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What is tungsten carbide?
Tungsten carbide (WC) is a generally utilized building material which is typically arranged at high temperature. Another component for integrating nanoscaled WC at ultralow temperature has been found. This revelation opens a novel course to orchestrate significant WC and different carbides at an expense proficient way. The novel development system is taking into account a particle trade sap as carbon source to mainly grapple the W and Fe species. As a middle of the road, FeWO4 can be shaped at lower temperature, which can be specifically changed over into WC alongside the carbonization of sap. There are many variations of tungsten carbide such as tungsten carbide drum, tungsten carbide bullet and ball. The measure of WC can be under 2 nm. The impetus made with Pt nanoparticles bolstered on nanosized WC-GC (WC-graphitized carbon) shows improved electrocatalytic action for oxygen decrease response. The outcome likewise demonstrates that the Pt nanoparticles kept on WC-GC are commanded by Pt (111) plane and demonstrates a mass action of 257.7 mA mg−1Pt@0.9
Applications of Tungsten Carbide
Tungsten carbide (WC) is an interstitial compound of C iotas filling into W precious stone, which has high quality and unbending nature as covalent compound, high dissolving point as ionic gem and electromagnetism as move metal. WC has wide applications in national safeguard, substance commercial enterprises, electronic businesses, mechanical apparatuses and surface coatings1, 2, 3, 4, 5, 6. WC has the qualities of high hardness, great wear-resistance, great crack resistance and high temperature quality.
Those properties make it a thought covering material for stoneware, china product, and etch instrument. In any case, because of the high softening purpose of WC (ordinarily as high as 2800°C), it is barely to frame horniness combination through sintering procedure. As a rule, Co metal was utilized to tie WC particles to enhance its bowing resistance, yet Co lessens the decay resistance, hardness and wear-resistance of the alloy1, 2, which created the advancement of word related asthma to a certain degree7. Therefore, the systems to sinter WC by release of ion3, microwave4, high recurrence inducement5 and high temperature insostatic pressing6 were received, yet the high handling expense confined their applications in modern generation scale.
How to prepare nanoparticles with cost efficient method
To get ready WC nanoparticles with expense effective strategy, lower vitality consumption, and controllable molecule size is a basic test for wide use of WC in commercial ventures. The conventional union strategy for WC includes warming the completely blended WO3 (or W metal) and carbon powder at 1000–1600°C.
Be that as it may, the resultant WC particles are by and large enormous in size and lower in particular surface territory. Various routines have been produced to acquire nanoscale WC particles, a sample, under 10 nm WC particles could be made by ball processing. However this strategy is time and vitality expending.
Additionally, the items created by ball processing are inclined to defilement in processing pot. Shen et al. utilized an enhanced microwave warming strategy, the measure of the WC particles could be controlled by altering the warming and unwinding time44. Lee et al. traded the oxygen in WO3 with cation of zeolite halogenate, and after that lessened the intermediates to WC by CO at 550–750°C45. Because of the trouble of trading the particles in strong materials, the item all in all comprise of bigger WC particles with up to a few hundred nanometers in size. By the by, these systems stay pretty much the accompanying burdens: complex methods, long time, high temperatures and high energy utilization. | <urn:uuid:4f28d499-4814-4331-a3b2-11462ec4fe01> | 2.96875 | 810 | Personal Blog | Science & Tech. | 30.898895 | 95,635,298 |
THEMIS Image of the Day, August 9, 2017. This image shows the central part of the dune field on the floor of Russell Crater, including the smaller dunes and the massive ridge of sand.
Russell Crater is located in Noachis Terra. A spectacular dune ridge and other dune forms on the crater floor have caused extensive imaging by scientists as they seek to understand these dunes.
NASA’s Mars Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69,000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions.
Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all.
For the next several months the Image of the Day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images!
More THEMIS Images of the Day by geological topic. | <urn:uuid:e2b6bacb-b91b-487f-b618-b24641375e11> | 3.203125 | 284 | News (Org.) | Science & Tech. | 44.022121 | 95,635,308 |
Visual Basic for Applications Reference
Initializes the random-number generator.
Randomize uses number to initialize the Rnd function's random-number generator, giving it a new seed value. If you omit number, the value returned by the system timer is used as the new seed value.
If Randomize is not used, the Rnd function (with no arguments) uses the same number as a seed the first time it is called, and thereafter uses the last generated number as a seed value.
*Note* To repeat sequences of random numbers, call Rnd with a negative argument immediately before using Randomize with a numeric argument. Using Randomize with the same value for number does not repeat the previous sequence.
Security Note Because the Random statement and the Rnd function start with a seed value and generate numbers that fall within a finite range, the results may be predictable by someone who knows the algorithm used to generate them. Consequently, the Random statement and the Rnd function should not be used to generate random numbers for use in cryptography. | <urn:uuid:5bf97b90-06a1-48cd-9a73-c722e0d69a49> | 3.421875 | 211 | Documentation | Software Dev. | 31.868446 | 95,635,311 |
- Diamagnetic, Paramagnetic, and Ferromagnetic Substances, with Examples
- Dia and Para Magnetic Material
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- Material Magnetism Characteristics
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- Diamagnetism, Paramagnetism, Ferromagnetism
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- Ferromagnetism on the basis of domain theory
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- Matter and Magnetism part 22 (Paramagnetic and Ferromagnetic Substance)
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- Matter and Magnetism part 21 (Dimagnetic Substance)
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Out of the two magnetic materials, 'A' has relative permeability slightly greater than unity while 'B' has less than unity. Identify the nature of the materials 'A' and 'B'. Will their susceptibilities be positive or negative?
Show diagrammatically the behaviour of magnetic field lines in the presence of (i) paramagnetic and (ii) diamagnetic substances. How does one explain this distinguishing feature?
In what way is the behaviour of a diamagnetic material different from that of a paramagnetic, when kept in an external magnetic field? | <urn:uuid:6974a33b-85e0-4d03-8dc9-3e4c4573fa56> | 3.359375 | 277 | Content Listing | Science & Tech. | 4.223333 | 95,635,328 |
Java is an object-oriented language that adapts itself to the real-world problem being solved as opposed to a procedural language that adapts the problem to itself. In this chapter, we explore some features of Java that make it possible to adapt the programs to the problem rather than the other way around. The real world and its problems are composed of objects such as a room, a classroom, a cow, and the cow’s tail. The objects in the real world also have relationships among themselves; for example, the classroom is a room, and the cow has a tail. You will see in this chapter how Java supports these object-oriented relationships.
KeywordsObject Reference Target Type Return Type Public Class Identical List
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When our solar system was young, its biggest babies--Jupiter and Saturn--threw tantrums by the trillion. The huge planets hurled ice-covered rocky bodies from the inner solar system far past the orbit of Pluto. Some of those bodies revisit their old neighborhood as "long period" comets, which have been called the Rosetta Stone of the solar system because their pristine composition holds the key to understanding how Earth and similar planets formed. Astrophysicists from the University of Minnesota and the Spitzer Science Center (California Institute of Technology) will present sharp pictures of comets and their dust trails, as well as data on comets chemical composition, taken during the Spitzer Space Telescopes first year of operation during a poster session and press conference Tuesday, Jan. 11, at the American Astronomical Society meeting in San Diego.
Unlike the Hubble Space Telescope, Spitzer does not oribt Earth; instead, it travels behind the Earth in the same orbital path. It operates at infrared wavelengths, which enables it to see objects and material too cold to emit visible light. This is possible because even cold objects radiate heat to their surroundings as long as the surroundings are even colder. That heat is given off as infrared radiation; the cooler the object, the longer the wavelength of infrared light it emits.
The astrophysicists who will present the studies are Robert Gehrz, a University of Minnesota astronomy professor and key member of the team that focused Spitzer in orbit; Charles "Chick" Woodward and Michael Kelley, astronomy professor and graduate student, respectively, at the university; and William T. Reach of the Spitzer Science Center at the California Institute of Technology.
Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
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20.07.2018 | Power and Electrical Engineering
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20.07.2018 | Materials Sciences | <urn:uuid:31c041c3-1167-4946-94d5-0bdbd4fa3f23> | 3.921875 | 915 | Content Listing | Science & Tech. | 36.001053 | 95,635,355 |
Tracking wildlife migration has been historically difficult in the rugged terrain of Alaska. Researchers primarily rely on either surveys or GPS tracking to understand bird migration patterns. Both methods are expensive, either in terms of time or money. And the trackers are often too large or heavy.
One way to sidestep these common issues is to record audio from frequently used nesting grounds. Using birdsong allows researchers to unobtrusively study the animals, although there’s a downside. Each day produces a flood of audio recordings from multiple microphones placed around nesting grounds. It takes trained listeners endless hours to search the noisy soundscape for birdsong.
In a recently published paper in the journal Science Advances, U.S. researchers explain how they got around these tracking troubles. Columbia University ecologist Ruth Oliver and her fellow collaborators replaced the human ears with machine learning algorithms to listen to birdsong.
Oliver told VOA News, “Arrival times of migratory song birds is really important for their reproductive success. And obviously sending people to the Arctic to do field work is very expensive and takes a lot of time” — hence, the scientists’ interest in creating an automated method for tracking bird species.
Oliver and her colleagues focused on migratory songbirds who fly to northern Alaska during their mating season. These birds tend to chirp more frequently as soon as they reach the breeding grounds to attract a mate. Spring is short in Alaska and the birds must breed and hatch their clutch before winter.
The team of researchers recorded the springtime soundscape of northern Alaska for five sequential years. They placed microphones at four sites in the foothills of the Brooks Range, which recorded 1,200 audio hours.
However, Oliver admitted the recordings weren’t always perfect. “There’s a lot of other noise in these recordings” Oliver said. “Even in May in northern Alaska there’s lots of wind, lots of rain, and all of that is confounding when you’re listening to birds.”
The scientists fed hours of audio into two types of machine learning algorithms — one that used human expertise to help train it and one that relied solely on the collected audio. Both algorithms were based on the same model that’s used by applications like Siri and Alexa.
Oliver told VOA that in creating the human-supervised algorithm, she “wrote a little program to randomly sample about 1 percent of the data set” and then listened to 4-second clips. She scored these clips as either containing or not containing songbird vocalizations and then fed this information into the program.
Both algorithms were fairly accurate at estimating when the avian commuters arrived in the foothills. The models showed the importance of snowmelt for the arrival of the traveling birds. The human-trained model was slightly better at recognizing the relationship between weather conditions and bird calls, although neither model specifically tracked individual species.
This technique has great potential according to Emily Jo Williams, vice president of migratory birds and habitat at the American Bird Conservancy, “This kind of technique that allows you to survey populations in those remote areas is really exciting and could allow us to even discover new places where protection and conservation efforts are needed,” she said.
This study looked at nesting grounds near the Alaskan Arctic Refuge, which is a summer home for birds from nearly every continent. For example, the Northern Wheatear travels approximately 21,000 kilometers (13,000 miles) from Africa to summer in the refuge.
Williams told VOA, “We know from some research that some birds’ ranges have actually changed, and they’ve moved in response to what we think is a warming climate.” She went on to explain that “the timing of that migration has evolved over eons, and in large part it’s relative to what food sources are available over a particular time, what weather patterns are or aren’t favorable. So you could end up with bird migration out of sync with insect hatches or the phenology of plants that birds have a relationship to.”
Tools like the algorithm created in this study could be used to track how migratory patterns of many species may shift in response to climate change. Using machine learning is a new way to follow these shifting patterns in birds, insects and other animals. (VOA)Click here for reuse options!
Copyright 2018 NewsGram | <urn:uuid:cf112a29-4f35-4e80-b9af-69b7d6a9a6ba> | 3.640625 | 912 | News Article | Science & Tech. | 40.560557 | 95,635,358 |
Climate Change And Environment
#Climate_change has created enormous amount of impacts on the earth especially in case of environment the issues arising are intense heat waves, ascending sea levels, variations in precipitation which gave way for flooding and droughts, extreme hurricanes and deteriorated air condition that has impact both directly and indirectly to the physical and physiological health. In order to reduce all this risks Mitigation and Adaptation is needed. #Environmental consequences is the most standout impact when compared to others.
- Ecological exploitation
To know more visit us @ #Climate_Change 2018 scheduled during October 15-16, 2018 at Rome , Italy. | <urn:uuid:250f0185-a728-43e8-9f09-37076850679c> | 2.609375 | 126 | News (Org.) | Science & Tech. | 9.950114 | 95,635,365 |
U.N. climate experts reportedly fear global warming might cause the Earth's temperature to rise far higher than now predicted.
The Geneva-based Intergovernmental Panel on Climate Change says scientists are unable to reliably predict how quickly the atmosphere will warm as carbon dioxide levels increase, The Guardian reported Tuesday.
The report will be presented to national governments in April. IPCC members meet in June to produce a final version of the report that's to be made public next year.
The IPCC previously estimated a doubling of carbon dioxide would increase average global temperature by between 2.7 degrees and 8.1 degrees Fahrenheit. Since then, some computer models have predicted increases as high as 20 F.
Sources say the draft now assumes a doubling of carbon dioxide would result in a temperature rise between at least 3.6 F and 8.1 F, with greater increases possible.
Dave Stainforth, an Oxford University climate modeler, told The Guardian: "This is something of a hot topic, but it comes down to what you think is a small chance. Even if there's just a half percent chance of destruction of society, I would class that as a very big risk."
Copyright 2006 by United Press International
Explore further: Stronger west winds blow ill wind for climate change | <urn:uuid:4961e58a-a48b-4d3c-adda-cd8714978a7b> | 3.125 | 255 | News Article | Science & Tech. | 51.601098 | 95,635,394 |
A new European meteorological satellite soared into space today, Sept. 17, with five environmental instruments aboard that were developed by the Polar Operational Environmental Satellites (POES) Project at NASA's Goddard Space Flight Center in Greenbelt, Md. These instruments were developed under a reimbursable agreement with the National Oceanic and Atmospheric Administration (NOAA).
"This launch is exciting not only because of the engineering accomplishment of building and launching complex instruments and satellites, but equally rewarding for the multinational cooperation and teamwork that got us there," remarked Karen Halterman, POES Project manager at Goddard.
The European Meteorological Operational (MetOp)-B spacecraft was aboard a Soyuz launch vehicle that launched from Baikonur Cosmodrome in Kazakhstan. MetOp-B is the second of three European Space Agency (ESA) and European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) weather satellites.
The five NASA-developed, NOAA-provided instruments, include: the Advanced Microwave Sounding Unit (AMSU)-A1 and AMSU-A2; the Advanced Very High Resolution Radiometer (AVHRR); the High Resolution Infrared Radiation Sounder (HIRS); and the Space Environment Monitor (SEM).
The Goddard-developed instruments will gather data that includes remotely sensed vertical profiles of atmospheric temperature and moisture, and visible and infrared imagery of cloud cover and surface conditions such as vegetation, snow and ice. These are input into short-, medium- and long-range weather forecast models by the National Weather Service. The data are also used for climate models and to improve understanding of Earth's atmospheric and ocean processes. Measurements of charged particles in situ are used to determine levels of aurora activity and to monitor the intensities of energetic particles in Earth’s radiation belts and during solar storms. NOAA provides the data from these instruments to users around the world.
Goddard's POES Project developed the same instruments for the previous NOAA environmental satellites, NOAA-15 through NOAA-19, and for MetOp-A, which was launched in 2006. These instruments have provided reliable global environmental measurements of Earth continuously since 1998.
The AMSU–A1 and AMSU-A2 instruments are cross-track scanning total power radiometers that measure scene radiance (temperature) in the microwave spectrum. The data from these instruments is used in conjunction with the HIRS to calculate the global atmospheric temperature and humidity profiles from Earth's surface to the upper stratosphere. The data are used to provide precipitation and surface measurements including snow cover, sea ice concentration, and soil moisture. AMSU data is even used to characterize the internal structure of hurricanes. The AMSU-A1 and AMSU-A2 were designed and manufactured by Aerojet (now Northrop Grumman Electronics Systems) in Azusa, Calif.
The AVHRR is a six-channel imaging radiometer that detects energy in the visible, near infrared and infrared portions of the electromagnetic spectrum. The instrument measures reflected solar (visible and near-IR) energy and radiated thermal energy from land, sea, clouds and the intervening atmosphere. Data from the AVHRR are used to produce numerous science products including imagery, cloud cover, snow and ice cover, sea surface temperatures, vegetation, smoke plumes, volcanic ash, aerosols and absorbed incoming solar radiation to Earth and outgoing radiation from Earth. It was developed and manufactured by ITT (now Exelis) in Ft. Wayne, Ind.
The HIRS was also developed and manufactured by ITT (now Exelis). The HIRS measures the atmosphere in 20 spectral regions and its data are used together with data from the AMSU-A1 and AMSU-A2 to produce global atmospheric temperature and humidity profiles. The HIRS data are also used to determine ocean surface temperatures, total atmospheric ozone levels, precipitable water, cloud height and coverage, surface radiance and outgoing long-wave radiation.
The Space Environment Monitor was developed and manufactured by Panametrics in Waltham, Mass., and is now maintained by ATC in Chelmsford, Mass. It measures the charged particle environment at satellite altitude including the intensities of energetic particles in Earth's radiation belts and the solar wind. The SEM contributes to space weather forecasting by providing warnings of solar wind occurrences that may impair long-range communications, cause damage to satellite circuits and solar panels, or cause changes in drag and magnetic torque on satellites.
"These crucial instruments will be used for weather forecasting and to help us all gain a better understanding of the Earth's systems," stated Gene Martin, POES Project instrument manager. "We have received outstanding support and dedication from our staff and the instrument contractors Northrop Grumman Electronics Systems, Exelis and Assurance Technology Corporation."
NOAA and EUMETSAT are partners in the European Initial Joint Polar System (IJPS) with the agreement to fly their partner’s sensors on their own polar satellites and to exchange data from the POES and MetOp satellites. The MetOp satellites carry the sensors in the morning orbit, and NOAA’s polar-orbiting environmental satellites, which are the U.S. contribution to the IJPS agreement, circle Earth in the afternoon orbit. NASA's POES project manages the development, testing and integration of the five U.S. instruments for the MetOp satellites under a reimbursable agreement with NOAA.
Goddard worked closely with NOAA and a sizeable international team throughout the multiyear effort to prepare for the MetOp-B launch. The Goddard instrument team delivered the instruments to Astrium in Friedrichshafen, Germany, and supported their integration into the MetOp-B Payload Module. Thermal vacuum testing of the Payload Module was conducted at ESA's Technical Center in Noordwijk, Holland. The Payload Module was integrated with the spacecraft bus in Toulouse, France. The spacecraft arrived in Baikonur, Kazakhstan, in March 2012 and was readied for launch. | <urn:uuid:52b634ff-3516-4109-b775-6123e4fa75a1> | 3.421875 | 1,240 | News (Org.) | Science & Tech. | 17.987367 | 95,635,416 |
Queen traits and colony size of four bumblebee species of China
- 60 Downloads
Bumblebee pollination efficiency is significantly affected by colony size, which differs among different bumblebee species. Bumblebee colonies are initiated by a single queen; thus queen traits have an important influence on colony development. To make better use of native bumblebee species and select bumblebee species for commercial rearing, queens from four bumblebee species in China, Bombus terrestris, B. lantschouensis, B. patagiatus and B. ignitus, were reared and studied to determine whether differences in queen traits and colony size occur at the interspecific level. In our study, the four bumblebee species differed significantly in colony size, queen body length, spermatheca size and sperm quantity. The queens of the four species mated only once. Among these four bumblebee species, the species with more sperm in the queen’s spermatheca usually exhibited a larger colony size. The quantity of sperm in the queen’s spermatheca might serve as an indicator for selecting bumblebee species with commercial rearing potential. However, our study involved only four bumblebee species; more bumblebee species are needed to confirm the correlation between queen sperm quantity and colony size.
KeywordsBombus Native species Rearing characteristics Resource selection
Thanks to Shiwen Zhang, Aiping Han, Zhengying Miao, and Fangzhi Han for the wild queen collection work; to Wenbo Zhang for the bumblebee rearing work; to Paul H. Williams for identifying the bumblebee species; to reviewers for their comments and hard work; and to Cheng Sun and Yanjie Liu for their helpful discussions.
JA conceived the research and designed the paper. HZ performed the research, analysed the data and wrote the paper. ZZ performed the research and analysed the data along with HZ. JH performed the research and improved the paper. XY and GD performed the research.
This work was supported by the Agricultural Science and Technology Innovation Programme (CAAS-ASTIP-2015-IAR) and the Natural Science Foundation of China (31672500, U1603108).
Compliance with ethical standards
Conflict of interest
We have no competing interests.
- Baer B (2016) Proximate and ultimate consequences of polyandry in ants (Hymenoptera: Formicidae). Myrmecol News 22:1–9Google Scholar
- Hingston AB, Marsden-Smedley J, Driscoll DA, Corbett S, Fenton J, Anderson R, Plowman C, Mowling F, Jenkin M, Matsui K, Bonham KJ, Ilowski M, Mcquillan PB, Yaxley B, Reid T, Storey D, Poole L, Mallick SA, Fitzgerald N, Kirkpatrick JB, Febey J, Harwood AG, Michaels KF, Russell MJ, Black PG, Emmerson L, Visoiu M, Morgan J, Breen S, Gates S, Bantich MN, Desmarchelier JM (2002) Extent of invasion of Tasmanian native vegetation by the exotic bumblebee Bombus terrestris (Apoidea: Apidae). Aust Ecol 27:162–172CrossRefGoogle Scholar
- Matsumura C, Yokoyama J, Washitani I (2004) Invasion status and potential ecological impacts of an invasive alien bumblebee. Bombus terrestris L. (Hymenoptera: Apidae) naturalized in southern Hokkaido, Japan. Glob Environ Res 1:51–66Google Scholar | <urn:uuid:0e3c3d23-b352-42dd-b2f5-2ac11fd41a09> | 3.140625 | 776 | Academic Writing | Science & Tech. | 37.488068 | 95,635,419 |
They investigated how nerve signals are suppressed inside the so-called entorhinal cortex. According to the researchers, this neuronal inhibition leads nerve cells to synchronize their activity. The results of this study are now published in Neuron.
A microscopic view of the entorhinal cortex. The bright spots are the bodies of neurons.
Source: DZNE/Charité – Universitätsmedizin Berlin, Beed/Schmitz
The entorhinal cortex is a link between the brain’s memory centre, the hippocampus, and the other areas of the brain. It is, however, more than an interface that only transfers nervous impulses. The entorhinal cortex also has an independent role in learning and thinking processes. This is particularly applicable for spatial navigation. “We know precious little about how this happens," says Prof. Dietmar Schmitz, a researcher at the Cluster of Excellence NeuroCure at the Charité – Universitätsmedizin Berlin and Site Speaker for the DZNE in Berlin. “This is why we are investigating in animal models how the nerve cells within the entorhinal cortex are connected with each other.“
Signals wander inside the brain as electrical impulses from nerve cell to nerve cell. In general, signals are not merely forwarded. Rather, operation of the brain critically depends on the fact that the nerve impulses in some situations are activated and in other cases suppressed. A correct balance between suppression and excitation is decisive for all brain processes. “Until now research has mainly concentrated on signal excitation within the entorhinal cortex. This is why we looked into inhibition and detected a gradient inside the entorhinal cortex,” explains Dr. Prateep Beed, lead author of the study. "This means that nerve signals are not suppressed equally. The blockage of the nerve signals is weaker in certain parts of the entorhinal cortex and stronger in others. The inhibition has, so to speak, a spatial profile.”
When the brain is busy, nerve cells often coordinate their operation. In an electroencephalogram (EEG) – a recording of the brain’s electrical activity – the synchronous rhythm of the nerve cells manifests as a periodic pattern. "It is a moot question as to how nerve cells synchronize their behavior and how they bring about such rhythms," says Beed. As he explains, it is also unclear whether these oscillations are only just a side effect or whether they trigger other phenomena. "But it has been demonstrated that neuronal oscillations accompany learning processes and even happen during sleep. They are a typical feature of the brain's activity," describes the scientist. "In our opinion, the inhibitory gradient, which we detected, plays an important role in creating the synchronous rhythm of the nerve cells and the related oscillations.”
In the case of Alzheimer’s, the entorhinal cortex is among the regions of the brain that are the first to be affected. “In recent times, studies related to this brain structure have increased. Here, already in the early stages of Alzheimer's, one finds the protein deposits that are typical of this disease,” explains Schmitz, who headed the research. “It is also known that patients affected by Alzheimer’s have a striking EEG. Our studies help us to understand how the nerve cells in the entorhinal cortex operate and how electrical activities might get interrupted in this area of the brain.”Original publication
Prateep Beed, Anja Gundlfinger et al., Neuron, DOI: 10.1016/j.neuron.2013.06.038Contact
Daniel Bayer | idw
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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Fabio H. Ribeiro
Oxidation reactions are of prime importance at an industrial level and correspond to a huge market. Oxidation reactions are widely practiced in industry and are thoroughly studied in academic and industrial laboratories. Achievements in oxidation process resulted in the development of many new selective oxidation processes. Environmental protection also relies mainly on oxidation reactions. Remarkable results obtained in this field contributed to promote the social image of chemistry which gradually changes from being the enemy of nature to becoming its friend and savior. This study dealt with two aspects regarding oxidation process. The first aspect represented an experimental study for the partial oxidation of benzene to phenol using Pd membrane in the gaseous phase. The second part was a theoretical study for some of the advanced oxidation process (AOPs) which are applied for contaminant destructions in polluted waters. Niwa and coworkers reported a one step catalytic process to convert benzene to phenol using Pd membrane. According to their work, this technique will produce a higher yield than current cumene and nitrous oxide based industrial routes to phenol. A similar system to produce phenol from benzene in one step was studied in this work. Results at low conversion of benzene to phenol were obtained with a different selectivity from the reported work. High conversion to phenol was not obtained using the same arrangement as the reported one. High conversion to phenol was obtained using a scheme different from the one reported by Niwa et al1. It was found that producing phenol from benzene is not related to Pd-membrane since phenol was produced by passing all reactants over a Pd catalyst. Within the studied experimental conditions, formation of phenol was related to Pd catalyst since Pt catalyst was not capable of activating benzene to produce phenol. Other evidence was the result of a blank experiment, where no catalyst was used. From this experiment no phenol was produced. A kinetic model for the advanced oxidation process using ultraviolet light and hydrogen peroxide (UV/H2O2) in a completely mixed batch reactor has been tested for the destruction of humic acid in aqueous solutions. Known elementary chemical reactions with the corresponding rate constants were taken from the literature and used in this model. Photochemical reaction parameters of hydrogen peroxide and humic acid were also taken from the literature. Humic acid was assumed to be mainly destroyed by direct photolysis and radicals. The rate constant for the HA- reaction was optimized from range of values in the literature. Other fitted parameters were the rate constant of direct photolysis of hydrogen peroxide and humic acid. A series of reactions were proposed for formation of organic byproducts of humic acid destruction by direct photolysis and radicals. The corresponding rate constants were optimized based on the best fit within the range of available published data. This model doesn't assume the net formation of free radicals species is zero. The model was verified by predicting the degradation of HA and H2O2 for experimental data taken from the literature. The kinetic model predicted the effect of initial HA and H2O2 concentration on the process performance regarding the residual fraction of hydrogen peroxide and nonpurgeable dissolved organic carbon (NPDOC). The kinetic model was used to study the effect of the presence of carbonate/bicarbonate on the rate of degradation of NPDOC using hydrogen peroxide and UV (H2O2/UV) oxidation. Experimental data taken from literature were used to test the kinetic model in the presence of carbonate/bicarbonate at different concentrations. The kinetic model was able to describe the trend of the experimental data. The kinetic model simulations, along with the experimental data for the conditions in this work, showed a retardation effect on the rate of degradation of NPDOC due to the presence of bicarbonate and carbonate. This effect was attributed to the scavenging of the hydroxyl radicals by carbonate and bicarbonate. A kinetic model for the degradation of methyl tert-butyl ether (MTBE) in a batch reactor applying Fenton's reagent (FeII/ H2O2) and Fenton-like reagent (Feo/ H2O2) in aqueous solutions was proposed. All of the rate and equilibrium constants for hydrogen peroxide chemistry in aqueous solutions were taken from the literature. Rate and equilibrium constants for ferric and ferrous ions reactions in this model were taken from the reported values in the literature, except for the rate constant for the reaction of ferric ions with hydrogen peroxide where it was fitted within the range that was reported in the literature. Rate constant for iron dissolution was also a fitted parameter. The mechanism of MTBE degradation by the hydroxyl radicals was proposed based on literature studies. The kinetic model was tested on available experimental data from the literature which involved the use of Fenton's reagent and Fenton-like reagent for MTBE degradation. The degradation of MTBE in Fenton's reagent work was characterized to proceed by two stages, a fast one which involved the reaction of ferrous ions with hydrogen peroxide (FeII/H2O2 stage) and another, relatively, slower stage which involved the reaction of ferric ions with hydrogen peroxide (FeIII/H2O2 stage). The experimental data of MTBE degradation in the FeII/H2O2 stage were not sufficient to validate the model, however the model predictions of MTBE degradation in the FeIII/H2O2 stage was good. Also, the model was able to predict the byproducts formation from MTBE degradation and their degradation especially methyl acetate, and tert-butyl alcohol. The effect of each proposed reaction on MTBE degradation and the byproducts formation and degradation was elucidated based on a sensitivity analysis. The kinetic model predicted the degradation of MTBE for Fenton-like reagent for the tested experimental data. Matlab (R13) was used to solve the set of ordinary nonlinear stiff differential equations that described rate of species concentrations in each advanced oxidation kinetic model. Niwa, S. et al., Science 295 (2002) 105
Worcester Polytechnic Institute
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Al Ananzeh, N. (2004). Oxidation Processes: Experimental Study and Theoretical Investigations. Retrieved from https://digitalcommons.wpi.edu/etd-dissertations/221
Fenton-like reagent, MTBE, hydroxyl radicals, Fenton’s reagent, humic acids, bicarbonate and carbonate, UV/H2O2, advanced oxidation processes, kinetic modeling, Pd membrane, phenol, benzene, Partial oxidation, Oxidation, Benzene, Phenols, Water, Pollution, Research | <urn:uuid:0a1a1ddf-3a87-4335-99e1-e00e8f4baa2d> | 2.90625 | 1,445 | Academic Writing | Science & Tech. | 22.367961 | 95,635,453 |
Gravity and Motion: Kepler/Newton. Astronomy, Chapter 2 D Taylor Edited by Mr. Baxley. Introduction. Gravity gives the Universe its structure It is a universal force that causes all objects to pull on all other objects everywhere It holds objects together
Astronomy, Chapter 2
Edited by Mr. Baxley
A ball rolling down a slope speeds up. A ball rolling up a slope slows down. A ball rolling on a flat surface rolls at a constant speed if no forces act on it.
For a mass on a string to travel in a circle, a force must act along the string to overcome inertia. Without that force, inertia makes the mass move in a straight line.
Skateboarders illustrate Newton's third law of motion. When A pushes on B an equal push is given to A by B.
Gravity produces a force of attraction between bodies. The strength of the force depends on the product of their masses, m and M, and the square of their separation, r. G is the universal gravitational constant.
a = v2/r
where v is the constant orbital speed and r is the radius of the orbit
(A) A cannon on a mountain peak fires a projectile. If the projectile is fired faster, it travels further before hitting the ground. (B) At a sufficiently high speed, the projectile travels so far that the Earth's surface curves out from under it, and the projectile is in orbit.
v = (GM/r)1/2
M = (v2r)/G
v = 2pr/T
M = (4p2r3)/(GT2)
ma = GMm/R2
where M and R are the mass and radius of the celestial object, and m is the mass of the object whose acceleration a we wish to know
g = GM/R2
Vesc = (2GM/R)1/2
where M and R are the mass and radius of the celestial object from which the mass wishes to escape
Escape velocity is the speed an object must have to overcome the gravitational force of a planet or star and not fall back.
2nd: An object’s acceleration is proportional to the net force acting upon it and inversely proportional to it’s mass.
To change it’s motion
And in this corner, weighing in at a healthy175 pounds, Albert “The Tongue” Einstein!
1917 Einstein proposes Cosmological Constant to ‘fix’ the equation (stopped U from expanding…)
1929 Hubble discovers Expansion of the Universe
1934 Big Al calls his CC “my biggest blunder”.
1998 Astronomers find evidence for CC in Dark M&E
2000 Astronomers agree Big Al was “right even when he was wrong” | <urn:uuid:f78ff0b5-c6ec-4e6a-9550-c7677e48a8b3> | 3.96875 | 589 | Truncated | Science & Tech. | 66.51387 | 95,635,473 |
Soils are important for carbon (C) storage and thus for possible mitigation of atmospheric CO₂ concentrations. In a recently published Nature Geoscience article, scientists took a closer look at the drivers of C storage in soils. The study along a 3-million-year old terrace sequence in the Californian central valley shows how soil weathering controls and influences crucial parts of terrestrial C cycling.
Quantifying soil C dynamics is crucial in the context of global change because soils play an important role in the exchange of CO₂ between land and atmosphere. Whether C is stored in soils or released back to the atmosphere is usually related to climatic factors and land management, as they control plant growth and the activity of soil microorganisms. Geochemistry, however, can be seen as the stage in which soils develop and C is cycled.
An international team of researchers led by Sebastian Doetterl from Augsburg University, Germany, and Asmeret A. Berhe from the University of California, Merced, USA shows why it is important to understand long-term mineral weathering when assessing short-term responses of soil C dynamics.
“Our models fail to accurately represent the influence that soil weathering (it is, changes in geochemistry of soils over time) can have on present and future soil carbon dynamics”, Doetterl says. The international team of researchers showed the importance of weathering processes lasting from only a couple to millions of years and how this affects plant growth, microbial communities and stabilization of soil C over time.
The scientists worked along a soil chronosequence originating from the same geologic material and developed under similar climate and vegetation cover. The youngest soils along this sequence are only a few years old, whereas the oldest, and highly weathered soils are several million years old.
“This difference in development stage of soil allowed us to investigate all kinds of changes that occur over time to the C cycle. For example, changes in vegetation types due to differing availability of nutrients, changes in microbial communities and their strategies to assess these nutrients, the capacity of minerals to stabilize C in soils and the effect that warming might have on biological processes”, Berhe adds.
The researchers demonstrate that biogeochemical alteration of the soil matrix (and not short-term warming) controls the composition of microbial communities and strategies to metabolize nutrients. More specifically, weathering first increases and then reduces nutrient availability and retention, as well as the potential of soils to stabilize C.
So how does this knowledge help to improve predictions of the future C cycle?
“The great thing about our findings is that they show biological processes that act on short time scales are closely tied to the long term changes in soils that come with weathering”, Doetterl continues.
“We hope that this understanding will instigate a better integration of weathering mechanisms into models by ecologists and biogeochemists to predict C at the global scale. If biology, that drives the C cycle, is controlled by geochemical changes in soils, we can use much simpler approaches and larger datasets of soil properties and underlying geology to create better predictions of future developments of the C cycle”, he concludes.
Doetterl S., Berhe A.A., Arnold C., Bodé S., Fiener P., Finke P., Fuchslueger L., Griepentrog M., Harden J.W., Nadeu E., Schnecker J., Six J., Trumbore S., Van Oost K., Vogel C., Boeckx P. 2018. Links among warming, carbon and microbial dynamics mediated by soil mineral weathering. Nature Geoscience, https://doi.org/10.1038/s41561-018-0168-7.
Dr. Sebastian Dötterl
University of Augsburg
Klaus P. Prem | idw - Informationsdienst Wissenschaft
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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Martian chemical complicates hunt for life’s clues
News Sep 27, 2013
A scientific paper published has been published that details the investigation of a chemical in the Martian soil that interferes with the techniques used by the Curiosity rover to test for traces of life. The chemical causes the evidence to burn away during the tests.
In search of clues to life’s presence on Mars – now or in the past – Curiosity checks Martian soil and rocks for molecules known as organic carbon compounds that are the hallmark of living organisms on Earth.
While trekking around the Rocknest sand dune in November 2012, the rover found evidence of perchlorate—a salt comprised of chlorine and oxygen. When Curiosity heats a scoop of Martian soil to test it for organic carbon, perchlorates can cause a chemical reaction that destroys organic carbon. Daniel Glavin, an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and first author on the new paper, said he now believes the troublesome perchlorates are likely prevalent throughout the Martian surface.
“The presence of perchlorates isn’t good news for some of the techniques we’re currently using with Curiosity,” said Glavin. “This may change the way we search for organics in the future on Mars.”
Curiosity mission scientists previously announced finding perchlorates last December at the 2012 Fall Meeting of the American Geophysical Union (AGU) in San Francisco. Now, in the Journal of Geophysical Research: Planets, an AGU publication, they provide much more detail about the evidence and examine its potential impact on Mars exploration. Five other papers with other findings from the Curiosity mission are publishing today in the journal Science.
Accounting for perchlorate
The Curiosity rover’s Sample Analysis on Mars (SAM) system tests soil samples by heating them in an instrument, called a pyrolysis gas chromatograph mass spectrometer, which breaks the samples down into their chemical components and determines precisely how much of each of those components is present in the sample. Any perchlorate salts in the heated sample decompose as the temperature goes above 200 degrees Celsius (392 degrees Fahrenheit) and release pure oxygen. Organic molecules in the sample exposed to this oxygen will then combust into carbon dioxide, destroying the molecular evidence of their presence. Luckily, Glavin said, some organic carbon would likely survive, either incased in more heat-resistant materials or detected before the breakdown of perchlorates.
Glavin noted that scientists can account for the destroyed organic carbon by assuming a certain baseline of perchlorate in the Martian soil. In future tests, scientists can calculate how much organic carbon burnt away with the decomposing perchlorates in order to estimate the original amount of organic material in the soil. The findings at Rocknest serve particularly well for this purpose because the site was originally chosen because it was unlikely to have any organic material.
“It will be absolutely critical as we move on to other samples to compare them to the Rocknest dune to infer the presence or absence of Martian organic material,” said Glavin.
While Curiosity findings published today in Science do not use Rocknest as a perchlorate baseline, Glavin said the next batch of papers from the Sheepbed mudstone will use them for calibration.
Glavin added that Curiosity has the potential to avoid the perchlorate problem in the future by using techniques that do not involve heating the soil to the point where perchlorates break down. The rover already carries an apparatus capable of that, which it hasn’t yet used. The system, which employs liquids in its chemical assays, is more complicated than those currently in operation, Glavin said. And, it requires additional testing before it can be used, which he expects could happen in the near future.
How do Forests Respond to Atmospheric Pollution?News
How forests respond to elevated nitrogen levels from atmospheric pollution is not always the same. While a forest is filtering nitrogen as expected, a higher percentage than previously seen is leaving the system again as the potent greenhouse gas nitrous oxide, say researchers.READ MORE | <urn:uuid:3f67b126-7ce8-4888-b21a-cc6466d4128c> | 3.375 | 858 | News Article | Science & Tech. | 26.172 | 95,635,486 |
The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/phos, photos meaning "light" and σφαῖρα/sphaira meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately 2/3. In other words, a photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths.
The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface . | <urn:uuid:6bb5d809-0160-42ea-8ad5-d9a16577d540> | 4.0625 | 197 | Knowledge Article | Science & Tech. | 43.98587 | 95,635,502 |
The search for evidence that life evolved somewhere beyond Earth, or has evolved on Earth has led to interesting research, but has yielded no signs of any extra-terrestrials. Still, if some form of life were found, people would probably react positively.
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- Blinking eye cells on a polymer chip – along with other “organs-on-chips” – offer a new way to examine the effects of drug treatments on humans, according to the panelists of a Feb. 16 news briefing at the 2018 AAAS Annual Meeting.
- Say the late 20th century defined physics and engineering, then the 21st century may do the same for biology and engineering, says AAAS President Hockfield.
- Efforts to limit access to voting, compounded by election security concerns, have created a lack of confidence in the U.S. voting system, said Myrna Perez, professor of law and director of the Brennan Center for Justice Voting Rights and Elections Project at the New York University School of Law.
- Using airborne mapping, researchers are discovering new archeological sites that show pre-Columbian Mesoamerica was “significantly more densely populated at the time of European contact” than previously thought.
- News_0215_PBHockfield_full2.jpg Susan Hockfield kicked off the 2018 AAAS Annual Meeting in Austin, Texas, fielding questions from journalists gathered for the five-day event. | Professional Images Photography A virus genetically engineered to build battery components is one example of how 21 st...
- Linda Sealy, director of the Initiative for Maximizing Student Diversity at Vanderbilt University, has been selected to receive the 2018 Lifetime Mentor Award from the American Association for the Advancement of Science.
- Keivan Stassun, the Stevenson Professor of Physics and Astronomy and senior associate dean for graduate education and research at Vanderbilt University’s College of Arts and Science, has been chosen as the winner of the 2018 AAAS Mentor Award.
- Johanna Varner, a scientist who has developed citizen science programs that empower people to participate in science, has been chosen by the American Association for the Advancement of Science to receive the 2018 Early Career Award for Public Engagement with Science.
- Pennsylvania State University professor and climate scientist Michael E. Mann has been selected to receive the 2018 AAAS Public Engagement with Science Award. | <urn:uuid:e98a5ee0-7c81-42e4-be63-a1c66c961c2c> | 2.59375 | 500 | Content Listing | Science & Tech. | 31.18011 | 95,635,623 |
Professor DUAN Haibin and his group members (LUO Qinan and YU Yaxiang) from the Science and Technology in Aircraft Control Laboratory, School of Automation Science and Electrical Engineering, Beihang University set out to tackle this problem. Through 5 years of innovative research, they investigated the trophallactic mechanism behind social insects and developed a novel trophallaxis network control method for formation flight.
Trophallactic is a new swarm search algorithm. This new mechanism is based on the trophallactic behavior of social insects, animals and birds, such as ants, bees, wasps, sheep, dogs, sparrows and swallows. Trophallaxis is the exchange of fluid by direct mouth-to-mouth contact. Animal studies revealed that trophallaxis can reinforce the exchange and sharing of information between individual animals. By imitating that behavior and considering the communication requirements of the network control system, a network control method was proposed. The method was derived from the following example. A honeybee that finds the feeder fills its nectar crop with the offered sugar solution, and if the bee meets another bee on its way, there can be trophallactic contact. The higher the metabolic rate of the bee is, the higher this consumption rate will be. The attractive aspect of the trophallaxis mechanism is the ability to incorporate information transfer as a biological process and use global information to generate an optimal control sequence at each time step.
This research project was supported in part by a grant from the National Natural Science Foundation of China. It is an important breakthrough in the recent history of formation flight. The researchers suggest that their work needs to be put into practice and examined in the formation control field and that the trophallactic mechanisms of social insects should be further studied. These efforts will have significant impact on the formation control of various (marine, ground, aeronautical, and astronautical) vehicle systems.
See the article: Duan H B, Luo Q N, Yu Y X. Trophallaxis network control approach to formation flight of multiple unmanned aerial vehicles. Sci China Tech Sci, 2013, Vol. 56 (5): 1066, http://tech.scichina.com:8082/sciEe/EN/abstract/abstract510833.shtml
Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 50 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.
Factory networks energy, buildings and production
12.07.2018 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Manipulating single atoms with an electron beam
10.07.2018 | University of Vienna
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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FANCY catching the next solar and lunar eclipses in the UK?
Here's everything you need to know about the upcoming cosmic spectacles and the differences between them...
When can the next solar eclipse be seen in the UK?
The next one we are scheduled to see in the UK will be on June 10, 2021, although it will just be a partial eclipse.
It will take place over Britain ranging from a 20 per cent eclipse in northern Scotland to a 30 per cent eclipse in South East England.
Scientists say the next “deep” partial eclipse in the UK will take place on August 12, 2026 and the next total eclipse will be in September 2090.
The last solar eclipse that was visible in the UK occurred on February 26 but was only be visible in certain areas around the world - including in South and West Africa, some of South America, the Pacific, Atlantic and Indian Ocean, and Antarctica.
There will be another one on August 21 in the US.
Experts predict the natural phenomenon will continue for the next 60 million years, until the distance between the moon and the sun will be too vast.
When will the next lunar eclipse be seen in the UK?
An eclipse occurs when the moon appears darkened as it passes into the Earth's shadow, with Earth being located between the moon and the sun.
There will be two chances to see a lunar eclipse over the next two years.
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The one occurring on January 31, 2018 wasn't visible from the UK, although other parts of the world were treated to a spectacular spectacle.
The next that is visible in the UK is on July 27, 2018 – this will be a blood moon total eclipse and will be at its maximum at 9.21pm.
This will be the 21st century's longest lunar eclipse so far, lasting almost two hours.
There will be another total lunar eclipse on January 21, 2019. | <urn:uuid:53f2b43b-6ed8-4ee9-b646-1472b886e369> | 2.6875 | 398 | Truncated | Science & Tech. | 67.215962 | 95,635,677 |
From AMS Glossary
(Redirected from Magnetic inclination)
- (Also called dip.) In terrestrial magnetism, the angle through which a freely suspended magnet would dip below the horizon in the magnetic north–south meridional plane; one of the magnetic elements.
At the aclinic line (dip equator) the inclination is zero; at either magnetic pole (dip pole) the inclination is 90°. | <urn:uuid:99794afc-9aaa-4bec-b39e-96706aa1d961> | 3.078125 | 89 | Structured Data | Science & Tech. | 28.222011 | 95,635,679 |
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Science Podcast Podcast: Polio outbreak and America's first dogs On this week’s show: A vaccine-derived polio outbreak in the Democratic Republic of the Congo leads to tough choices for public health experts, and new evidence points to Siberian origins for America’s first dogs.
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Eye of Science/Science Source GLITZY HARDWARE A new kind of human-made diamond (the clear material across the middle of this optical microscope image, measuring about 4 by 10 millimeters) laced with silicon and boron could be used to build better quantum memory devices.
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The momentous transition to multicellular life may not have been so hard after all . Latest News | Jun. 28, 2018 Wang Chi Lau/Embryology Course at the Marine Biological Laboratory
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Coral may be listed as endangered, threatened
HANAUMA BAY NATURE PRESERVE, Hawaii — Ringed rice coral appears strikingly modest for a species that's caught in the struggle over greenhouse gas emissions.
The coral is among the most abundant in Hawaii's waters and is among 82 coral species the federal government is considering listing as endangered or threatened, primarily because growing amounts of carbon in the air and oceans are putting them at risk.
The deliberations are fueling a debate about the best way to help coral, given there is not yet a global plan to reduce greenhouse gas emissions.
Environmentalists say listing the coral as an endangered species would then require federal agencies to limit actions that would result in greenhouse gases that would harm the coral habitat. They pushed the same argument when polar bears were as a threatened species in 2008.
The Obama administration says that while these species may need the special protections that the 37-year-old law affords, the law is not the venue to address greenhouse gas emissions. They say a "comprehensive strategy" developed with Congress is the better way to deal with it.
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Models created by her lab and other scientists show the world's coral reefs will suffer major declines by 2050 — just four decades from now — if humans don't cut back the amount of carbon they're pumping into the air.
"The reef will break apart," Rodgers said. "You're going to see more sensitive species of coral disappear completely. You won't see them."
The National Marine Fisheries Service began its review for the 82 species last month. Of the total, 75 are in the Pacific including the U.S. territories of American Samoa and Guam. Nine are in Hawaii.
Ringed rice coral — which sometimes has a purple hue, other times rust orange or brown — grows in small patches in the nearshore waters of Hanauma Bay, one of Hawaii's most popular nature preserves. It provides food and shelter for large numbers of fish and other marine life
It's a candidate for listing because it's only found in the Hawaiian islands. This makes the species vulnerable to being wiped out if there's a heat wave or an invasive species infiltrates its habitat.
The agency has about a year to finish the review.
In the meantime, neither the U.S. or the international community has determined how it will cut greenhouse gas emissions. Restrictions could take jobs away from coal and oil producing states, and increase costs for businesses, making them politically risky.
The U.S. promised the United Nations it would cut its greenhouse gas emissions by 17 percent by 2020. But Congress must approve this plan, something that's not guaranteed.
Earlier this month, U.S. President Barack Obama met with 14 senators on the issue, telling them he wanted comprehensive legislation that would cap greenhouse gas emissions.
The government has faced the question of how to deal with greenhouse gases threatening the habitats of vulnerable species before. In 2008, the government listed polar bears as a threatened species, saying global warming was causing sea ice, the polar bear's primary habitat, to melt.
As traditionally applied, the Endangered Species Act would prompt the government to restrict the actions of state agencies and companies receiving federal permits if their activities were to harm the bear's habitat.
This approach has worked successfully for decades, helping prevent the extinction of 98 percent of species classified as endangered.
But the Interior Department said it was "not possible" to directly link the greenhouse gas emissions from a specific project — like a power plant — to melting ice floes harming the polar bears. So the department is not seeking to restrict them.
J.B. Ruhl, a professor at Florida State University College of Law, said the same logic would apply to the coral if they're listed.
"How exactly do you get from their molecules of carbon dioxide are the ones that caused what's going on here, but not those other molecules that are coming from farms?" Ruhl said. "Or people driving in New York City? Or people using air conditioning in Tucson? There's no way to sort it out."
Rising carbon levels threaten coral many ways.
First, greenhouse gases trap energy from the sun, warming the planet. Coral is vulnerable in part because it has trouble surviving in waters just one to two degrees warmer than the hottest temperatures they experience during the summer.
When the ocean becomes too hot, the coral expel the algae they normally rely on to survive. This makes them appear "bleached."
The oceans are also absorbing some of the carbon humans are pumping into the atmosphere when they drive cars and use electricity generated by burning fossil fuels. The added carbon boosts the acidity of the ocean, making it harder for coral to grow. The acidity also weakens coral skeletons, increasing the likelihood they'll break during storms.
Scientists had been predicting the amount of carbon in the ocean would double by 2100, but they now say it could happen by 2050 or earlier.
Kassie Siegel, senior counsel at the Center for Biological Diversity, said the government should treat greenhouse gases just as it would other pollutants when it comes to protecting endangered or threatened species.
"If we keep building coal-fired power plants, we will lose coral reefs," Siegel said. "One way or another we need to look at the impacts and we need to do something about it. And the Endangered Species Act is one way to get there." | <urn:uuid:cd39c2cf-a24c-4405-936c-c401462a2709> | 3.234375 | 1,317 | News Article | Science & Tech. | 48.773184 | 95,635,688 |
Scientists in the US and Germany have found the two largest prime numbers ever calculated in a discovery which could dramatically increase the effectiveness of cryptographic systems.
The two numbers were discovered within a fortnight of each other by the Great Internet Mersenne Prime Search project, which has spent 12 years on the task.
The largest prime number, which has a whopping 12,978,189 digits, was discovered by a team from UCLA. The second, discovered by a computer user in Germany, has 11,185,272 digits.
The search for large prime numbers (those which can only be divided by themselves or one) was sponsored by the Electronic Frontier Foundation (EFF) as part of an effort to build a near-unbreakable encryption system.
"The EFF awards are about cooperation," said John Gilmore, EFF co-founder and project leader for the awards.
"Prime numbers are important in mathematics and encryption, but the real message is that many other problems can be solved by similar methods."
The UCLA team will receive a $100,000 prize from the EFF for breaking the 10,000,000 digit record. Further prizes are available, including $150,000 for the first 100,000,000 digit prime and $250,000 for the first 1,000,000,000 digit number.
Prime numbers are fundamental to cryptography systems, which take a large part of their strength from the difficulty in factoring primes. The larger the prime the more secure the encryption.
Microsoft receives a 30 per cent cut of all purchases on the Xbox digital store
Credit card thieves used Apple ID accounts to buy and sell virtual currency for Clash of Clans and Clash Royale and Marvel Contest of Champions
$5.1bn fine further evidence that the EU is anti-US, claims Trump
New cable will connect Virginia to France | <urn:uuid:a7329177-4181-4d62-bd52-87a202288051> | 2.90625 | 370 | News Article | Science & Tech. | 49.837875 | 95,635,690 |
+44 1803 865913
Invertebrate animals make up the greater part of the world's biological diversity and are present in all habitats, where they perform essential ecological functions. Their survival is fundamental to the maintenance of life as we know it. Large numbers of invertebrate species are under severe threat of extinction in Europe, or are already extinct due to the extreme transformations that European habitats have suffered due to human activities.
The European Strategy for the conservation of invertebrates, adopted by the Council of Europe (Bern Convention) in 2006, addresses the loss of invertebrate biodiversity and promotes their conservation and the services they provide in terrestrial and non-marine aquatic environments. The Strategy offers appropriate guidance to European governments, other decision-makers, land managers, scientists and teachers that have potential influence on invertebrate conservation.
Message from the Council of Europe
Guest essay by Robert M. May
'Conservation biology and the European Invertebrate Strategy'
Vision, goal and objectives
2. Inventorying, mapping and understanding invertebrate diversity
3. Preventing habitat destruction and ensuring appropriate management
4. Indicators and monitoring
5. Invasive alien species
6. Reversing the effects of intensive agriculture and forestry, and of industry and urbanisation
7. Sustainable use
8. Scientific capacity building
9. Education and public awareness
10. Co-operation and implementation
Appendix 1 - Policy and legislative frameworks for invertebrate conservation
Appendix 2 - List of acronyms
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A Program Notation
In this chapter, we introduce a notation for writing programs. It is sufficiently similar to Pascal and C to warrant only a short introduction, so we concentrate on describing the effects brought about by a program written in such a language. Let us start with an example of a Pascal program.
KeywordsGlobal Variable Procedure Call Boolean Expression Proof Obligation Reference Parameter
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Animals are cut from a cloth woven largely of collagen. This rope-like protein is the most abundant in the body, giving structure to tissues such as skin and cartilage, but to date chemists haven’t fully understood the source of collagen’s strength. A prevailing theory dictated that the molecule-a tightly wound triple helix-was braced by a scaffolding of water molecules. But research from the University of Wisconsin-Madison points to a different answer, one that not only helps explain collagen’s properties, but also might eventually expand the protein’s utility in cosmetic surgery, wound healing and perhaps even arthritis diagnosis and treatment.
Wisconsin biochemist Ronald Raines and his co-workers modified collagen so that it was incapable of forming the “water bridge” bonds previously thought to help hold the molecule together. The new form is able to endure temperatures more than 22 C higher than a model of natural collagen, probably because added fluorine atoms push the chains into a sturdy configuration, the researchers explain in the April issue of Nature.
Natural collagen is already a useful biomaterial, most famous for its starring role in the full lips and wrinkle-free faces of movie stars and models. But the protein tends to unravel in the body, so collagen injection must be repeated every few months. Raines believes that a more stable artificial collagen could be an advantage not only in plastic surgery but also in artificial tissues, organs and perhaps even in a protein “solder” that could be melted into wounds for sutureless healing.
MIT polymer engineer Ioannis Yannas says that the Wisconsin work is an important advance in understanding the structure of collagen. He cautions, however, that the findings don’t guarantee practical uses for artificial collagen. For one thing, the molecule must prove to be nontoxic. And there is a “big gap,” Yannas says, between knowing the chemical structure and developing a new biomaterial.
Brian Butcher-vice president for research at the Arthritis Foundation, which helped fund Raines’ research-says that the new insight into collagen “could have very important repercussions” for arthritis. The joint ailment is often the result of collagen-rich cartilage breaking down; Butcher sees the potential to develop better tools for detecting the destruction. In time, Butcher says, researchers might even learn how to replace or strengthen collagen structures in arthritic joints, reweaving the worn tissues with stronger stuff.
Couldn't make it to EmTech Next to meet experts in AI, Robotics and the Economy?Go behind the scenes and check out our video | <urn:uuid:9bf7f790-6a36-4e7a-b27f-15dc44d0524c> | 3.203125 | 540 | Truncated | Science & Tech. | 31.369647 | 95,635,751 |
muon(redirected from Anti-muon)
Also found in: Thesaurus, Encyclopedia.
Related to Anti-muon: Leptons
The negatively charged lepton that belongs to the second generation of elementary fermions and has a mass 207 times that of an electron and a mean lifetime of 2.2 × 10-6 second. Also called mu lepton.
[Earlier mu meson (from the use of the Greek letter mu, the equivalent of the Roman letter m of meson, to distinguish it from other mesons subsequently discovered, the class of particles to which it was formerly thought to belong).]
(General Physics) a positive or negative elementary particle with a mass 207 times that of an electron and spin . It was originally called the mu meson but is now classified as a lepton
[C20: short for mu meson]
an unstable lepton of mass approximately 207 times greater than the electron's mass. | <urn:uuid:4e808eb9-9aa9-45f5-bf4b-9b138228b264> | 2.859375 | 199 | Structured Data | Science & Tech. | 44.955 | 95,635,752 |
X-ray Laser Experiment Provides First Look at Changes in Atomic Structure that Support Superconductivity
An experiment at the Department of Energy’s SLAC National Accelerator Laboratory provided the first fleeting glimpse of the atomic structure of a material as it entered a state resembling room-temperature superconductivity – a long-sought phenomenon in which materials might conduct electricity with 100 percent efficiency under everyday conditions.
Jörg Harms/Max Planck Institute for the Structure and Dynamics of Matter
In a high-temperature superconducting material known as YBCO, light from a laser causes oxygen atoms (red) to vibrate between layers of copper oxide that are just two molecules thick. (The copper atoms are shown in blue.) This jars atoms in those layers out of their normal positions in a way that likely favors superconductivity. In this short-lived state, the distance between copper oxide planes within a layer increases, while the distance between the layers decreases.
Researchers used a specific wavelength of laser light to rattle the atomic structure of a material called yttrium barium copper oxide, or YBCO. Then they probed the resulting changes in the structure with an X-ray laser beam from the Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility.
They discovered that the initial exposure to laser light triggered specific shifts in copper and oxygen atoms that squeezed and stretched the distances between them, creating a temporary alignment that exhibited signs of superconductivity for a few trillionths of a second at well above room temperature – up to 60 degrees Celsius (140 degrees Fahrenheit). The scientists coupled data from the experiment with theory to show how these changes in atomic positions allow a transfer of electrons that drives the superconductivity.
New Views of Atoms in Motion
“This is a highly interesting state, even though it only exists for a short period of time,” said Roman Mankowsky of the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, who was lead author of a report on the experiment in the Dec. 4 print issue of Nature. “When the laser excites the material, it shifts the atoms and changes the structure. We hope these results will ultimately help in the design of new materials to enhance superconductivity.”
Sustaining such a state at room temperature would revolutionize many fields, making the electrical grid more efficient and enabling more powerful and compact computers. Traditional superconductors operate only at temperatures close to absolute zero. YBCO is one of a handful of materials discovered since 1986 that superconduct at somewhat higher temperatures; but they still have to be chilled to at least minus 135 degrees Celsius in order to sustain superconductivity, and scientists still don’t know what allows these so-called high-temperature superconductors to carry electricity with zero resistance.
A Powerful Tool for Exploring Superconductivity
Josh Turner, a SLAC staff scientist who has led other studies of YBCO at the LCLS, said powerful tools such as X-ray lasers have excited new interest in superconductor research by allowing researchers to isolate a specific property that they want to learn more about. This is important because high-temperature superconductors can exhibit a tangle of magnetic, electronic and structural properties that may compete or cooperate as the material moves toward a superconducting state. For example, another recently published LCLS study found that exciting YBCO with the same optical laser light disrupts an electronic order that competes with superconductivity.
“What LCLS is now showing us is how these different properties change over short times,” Turner said. “We can actually see how the electrons or atoms are moving.”
Mankowsky said future experiments at LCLS could try to sustain the superconducting state for longer periods, use a combination of experimental techniques to study how other properties evolve in the transition into the superconducting state and explore whether the same structural changes are at work in other high-temperature superconductors.
Researchers from the National Center for Scientific Research in France, Paul Scherrer Institute in Switzerland, Max Planck Institute for Solid State Research in Germany, Swiss Federal Institute of Technology, College of France, University of Geneva, Oxford University in the United Kingdom, the Center for Free-Electron Laser Science in Germany, and University of Hamburg in Germany also participated in the study. The work was supported by the European Research Council, German Science Foundation, Swiss National Superconducting Center and Swiss National Science Foundation.
SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, Calif., SLAC is operated by Stanford University for the U.S. Department of Energy's Office of Science. For more information, please visit slac.stanford.edu.
SLAC National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.
Andrew Gordon | newswise
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
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Systems Approach to Natural and Artificial Plankton Communities by Continuous Cultures
Shortly after the invention of the microscope (about 1590 by Z. Jansen) Antony van Leeuwenhoek (1632–1723) was the first to observed infusoria in a drop of water. Since that time and since the first use of plankton gauze nets by the physiologist, Johannes Müller (1801–1858), the organisms in the plankton of aquatic environments have fascinated generations of scientists and amateurs. Every child looking for the first time in a microscope is spellbound by this living world of crawling and hopping water fleas, rotating wheel and slipper animalcules, and bizarre by shaped algae. What a contradiction to the formerly prevailing conception of a monotonous and simple structure of this pelagic environment! This apparent simplicity, however, seemed to be a good starting point for many scientists to study structure, function, and regulation of this community as a model for more complicated ecosystems. Hutchinson (1961) with his formulation of the “paradox of the plankton” illuminated this inconsistency. Meanwhile, with the publication of volumes such as Complex Interactions in Lake Communities (Carpenter 1988) and Plankton Ecology (Sommer 1989a), the specific character of this system is approached more closely. It is not its simplicity which makes the plankton a good candidate for model studies but its applicability to quantitative and experimental studies. This community has lost none of its fascination.
KeywordsActivate Sludge Continuous Culture Sewage Treatment Plant Plankton Community Chemostat Culture
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WASHINGTON (AP) — Heat-trapping greenhouse gases in the atmosphere are building up so high, so fast, that some scientists now think the world can no longer limit global warming to the level world leaders have agreed upon as safe.
New figures from the U.N. weather agency Monday showed that the three biggest greenhouse gases not only reached record levels last year but were increasing at an ever-faster rate, despite efforts by many countries to reduce emissions.
As world leaders meet next week in South Africa to tackle the issue of climate change, several scientists said their projections show it is unlikely the world can hold warming to the target set by leaders just two years ago in Copenhagen.
“The growth rate is increasing every decade,” said Jim Butler, director of the U.S. National Oceanic and Atmospheric Administration’s Global Monitoring Division. “That’s kind of scary.”
Scientists can’t say exactly what levels of greenhouse gases are safe, but some fear a continued rise in global temperatures will lead to irreversible melting of some of the world’s ice sheets and a several-foot rise in sea levels over the centuries — the so-called tipping point.
The findings from the U.N. World Meteorological Organization are consistent with other grim reports issued recently. Earlier this month, figures from the U.S. Department of Energy showed that global carbon dioxide emissions in 2010 jumped by the highest one-year amount ever.
The WMO found that total carbon dioxide levels in 2010 hit 389 parts per million, up from 280 parts per million in 1750, before the start of the Industrial Revolution. Levels increased 1.5 ppm per year in the 1990s and 2.0 per year in the first decade of this century, and are now rising at a rate of 2.3 per year. The top two other greenhouse gases — methane and nitrous oxide — are also soaring.
The U.N. agency cited fossil fuel-burning, loss of forests that absorb CO2 and use of fertilizer as the main culprits.
Since 1990 — a year that international climate negotiators have set as a benchmark for emissions — the total heat-trapping force from all the major greenhouse gases has increased by 29 percent, according to NOAA.
The accelerating rise is happening despite the 1997 Kyoto agreement to cut emissions. Europe, Russia and Japan have about reached their targets under the treaty. But China, the U.S. and India are all increasing emissions. The treaty didn’t require emission cuts from China and India because they are developing nations. The U.S. pulled out of the treaty in 2001, the Senate having never ratified it.
While scientists can’t agree on what level of warming of the climate is considered dangerous, environmental activists have seized upon 350 parts per million as a target for carbon dioxide levels. The world pushed past that mark more than 20 years ago.
Governments have focused more on projected temperature increases rather than carbon levels. Since the mid-1990s, European governments have set a goal of limiting warming to slightly more than 2 degrees Fahrenheit (1.2 degrees Celsius) above current levels by the end of this century. The goal was part of a nonbinding agreement reached in Copenhagen in 2009 that was signed by the U.S. and other countries.
Temperatures have already risen about 1.4 degrees Fahrenheit (0.8 degrees Celsius) since pre-industrial times.
Massachusetts Institute of Technology professors Ron Prinn, Henry Jacoby and John Sterman said MIT’s calculations show the world is unlikely to meet that two-degree goal now.
“There’s very, very little chance,” Prinn said. “One has to be pessimistic about making that absolute threshold.” He added: “Maybe we’ve waited too long to do anything serious if two degrees is the danger level.”
Andrew Weaver at the University of Victoria, Granger Morgan of Carnegie Mellon University and Gregg Marland of Appalachian State University agreed with the MIT analysis that holding warming to two degrees now seems unlikely.
“There’s no way to stop it. There’s so much inertia in the system,” Morgan said. “We’ve committed to quite a bit of warming.”
Prinn said new studies predict that if temperatures increase by more than two degrees, the Greenland ice sheets will start an irreversible melting. And that will add to sea level rise significantly.
“Over the next several centuries, Greenland slowly melts away,” Weaver said.
World Meteorological Organization’s Greenhouse Gas Bulletin: http://bit.ly/vu04vB
National Oceanic and Atmospheric Administration’s Annual Greenhouse Gas Index: http://www.esrl.noaa.gov/gmd/aggi/ | <urn:uuid:d04b8d08-1b7d-4363-b506-cb31bc1218d3> | 3.25 | 1,000 | News Article | Science & Tech. | 54.267702 | 95,635,801 |
Pick up a handful of sand, and it flows through your fingers like a liquid. But when you walk on the beach, the sand supports your weight like a solid. What happens to the forces between the jumbled sand grains when you step on them to keep you from sinking?
An international team of researchers collaborating at Duke University have developed a new way to measure the forces inside materials such as sand, soil or snow under pressure.
Physicists are using this computerized 3-D rendering of beads in a box to serve as a model for soil, sand or snow. Colored lines show the network of forces as the virtual particles are pushed together. Thick red lines connect the particles that are experiencing the brunt of the force. By studying the forces inside granular materials as they're pressed, pushed or squeezed, the researchers hope to better understand phenomena like the jamming of grain hoppers or the early warning signs of earthquakes and avalanches.
Credit: Video courtesy of Nicolas Brodu.
Described in the March 5 issue of Nature Communications, the technique uses lasers coupled with force sensors, digital cameras and advanced computer algorithms to peer inside and measure the forces between neighboring particles in 3-D.
The new approach will allow researchers to better understand phenomena like the jamming of grain hoppers or the early warning signs of earthquakes and avalanches, said study co-author Nicolas Brodu, now at the French institute Inria.
Whether footprints in sand, or the force of gravity on a mountain slope, physicists have long sought to understand what happens inside granular materials as they're pressed, pushed or squeezed.
For centuries this simple question has been surprisingly difficult to answer. But more recently, thanks to advances in 3-D imaging techniques and the number-crunching power of computers, researchers are starting to get a better picture of what happens when granular materials like soil or snow are pushed together.
Brodu, along with physicists Robert Behringer of Duke University and Joshua Dijksman of Wageningen University in the Netherlands, describe how they use simple tools to measure the network of forces at it spreads from one particle to the next.
The researchers use a solution of hundreds of translucent hydrogel beads in a Plexiglass box to simulate materials like soil, sand or snow.
A piston repeatedly pushes down on the beads in the box while a sheet of laser light scans the box, and a camera takes a series of cross-sectional images of the illuminated sections.
Like MRI scans used in medicine, the technique works by converting these cross-sectional "slices" into a 3-D image.
Custom-built imaging software stacks the hundreds of thousands of 2-D images together to reconstruct the surface of each individual particle in three dimensions, over time. By measuring the tiny deformations in the particles as they are squeezed together, the researchers are able to calculate the forces between them.
The new approach will help researchers better understand a range of natural and manmade hazards, such as why farmworkers stepping into grain bins sometimes experience a quicksand effect and are suddenly sucked under.
"This gives us hope of understanding what happens in disasters like a landslide, when packed soil and rocks on a mountain become loose and slide down," Brodu said. "First it acts like a solid, and then for reasons physicists don't completely understand, all of a sudden it destabilizes and starts to flow like a liquid. This transition from solid to liquid can only be understood if you know what's going on inside the soil."
The team has already used results from their technique to create a new model for the way particulate matter behaves, which is concurrently published in the journal Physical Review E.
This research was supported by grants from the National Science Foundation (DMR1206351, DMS1248071), the National Aeronautics and Space Administration (NNX10AU01G), and the U.S. Army Research Office (W911NF-1-11-0110).
CITATION: "Spanning the Scales of Granular Materials through Microscopic Force Imaging," Brodu, N., J. A. Dijksman and R. P. Behringer. Nature Communications, March 2015. DOI: 10.1038/ncomms7361
Robin Ann Smith | EurekAlert!
Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
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20.07.2018 | Materials Sciences | <urn:uuid:f2bcb706-a984-41a7-98e8-7b28a20939aa> | 4.25 | 1,465 | Content Listing | Science & Tech. | 42.405357 | 95,635,802 |
As we know that the Session is used to maintain the session between request. Session object is responsible to hold the conversational state across multiple requests.
The listener HttpSessionAttributeListener is an interface and extends the java.util.EventListener class. This listener will be called by the container whenever there there will be change to the attribute list on the servlet session of a web application. This listener is used when we want to know when a attribute has been added in a session, when a attribute has been removed and when it is replaced by another attribute. We can also say that this attribute is used when the developer is interested to be notified when the session attribute changes. Now you may be wondering what is an attribute. An attribute is an object set or you can simply say that it is name/value pair where the name refers to a String and a value refers to the Object.
javax.servlet.http.HttpSessionAttributeListener interface has following methods:
In the above methods you can see that we have used HttpSessionBindingEvent class as a parameter to the above methods. This class is a event class which is used for notifications when the changes are made to the attributes of in a session.
The class HttpSessionBindingEvent has two methods: | <urn:uuid:a0498d86-27a7-47b6-b8ba-ffc1b45d79ef> | 3.09375 | 262 | Documentation | Software Dev. | 43.385667 | 95,635,808 |
5,000 today), the Western Black Rhino was stated extinct in 2011. And the last male Northern White Rhino died this March in Sudan. Overall, rhinos in South Africa are being eliminated at a rate of more than 3 each day. If that continues, rhinos will be extinct in SouthAfrica by 2025. But networking and sensing unit technology, in combination with analytics, are now using methods to better manage populations of these animals and intercept pending risks. By linking sensing units to the cloud(public or personal)over low-power networks, these tech conservationists can provide essential intelligence on human activities near secured animals and help intercept poachers before they can do hurt-- both to the animals and the rangers securing them.Eyes and ears and clouds For a few years now, The Lindbergh Foundation's Air Shepherd program has actually utilized a combination of drones and information analytics in a South African trial to secure rhinos. That program has been broadened to elephant security in Malawi and Zimbabwe with crowdfunding.Further Reading Tech vs. fear: Drones and information combat a new battle versus poachers As Ars reported in 2015, Air Shepherd utilizes a mix of regional intelligence and smart image processing from drone sensor information to develop a design for exactly what's going on around and within the parks its crews protect. Based on animal motion patterns and the distance of human hazards, the drones are deployed to offer rangers advance caution of poachers'motions. But Air Shepard's drones require experienced pilots, and drones-- while frequently an effective deterrent-- can't constantly be on station to detect poaching attempts.So another effort at South Africa's Welgevonden Video game Reserve has attempted a various sort of IoT technique, tracking the behavior of other herd animals( such as zebras, impalas and gazelles). These displays function as "sentinels," basically watching for variations in animal movement in reaction to different possible dangers. The Welgevonden experiment, based on a cooperation with Wageningen University in the Netherlands and IBM, tracks the movements of these collared herbivores by making use of collars sending data through a 3G cordless network, and the effort inputs that data into an IBM Watson system in the cloud. The analytics of the Watson IoT platform are being trained to discover the distinction in habits in herd animals based on whether they are being available in contact with natural predators, travelers, or prospective poachers.While the IBM Watson service has actually worked so far, it remains reliant on a connection to the cloud. And for much of Africa, Web connection is not exactly guaranteed-- especially in wildlife areas, where it might depend on high-latency satellite connections or sparsely released cellular networks. Private cordless networks can provide a local backbone for communications, however there still needs
to be some sort of back-end connection for a cloud-driven IoT service to work. | <urn:uuid:9f3e9e98-d332-4848-9afb-a66446fd19eb> | 3.109375 | 586 | Truncated | Science & Tech. | 28.647538 | 95,635,814 |
Molecular chlorine, from sea salt released by melting sea ice, reacts with sunlight to produce chlorine atoms. These chlorine atoms are highly reactive and can oxidize many constituents of the atmosphere including methane and elemental mercury, as well activate bromine chemistry, which is an even stronger oxidant of elemental mercury. Oxidized mercury is more reactive and can be deposited to the Arctic ecosystem.
Jin Liao checks the instrumentation in Barrow, Alaska, during a research trip to measure molecular chlorine in the atmosphere. Liao is the first author of the study, published January 12, 2014, in the Advance Online Publication of Nature Geoscience
The study is the first time that molecular chlorine has been measured in the Arctic, and the first time that scientists have documented such high levels of molecular chlorine in the atmosphere.
“No one expected there to be this level of chlorine in Barrow or in polar regions,” said Greg Huey, a professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology in Atlanta.
The study was published January 12 in the journal Nature Geoscience and was supported by the National Science Foundation (NSF), part of the international multidisciplinary OASIS program.
The researchers directly measured molecular chlorine levels in the Arctic in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. At first the scientists were skeptical of their data, so they spent several years running other experiments to ensure their findings were accurate.
The level of molecular chlorine above Barrow was measured as high as 400 parts per trillion, which is a high concentration considering that chlorine atoms are short –lived in the atmosphere because they are strong oxidants and are highly reactive with other atmospheric chemicals.
Molecular chlorine concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone may be required for molecular chlorine formation.
Previous Arctic studies have documented high levels of oxidized mercury in Barrow and other polar regions. The major source of elemental mercury in the Arctic regions is coal-burning plants around the world. In the spring in Barrow, ozone and elemental mercury are often depleted from the atmosphere when halogens — chlorine and bromine — are released into the air from melting sea ice.
“Molecular chlorine is so reactive that it’s going to have a very strong influence on atmospheric chemistry,” Huey said.
Chlorine atoms are the dominant oxidant in Barrow, the study found. The area is part of a region with otherwise low levels of oxidants in the atmosphere, due to the lack of water vapor and ozone, which are the major precursors to making oxidants in many urban areas.
In Barrow, snow-covered ice pack extends in every directly except inland. The ultimate source of the molecular chlorine is the sodium chloride in sea salt, Huey said, most likely from the snow-covered ice pack. How the sea salt is transformed into molecular chlorine is unknown.
“We don’t really know the mechanism. It’s a mystery to us right now,” Huey said. “But the sea ice is changing dramatically, so we’re in a time where we have absolutely no predictive power over what’s going to happen to this chemistry. We’re really in the dark about the chlorine.”
Scientists do know that sea ice is rapidly changing, Huey said. The sea ice that lasts from one winter to the next winter is decreasing. This has created a larger area of melted ice, and more ice that comes and goes with the seasons. This seasonal variation in ice could release more molecular chlorine into the atmosphere.
“There is definite climate change happening in the Arctic,” Huey said. “That’s changing the nature of the ice, changing the volume of the ice, changing the surface area and changing the chemistry of the ice.”
Brett Israel | Newswise
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
Drones survey African wildlife
11.07.2018 | Schweizerischer Nationalfonds SNF
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences | <urn:uuid:73fb1ed9-a9cf-48ac-aa24-8d9e9b99b6d0> | 3.796875 | 1,461 | Content Listing | Science & Tech. | 36.613662 | 95,635,815 |
The 2015-16 El Nino did impact the atmosphere of the globe, besides causing severe heat and drought in tropical regions of South America, Africa and Indonesia.
The spikes recorded by OCO-2 indicated that the carbon dioxide emissions got a 50 percent increase in the year 2015-16 as compared to the average carbon emissions of preceding years. Now, scientists think they know why.
"The team's findings imply that if future climate brings more or longer droughts, as the last El Nino did, more carbon dioxide may remain in the atmosphere, leading to a tendency to further warm Earth", Eldering added.
Key drivers of this change in carbon emissions were lower precipitation in South America and increased temperatures in Africa.
After analyzing 28 months of data collected from OCO-2, lead author of the study, Junjie Liu of NASA's Jet Propulsion Laboratory (JPL), revealed that the three tropical reasons released 2.5 (a billion tonnes) more carbon into the atmosphere in 2015-16 than they did in 2011.
The Latest The Goldman Sachs Group, Inc. (GS) Insider Trading Activity
The France-based Natixis has invested 1.54% in Goldman Sachs Group Inc (NYSE:GS). (The) by 33.1% in the 2nd quarter. The Independent Portfolio Consultants Inc holds 13,413 shares with $2.98 million value, up from 9,371 last quarter.
Colorado State University's Scott Denning says a vicious cycle might await if future climates reflect similar conditions of heat and drought.
One of the crowning achievements of modern environmental science is the Keeling curve, the detailed time series of the concentration of atmospheric carbon dioxide (CO2) begun in 1958 that has enabled deep insights into the mechanisms of global climate change. Data from the satellite will help scientists understand the global carbon cycle-and how that cycle may change in response to global warming. The satellite can observe atmospheric Carbon dioxide and photosynthesis over large geographical areas.
Tropical forests in eastern Africa had normal rainfall, but the temperatures were much greater than normal. Higher-than-average temperatures combined with those climatic conditions to stress massive amounts of plant life, meaning there was less photosynthesis than normal - and thus less carbon was removed from the atmosphere than normal.
In tropical Asia, the increased carbon release was mostly due to biomass burning.
Another study that was part of a collection of five on the topic in Science, found "striking" seasonal changes in the carbon cycle across the Northern Hemisphere. Before then, Earth's atmosphere naturally contained about 595 gigatons of carbon in the form of carbon dioxide. With its impressive collection of observational capabilities, OCO-2 will enable measurements of atmospheric Carbon dioxide to be made with sufficient precision, resolution, and coverage to faithfully characterize its sources and sinks globally over the seasonal cycle, a long-standing goal in atmospheric and climate science. | <urn:uuid:52c376d7-0ff7-44af-8997-00dc24c66efa> | 3.703125 | 595 | News Article | Science & Tech. | 36.971309 | 95,635,835 |
Temporal range: early Triassic–recent 250–0 Ma
|A pygmy mole-cricket|
The Caelifera are a sub-order of Orthopteran insects. They include the grasshoppers and grasshopper-like insects, as well as other superfamilies classified with them: the ground-hoppers (Tetrigoidea) and pygmy mole crickets (Tridactyloidea). The latter should not be confused with the mole crickets (Gryllotalpidae), which belong to the other Orthopteran sub-order Ensifera.
Subdivisions and their distribution
The Caelifera includes some 2,400 valid genera and about 11,000 known species. Many undescribed species probably exist, especially in tropical forests. The Caelifera have a predominantly tropical distribution (as with most Orthoptera) with fewer species known from temperate climate zones. Caelifera are divided into two infraorders: the more basal Tridactylidea and the Acrididea or grasshopper-like species. This latter name is derived from older sources, such as Imms, which placed the "short-horned grasshoppers" and locusts at the family level (Acrididae).
- Infraorder Tridactylidea
- Infraorder Acrididea (superfamily group Acridomorpha includes all except superfamily Tetrigoidea)
- Acridoidea MacLeay, 1821: most grasshoppers – World-wide - approx. 10,000 species in the Acrididae alone
- Eumastacoidea Burr, 1899: "monkey grasshoppers" - Americas, Africa, Australasia
- Locustopsoidea Handlirsch, 1906 †
- Pneumoroidea Blanchard, 1845: "bladder grasshoppers" - Africa
- Pyrgomorphoidea (monotypic) B. von Wattenwyl, 1882: "gaudy grasshoppers" - all tropical/subtropical continents
- Tanaoceroidea (monotypic) Rehn, 1948: "desert long-horned grasshoppers" - north America
- Tetrigoidea (monotypic) Serville, 1838: groundhoppers or "grouse locusts" - all continents except Antarctica
- Trigonopterygoidea Walker, 1870: "razor-backed bush-hoppers" - central America, south-east Asia
The phylogeny of the Caelifera, is described in detail for grasshoppers, with 6 out of 8 extant superfamilies shown here as a cladogram. Like the Ensifera, Caelifera and all of its superfamilies appear to be monophyletic.
Economic significance and terminology
A number of species, especially in the Acridoidea, are significant agricultural pests, but not all of them are locusts: a non-taxonomic term referring to species whose populations which may change morphologically when crowded and show swarming behaviour. Examples of agricultural grasshopper pests that are not called locusts include the Senegalese grasshopper and certain species in the Pyrgomorphidae, notably the variegated grasshopper (Zonocerus variegatus).
- Zeuner, F. E. (1939). Fossil Orthoptera Ensifera. British Museum Natural History. OCLC 1514958.
- ITIS: Caelifera (retrieved 2 August 2017)
- Rowell, Hugh; Flook, Paul (2001). "Caelifera: Shorthorned Grasshoppers, Locusts and Relatives". Tree of Life web project. Retrieved 20 July 2017.
- Imms AD, rev. Richards OW & Davies RG (1970) A General Textbook of Entomology 9th Ed. Methuen 886 pp.
- Ragge DR (1965). Grasshoppers, Crickets & Cockroaches of the British Isles. F Warne & Co, London. p. 299.
- ITIS: Acrididea (Retrieved 23/7/2017)
- Orthoptera Species File: infraorder Acrididea (Retrieved 20/7/2017)
- Flook, P. K.; Rowell, C. H. F. (1997). "The Phylogeny of the Caelifera (Insecta, Orthoptera) as Deduced from mtrRNA Gene Sequences". Molecular Phylogenetics and Evolution. 8 (1): 89–103. doi:10.1006/mpev.1997.0412. PMID 9242597.
- Uvarov BP (1966) Grasshoppers & Locusts. A Handbook of General Acridology Cambridge University Press, London 1:481 pp.
- Media related to Caelifera at Wikimedia Commons
- Data related to Caelifera at Wikispecies
- Tolweb: Caelifera
- Orthoptera Species File: Caelifera (accessed 20 July 2017)
- Palaeobiology database: Caelifera Ander 1936 (accessed 20 June 2017)
- ITIS: Caelifera (accessed 20 June 2017)
- NCBI: Caelifera (accessed 20 June 2017) | <urn:uuid:4f978fb6-8330-4a26-9819-c9b4956593e4> | 3.125 | 1,162 | Knowledge Article | Science & Tech. | 27.316616 | 95,635,838 |
The Susquehanna Flats, a large bed of underwater grasses near the mouth of the Susquehanna River, virtually disappeared from the upper Chesapeake Bay after Tropical Storm Agnes more than 40 years ago. However, the grasses mysteriously began to come back in the early 2000s. Today, the bed is one of the biggest and healthiest in the Bay, spanning some 20 square miles. A new study by scientists at the University of Maryland Center for Environmental Science explores what's behind this major comeback.
"This is a story about resilience," said Donald Boesch, president of the University of Maryland Center for Environmental Science. "It's a powerful example of how organisms in ecosystems once given a chance can make themselves resistant to stresses and changes."
Underwater grasses are important to the Bay because they provide habitat for juvenile fish and enhance water clarity by trapping and removing sediment from the water. Historically extolled by trophy fisherman and waterfowl enthusiasts as prime wildlife habitat, researchers believe that the underwater grass beds at the shallow Susquehanna Flats began to decline in the 1960s when polluted runoff from a rapidly developing watershed overwhelmed the Bay's waters with nutrients, causing algae blooms that blocked out much-needed sunlight for underwater plants.
"Underwater grasses are sensitive to water quality so they are a direct indicator of the Bay's health," said lead-author Cassie Gurbisz of the Center's Horn Point Laboratory. "The fact that they came back means something good is happening. It's important, however, for us to understand how they came back so we can use that information to support restoration in other areas."
With SAV already stressed by nutrient pollution, it was Tropical Storm Agnes in 1972—a three-day weather event in June that dumped up to 19 inches of rain on the region and an estimated 30 million tons of sediment into the Chesapeake Bay—that was the final blow that destroyed the bed. A torrent of polluted floodwaters and sediment overwhelmed the beds, and the submerged plants virtually disappeared for nearly three decades. That is until the early 2000s when the underwater grasses, also called submerged aquatic vegetation (SAV), rapidly recolonized nearly the entire region.
"This was a large and abrupt resurgence. The Susquehanna Flats SAV bed is gigantic--the largest in the Chesapeake, with multiple species of grasses," said Professor Michael Kemp. "When you're out on the Flats in summer at low tide, you see these plants at the water surface all around you, and it's a truly awe inspiring scene."
It was clear that the extreme flood event following Tropical Storm Agnes triggered the historic demise of the grasses at Susquehanna Flats, however the extended absence of SAV for over 30 years—and the rapid comeback in the last decade—was puzzling to scientists. Researchers analyzed recent and historical data to try to develop a model that explains this resurgence. Monitoring programs throughout the years provided a wealth of information on underwater grasses (since 1958), water quality (since 1984) and even climate-related variables, such as temperature and rivers discharge dating back to the late 1800s.
Researchers found that modest reductions in nutrient pollution to the Bay beginning in the late 1980s had led to long-term improvements to water clarity and the amount of light available for plants to grow underwater. A dry period from 1997-2002 combined with the absence of major storm events provided ideal conditions for new plant growth, and a critical threshold for the amount of light reaching the plants was crossed. As a result, the bed began to expand and colonize deeper water.
"Exceptional growing conditions during the drought period allowed the system to overcome turbid water and served to kick start a rapid resurgence," said Cassie Gurbisz. "Light availability is the most important factor in the growth of submersed plants."
Then the plants took over with a process called positive feedback. That is, once given a chance, grass beds can improve their own growing conditions by helping sediment drop to the bottom and stay there (increasing the amount of sunlight that can reach their leaves), and using excess nutrients in the water to grow. The researchers found lower nitrogen concentrations and less turbidity in the grass beds than the surrounding waters.
These feedbacks also affect a plant bed's resilience, or its ability to resist disturbances such as storms and rebound after they pass. The researchers note that in the decade before Tropical Storm Agnes, the bed was deteriorating. As a result, feedbacks were not very strong and the bed was unable to stand up to Agnes. The present bed is, evidently, more resilient. When major floodwaters flowed from the Susquehanna River in Fall 2011, a portion of the bed was lost. However, the remaining bed has continued to thrive and expand.
"These processes and patterns are not unique to Susquehanna Flats. Similar trends have been suggested for the Mid-Atlantic Coastal Bays and Northern Europe alike," said Kemp. "Our broader motivation lies in the idea that the methods and models used here can be applied elsewhere to explore similar plant bed dynamics around the world."
The paper, "Unexpected resurgence of a large submersed plant bed in Chesapeake Bay: Analysis of time series data," by Cassie Gurbisz and Michael Kemp of the University of Maryland Center for Environmental Science's Horn Point Laboratory, was published in the March 2014 issue of Limnology and Oceanography.
Univertsity of Maryland Center for Environmental Science The University of Maryland Center for Environmental Science unleashes the power of science to transform the way society understands and manages the environment. By conducting cutting-edge research into today's most pressing environmental problems, we are developing new ideas to help guide our state, nation, and world toward a more environmentally sustainable future through five research centers—the Appalachian Laboratory in Frostburg, the Chesapeake Biological Laboratory in Solomons, the Horn Point Laboratory in Cambridge, the Institute of Marine and Environmental Technology in Baltimore, and the Maryland Sea Grant College in College Park. http://www.umces.edu
Amy Pelsinsky | Eurek Alert!
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Life Sciences
18.07.2018 | Life Sciences
18.07.2018 | Information Technology | <urn:uuid:e71b6004-eb53-4719-979c-910db528063e> | 3.59375 | 1,914 | Content Listing | Science & Tech. | 37.602042 | 95,635,860 |
The recent discovery of a planet around the star closest to Earth’s sun has raised hopes that life might exist around the sun’s nearest neighbor, but researchers now find that this world might frequently experience extinction-level “superflares” from its star.
In August, scientists revealed the existence of an alien world around Proxima Centauri, a red dwarf star more than 600 times dimmer than the sun that lies just 4.2 light-years from Earth’s solar system. This exoplanet, known as Proxima b, could be rocky and about the size of Earth. It also lies in its star’s “habitable zone,” the area around the star warm enough for the planet to potentially host liquid water on its surface. Since there is life virtually wherever there is water on Earth, being positioned in the habitable zone would raise the chance that Proxima b is home to life as it is known on Earth.
However, life likely needs more than just warmth and water to survive. Past research has found that many exoplanets are subject to superflares from their host stars, which can be up to thousands of times more powerful than ones seen so far from the sun. These massive flares could scour life from planets, especially those close to their stars, like Proxima b, which orbits Proxima Centauri at a distance one-tenth that between Mercury and the sun.
To find out what effects flares might have on exoplanets, study author Dimitra Atri, a research scientist at the Blue Marble Space Institute of Science in Seattle, ran computer simulations modeling the interactions of planetary atmospheres with protons released during flares. These simulations included a wide range of flare strengths, planetary atmospheric thicknesses, orbital distances from stars and planetary magnetic field strengths, all factors that can influence how much radiation the surface of an exoplanet might receive.
Atri found that if Proxima b had an atmosphere and magnetic field like Earth’s, superflares would not have any significant effect on the planet’s biosphere. However, if Proxima b’s atmosphere is slightly thinner, or its magnetic field is much weaker, the alien world would likely receive “extinction-level” doses of radiation from superflares, Atri discovered.
“I would say that it is too premature to call Proxima b habitable,” Atri told Space.com. “There are many factors that would decide whether such a planet can sustain a biosphere. More data will help clarify the situation.”
Prior work found that red dwarf stars such as Proxima Centauri, also known as M stars, constitute up to 70 percent of the stars in the cosmos, making them potentially key places to search for life. Because M stars are dim, the habitable zones of red dwarfs lie near these cold stars, often closer than the distance of Mercury from the sun. These findings suggest that superflares might pose a major threat to life on worlds in red dwarf habitable zones.
“Here is how I think about this — the weather in Fukushima [Japan] right now is in the mid-50s [Fahrenheit, or about 13 degrees Celsius], a bit chilly but a good temperature to spend time there,” Atri said, referring to the site of a nuclear power plant disaster in 2011. “However the radiation dose there is too high, which would make living there too risky. The same is true with ‘habitable’ planets around M stars. They might have an optimum temperature, but stellar flares would produce very high radiation doses at regular intervals.
“One important aspect of this work is highlighting the critical importance of having a significant planetary magnetic field and good atmospheric shielding,” Atri said. “With these two factors, even the most extreme stellar flares will not have much impact on a primitive biosphere.”
Atri did note that previous research has found that some microbes on Earth can withstand very high doses of radiation, and that life on other worlds might also be radiation-resistant. “I am working with some experimentalists to reproduce such high radiation doses in a lab and see how different microbes respond,” Atri said. “I think that would tell us a lot about potential life on planets such as Proxima b.”
The new research appeared online on Sept. 30 in the journal Monthly Notices of the Royal Astronomical Society.
* Originally published on December 12, 2016, at Space.com. Copyright © Charles Q. Choi. | <urn:uuid:734b86ab-c721-430d-ad39-0fe746c7acf6> | 3.828125 | 952 | News Article | Science & Tech. | 44.547942 | 95,635,865 |
Tritium Systems Test Assembly (TSTA)
The Tritium Systems Test Assembly (TSTA) was a facility at Los Alamos National Laboratory dedicated to the development and demonstration of technologies required for fusion-relevant Deuterium-Tritium processing. The facility design was launched in 1977. It was commissioned in 1982 and first tritium was processed in 1984. The maximum tritium inventory was 140 grams. Many publications were generated during this project.
- Anderson, J. L., T. Naito, et al. (1988). "Experience of TSTA milestone runs with 100 grams-level of tritium." Fusion Technology 14(2): 438-443.
- Bartlit, J. R., J. L. Anderson, et al. (1983). Subsystem Cost Data for the Tritium Systems Test Assembly. 10th Symposium on Fusion Engineering, Philadelphia.
- Sherman, R. H., J. R. Bartlit, et al. (1988). "Operation of the TSTA Isotope-Separation System with 100 Gram Tritium." Fusion Technology 14(2): 1273-1276.
- Willms, R. S., D. J. Taylor, M. Enoeda and K. Okuno; “Practical-Scale Tests of Cryogenic Molecular Sieve for Separating Low-Concentration Hydrogen Isotopes from Helium”, Fusion Engineering and Design 28, 386-391 (1995).
- Willms, R. S. and K. Okuno; “Recovery of Hydrogen from Impurities Using a Palladium Membrane Reactor”, Proceedings of the 15th IEEE Symposium on Fusion Engineering, Hyannis, Massachusetts, 85-90, October 11-15, 1993.
- Konishi, S., R. S. Willms, et al.; “Extended Operation of Reactor-Scale Fusion Fuel Loop Under US-Japan Collaboration”; Proceedings of the 15th IEEE Symposium on Fusion Engineering, Hyannis, Massachusetts, 204-207, October 11-15, 1993.
- Willms, R.S., K. Kobayashi, Y. Iwai, T. Hayashi, S. O'hira, M. Nishi, D. Hyatt and R.V. Carlson; “Behavior of tritium in the TSTA test cell combined with operation of the Experimental Tritium Cleanup (ETC) system”; Fusion Engineering and Design, 61-62, 575 - 583 (2002). | <urn:uuid:26fff2c1-6b1f-4925-aa88-9f1ba06bd861> | 2.875 | 544 | Knowledge Article | Science & Tech. | 68.751752 | 95,635,870 |
Photodegradation of Pesticides on Plant and Soil Surfaces
Sunlight photodegradation is one of the most destructive pathways for pesticides after their release into the environment. Plant surfaces, especially leaf surfaces, are the first reaction environment for a pesticide molecule after application, and spray drift would indirectly present a similar situation. Photolysis on soil surfaces becomes important when a pesticide is directly applied to soil or not significantly intercepted by plants, providing that the leaf cover does not shade the ground from sunlight. Because the foliar interception of pesticides depends on plant species and usually increases with their growth stage (Linders et al. 2000), the importance of soil photolysis is considered to be lessened when plants become mature. Spray drift after pesticide application or washoff from plants by rain is the indirect route by which a pesticide reaches the soil.
KeywordsHumic Substance Clay Surface Direct Photolysis Soil Thin Layer Ester Cleavage
Unable to display preview. Download preview PDF. | <urn:uuid:028cd79d-6de5-40f4-b977-8cc42266122b> | 3.609375 | 200 | Truncated | Science & Tech. | 19.871039 | 95,635,872 |
Root chemistry and soil fauna, but not soil abiotic conditions explain the effects of plant diversity on root decomposition
Plant diversity influences many ecosystem functions including root decomposition. However, due to the presence of multiple pathways via which plant diversity may affect root decomposition, our mechanistic understanding of their relationships is limited. In a grassland biodiversity experiment, we simultaneously assessed the effects of three pathways—root litter quality, soil biota, and soil abiotic conditions—on the relationships between plant diversity (in terms of species richness and the presence/absence of grasses and legumes) and root decomposition using structural equation modeling. Our final structural equation model explained 70% of the variation in root mass loss. However, different measures of plant diversity included in our model operated via different pathways to alter root mass loss. Plant species richness had a negative effect on root mass loss. This was partially due to increased Oribatida abundance, but was weakened by enhanced root potassium (K) concentration in more diverse mixtures. Equally, grass presence negatively affected root mass loss. This effect of grasses was mostly mediated via increased root lignin concentration and supported via increased Oribatida abundance and decreased root K concentration. In contrast, legume presence showed a net positive effect on root mass loss via decreased root lignin concentration and increased root magnesium concentration, both of which led to enhanced root mass loss. Overall, the different measures of plant diversity had contrasting effects on root decomposition. Furthermore, we found that root chemistry and soil biota but not root morphology or soil abiotic conditions mediated these effects of plant diversity on root decomposition.
KeywordsSpecies richness Functional groups Root litter Jena Experiment SEM
The Jena Experiment was funded by the German Science Foundation (DFG, FOR 1451) and was supported by the Friedrich-Schiller-University Jena and the Max Planck Society. We thank the gardeners of the Jena Experiment for maintaining the plots and student helpers for the field work and sample preparation.
Root mass loss, root C:N ratio, and soil water content are deposited at the Jena Experiment database and will be accessible via Dryad Digital Repository http://dx.doi.org/10.5061/dryad.6k23f (Chen et al. 2017). The rest of the data are deposited at the Jena Experiment database and will be deposited at Pangaea (http://www.pangaea.de).
Author contribution statement
LM, JR, AG, MSL, and AW designed the experiment. HC, CF, OGM, NH, and ML collected the data. HC analyzed the data and wrote the manuscript with input from KB and AW. All authors provided input on the final written manuscript.
Compliance with ethical standards
The Jena Experiment was funded by the German Science Foundation (DFG, FOR 1451). LM was funded by the Netherlands Organisation for Scientific Research (NWO, Vidi Grant 864.14.006). MSL was funded by the DFG (Gl262/14 and Gl262/19). YO was funded by the DFG (Oe516/3-2), WW was funded by the DFG (Wi1601/4) and the Swiss National Science Foundation (SNF, 200021E-131195/1).
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable institutional and/or national guidelines for the care and use of animals were followed.
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In this post we will discuss about what are Extensions method in C#.Net.
If your source code is available then there are different ways to extend the class like through inheritance you can add functionality to the objects. But what will happen if you do not have the source code. In C#.Net Extensions method will help us in changing the class without having the source code.
Extension methods are static methods that can appear to be part of a class without actually being in the source code for the class.
Suppose we have a class name as Employee which class has some methods defined in it. But we want another method like AddBonous (decima bonousAmount). But we do not have the source code, so we can not directly change in the assembly.
To add the method we have to create a static class as well as we have to add the method AddBonous as a static method like below:
public static class EmployeeExtension
public static void AddBonous (this Employee employee, decimal bonousAmount)
employee.Salary += bonousAmount;
Here the first parameter is the type that is being extended preceded by the this keyword.
This is what tells the compiler that this method is part of the Employee type. Here Employee is the type that is being extended. In the extension method you have access to all the public methods and properties of the type being extended.
But while using the method the first parameter will not come means you can access the method like obj.AddBonous (5000);
Event through the method is a static method we have to use the standard instance method syntax to call the method. But If the extension method has the same name as a method in the class, the extension method will never be called. | <urn:uuid:a047feb2-0e59-4e3b-b5fe-8a20ef1fdca0> | 3.453125 | 363 | Tutorial | Software Dev. | 55.686333 | 95,635,912 |
The cortex consists of six different layers, which vary in their anatomical and physiological properties. It plays a key role in the cognitive capacities of the brain. Since the cortical layers are segregated functionally, we could potentially say something about the neural processes that take place when an area is activated if we could see different signals in the different layers.
A: The stimulus used to elicit positive and negative BOLD responses in the visual cortex;
B: Positive and negative BOLD responses in monkey primary visual cortex to a visual stimulus;
C: The cerebral blood volume (CBV) response to a visual stimulus is increased in the entire primary visual cortex.
Jozien Goense / Max Planck Institute for Biologische Cybernetics, Tübingen
Jozien Goense from the Max Planck Institute for Biological Cybernetics in Tübingen, Germany and her colleagues used functional Magnetic Resonance Imaging (fMRI) to observe these layer-specific neural processes within the cortex and found different mechanisms for fMRI response increases and decreases as well as cortical layer-dependent differences in the neurovascular coupling mechanism.
The cortex is the outermost layer of the brain and plays a key role in perception, memory, attention, thought, language and consciousness. In mammals, it consists of six horizontal layers, each with different anatomical and physiological properties and different connectivity. These layers have so far been elusive to study in vivo, for several reasons, like a lack of spatial resolution in functional Magnetic Resonance Imaging (fMRI), the inability to see deeper layers with various optical methods, or difficulty in determining the exact recording depth of electrodes. Therefore, if we can visualize the signals in the different layers, it would allow us to better probe the cortical circuitry, for example to determine the processing steps that occur between the input and output of a given cortical area.
Functional Magnetic Resonance Imaging (fMRI) is one of the most used tools to observe the functional activity of the brain. fMRI is a non-invasive method that measures brain activity by detecting associated changes in blood flow and oxygen consumption. The primary form of fMRI uses the blood-oxygenation-level-dependent (BOLD) contrast, which reflects the oxygen concentration in the blood, and through this indicates which brain areas are activated upon a certain stimulus. However, typical fMRI studies measure activation on the scale of a few millimeters and are not able to resolve the cortical layers. Furthermore, it is also not yet known if and how layer-specific neural activity is reflected in the BOLD-response. Other functional imaging methods that are less commonly used, but can shed light on this question, are based on the cerebral blood volume (CBV), whereby the amount of blood in the activated brain region is measured, or based on cerebral blood flow (CBF). These various methods have different sensitivities and measure different aspects of the blood flow response upon neural activity.
Jozien Goense is a project leader in the Department for Physiology of Cognitive Processes headed by Nikos Logothetis at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany. She and her colleague Hellmut Merkle from the Laboratory of Functional and Molecular Imaging at the National Institutes of Health in Bethesda (USA), used high-resolution fMRI to measure BOLD-, CBV- and CBF responses to stimuli that elicit positive- and negative BOLD signals in the macaque primary visual cortex. They compared the activity patterns in response to excitatory stimuli, and stimuli that are known to give negative BOLD responses. Negative BOLD responses are reductions in the BOLD signal, often seen adjacent to stimulated regions. The negative BOLD signal is therefore thought to result from neuronal suppression.
They found that a negative BOLD response is not just the inverse of the positive response, but that it has a separate mechanism. Furthermore, the different layers responded differently to the stimuli. This indicates that the neurovascular coupling mechanism, which is the mechanism that provides the link between the neural signals and the BOLD-response, differs in the different layers and for the two stimuli. This means that potentially the layer-specific differences in the responses can be used to separate what kind of processes occur in the cortex.
These findings suggest different mechanisms for neurovascular coupling for BOLD increases and decreases as well as laminar differences in neurovascular coupling. The consequences of these findings are quite fundamental, since it may improve the interpretation of the BOLD signals in fMRI studies, and especially the negative one. Furthermore, it opens up the possibility to study neural processes within the cortical sheet, which would expand the applicability of fMRI and push it to smaller spatial scales than the ones it is currently used at.Original Publication:
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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20.07.2018 | Materials Sciences | <urn:uuid:77533387-7439-493e-a43d-1b90a99e8bdf> | 3.8125 | 1,554 | Content Listing | Science & Tech. | 28.212309 | 95,635,914 |
Dynamic SQL refers to SQL statements that are constructed and executed at runtime. Dynamic is the opposite of static. Static SQL refers to SQL statements that are fully specified, or fixed, at the time the code containing that statement is compiled. Dynamic PL/SQL refers to entire PL/SQL blocks of code that are constructed dynamically, then compiled and executed.
Time for a confession: I have had more fun writing dynamic SQL and dynamic PL/SQL programs than just about anything else I have ever done with the PL/SQL language. By constructing and executing dynamically, you gain a tremendous amount of flexibility. You can also build extremely generic and widely useful reusable code.
So what can you do with dynamic SQL and dynamic PL/SQL? Here are just a few ideas:
You can only execute queries and DML statements with static SQL inside PL/SQL. What if you want to create a table or drop an index? Time for dynamic SQL!
A common requirement of Internet applications is that users may be able to specify which columns they want to see and vary the order in which they see the data (of course, users don't realize they are doing so).
Rather than hardcoding business rules and formulas into your code, you can place that logic in tables. At runtime, you can generate and then execute the PL/SQL code needed to apply the rules.
Ever since ... | <urn:uuid:73731780-fabc-48b8-8896-75cc97902b69> | 2.84375 | 279 | Truncated | Software Dev. | 54.35021 | 95,635,929 |
To cite this page, please use the following:
· For print: . Accessed
· For web:
Found most commonly in these habitats: 8 times found in premontane rainforest, 6 times found in mature rainforest, 2 times found in treefall gap; premontane rainforest, 2 times found in Bamboo forest, 1 times found in riparian rainforest, 1 times found in rainforest.
Found most commonly in these microhabitats: 19 times ex sifted leaf litter, 1 times sifted litter.
Collected most commonly using these methods: 17 times maxiWinkler, 2 times winkler.
Elevations: collected from 276 - 710 meters, 557 meters average
AntWeb content is licensed under a Creative Commons Attribution License. We encourage use of AntWeb images. In print, each image must include attribution to its photographer and "from www.AntWeb.org" in the figure caption. For websites, images must be clearly identified as coming from www.AntWeb.org, with a backward link to the respective source page. See How to Cite AntWeb.
Antweb is funded from private donations and from grants from the National Science Foundation, DEB-0344731, EF-0431330 and DEB-0842395. c:0 | <urn:uuid:e220996b-134b-4d64-aabb-29fd1d6739bb> | 2.65625 | 273 | Knowledge Article | Science & Tech. | 51.821011 | 95,635,955 |
In this project we're going to produce a Flappy Bird clone called Crashy Plane. Flappy Bird might seem like a remarkably simple game when you’re playing it, but has a lot going on behind the scenes: there’s physics, animation, infinite scrolling, and more – it’s a worthy choice for a learning project.
Before you start, please download the assets for this project from https://github.com/twostraws/HackingWithSwift so you can follow along. If you haven't played Flappy Bird before, the concept is simple: tap the screen to keep your bird flying, and don't touch the floor of any pipes. In our game it'll be a plane with mountains as obstacles, but the idea is the same.
The assets you download are all licensed under CC0 / public domain, which means you can use them however you want without attribution. If you want to attribute the original authors, see the README.txt file in the zip. The game art comes from a designer called Kenney, who offers a huge selection of public domain game assets in return for a donation – if you're serious about making games you should definitely visit his home page.
All set? Great! Launch Xcode and create a new project from the game template. Choose Swift for your language and SpriteKit for the game technology, then name it Project36 and click Next then Finish. Before we go any further, please change its project settings so that it supports only iPhone in portrait – that’s the natural environment of Flappy Bird.
Get my latest video for free
Learn about value types, functional programming, and protocol-oriented programming in this new video – it's free! | <urn:uuid:5289c5da-14bb-437b-8ffc-be966283ebcc> | 2.984375 | 355 | Truncated | Software Dev. | 58.145625 | 95,635,957 |
Elephant Genome Provides Evidence to Boost Conservation Efforts
African savanna elephants in San Diego Zoo. In the middle is Swazi, the female elephant from which the reference genome was sequenced. Credit : San Diego Zoo Global
Elephants—the largest living terrestrial mammal—began walking the surface of the earth 5 to 10 million years ago in Africa. Today there are fewer than 500,000 elephants alive, making this group of iconic animals a highly protected species—especially in Africa where the perils of ivory-trade continue to threaten them. The shrinking population of elephants makes them an “isolated branch” in evolution, with only three currently recognized species: the Asian elephant, the African savannah elephant, and the African forest elephant.
A consortium of scientists led by researchers at the Broad Institute of MIT and Harvard, Harvard Medical School, Uppsala University, the University of Potsdam, and McMaster University used advanced sequencing technology to recover complete genomes from both living and extinct elephant species. In a paper published in Proceedings of the National Academy of Sciences today, the authors provide a comprehensive genomic portrait of not just the living elephants but also members of extinct mammoths and straight-tusked elephants, as well as the American mastodon, an extinct distant relative of the elephant family. The paper reveals that gene flow between elephant species was a common feature of their history, contrary to previous studies which represented their relationships as simple tree.
“This paper, the product of a grand initiative we started more than a decade ago, is far more than just the formal report of the elephant genome. It will be a reference point for understanding how diverse elephants are related to each other and it will be a model for conducting similar studies in other species groups,” said co-senior author Kerstin Lindblad-Toh, a senior director of vertebrate genomics at the Broad Institute and professor in comparative genomics at Uppsala University in Sweden. Lindblad-Toh was also one of the key organizers of the Elephant Genome Project (EGP) when it began in 2008. The EGP was a part of Broad Institute’s community-driven initiative, representing diverse stakeholders from the elephant genetics and conservation communities.
“There’s been a simmering debate in the conservation communities about whether African savannah and forest elephants are two different species,” said David Reich, another co-senior author at the Broad Institute who is also a professor at the Department of Genetics at Harvard Medical School (HMS) and a Howard Hughes Medical Institute Investigator. “Our data show that these two species have been isolated for long periods of time, making each worthy of independent conservation status.”
The paper confirms that the African savannah and forest elephants are two distinct species, findings that should help to make the case to protect both.
The Broad Institute generated the genomes for all the present-day elephants as well as a high-quality genome from an extinct 120,000-year-old straight-tusked elephant obtained from a sample prepared at the University of Potsdam in Germany. “This is one of the oldest high-quality genomes that currently exists for any species,” said Michael Hofreiter at the University of Potsdam in Germany, a co-senior author who led the work on the straight-tusked elephant.
David Reich’s laboratory at Harvard Medical School generated genome-wide data from several ancient mastodon and mammoth genomes using samples prepared at Hofreiter’s laboratory and co-senior author Hendrik Poinar’s ancient DNA laboratory at McMaster University in Canada. Poinar said, “The combined analysis of genome-wide data from all these ancient elephants and mastodons has raised the curtain on elephant population history, revealing complexity that we were simply not aware of before.”
Eleftheria Palkopoulou, a post-doctoral scientist in Reich’s lab at HMS, led the analysis for the study.
The extinct straight-tusked elephants were traditionally grouped with present-day Asian elephants because of morphological similarities in their skulls and teeth. However, a paper published last year by a team led by Hofreiter, including Palkopoulou and Reich, revealed that straight-tusked elephants were on average most closely related to African forest elephants, and not to Asian elephants.
“We were puzzled by the discrepancy between morphological and genetic results, but our analyses show that the ancestry of straight-tusked elephants was highly composite including three ancestral components,” said Palkopoulou. The paper reveals that the extinct giant descends from a mixture of lineages related to an ancient African elephant, the woolly mammoth, and the present-day forest elephant.
“The findings were extremely surprising to us,” said Palkopoulou. “The elephant population relationships could not be explained by simple splits, providing clues for understanding the evolution of these iconic species.” In fact, her analysis of whole elephant-genomes revealed multiple major interbreeding events between different ancient species, highlighting how this played a fundamental role in elephant evolution and raising the question of how widespread major admixture is in other species groups as well.
Future studies will need to explore the diversity of both living and ancient elephants and investigate population structure changes over distance and time.
“Obtaining a technicolor picture of elephant population structure may also be of immediate value for conservation efforts,” said Reich, pointing to work by colleagues showing that with sufficient genetic data black-market tusks can be localized to the regions in Africa from which they were obtained.
Approximately 50,000 elephants are killed each year from poaching, putting many populations in danger. The mastodons and mammoths, who were their close relatives, are gone. Understanding the genetic heritage of elephants has the potential to play a valuable role in future conservation efforts and in preventing these creatures from going extinct.
This article has been republished from materials provided by the Broad Institute. Note: material may have been edited for length and content. For further information, please contact the cited source.
Reference: Palkopoulou, E., Lipson, M., Mallick, S., Nielsen, S., Rohland, N., Baleka, S., … Reich, D. (2018). A comprehensive genomic history of extinct and living elephants. Proceedings of the National Academy of Sciences, 201720554. https://doi.org/10.1073/pnas.1720554115
Synthetic Material That Detects Enzymatic ActivityNews
Scientists integrate protein and polymer building blocks to create stimulus-responsive systemsREAD MORE
Bioethics Council Rules Heritable Genome Editing "Ethically Acceptable" In Certain CircumstancesNews
A leading UK bioethics advisory body has weighed in on the debate around human genetic modification, concluding that heritable genome editing – modifying the DNA of an egg, sperm or embryo with changes that will be passed on to future generations – could be ‘morally permissible’ in humans, provided key ethical tests are met.
Genetic Factors Leading to Rare Bone Fusion Disorder IdentifiedNews
Genome sequencing establishes multiple genes responsible for a rare condition that cause bone fusionREAD MORE | <urn:uuid:910e800f-172f-4084-9478-9cf926d77630> | 4.03125 | 1,506 | News Article | Science & Tech. | 19.570898 | 95,635,980 |
Hydrologic Effects of Global Climate Change on a Large Drained Pine Forest
A simulation study using a watershed scale forest hydrology model (DRAINWAT) was conducted to evaluate potential effects of climate change on the hydrology of a 3,000 ha managed pine forest in coastal North Carolina. The model was first validated with a five-year (1996-2000) data set fro111 the study site and then run with 50-years (1951-00) of historic weather data from Plymouth, NC to determine the long-term hydrology. Later, separate simulations were conducted with 2001-2025 climate change data sets projected by two existing Global Circulation Models (GCM), Canadian Climate Change (CGC1) and the British model (HadCM2). The predicted average annual outflow of 308 mm for the 1996-00 study period (average annual rainfall (AAR) of 1232 mm) was 15% lower than the average of 362 mm for the 1951-00 period (AAR = 1288 min). Simulation results using 2001-25 climate data projected by the CGC1 model yielded a significantly (p<0.0001) lower average outflow (167 mm) compared to 380 mm for the HadCM2. This indicates that the CGC1 model (AAK = 1129 mm) predicted much drier conditions (14% runoff coefficient) and the HadCM2 (AAR = 1358 mm, runoff coefficient = 27%) predicted only 5% higher (p>0.5) outflow than the 50 year historic data showed. Interestingly, the distribution of runoff coefficients for the HadCM2 was almost the same as that for the historic data, indicating minor potential effect of this climate change scenario on drainage. Both the GCM climate scenarios predicted significantly (p<0.005) higher ET than the historic. Water table depth is predicted deeper by the CGC1 model due to lower precipitation input and higher ET. However, the climate changes even under a drier and hotter scenario may not have significantly reduced tree water use although drainage may have been reduced greatly. The ET predicted by the HadCM2 (1008 mm) and CGC1 (1021 mm) were similar, indicating the increase in temperature predicted by the CGC1 model has less of an effect on the soil moisture limiting the tree growth than the increased rainfall predicted by HadCM2.
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- To view this article, download the latest version of Adobe Acrobat Reader. | <urn:uuid:4a795f97-440c-4177-945f-171aed6b0fba> | 2.65625 | 600 | Academic Writing | Science & Tech. | 47.168345 | 95,636,043 |
|Mission type||Balloon-borne telescope|
|Operator||Max Planck Institute for Solar System Research (MPS)|
|Mission duration||6 days (2009), 5 days (2013)|
Max Planck Institute for Solar System Research |
Kiepenheuer Institute for Solar Physics
High Altitude Observatory
Lockheed Martin Solar and Astrophysics Laboratory
Instituto de Astrofísica de Canarias
Instituto Nacional de Técnica Aeroespacial
Instituto de Astrofísica de Andalucía
Grupo de Astronomía y Ciencias del Espacio
|Launch mass||2 t (2.0 long tons; 2.2 short tons)|
|Start of mission|
|Launch date||8 June 2009 and 12 June 2013|
Esrange Space Center|
|End of mission|
|Landing date||14 June 2009 and 17 June 2013|
|Landing site||Nunavut, Canada|
SuFI: 225, 280, 300, 313, 388 nm|
IMaX: 525.06 nm
SUPOS: 854, 853.8 nm
The Sunrise balloon-borne solar observatory consists of a 1m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system and further infrastructure. The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and magnetic fields at a resolution of around 100 km in the quiet Sun.
The strong absorption of UV radiation by the Earth's atmosphere makes it challenging to carry out ground-based observations at these wavelengths. A balloon mission reaching altitudes of above 30 km benefits from a reduction of UV absorption by 99%, making engineering solutions for the telescope easier. The launch site was in the arctic region to make uninterrupted observation of the Sun over several days possible. The telescope has a 1 metre primary mirror that directs the 1 kW of solar radiation to the first focal point where 99% of the radiation is reflected out of the telescope, the remaining light is transferred into several instruments.
The one metre diameter primary mirror is made from a glass ceramic zerodur, it is the central part of the gondola of nearly 2 tons. Solar panels of 1.5 kW output power are used to power the onboard equipment and a hard disk array of 2 x 2.4 Terabyte is used to store the data during flight.
- CWS, Correlating Wavefront Sensor is a CCD camera with 1 kHz read-outs responsible generate the images necessary for image stabilization and proper alignment.
- SUFI, Sunrise Filter Imager observes the sun in five distinct wavelengths 214, 300, 312, 388 and 397 nm, on a 2048 x 2048 pixel CCD, through a filter wheele.
- IMaX, Imaging Magnetograph eXperiment observes the Zeeman splitting of the iron line (FeI) around 525 nm. The observed field of view is 50 x 50 arcseconds.
- Sunrise's first flight was launched at 8:05 8 June 2009 local time from Esrange, near Kiruna, Sweden and it landed 1:45 14 June 2009 local time on Somerset Island, Nunavut, northern Canada after a flight duration nearly six days.
- Sunrise's second flight was launched at 7:38 (5:38 UTC) on 12 June 2013 from Esrange, near Kiruna, Sweden, and it landed afternoon 17 June 2013 on Boothia peninsula, Nunavut, northern Canada after a flight duration of over 5 days.
- "Sunrise - A balloon-borne solar telescope". MPS.
- "Brief instrument overview" (PDF). Sunrise consortium. Retrieved 1 February 2014.
- Sami Solanki. "First results from the Sunrise mission" (PDF). Astronomical Society of the Pacific.
- Barthol, P; Gandorfer, A; Solanki, S; Knolker, M; Pillet, V; Schmidt, W; Title, A (2008). "SUNRISE: High resolution UV/VIS observations of the sun from the stratosphere" (PDF). Advances in Space Research. 42 (1): 70–77. Bibcode:2008AdSpR..42...70T. doi:10.1016/j.asr.2007.09.024.
- Berkefeld, T.; Schmidt, W.; Soltau, D.; Bell, A.; Doerr, H. P.; Feger, B.; Friedlein, R.; Gerber, K.; Heidecke, F.; Kentischer, T.; Lühe, O.; Sigwarth, M.; Wälde, E.; Barthol, P.; Deutsch, W.; Gandorfer, A.; Germerott, D.; Grauf, B.; Meller, R.; Álvarez-Herrero, A.; Knölker, M.; Martínez Pillet, V.; Solanki, S. K.; Title, A. M. (2010). "The Wave-Front Correction System for the Sunrise Balloon-Borne Solar Observatory". Solar Physics. 268: 103. arXiv: . Bibcode:2011SoPh..268..103B. doi:10.1007/s11207-010-9676-3.
- Schmidt, W.; Solanki, S.K.; Barthol, P.; Berkefeld, T.; Gandorfer, A.; Knölker, M.; Martínez Pillet, V.; Schüssler, M.; Title, A. (2010). "SUNRISE - Impressions from a successful science flight". Astronomische Nachrichten. 331 (6): 601. Bibcode:2010AN....331..601S. doi:10.1002/asna.201011383.
"Giant SUNRISE Telescope Successfully Launched". Spaceref. 8 June 2009. Retrieved 1 February 2014.
The giant telescope SUNRISE was launched from Esrange Space Center in northern Sweden. At 08.05 (local time) this morning, the largest balloon born telescope ever took off from Swedish Space Corporation's (SSC) launch facility at Esrange Space Center in northern Sweden.
- "Deutsche Forscher starten Sonnenteleskop "Sunrise"" (in German). Spiegelonline. Retrieved 2009-06-08.
- "Sunrise Science-Blog". MPS.
- "Esrange website". Archived from the original on 21 October 2013.
"SUNRISE, successfully lifted off on June 12". SSC group. Retrieved 1 February 2014.
SUNRISE was successfully launched from Esrange Space Center on June 12, 2013 at 05.38 UTC. | <urn:uuid:2e95c9af-ecab-4967-aaa7-37a7053868bf> | 3.21875 | 1,434 | Knowledge Article | Science & Tech. | 68.967925 | 95,636,096 |
Vicky Meretsky of Indiana University and her co-authors say established state wildlife programs provide "strong building blocks" for such a network. But they make a forceful argument that national cooperation and coordination are needed to protect at-risk wildlife species and habitat and to respond to threats such as novel diseases and climate change.
Amphibians such as frogs are one example cited by the authors. The nation's frog populations have been declining due to the spread of chytrid fungus, particularly in the western U.S. Limited baseline data and state-centered monitoring can obscure range-wide trends for these and other declining species.
"To date, state programs have been inconsistently and incompletely integrated into regional and national networks," they write. "In this era of reduced financing and increased threats, better, more consistent coordination of state-based efforts is increasingly necessary to maximize the effectiveness of limited conservation funds."
Meretsky, associate professor in the School of Public and Environmental Affairs at Indiana University Bloomington, is the lead author of the paper, "A State-Based National Network for Effective Wildlife Conservation." It is available online and scheduled for publication in the November 2012 issue of BioScience.
Co-authors are Lynn A. Maguire of Duke University, Frank W. Davis and David M. Stoms of the University of California at Santa Barbara, J. Michael Scott and Dale D. Goble of the University of Idaho, Dennis Figg of the Missouri Department of Conservation, Brad Griffith of the Alaska Cooperative Fish and Wildlife Research Unit and the University of Alaska, Scott E. Henke of Texas A&M University-Kingsville, Jacqueline Vaughn of Northern Arizona University and Steven L. Yaffee of the University of Michigan.
States have traditionally been responsible for wildlife conservation, although in the 20th century the federal government asserted authority over migratory birds, marine mammals, ocean fisheries and imperiled species. But a state-by-state approach isn't sufficient for protecting ecosystems and habitats that cross state boundaries; and neither does it allow for addressing problems for species that are declining throughout their ranges but not yet endangered or threatened.
While voluntary regional collaborations have had some success, the authors say, they are limited by uneven funding and capacity in different regions and by difficulties in sharing information.
They propose the following goals for a national wildlife conservation network:Establish a common habitat classification map suitable for wildlife conservation.
The article says an effective national network could be built on the basis of state wildlife action plans, or SWAPs, which have been developed through a federal grant program established in 2000. The authors do not recommend a new agency or oversight function, but rather a cooperative and coordinating group that can support and integrate state efforts. They point to NatureServe, a nonprofit supported by state and federal agencies in providing a national species-and-ecosystems database, as a possible model.
BioScience, a publication of the American Institute of Biological Sciences, has presented readers with timely and authoritative overviews of current research in biology since 1964. Research articles are accompanied by essays and discussion sections on education, public policy, history and the conceptual underpinnings of the biological sciences.
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Main Forum Page
The Gyroscope Forum
16 July 2018 23:25
Welcome to the gyroscope forum. If you have a question about gyroscopes in general,
want to know how they work, or what they can be used for then you can leave your question here for others to answer.
You may also be able to help others by answering some of the questions on the site.
||Gyroscopes do not lose weight
A gyroscope attains the ability to resist falling by using the laws of motion.
A traveling mass, whether in a straight line or curving, resist being deflected from its path by the condition of inertia. A mass traveling a distance of 1 foot in one second, while encountering a right angle force will deflected X degrees. Yet, the same mass traveling the same distance of 1 foot, but a thousand times faster, will be deflected only ,1,000/ X degrees. Not much of deflected degree change at all and this is because there was so little time for the applying sideways force to act during each rotation. To belabor the point, if a car is rolling slowly on ice and you push it sideways for one second it should slide a few inches off course; but if you could push the same car sideways for an hour it might slide one mile off its linear course. Comparing the two conditions, in the short duration on one second’s time under sideways fore, the result is hardly any comparative degree of deflection at all.
The mathematical principle is that velocity increases inertia but really, not to be concussed with momentum, it is all about the three mechanical things, resistance x time x distance = the degree of deflection.
When the mass in the rim of a spinning gyroscope curves from horizon to horizon (9: o’clock to 3 o’clock) it is often moving very fast, but for only a very short distance.
Gravity only has an instant to deflect the mass during each single rotation. Per singular rotation, there can be only a very small fall into gravity.
When a gyroscope overhangs a fulcrum the gyroscope is always in the process of twisting as it curves around the fulcrum from an upward slant to a downward slant. As gravity pulls the wheel downward causing the twisting tilt, the inertia in the top of the rotating rim resist deflection from its rotating position, or plain in the same way as a mass traveling in a straight line resist changing its course.
The top rim resists being tilted outward from the fulcrum. The opposite is true at the bottom of the rim. It resists being tilted toward the fulcrum. Top and bottom opposite resistances counter one another.
If you would push your thumb against the top of a none-spinning gyroscope toward the fulcrum, while pulling the bottom of the gyroscope outward from the fulcrum you would twist the shaft down on the fulcrum. This would hold up, or lift the gyroscope by the toque you are applying down on the fulcrum by way of twisting the wheel.
It does not precisely work this way, and this is only a generalize way to perceive a torque acting, and to explain away the incorrect idea that during precession mass weighs less, but of course it does not. The force of gravity is eventually converted into torque by the complex and invisible actions of precession.
Now I will confuse you because I do not know how to avoid it. The deflection from the downward tilting gyroscope does not cause a torque down upon the fulcrum as I suggested. I suggested it for easy of conception and reasoning and not exactitude. The downward torque causes the movement of the wheel around the fulcrum; i.e. precession. In turn, the horizontal circling of precession causes a secondary torque, which is the force that actually applies down upon the fulcrum.
All directional forces in a spinning wheel as it is tilted, will convert into right angle forces. The force of gravity is converted to the right angle precession. The direction of precession is converted into the right angle down upon the fulcrum.
The faster a gyroscope spins the more it resists falling into gravity. This reason is each increment of distance the top has time to twist downward per rotation; the bottom applies a slightly stronger and reverse twisting force upward.
The stronger bottom force guides the direction precession. If there were no friction of any kind whatsoever, this condition of near equal opposing forces would allow a gyroscope to stay aloft for a very long time, but not for too many hours.
The opposing forces not being completely equal is what causes the gyroscope, in a complex and interesting way to continually redirect force in creating the direction of precession. Precession dose not coast. Precession force must be reapplied from millisecond to millisecond, but such a small amount is required to maintain a slow precession that the used-up force dived from the fall of the gyroscope can present an imperceptible fall to the eye.
Precession is very complex, consisting of a number of acting forces all of which are invisible, while busily acting in invisible unison during invisible encounters. There in, is the difficulty in understanding the unintuitive visual conditions.
I find that in order to convey clear and complete understandings of precession, which I have not attempted here, it would be necessary to additionally present animation, drawings or props of some kind. Perhaps I will attempt that in time. For now at least, we can know that recession can occur precisely because the laws of motion are exacting and unalterable. We may know from this explanation at least, how the force of gravity is deflected by inertia into torque, which transfers force of one kind into another kind at a distance.
||15 August 2016
Answers (Ordered by Date)
||Nate - 16/08/2016 22:37:21
| ||Eugene Butikov has an excellent applet program that simulates precesesion and nutation of a gyroscope. You can change parameters and immediately see the effect.|
Also see his papers titled:
Forced precession of a gyroscope
Inertial rotation of a rigid body
Free rotation of an axially symmetrical body
||Glenn Hawkins - 17/08/2016 10:43:18
| ||Hello Nate,|
I hate to be contrary, but it always bothers me that people who do not know what they are doing attempt to explain to people who do know what they are doing.
The sad description you suggest has been non-sense for a hundred years. It presents not one iota of mechanical understanding. It is a lengthy and belabored math formula for physics.
I explained in mechanical terms, ‘why’ a precessing gyroscope does not fall. Later I could attempt an explanation of precisely ‘how’ this is accomplished. So far, no one else has done this.
As to Butikov and others repeating the same semantics and words, if people could actually understand the diagrams and explanations as you suggest, they would then realize it is non-sensible and does not convey an understanding of why gyroscopes do what they do. The word ‘deflection’ explains what, not how and not why. Butikov did not know why a gyroscope does what it does.
By the way, Nate:
Whatever it is that you are doing whirling a something or other in an enclosure, with computer read outs and words over, it is beyond your explanations. Nobody knows what you are doing. I am sorry, but it just suggests you are confused.
||Nate - 17/08/2016 14:19:46
Here’s what Harvey Fiala had to say about explanations:
Answer: Harvey Fiala - 09/09/2004 05:36:10
I wholeheartedly agree with Ram Firestone's answer of October 28, 2003, wherein he disputes Jeremy O'Connor's contention that "The theory needs to be developed along with any physical design". And this applies not only to gyroscopic propulsion, but any type of device that seems to perform in an unusual manner. Some people are gifted with mechanical or practical insights into mechanisms or chemistry or other processes, but yet know nothing about differentials or integrals or relativity or Newton's Laws. It would be seriously wrong to criticize someone who developed a device that worked, but had no idea of how or why it worked. This is where those gifted with a deep understanding of the laws of physics should step forward and attempt to explain how it works instead of "blacklisting" the "inventor" or calling him a crackpot. It takes a team of gifted people to fully develop, understand, and exploit new devices.
It would be just as wrong to criticize those who think they understand the known laws of physics very well for not having invented all the devices that are inventable using those laws of physics. Should we call our top-notch physics and math professors stupid for not being able to invent all inventable devices and solve all math problems? I don't think so.
U.S Patent 2011021983A1
Inertial propulsion device to move an object up and down
Inventor: Harvey Fiala
Disclosed herein are two separate processes that do not require a propellant and do not produce an equal and opposite reaction against any external form of matter in the Local Inertial Reference Frame and do not violate Newton's Laws in the Universal Reference Frame. The first process produces horizontal motion, relies on the earth's gravitational field as an external force, and has been successfully tested. The second process produces vertical motion and relies only on the aether. It has been successfully tested considering the effect of the earth's gravity. Due to the law of conservation of angular momentum, the first process is considered by some to not be possible, but with the proper use of an external field (for example, gravity) and the phenomenon of precession, it is clearly possible. A clear distinction is made between a simple rotor and a gyroscope which is a far more complex device.
||Glenn Hawkins - 17/08/2016 19:52:58
| ||Forgive me Nate, but I am tired and do not have time and inclination to read this non-sense. To me it is very stupid. If anyone wants to read my explanation go for it.|
||Sandy - 21/09/2016 22:23:43
| ||Seems to me that inertial drive is never going to be invented by those who should really know how to.|
Comments were made that the experts should have a crack at the problem of why a device works in spite of the knowledge of the inventor.
Nobody mentioned the fact that they probably cannot provide an answer either, in other words they may just not know, and if accepted principles cannot supply the answers, then what chance has mathematics.
When I finally had my first device perform successfully and repeatedly I decided I had better let Professor Eric Laithwaite see it, as I thought of all people he would be interested.
At this point I remember my son in law Rod asking me why I should take it to him.
I replied that he was the recognised expert in this matter, to which Rod said but you have done it and he hasn’t, which makes you the expert.
I had to explain to Rod that things did not operate in this manner, and that some recognised person would have to endorse my claims, Laithwaite obviously being the most likely
Laithwaite was in raptures with the performance of the machine, however the problem became one of attempting to convince the rest of the world.
Any mention of a device operating in an orthodox manner brought immediate and very often, ill mannered rebuff.
After my successful Australian VIPAC laboratory test and report.
The project team stated that whilst the device was obviously genuine, its operation did not comply with Newton so it could not be developed.
30 years later I am still trying to figure what was meant by that statement.
On return to the UK I took the report to Edinburgh University for their evaluation.
I just wasted petrol going there as the report was declared rubbish and thrown on to a desk whilst still in the envelope, this by a very Ignorant, arrogant, foolish academic person. There are many like this unfortunately.
A professor who I had previously befriended was present at the time.
He said “Now you can see what you are up against, I would like to help you Sandy but I would also like to return to work on Monday”
That said it all.
I ended up doing what all those clever people should have done and got all the answers for myself.
Of course the reasons do not comply with Newton.
No machine can deliver inertial thrust and comply with accepted principles.
However machines can be made to deliver inertial thrust.
In normal circumstances which really do not affect us too much Newton’s law tends to work well enough.
However I would say he stopped a long way short of the end of the task.
Newton was a very clever guy, nobody would dispute that, and for the most part his claims and predictions were accurate. but only up to the point where assumption was traded for fact.
Beyond that point the inventor is on his own, and past that point Newtons laws become detrimental to the advancement of physics, serving only to create an impenetrable stumbling block.
I have had to suffer 30 plus years of this academic brainwashing and stupidity and have just about had it.
The establishment in the meantime will continue to teach the specious junk that is peddled as gospel
Seems like they could be building rocket powered space vehicles for some time yet.
||Sandy - 21/09/2016 23:00:18
| ||Any mention of a device operating in an orthodox manner brought immediate and very often, ill mannered rebuff.|
My apologies guys it should have been unorthodox,
The price of od age?
||Glenn Hawkins - 20/01/2017 00:42:08
| ||Early this morning I finished rewriting a 350 page manuscript. The book was years in the writing and there is not one damn gyroscope in it. I know this does not belong here, but it was such an awful burden to have to finish I wanted to tell somebody. (First drafts are fun. It is the fine, correct and good later tuning that is hard.) I feel different now, really, really different. Everything looks different to my eyes. I am . . . . . . made anew. Somehow.|
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S-Adenosyl-L-methionine—Donor of Methyl Groups
The compound S-adenosyl-L-methionine (AdoMet), shown in Figure 4.1, is the methyl group donor in numerous cellular enzymatic transmethylation reactions, including DNA methylation (Cantoni, 1975). In reality AdoMet is probably second only to ATP in the variety of reactions it serves as a cofactor. When it was first discovered, it appeared to contribute only to the modification of small molecules. However it soon became clear that this is a unique modifying agent, created during evolution to shape the structure of macromolecules as well. Proteins, lipids, polysaccharides, and nucleic acids (RNA and DNA) are all subject to methylation by highly specific enzymes after their primary biosynthesis.
KeywordsMethyl Glyoxal Adenosine Deaminase Transmethylation Reaction Sulfonium Compound Unstimulated Peripheral Blood Mononuclear Cell
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A new study by a University of Exeter researcher has shed light on how an estimated one million-strong population of wild camels thriving in Australia's remote outback have become reviled as pests and culled on a large scale.
Sarah Crowley, of the Environment and Sustainability Institute at the University of Exeter's Penryn Campus, explored the history of the camel in Australia, from their historic role helping to create the country's infrastructure through to their current status as unwelcome "invader."
The deserts of the Australian outback are a notoriously inhospitable environment where few species can survive. But the dromedary camel (Camelus dromedarius) prospers where others perish, eating 80% of native plant species and obtaining much of their water through ingesting this vegetation.
Yet for numerous Australians, particularly ranchers, conservation managers, and increasingly local and national governments, camels are perceived as pests and extreme measures – including shooting them with rifles from helicopters – are being taken to reduce their population.
In her article, published in the journal Anthrozoös, Crowley proposes that today's Australian camels exemplify the idea of "animals out of place" and discusses how they have come to inhabit this precarious position.
She said: "Reports estimate there are upwards of a million free-ranging camels in Australia and predict that this number could double every eight years. As their population burgeons, camels encroach more frequently upon human settlements and agricultural lands, raising their media profile and increasing local animosity toward them."
The camel was first brought to Australia in the 1800s when the country was in the midst of a flurry of colonial activity. The animals were recognized by pioneers as the most appropriate mode of transport for the challenging environment because they require significantly less water, feed on a wider variety of vegetation, and are capable of carrying heavier loads than horses and donkeys.
Camels therefore played a significant role in the establishment of Australia's modern infrastructure, including the laying of the Darwin–Adelaide Overland Telegraph Line and the construction of the Transnational Railway.
Once this infrastructure was in place, however, and motorized transport became increasingly widespread, camels were no longer indispensable. In the early part of the 20th century they rapidly lost their economic value and their displaced handlers either shot their wards or released them into the outback where, quite discreetly, they thrived.
It was not until the 1980s that surveys hinted at the true extent of their numbers, and only in 2001 that reports of damage caused by camels were brought to the general populace.
Camels are not the most dainty of creatures. Dromedaries are on average six feet tall at the shoulder, rendering cattle fencing no particular obstacle to their movement. By some accounts, camels may not even see small fences and consequently walk straight through them.
Groups of camels arriving on agricultural properties and settlements in Australia, normally in times of severe drought, can also cause significant damage in their search for water.
In 2009, a large-scale culling operation began. There were objections from animal welfare groups and some landowners who were concerned that the method of culling from helicopters, leaving the bodies to waste, is inhumane. Most objectors, however, were primarily concerned that culling is economically wasteful and felt that the camels should be mustered for slaughter or export.
There are also concerns regarding the global environment, as camels may contribute to the desertification of the Australian landscape. They are also ruminants and thus produce methane, adding to Australia's carbon emissions. Crowley does not question the accuracy or significance of this, but points out that the environmental impacts of even 1,000,000 feral camels pales in comparison to that of the 28,500,000 cattle currently residing in the country. Still, when dust storms gathered over Sydney in 2009, media reports implied that the camel was the culprit.
Camels have in recent times been referred to in Australia as "humped pests," "a plague," a "real danger" and "menacing," and their actions described as "ravaging" and "marauding."
Crowley added: "These terms show how camels have suddenly been attributed agency – their crossing of acceptable human boundaries is somehow deemed purposeful and rebellious. These accusations lie in stark contrast to the praise laid upon those dromedaries who assisted colonists in the exploration and establishment of modern Australia, and highlight how temporal changes in culture—specifically, shifting economic and environmental values—have affected human interpretations of the presence, purpose, and even behavior of Australian camels."
'Camels out of place and time: the dromedary (Camelus dromedarius) in Australia' by Crowley, S. L. (2014) is published in the journal Anthrozoö. Available here: http://www.ingentaconnect.com/content/bloomsbury/azoos/2014/00000027/00000002/art00003
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Many people have a misguided interpretation of software development. They tend to think most software is generated by solitary individuals beavering away in a darkened room with nothing but the glow of their laptop screens. They spend hours writing lines of code which auto-magically transform into multi-million dollar businesses overnight.
The reality is, that this couldn’t be further from the truth. Software development is very much a team sport and community driven, with each member of the community or team contributing a unique set of skills. However, one important aspect that each member needs to have in common, like with any community , is a common language. Languages are vitally important for communication, they help express ideas and concepts using common expressions and words that are easily understood.
The 6 key elements a common language provide:
- Information flow
- Learning management skills
- Developing Good Human Relations
- Preparing people to accept change
- Ideas encouraged
One of the key factors of success in any software project can be it’s choice of software programming language. The problem is that there is a not one correct language for every conceivable problem. Some problem domains require different approaches, and thought processes that different programming languages facilitate.
The purpose of programming languages are to help software developers
- Comprehend a problem abstractly and to change it using code
- Find ways of tackling problems and using common libraries to help solve them
- Providing the ability to troubleshoot, debug and fix issues
- help to develop solutions quicker and easier
- easy for others to understand
What is Python ?
Python is an open-source , general-purpose, multi-paradigm, high level and interpreted programming language that provides programmers the ability to use various styles of programming to create complex or simple programs, get results faster and write code in as close to human readable language as possible.
Python is the programming language often used to create algorithms for sorting and analyzing chunks of data that businesses and organisations collect globally.
Lets break down what we mean by each of the terms highlighted.
High Level Language
This means code to develop a python program is more like a human readable language that the typical code used to control machines. It makes it easier for programmers to communicate their intention, concepts and ideas to other programmers, because the language is closer to human understandable language.
The human-like language goes through an interpreter that converts it into machine code for machines to understand.
An interpreter is a computer program that directly executes, i.e. performs, instructions written in a programming or scripting language, without requiring them previously to have been compiled into a machine language program.
An interpreter follows strategies for program execution:
- parse the source code and perform its behavior directly;
- translate source code into some efficient intermediate representation and immediately execute this;
- explicitly execute stored pre-compiled code made by a compiler which is part of the interpreter system.
A multi-paradigm programming language is a programming language that supports more than one programming paradigm. The design goal of such languages is to allow programmers to use the best tool for a job, considering that no single paradigm solves all problems in the easiest or most efficient way.
There are a number different programming paradigms including imperative, functional, logic, constraint-based, object-oriented, or aspect-oriented. A paradigm characterizes the style, concepts, and methods of the language for describing situations and processes and for solving problems, and each paradigm serves best for programming in particular application areas.
Python can be used to develop any kind application, whether it be a website, console application, data manipulation , mobile application, games or even complex mathematical and financial calculations.
Open Source is the process of producing a software product with source code freely and openly available to anyone who read or modify. The group of people who do this is called the Open Source community, although it should be noted that there is rarely a single identifiable community that shares exactly the same position on every single aspect of software development and licensing.
Who uses Python ?
Python is used successfully in thousands of real-world business applications around the world, including many large and mission critical systems. There are many stories of organisations initially using Python to program many different complex solutions.
One well noted case, is that of Google, whose initial search engine solution was all first coded in Python! Python’s popularity and versatility continues to grow especially with the advancement of Artificial Intelligence, Big Data and machine learning.
It’s worth reading some quotes on who uses python
Python isn’t always the best tool for the job, but it also isn’t the worst. Many software developers may always first use Python to quickly and easily produce an initial prototype or solution to a problem. Making time and investing in learning Python will no doubt provide opportunities in the future as many Scientists, Mathematicians, Marketers, Information Technology, Financial, business people, teachers, governments and even religious organisations all use python as their de-facto programming language.
A unique background as business owner, marketing, software development and business development ensures that he can offer the optimum business consultancy services across a wide spectrum of business challenges.
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- Why We Buy – The science of shopping - May 15, 2018 | <urn:uuid:42729938-e452-4ffa-939a-001d22dfd8e1> | 3.421875 | 1,112 | Personal Blog | Software Dev. | 18.190008 | 95,636,202 |
PHP is a server-side scripting language that is most often used for web development. However it is also used as a general-purpose programming language.
Ranked in these QuestionsQuestion Ranking
Pro One of the most common languages
According to the 2015 Stack Overflow Developer Survey (26,086 people surveyed), PHP was the 5th most popular/used language at 29.7%.
Pro Lots of tutorials online
Pro Used by most common CMS platforms
Many clients are looking for an easy-to-update web site that's flexible and free. Drupal and Wordpress fill those needs very well.
Pro Most prominent language for web applications
Part of the de facto standard web application stack.
Pro Great third-party package manager
PHP standard library is somewhat subpar, but if you need plugins, language features, composer has them all( you can even puzzle together a custom framework from composer).
Since 7.x was released, PHP has become a pretty fast language.
Pro Lots of PHP frameworks available which help with development
PHP people love frameworks, and with frameworks such as Laravel, you can build a web app or API really fast (Facades, ORMs, scaffolding etc.)
Pro Great documentation
Con Poorly designed language
Despite its widespread use, PHP is generally looked upon poorly from a design point of view. The consistency of function names and function argument order, lazily and borderline non-functional implementation of object oriented programming, can only receive requests via POST methods, slow version adoption (the PHP you learn right now may not work on every webserver you'll work on), and a focus on "hacking things together" rather than "doing it right". These are all very common complaints when it comes to working with PHP. While not a bad language to learn, PHP is not at all a good language to learn first, as it will probably teach bad habits.
Con Most tutorials are out of date
A lot of very bad tutorials are still widely circulated among beginners, and these tutorials teach very poor programming practices.
Con Immense catalog of insecure frameworks
The most serious security problems in websites on the web today are almost universally found in popular PHP frameworks, CMS platforms, libraries and code samples, almost all stemming from poor language design, bad tutorials and awful resources.
Con Most resources are poorly-written
Few resources exemplify the "correct" or secure use of features. | <urn:uuid:7e889e1b-1943-449b-bcd3-28d8bdd9d96a> | 2.71875 | 494 | Knowledge Article | Software Dev. | 41.582273 | 95,636,204 |
Chapter 4. Notation and Conventions
Table of Contents
Since there are many supported target architectures, notation conventions are used in this manual to avoid repeating instructions that are very similar.
4.1. GDB and GCC Command Notation
Cross-development commands like gcc
and gdb will be shown with a
TARGET- prefix. You need to replace
TARGET- with the correct prefix before
using the command. Just using gcc
or gdb will use the tools for the
host, which is not (usually) what you want.
For example use arm-eabi-gcc and arm-eabi-gdb for ARM7, ARM9, Thumb, Cortex-A, and Cortex-M targets. Use powerpc- eabi-gcc and powerpc-eabi- gdb for PowerPC targets. Use i386 -elf-gcc and i386-elf-gdb for IA32 targets. And so on, the exact prefix to use is shown in the documentation for each target.
Note that some versions of the GCC cross compiler generate executable
files with the
.exe suffix on
Windows, but not on Linux. The suffix
.exe will be omitted from executable file
names, so you will see
4.2. Directory and File System Conventions
The default directory for eCosPro distributions on Windows (usually
C:\eCosPro) is different from
that on Linux (usually
$HOME/ecospro for non-root installations).
Since many command line examples in the tutorials use these paths,
this default (base) directory will be cited as
Windows and Linux have a similar file system syntax, but the MS-DOS command interpreter on Windows versions prior to Windows 10 uses the backslash character (\) as a path separator, while Linux and POSIX shells (including the bash shell for windows) use the forward slash (/). Windows 10 can use both characters.
This document will use the POSIX shell convention of forward slashes throughout.
4.3. Version Conventions
This manual does not refer explicitly to any particular distribution
of eCos or eCosPro. However, version numbers form part of many
file path names. In all of these places the version number will be
shown like this:
If you are using the freely available public distribution of
eCos at http://hg-pub.ecoscentric.com/ and have used
Mercurial to check
eCos out of the repository, the version
number will always be
current, since that is the
name of the directory in the repository. When a stable release is made
this directory name is changed, in the release, to the number of the
release, for example
|2018-07-06||Open Publication License| | <urn:uuid:d335b163-1fb6-4be2-895d-f59f3a432a9d> | 3.1875 | 585 | Documentation | Software Dev. | 53.116667 | 95,636,221 |
Java database connectivity (JDBC) is the Java Soft
specification of the API. It allows Application Programs to interact with the Database to access the Relational Data. Typically the JDBC API consists of a set of interfaces and classes written in the Java programming language. The applications can be written to connect to databases using these standard interfaces and classes and also to process the results by sending queries written in SQL. Furthermore the back-end Database session can be connected by JDBC API which can execute the Queries to get the Results.
Some of the new set of features which come along with Mustang is JDBC 4.0 are:
No need for Class.forName("DriverName")
Changes in Connection and Statement Interface
Using ResultSet Becomes More Flexible
More APIs Become Available
The three most important features of Driver and Connection Management in JDBC are described below with some new features and enhancements.
1. Getting Connected Becomes Easier
This is one of the most important feature in JDBC that has relieved the developers from loading the driver explicitly. Exactly, you got it right, no need to explicitly load the driver by calling Class.forName anymore. So from now on don't bother to load the driver because the DriverManager will automatically load the driver found in the application CLASSPATH while your application tries to connect the database for the first time. However it is still preferred to create an appropriate DataSource object to retrieve a connection. Since the properties of data source instance can be modified which allows portability and transparency, there is no need to modify any application code to connect to a different database instance. Hence to retrieve a connection there is no need to change any application code to connect to a different database instance that requires loading a different driver.
For example: Earlier the programmers used to
manually load the drivers before making any Database Calls. The code which was
used by the programmers is:
The disadvantage is that the code will be changed if the Database Driver vendor wants to change the class name. Now this problem doesn't persist anymore. With the help of Service Provider Mechanism available from Java 5, the Driver will be Loaded Automatically by the JVM provided that the Jar files corresponding to the Driver Class are in the appropriate class path.
To understand this mechanism consider two entities, one is the service which contains a set of interfaces and the other entity is the provider who gives a well-defined Implementation for the Service. Now to maintain a directory structure, this service is packaged as a Jar by the provider. The structure of a directory is:
After maintaining the directory structure, if the JDBC Driver Provider wants to make his implementation as a Service then he has to maintain the file name along with the directory structure as,
Rememeber the file should only contain one entry that is the Name of the Provider Class. The function of this entry is to implement the Driver. Also the name of the file is java.sql.Driver in the above code. For instance the content of the file in My SQL would be,
File - Java.sql.Driver
com.mysql.jdbc.Driver # Class name of the Driver
Hence any Java program will automatically load the JDBC driver by the procedure. Moreover if the application class-path contains multiple drivers then the preference will be given to the first matching driver only ignoring the rest of the drivers.
2. Using ResultSet Becomes More Flexible
Several important features of ResultSet interfaces hierarchy are described below:
The ResultSet provided by the RowSet sub-interface is scrollable, updateable, and offline-editable . The JDBC programming has become much more easier and flexible due to the current version's support for the SQLXML data type along with these features.
Another feature of the ResultSet is the WebRowSet sub-interface. This interface provides the ability to read data from database tables. Moreover it is used to serialize the data to an XML document, and deserialize from XML back to result set. | <urn:uuid:7d6d4e8a-d2cc-4e05-b3a9-2a5d19a3a794> | 2.859375 | 825 | Documentation | Software Dev. | 36.851914 | 95,636,245 |
Researchers at the University of Basel have developed a live-cell fluorescent labeling that makes bacterial cell-to-cell communication pathways visible. The communication between bacterial cells is essential in the regulation of processes within bacterial populations, such as biofilm development. The results have been published in the journal Chemistry – A European Journal.
Most bacteria are able to communicate with each other by secreting signaling molecules. Once the concentration of signals has reached a critical density («the Quorum), the bacteria are able to coordinate their behavior. Only when this critical population density has been reached certain genes are activated that lead to, for example, the formation of biofilms or the expression of virulence factors. Bacteria utilize this so-called «Quorum Sensing» (QS) to synchronize their behavior to regulate functions that benefit the entire population.
The most commonly used signaling molecules are N-Acyl-L-homoserine lactones (AHLs) that are secreted by the bacteria into their surroundings, where they can easily be incorporated by other cells. The AHLs then start binding to specific QS-receptors once a certain density has been reached inside the cell.
Fluorescent labeling of signaling compound to visualize receptors
The research groups under the leadership of Prof. Karl Gademann (University of Basel) and Prof. Leo Eberl (University of Zurich) have succeeded in visualizing live cell-to-cell communication pathways. The scientists added fluorescents tags to natural AHL signaling molecules and were able to show through tests with bacterial cultures that the modified signaling molecule selectively binds to the Burkholderia cenocepacia QS receptor.
B. cenocepacia is a member of a bacterial group known to form biofilms in the lungs of immunocompromised persons or patients suffering from cystic fibrosis, causing severe complications such as pneumonia.
The scientists were also able to detect the receptor in a native population of B. cenocepacia. Here, the natural AHL signaling molecule is competing with its artificial analogue for the binding to the receptor. The fluorescent-labeling agent was equally distributed over the live cell, which made it possible to localize the receptor inside the cytoplasm for the first time.
Broad application possibilities
Using fluorescently labeled AHL analogues represent an operationally simple tool for the imaging of QS receptors in live cells. Thus, this new method could be used for a broad range of applications, such as the fast analysis of QS in various environmental and clinical samples. Furthermore, it might lead to a better understanding of the communication between bacteria and host as well as of the cell-to-cell communication in bacteria populations.
Original Citation: José Gomes, Natalie Huber, Alexander Grunau, Leo Eberl, Karl Gademann Fluorescent Labeling Agents for Quorum-Sensing Receptors (FLAQS) in Live Cells Chem. Eur. J. 2013, 19, published online 13 Jun 2013 | doi: 10.1002/chem.201301387 | <urn:uuid:8ca00090-112c-4b05-933b-661d3b3a1255> | 3.03125 | 632 | News Article | Science & Tech. | 24.066275 | 95,636,249 |
- Open Access
Adding structure to land cover – using fractional cover to study animal habitat use
© Bevanda et al.; licensee BioMed Central. 2015
Received: 10 June 2014
Accepted: 11 December 2014
Published: 25 December 2014
Linking animal movements to landscape features is critical to identify factors that shape the spatial behaviour of animals. Habitat selection is led by behavioural decisions and is shaped by the environment, therefore the landscape is crucial for the analysis. Land cover classification based on ground survey and remote sensing data sets are an established approach to define landscapes for habitat selection analysis.
We investigate an approach for analysing habitat use using continuous land cover information and spatial metrics. This approach uses a continuous representation of the landscape using percentage cover of a chosen land cover type instead of discrete classes. This approach, fractional cover, captures spatial heterogeneity within classes and is therefore capable to provide a more distinct representation of the landscape. The variation in home range sizes is analysed using fractional cover and spatial metrics in conjunction with mixed effect models on red deer position data in the Bohemian Forest, compared over multiple spatio–temporal scales.
We analysed forest fractional cover and a texture metric within each home range showing that variance of fractional cover values and texture explain much of variation in home range sizes. The results show a hump–shaped relationship, leading to smaller home ranges when forest fractional cover is very homogeneous or highly heterogeneous, while intermediate stages lead to larger home ranges.
The application of continuous land cover information in conjunction with spatial metrics proved to be valuable for the explanation of home-range sizes of red deer.
Habitat use of animals is assumed to be mainly driven by forage availability and is a complex hierarchical process of behavioural responses and choices . Individuals choose habitat that maximizes resources (e.g. food or shelter) and conditions necessary for survival and reproduction , whereas these resources are influenced by temporal and spatial variations of the landscape . Habitat selection is led by behavioural decisions and is shaped by the environment, leading to the observed habitat use .
A large majority of animals use certain areas without showing a territorial behaviour, referred to as home range. In contrast to territories, a home range has no defended borders . Home ranges are generally defined as the spatial expression of all behaviours an animal performs in order to survive and reproduce . Since home ranges link individual movement paths to dispersal and population dynamics, understanding why and how home range sizes vary between and among species is a fundamental issue in ecology. The current and prospective availability of large movement data sets and remotely sensed environmental information will allow further detailed analysis . Progress in GPS–sensor receiver technology and satellite telemetry makes it possible to track animals over long time spans with high temporal and spatial resolution and to analyse their habitat requirements and movement paths .
By studying variation in home range size and identifying the factors involved in such variation, we can identify how habitat influence individual’s habitat use and therefore the variation in home ranges. A number of factors have been adressed for shaping variation in home range sizes, these include the environmental productivity and the heterogeneity of the landscape [8-10]. Especially the availability of forage is a main driver shaping home range sizes . A common trade–off often faced by many large mammals takes places when open habitats provide the best forage, while closed habitats provide shelter against predators and this may vary with different spatio–temporal scales .
Typically in habitat use studies the landscape is represented with a categorical habitat map usually derived from a classification [13,14], while in other studies the landscape is represented only by the dominant habitat type [15,16]. A variety of land cover classifications are routinely produced using remotely sensed data such as MODIS and AVHRR .
However, the way the landscape is defined is crucial for the analysis of habitat use. In many studies the landscape is defined in land cover categories, containing classes such as “meadows”, “forest” and “agriculture” [13,15] and it is common sense that different needs of an animal corresponds to different land cover types, for example “forest” as areas for shelter and therefore resting or hiding sites, and “meadows” as areas for forage sites .
However, landscapes rarely contain sharp borders between cover types although that is how they are portrayed using a classical land cover classification approach. Moreover information about spatial variation within an a–priori defined land cover class is not provided when using a classification. A forest might vary spatially due to different age classes of the trees or small tree fall gaps which increase spatial heterogeneity. This within land cover variation is not captured by categorical maps.
Therefore we use a continuous land cover approach such as fractional cover for the inclusion of spatial variation within classes for our analyses. Fractional cover is a multiscale analysis combined with spatial prediction. This method is related to spectral unmixing methods . The fractional cover image are typically created using a higher resolution land cover classification image to calculate fractional cover training data for lower resolution imagery. For each pixel of the coarse resolution image the percentage coverage for each land cover class within the high resolution is calculated and used for a spatial prediction of the land cover percentages. The percentage cover for the chosen land cover types per pixel of the coarse resolution image is provided as result.
With this approach a continuous land cover classification can be derived which captures the spatial structure in a fine scale manner and this provides a more realistic and more ecologically meaningful representation of the landscape. Global maps with similar approaches of percentage coverage already exist such as MODIS or AVHRR [19,20] however only at a coarse spatial resolution and not validated in the study area.
Furthermore in many habitat use studies forests have structural attributes like “dense forest” or “light forest” with corresponding functional effects, such as light forest with plentiful food resources due to an established understory as enough sunlight can reach the forest floor. However, these structural attributes are often not validated and instead they are implicitly assumed . With the fractional cover approach these structural attributes can be addressed clearly.
In this study, we investigate the potential of continuous land cover information for habitat use of red deer in the Bohemian Forest. As habitat use leads to differing home range sizes, we investigate the potential of continuous land cover information and its spatial representation for the explanation of their variation in size. We hypothesize larger home ranges with increasing forest cover due to lower density of food resources. We test our hypothesis on different spatial (90%, 70% and 50% isopleths) and temporal scales (monthly, biweekly and weekly) to account for temporal and spatial differences.
The study area is located in Central Europe in the Bohemian Forest, an area belonging to two national parks: the Bavarian Forest National Park on the German side of the border (240 km 2) and the Šumava National Park on the Czech Republic side of the border (640 km 2). These protected areas are embedded within the Bavarian Forest Nature Park (3070 km 2) and the Šumava Landscape Protection Area (1000 km 2). In its entirety, the area is known as the Bohemian Forest Ecosystem. The area is mountainous, with a variation in elevation between 600 and 1450 m.a.s.l.. The mean annual temperature varies between 3°C and 6.5°C along higher elevation and ridges. The mean annual precipitation is between 830 and 2230 mm. Within the park, three major forest types exists: above 1100 m: sub–alpine spruce forests with Norway Spruce (Picea abies L.) and some Mountain Ash (Sorbus aucuparia L.), on the slopes, between 600 and 1100 m elevation, are mixed montane forests with Norway Spruce, White Fir (Abies alba MILL.), European Beech (Fagus sylvatica L.), and Sycamore Maple (Acer pseudoplatanus L.). In the valley bottoms, spruce forests with Norway Spruce, Mountain Ash, and birches (Betula pendula ROTH. and Betula pubescens EHRH.) . Since the mid–1990s, the forests of the national park have been affected by massive proliferation of the spruce bark beetle (Ips typographus). By 2007, this had resulted in the death of mature spruce stands over an area amounting to 5,600 ha [23,24].
Red deer data
From 2002–2011 red deer were caught during winter, using a procedure approved by the Government of Upper Bavaria, Germany. Red deer were captured and fitted with GPS collars (Vectronic Aerospace, Berlin, Germany) in box traps with side windows after they were lured in with food. Here no immobilization was necessary. A second approach was to tranquillize deer by dart gun where they were attracted by food . We collared 80 deer (39 male, 41 female). Ten individuals were collared two or more times. As animals spend the winter in enclosures, we restricted the analysis temporally from May to the end of September. The most common protocol was to mark red deer in late winter and retrieve the collars after a year by collar drop–off or recapturing, allowing the collars to be used on new individuals. We removed spatial and temporal false fixes (i.e. locations taken only a few seconds apart) beforehand. We defined the samples from the multiple collared animals over the single year as independent. As the schedule of the collars are adjusted to take a location every 15 min for one day of the week we took a random sample of animals with sequences of short time intervals to ensure that all locations have a minimum interval of one hour. The median accuracy of the GPS locations was 16.5 m .
Home range estimation
Home ranges were estimated with a commonly used approach, the fixed kernel method [27,28] using the reference method for the smoothing factor h . We used three different home range definitions to include a spatial scale and to investigate the effect on the core area (50% kernel) and a wider range (70% kernel, 90% kernel). In addition, all home range definitions were estimated on three temporal scales: monthly, biweekly and weekly. We only estimated home ranges for individuals with at least ten locations for a given temporal scale, after removing spatial and temporal outliers .
Representation of the landscape
We extracted all fractional cover values of the forest class within the home ranges and calculated mean, standard deviation and variance. In addition to fractional cover we chose to also calculate texture measures for each home range. Texture metrics were developed by Haralick et al. (1973) and capture habitat structure which can be quantified using the variability of pixel values in a given area. Second–order texture measures are calculated from the gray–level co–occurrence matrix (GLCM) and account for spatial arrangement of pixel values. Haralick et al. (1973) presented a variety of different texture metrics, however he states that these metrics are highly correlated and can be difficult to interpret. To ensure that the chosen texture metric is not size dependent we calculated buffers from 500 to 7000 m in 500 m steps around the home range centres of the 90% kernel isopleths and analysed all texture metrics with regard to their size dependency. We calculated texture measures using all pixel values within the home range. A moving window was used to calculate the texture metric for every pixel relative to its direct neighbours (eight pixels around a centre pixel). We then averaged the resulting texture values to obtain one value for the home range to fit into the mixed model design. We chose to use the texture metric “contrast”, as it shows the least size dependency (see Additional file 1: Figure S1 and is easy to interpret as a measure of local variation in the image and therefore an indicator of landscape heterogeneity. Throughout the remaining text we will refer to the contrast metric as a texture metric or simply as texture.
We choose to use standard deviation of the forest fractional cover calculated within a home range as a measure for variability and the mean forest fractional cover as an estimate of overall forest fractional cover within each home range. Since variables standard deviation and variance show high collinearity , variance is not considered in the analysis. For simplicity we will refer to the standard deviation as variation of fractional cover values.
Furthermore we estimated the mean elevation of the home ranges using the 30 m ASTER Global Digital Elevation Map (GDEM) (http://asterweb.jpl.nasa.gov/gdem.asp).
The chosen variables showed no correlation with each other (Pearson’s correlation with the threshold set to 0.7, -0.7 respectively).
To investigate the influence of forest fractional cover and texture on home range sizes, we used linear mixed models on the log transformed home range areas (km 2). Afterwards we ran a backfit on the t–values to derive the essential variables . Preliminary analysis showed that the variables texture and elevation have a hump–shaped relationship with home range size in the red deer data and we therefore used a quadratic fit in the models.
Following the framework of Zuur et al. (2009) for mixed effect models, we first identified the best structure for the random effect term. We fitted random intercepts for each individual (ID), different sexes and the year the locations were sampled, using the full model with respect to fixed effects terms and using the REML criterion for fitting. We started with the full random term and then simplified the model. Afterwards we compared the models with an ANOVA and the best model was evaluated with the Akaike Information Criterion (AIC). For variable selection, models were fitted with a maximum likelihood criterion. We considered as fixed effects the mean value of the fractional cover layer forest within a home range, the standard deviation of fractional cover values within a home range, the texture metric contrast and elevation. The final models where fitted using the REML criterion. We derived minimal adequate models by backward stepwise selection using a t–value of 2 as a threshold for inclusion . We repeated the analysis for the three definitions of home range size and for the three definitions of temporal scale.
We used the software tool R version 3.0.1 for all analysis. The package “adehabitatHR” was used for the kernel calculations, “raster” , “EBImage” and “randomForest” for creation of the environmental variables and “lmer” and “LMERConvenienceFunctions” were used for the statistical analyses.
Home ranges of red deer show a high variation in size in our study area (Additional file 1: Table S1). We analysed the variation of home range sizes with a mixed model, using mean and standard deviation of the forest fractional cover, as well as the variable elevation and a texture metric. The main random effect in all models was the individual effect (variable ID) with an explained deviance of 0.26–0.38% (Additional file 1: Table S3). The fixed effects of the most parsimonious models explained between 26.88% and 30.88% of the observed variation in home range size for red deer across the different spatio–temporal scales (Additional file 1: Table S2).
In all models the texture metric showed the highest explained deviance (7.98%–14.72%) across scales and was the dominant variable explaining variation in home range size with a hump–shaped relationship (Figure S3, Additional file 1: Table S2). However, this hump–shaped relationship was only pronounced at the monthly time scale, whereas in the biweekly and weekly time scale this relationship changed to a negative linear relationship. The texture metric can be interpreted as an index for spatial heterogeneity in a given area. Hence, at larger temporal scales very homogeneous and very heterogeneous landscapes are leading to small home ranges, while at smaller temporal scales only very heterogeneous landscapes lead to small home ranges.
Additionally mean showed a positive effect (5.48–7.12% explained deviance), with no effect on the monthly time scale kernel 50% isopleth (Additional file 1: Figure S2A).
Elevation had a hump–shaped effect on home range size and showed a low explanatory value of 0.35%–6.02% (Additional file 1: Figure S2B).
Many studies of habitat use and home range variation consider the landscape as a categorical map with defined and clearly separated patches [13,14]. This study investigates the use of continuous land cover information, fractional cover, to analyse the within land cover class variation of home ranges over different spatial and temporal scales for red deer in the Bohemian Forest. We demonstrate that small scale variations represented by continuous landscape data provide important information for modelling habitat use.
Red deer as a mixed feeder has the ability to digest a broad spectrum of food items and benefits from forest edges and from the food supply of younger forest stands which show a low forest canopy cover and therefore have a pronounced understory, as sunlight can reach the ground. Mean forest fractional cover shows a positive relationship with home range size meaning that a higher proportion of dense forest will lead to larger home ranges. Whereas in forest patches with less crown cover and therefore more heterogeneous structure, food resources are more abundant which leads to smaller home ranges. This result is in support with other studies [14,45,46]. Mean forest fractional cover is a rather unsuitable derivative, as it averages all pixels within the home range. Nevertheless it shows a significant explanatory value and gives an overview of the overall forest structure within the home range.
The standard deviation of forest fractional cover values captures the variability of values within a home range. High values indicate a wide spectrum of forest fractional cover and therefore a more heterogeneous landscape while small values indicate a more homogeneous landscape within the home range. Tufto et al. (1996) have shown, that female roe deer adjust the size of their home range in response to food supply. In accordance to this study red deer home range sizes increase in our study area with increasing standard deviation and therefore with more heterogeneous forest fractional cover, leading to a higher amount of unfavourable forest habitat within the home range.
The explanatory deviance is largest for the texture metric and also consistent over all spatio–temporal scales with a hump–shaped relationship at larger time scales. Low values of the texture metric correspond to high heterogeneity within the home range, while high values of the texture metric correspond to landscapes which have large aggregated patches. This relationship was detected in a previous study and can be explained by the characteristics of the National Parks. Bark beetle outbreaks in the 90ies affected an area of approximately 5,600 ha especially in the subalpine regions, leading to sunny openings and large regeneration areas characterized by high grass cover, lying dead wood and regrowing vegetation . These areas appear very homogeneous when calculated with a texture metric but offer good habitat for deer, as different resources are provided in a small area, leading to small home ranges, as both requirements, food and cover, are fulfilled at the same spot. Furthermore a heterogeneous landscape, providing many different resources, leads to small home ranges as all the resources needed can be reached within a small distance. The hump–shaped effect flattens in the biweekly and weekly time scale and can only be described with a negative linear trend. However, a pattern towards a hump–shaped distribution can be seen (Figure 3B). This result shows that the temporal scale needs to be accounted for when analysing home ranges as they are likely to change not based on ecological patterns only but on the time scale of the study. The time period of the study is restricted to the summer months, therefore the resource cover can be regarded as static, i.e. not highly changing over the time, while the resource food is dynamic and depleting. Therefore food supply is the main force shaping home range size during summer. When large patches of dense forest occur within the home range, the texture value will increase. These areas provide shelter against predators, but provide only little food resources. Therefore, as food resources are regarded to be a main force shaping home range size, home ranges will increase in size with the inclusion of large patches of dense forest (intermediate values of texture). Furthermore, these regeneration areas are located at higher altitude and are therefore explaining the effect of elevation, reflecting the importance of bark beetle areas in this study. Like the regeneration areas, elevation shows a hump–shaped fit leading to smaller home ranges where important resources are abundant .
It is known that other factors, like body mass, age, reproductive status or climatic parameters like temperature or rainfall have an effect on home range size (please see for a more complete list) and it is likely, that by including these parameters, the explanatory value of the models could be increased. However, the best method to estimate home ranges is under debate. While we used at least 10 relocation points to estimate our home ranges other studies suggest at least 20 relocation points .
The choice of environmental parameters is important for habitat use modelling. Using classified land cover requires clear definitions of the land cover types but definitions often vary between different maps making them difficult to compare . Moreover do these classes need to reflect the ecological requirements. An increased discrimination of different land cover types is often helpful to better describe a landscape but an increase in the number of land cover classes often results in lower per–class accuracy. Using alternative information such as continuous cover can help to improve how a landscape is represented in a model. Applying remote sensing time–series data can be valuable to further discriminate land cover types and hence allow more fractional cover classes if distinct temporal signature exist for the different targeted land cover types. Applying continuous land cover information for environmental analysis provides detailed information about ecotones and within land cover variation. This research illustrates that fractional cover mapping has potential benefits for ecological research by avoiding categorical values or sharp, most often artificial, boundaries in the landscape. However, the fractional cover approach requires more analytical steps including spatial prediction models and might therefore be potentially biased by the model used.
The study demonstrates that continuous land cover information can provide valuable information about spatial within class variation as well as gradual vegetation changes, a feature that is not available when using discrete classes. This is especially relevant in movement ecology where a continuous representation of the landscape might be more ecological appropriate. However, to evaluate the added value of the fractional cover approach with regard to land cover classification or biophysical parameter further analysis are needed. Fractional cover mapping of different land cover types adds information, critical to ecological studies, beyond what traditional land cover categorical mapping can offer. As the synergy between remote sensing and ecology increases improved processing and analysis methods will continue to be developed which will have a positive impact on ecological research. These benefits will be especially important with the growing interest in spatio–temporal movement pattern.
This work was financed by the German Federal Environmental Foundation (Deutsche Bundesstiftung Umwelt), the EU-programme INETRREG IV (EFRE Ziel 3), and the Bavarian Forest National Park Administration. We kindly thank Ingo Brauer, Horst Burghart, Rüdiger Fischer, Martin Gahbauer, Helmut Penn, Michael Penn, and Lothar Ertl for technical support. We thank the anonymous reviewers for valuable comments which improved the manuscript considerably.
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This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. | <urn:uuid:29c4d824-9e14-4bb3-a7ed-7f475b688246> | 3.09375 | 7,717 | Academic Writing | Science & Tech. | 35.221677 | 95,636,252 |
Though 75% of the planet is a comparatively unchanging ocean of blue, the remaining 25% of Earth’s floor is a dynamic inexperienced. NASA/NOAA Suomi NPP satellite tv for pc is ready to detect these delicate variations in greenness. These sources spotlight our ever-changing planet, utilizing extremely detailed vegetation index information from the satellite tv for pc, developed by scientists at NOAA.
The darkest inexperienced areas are the lushest in vegetation, whereas the pale colours are areas sparse in vegetation coverd both with snow, rock, effected by drought or city areas. Satellite tv for pc information from April 2012 to April 2013 was used to generate unimaginable animations and pictures.
Vegetation modifications are seen to subtlety alter over one yr in movies beneath, utilizing vegetation index information from the NASA/NOAA Suomi NPP satellite tv for pc.
Satellites observe global-scale patterns of vegetation that scientists use to check modifications in plant development because of local weather and environmental modifications in addition to human exercise. Photosynthesis performs an enormous function in eradicating carbon dioxide from the environment and storing it in wooden and soils, so mapping vegetation is a key a part of finding out the carbon cycle. Farmers and useful resource managers additionally use satellite-based vegetation maps to assist them monitor the well being of our forests and croplands.
Amidst the deserts of Egypt, the Nile River supplies life-sustaining water to the area. Additionally seen are the urbanized areas of northern Egypt.(Credit score: NASA/NOAA)
Moisture from the Caspian Sea precipitates on the northern fringe of the Elburz Mountains, and on the southern edge, deserts emerge within the rain shadow.(Credit score: NASA/NOAA)
The “river of grass” extending south of Lake Okeechobee reveals clear indicators of its modified state with areas of dense agriculture, city sprawl and water conservation areas delineated by a sequence of waterways that crisscross Southern Florida. (Credit score: NASA/NOAA)
You’ll be able to view, obtain, or analyze extra of this information from NASA Earth Observations (NEO): Vegetation
Featured picture: Inexperienced vegetation index – Flat Earth (Credit score: NASA/NOAA) | <urn:uuid:3bc5330e-f67b-407a-8fbf-de9840e78243> | 3.15625 | 468 | Knowledge Article | Science & Tech. | 16.255641 | 95,636,260 |
There's really only one string operator, and that's the concatenation operator . (dot).
This operator takes two string values, and joins the right-hand string onto the left-hand one to make a longer string.
<?php echo "a, " . "b"; // Displays "a, b" ?>/*from ww w . j a v a2 s.c o m*/
You can concatenate more than two strings at once.
The values you concatenate don't have to be strings.
Due to PHP's automatic type conversion, non-string values, such as integers and floats, are converted to strings at the time they're concatenated:
Code: <?php $tempF = 1; echo "this is " . ( (5/9) * ($tempF-32) ) . " degrees C."; ?>
You can use the combined assignment operator .= to join a new string onto the end of an existing string variable.
For example, the following two lines of code both do the same thing.
They change the string variable $x by adding the string variable $y to the end of it:
$x = $x . $y; $x .= $y; | <urn:uuid:60bca1f0-9626-4b1e-9c12-16741dbd0b32> | 3.265625 | 264 | Documentation | Software Dev. | 84.251464 | 95,636,287 |
More extreme weather to come: WMO
Scientists believe the North and South Poles are the "canaries in the coal mine" when it comes to understanding the world's rapidly changing climate system.
The poles are key because they harbour the Earth's frozen water supplies known as the "cryospheres".
One scientist who says we need to look to the Poles for clues as to what will happen next in terms of climate change is Dr David Grimes — he's the President of the World Meteorological Organisation.
The global climate chief says recent record heat waves, forest fires and flash flooding are signs that the Earth's climate system has entered a new meteorological era — and he predicts that there'll be more extremes to come.
Dr. Grimes is in Melbourne for a two-day climate forum, where he'll will deliver the opening remarks this morning.
- Dr. David Grimes
- President of the World Meteorological Organisation
- Julie Street | <urn:uuid:d2dfaa63-66ac-47d2-bbed-a7d864fbc392> | 2.703125 | 191 | News Article | Science & Tech. | 46.662357 | 95,636,297 |
- Item 11: Define a copy constructor and an assignment operator for classes with dynamically allocated memory.
- Item 12: Prefer initialization to assignment in constructors.
- Item 14: Make destructors virtual in base classes.
- Item 15: Have “operator=” return a reference to *this.
- Item 23: Don’t try to return a reference when you must return an object.
And the following style guidelines from Scott Meyers’ “More Effective C++” book:
- Item 6: Distinguish between prefix and postfix forms of increment and decrement operators.
- Item 7: Never overload “&&”, “||”, or “,”.
When selecting this option, be aware that the standard library headers do not obey all of these guidelines; use grep -v to filter out those warnings. | <urn:uuid:8c415d57-1f4a-474c-920d-b66730513aea> | 2.796875 | 187 | Listicle | Software Dev. | 40.042857 | 95,636,299 |
The Leibniz Association has awarded a grant of almost one million euros to a research project on mangroves, which will collect data in tropical regions around the globe. The project makes use of state-of-the-art molecular biological methods, which will be used for the first time in this combination to study the mangrove ecosystem. The large-scale, three-year project is coordinated by the Leibniz Centre for Tropical Marine Research (ZMT).
The objective of the project is to understand how the services of mangrove forests for humans and the environment are related to the condition and change in their flora and fauna. Using state-of-the-art molecular biological methods, such as metabarcoding and metagenomics, the species composition and metabolism of animals and microorganisms in the sediment of the mangrove forests shall be determined.
Mangroves in Northeastern Brazil
Photo: Ulrich Saint-Paul, Leibniz Centre for Tropical Marine Research
Instead of classifying hundreds of animal species by their appearance, this technique allows conclusions to be drawn about the biodiversity of the region using DNA traces.
The researchers will also focus on the microorganisms – the bacteria, fungi and algae – which live in the muddy sediment of the mangroves. Metagenomic methods can also identify species that cannot be kept in culture.
The fallen leaves of the mangrove trees – they cast off up to three kilograms of leaves per square meter annually – supply nutrients to these microbes, which in turn drive complex ecosystem processes. Ultimately, numerous local and global ecosystem services of the mangroves depend on these processes in the sediment.
The project spans the entire globe and covers a wide variety of vegetation types of mangrove forests. Colombia, Brazil, South Africa, Oman, Singapore and Australia are just some of the stations that the researchers will be heading to.
"Perhaps the most challenging task will be to take sterile sediment samples in the mud of the mangroves in sultry heat or streaming monsoon rain, which are not microbially contaminated and produce adulterated results," said Martin Zimmer, professor of Mangrove Ecology at the ZMT and director of the joint project.
The research bundles the expertise of four institutions of the Leibniz Association. In addition to the ZMT, the Leibniz Institute of Ecological Urban and Regional Development (IOER) in Dresden, the Leibniz Institute of Plant Biochemistry (IPB) in Halle, and the Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures in Braunschweig are involved.
“We also plan to incorporate socio-economic studies on the human use of mangroves. The scope of the research project spans the spectrum from microbial processes in the sediment to sustainable use by humans,” said Martin Zimmer. “Ultimately, our findings shall contribute to the worldwide protection of this valuable ecosystem.”
Along with coral reefs and tropical rainforests, mangroves are among the most productive ecosystems on earth. In the general perception they are still quite underestimated, although they fulfil immensely important tasks. Mangrove forests store enormous amounts of carbon and nitrogen in their sediments, thus contributing significantly to climate protection. They protect coasts from storm surges and erosion and with their food resources protect the coastal population from having to migrate. However, up to eight percent of the mangrove area worldwide is lost each year through clearing and deforestation.
Prof. Dr. Martin Zimmer | Leader WG Mangrove Ecology
Leibniz Centre for Tropical Marine Research (ZMT)
Mail: email@example.com | Tel: 0421 - 238 00-161
Dr. Susanne Eickhoff | Public Relations
Leibniz Centre for Tropical Marine Research (ZMT)
Mail: firstname.lastname@example.org | Tel: 0421 - 238 00-37
About the Leibniz Centre for Tropical Marine Research
In research and education the Leibniz Centre for Tropical Marine Research (ZMT) in Bremen is dedicated to the better understanding of tropical coastal ecosystems. As an interdisciplinary Leibniz institute the ZMT conducts research on the structure and functioning of tropical coastal ecosystems and their reaction to natural changes and human interactions. It aims to provide a scientific basis for the protection and sustainable use of these ecosystems. The ZMT works in close cooperation with partners in the tropics, where it supports capacity building and the development of infrastructures in the area of sustainable coastal zone management. The ZMT is a member of the Leibniz Association.
Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Life Sciences
16.07.2018 | Earth Sciences | <urn:uuid:1aa7611d-498c-4d76-a20a-2980702dba29> | 3.25 | 1,624 | Content Listing | Science & Tech. | 33.985987 | 95,636,303 |
A new method provides a three-dimensional identikit of chromosomes
Genome sequencing is a milestone in modern biology as it allows access to the entire "list of instructions" (the chemical sequence of genetic makeup) for the development and function of organisms. Sequencing the genome is a bit like writing down the exact order of the colour of beads in a necklace: knowing how they are arranged along the thread gives us no indication as to the shape of the necklace.
The shape of the DNA strand can be highly complex, given that the chromosomes are loosely arranged in an apparently chaotic tangle in the cell nucleus. Since the shape of chromosomes may have a decisive effect on their function, it is important that it should be characterised, in part because scientists think the DNA tangle in the nucleus is only apparently chaotic and that it has instead a specific "geography" for each tissue and stage of cell life.
"Arriving at a precise description of the shape of the DNA tangle is unfortunately incredibly complicated", explains Cristian Micheletti, SISSA professor and coordinator of the new study. "In our case, we used experimental data on 'proximity pairs'".
"Imagine having to create a map of a city", he explains, "based only on information like 'the post office is opposite the station', 'the chemist is close to the gym', 'the fruit and vegetable market is near the football field' and so on. If you have only a small number of such statements to go by, your map will be approximate and in some cases indeterminate. But if you have hundreds, thousands or even more, then your map will become increasingly precise and accurate. This is the logic we followed".
"Proximity pairs" therefore refers to information on the closeness of two points on the map. In the case of nuclear DNA, this information was provided by a technique (which Micheletti defines as "brilliant") known as Hi-C, developed by North American research groups in 2010. In this chemical-physical technique, bits of genome located close to each another in the nucleus are tied together and then identified by their sequence.
By collecting large numbers of these proximity pairs scientists discovered which points of the chromosomes lie close to each other in the nucleus. While this is today the most powerful technique for investigating DNA organisation in the nucleus, it is still inadequate for inferring its overall shape. "For this reason, we thought we would try to go 'further'", comments Micheletti.
Federica Sgorbissa | EurekAlert!
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Materials Sciences
18.07.2018 | Life Sciences
18.07.2018 | Health and Medicine | <urn:uuid:0d2a55cb-ba30-44a8-b4c2-aca71dd35c29> | 3.59375 | 1,156 | Content Listing | Science & Tech. | 38.956127 | 95,636,304 |
Carbon-14 datin of ancient objects requires that material to be organic in order to assay its age. You hear someone sat that a dinosaur bone ws carbon dated to be 75 million yaers old. What are two specific reasons that this claim is incorrect?© BrainMass Inc. brainmass.com July 20, 2018, 9:52 pm ad1c9bdddf
As soon as a living organism dies, it stops taking in new carbon. The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced. The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample. By looking at the ratio of carbon-12 to ...
The solution explains the concept of using radioactive element carbon-14 to track the age of a piece of dinosaur bone. | <urn:uuid:a8c73ab5-9996-49c4-a5a3-804650f1900b> | 3.359375 | 195 | Truncated | Science & Tech. | 76.540175 | 95,636,325 |
John C. Davis, Geoffrey C. Bohling, 2001. "The Search for Patterns in Ice-Core Temperature Curves", Geological Perspectives of Global Climate Change, Lee C. Gerhard, William E. Harrison, Bernold M. Hanson
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Predictions of global climate change are based on large computer-simulation models that are “history-matched” to weather records compiled from the early nineteenth century onward. Climate-change model forecasts would be more convincing if they were based on the natural records of the Holocene (≈10,000 years) and were capable of simulating climate characteristics of this epoch. Temperature records estimated from δ18O measurements on ice cores from the Greenland ice cap and the Antarctic could be used to develop models based on geochronological data rather than historically brief weather records.
The 20-year average record of δ18O values from the Greenland Ice Sheet Project 2 (GISP2) ice core exhibits a long-term trend of declining temperatures over most of the Holocene, except during the last 100 years, when temperatures have increased—a change widely blamed on carbon-dioxide (CO2) emissions from fossil fuels. However, the range in temperatures since the start of the industrial age is typical for the Holocene, and the current rate of increase in temperatures is unusual but not unprecedented. Past periods of consistently increasing (or decreasing) temperatures have not persisted much longer than the current interval, so temperature trends may well reverse in the near future. There are distinct cyclic patterns in temperatures recorded in the GISP2 ice core, including a pronounced sawtoothed 560-year sequence of relatively abrupt change followed by a gradual reversal. The present trend may be the initial phase of such a pattern. In summary, the present climate does not appear significantly different from the past climate at times prior to industrialization. | <urn:uuid:75ca3b4e-ad49-4666-bc27-7c45b4634d8a> | 3.265625 | 385 | Academic Writing | Science & Tech. | 25.129605 | 95,636,327 |
Ozone pollution across the continental United States will become far more difficult to keep in check as temperatures rise, according to new research. The detailed study shows that Americans face the risk of a 70 percent increase in unhealthy summertime ozone levels by 2050.
This is because warmer temperatures and other changes in the atmosphere related to a changing climate, including higher atmospheric levels of methane, spur chemical reactions that lead to ozone.
Visible pollutants can react with sunlight to create invisible ozone pollution, which frequently reaches unhealthy levels in major cities like Los Angeles. New research indicates that the pollution may worsen in coming decades due to chemical reactions in the air associated with climate change.
credit: Thomas/Wikimedia Commons
Unless emissions of specific pollutants that are associated with the formation of ozone are sharply cut, almost all of the continental United States will experience at least a few days with unhealthy air during the summers, the research shows. Heavily polluted locations in parts of the East, Midwest, and West Coast in which ozone already frequently exceeds recommended levels could face unhealthy air during most of the summer.
“It doesn’t matter where you are in the United States—climate change has the potential to make your air worse,” said scientist Gabriele Pfister of the National Center for Atmospheric Research (NCAR) in Boulder, Colo., who is lead author of the new study. “A warming planet doesn’t just mean rising temperatures, it also means risking more summertime pollution and the health impacts that come with it.”
However, the research also showed that a sharp reduction in the emissions of certain pollutants would lead to dramatically decreased levels of ozone even as temperatures warm.
The detailed research is one of the first of its type to be conducted with new, highly advanced geoscience supercomputing capabilities. It will be published online this week in the Journal of Geophysical Research-Atmospheres, a journal of the American Geophysical Union.
Ozone and heat
Ozone pollution is not emitted directly, but instead forms as a result of chemical reactions that take place between nitrogen oxides and volatile organic compounds in the presence of sunlight. These gases come from human activities such as combustion of coal and oil as well as natural sources such as emissions from plants.
Unlike ozone in the stratosphere, which benefits life on Earth by blocking ultraviolet radiation from the Sun, ground-level ozone can trigger a number of health problems. These range from coughing and throat irritation to more serious problems, including aggravation of asthma, bronchitis, and emphysema. Even short periods of unhealthy ozone levels can cause local death rates to rise. Ozone pollution also damages crops and other plants.
To examine the impacts of climate change on ozone pollution, Pfister and her colleagues looked at two scenarios. In one, emissions of nitrogen oxides and volatile organic compounds from human activities would continue at current levels through 2050. In the other, emissions would be cut by 60-70 percent. Both scenarios assumed continued greenhouse gas emissions with significant warming.
The researchers found that, if emissions continue at present-day rates, the number of eight-hour periods in which ozone would exceed 75 parts per billion (ppb) would jump by 70 percent on average across the United States by 2050. The 75 ppb level over eight hours is the threshold that is considered unhealthy by the Environmental Protection Agency. (The agency is considering tightening the standard to a value between 65 and 70 ppb over eight hours.)
Overall, the study found that, 90 percent of the time, ozone levels would range from 30 to 87 parts per billion (ppb) in 2050 compared with an estimated 31 to 79 ppb in the present. Although the range itself shifts only slightly, the result is a much larger number of days above the threshold now considered unhealthy.
There are three primary reasons for the increase in ozone with climate change:
In the second scenario, Pfister and her colleagues found that sharp reductions in nitrogen oxides and volatile organic compounds could reduce ozone pollution even as the climate warms. In fact, 90 percent of the time, ozone levels would range from 27 to 55 ppb. The number of instances when ozone pollution would exceed the 75 ppb level dropped to less than 1 percent of current cases.
“Our work confirms that reducing emissions of ozone precursors would have an enormous effect on the air we all breathe,” Pfister said.
Pfister and a nationwide scientific team expect to learn more about the sources, chemistry and movement of air pollutants this summer when they launch a major field experiment Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) along Colorado’s Front Range.
The role of supercomputing
The new study was among the first conducted on a new supercomputer at NCAR known as Yellowstone, which is capable of very high performance, that has been measured at 1.5 petaflops (1.5 thousand trillion floating point operations per second). The IBM system, supported by funding from the NSF and the University of Wyoming, is one of the world’s most powerful computers specifically dedicated to research in the atmospheric and related sciences.
Scientists used it to simulate pollution levels hour by hour for 39 hypothetical summers. This allowed the team to account for year-to-year variations in meteorological conditions, such as hot and dry vs. cool and wet, thereby getting a more detailed and statistically significant picture of future pollution levels.
To simulate the interplay of global climate with regional pollution conditions, the scientists turned to two of the world’s leading atmospheric models, both based at NCAR and developed through broad collaborations with the atmospheric science community. They used the Community Earth System Model, funded primarily by the Department of Energy and NSF, to simulate global climate as well as atmospheric chemistry conditions. They also used an air chemistry version of the multiagency Weather Research and Forecasting model to obtain a more detailed picture of regional ozone levels.
Even with Yellowstone’s advanced computing speed, it took months to complete the complex simulations.
“This research would not have been possible even just a couple of years ago,” said Pfister. “Without the new computing power made possible by Yellowstone, you cannot depict the necessary detail of future changes in air chemistry over small areas, including the urban centers where most Americans live.”
The work was funded by the National Science Foundation (NSF), which is NCAR’s sponsor, and the U.S. Department of Energy. In addition to NCAR, the study co-authors are from the Pacific Northwest National Laboratory; University of Colorado, Boulder; and North-West University in South Africa.
The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 62,000 members in 144 countries. Join our conversation on Facebook, Twitter, YouTube, and other social media channels.
The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. For news release, images and more: www.ucar.edu/atmosnews. For more information on the Yellowstone supercomputer: http://www2.ucar.edu/atmosnews/big-data/10-ways-yellowstone-will-make-difference. For more information on the FRAPPE field experiment: http://www2.acd.ucar.edu/frappe.
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Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this accepted article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2013JD020932/abstract
Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at email@example.com. Please provide your name, the name of your publication, and your phone number.
Neither the paper nor this press release is under embargo.
“Projections of Future Summertime Ozone over the U.S.”
G. G. Pfister, S. Walters and J.-F. Lamarque: Atmospheric Chemistry Division, NCAR, Boulder, CO, USA;
J. Fast: Pacific Northwest National Laboratory, Richland, WA, USA;
M. C. Barth: Atmospheric Chemistry Division, NCAR, Boulder, CO, USA, and Mesoscale and Microscale Meteorology, NCAR, Boulder, CO, USA;
J. Wong: Atmospheric Chemistry Division, NCAR, Boulder, CO, USA, and University of Colorado, Boulder, CO, USA;
J. Done and G. Holland: Mesoscale and Microscale Meteorology, NCAR, Boulder, CO, USA;
C. L. Bruyère: Mesoscale and Microscale Meteorology, NCAR, Boulder, CO, USA, and Environmental Sciences and Management, North-West University, South Africa.
Contact information for the authors:
Gabriele Pfister: +1 (303) 497-2915, firstname.lastname@example.org
+1 (202) 777-7524
David Hosansky, NCAR/UCAR Media Relations
+1 (303) 497-8611
Zhenya Gallon, NCAR/UCAR Media Relations
+1 (303) 497-8607
+1 (703) 292-7734
Nanci Bompey | American Geophysical Union
Scientists discover Earth's youngest banded iron formation in western China
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
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Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
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13.07.2018 | Life Sciences | <urn:uuid:f0fa816e-b888-4d77-a1a9-31aaea9fd089> | 3.65625 | 2,653 | Knowledge Article | Science & Tech. | 38.704529 | 95,636,361 |
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By: National Research Council
188 pages, colour illustrations, maps
The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long-term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society.
This volume reviews the current state of knowledge, explores gaps in our understanding, and identifies several key findings.
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Java Applets: Interactive Programming
- The purpose of this assignment is
We're going to create a slideshow of images, with a previous and next button so
the user can walk through the slideshow via buttons.
- You're going to need some images, so copy some from another project or
import some in to your working project.
- Create a new class named SlideshowUsingButtons
- Add an instance variable for an Image named photo.
- Add an array of ImageIcon objects named icons, which will keep track of
all the images in the Slideshow.
- Add a JLabel instance variable named imgLabel which is the label displaying
the current image in the slideshow.
- Create the init method, and set the layout to FlowLayout.
- Inside the init method, instantiate the array icons to the size of 4.
- Inside the init method, grab one of the images and store in photo.
Then create an ImageIcon object on photo and save it in the first spot in
the array icons.
- Repeat the above step for the other 3 images, storing in to subsequent spots in the array.
- Inside the init method, instantiate the JLabel variable imgLabel with the
first ImageIcon in your array icons.
- Inside the init method, add the imgLabel to the applet.
- Test the applet so far by running it, making sure the first image appears.
Make sure you have images available to display!
Now let's add the buttons to walk through the list of images.
- At the top of your program, add JButton instance variables: one for prev, one for next. When the user clicks on each button, it will scroll one way or another through the list of images.
- Inside the init method, instantiate the two buttons you created.
- Inside the init method, add the two buttons, on either side of the JLabel being displayed.
- Test the program to ensure the buttons appear correctly.
Now let's add events to the buttons to walk through the list of images.
- To add events, add the import statement, implements listener, and
add listeners to both buttons and set up the actionPerformed method.
- To keep track of the current image being displayed, add an instance variable
named currentIndex and initialize it to zero. This will be the index in to our
array of ImageIcons.
- Inside the actionPerformed method, check to see if the source of the event was
the next button. If it was, then call the method setupIcon with the value of
the currentIndex plus one - stating that we want to display the next image.
If the source of the event was the previous button, then call the method setupIcon
with the value of the currentIndex minus one - display the previous image.
- Now we have to write the setupIcon method. Set up the method
to return nothing and takes the new index as a parameter.
The purpose of the method is to set the currentIndex to the new index, then
enable/disable the prev/next buttons based on where we are with the index.
If we're at the beginning of the list, we need to disable the previous button.
If we're at the end of the list, we need to disable the next button.
- First set the currentIndex to the new index passed in to the method.
- Now set the icon on the label imgLabel with the icon based on the
new index value.
- Now set both the previous and next buttons to enabled.
- Now we'll decide which of the buttons, if any, need to be disabled.
Check to see if the new index is zero. If it is, disable the previous button.
Check to see if the new index is the last one in the array. If it is, disable the next button.
- Try running your program now. Doesn't quite work right? What didn't work?
- At the end of the actionPerformed method, we need to add the call to repaint( )
to force the applet to redraw the screen.
We can also arrange the images such that they're all centered:
- To center all of the images, go back to the init method and call the method
setHorizontalAlignment on the JLabel imgLabel and send it the parameter
Copyright © 2006-2007: E.S.Boese All rights reserved. | <urn:uuid:9ee7c5a2-c163-4c90-85c0-b2900a505da0> | 3.4375 | 932 | Tutorial | Software Dev. | 59.895203 | 95,636,393 |
Observations of a freshwater pulse induced by Typhoon Morakot off the northern coast of Taiwan in August 2009
In this paper we describe large-scale impacts from a typhoon on the circulation over the continental shelf and slope north of Taiwan. Typhoon Morakot was a category 2 tropical storm that landed in central Taiwan, but caused destruction primarily in southern Taiwan from Aug. 8–10, 2009. The typhoon brought record-breaking rainfall; approximately 3 m accumulated over four days in southern Taiwan. River discharge on the west coast of Taiwan increased rapidly from Aug. 6–7 and peaked on Aug. 8, yielding a total volume 27.2 km3 of freshwater discharged off the west coast of Taiwan over five days (Aug. 6–10). The freshwater mixed with ambient seawater, and was carried primarily by the northeastward-flowing Taiwan Strait current to the sea off the northern coast of Taiwan. Two joint surveys each measured the hydrography and current velocity in the Taiwan Strait and off the northeastern coast of Taiwan roughly one week and two and a half weeks after Morakot. The first survey observed an Ω-shaped freshwater pulse off the northern tip of Taiwan, in which the salinity was ∼1 lower than the climatological mean salinity. The freshwater pulse met the Kuroshio and formed a density front off the northeastern coast of Taiwan. The hydrographic data obtained in the second survey suggested that the major freshwater pulse left the sea off the northern and northeastern coasts of Taiwan, which may have been carried by the Kuroshio to the northeast. Biogeochemical sampling conducted after Morakot suggested that the concentrations of nutrients in the upper ocean off the northern coast of Taiwan increased remarkably compared with their normal values. A typhoon-induced biological bloom is attributed to the inputs both from the nutrient-rich river runoff and upwelling of the subsurface Kuroshio water.
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Document Type: Research Article
Publication date: 01 January 2013
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Diel oxygen dynamics and anoxic events in an eutrophic estuary of Waquoit Bay, Massachusetts
- Charlene D’Avanzo, James N. Kremer
- Estuaries SCOPUS
- Coastal and Estuarine Research Federation in 1994
- Cited Count
- Springer JSTOR
As a result of nutrient loading from septic systems, a thick canopy of macroalgae covers the bottom of Waquoit Bay, an embayment on Cape Cod, Massachusetts. Using automated conductivity-temperature-oxygen recorders and manual profiles, we measured diel water column O2 changes during summer in the Childs River, the estuary of the bay with the highest housing density. At dawn in midsummer, bottom waters in the Childs River are chronically hypoxic due to high rates of benthic respiration. On sunny days benthic photosynthesis drives bottom water O2 to 10–15 mg l−1 by afternoon. The extent of the daily O2 excursion is directly proportional to daily irradiance. Large diel O2 excursions in bottom water are due to limited mixing of surface and bottom water. Density stratification exceeded two sigma-t units 85% of the time during midsummer in the Childs River. Because of stratification, hypoxia and even anoxia occur in this estuary. The first of several anoxic events was observed in Waquoit Bay in 1988, and we have attempted to evaluate factors that trigger anoxia. High rates of benthic respiration result in anoxia when replenishment of O2 during the day is limited by insufficient light. Our analysis of meteorological records during two recent anoxic events shows that anoxia develops overnight in midsummer during periods of peak summertime temperatures after several days of cloudy, moderately calm weather. Similarly critical conditions existed most summers since 1975, yet anoxic events in the bay have not been reported historically. If climatic warming occurs, anoxic events in the bay may occur more frequently even if algal stocks remain unchanged. Eutrophication of Waquoit Bay is similar to many other embayments in populated coastal areas, and anoxic events may indicate a chronic growing problem in these important ecosystems. However, in shallow, stratified embayments, anoxia may be transient and easily missed without frequent monitoring.
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Georgius Agricola, born in 1494, mineralogist, he was a physician who worked at a mining town. He took the knowledge of the miners and wrote a book. Because of this he became known as the father of mineralogy. He died in 1555 at age 61.
Joseph Liouville, born in 1809, mathematician, he discovered transcendental numbers which are numbers that are not solutions to a polynomial. Such as e and e squared (about 2,7). He died in 1882 at age 73.
Josef Stefan, born in 1835, physicist, he was interested in the rate of cooling of hot bodies and said the total radiation of a hot body was proportional to the fourth power of the absolute temperature. Thus if temp is doubled the radiation increased 16 fold. This is called Stefan’s fourth power law. It became known as the Stefan-Boltzman Law. He died in 1893 at age 58.
Peter DeBye, born in 1884, chemist, he worked under Sommerfield. Worked on dipole moments. Debye Huckle theory, He extended Arrhenius theory of ionization. Debye said that salts are completely dissolved but a dragging effect caused by the ions being surrounded by ions of opposite charge make it seem like they are incompletely dissociated. He died in 1966 at age 82.
Walter Baade, born in 1893, astronomer, Gottingen, discovered the planetoid Hidalgo, and Icarus. He located over 300 cepheids in Andromeda. He said there were two sets of stars, bluish, young population 1 stars in the outer galaxy and reddish older population 2 stars in the inner galaxy. He found that cepheid strss occurred in Population 1 and Population 2 stars. He died in 1960 at age 67.
Adolf Butenandt, chemist, he isolated and identified the sex hormones, estrone in 1929, androsterone in 1931, progesterone in 1934. He was forced by Hitler to refuse the Nobel prize but received it after the war. He died in 1995 at age 91.
Sidney Fox, born in 1912, chemist, he worked on the origin of life. Proteinoids were formed from amino acids on hot rocks. They form sphere that take on some of the characteristics of cells. He died in 1998 at age 86.
John Kendrew, born in 1917, chemist, he worked on the structure of myoglobin using X-ray diffraction, he died in 1997 at age 80. | <urn:uuid:2208a365-a7f2-402f-b0b3-562c61c7c420> | 3.21875 | 525 | Listicle | Science & Tech. | 62.096125 | 95,636,461 |
A natural agent against the higly allergenic common ragweed (Ambrosia artemisiifolia), Acontia candefacta was the first insect species intentionally introduced to Europe for biological control of an invasive weed species. Released in 1969 in the Krasnodar and Stavropol regions of the former USSR, the moth has since migrated and increased its range both in eastward and westward directions.
A recent study by researchers from Serbia investigates the expansion of A. candefacta in southeastern Europe. Since its introduction, it has been recorded in Ukraine, Bulgaria, and Romania, and reported for the first time in Serbia in 2009.
Through a combination of years of intense sampling by light trapping across all of Serbia and modeling of the host species using GBIF-mediated occurrences, the team present results indicating the the moth is likely to spread to all areas where the weed is present.
As the radiation of ragweed is expanding with changing climates, so may the range of A. candefacta. Unfortunately, however, current populations appear uncapable of controlling the spread of the harmful weed. | <urn:uuid:8a017daa-9dae-4397-ace2-c29d719fce44> | 3.328125 | 231 | Knowledge Article | Science & Tech. | 29.550013 | 95,636,464 |
The oryx, along with eight others from American and European zoos, was sent to Tunisia in December 2007 for an eventual reintroduction into the wild, where they have been extinct since the late 1970s. Oryx are a type of desert antelope that are mostly white with reddish-brown necks and marks on the face and a long, dark, tufted tail. They stand up to 4 feet and 6 inches tall at the shoulder, and both male and female oryx have curved horns that grow to be several feet long.
Although the animals have been returned to Tunisia, scientists cannot just simply release them into the wild. For now, the oryx are being kept in a 20,000-acre fenced area in the Dghoumes National Park. Within this protected zone, the five males and four females will reproduce and become acclimated to their arid surroundings. Once a sustainable population has been established, possibly a decade or so from now, the fences will come down.
Oryx were once common in the wild. As recently as 1900, there were as many as 1 million of them in North Africa. But their numbers began to dwindle as they were hunted, both for sport and food. To ensure that the same problems do not plague the oryx that are being reintroduced into the wild, the Tunisian government is planning conservation programs to educate local people about the importance of protecting the animals.
The plan to send oryx to Tunisia came about after that country approached the Association of Zoos and Aquariums, the European Association of Zoos and Aquariums, and the Secretariat for the Convention on Migratory Species for help. Population managers for oryx decided which of the animals were the most genetically valuable to send to Tunisia.
Oryx from the National Zoo’s Conservation and Research Center, the Kansas City Zoo, the Fossil Rim Wildlife Center in Texas, The Wilds in Ohio and Texas’ Bamberger Ranch joined oryx from Fota Wildlife Park in Ireland and France’s Le Pal Parc Animalier et D’Attractions in Tunisia in December 2007. The National Zoo’s oryx will provide a significant infusion of valuable genes into the reintroduced population.
Scientists at the National Zoo’s Conservation and Research Center also are continuing important research to help find ways to better manage scimitar-horned oryx, both in the wild and in zoos. National Zoo scientists pioneered artificial insemination techniques for oryx in order to ensure that genetically valuable but behaviorally incompatible pairs could reproduce.
Two oryx are on exhibit at the National Zoo, and several more oryx remain at the Conservation and Research Center.
Sarah Taylor | EurekAlert!
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
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A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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udp - User Datagram Protocol for IPv4
udp_socket = socket(AF_INET, SOCK_DGRAM, 0);
This is an implementation of the User Datagram Protocol described in
RFC 768. It implements a connectionless, unreliable datagram packet
service. Packets may be reordered or duplicated before they arrive. UDP
generates and checks checksums to catch transmission errors.
When a UDP socket is created, its local and remote addresses are unspecified.
Datagrams can be sent immediately using sendto(2)
with a valid destination address as an argument. When connect(2)
called on the socket, the default destination address is set and datagrams can
now be sent using send(2)
without specifying a
destination address. It is still possible to send to other destinations by
passing an address to sendto(2)
. In order to
receive packets, the socket can be bound to a local address first by using
. Otherwise, the socket layer will automatically assign a free
local port out of the range defined by
and bind the socket to
All receive operations return only one packet. When the packet is smaller than
the passed buffer, only that much data is returned; when it is bigger, the
packet is truncated and the MSG_TRUNC
flag is set. MSG_WAITALL
is not supported.
IP options may be sent or received using the socket options described in
. They are processed by the kernel only when the appropriate
parameter is enabled (but still passed to the user even when it
is turned off). See ip(7)
When the MSG_DONTROUTE
flag is set on sending, the destination address
must refer to a local interface address and the packet is sent only to that
By default, Linux UDP does path MTU (Maximum Transmission Unit) discovery. This
means the kernel will keep track of the MTU to a specific target IP address
and return EMSGSIZE
when a UDP packet write exceeds it. When this
happens, the application should decrease the packet size. Path MTU discovery
can be also turned off using the IP_MTU_DISCOVER
socket option or the
file; see ip(7)
When turned off, UDP will fragment outgoing UDP packets that exceed the
interface MTU. However, disabling it is not recommended for performance and
UDP uses the IPv4 sockaddr_in
address format described in ip(7)
All fatal errors will be passed to the user as an error return even when the
socket is not connected. This includes asynchronous errors received from the
network. You may get an error for an earlier packet that was sent on the same
socket. This behavior differs from many other BSD socket implementations which
don't pass any errors unless the socket is connected. Linux's behavior is
mandated by RFC 1122
For compatibility with legacy code, in Linux 2.0 and 2.2 it was possible to set
the SO_BSDCOMPAT SOL_SOCKET
option to receive remote errors only
when the socket has been connected (except for EPROTO
). Locally generated errors are always passed. Support for this
socket option was removed in later kernels; see socket(7)
When the IP_RECVERR
option is enabled, all errors are stored in the
socket error queue, and can be received by recvmsg(2)
System-wide UDP parameter settings can be accessed by files in the directory
- udp_mem (since Linux 2.6.25)
- This is a vector of three integers governing the number of
pages allowed for queueing by all UDP sockets.
- Below this number of pages, UDP is not bothered about its
memory appetite. When the amount of memory allocated by UDP exceeds this
number, UDP starts to moderate memory usage.
- This value was introduced to follow the format of
tcp_mem (see tcp(7)).
- Number of pages allowed for queueing by all UDP
- Defaults values for these three items are calculated at
boot time from the amount of available memory.
- udp_rmem_min (integer; default value: PAGE_SIZE;
since Linux 2.6.25)
- Minimal size, in bytes, of receive buffers used by UDP
sockets in moderation. Each UDP socket is able to use the size for
receiving data, even if total pages of UDP sockets exceed udp_mem
- udp_wmem_min (integer; default value: PAGE_SIZE;
since Linux 2.6.25)
- Minimal size, in bytes, of send buffer used by UDP sockets
in moderation. Each UDP socket is able to use the size for sending data,
even if total pages of UDP sockets exceed udp_mem pressure.
To set or get a UDP socket option, call getsockopt(2)
to read or
to write the option with the option level argument set to
. Unless otherwise noted, optval
is a pointer to an
- UDP_CORK (since Linux 2.5.44)
- If this option is enabled, then all data output on this
socket is accumulated into a single datagram that is transmitted when the
option is disabled. This option should not be used in code intended to be
These ioctls can be accessed using ioctl(2)
. The correct syntax is:
error = ioctl(udp_socket, ioctl_type, &value);
- FIONREAD (SIOCINQ)
- Gets a pointer to an integer as argument. Returns the size
of the next pending datagram in the integer in bytes, or 0 when no
datagram is pending. Warning: Using FIONREAD, it is
impossible to distinguish the case where no datagram is pending from the
case where the next pending datagram contains zero bytes of data. It is
safer to use select(2), poll(2), or epoll(7) to
distinguish these cases.
- TIOCOUTQ (SIOCOUTQ)
- Returns the number of data bytes in the local send queue.
Supported only with Linux 2.4 and above.
In addition, all ioctls documented in ip(7)
All errors documented for socket(7)
may be returned by a
send or receive on a UDP socket.
- No receiver was associated with the destination address.
This might be caused by a previous packet sent over the socket.
is a new feature in Linux 2.2.
RFC 768 for the User Datagram Protocol.
RFC 1122 for the host requirements.
RFC 1191 for a description of path MTU discovery.
This page is part of release 4.16 of the Linux man-pages
description of the project, information about reporting bugs, and the latest
version of this page, can be found at | <urn:uuid:00a30b83-e456-4017-946b-7a36b294646b> | 3.296875 | 1,480 | Documentation | Software Dev. | 52.455614 | 95,636,556 |
Authors: O. Katsuda, S. Saito and K. Takahashi
Affilation: Tokyo Institute of Technology, Japan
Pages: 426 - 429
Keywords: micromanipulation, liquid bridge, phase transition, condensation
The size of an object has decreased in the electrical and mechanical engineering field for fabricating highly functional microelectro-mechanical systems and photonic crystals. In micromanipulation, even if we can pickup micro-objects, it is very difficult to detach the micro-objects because adhesional force is dominant. Tanikawa et al. have detached micro-objects by using a micro-drop. This indicates that capillary force is effective in micromanipulation. Obata et al. have shown that capillary force can be controlled by regulation of liquid bridge volume. J. Liu et al., have fabricated a manipulation system named freeze tweezer based on freezing force to manipulate a wide variety of objects. Freeze tweezer has been controlled temperature by means of the Joule-Thompson throttling effect. However, they have not solved the detaching problem of adhesion phenomenon completely. In this study, our group manipulates micro-objects with capillary force by condensing water from the atmosphere. This condensed water forms a water bridge. The water bridge can be controlled by evaporation and condensation. A Peltier device is used for temperature control in order to achieve water phase transition. By using this method, we have achieved repeatable micromanipulation with simple equipments. We insist this wide applicable method can be effective in micromanipulation automation.
Nanotech Conference Proceedings are now published in the TechConnect Briefs | <urn:uuid:02c2789e-7349-45d6-9815-318250b3045d> | 2.578125 | 346 | Academic Writing | Science & Tech. | 15.806584 | 95,636,561 |
The direct influence of black carbon, or soot, on warming the climate could be about twice previous estimates, according to an in-depth study published today in the Journal of Geophysical Research-Atmospheres, a publication of the American Geophysical Union.
Accounting for all of the ways black carbon can affect climate, it is believed to have a warming effect of about 1.1 Watts per square meter (W/m2), approximately two-thirds of the effect of the largest man made contributor to global warming – carbon dioxide.
“This study confirms and goes beyond other research that suggested black carbon has a strong warming effect on climate, just ahead of methane,” said co-lead author David Fahey of the U.S. National Oceanic and Atmospheric Administration (NOAA). The study, a four-year, 232-page effort, led by the International Global Atmospheric Chemistry (IGAC) Project, is likely to guide research efforts, climate modeling, and policy for years to come, the authors and other scientists familiar with the paper said..
The report’s best estimate of direct climate influence by black carbon is about a factor of two higher than most previous work. This includes the estimates in the 2007 Intergovernmental Panel on Climate Change (IPCC) Assessment, which were based on the best available evidence and analysis at that time.
Scientists have spent the years since the last IPCC assessment improving estimates, but the new assessment notes that emissions in some regions are probably higher than estimated. This is consistent with other research that also hinted at significant under-estimates in some regions’ black carbon emissions.The results indicate that there may be a greater potential to curb warming by reducing black carbon emissions than previously thought.
Black carbon is a significant cause of the rapid warming in the Northern Hemisphere at mid to high latitudes, including the northern United States, Canada, northern Europe and northern Asia, according to the report. The particles’ impacts can also be felt farther south, inducing changes in rainfall patterns from the Asian Monsoon. Curbing black carbon emissions could therefore have significant impact on reducing regional climate change while having a positive impact on human health by reducing the amount of damage the particles cause to the respiratory and cardiovascular systems.“Policy makers, like the Climate and Clean Air Coalition, are talking about ways to slow global warming by reducing black carbon emissions,” said co-lead author Tami Bond of the University of Illinois at Urbana-Champaign. “This study shows that this is a viable option for some black carbon sources and since black carbon is short-lived, the impacts would be noticed immediately. Mitigating black carbon is good for curbing short-term climate change, but to really solve the long-term climate problem, carbon dioxide emissions must also be reduced.”
Or, you may order a copy of the final paper by emailing your request to Kate Ramsayer at email@example.com. Please provide your name, the name of your publication, and your phone number.
Neither the paper nor this press release are under embargo.
“Bounding the role of black carbon in the climate system: A scientific assessment”Authors (* indicates co-lead authors):
Contact information for the authors:Tami Bond, Telephone: +1 (217) 244-5277, Email: firstname.lastname@example.org
Kate Ramsayer | American Geophysical Union
Further reports about: > American Geophysical Union > Atmospheric > Climate change > Earth's magnetic field > Geophysical Research > Illinois River Watershed > Telephone support > Urbana-Champaign > atmosphere > black carbon > black populations > carbon dioxide > carbon emission > carbon source > diesel engines > global warming > warming effect
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences | <urn:uuid:a36fc977-60b9-4fe2-8f1a-0a935877b755> | 3.65625 | 1,337 | Content Listing | Science & Tech. | 34.862769 | 95,636,563 |
You may have heard some mixed opinions about the state of coral reefs. Some will argue that coral conditions are in a natural flux, or that reefs will have time to adapt to our changing oceans. Others have found that coral populations have sustained irreparable damage. Now several new studies help show that things are a LOT more complicated than you might imagine.
With proper management of coral reefs that defend Pacific Islands and provide important sea health and climate records, the reefs might be able to continue growing vertically.
Coral-like nanoplates made from aluminum oxide were recently introduced by Chinese researchers. They are powerful removers of mercury from ocean water, so far.
For three years beginning in August, 400 underwater video locations all over the globe will record valuable information on sharks, rays and skates and their relationship to reefs.
Coral that was killed during tectonic-plate movement near the Solomon Islands shows earthquake history and helps with some predictions, say researchers.
Using coral genes from the Great Barrier Reef and another reef 300 miles to the south, researchers say that genes can be adjusted for warming temperatures.
Coral reefs have been the subject of much research given the ongoing threats they are dealing with related to climate change. Ocean acidification, for one, is wreaking havoc on these delicate ecosystems, but a remarkable new study says that coral reefs in Palau may be able to defy the odds.
Coral reefs worldwide are taking a beating from global warming, and while new research shows that a certain species of invasive microbe may protect them, it comes at a cost.
The iconic Great Barrier Reef in Australia avoided being put on the World Heritage Site's "in danger" list, based on a UNESCO draft report, however concerns were still raised about its future in the long term.
Coral reefs are rapidly diminishing, and new research says that climate engineering, or geoengineering, could be the key to saving them from fatal mass bleaching events.
It's no secret that the Great Barrier Reef is in danger as climate change and ocean acidification diminish coral populations, but now new research suggests that an ancient slowdown that occurred after the Ice Age warned this iconic ecosystem of its bleak future.
A wealth of research has warned that corals reefs, true reservoirs of biodiversity, are seriously threatened by human activities and climate change. But now researchers are offering a glimmer of hope, finding that corals may not be doomed to disappear after all.
It is no secret that in the midst of climate change, coral reefs around the world are suffering. However, a warming world is not the only factor putting these reefs in danger - overfishing also plagues these colorful ecosystems. And now new research offers a glimmer of hope, finding that fish are the answer to their problems.
It's no secret that the world's coral reefs are rapidly declining, taking the one-two punch that is warming temperatures and mounting ocean acidification. However, there is hope, and it's coming straight from an unknown member of the natural world. Researchers have just discovered a new species of algae, and it's one that seems to be able to help corals survive otherwise deadly temperatures.
Giant clams have been a hard-to-miss part of coral reef ecosystems for the greater part of the last 38 million years. However, experts will be quick to admit that the part they play in these incredible systems remains rather shrouded in mystery. Now a new study hopes to pull back the veil and further our understanding of these clam colossi. | <urn:uuid:52b383fa-5a6a-4b93-a17d-79a497e0e19a> | 3.59375 | 715 | Content Listing | Science & Tech. | 38.663382 | 95,636,564 |
Species Detail - Red-necked Phalarope (Phalaropus lobatus) - Species information displayed is based on all datasets.
Terrestrial Map - 10kmDistribution of the number of records recorded within each 10km grid square (ITM).
Marine Map - 50kmDistribution of the number of records recorded within each 50km grid square (WGS84).
Protected Species: Wildlife Acts || Protected Species: EU Birds Directive || Protected Species: EU Birds Directive >> Annex I Bird Species || Threatened Species: Birds of Conservation Concern || Threatened Species: Birds of Conservation Concern >> Birds of Conservation Concern - Red List
20 June (recorded in 2014)
19 December (recorded in 1956)
National Biodiversity Data Centre, Ireland, Red-necked Phalarope (Phalaropus lobatus), accessed 16 July 2018, <https://maps.biodiversityireland.ie/Species/10081> | <urn:uuid:e85df495-dab2-4bbb-bf05-d52070c0bc5b> | 2.828125 | 201 | Structured Data | Science & Tech. | 21.199297 | 95,636,577 |
The geographical characteristics of an area dictate which renewable energy sources will work best. Because renewable energy is inherently, though predictably, intermittent, governments will need to build supplementary systems. Basically, no single technology will answer all of the world’s needs. However, a “portfolio” of technologies should do the trick. Businessman and climate change expert Chris Goodall describes 10 technologies in intricate detail, from the well-known to the obscure, and explains clearly which will work where, and why. Each technology has the potential to reduce the world’s annual carbon dioxide output by 10%. Although quite technical, getAbstract recommends this book to businesspeople, plant managers, home owners and others who value social responsibility and sustainability.
In this summary, you will learn
- What the 10 most promising technologies are for mitigating climate change;
- What strengths and drawbacks pertain to each technology; and
- How governments can encourage the use of renewable resources.
About the Author
Chris Goodall is an expert on climate change issues. He edits the Carbon Commentary Web site and wrote How to Live a Low-Carbon Life.
Comment on this summary
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Profile Books, 2011 | <urn:uuid:6cc22eaa-acc6-4980-88d5-03e1ec7f5c4a> | 3.4375 | 273 | Truncated | Science & Tech. | 29.046388 | 95,636,582 |
Java Script Trigonometric Methods
By Stephen Bucaro
The Java Script Math object provides the trigonometric functions cosine, sine,
tangent, along with many others. All the trigonometric functions return an angular value
in radians. Why use radians rather than degrees?
The 360 degree rotation angle of a circle is totally fabricated by man and is cumbersome
to use in mathematical calculations. Radians are in tune with nature as 2 pi radians rotates
an arc in a complete circle. Radians make it possible to use algebra to manipulate geometric
shapes in Cartesian space (named after the French man Rene Descartes who came up with it while
dabbling in, among other things, mathematics). To put it another way, we probably wouldn't
have 3D games or computer generated movies without radians.
If you still need to work with degrees, the functions shown below can be used to convert
radians to degrees and degrees to radians.
degrees = 360 * radians/(2 * Math.PI);
radians = (2 * Math.PI * degrees)/360;
As an example, lets use the Math.tan function to solve a common trigonometry problem.
We want to determine the height of a structure. We setup a surveyors telescope 100 meters from
the base of the structure and rotate the telescope 33.8 degrees to point at the peak of the
structure. We can use the basic trigonometric equation shown below.
tan = opposite/adjacent
For our problem we need to rearrange the equation to that shown below.
height = tan 33.8 degrees * 100;
Shown below is the code required to solve the problem.
var radians = (2 * Math.PI * 33.8)/360;
var tan = Math.tan(radians);
var height = tan * 100;
The first line of code converts degrees to radians for use with the Math.tan function.
The second line returns the tangent of the angle. Since the tangent is the ratio of the height
of the object to the distance between the surveyors telescope and the structure, multiplying this
distance by the tangent of the angle will provide us with the height of the object. The last
line of code displays the height of the structure (66.9 meters).
numbers, convert numbers to strings and strings to numbers, and perform trigonometric functions
More Java Script Code:
• Java Script Number Object
• Find a Character or a Substring Within a String
• Java Script alert Message Box
• The Conditional Operator
• Define Lines in a String
• Java Script Arithmetic Operators
• Cookie Power Made Easy
• Window Object Properties and Methods
• Comparison Operators | <urn:uuid:5a30089f-aa97-49df-82c1-17613acb5c6f> | 4.1875 | 586 | Tutorial | Software Dev. | 52.994644 | 95,636,607 |
Exploring the structure of a number square: how quickly can you put the number tiles in the right place on the grid?
Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?
Design and test a paper helicopter. What is the best design?
Dotty Six game for an adult and child. Will you be the first to have three sixes in a straight line?
Strike it Out game for an adult and child. Can you stop your partner from being able to go?
This article introduces the idea of generic proof for younger children and illustrates how one example can offer a proof of a general result through unpacking its underlying structure.
The Enigma Project's James Grime has created a video code challenge. Watch it here!
Dotty Six is a simple dice game that you can adapt in many ways.
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
Explore Alex's number plumber. What questions would you like to ask? Don't forget to keep visiting NRICH projects site for the latest developments and questions.
Can you visualise whether these nets fold up into 3D shapes? Watch the videos each time to see if you were correct.
A brief video looking at how you can sometimes use symmetry to distinguish knots. Can you use this idea to investigate the differences between the granny knot and the reef knot?
Alf and Tracy explain how the Kingsfield School maths department use common tasks to encourage all students to think mathematically about key areas in the curriculum.
These models have appeared around the Centre for Mathematical Sciences. Perhaps you would like to try to make some similar models of your own.
Watch the video to see how to fold a square of paper to create a flower. What fraction of the piece of paper is the small triangle?
Video showing how to use the Number Plumber
This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask? | <urn:uuid:324332e8-6433-440b-ada8-38d23b13de5d> | 3.375 | 422 | Content Listing | Science & Tech. | 61.227658 | 95,636,634 |
remanence(redirected from Remanent magnetization)
Also found in: Encyclopedia.
The magnetic induction that remains in a material after removal of the magnetizing field.
[From Middle English remanent, remaining, from Latin remanēns, remanent-, present participle of remanēre, to remain; see remain.]
(General Physics) physics the ability of a material to retain magnetization, equal to the magnetic flux density of the material after the removal of the magnetizing field. Also called: retentivity
[C17: from Latin remanēre to stay behind, remain]
rem•a•nence(ˈrɛm ə nəns)
the magnetic flux that remains in a magnetic circuit after an applied magnetomotive force has been removed. | <urn:uuid:8879e3a7-d78d-4026-9430-970c2c4a0d1f> | 3.359375 | 172 | Structured Data | Science & Tech. | 18.807248 | 95,636,638 |
In topology and related areas of mathematics, a metrizable space is a topological space that is homeomorphic to a metric space. That is, a topological space is said to be metrizable if there is a metric
Metrizable spaces inherit all topological properties from metric spaces. For example, they are Hausdorff paracompact spaces (and hence normal and Tychonoff) and first-countable. However, some properties of the metric, such as completeness, cannot be said to be inherited. This is also true of other structures linked to the metric. A metrizable uniform space, for example, may have a different set of contraction maps than a metric space to which it is homeomorphic.
One of the first widely recognized metrization theorems was Urysohn's metrization theorem. This states that every Hausdorff second-countable regular space is metrizable. So, for example, every second-countable manifold is metrizable. (Historical note: The form of the theorem shown here was in fact proved by Tychonoff in 1926. What Urysohn had shown, in a paper published posthumously in 1925, was that every second-countable normal Hausdorff space is metrizable). The converse does not hold: there exist metric spaces that are not second countable, for example, an uncountable set endowed with the discrete metric. The Nagata–Smirnov metrization theorem, described below, provides a more specific theorem where the converse does hold.
Several other metrization theorems follow as simple corollaries to Urysohn's Theorem. For example, a compact Hausdorff space is metrizable if and only if it is second-countable.
Urysohn's Theorem can be restated as: A topological space is separable and metrizable if and only if it is regular, Hausdorff and second-countable. The Nagata–Smirnov metrization theorem extends this to the non-separable case. It states that a topological space is metrizable if and only if it is regular, Hausdorff and has a σ-locally finite base. A σ-locally finite base is a base which is a union of countably many locally finite collections of open sets. For a closely related theorem see the Bing metrization theorem.
Separable metrizable spaces can also be characterized as those spaces which are homeomorphic to a subspace of the Hilbert cube , i.e. the countably infinite product of the unit interval (with its natural subspace topology from the reals) with itself, endowed with the product topology.
A space is said to be locally metrizable if every point has a metrizable neighbourhood. Smirnov proved that a locally metrizable space is metrizable if and only if it is Hausdorff and paracompact. In particular, a manifold is metrizable if and only if it is paracompact.
The group of unitary operators on a separable Hilbert space endowed with the strong operator topology is metrizable (see Proposition II.1 in ).
Examples of non-metrizable spaces
Non-normal spaces cannot be metrizable; important examples include
- the Zariski topology on an algebraic variety or on the spectrum of a ring, used in algebraic geometry,
- the topological vector space of all functions from the real line R to itself, with the topology of pointwise convergence.
The real line with the lower limit topology is not metrizable. The usual distance function is not a metric on this space because the topology it determines is the usual topology, not the lower limit topology. This space is Hausdorff, paracompact and first countable.
The long line is locally metrizable but not metrizable; in a sense it is "too long".
- Uniformizability, the property of a topological space of being homeomorphic to a uniform space, or equivalently the topology being defined by a family of pseudometrics
- Moore space (topology)
- Apollonian metric
- Nagata–Smirnov metrization theorem
- Bing metrization theorem
- Simon, Jonathan. "Metrization Theorems" (PDF). Retrieved 16 June 2016.
- Munkres, James (1999). Topology (second edition). Pearson. p. 119.
- http://www.math.lsa.umich.edu/~mityab/teaching/m395f10/10_counterexamples.pdf[dead link]
- Neeb, Karl-Hermann, On a theorem of S. Banach. J. Lie Theory 7 (1997), no. 2, 293–300. | <urn:uuid:6546bedd-078e-4f17-bdcf-bf8824f0ebd1> | 3.21875 | 1,040 | Knowledge Article | Science & Tech. | 33.871498 | 95,636,649 |
Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands. A new paper gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.
About 30 million people are dependent on the protection by coral reefs as they live on low-lying coral islands and atolls. At present, some of these islands experience flooding due to wave events a few times per decade.
Aerial photograph of Kwajalein Atoll in the Marshall Islands showing its low-lying islands and coral reefs. A new study gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.
Credit: Curt Storlazzi/USGS
Underwater image of a wave breaking over a coral reef on Kwajalein Atoll in the Republic of the Marshall Islands. This image shows how the high hydrodynamic roughness of live, healthy corals causes friction that induces breaking of waves over coral reefs, reducing wave energy at the shoreline that can cause flooding and island overwash.
Credit: Curt Storlazzi/USGS
It is expected that this rate of flooding will increase due to sea level rise and coral reef decay, as the remaining dead corals are generally smoother in structure, and do less to dissipate wave energy. Loss of coral cover not only causes increased shoreline erosion but also affects the sparse drinking water resources on these islands, which may eventually make these islands uninhabitable.
In order to prevent or mitigate these impacts, coastal managers need know to what extent their reef system may lose its protective function so that they can take action. The new study by researchers from the Dutch independent institute for applied research Deltares and the U.S. Geological Survey gives guidance on a local reef’s sensitivity to change. The new research has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
To gain insight into effects of changing conditions on coral reefs, the study authors used Xbeach, an open-source wave model. The computer model was first validated using field measurements obtained on the Kwajalein Atoll in the Marshall Islands in the Pacific Ocean, and was then used to investigate what the effects on water levels, waves, and wave-driven runup would be if certain reef properties change. Reef roughness, steepness, width and the total water level on the reef platform are all important factors for coastal managers to consider when planning mitigating measures, according to the study’s authors.
The results suggest that coasts fronted by relatively narrow reefs with steep faces and deeper, smoother reef flats are expected to experience the highest wave runup and thus the greatest potential for island flooding.
Wave runup increases for higher waves, higher water levels that are expected with sea level rise, and lower bed roughness that occurs as coral degrades and becomes smoother. These are all expected effects of climate change. Rising sea levels and climate change will have a significant negative impact on the ability of coral reefs to mitigate the effects of coastal hazards in the future, according to the new study.
The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.
Deltares is an independent institute for applied research in the field of water and subsurface. Visit http://www.deltares.nl
USGS provides science for a changing world. Visit USGS.gov
Notes for Journalists
A PDF copy of the article is available by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2015GL064861/abstract?campaign=wlytk-41855.5282060185
Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at firstname.lastname@example.org. Please provide your name, the name of your publication, and your phone number.
Neither the papers nor this press release is under embargo.
“The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines”
Ellen Quataert: Department of Applied Morphodynamics, Deltares, Delft, Netherlands; and Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands;
Curt Storlazzi: Pacific Coastal and Marine Science Center, U.S. Geological Survey, Santa Cruz, California, USA;
Arnold van Rooijen: Department of Applied Morphodynamics, Deltares, Delft, Netherlands;
Olivia Cheriton: Pacific Coastal and Marine Science Center, U.S. Geological Survey, Santa Cruz, California, USA;
Ap van Dongeren: Department of Applied Morphodynamics, Deltares, Delft, Netherlands.
Contact Information for the Authors:
Curt Storlazzi: +1 (831) 295-3429, email@example.com
Ap van Dongeren: +31(0)88335 8351, firstname.lastname@example.org
+1 (202) 777-7524
+1 (650) 329-4006
Mariska van Gelderen
+31 (0)6 13 67 13 70
Nanci Bompey | American Geophysical Union
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences | <urn:uuid:d464546d-9fa2-4f05-ba0f-e730756d963b> | 3.78125 | 1,775 | Knowledge Article | Science & Tech. | 38.427572 | 95,636,656 |
X-Ray Phase Contrast Imaging (XPCI) has been the subject of intensive research over the last ~20 years, because of its potential to transform all applications of X-ray imaging. In XPCI, contrast arises from refraction/interference effects instead of absorption, which leads to the visualization of features classically considered “x-ray invisible” and, more generally, to a significantly enhanced visibility of all details in an image. While until recently it was believed that XPCI was restricted to synchrotron environments, the UCL group has developed a method that works with conventional x-ray sources, hence opening the way to its translation into mainstream use, as well as making XPCI available to a potentially much wider user base. More recently, microscopic and CT implementations of the lab-based method were also developed, as well as a “dark-field” phase-based approach which provides additional, complementary information on the sample at lengthscales below the resolution of the imaging system. Moreover, when implemented with synchrotron sources, the UCL methods outperforms others in terms of phase sensitivity, a feature which is currently being investigated in more detail as it can potentially enable scientific applications previously considered inaccessible. | <urn:uuid:32f69de2-c075-4d81-b465-a6e314cca313> | 2.640625 | 253 | Truncated | Science & Tech. | 1.524394 | 95,636,676 |
NASA's Terra satellite provided an outside look at Tropical Cyclone Pam while the RapidScat instrument that flies aboard the International Space Station provided an inside look at the surface winds generated by the storm. The GPM core satellite provided another inside look at Pam and provided data on where the heavy rainfall was occurring within the storm.
On March 9 and 10, Tropical Cyclone Pam strengthened to hurricane-force as it neared Vanuatu in the Southern Pacific Ocean.
On March 10 (11 p.m. local time), the Vanuatu Meteorology and Geo-Hazards Department (VMGD) issued a Severe Weather Warning Bulletin for the Northern Islands of Vanuatu. The warning noted that Tropical Cyclone Pam was located northeast of the Torba province, and was slowly moving in a south southeasterly direction.
The VMGD forecast noted: Heavy rainfall expected to affect Torba, Sanma and Penama. Flash floods and expansion of river banks possible. People in these affected areas are advised to take extra precautions, especially those areas close to river banks and in low lying areas. For updated warnings, visit: http://www.
The MODIS or Moderate Resolution Imaging Spectroradiometer instrument aboard NASA's Terra satellite captured a visible image of Tropical Cyclone Pam in the South Pacific Ocean on March 9 at 23:00 UTC (7:00 p.m. EDT).
The image showed that Pam's center had consolidated within the previous 24 hours and was represented by a tight band of thunderstorms circling it. A wide band of fragmented thunderstorms in the northern and western quadrants of the storm were wrapping into the center from the north. Another thick, fragmented band of thunderstorms curved from the east to the south and west, where it wrapped into the center of circulation.
The MODIS image showed that the southern band of thunderstorms were over Gaua and Vanua Lava, the largest and second largest of the Banks Islands in Torba Province, Vanuatu.
The GPM or Global Precipitation Mission's Core Observatory flew over Pam on March 9, 2015 at 0501 UTC (1:01 a.m. EDT). Pam formed earlier in the day in the Solomon Islands in the Southern Pacific Ocean. Rainfall from GPM's Microwave Imager (GMI) showed that Pam was dropping rain at a rate of 133.5 mm (5.26 inches) per hour.
A 3-D image of the thunderstorms that make up Pam was created at NASA's Goddard Space Flight Center in Greenbelt, Maryland. In the 3-D image, very powerful thunderstorms measured by GPM's Radar (Ku Band) reached heights of over 16.6 km (10.3 miles).
The precipitation within these tall storms are providing energy called latent heat that drives the circulation of the storm. Usually, the more heat that is being released, the more intense the storm will become. This heating works best when it occurs near the center of the storm.
The International Space Station's RapidScat instrument captured a look at Tropical Cyclone Pam's surface winds. RapidScat measured the winds from March 9 at 3:46 to 5:19 UTC. Measurements revealed that sustained winds at the surface were as high as 56 mph/90 kph/25 meters per second, near the center and northern quadrant of the storm.
On March 10 at 1500 UTC (11 a.m. EDT), Pam's maximum sustained winds had increased to 80 knots (92 mph/148.2 kph). Pam was centered near 10.8 south latitude and 170.2 east longitude, about 651 nautical miles (749.7 miles/ 1,206 km) northwest of Suva, Fiji. Pam has tracked south-southwestward at 4 knots (4.6 mph/7.4 kph).
The Joint Typhoon Warning Center (JTWC) predicts that Pam will be increasingly powerful and become a dangerous category five tropical cyclone on the Saffir-Simpson wind scale. JTWC expects Pam's winds to strengthen to about 140 knots (161.1 mph/259.3 kph) in the next couple of days as it continues in a southerly direction through the Southern Pacific Ocean.
Rob Gutro | EurekAlert!
New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Life Sciences
16.07.2018 | Earth Sciences
16.07.2018 | Physics and Astronomy | <urn:uuid:cde8c2cb-4ab7-4a36-b65f-28bb45b4da9d> | 3.140625 | 1,511 | Content Listing | Science & Tech. | 55.106617 | 95,636,687 |
Variables beginning with a lowercase character are called local variables.
They exist only within a specific part of a program.
They are restricted to a well-defined scope. Here is an example:
localvar = "hello" $globalvar = "goodbye" def amethod # ww w .ja v a 2 s. co m localvar = 10 puts( localvar ) puts( $globalvar ) end def anotherMethod localvar = 500 $globalvar = "bonjour" puts( localvar ) puts( $globalvar ) end
Here, there are two functions, amethod and anotherMethod.
Each of which is declared using the keyword def and contains code up to the keyword end.
There are three local variables called localvar.
One is assigned the value "hello" within the "main scope" of the program.
Two others are assigned integers within the scope of two separate methods.
Since each local variable has a different scope, the assignments have no effect on the other local variables with the same name in different scopes.
A global variable, one that begins with the dollar sign character $, has global scope.
When an assignment is made to a global variable inside a method, that affects the value of that variable else where. | <urn:uuid:8b915dc9-22a2-4696-aad3-48b858cc6db3> | 3.453125 | 266 | Knowledge Article | Software Dev. | 43.877747 | 95,636,695 |
Nanomaterials In Sunscreens And Boats Leave Marine Life Vulnerable
News May 14, 2015
Nanomaterials commonly used in sunscreens and boat-bottom paints are making sea urchin embryos more vulnerable to toxins, according to a study from the University of California, Davis. The authors said this could pose a risk to coastal, marine and freshwater environments.
The study, published in the journal Environmental Science and Technology, is the first to show that the nanomaterials work as chemosensitizers. In cancer treatments, a chemosensitizer makes tumor cells more sensitive to the effects of chemotherapy.
Similarly, nanozinc and nanocopper made developing sea urchin embryos more sensitive to other chemicals, blocking transporters that would otherwise defend them by pumping toxins out of cells.
Stop being defensive: Nanozinc and nanocopper
Nanozinc oxide is used as an additive in cosmetics such as sunscreens, toothpastes and beauty products. Nanocopper oxide is often used for electronics and technology, but also for antifouling paints, which prevent things like barnacles and mussels from attaching to boats.
“At low levels, both of these nanomaterials are nontoxic,” said co-author Gary Cherr, professor and interim director of the UC Davis Bodega Marine Laboratory, and an affiliate of the UC Davis Coastal Marine Sciences Institute. “However, for sea urchins in sensitive life stages, they disrupt the main defense mechanism that would otherwise protect them from environmental toxins.”
Science for safe design
Nanomaterials are tiny chemical substances measured in nanometers, which are about 100,000 times smaller than the diameter of a human hair. Nano-sized particles can enter the body through the skin, ingestion, or inhalation. They are being rapidly introduced across the fields of electronics, medicine and technology, where they are being used to make energy efficient batteries, clean up oil spills, and fight cancer, among many other uses. However, relatively little is known about nanomaterials with respect to the environment and health.
This research is part of the University of California Center for the Environmental Implications of Nanotechnology and supported by the National Science Foundation and the Environmental Protection Agency.
“The hope is the science will try to stay abreast of the use of nanomaterials so there actually can be safe design,” Cherr said. “The nanotechnology industry wants to come up with designs that are practical but still safe for the environment and human health. The UC center is trying to help fine-tune this.”
The study’s other authors include Bing Wu, Cristina Torres-Duarte and Bryan Cole, all from the UC Davis Bodega Marine Laboratory. Wu is also affiliated with Nanjing University in China.
Getting to Know the Microbes that Drive Climate ChangeNews
A new understanding of the microbes and viruses in the thawing permafrost in Sweden may help scientists better predict the pace of climate change.READ MORE
Perinatal Exposure to Phthalates Results in Lower Number of Neurons and Synapses in the Medial Prefrontal CortexNews
Phthalates - chemicals used in plastics belonging to the same class as Bisphenol A (BPA) - can potentially interfere with hormones important for the developing brain.READ MORE | <urn:uuid:784dad70-0854-433d-a4cd-27031663bc53> | 2.9375 | 708 | News Article | Science & Tech. | 18.258918 | 95,636,712 |
Species Detail - Splitpea Shanklet (Collybia cookei) - Species information displayed is based on all datasets.
Terrestrial Map - 10kmDistribution of the number of records recorded within each 10km grid square (ITM).
Marine Map - 50kmDistribution of the number of records recorded within each 50km grid square (WGS84).
Collybia cirrhata sensu Lange (1936), Collybia cirrhata var. cookei, Sclerotium fungorum
(Bres.) J.D. Arnold
15 September (recorded in 1989)
8 October (recorded in 1995)
National Biodiversity Data Centre, Ireland, Splitpea Shanklet (Collybia cookei), accessed 19 July 2018, <https://maps.biodiversityireland.ie/Species/158503> | <urn:uuid:f87efda6-8084-4667-af70-cc70aae30822> | 2.609375 | 184 | Structured Data | Science & Tech. | 43.092374 | 95,636,723 |
August 2, 2017
The Far North Regional Science Hub has been busy this year, and the excitement is only ramping up as National Science Week approaches.
Started in 2016, the Far North Regional Science Hub covers almost 800,000 square km of sparsely populated arid and semi-arid country in northern South Australia. Spruiking science over such a vast area is no small task, yet the Hub has delivered a suite of events across the region.
Since January, 2017, The Hub has hosted botany and weed workshops in Roxby Downs and Andamooka, celebrated Arid Recovery’s 20 year anniversary with desert ecology presentations and made sustainability fun with a screening of Wall-E in the park.
National Science Week promises even more science excitement for the Far North. The Southern Cross Observatory Project is bringing its mobile astronomical observatory to the Australian Arid Lands Botanic Garden. The community will marvel at the night’s sky, viewed up-close and personal like never before.
Roxby’s Mad Scientists return for another year madness, with a free, hands-on event for children and young people. Attendees will experience a mini-science expo, with science experiments galore. And for the photographers, Woomera Area School is hosting a Photography Contest, merging science and art.
Wherever you are, from Port Augusta to Coober Pedy, come along and celebrate science with the Far North Hub! | <urn:uuid:ab930e4e-12b7-4300-85fa-d4d88c5e9f79> | 2.65625 | 299 | News (Org.) | Science & Tech. | 40.148214 | 95,636,760 |
In the journal Angewandte Chemie, Japanese scientists have now introduced a new type of colorfast, environmentally friendly pigment. These consist of submicrometer-sized silicon dioxide particles and carbon black and are simply sprayed on to the desire surface. The resulting color is tough and does not fade.
Organic dyes fade when exposed to UV light. Inorganic pigments do not fade but are often based on toxic heavy metals such as chromium. In contrast, Yukikazu Takeoka, Shinya Yoshioka and their co-workers at the Universities of Nagoya and Osaka have selected silicon dioxide (SiO2), the main component of sand, as the basis for their novel pigments. Submicrometer-sized SiO2 particles look white to the human eye, so where does the color come from?Conventional pigments absorb some portion of visible light; the reflected portions then combine to produce a certain color. A different type of color generation, known as structural color, is broadly found in nature, for example among butterflies: Arrays of very small particles can also appear colored without absorption by causing wavelength-dependent optical interference, refraction, and light scattering. The color depends of the particle size.
The methanol evaporates during the spraying process, so the SiO2 lands on the surface as a dry powder, forming a thin, even membrane of amorphous particles; it is given no chance to crystallize. Furthermore, a polyelectrolyte can be used to stabilize the structure of the colloidal amorphous array. Depending on the particle size, the researchers obtained membranes that ranged in color from whitish blue (230 nm) to whitish pink (360 nm).These amorphous structures only produced very pale colors. However, the team found a solution to this problem: when particles of carbon black were added, the color saturation was significantly increased. The reason for this is that the carbon black particles reduce light scattering over the entire visible spectrum. This new technology thus allows for intensely colored images with many saturated colors as well as Japanese-style paintings in pale colors.
Besides for art objects, the pigments could be used for architectural paints and automotive coatings as well as in cosmetic products.
Author: Yukikazu Takeoka, Nagoya University (Japan), mailto:email@example.com
Title: Production of Colored Pigments with Amorphous Arrays of Black and White Colloidal Particles
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201301321
Yukikazu Takeoka | Angewandte Chemie
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences | <urn:uuid:37be1828-a1fe-4323-b8ad-9a02ea2eb9be> | 3.75 | 1,143 | Content Listing | Science & Tech. | 33.421753 | 95,636,766 |
Enjoy some of the extensive magazine, newspaper and web-based coverage of our work through the years.
Enjoy a sampling of print media featuring Dr. Nichols' efforts collected on ISSU.
By: Emily Laughnan
The moon casts a gauzy, yellow light along the tops of curling waves. It’s after midnight along Florida’s Gulf Coast. Waves knead the shores, repetitive and predictable. Until she arrives.
Like magic, the sea turtle’s shadowy figure remains on shore as the shimmering tide pulls away. Then she hoists her 250-pound body methodically up the white-sand slope; 30 minutes later she reaches an area on the upper banks to lay her eggs.
She tosses sand gently over her offspring and leaves them to incubate. A gathered group murmurs about how heavy and large she appears, how her head is larger than that of any human there. Yet no one can speak about what happens after she vanishes back into the ocean. It’s simply mysterious — that other 99 percent of a female sea turtle’s life.
“The essential question is ‘where are they going?’ ” said Dr. Tony Tucker as he gazed out to sea. Tucker, manager of Mote’s Sea Turtle Conservation and Research Program, is working with scientists around the world to answer this quintessential turtle question by attaching satellite tags to the turtles so resource managers can understand the animals’ life history and better protect their dwindling numbers.
Sea turtle plight
Since the 1950s, scientists have used flipper tags to identify and study individual sea turtles. They’ve learned a lot about turtle nesting areas, diet and body dimensions — ranging from the average size of an 80 pound, 3-foot-long Kemp’s ridley to a 1-ton, 8-foot-long leatherback. The size differences hint at different sea turtle species’ wide range of prey and habitat but that’s all the information really offers — hints. It doesn’t tell researchers much about the places in the sea that are essential to the turtles’ survival. Today five out of the seven sea turtle species are listed as endangered and loggerheads and olive ridleys are listed as threatened.
One of the most striking examples of a declining population is the story of the Kemp’s ridley. The species is known to nest on only one beach in the world, Rancho Nuevo in the Gulf of Mexico. A historical video once captured about 40,000 females nesting at once — all females of this species nest at the same time. The cluster was so massive that a person could have walked across the beach on the turtles’ backs. But by the 1980s, fewer than 300 Kemp’s ridleys were coming ashore to nest at Rancho Nuevo.
Hundreds of books and papers highlight human activities that contribute to the crash of turtle populations: Hunters capture eggs, females and adults for food, art, jewelry and even for aphrodisiacs; nesting beaches erode each year because of coastal development; artificial lights hinder the ability of adult females and hatchlings to find their way back to the sea. Such land-based impacts are now illegal or closely regulated, but resource managers still don’t fully understand the impacts turtles face at sea. With better technology, scientists like Tucker hope that will soon change.
New tools, new insights
For 20 years, scientists have been experimenting with the use of tags that could transmit a turtle’s whereabouts using the satellites that orbit the earth. The early versions lasted a few months. “The first turtle we tracked went from Mexico to Japan,” said Dr. Wallace J. Nichols, co-director of the Blue Ocean Institute and a research associate at the California Academy of Sciences, who was involved in these early studies.
Although these long treks impressed Nichols and others, today science is trying to look at more localized movements to home in on obstacles to the turtles’ coastal migrations. “The more we know about where and what the sea turtles are doing, the more we can keep nets away from them and keep hooks away from them,” he said.
An estimated 55,000 turtles die each year after being drowned in shrimp trawling nets alone, and oil spills are responsible for an estimated 6 percent of the dead turtles that wash up on U.S. shores. If scientists knew more about where turtles were traveling, managers would have more information to help protect them. “Do their inter-nesting areas overlap with harmful algal blooms? Are they swimming into areas that are dredged for beach renourishment projects? Is boat traffic a potential hazard?” Tucker asked.
Logging the lessons
Female loggerheads come each year to sandy beaches near Mote’s Sarasota campus to lay their eggs. At 3 a.m. on a hot July morning, a female crawled ashore on Casey Key. Tucker and a team of volunteers watched as she finished her nest then started her sand-slide return to the sea. The team moved fast, surrounding the turtle with a portable wooden box.
The turtle let out a few snore-like grunts then quieted as a cool, wet towel was draped over her head. The crew measured her — nearly 3 1/2-feet long and 2 1/2-feet wide — then cleaned off clinging barnacles. The volunteers stepped aside as Tucker used a glue gun to carefully squeeze blobs of gray epoxy onto the turtle’s shell. He then placed a tag the size of a Cracker Jack box with a 6-inch antenna on the turtle.
The crew cat-napped for an hour while the first epoxy layer dried, then watched as Tucker dripped more epoxy over the tag, careful to avoid the screw heads on each end. “Saltwater connects the two screws and then the tag shuts off,” Tucker said. When the screws emerge from the water together as the turtle comes up to take a breath the tag turns back on and sends a signal to a satellite. “It’s a saltwater switch. It’s especially for marine animals as they come out of the water.”
Since the first satellite tags were developed, the technology has improved dramatically, Nichols said. They have smaller batteries, are more compact and stick tightly with new adhesives. The quality and data produced from the tags will probably improve even more over the next 10 years.
But the research has a cost — the tags Tucker uses are $3,000 apiece. Scientists like Nichols hope researchers will share data with each other to maximize resources, combine findings and, in the end, learn more about the turtles. “This is expensive stuff, the more people that share data, the better,” he said.
After a second hour to let the epoxy set, the sun rose and the group lifted the wooden box from around the female loggerhead. Complete with a new nickname, “Squirt,” the turtle and her new tag were on their way.
Information from Squirt’s tag is now being picked up by orbiting satellites then relayed to receiving stations. The information is uploaded to the web and the turtle’s location is plotted on a map. Over the next year, researchers will be able to follow the turtle — one of five loggerheads Tony Tucker tagged during the summer of 2005 — on her journeys. Tucker hopes the data will draw international attention to the turtles’ travels and lead to new ways to protect these endangered species. These are the paths of four of the turtles. For updated maps, click here.
How Squirt got her name
In 2004, elementary school science teacher Chris Lener from the New Canaan Country School in Connecticut participated in an Earthwatch expedition focused on Florida’s endangered sea turtles. She worked in Mote’s Sea Turtle Conservation and Research Program capturing, tagging and releasing turtles as part of an ongoing research project.
When it ended, she asked Dr. Tony Tucker how she could stay involved. “I thought it was a great opportunity not just for me, but for our whole school to be involved in,” Lener said. “The project addresses basic marine science as well as environmental and conservation issues that are key to our science curriculum. The project is so exciting and its various components can be used by our science classes across the grade levels.”
Lener applied for a Jeniam Foundation grant to help fund three satellite tags. When she received it, Lener traveled to Sarasota to help with the satellite tagging project, which she will use in lessons for students in grades one through four.
As part of the sponsorship, the students also got to name the three turtles. So now they’re following along as Squirt, Ninja and Yertle travel the oceans. They’ll also be watching two more turtles — sponsored by the Mote Scientific Foundation and a private donor — named Virginia and Casey.
Learn more about: Sea Turtle Conservation and Research
Recent research has confirmed what many boaters already know – you experience emotional, behavioral... continue
TORONTO, July 9, 2018 /CNW/ - According to the National Marine Manufacturers... continue | <urn:uuid:0a935653-ca31-410b-a145-dfe58596fae7> | 3.734375 | 1,916 | Content Listing | Science & Tech. | 55.117959 | 95,636,797 |
Representatives of recreational fisheries interests north and south of the border are concerned that beavers can harm economically important fish stocks due to their dam building activities and potential to block migratory life phases. However, results of a study conducted by scientists at the University of Southampton, funded by Scottish Natural Heritage, indicate that beavers can also have substantial beneficial effects which may outweigh those that are negative.
This is a beaver dam.
Credit: University of Southampton
The study's findings highlight that while the activities of beavers can result in localised and often temporary negative impacts on fish, primarily due to dams impeding their movements and reducing the availability of suitable spawning habitat, these can be at least off-set by the benefits of increased habitat diversity and resulting abundance and productivity of fish, including salmon.
Dr Paul Kemp, a researcher in freshwater fish ecology and fisheries management from the University's International Centre for Ecohydraulics Research, who lesd the study comments that, "the positive findings were more frequently based on quantitative evidence, while discussion of negative impacts was often speculative."
Dr Kemp and his colleagues were surprised that the "weight of evidence" tended to indicate an overall positive effect considering the background of those who participated in the survey. "Most participants were from a fisheries background and whom you might expect would tend to side with the fish, but based on their experience of beaver and fish interactions tended to be positive towards beaver," he says.
Beaver reintroduction has been a contentious issue in Scotland ever since a total of 16 individuals from Norway were released in Argyll in 2009 and 2010 as part of a scientific trial conducted by the Scottish Wildlife Trust, The Royal Zoological Society of Scotland, and the host partners, the Forestry Commission Scotland.
Even more controversy surrounds the establishment of a breeding population of escaped beavers on the River Tay. This has had ramifications south of the border as the Angling Trust has written to Richard Benyon, the UK minister for Fisheries and the Natural Environment, requesting that trapping and destruction of the beavers be urgently undertaken to prevent their spread to England where it is claimed they could damage fisheries.
Researchers carried out a critical view of over 100 sources of peer-reviewed information in which benefits were cited 184 times compared to 119 for the negative effects. Analysis of existing literature indicates that beaver activity can have both positive and negative effects on fish. Negative effects relate to the construction of beaver dams which can temporarily impede the movement of some fish, particularly in narrow rivers and streams, while siltation can cause loss of spawning habitat immediately upstream of dams. But beavers can also have beneficial effects on fish by increasing the variety and area of habitats in streams, and due to the presence of dams and ponds by increasing the abundance of invertebrates, which form the main component of the diet of many stream-dwelling fish, and providing refuge during periods of high or low water flows.
The study, which was published in the leading international fisheries journal Fish and Fisheries, also reports the findings of an expert opinion survey of 49 fisheries managers, scientists, and beaver ecology experts, from Europe and North America, where most of the research has been conducted. More than half (58 per cent) of those who responded believed that the overall impact of beavers on fish populations was positive.
Professor Roger Wheater, the Chair of the Beaver-Salmonid Working Group, says: "I would be very surprised if biodiversity were not increased but our concern continues to be the impact on salmonid spawning areas and the management required to deal with situations where salmonids in any particular system are at risk."
Glenn Harris | EurekAlert!
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Calculate the molarity of PMDA using the results of each standardization titration. Compute the molarity of PMDA from the mass of reagent used to make the PMDA stock solution. Compare these values and determine the percent purity of the solid reagent.
Please provide steps with explanations. Results are in the Excel spreadsheet. Thanks.© BrainMass Inc. brainmass.com July 21, 2018, 1:44 pm ad1c9bdddf
So, you have correctly figured out the molarity of PMDA from the titration data as being 0.1990 M
Now to calculate molarity from mass, ...
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Observational Astronomy: Techniques and Instrumentation (Hardback)Edmund C. Sutton (author)
Hardback 428 Pages / Published: 13/10/2011
- We can order this
Astronomy is fundamentally an observational science and as such it is important for astronomers and astrophysicists to understand how their data are collected and analyzed. This book is a comprehensive review of current observational techniques and instruments. Featuring instruments such as Spitzer, Herschel, Fermi, ALMA, Super-Kamiokande, SNO, IceCube, the Auger Observatory, LIGO and LISA, the book discusses the capabilities and limitations of different types of instruments. It explores the sources and types of noise and provides statistical tools necessary for interpreting observational data. Due to the increasingly important role of statistical analysis, the techniques of Bayesian analysis are discussed, along with sampling techniques and model comparison. With topics ranging from fundamental subjects such as optics, photometry and spectroscopy, to neutrinos, cosmic rays and gravitational waves, this book is essential for graduate students in astronomy and physics. Electronic and colour versions of selected figures are available online at www. cambridge.org/9781107010468.
Publisher: Cambridge University Press
Number of pages: 428
Weight: 980 g
Dimensions: 247 x 174 x 25 mm
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Astronomers Say Planets Hospitable to Life May Be CommonNovember 4, 2013, 1:51 PM HST (Updated November 4, 2013, 5:57 PM)
Astronomers are continuing to collect findings on the possibilities of Earth-like planets from data collected from the now-crippled Kepler Space Telescope.
Scientists gathering for this week’s Kepler Science Conference in California say that a statistical analysis of the first three years of Kepler data suggests that most stars in our Milky Way galaxy have at least one planet.
And the analysis indicates that one in five stars similar to our sun may be home to an Earth-like planet orbiting in a temperate environment.
There are an estimated 100 billion stars in the Milky Way.
This so-called “habitable zone” is the distance from a star in which water can be found in liquid form on a planet’s surface.
That means, statistically speaking, the nearest sun-like star with an Earth-size planet could be only 12 light years away and visible with the naked eye, said University of California Berkeley graduate student Erik Petigura .
Astronomers from UC-Berkely and the University of Hawai`i have been using the Big Island’s Keck Observatory to analyze information from Kepler, which for four years monitored the brightness of more than 150,000 stars, looking for slight changes in their brightness suggesting the presence of orbiting planets.
Although it was announced in August that Kepler had lost a key aiming component, NASA said there is still more than a year’s worth of data remaining to be analyzed.
Its first three years of observing revealed more than 3,500 potential worlds.
UC-Berkeley astronomy professor Geoffrey Marcy cautioned that Earth-size planets in Earth-like orbits are not necessarily conducive to life even if they meet the requirement of not being too hot or too cold.
“Some may have thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive,” Marcy said in a statement from Keck. “Others may have rocky surfaces that could harbor liquid water suitable for living organisms. We don’t know what range of planet types and their environments are suitable for life.”
Even rocky surfaces don’t indicate conditions favorable for life, as the astronomers noted last week in announcing the discovery of the first Earth-sized, rocky planet outside our solar system. They said that planet orbits so close to its star its surface temperature is likely about 2,000 Kelvin.
That’s more than 3,000 degrees Fahrenheit, considerably hotter than magma from Kilauea volcano.
To determine the likelihood of planets that could possibly sustain life as we know it, the Keck astronomers focused on 42,000 stars similar to our sun, and found 603 candidate planets orbiting them. Of those, 10 were Earth-sized and located in the habitable zone.
They then used computer algorithms to measure how many of the latter were missed. Petigura also inputted fake planets into the data to see which ones his program could detect and which it couldn’t.
“What we’re doing is taking a census of extrasolar planets, but we can’t knock on every door,” Petigura said. “Only after injecting these fake planets and measuring how many we actually found, could we really pin down the number of real planets that we missed.”
Accounting for missed planets, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, allowed them to estimate that 22% of all sun-like stars in the galaxy have Earth-size planets in their habitable zones. | <urn:uuid:eba7ea16-21c2-477a-a7b7-28eaf268883b> | 3.375 | 779 | News Article | Science & Tech. | 40.669177 | 95,636,885 |
The effects of roads on carnivores have obviously been underestimated in worldwide species conservation. This is the conclusion of the first comprehensive global study on this topic, which has been published in the scientific journal “Global Ecology and Biogeography” by an international research team from Germany and Portugal. The protection status of several species that are severely affected by roads cut through their habitat should be reconsidered, the researchers say.
The first global overview of the effects of roads on carnivores offers new insights for the protection of well-known species such as the puma (Puma concolor), the American black bear (Ursus americanus) and the brown bear (Ursus arctos). According to the study, they are among the species whose survival in the long term is most seriously threatened by roads, but for which this hazard has not been fully acknowledged so far.
The current protection status of the brown bear (Ursus arctos) should be reconsidered, the study authors say.
photo: bodsa / Pixabay.com / CC0 Public Domain (https://creativecommons.org/publicdomain/zero/1.0/deed.de)
Among the 5% of carnivores (17 species) that are most affected by roads, nine are currently categorised as “least concern” by the International Union for Conservation of Nature (IUCN), which means that they are regarded as not endangered. “Our results show the necessity of updating the protection status of these species, whose threat from roads has previously been underestimated,” insists Prof Henrique Pereira from the German Centre for Integrative Biodiversity Research (iDiv), the Martin Luther University Halle-Wittenberg and the Portugal Infrastructures Biodiversity Chair/Research Center in Biodiversity and Genetic Resources (CIBIO-InBIO).
Particularly under threat is the Iberian lynx (Lynx pardinus), which lives only in Spain and Portugal; according to estimates, only a few hundred animals remain. The projection in the current study suggests that the species will have died out in 114 years. But while the Iberian lynx is IUCN-classified as “endangered”, other species threatened by roads are not. For example, two species in Japan: According to the projection, the Japanese badger (Meles anakuma) and the Japanese marten (Martes melampus) will have died out in nine and 17 years, respectively, because of the threat from roads.
Those 5% of carnivores (17 species) that are influenced most heavily worldwide by roads include the mammal families of cats, bears, martens, dogs and raccoons. Four species of bear are affected – half of all existing bear species. Surprising for the researchers was that also the stone marten (Martes foina) is among the 17 species most exposed to roads. Although the stone marten is widely distributed and not categorised as endangered by the IUCN, it is often killed by cars. Another species in Germany, the wolf (Canis lupus), is among the top 25% of carnivores (55 species) most exposed to roads globally. It belongs to those predator species that for long-term survival require a large area but whose habitat is cut by roads.
For their study, the researchers considered a total of 232 carnivore species around the world (out of a total of ca. 270 existing species) and assessed how severely these are affected by roads cut through their habitat. To do this, they considered for example the natural mortality rate, the number of offspring and the movement behaviour of a species. From these factors, they calculated the maximum density of roads that a species can cope with. Furthermore, they determined the minimum area of unbroken habitat that a species needs to maintain an enduring healthy population. Finally, they compared these numbers with road network data.
“Our results show that North America and Asia are the regions with the highest number of species most negatively influenced by roads, followed by South America and Europe,” explains Ana Ceia Hasse from iDiv, the MLU and Portugal Infrastructures Biodiversity Chair/CIBIO-InBIO. “But while we had already expected that carnivores would suffer particularly in regions with greater road density, we were surprised to find that even in regions with relatively low road density there are species that are threatened by roads.”
In Africa, for example, roads have a significant effect on the habitats of leopards (Panthera pardus). This is because sensitive species that naturally cover greater distances can be restricted by comparatively few roads. “We did not simply lay roads and habitats of species over one another, but also considered the specific characteristics and requirements of the species in our calculations. In this way we could also identify species that react sensitively to even only a few roads,” says Ceia-Hasse. The methods established in the new study can be used in future for applied purposes – for example for local protection measures, for environmental assessments by authorities, or to integrate the long-term effects of road building into scenarios of the World Bank regarding global biodiversity changes. Tilo Arnhold, Tabea Turrini (iDiv)
Link to press release:
Publication (iDiv/MLU scientists in bold):
Ceia-Hasse, A., Borda-de-Água, L., Grilo, C. and Pereira, H. M. (2017), Global exposure of carnivores to roads. Global Ecology and Biogeography. doi:10.1111/geb.12564. Published online 26.01.2017: http://dx.doi.org/10.1111/geb.12564
The study was financially supported by the German Science Foundation (DFG), the European Regional Development Fund (POCI-01-0145-FEDER-006821) as well the Fundação para a Ciência e a Tecnologia (UID/BIA/50027/2013, PTDC/AAC-AMB/117068/2010, SFRH/BPD/64205/2009).
Ana Ceia Hasse (speaks English and Portuguese)
Doctoral Researcher at the Research Group Biodiversity Conservation at the German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv) and the Martin Luther University Halle-Wittenberg and
Portugal Infrastructures Biodiversity Chair
Research Centre in Biodiversity and Genetic Resources (CIBIO/InBIO), University of Porto
Mobile: + 351 965 232 458 (currently in Portugal)
Prof Henrique Miguel Pereira (speaks English and Portuguese)
Head of Research Group Biodiversity Conservation at the German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), Professor at the Martin Luther University Halle-Wittenberg and
Chair of the Portugal Infrastructures Biodiversity Chair
Research Centre in Biodiversity and Genetic Resources (CIBIO/InBIO), University of Porto
Tinker Visiting Professor
Center for Latin-American Studies
Mobile: +1 650 250 9798 (currently in the USA; reachable every day after 5pm CET)
as well as
Tilo Arnhold, Tabea Turrini
iDiv press office
Phone: +49 341 9733 197
Related press releases:
Earth cut into 600,000 pieces (press release of the HNEE)
Damages caused by bears: Humans determine frequency
Major update of IUCN Red List - “necessary, but not sufficient” says Henrique M. Pereira (German only)
Red List Spatial Data: http://www.iucnredlist.org/technical-documents/spatial-data
OpenStreetMap Data Extracts: http://download.geofabrik.de/
iDiv is a central facility of Leipzig University within the meaning of Section 92 (1) of the Act on Academic Freedom in Higher Education in Saxony (Sächsisches Hoch-schulfreiheitsgesetz, SächsHSFG). It is run together with the Martin Luther University Halle-Wittenberg and the Friedrich Schiller University Jena, as well as in cooperation with the Helmholtz Centre for Environmental Research – UFZ.
The following non-university research institutions are involved as cooperation partners: the Helmholtz Centre for Environmental Research – UFZ, the Max Planck Institute for Biogeochemistry (MPI BGC), the Max Planck Institute for Chemical Ecology (MPI CE), the Max Planck Institute for Evolutionary Anthropology (MPI EVA), the Leibniz Institute DSMZ–German Collection of Micro¬organisms and Cell Cultures, the Leibniz Institute of Plant Biochemistry (IPB), the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) and the Leibniz Institute Senckenberg Museum of Natural History Görlitz (SMNG).
Tilo Arnhold | idw - Informationsdienst Wissenschaft
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
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