEngine;
};
// console.log(ProcessEngine);
// console.log(ProcessEngine.prototype);
// console.log(ProcessEngine.create());
module.exports = ProcessEngine; |
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