in the group that help scientists keep an eye on the galaxies around us by regularly posting the photos they take from their telescopes. when members of the group publish a photograph of the nighttime sky an automated computer application scans their photos for recognizable stars, planets, and nebulae and labels them using flickr ’ s notes function. each photographer gains more information about the photograph that he or she took and astrometry. net gets a new image of the nighttime sky to add to its ever - growing database. in an interview on the flickr developer blog, project leader christopher stumm says that astrometry. net is currently “ using images from around the web to calculate the path comet holmes took through the sky. ” chris messina from san francisco brings us another example of cloud intelligence from a recent shopping trip to officemax where he and his girlfriend were hoping to buy some dry erase boards for their home office. the shopping trip wasn ’ t a success. most of the boards were poor quality and when they did eventually find a product that suited their needs, it was damaged. rather than moving on to the next office supply store chris pulled out his iphone and took a picture with the amazon iphone application of the dry erase board they wanted to buy. the picture is then uploaded to one of amazon ’ s massive data centers where it is posted on mechanical turk, a website that lists “ human intelligence tasks ” that pay anywhere from one penny to five dollars. jeff, for example, will pay you one penny for every sermon time you find listed on a church website. amazon is also willing to pay one penny to anyone who will look at the photo chris uploaded from his iphone application and identify that same product on the amazon website. chris will never know who did the work for him, but within minutes he received a message from amazon with a link to the product he was looking for. i would imagine that just about every tourist who has been to london has taken a picture of big ben. it must be the most photographed clock tower in the world. ten years ago we put those photographs in a photo album to share with our family and friends. more recently we ’ ve become accustomed to sharing them on picasa, flickr, or twitter. but now the tourist snapshots we take are helping create a 3d model of the world : if the cloud is the world brain, then the cameras and microphones on our mobile phones and laptops are its eyes and ears. how many times have you been to a cafe or bar and heard a song that you liked but didn ’ t


: if the cloud is the world brain, then the cameras and microphones on our mobile phones and laptops are its eyes and ears. how many times have you been to a cafe or bar and heard a song that you liked but didn ’ t recognize? today if you help the cloud listen, it will provide you with the information. shazam identifies the song you are listening by sharing a small audio sample with your mobile phone. in turn shazam is able to track the most popular songs as they come out. google ’ s crowdsourced traffic application also highlights the symbiotic relationship between human intelligence and cloud intelligence. when you start the application google will show you traffic conditions on many of the streets around you. in turn, you agree to let google track your speed as you travel ; thus updating their maps with more real - time traffic data. just five years ago it would have cost at least hundreds of thousands of dollars to produce a video with actors on location based all around the world. also, until very recently there was only one man in the world who could attract millions of views when dancing the moonwalk. today we all can. all we have to do is upload a video to eternal moonwalk. the cloud is enabling a new possibilities of creative collaboration. what is the future of collective intelligence? all that we can be sure of is that all intelligence is always collective ; whether it is the collective intelligence of the nucleotides that make up our dna or the billions of neurons in our brain as they produce the thoughts in our heads right now. above is a visualization of the internet made by the opte project. it is a map of us – the internet would not exist were it not for us, and we would each be very different without the internet. just as each individual neuron in our brain is unaware that collectively it is part of a larger self, it is too easy for each of us to forget that, as internet users, we too form parts of a collective whole. and that collective whole is much greater – and different – than the sum of its parts. in many ways the cloud is leading to the centralization of power as it lures us into trusting just a few major corporations with our personal information. on the other hand it creates an architecture of participation that is enabling a larger percentage of the world population to become active citizens rather than just passive consumers. this podium i am speaking at right now was once the sole symbol of power in the room. today a cloud of conversation floats all


web ’ or ' w3 ’ – is the virtual world of network - accessible information available to computers. the web consists of a vast number of ' pages ’, and links. web pages can include text, graphics and images, videos and sound. in november 2004 google claimed to cover 8, 058, 044, 651 web pages. ( wikipedia ' size comparisons ’ ) the web uses a special language and set of rules to create ' web pages ’ – primarily hyper text markup language ( html ) and the hyper text transfer protocol ( http ). ' browsers ’ – software for searching and viewing information on the web – interpret and display information coded in html across the vast ' web ’ of different computer networks and systems. this creates an environment that, for users, appears like a seamless global information system, where people may search, browse and interact. the world wide web was ' invented ’ in 1989 by british - born tim berners - lee when he wrote the first ' web browser ’ – software to interpret and display html ( hyper text mark - up language ) – thereby making the coded material on a multitude of different computers and operating systems uniformly readable in plain english. berners - lee was working at cern, the european particle physics laboratory based in switzerland at the time. as the international physics community used a diverse range of information systems and computer networks, berners - lee wanted to create an efficient way for the different networks to interconnect, share information and communicate with each other. two years later, in 1992, cern released the world wide web. - discuss and research the meanings of the following terms : urls, http, xml / rdf, smil, soap, web accessibility and web applications. - explain the difference between hypertext and hyperlinks. - the world wide web consortium ( w3c ) is the international organisation founded by tim berners - lee that works on developing protocols and guidelines that ensure long - term growth for the web. since 1994, w3c has produced more than ninety web standards, called w3c recommendations that contribute to web interoperability. develop a biography about tim berners - lee for a newspaper feature article. - web applications and dynamic web sites were major developments in the types of interactions that can occur on the web. one simple example is the use of ‘ cookies ’ to remember details about users so that on return to a specific site it is tailored to the needs of that user. the ability to search within websites is another example.


| oracle® database concepts 11g release 2 ( 11. 2 ) | pdf · mobi · epub | this chapter contains the following sections : a process is a mechanism in an operating system that can run a series of steps. the mechanism depends on the operating system. for example, on linux an oracle background process is a linux process. on windows, an oracle background process is a thread of execution within a process. code modules are run by processes. all connected oracle database users must run the following modules to access a database instance : application or oracle database utility a database user runs a database application, such as a precompiler program or a database tool such as sql * plus, that issues sql statements to a database. oracle database code each user has oracle database code executing on his or her behalf that interprets and processes the application ' s sql statements. a process normally runs in its own private memory area. most processes can periodically write to an associated trace file ( see " trace files " ). multiple - process oracle ( also called multiuser oracle ) uses several processes to run different parts of the oracle database code and additional processes for the users — either one process for each connected user or one or more processes shared by multiple users. most databases are multiuser because a primary advantages of a database is managing data needed by multiple users simultaneously. each process in a database instance performs a specific job. by dividing the work of the database and applications into several processes, multiple users and applications can connect to an instance simultaneously while the system gives good performance. a database instance contains or interacts with the following types of processes : client processes run the application or oracle tool code. oracle processes run the oracle database code. oracle processes including the following subtypes : background processes start with the database instance and perform maintenance tasks such as performing instance recovery, cleaning up processes, writing redo buffers to disk, and so on. server processes perform work based on a client request. note : server processes, and the process memory allocated in these processes, run in the instance. the instance continues to function when server processes terminate. slave processes perform additional tasks for a background or server process. the process structure varies depending on the operating system and the choice of oracle database options. for example, the code for connected users can be configured for dedicated server or shared server connections. in a shared server architecture, each server process that runs database code can serve multiple client processes. figure 15 - 1 shows a system global area ( sga ) and background processes using dedicated server connections


can be configured for dedicated server or shared server connections. in a shared server architecture, each server process that runs database code can serve multiple client processes. figure 15 - 1 shows a system global area ( sga ) and background processes using dedicated server connections. for each user connection, the application is run by a client process that is different from the dedicated server process that runs the database code. each client process is associated with its own server process, which has its own program global area ( pga ). when a user runs an application such as a pro * c program or sql * plus, the operating system creates a client process ( sometimes called a user process ) to run the user application. the client application has oracle database libraries linked into it that provide the apis required to communicate with the database. client processes differ in important ways from the oracle processes interacting directly with the instance. the oracle processes servicing the client process can read from and write to the sga, whereas the client process cannot. a client process can run on a host other than the database host, whereas oracle processes cannot. for example, assume that a user on a client host starts sql * plus and connects over the network to database sample on a different host ( the database instance is not started ) : sql > connect sys @ inst1 as sysdba enter password : * * * * * * * * * connected to an idle instance. on the client host, a search of the processes for either sample shows only the sqlplus client process : % ps - ef | grep - e sample - e sqlplus | grep - v grep clientuser 29437 29436 0 15 : 40 pts / 1 00 : 00 : 00 sqlplus as sysdba on the database host, a search of the processes for either sample shows a server process with a nonlocal connection, but no client process : % ps - ef | grep - e sample - e sqlplus | grep - v grep serveruser 29441 1 0 15 : 40? 00 : 00 : 00 oraclesample ( local = no ) a connection is a physical communication pathway between a client process and a database instance. a communication pathway is established using available interprocess communication mechanisms or network software. typically, a connection occurs between a client process and a server process or dispatcher, but it can also occur between a client process and oracle connection manager ( cman ). a session is a logical entity in the database instance memory that represents the


. typically, a connection occurs between a client process and a server process or dispatcher, but it can also occur between a client process and oracle connection manager ( cman ). a session is a logical entity in the database instance memory that represents the state of a current user login to a database. for example, when a user is authenticated by the database with a password, a session is established for this user. a session lasts from the time the user is authenticated by the database until the time the user disconnects or exits the database application. a single connection can have 0, 1, or more sessions established on it. the sessions are independent : a commit in one session does not affect transactions in other sessions. note : if oracle net connection pooling is configured, then it is possible for a connection to drop but leave the sessions intact. multiple sessions can exist concurrently for a single database user. as shown in figure 15 - 2, user hr can have multiple connections to a database. in dedicated server connections, the database creates a server process on behalf of each connection. only the client process that causes the dedicated server to be created uses it. in a shared server connection, many client processes access a single shared server process. figure 15 - 3 illustrates a case in which user hr has a single connection to a database, but this connection has two sessions. generating an autotrace report of sql statement execution statistics re - creates the scenario in figure 15 - 3. example 15 - 2 connects sql * plus to the database as user system and enables tracing, thus creating a new session ( sample output included ). sql > select sid, serial #, paddr from v $ session where username = user ; sid serial # paddr - - - - - - - - - - - - - - - - - - 90 91 3be2e41c sql > set autotrace on statistics ; sql > select sid, serial #, paddr from v $ session where username = user ; sid serial # paddr - - - - - - - - - - - - - - - - - - 88 93 3be2e41c 90 91 3be2e41c... sql > disconnect disconnect command in example 15 - 1 actually ends the sessions, not the connection. opening a new terminal and connecting to the instance as a different user, the query in example 15 - 2 shows that the connection from example 15 - 1 is still active. sql > connect dba1 @


has its own pga. however, the uga for a session is in the sga so that any shared server can access session data. a multiprocess oracle database uses some additional processes called background processes. the background processes perform maintenance tasks required to operate the database and to maximize performance for multiple users. each background process has a separate task, but works with the other processes. for example, the lgwr process writes data from the redo log buffer to the online redo log. when a filled log file is ready to be archived, lgwr signals another process to archive the file. oracle database creates background processes automatically when a database instance starts. an instance can have many background processes, not all of which always exist in every database configuration. the following query lists the background processes running on your database : select pname from v $ process where pname is not null order by pname ; this section includes the following topics : see also : oracle database reference for descriptions of all the background processes the mandatory background processes are present in all typical database configurations. these processes run by default in a database instance started with a minimally configured initialization parameter file ( see example 13 - 1 ). this section describes the following mandatory background processes : oracle database reference for descriptions of other mandatory processes, including mman, diag, vktm, dbrm, and psp0 oracle real application clusters administration and deployment guide and oracle clusterware administration and deployment guide for more information about background processes specific to oracle rac and oracle clusterware the process monitor ( pmon ) monitors the other background processes and performs process recovery when a server or dispatcher process terminates abnormally. pmon is responsible for cleaning up the database buffer cache and freeing resources that the client process was using. for example, pmon resets the status of the active transaction table, releases locks that are no longer required, and removes the process id from the list of active processes. pmon also registers information about the instance and dispatcher processes with the oracle net listener ( see " the oracle net listener " ). when an instance starts, pmon polls the listener to determine whether it is running. if the listener is running, then pmon passes it relevant parameters. if it is not running, then pmon periodically attempts to contact it. the system monitor process ( smon ) is in charge of a variety of system - level cleanup duties. the duties assigned to smon include : recovering terminated transactions that were skipped during instance recovery because of file - read or tablespace


a node automatically connects to other databases involved in an in - doubt distributed transaction. when reco reestablishes a connection between the databases, it automatically resolves all in - doubt transactions, removing from each database ' s pending transaction table any rows that correspond to the resolved transactions. see also : oracle database administrator ' s guide for more information about transaction recovery in distributed systems an optional background process is any background process not defined as mandatory. most optional background processes are specific to tasks or features. for example, background processes that support oracle streams advanced queuing ( aq ) or oracle automatic storage management ( oracle asm ) are only available when these features are enabled. this section describes some common optional processes : the archiver processes ( arcn ) copy online redo log files to offline storage after a redo log switch occurs. these processes can also collect transaction redo data and transmit it to standby database destinations. arcn processes exist only when the database is in archivelog mode and automatic archiving is enabled. oracle database uses job queue processes to run user jobs, often in batch mode. a job is a user - defined task scheduled to run one or more times. for example, you can use a job queue to schedule a long - running update in the background. given a start date and a time interval, the job queue processes attempt to run the job at the next occurrence of the interval. oracle database manages job queue processes dynamically, thereby enabling job queue clients to use more job queue processes when required. the database releases resources used by the new processes when they are idle. dynamic job queue processes can run a large number of jobs concurrently at a given interval. the sequence of events is as follows : the job coordinator process ( cjq0 ) is automatically started and stopped as needed by oracle scheduler ( see " oracle scheduler " ). the coordinator process periodically selects jobs that need to be run from the system job $ table. new jobs selected are ordered by time. the coordinator process dynamically spawns job queue slave processes ( jnnn ) to run the jobs. the job queue process runs one of the jobs that was selected by the cjq0 process for execution. each job queue process runs one job at a time to completion. after the process finishes execution of a single job, it polls for more jobs. if no jobs are scheduled for execution, then it enters a sleep state, from which it wakes up at periodic intervals and polls for more jobs. if the process does not find any new


table scan such as from employees, one server process performs all of the work, as shown in figure 15 - 5. in parallel execution, the server process acts as the parallel execution coordinator responsible for parsing the query, allocating and controlling the slave processes, and sending output to the user. given a query plan for a sql query, the coordinator breaks down each operator in a sql query into parallel pieces, runs them in the order specified in the query, and integrates the partial results produced by the slave processes executing the operators. figure 15 - 6 shows a parallel scan of the employees table. the table is divided dynamically ( dynamic partitioning ) into load units called granules. each granule is a range of data blocks of the table read by a single slave process, called a parallel execution server, which uses nnn as a name format. the database maps granules to execution servers at execution time. when an execution server finishes reading the rows corresponding to a granule, and when granules remain, it obtains another granule from the coordinator. this operation continues until the table has been read. the execution servers send results back to the coordinator, which assembles the pieces into the desired full table scan. the number of parallel execution servers assigned to a single operation is the degree of parallelism for an operation. multiple operations within the same sql statement all have the same degree of parallelism.


approximate of pre - cidr ( classless inter - domain routing ) subnet mask. for example : in _ addr _ t addr, mask ; addr = inet _ network ( net _ name ) ; mask = ~ ( in _ addr _ t ) 0 ; if ( ( addr & in _ classa _ net ) = = 0 ) addr < < = 8, mask < < = 8 ; if ( ( addr & in _ classa _ net ) = = 0 ) addr < < = 8, mask < < = 8 ; if ( ( addr & in _ classa _ net ) = = 0 ) addr < < = 8, mask < < = 8 ; this usage is deprecated by the cidr requirements. see fuller, v., li, t., yu, j., and varadhan, k. rfc 1519, classless inter - domain routing ( cidr ) : an address assignment and aggregation strategy. network working group. september 1993. the functions setnetent ( ), getnetent ( ), and endnetent ( ) are used to enumerate network entries from the database. setnetent ( ) sets ( or resets ) the enumeration to the beginning of the set of network entries. this function should be called before the first call to getnetent ( ). calls to getnetbyname ( ) and getnetbyaddr ( ) leave the enumeration position in an indeterminate state. if the stayopen flag is non - zero, the system may keep allocated resources such as open file descriptors until a subsequent call to endnetent ( ). successive calls to getnetent ( ) return either successive entries or null, indicating the end of the enumeration. endnetent ( ) may be called to indicate that the caller expects to do no further network entry retrieval operations ; the system may then deallocate resources it was using. it is still allowed, but possibly less efficient, for the process to call more network entry retrieval functions after calling endnetent ( ). the functions getnetbyname ( ), getnetbyaddr ( ), and getnetent ( ) use static storage that is reused in each call, making these routines unsafe for use in multi - threaded applications. the functions getnetbyname _ r ( ), getnetbyaddr _ r ( ), and getnetent _ r ( ) provide reent


is reused in each call, making these routines unsafe for use in multi - threaded applications. the functions getnetbyname _ r ( ), getnetbyaddr _ r ( ), and getnetent _ r ( ) provide reentrant interfaces for these operations. each reentrant interface performs the same operation as its non - reentrant counterpart, named by removing the ` ` _ r ' ' suffix. the reentrant interfaces, however, use buffers supplied by the caller to store returned results, and are safe for use in both single - threaded and multi - threaded applications. each reentrant interface takes the same parameters as its non - reentrant counterpart, as well as the following additional parameters. the parameter result must be a pointer to a struct netent structure allocated by the caller. on successful completion, the function returns the network entry in this structure. the parameter buffer must be a pointer to a buffer supplied by the caller. this buffer is used as storage space for the network entry data. all of the pointers within the returned struct netent result point to data stored within this buffer. see return values. the buffer must be large enough to hold all of the data associated with the network entry. the parameter buflen should give the size in bytes of the buffer indicated by buffer. for enumeration in multi - threaded applications, the position within the enumeration is a process - wide property shared by all threads. setnetent ( ) may be used in a multi - threaded application but resets the enumeration position for all threads. if multiple threads interleave calls to getnetent _ r ( ), the threads will enumerate disjointed subsets of the network database. like their non - reentrant counterparts, getnetbyname _ r ( ) and getnetbyaddr _ r ( ) leave the enumeration position in an indeterminate state. network entries are represented by the struct netent structure defined in < netdb. h >. the functions getnetbyname ( ), getnetbyname _ r, getnetbyaddr, and getnetbyaddr _ r ( ) each return a pointer to a struct netent if they successfully locate the requested entry ; otherwise they return null. the functions getnetent ( ) and getnetent _ r ( ) each return a pointer to a struct netent if they successfully enumerate an entry ;


need help using school facts jax? our quickstart video makes it easy to learn about the rich features the dashboard has to offer. you ' ll also find answers to our most frequently asked questions. for clear explanations on some of the technical terms and abbreviations, check out the glossary. glossary of terms jump to letter : - charter school ( from florida dept. of education ) charter schools are public schools that operate under a performance contract, or a " charter " which frees them from many regulations created for traditional public schools while holding them accountable for academic and financial results. charter schools are created when an individual or group submits an application to the school district ; the school district approves the application ; the applicants form a governing board that negotiates a contract with the district school board ; and the applicants and district school board agree upon a charter or contract. the district school board then becomes the sponsor of the charter school. the negotiated contract outlines expectations of both parties regarding the school ' s academic and financial charter schools are open to all students residing within the district ; however, charter schools are allowed to target students within specific age groups or grade levels, students considered at - risk of dropping out or failing, or students who meet reasonable academic, artistic or other eligibility standards established by the charter school. for more information, see fl doe office of independent education & parental - differentiated accountability differentiated accountability ( da ) refers to the system used in florida for classifying and evaluating the progress of school improvement based on school grades performance ( see " school grades " definition for more information ). beginning in 2012, florida ' s differentiated accountability assignment categories include : schools that have increased by at least one letter grade over the previous year or have maintained a school grade of " a ". reward schools are eligible for school recognition funds as an incentive for their performance. schools receiving a school grade of " c " or " d ". focus schools are subject to some increased state oversight and monitoring than reward or non - da schools. schools receiving a school grade of " f ". priority schools are subject to more intensive intervention efforts required by the florida department of education. these schools must conduct a comprehensive needs assessment and submit a plan to demonstrate significant, immediate academic and systematic improvement in areas including : school improvement planning, leadership quality, educator quality, professional development, curriculum alignment and pacing, and monitoring plans and for more information, visit fl doe bureau of school improvement. - end - of - course exams end - of - course exams ( eocs ) are standardized tests aligned with florida


mathematics, social and personal skills, science, social studies, physical development and fitness, and creative arts. - fair - k : the fair - k test is used to measure reading readiness skills, including a students ' understanding of letter names and letter - sounds ( phonemic awareness ). results from these two sections are used to calculate a student ' s probability of success in reading score. additional sections of the fair also administered to all public school kindergarten students include listening comprehension and vocabulary assessments. for more information about kindergarten readiness assessments, doe office of early learning. - magnet programs magnet programs offer a concentrated curriculum in designated areas of study, such as mathematics, science, technology, business, or performing arts. magnet programs may be offered schoolwide at dedicated magnet schools, or as special programs for magnet cohorts within traditional schools. magnet programs or schools are part of florida ' s school choice enrollment options and typically draw students from a wider geographic area than locally zoned for more information, visit fl doe magnet schools information. - postsecondary readiness postsecondary readiness rates indicate the percentage of a school ' s most recent graduating class who were qualified to enroll in college - level courses without the need for remediation in either reading or mathematics. readiness is determined by a student ' s highest scores on any of a number of recognized college placement tests, including the act, sat, cpt, or p. e. r. t. in order for a student to be considered postsecondary ready, he or she would need to meet the following minimum scores on any of these - act ( potential score range : 1 - 36 ) : - reading : 18 - english : 17 - mathematics : 19 - cpt ( potential score range : 1 - 120 ) : - writing skills : - elementary algebra : - p. e. r. t. ( potential score range : 50 - 150 ) : - reading : 104 - writing : 99 - mathematics : 113 - sat ( potential score range : 200 - 800 ) : - verbal : 440 - mathematics : 440 for more information about these tests or how postsecondary readiness is calculated, visit fl doe college and career readiness. - school grades school grades are the commonly used term to refer to a school ' s state accountability rating. all eligible public schools in florida are evaluated each year on student performance in the following - reading performance ( all students ) - reading performance gains ( all students ) - reading performance gains ( lowest 25 % students ) - math performance ( all students ) - math performance gains (


science supplies and services model for mass spectrometer how many of high school or college students have seen the insides of a working mass spectrometer? how many know how and why it works? what is it used for? is the print - out the only important feature of the instrument or should our students understand how the information was obtained? a model of a mass spectrometer can be used to encourage this understanding. the s17 science model mass spectrometer is designed to answer an number of questions, and to teach a number of very interesting concepts. the instruction sheets that accompany this kit outline, in great detail, some of the best ways of using this kit to : the instruction sheets include information and diagrams to help you set up the apparatus. a set of sample questions, comments and answers that have been elicited and used in various classrooms is also included. students in kindergarten through college have marveled at the use of this kit in demonstrations. the kit has already been purchased by high schools and universities throughout the world for demonstrating the mass spectrometer to students of all academic backgrounds. you will want one of these in your school. it is available in two different kits, eq 129 and eq 131. the instructions sheets are the same in both kits. your ip address is : 220. 127. 116. 11


open version of the diphthong rather than the existence of a diphthong in contrast to a monophthong. for example, someone pronouncing the " long e " as / eɪ / might refer to / ɛɪ / and / aɪ / as " diphthongs " but consider / eɪ / a " normal e ". the following is not a complete depiction of all sounds in all dialects but is an exemplative overview. | ⟨ a ⟩ | | / a / or / ɒ / | | / oɒ / | | / aː / or / ɒː / | | ⟨ e ⟩ | | / ɛ / | | / eɪ / or / ɛɪ / | | / ɛː / | | ⟨ o ⟩ | | / ɔ / | | / oʊ / or / ɔʊ / | | / ɔː / | | ⟨ o ⟩ ( and other spellings ) | | / œ / | | / / or / / | | / œː / | some of the sound - long vowels have had special characters in some areas or in the writing of some authors. the most widespread are " e " for / ɛː /, " æ " for / / ( and to a much lesser extent for / œː / ) and " œ " for / œː /. " a " has been used for both / ɛː / and / /. key to dialectal pronunciation in general, the most closed version ( on the left ) is spoken in the west ( e. g. lower saxony ), while the most open ( on the right ) versions are from the east, especially rural ( not urban ) parts of w : mecklenburg - vorpommern. e = / ɛɪ / = / eɪ / ~ / ɛɪ / ~ / aɪ / o = / ɔʊ / = / oʊ / ~ / ɔʊ / ~ / ɒʊ / o = / / = / / ~ / / ~ / / ; [ eɪ ] ( w : konigsberg, low prussian ) u etc. ( long ) = / yː / ; [ iː ] ( low prussian ) u etc. ( short ) = [ ] ; [ ɪ ] ( low prussian ) r = / r / = [ r ] ~ [ ɾ ] ( except in syllable coda ) a = / ʌ / = [ a ] ~ [ æ ] ~ [ ʌ ] ~ [ ɒ ] the


; [ ɪ ] ( low prussian ) r = / r / = [ r ] ~ [ ɾ ] ( except in syllable coda ) a = / ʌ / = [ a ] ~ [ æ ] ~ [ ʌ ] ~ [ ɒ ] the merger of monophthongal a and o due to the relative similarity of the sounds of lengthened a and lengthened o, both were used somewhat interchangeably in middle low german writing. later, " a " replaced the letter " o " in the quasi - standard that middle low german had developed. this was because, at some point in history, most low german dialects merged the sound - long a with the sound - long o. later many merged the long a with the sound - long a as well. which sound was kept and which was lost was random throughout the dialects. in addition, low german orthography became more varied and also more randomized in later periods, so that words might be written with either a or o in a region ( e. g. apen and open ), while not necessarily giving away the pronunciation. comparison of low german and dutch low saxon orthographies some important differences between dutch - influenced orthography of dutch low saxon and the german - influences orthography of low german pertain to the representation of the following : | ipa / s / | | s | | s, ss, ß, z | | ipa / ø /, / œ / | | eu | | o ( rarely æ for / œ / ) | | vowel length in closed syllables | | doubled vowel | | doubled consonant or h | | capitalisation of nouns | | no | | yes | - for example, compare dutch low saxon zes ( “ six ” ) and kruus ( “ cross ” ) with german low german sess ( “ six ” ) and kruuz ( “ cross ” ). - dutch speakers usually use a double vowel ( laand ) to show the length of a vowel in a closed syllable, german speakers use an h ( wahnen ). both use an e after an i. the difference can be seen in the spellings of the word which means " year ", which is pronounced either / jɒːɾ / or / jɔːɾ / or with / - ɐ / instead of / ɾ / : it is written as jaar and joar in dutch low saxon, but as jahr, johr or some variant thereof in germany. - influenced by standard high german, which capitalizes nouns


| | this article needs additional citations for verification. ( april 2008 ) | a blackboard ( uk english ) or chalkboard ( us english ) is a reuseable writing surface on which text or drawings are made with sticks of calcium sulfate or calcium carbonate, known, when used for this purpose, as chalk. blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. modern versions are often green because the color is considered easier on the eyes. a blackboard can simply be a piece of board painted with matte dark paint ( usually black or dark green ). a more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. the highest grade blackboards are made of a rougher version porcelain enamelled steel ( black, green, blue or sometimes other colours ). porcelain is very hard wearing and blackboards made of porcelain usually last 10 – 20 years in intensive use. lecture theatres may contain a number of blackboards in a grid arrangement. the lecturer then moves boards into reach for writing and then move them out of reach, allowing a large amount of material to be shown simultaneously. the chalk marks can be easily wiped off with a damp cloth, a sponge or a special blackboard eraser consisting of a block of wood covered by a felt pad. however, chalk marks made on some types of wet blackboard can be difficult to remove. blackboard manufacturers often advise that a new or newly resurfaced blackboard be completely covered using the side of a stick of chalk and then that chalk brushed off as normal to prepare it for use. chalk sticks sticks of processed " chalk " are produced especially for use with blackboards in white and also in various colours. these are not actually made from chalk rock but from calcium sulfate in its dihydrate form, gypsum. advantages and disadvantages as compared to whiteboards, blackboards have a variety of advantages : - chalk requires no special care ; whiteboard markers must be capped or else they dry out. - chalk is an order of magnitude cheaper than whiteboard markers for a comparable amount of writing. - it is easier to draw lines of different weights and thicknesses with chalk than with whiteboard markers. - chalk has a mild smell, whereas whiteboard markers often have a pungent odor. - chalk writing often provides better contrast than whiteboard markers. on the other hand, chalk produces dust, the amount depending on the quality of chalk used


a textbook or coursebook is a manual of instruction in any branch of study. textbooks are produced according to the demands of educational institutions. although most textbooks are only published in printed format, many are now available as online electronic books and increasingly, although illegally, in scanned format on file sharing networks. the ancient greeks wrote texts intended for education. the modern textbook has its roots in the standardization made possible by the printing press. johannes gutenberg himself may have printed editions of ars minor, a schoolbook on latin grammar by aelius donatus. early textbooks were used by tutors and teachers, who used the books as instructional aids ( e. g., alphabet books ), as well as individuals who taught themselves. the greek philosopher socrates ( 469 - 399 b. c. ) lamented the loss of knowledge because the media of transmission were changing. before the invention of the greek alphabet 2, 500 years ago, knowledge and stories were recited aloud, much like homer ' s epic poems. the new technology of writing meant stories no longer needed to be memorized, a development socrates feared would weaken the greeks ' mental capacities for memorizing and retelling. ( paradoxically, we know about socrates ' concerns only because they were written down by his student plato in his famous dialogues. ) the next revolution for books came with the 15th - century invention of printing with changeable type. the invention is attributed to german metalsmith johannes gutenberg, who cast type in molds using a melted metal alloy and constructed a wooden - screw printing press to transfer the image onto paper. gutenberg ' s first and only large - scale printing effort was the now iconic gutenberg bible in the 1450s — a latin translation from the hebrew old testament and the greek new testament [ disambiguation needed ], copies of which can be viewed on the british library website www. bl. uk. gutenberg ' s invention made mass production of texts possible for the first time. although the gutenberg bible itself was stratospherically expensive, printed books began to spread widely over european trade routes during the next 50 years, and by the 16th century printed books had become more widely accessible and less costly. compulsory education and the subsequent growth of schooling in europe led to the printing of many standardized texts for children. textbooks have become the primary teaching instrument for most children since the 19th century. two textbooks of historical significance in united states schooling were the 18th century new england primer and the 19th century mcguffey readers. technological advances change the way people


for children. textbooks have become the primary teaching instrument for most children since the 19th century. two textbooks of historical significance in united states schooling were the 18th century new england primer and the 19th century mcguffey readers. technological advances change the way people interact with textbooks. online and digital materials are making it increasingly easy for students to access materials other than the traditional print textbook. students now have access to electronic and pdf books, online tutoring systems and video lectures. an example of e - book publishing is principles of biology from nature publishing. most notably, an increasing number of authors are foregoing commercial publishers and offering their textbooks under a creative commons or other open license. the new york times recently endorsed the use of free, open, digital textbooks in the editorial " that book costs how much? " the " broken market " the textbook market does not operate in exactly the same manner as most consumer markets. first, the end consumers ( students ) do not select the product, and the product is not purchased by faculty or professors. therefore, price is removed from the purchasing decision, giving the producer ( publishers ) disproportionate market power to set prices high. similarities are found in the pharmaceutical industry, which sells its wares to doctors, rather than the ultimate end - user ( i. e. patient ). this fundamental difference in the market is often cited as the primary reason that prices are out of control. the term " broken market " first appeared in economist james koch ' s analysis of the market commissioned by the advisory committee on student financial assistance. this situation is exacerbated by the lack of competition in the textbook market. consolidation in the past few decades [ when? ] has reduced the number of major textbook companies from around 30 to just a handful. consequently, there is less competition than there used to be, and the high cost of starting up ' keeps new companies from entering. new editions & the used book market students seek relief from rising prices through the purchase of used copies of textbooks, which tend to be less expensive. most college bookstores offer used copies of textbooks at lower prices. most bookstores will also buy used copies back from students at the end of a term if the book is going to be re - used at the school. books that are not being re - used at the school are often purchased by an off - campus wholesaler for 0 - 30 % of the new cost, for distribution to other bookstores where the books will be sold. textbook companies have countered this by encouraging faculty to assign homework that


one - time - use supplements destroy the resale value of the textbook. according to the student pirgs, the typical bundled textbook is 10 % - 50 % more than an unbundled textbook, and 65 % of professors said they “ rarely ” or “ never ” use the bundled items in their courses. a 2005 government accountability office ( gao ) report found that the production of these supplemental items was the primary cause of rapidly increasing prices : while publishers, retailers, and wholesalers all play a role in textbook pricing, the primary factor contributing to increases in the price of textbooks has been the increased investment publishers have made in new products to enhance instruction and learning... while wholesalers, retailers, and others do not question the quality of these materials, they have expressed concern that the publishers ’ practice of packaging supplements with a textbook to sell as one unit limits the opportunity students have to purchase less expensive used books.... if publishers continue to increase these investments, particularly in technology, the cost to produce a textbook is likely to continue to increase in the future. bundling has also been used as a means of segmenting the used book market. each combination of a textbook and supplemental items receives a separate isbn. a single textbook could therefore have dozens of isbns that denote different combinations of supplements packaged with that particular book. when a bookstore attempts to track down used copies of textbooks, they will search for the isbn the course instructor orders, which will locate only a subset of the copies of the textbook. legislation on the state and federal level seeks to limit the practice of bundling, by requiring publishers to offer all components separately. publishers have testified in favor of bills including this provision, but only in the case that the provision exempts the loosely defined category of " integrated textbooks. " the federal bill only exempts 3rd party materials in integrated textbooks, however publisher lobbyists have attempted to create a loophole through this definition in state bills. price disclosure given that the problem of high textbook prices is linked to the " broken " economics of the market, requiring publishers to disclose textbook prices to faculty is a solution pursued by a number of legislatures. by inserting price into sales interactions, this regulation will supposedly make the economic forces operate more normally. no data suggests that this is in fact true. however, the student pirgs have found that publishers actively withhold pricing information from faculty, making it difficult to obtain. their most recent study found that 77 % of faculty say publisher sales representatives do not volunteer prices, and only 40 % got an answer when


state policies suggest that public investment in open textbooks might make sense. to offer another perspective, any jurisdiction might find itself challenged to find sufficient numbers of credible academics who would be willing to undertake the effort of creating an open textbook without realistic compensation, in order to make such a proposal work. the other challenge involves the reality of publishing, which is that textbooks with good sales and profitability subsidize the creation and publication of low demand but believed to be necessary textbooks. subsidies skew markets and the elimination of subsidies is disruptive ; in the case of low demand textbooks the possibilities following subsidy removal include any or all of the following : higher retail prices, a switch to open textbooks, a reduction of the number of titles published. on the other hand, independent open textbook authoring and publishing models are developing. most notably, the startup publisher flat world knowledge already has dozens of college - level open textbooks that are used by more than 900 institutions in 44 countries. their innovative business model was to offer the open textbook free online, and then sell ancillary products that students are likely to buy if prices are reasonable - print copies, study guides, epub,. mobi ( kindle ), pdf download, etc. flat world knowledge compensates its authors with royalties on these sales. with the generated revenue flat world knowledge funded high - quality publishing activities with a goal of making the flat world financial model sustainable. however, in january, 2013 flat world knowledge announced their financial model could no longer sustain their free - to - read options for students. flat world knowledge intends to have open textbooks available for the 125 highest - enrolled courses on college campuses within the next few years. ck - 12 flexbooks are the open textbooks designed for united states k - 12 courses. ck - 12 flexbooks are designed to facilitate conformance to national and united states and individual state textbook standards. ck - 12 flexbooks are licensed under a creative commons by - nc - sa license, are easy to update, and easy to customize. ck - 12 flexbooks are free to use online and offer formats suitable for use on portable personal reading devices and computers - both online and offline. formats for both ipad and kindle are offered. school districts may select a title as is or customize the open textbook to meet local instructional standards. the file may be then accessed electronically or printed using any print on demand service without paying a royalty, saving 80 % or more when compared to traditional textbook options. an example print on demand open textbook title, " college algebra " by stitz


in some situations. although the project does not permit verbatim copies of pre - existing works ( those would be covered by wikisource ), it does permit annotated texts, which are a kind of text that includes an original text within it and serves as a guide to reading or studying that text. annotated editions of previously published source texts may only be written if the source text is compatible with the project ' s license. mit opencourseware provides several open textbooks. international market pricing similar to the issue of reimportation of pharmaceuticals into the u. s. market, the gao report also highlights a similar phenomenon in textbook distribution. retailers and publishers have expressed concern about the reimportation of lower - priced textbooks from international locations. specifically, they cited the ability students have to purchase books from online distribution channels outside the united states at lower prices, which may result in a loss of sales for u. s. retailers. additionally, the availability of lower - priced textbooks through these channels has heightened distrust and frustration among students regarding textbook prices, and college stores find it difficult to explain why their textbook prices are higher, according to the national association of college stores. retailers and publishers have also been concerned that some u. s. retailers may have engaged in reimportation on a large scale by ordering textbooks for entire courses at lower prices from international distribution channels. while the 1998 supreme court decision quality king v. l ' anza protects the reimportation of copyrighted materials under the first - sale doctrine, textbook publishers have still attempted to prevent the u. s. sale of international editions by enforcing contracts which forbid foreign wholesalers from selling to american distributors. concerned about the effects of differential pricing on college stores, the national association of college stores has called on publishers to stop the practice of selling textbooks at lower prices outside the united states. for example, some u. s. booksellers arrange for drop - shipments in foreign countries which are then re - shipped to america where the books can be sold online at used prices ( for a " new " unopened book ). the authors often getting half - royalties instead of full - royalties, minus the charges for returned books from bookstores. cost distribution according to the national association of college stores, the entire cost of the book is justified by expenses, with typically 11. 7 % of the price of a new book going to the author ' s royalties ( or a committee of editors at the publishing house ), 22. 7 % going to the store,


textbooks. discussions of textbooks have been included on creation and evolution in the public education debate. the smith v. board of school commissioners of mobile county case brought forward a debate about scientific fact being presented in textbooks. in his book, surely you ' re joking, mr. feynman!, the late physics nobel prize laureate richard p. feynman described his experiences as a member of a committee that evaluated science textbooks. at some instances, there were nonsensical examples to illustrate physical phenomena ; then a company sent — for reasons of timing — a textbook that contained blank pages, which even got good critiques. feynman himself experienced attempts at bribery. largely in the us, but increasingly in other nations, k - 12 mathematics textbooks have reflected the controversies of new math and reform mathematics which have sought to replace traditional mathematics in what have been called the math wars. traditional texts, still favored in asia and other areas, merely taught the same time - tested mathematics that most adults have learned. by contrast " progressive " approaches seek to address problems in social inequity with approaches that often incorporate principles of constructivism and discovery. texts such as terc and cmp discourage or omit standard mathematics methods and concepts such as long division and lowest common denominators. for example an index entry to multiply fractions would lead to " devise your own method to multiply fractions which work on these examples ", and the formula for the area of a circle would be an exercise for a student to derive rather than including it in the student text. by the 2000s, while some districts were still adopting the more novel methods, others had abandoned them as unworkable. higher education in the u. s., college and university textbooks are chosen by the professor teaching the course, or by the department as a whole. students are typically responsible for obtaining their own copies of the books used in their courses, although alternatives to owning textbooks, such as textbook rental services and library reserve copies of texts, are available in some instances. in some european countries, such as sweden or spain, students attending institutions of higher education pay for textbooks themselves, although higher education is free of charge otherwise. with higher education costs on the rise, many students are becoming sensitive to every aspect of college pricing, including textbooks, and in many cases amount to one tenth of tuition costs. the 2005 government accountability office report on college textbooks said that since the 1980s, textbook and supply prices have risen twice the rate of inflation in the past two decades. a 2005 pi


##rgs ( press release ) - see pirg ' s catalog of open textbooks for examples of open textbooks - a cover to cover solution by nicole allen of the student pirgs. 2010. - flat world knowledge president eric frank addresses oregon legislators on solving textbook affordability. pressitt. february 21, 2011. - open - source textbook co. flat world goes back to school with 40, 000 new customers - venture beat 8 / 20 / 09 - 150, 000 college students save $ 12 million using flat world knowledge open textbooks. marketwire. august 23, 2010. - flat world knowledge : open college textbooks by sanford forte. opensource. com. february 23, 2010. - organizational behavior v1. 1 by talya bauer & berrin erdogan. irvington, ny : flat world knowledge. 2010. ( free online open textbook format sample - pdf view ) - introduction to psychology by charles stangor. irvington, ny : flat world knowledge. 2010. ( free online open textbook format sample - web view ) - see flat world knowledge ' s website - flat world knowledge website. - flat world knowledge gets $ 15 million in funding. publishers weekly. january 20, 2011. - ck - 12 flexbooks. homepage. - carl stitz / jeff zeager on ohio textbook hq 2010. - ck - 12 - standards correlations united states. - human biology - genetics ck - 12 flexbook by the program in human biology, stanford university. ( sample of free web access format ) - about ck - 12 foundation - curriki. org homepage. - lewin, tamar ( 21 october 2003 ). " students find $ 100 textbooks cost $ 50, purchased overseas ". the new york times. retrieved 24 september 2009. - " testimony of marc l. fleischaker, counsel, national association of college stores ". hearing on " are college textbooks priced fairly? ". u. s. house of representatives, committee on education and the workforce, subcommittee on 21st century competitiveness. 20 july 2004. archived from the original on 7 october 2011. retrieved 24 september 2009. - rip - off 101 : second edition, the student pirgs ( 2005 ) further reading - slatalla, michelle ( august 30, 2007 ), " knowledge is priceless but textbooks are not ", new york times. | wikimedia commons has media related to : textbooks |


hydrothermal circulation in its most general sense is the circulation of hot water ; ' hydros ' in the greek meaning water and ' thermos ' meaning heat. hydrothermal circulation occurs most often in the vicinity of sources of heat within the earth ' s crust. this generally occurs near volcanic activity, but can occur in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. seafloor hydrothermal circulation the term includes both the circulation of the well known, high temperature vent waters near the ridge crests, and the much lower temperature, diffuse flow of water through sediments and buried basalts further from the ridge crests. the former circulation type is sometimes termed " active ", and the latter " passive ". in both cases the principle is the same : cold dense seawater sinks into the basalt of the seafloor and is heated at depth whereupon it rises back to the rock - ocean water interface due to its lesser density. the heat source for the active vents is the newly formed basalt, and, for the highest temperature vents, the underlying magma chamber. the heat source for the passive vents is the still - cooling older basalts. heat flow studies of the seafloor suggest that basalts within the oceanic crust take millions of years to completely cool as they continue to support passive hydrothermal circulation systems. hydrothermal vents are locations on the seafloor where hydrothermal fluids mix into the overlying ocean. perhaps the best known vent forms are the naturally - occurring chimneys referred to as black smokers. hydrothermal circulation is not limited to ocean ridge environments. the source water for hydrothermal explosions, geysers and hot springs is heated groundwater convecting below and lateral to the hot water vent. hydrothermal circulating convection cells exist any place an anomalous source of heat, such as an intruding magma or volcanic vent, comes into contact with the groundwater system. deep crust hydrothermal also refers to the transport and circulation of water within the deep crust, generally from areas of hot rocks to areas of cooler rocks. the causes for this convection can be : - intrusion of magma into the crust - radioactive heat generated by cooled masses of granite - heat from the mantle - hydraulic head from mountain ranges, for example, the great artesian basin - dewatering of metamorphic rocks which liberates water - dewatering of deeply buried sediments hydrothermal ore deposits during the early 1900s various geologists worked to classify hydrothermal ore deposits which were assumed to have formed from upward flowing aque


- dewatering of metamorphic rocks which liberates water - dewatering of deeply buried sediments hydrothermal ore deposits during the early 1900s various geologists worked to classify hydrothermal ore deposits which were assumed to have formed from upward flowing aqueous solutions. waldemar lindgren developed a classification based on interpreted decreasing temperature and pressure conditions of the depositing fluid. his terms : hypothermal, mesothermal, epithermal and teleothermal were based on decreasing temperature and increasing distance from a deep source. only the epithermal has been used in recent works. john guilbert ' s 1985 redo of lindgren ' s system for hydrothermal deposits includes the following : - ascending hydrothermal fluids, magmatic or meteoric water - porphyry copper and other deposits, 200 - 800 °c, moderate pressure - igneous metamorphic, 300 - 800 °c, low - moderate pressure - cordilleran veins, intermediate to shallow depths - epithermal, shallow to intermediate, 50 - 300 °c, low pressure - circulating heated meteoric solutions - circulating heated seawater - oceanic ridge deposits, 25 - 300 °c, low pressure see also - w. lindgren, 1933, mineral deposits, mcgraw hill, 4th ed. - guilbert, john m. and charles f. park, jr., 1986, the geology of ore deposits, freeman, p. 302 isbn 0 - 7167 - 1456 - 6


phosphorescence is a specific type of photoluminescence related to fluorescence. unlike fluorescence, a phosphorescent material does not immediately re - emit the radiation it absorbs. the slower time scales of the re - emission are associated with " forbidden " energy state transitions in quantum mechanics. as these transitions occur very slowly in certain materials, absorbed radiation may be re - emitted at a lower intensity for up to several hours after the original excitation. commonly seen examples of phosphorescent materials are the glow - in - the - dark toys, paint, and clock dials that glow for some time after being charged with a bright light such as in any normal reading or room light. typically the glowing then slowly fades out within minutes ( or up to a few hours ) in a dark room. the study of phosphorescent materials led to the discovery of radioactivity in 1896. in simple terms, phosphorescence is a process in which energy absorbed by a substance is released relatively slowly in the form of light. this is in some cases the mechanism used for " glow - in - the - dark " materials which are " charged " by exposure to light. unlike the relatively swift reactions in a common fluorescent tube, phosphorescent materials used for these materials absorb the energy and " store " it for a longer time as the processes required to re - emit the light occur less often. quantum mechanical most photoluminescent events, in which a chemical substrate absorbs and then re - emits a photon of light, are fast, on the order of 10 nanoseconds. light is absorbed and emitted at these fast time scales in cases where the energy of the photons involved matches the available energy states and allowed transitions of the substrate. in the special case of phosphorescence, the absorbed photon energy undergoes an unusual intersystem crossing into an energy state of higher spin multiplicity ( see term symbol ), usually a triplet state. as a result, the energy can become trapped in the triplet state with only classically " forbidden " transitions available to return to the lower energy state. these transitions, although " forbidden ", will still occur in quantum mechanics but are kinetically unfavored and thus progress at significantly slower time scales. most phosphorescent compounds are still relatively fast emitters, with triplet lifetimes on the order of milliseconds. however, some compounds have triplet lifetimes up to minutes or even


thus progress at significantly slower time scales. most phosphorescent compounds are still relatively fast emitters, with triplet lifetimes on the order of milliseconds. however, some compounds have triplet lifetimes up to minutes or even hours, allowing these substances to effectively store light energy in the form of very slowly degrading excited electron states. if the phosphorescent quantum yield is high, these substances will release significant amounts of light over long time scales, creating so - called " glow - in - the - dark " materials. where s is a singlet and t a triplet whose subscripts denote states ( 0 is the ground state, and 1 the excited state ). transitions can also occur to higher energy levels, but the first excited state is denoted for simplicity. some examples of " glow - in - the - dark " materials do not glow by phosphorescence. for example, " glow sticks " glow due to a chemiluminescent process which is commonly mistaken for phosphorescence. in chemiluminescence, an excited state is created via a chemical reaction. the light emission tracks the kinetic progress of the underlying chemical reaction. the excited state will then transfer to a " dye " molecule, also known as a sensitizer or fluorophor, and subsequently fluoresce back to the ground state common pigments used in phosphorescent materials include zinc sulfide and strontium aluminate. use of zinc sulfide for safety related products dates back to the 1930s. however, the development of strontium aluminate, with a luminance approximately 10 times greater than zinc sulfide, has relegated most zinc sulfide based products to the novelty category. strontium aluminate based pigments are now used in exit signs, pathway marking, and other safety related signage. | this section requires expansion. ( october 2008 ) | see also - karl a. franz, wolfgang g. kehr, alfred siggel, jurgen wieczoreck, and waldemar adam " luminescent materials " in ullmann ' s encyclopedia of industrial chemistry 2002, wiley - vch, weinheim. doi : 10. 1002 / 14356007. a15 _ 519 - zitoun, d. ; bernaud, l. ; manteghetti, a. microwave synthesis of a long - lasting phosphor. j. chem. ed. 2009, 86, 72 -


affects the sound according to many players, is not generally agreed. any of the following can be called semi - acoustic : - instruments starting from a solid body " blank " which has been routed out to make a chambered body guitar. - instruments with semi - hollow bodies constructed from plates of wood around a solid core, having no soundholes, such as the gibson lucille or brian may red special. - instruments with a solid core but hollow bouts and soundholes ( usually f - holes ), such as the gibson es - 335. in these, the bridge is fixed to a solid block of wood rather than to a sounding board, and the belly vibration is minimised much as in a solid body instrument. - thin - bodied archtop guitars, such as the epiphone casino. these possess both a sounding board and sound box, but the function of these is purely to modify the sound transmitted to the pickups. such guitars are still intended purely as electric instruments, and while they do make some sound when the pickups are not used, the tone is weak and not normally considered musically useful. - full hollowbody semi - acoustic instruments, often called jazz guitars, such as the gibson es - 175 ; these have a full - size sound box, but are still intended to be played through an amplifier. the rickenbacker 330 jg some companies that have produced famous semi - acoustic guitars include : gibson, gretsch and rickenbacker. a variety of manufacturers now produce semi - acoustic model guitars : d ' angelico, epiphone, ibanez, etc. - fully hollow body - thinline hollow body ( thin body ) - semi hollow body ( with center block ) - other semi hollow ( solid - body with cavities ) - various types - archtop guitars. guitars with a fully hollow or semi - hollow body, with or without pickups. - electro - acoustic guitars. fully acoustic guitars with piezo pickups. - hybrid guitars. guitars with both magnetic and piezo pickups. can be solid, semi - hollow or hollow bodied. - silent guitars. solid body guitars with a piezo pickups. - ingram, adrian, a concise history of the electric guitar, melbay, 2001. - hunter, dave, the rough guide to guitar, penguin books, 2011. - miller, a. j., the electric guitar : a history of an american icon, baltimore, md, smithsonian institute, 2004. - martin a. darryl, innovation and the development of the modern


| quantum field theory | | | it has been suggested that this article be merged with zero - point energy. ( discuss ) proposed since june 2012. | in quantum field theory, the vacuum state ( also called the vacuum ) is the quantum state with the lowest possible energy. generally, it contains no physical particles. zero - point field is sometimes used [ by whom? ] as a synonym for the vacuum state of an individual quantized field. according to present - day understanding of what is called the vacuum state or the quantum vacuum, it is " by no means a simple empty space ", and again : " it is a mistake to think of any physical vacuum as some absolutely empty void. " according to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of existence. the qed vacuum of quantum electrodynamics ( or qed ) was the first vacuum of quantum field theory to be developed. qed originated in the 1930s, and in the late 1940s and early 1950s it was reformulated by feynman, tomonaga and schwinger, who jointly received the nobel prize for this work in 1965. today the electromagnetic interactions and the weak interactions are unified in the theory of the electroweak interaction. the standard model is a generalization of the qed work to include all the known elementary particles and their interactions ( except gravity ). quantum chromodynamics is the portion of the standard model that deals with strong interactions, and qcd vacuum is the vacuum of quantum chromodynamics. it is the object of study in the large hadron collider and the relativistic heavy ion collider, and is related to the so - called vacuum structure of strong interactions. non - zero expectation value if the quantum field theory can be accurately described through perturbation theory, then the properties of the vacuum are analogous to the properties of the ground state of a quantum mechanical harmonic oscillator ( or more accurately, the ground state of a qm problem ). in this case the vacuum expectation value ( vev ) of any field operator vanishes. for quantum field theories in which perturbation theory breaks down at low energies ( for example, quantum chromodynamics or the bcs theory of superconductivity ) field operators may have non - vanishing vacuum expectation values called condensates. in the standard model, the non - zero vacuum expectation value of the higgs field, arising from spontaneous symmetry


a field φ, which should be written as, is usually condensed to. virtual particles the presence of virtual particles can be rigorously based upon the non - commutation of the quantized electromagnetic fields. non - commutation means that although the average values of the fields vanish in a quantum vacuum, their variances do not. the term " vacuum fluctuations " refers to the variance of the field strength in the minimal energy state, and is described picturesquely as evidence of " virtual particles ". it is sometimes attempted to provide an intuitive picture of virtual particles based upon the heisenberg energy - time uncertainty principle : ( with δe and δt being the energy and time variations respectively ; δe is the accuracy in the measurement of energy and δt is the time taken in the measurement, and ħ is the planck constant divided by 2π ) arguing along the lines that the short lifetime of virtual particles allows the " borrowing " of large energies from the vacuum and thus permits particle generation for short times. although the phenomenon of virtual particles is accepted, this interpretation of the energy - time uncertainty relation is not universal. one issue is the use of an uncertainty relation limiting measurement accuracy as though a time uncertainty δt determines a " budget " for borrowing energy δe. another issue is the meaning of " time " in this relation, because energy and time ( unlike position q and momentum p, for example ) do not satisfy a canonical commutation relation ( such as [ q, p ] = i ħ ). various schemes have been advanced to construct an observable that has some kind of time interpretation, and yet does satisfy a canonical commutation relation with energy. the very many approaches to the energy - time uncertainty principle are a long and continuing subject. physical nature of the quantum vacuum according to astrid lambrecht ( 2002 ) : " when one empties out a space of all matter and lowers the temperature to absolute zero, one produces in a gedankenexperiment the quantum vacuum state. " photon - photon interaction can occur only through interaction with the vacuum state of some other field, for example through the dirac electron - positron vacuum field ; this is associated with the concept of vacuum polarization. according to milonni ( 1994 ) : "... all quantum fields have zero - point energies and vacuum fluctuations. " this means that there is a component of the quantum vacuum respectively for each component field ( considered in the conceptual absence of the other fields ), such as the electromagnetic field, the dirac electron


quantum fields have zero - point energies and vacuum fluctuations. " this means that there is a component of the quantum vacuum respectively for each component field ( considered in the conceptual absence of the other fields ), such as the electromagnetic field, the dirac electron - positron field, and so on. according to milonni ( 1994 ), some of the effects attributed to the vacuum electromagnetic field can have several physical interpretations, some more conventional than others. the casimir attraction between uncharged conductive plates is often proposed as an example of an effect of the vacuum electromagnetic field. schwinger, deraad, and milton ( 1978 ) are cited by milonni ( 1994 ) as validly, though unconventionally, explaining the casimir effect with a model in which " the vacuum is regarded as truly a state with all physical properties equal to zero. " in this model, the observed phenomena are explained as the effects of the electron motions on the electromagnetic field, called the source field effect. milonni writes : " the basic idea here will be that the casimir force may be derived from the source fields alone even in completely conventional qed,... " milonni provides detailed argument that the measurable physical effects usually attributed to the vacuum electromagnetic field cannot be explained by that field alone, but require in addition a contribution from the self - energy of the electrons, or their radiation reaction. he writes : " the radiation reaction and the vacuum fields are two aspects of the same thing when it comes to physical interpretations of various qed processes including the lamb shift, van der waals forces, and casimir effects. " this point of view is also stated by jaffe ( 2005 ) : " the casimir force can be calculated without reference to vacuum fluctuations, and like all other observable effects in qed, it vanishes as the fine structure constant, α, goes to zero. " see also references and notes - astrid lambrecht ( hartmut figger, dieter meschede, claus zimmermann eds. ) ( 2002 ). observing mechanical dissipation in the quantum vacuum : an experimental challenge ; in laser physics at the limits. berlin / new york : springer. p. 197. isbn 3 - 540 - 42418 - 0. - christopher ray ( 1991 ). time, space and philosophy. london / new york : routledge. chapter 10, p. 205. isbn 0 - 415 - 03221 - 0. - aip physics news update, 1996 - physical review focus dec. 1998 - walter dittrich & gi


and philosophy. london / new york : routledge. chapter 10, p. 205. isbn 0 - 415 - 03221 - 0. - aip physics news update, 1996 - physical review focus dec. 1998 - walter dittrich & gies h ( 2000 ). probing the quantum vacuum : perturbative effective action approach. berlin : springer. isbn 3 - 540 - 67428 - 4. - for an historical discussion, see for example ari ben - menahem, ed. ( 2009 ). " quantum electrodynamics ( qed ) ". historical encyclopedia of natural and mathematical sciences, volume 1 ( 5th ed. ). springer. pp. 4892 ff. isbn 3 - 540 - 68831 - 5. for the nobel prize details and the nobel lectures by these authors see " the nobel prize in physics 1965 ". nobelprize. org. retrieved 2012 - 02 - 06. - jean letessier, johann rafelski ( 2002 ). hadrons and quark - gluon plasma. cambridge university press. p. 37 ff. isbn 0 - 521 - 38536 - 9. - sean carroll, sr research associate - physics, california institute of technology, june 22, 2006 c - span broadcast of cosmology at yearly kos science panel, part 1 - david delphenich ( 2006 ). " nonlinear electrodynamics and qed ". arxiv : hep - th / 0610088 [ hep - th ]. - klein, james j. and b. p. nigam, birefringence of the vacuum, physical review vol. 135, p. b1279 - b1280 ( 1964 ). - mourou, g. a., t. tajima, and s. v. bulanov, optics in the relativistic regime ; § xi nonlinear qed, reviews of modern physics vol. 78 ( no. 2 ), 309 - 371 ( 2006 ) pdf file. - holger gies ; joerg jaeckel ; andreas ringwald ( 2006 ). " polarized light propagating in a magnetic field as a probe of millicharged fermions ". physical review letters 97 ( 14 ). arxiv : hep - ph / 0607118. bibcode : 2006phrvl.. 97n0402g. doi : 10. 1103 / physrevlett.


( 14 ). arxiv : hep - ph / 0607118. bibcode : 2006phrvl.. 97n0402g. doi : 10. 1103 / physrevlett. 97. 140402. - davis ; joseph harris ; gammon ; smolyaninov ; kyuman cho ( 2007 ). " experimental challenges involved in searches for axion - like particles and nonlinear quantum electrodynamic effects by sensitive optical techniques ". arxiv : 0704. 0748 [ hep - th ]. - myron wyn evans, stanisław kielich ( 1994 ). modern nonlinear optics, volume 85, part 3. john wiley & sons. p. 462. isbn 0 - 471 - 57548 - 8. " for all field states that have classical analog the field quadrature variances are also greater than or equal to this commutator. " - david nikolaevich klyshko ( 1988 ). photons and nonlinear optics. taylor & francis. p. 126. isbn 2 - 88124 - 669 - 9. - milton k. munitz ( 1990 ). cosmic understanding : philosophy and science of the universe. princeton university press. p. 132. isbn 0 - 691 - 02059 - 0. " the spontaneous, temporary emergence of particles from vacuum is called a " vacuum fluctuation ". " - for an example, see p. c. w. davies ( 1982 ). the accidental universe. cambridge university press. p. 106. isbn 0 - 521 - 28692 - 1. - a vaguer description is provided by jonathan allday ( 2002 ). quarks, leptons and the big bang ( 2nd ed ed. ). crc press. pp. 224 ff. isbn 0 - 7503 - 0806 - 0. " the interaction will last for a certain duration δt. this implies that the amplitude for the total energy involved in the interaction is spread over a range of energies δe. " - this " borrowing " idea has led to proposals for using the zero - point energy of vacuum as an infinite reservoir and a variety of " camps " about this interpretation. see, for example, moray b. king ( 2001 ). quest for zero point energy : engineering principles for ' free energy ' inventions. adventures unlimited press. pp. 124 ff. isbn 0 - 932813 - 94 - 1. - quantities satisfying a


example, moray b. king ( 2001 ). quest for zero point energy : engineering principles for ' free energy ' inventions. adventures unlimited press. pp. 124 ff. isbn 0 - 932813 - 94 - 1. - quantities satisfying a canonical commutation rule are said to be noncompatible observables, by which is meant that they can both be measured simultaneously only with limited precision. see kiyosi ito ( 1993 ). " § 351 ( xx. 23 ) c : canonical commutation relations ". encyclopedic dictionary of mathematics ( 2nd ed ed. ). mit press. p. 1303. isbn 0 - 262 - 59020 - 4. - paul busch, marian grabowski, pekka j. lahti ( 1995 ). " § iii. 4 : energy and time ". operational quantum physics. springer. pp. 77 ff. isbn 3 - 540 - 59358 - 6. - for a review, see paul busch ( 2008 ). " chapter 3 : the time – energy uncertainty relation ". in j. g. muga, r. sala mayato and i. l. egusquiza, editors. time in quantum mechanics ( 2nd ed ed. ). springer. pp. 73 ff. isbn 3 - 540 - 73472 - 4. - fowler, r., guggenheim, e. a. ( 1965 ). statistical thermodynamics. a version of statistical mechanics for students of physics and chemistry, reprinted with corrections, cambridge university press, london, page 224. - partington, j. r. ( 1949 ). an advanced treatise on physical chemistry, volume 1, fundamental principles. the properties of gases, longmans, green and co., london, page 220. - wilks, j. ( 1971 ). the third law of thermodynamics, chapter 6 in thermodynamics, volume 1, ed. w. jost, of h. eyring, d. henderson, w. jost, physical chemistry. an advanced treatise, academic press, new york, page 477. - bailyn, m. ( 1994 ). a survey of thermodynamics, american institute of physics, new york, isbn 0 – 88318 – 797 – 3, page 342. - jauch, j. m., rohrlich, f. ( 1955 / 1980 ). the theory of photons and electrons. the relat


york, isbn 0 – 88318 – 797 – 3, page 342. - jauch, j. m., rohrlich, f. ( 1955 / 1980 ). the theory of photons and electrons. the relativistic quantum field theory of charged particles with spin one - half, second expanded edition, springer - verlag, new york, isbn 0 – 387 – 07295 – 0, pages 287 – 288. - milonni, p. w. ( 1994 ). the quantum vacuum. an introduction to quantum electrodynamics, academic press, inc., boston, isbn 0 – 12 – 498080 – 5, page xv. - milonni, p. w. ( 1994 ). the quantum vacuum. an introduction to quantum electrodynamics, academic press, inc., boston, isbn 0 – 12 – 498080 – 5, page 239. - schwinger, j., deraad, l. l., milton, k. a. ( 1978 ). casimir effect in dielectrics, annals of physics, 115 : 1 – 23. - milonni, p. w. ( 1994 ). the quantum vacuum. an introduction to quantum electrodynamics, academic press, inc., boston, isbn 0 – 12 – 498080 – 5, page 418. - jaffe, r. l. ( 2005 ). casimir effect and the quantum vacuum, phys. rev. d 72 : 021301 ( r ), http : / / 1 – 5. cua. mit. edu / 8. 422 _ s07 / jaffe2005 _ casimir. pdf further reading - free pdf copy of the structured vacuum - thinking about nothing by johann rafelski and berndt muller ( 1985 ) isbn 3 - 87144 - 889 - 3. - m. e. peskin and d. v. schroeder, an introduction to quantum field theory. - h. genz, nothingness : the science of empty space - maybe this should discuss star trek and / or star gate : engineering the zero - point field and polarizable vacuum for interstellar flight - e. w. davis, v. l. teofilo, b. haisch, h. e. puthoff, l. j. nickisch, a. rueda and d. c. cole ( 2006 ) " review of experimental concepts for studying the quantum vacuum field "


regime in a remnant patch of bush. this vision assumes that such toolkits will be developed and readily utilised. underpinning this framework is a basic set of principles that should encourage actions to achieve sustainable native vegetation management. these include : - recognition that all vegetation management should be based on the overall goal of ecologically sustainable development which recognises environmental, economic and social values ; - recognition of the important role of native vegetation in the functioning of ecosystems in maintaining productivity capacity of agricultural lands ; - recognition that the biological diversity of vegetation should be maintained through appropriate land management practices. these include a suite of measures from environmental protection through to sustainable use and production using best practice management techniques ; - recognition that vegetation management requires the continuing partnership of government, land managers, industry and the wider community ; - recognition that where there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. in the application of the precautionary principle, public and private decisions should be guided by : - careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment ; and - an assessment of the risk - weighted consequences of various options ; - recognition that protecting existing remnant vegetation is the most efficient way of conserving biodiversity. native vegetation is usually managed within the broader natural resource management context that takes account of economic and social objectives additional to environmental objectives. however, sustainable native vegetation management does not only serve environmental objectives. outcomes from sustainable native vegetation management also contribute substantially to important economic and social objectives. the native vegetation outcomes being sought in this framework are : - a reversal in the long - term decline in the extent and quality of australia ' s native vegetation cover by : - conserving native vegetation, and substantially reducing land clearing ; - conserving australia ' s biodiversity ; and - restoring, by means of substantially increased revegetation, the environmental values and productive capacity of australia ' s degraded land and water ; - conservation and, where appropriate, restoration of native vegetation to maintain and enhance biodiversity, protect water quality and conserve soil resources, including on private land managed for agriculture, forestry and urban development ; - retention and enhancement of biodiversity and native vegetation at both regional and national levels ; and - an improvement in the condition of existing native vegetation. specific vegetation outcomes being sought, within the context of integrated natural resource management, are described below. biodiversity outcomes sought : - protection of biological diversity and maintenance of essential ecological processes and life -


written for political science 101 last term at the university of waterloo. node your homework they said... democracy is more than an election every few years, a familiar process removed from the daily grind until it comes time to tick a small box on a larger piece of paper. it is instead more about people than protocol, more magical and less mechanical. we should see it in terms of an ideal to which our institutions and practices strive towards, rather than the view that these infrastructures come about as a result of this intangible juggernaut of democracy. democracy is not a construct of man, it is instead a set of ideals and values we seek. the typical citizen of a liberal democratic society does not have much to say about democracy except when confronted by “ man on the street ” interviews or whenever your particular national holiday rolls around. this apathy is not a result of genuine malice, but more a testament to the fact that our particular implementation of the idea of democracy works so well it is almost transparent. no mobs run loose through his streets at night, no men dressed in black come to “ talk ” to him in the early hours of the morning. his roads, sewer, electricity and television hum day and night without losing a beat. in a more direct sense, his government functions properly and does not become a burden to him. the pleasant life he leads is a direct result of a democratic society functioning properly, and it is his very right as a citizen of this society to ignore it on a daily basis. this individualistic view of democracy cannot hold in all situations. it works for general day to day circumstances, however even the most right - wing of individualist thinkers holds a belief that under certain circumstances, citizens have a duty to perform certain tasks for the state. these duties may be mundane, such as paying taxes or voting, or extreme, such as defending one ’ s nation. all have a common thread, that which citizens as a member of a state have certain natural duties. democracy cannot exist without its members participating in it, this is a fundamental requirement. these natural duties may vary from time to time but the constant is that they always exist in some capacity or another. democracy is based upon many citizens performing small duties, instead of a small group of citizens controlling many responsibilities. the concept of working together is one that democracy builds itself upon. democracy is the rule of the people, not a person. it fulfills the innate human need to guide one ’ s destiny, through even such a small part as filling out a ballot


the concept of working together is one that democracy builds itself upon. democracy is the rule of the people, not a person. it fulfills the innate human need to guide one ’ s destiny, through even such a small part as filling out a ballot. the fact that democracy is based on such emotionally appealing ideas should give you some conception as to the reasons for its success. hobbes may have argued that we need someone to control us, but in the end, what we all really want is to control ourselves. the fact that democracy is able to take a selfish desire, such as the want to control the state, and turn it into a government which acts for the good of all is further evidence as to the robustness of the democratic ideal. democracy is an enduring dream, contrary to the doomed wunderkinds of communism and other governments based on theory not practice. while superior in their vision of a utopia on paper, they come against one fundamental flaw, namely people tend to run toward the jerk side of the personality scale. communism without greed would indeed be utopia but the real world runs up against tangible problems with this. you cannot remove greed from a man by political posturing no more than you can paint stripes on a horse and call it a zebra. it may pass on first inspection, but when it comes down to the most basic of things, you tend to run into a few problems. the reason democracy works in the physical realm is it engages in political judo, in that it takes men ’ s selfishness and desires, parries them into another direction unpredicted by the man, all with the full momentum of his swing still behind him. it has survived from the ancient greeks to this present day for this very reason. the initial view of democracy as we know it was conceived by the greeks, however the practical application of democracy we have today is drastically different from their view. initially it was the concept that every citizen ( citizens being of course aristocratic males ) would have a say in the management of the state. today however we have a different conception of this democratic ideal. pure practicality dictates that we cannot have the entire community attempt to come to a conclusion on issues addressed by the state. this was practical in the greek age where a manageable number would discuss the issues of the day, but this is not feasible in this day and age where our world population is measured in billions. the fundamental thing to remember however is that the ideal of democracy survives between this gulf of years and culture. this romanticism of democracy


issues of the day, but this is not feasible in this day and age where our world population is measured in billions. the fundamental thing to remember however is that the ideal of democracy survives between this gulf of years and culture. this romanticism of democracy is the root of its power. the society we live in values the ideals held by the democratic system, and as such we accept it as a ruling influence in our lives. an example of this is the prime minister being a “ public servant ”. only in the strictest most idealistic sense is he a genuine servant of the people ; however we call him such without a hint of irony as we value the democratic ideal so highly. all politicians are crooks we tell each other, yet we keep on voting. why, when we so enthusiastically hate the dictators and marcos of the world who embezzle funds? the answer lies in that we see democracy as striving toward an ideal. no man is perfect, but they ’ re working on it. this contradiction between reality and the psyche is at the heart of any power, and in western countries it is what tells us that democracy is the cure for all that ills a state. contradiction is fundamental to democracy. democracy brings us together we are told, it is the great equalizer. all men are born equal, none shall be held in higher esteem than another. one citizen shall have one vote. all say that the members of a democratic state are inherently equal. on the other hand we have canada, a liberal democratic society, in which multiculturalism is not only encouraged but has an official policy to address it. differences are encouraged, and any attempt to insinuate that we should all become equal is dismissed as right - wing xenophobia. where then is the balance? democracy gives us equality, but it also gives us the right to be different. it is the fine line between the two, a tightrope act of titanic proportions. the balance must not swing too far one way or the other, lest the acrobat be unset and come crashing down. the democratic ideal allows us to weigh multiculturalism and its variants against solidarity and never find a clear winner. it allows us to value them equally, as this is the ultimate measure of equality. equality can lead to problems however, if democracy becomes the rule of the “ most equal ”. a tyranny of the majority is completely democratic in the most literal sense of the word in that the majority chooses for it to be so, however it is unpalatable


problems however, if democracy becomes the rule of the “ most equal ”. a tyranny of the majority is completely democratic in the most literal sense of the word in that the majority chooses for it to be so, however it is unpalatable to many in our society. this is due to the fact that we see democracy in more than just the literal sense, we see it as a shining ideal. this ideal would not allow trampling of minority rights, and as discussed before, the ideal of democracy is the fine balance between differences and solidarity. as such we cannot allow this tyranny, permitted as it is in a literal interpretation of a democratic society. the democratic ideal implies compassion and empathy, more than just cold cruel statistics of fifty percent plus one. the democratic ideal hinges on this idea of not allowing technicalities and numbers to become the ruling force instead of a vision of participation by all. common occurrences such as majority governments being elected by a minority as seen as undemocratic, even though in the strictest sense they follow literal democracy. if your system is built upon the philosophy that a leader is elected indirectly through grouping voters into regions, this is particularly apparent. the recent florida fiasco in the american elections is a particularly apt example of this. counting non - participating voters and the popular vote, a leader was elected who received far less support from his citizens than a majority. while seen as undemocratic and a travesty, at the same time it is completely by the book. unfortunately, there is no book of democracy. we instead view democracy as an ideal not a construct. it is not a point by point leaflet we can airdrop over dictatorships, but instead an attitude that results from culture and history. it is a result of directing people ’ s desires toward solidarity, and at the same time respecting differences. while at time contradictory and awkward, it endures. it endures due to the fact that democracy is a dream not a document, and dreams are not easily lost.


the open tree of life : toward a global synthesis of phylogenetic knowledge 2013 reu project : in the field of systematic biology, scientists study species of all kinds to determine how one is related to another by evolutionary descent. in other words, they are trying to reconstruct the great tree of life - - the branching genealogy of all species, traced all the way back to a single common ancestor. ( the scientific term for ' tree of life ' is ' phylogeny '. ) individual scientists typically have expertise in only one or a few branches on the tree - - for instance, one might study dung beetles, while another studies venus flytraps. every year, experts like these publish thousands of scientific papers describing new phylogenetic trees for different group of organisms : clams, birds, mushrooms, and so on. however, these newly discovered trees are generally recorded simply as figures embedded in the pages of scientific journals. the open tree of life project seeks to extract all these trees from the literature and graft them together by entering them into a common database. this will enable computational analyses that will produce, for the first time, an estimate of the tree of life that includes all species ever studied. research methods and techniques : interns on this project will learn how to download data sets of dna sequences, perform phylogenetic analyses, and interpret the results. they will also have the opportunity to learn basic computer programming and linux shell computing, or advance their current knowledge of these topics. their contributions will be recorded in a public database for posterity. it is perfect fit for anyone interested in both biology and computers. curator / advisor : dr. richard ree ( curator, botany )