, the hemispheres. these hemispheres are united to one another through a system consisting of millions of nerve fibers. therefore, each hemisphere is continually informed about what is happening in the other. what happens if the connection is broken? a laboratory introduction to dna restriction analysis this workshop serves as an introduction to laboratory exercises in molecular biology. a guided inquiry in a computer - based biology lab computer technology is used by the research teams of 3 - 4 students to search for background information for the guided inquiry, organize this information into a concept map, complete an electronic template ( the tlnb : team lab notebook ), and analyze data with microsoft excel. a computer projection system is used to present their findings to the other teams. this format can be adapted to do open and guided inquiry laboratories in biology for both the major and non - major student. in addition it can phd forum for finance and economics on china 2010 the main theme of this forum is chinese financial reform and ' sustainable economic development under the global crisis '. new perspectives on what we can learn from china and what china might learn from the global financial crisis will be discussed. the future of iraq : the media and public response to the iraq commission following a series of hearings, channel 4 aired the findings of the channel 4 / foreign policy centre iraq commission in a special programme presented by jon snow on saturday 14 july 2007. the commission, the equivalent of the us iraq study group, is an independent, cross - party commission which has produced recommendations on the future of britain ' s role in iraq. the polis event will be the first public debate on the findings of the iraq commission. through incorporative panel debate, it will gau multicoloured gum piece the exhibition was selected by chantal crousel, director of chantal crousel gallery, paris ; chris ofili, turner prize winning artist ; and niru ratnam, critic and curator. it focused on the history of the east end academy, which first launched in 1932 as an alternative to the royal academy summer exhibition. “ multicoloured gum piece ” explores my ongoing investigation into site - specificity, temporality, and the role of public art. john mctaggart, and his paper “ the unreality of time ”, prov shown in alumni 2 : process and memory exhibition. ars magna lucis et umbrae 100 modern day ‘ magic lanterns ’ grouped in a series of narrative sequences and photographic tableaux are distributed unevenly throughout the cavernous space of the former church. two types of images are


. very useful for a newcomer to ir. this video of 6. 5 minute would be useful in a classroom setting or students interested in the technique. rsc. org : proton nmr this video, distributed on youtube by the royal society of chemistry is on the basic principles of nmr. this video is a good primer and would be very useful to supplement introductory lectures on nmr. the video covers the basic theory behind a 1h spectrum and goes through actually acquiring a spectrum. the top - off look of the instrument is useful and how the superconducting magnet is mounted. good for a basic introduction. rsc. org : mass spectrometry this video, distributed on youtube by the royal society of chemistry is on the basic principles of mass spectrometry, using a magnetic sector instrument to demonstrate how specific m / z ratios can be selected. the theory and operation of ms, including the chemistry of ionization and fragmentation is described at an introductory level. there \ ' s also an excellent example of the use of high resolution ms to differentiate between nominal mass and actual mass. the video does a very good job of explain veeco ' s nanotheater provides over 350 images of surfaces acquired using atomic force microscopy and scanning probe microscopy. images come from a wide variety of samples, including polymers, biologicals such as bacteria, and inorganic crystals. many of the images contains brief descriptions of what is being shown, although the information is not particularly in - depth. additional information on atomic force microscopy and scanning probe microcopy, including useful guides and animations, is availa this pair of ph calculation programs serves as an excellent tool for anyone wishing to calculate the ph of a solution containing multiple acids and bases. these programs allow practitioners to predict the ph of simple and complex acid / base solutions and buffers. users are encouraged to carefully read the guides provided by the author. animations and simulations in the teaching of analytical sciences this article by cynthia larive, published in the \ " abcs of teaching analytical science \ " series of the journal analytical and bioanalytical chemistry, will be of interest to faculty members teaching courses in the analytical sciences. the article provides a good introduction to the animations, simulations, and other on - line resources available on the internet. more important, it encourages instructors to develop a teaching philosophy that emphasizes the use of these materials. a primer on scanning tunneling microscopy ( stm ) a video primer on stm by prof. r. reifenberger, purdue


internet. more important, it encourages instructors to develop a teaching philosophy that emphasizes the use of these materials. a primer on scanning tunneling microscopy ( stm ) a video primer on stm by prof. r. reifenberger, purdue university nanotech center. a thorough discussion of fundamentals followed by the technical barriers and implementations - excellent graphics illustrating principles and experimental results. historical context is provided making presentation interesting. should be viewed by anyone interested in surface analysis at atomic dimensions. population genetics and statistics this website is part of the president \ ' s dna initiative and is devoted to past and current methods of macromolecules such as dna. this website introduces the student to the subject of population genetics and stresses factors that can alter allele frequencies in a population and calculations associated with the hardy - weinberg principle. the student will learn to use acceptable statistical approaches to evaluating dna data and how dna databases are constructed and applied. this site is designed as gas chromatography video this is a high quality video module demonstrating the basics of gas chromatography. highlights include different gc instruments, detectors etc., as well as unique topics such as trouble shooting and interfacing the column that are not addressed in standard texts. this resource can be run ( shockwave flash ) from the home server or downloaded to your computer. nmr of paramagnetic proteins this site presents an overview of techniques used for structural elucidation of paramagnetic metalloproteins. the content is directed to the more advanced nmr user and would be suitable for an upper division or graduate level nmr class. this website provides resources that can aid in the interpretation of nmr proton shifts, identification of ir features and mass loss identification in mass spectrometry. the original site is in german, but most ( but not all ) the content is translated on the english version of the site. from the left hand menu under spektroskopei - tools choose wizards. from here you can enter a chemical shift in ppm and the nmr tool will identify likely protons and environments that could cause the shift. enter a laboratory orientation and testing of body fluids and tissues for forensic analysts this web site is part of the president \ ' s dna initiative and is devoted to an overview of historical and contemporary techniques to characterize body tissues. the first part of the course covers basic laboratory procedures, safety requirements for laboratory personnel and emphasizes quality control and quality assurance in the laboratory. the second section deals with serological techniques for


2008. 02. 20 > for immediate release contact : wendy townley - university relations phone : 402. 554. 2762 - email : email @ example. com new cell behaviors discovered by uno research team omaha - the mathematical biology research group at the university of nebraska at omaha ( uno ) has found new evidence that individual cells have chemical circuits that allow them to process information from their environment. the finding, published in the feb. 12 issue of proceedings of the national academy of sciences of the united states of america, shows that the information processing capacity results in decision - making ability at the cellular level - - a molecular “ brain ” for cells. the results were obtained from the mathematical analysis of a new, large - scale model of the chemical pathways. the model, created by the research group, is unique in that it is based completely on the logic of the chemical interactions that make up the system. much like humans encounter a flood of sensory information from their environment that must be processed to allow rational decisions to be made, cells receive large amounts of information from their environments in the form of chemical cues. these cues are detected by cells though specific chemical receptors on their surfaces, and the numerous types of receptors form the equivalent of a cellular sensory system. it has recently been speculated that the astonishingly complex chemical networks inside the cell that are associated with these cell surface receptors might be involved in some sort of information processing, but until now the only evidence came from mostly descriptive studies of the complex structure of these networks. the uno group moved beyond description of the structure and was able to determine the complete logic of the system. in order to assess how the logic of the interactions resulted cellular action, a novel cellular simulation computer program was developed by the group that puts the cellular logic into motion. as a result, the group was able to observe and analyze how the chemical networks reacted to tens of thousands of possible cellular environments. the mathematical analysis of the results revealed that cells are able to classify different environments based on their similarities and make rational decisions as to cellular actions required in those environments. full understanding of the complex chemical networks in cells is critical as a number of human diseases, most notably cancer, result from malfunctions in the activities of individual chemicals that make up the networks. the mathematical biology research group at uno is a highly collaborative group of mathematicians and cell biologists. the members of the group that made the new discovery include john konvalina and jack heidel, both mathematicians, and jim rogers a cell biologist. the computer software was developed by tomas


simply not the case. in fact, if the strictly material conceptualization of consciousness is true, then this has profound implications for the nature and significance of human existence. isaac asimov identifies the most important of these implications : | in the last decade, scientific published several influential articles on the study of consciousness – a first for this prestigious magazine ; including one by david the puzzle of conscious experience. ( dec., 1995 ) he consciousness as being paradoxically, “ the most familiar thing in world and the most mysterious, ” and he notes the “ tangle of and conflicting theories ” existing within the field. to chalmers, the “ easy problems of consciousness ” concern the mechanisms of various forms of cognition, while the “ hard problems ” concern “ how the physical processes in the brain give rise to the basic fact of the subjective side of consciousness simply cannot be deduced from physical facts about the brain ’ s functioning. he notes we have no idea how the subjective experiences arise from neurological processes. between the physiological processes and the subjective experience, there is, in scientific terms, an explanatory gap. chalmers ’ solution is to suggest that consciousness is perhaps a “ fundamental feature of the world, ” irreducible to anything else. he compares this to basic physical concepts such as space - time, mass, charge and so on, which are regarded as fundamental properties, unexplained in terms of lower order phenomena. chalmers notes that physicist, john wheeler, suggests that “ information ” is fundamental to the physics of the universe, and that consciousness might be the “ subjective side ” of information. in this case, information would have a two fold nature as both physical and experiential, objective and subjective. thus, a model of consciousness would require a set of fundamental laws unique to the description of consciousness, analogous to the laws of physics used to describe the physical world. this is a new form of dualism – not of mind and matter – but of the subjective and objective sides of information. it also brings us back to the possibility of a substantive consciousness, which is something, whatever that might be. the problem of consciousness has given rise to a diversity of ideas and theories, and yet remains the most paradoxical, unexplained mystery within science today. generally, theorists talk over consciousness, around it, under it, about it, but have few substantive ideas which do more than scratch the surface of this profound mystery. in this critical area, science is almost purely speculative. however, almost all of the recent theoretical perspectives subscribe to


, around it, under it, about it, but have few substantive ideas which do more than scratch the surface of this profound mystery. in this critical area, science is almost purely speculative. however, almost all of the recent theoretical perspectives subscribe to the common assumption that the brain produces consciousness and the mind – although the details of this magical transformation are lacking. when we look more closely at scientific explanations of what consciousness is, and how and where it is produced by the brain, they are based on nothing more than speculation and hunches – a house of cards, as crick admits. if there is an immaterial mind, spirit and soul, and some form of irreducible consciousness, what are these things, and how do they relate to the physically body and brain? there are many issues to be resolved and all the doors should be kept open in trying to understand these mysteries. the idea that a human being has a spirit or soul, or a divine spark, has not yet been dis - proven, because the nature and origin of human consciousness pose such profound mysteries. scientists only assume that it is produced by the neurology of brain processes, as they gloss over the gaps in science. most of the science writers explaining physics and creation processes do not explore consciousness, except in a cursory way. for the most part, it is simply assumed that the brain produces consciousness, which arises at a certain level of biological complexity of brain functioning. physicists don ’ t generally consider that human beings could be ‘ conscious ’ of their own favorite vacuum states, voids or plenums, hyperspace or inner singularities, or be subject to non - local effects. the models of physics are not considered in relation to consciousness studies, and so consciousness is generally left out of the equations. psychologists don ’ t study physics, nor physicists, consciousness, and neither are conversant with mystical teachings on their own favorite subjects. scientists imagine that they discovered the quantum vacuum! and singularities! | to begin, the term be taken generally to refer to the inner awareness of being, which each of us has or is within our lives. although we might see another physical being, we cannot examine their inner world of consciousness or their experience of being. yet, in a very real sense, it is this inner world that each of us has our existence, and in order to the issues of consciousness, we must make an effort to understand it ourselves – through direct inner awareness and experience. this is necessary to supplement other scientific approaches,


this year marks that 50th anniversary of the branch of mathematics known as chaos theory. appropriately enough for a field of study premised on the idea that seemingly insignificant events can have large and unpredictable consequences, the eureka moment of chaos is generally considered to be a short dense paper titled " deterministic nonperiodic flow " published on page 130 of volume 20 of the journal of the atmospheric sciences in 1963. as james gleick writes in his very entertaining history, chaos : making of a new science, " in the thousands of articles that made up the technical literature of chaos, few were cited more often than " deterministic nonperiodic flow. " for years, no single object would inspire more illustrations, even motion pictures, than the mysterious curve depicted at the end, the double spiral that became known as the lorenz attractor. " the paper ' s author, edward lorenz, was an mit mathematician working on an early computer weather modeling simulation. one day in 1961, in an effort to save time waiting for his vacuum tube - powered royal mcbee computer to run the program, lorenz started his simulation from the middle, manually entering in data from an earlier simulation, but crucially, rounding a six decimal point number to three decimal points in order to save space. what lorenz found after returning from a coffee break was that these tiny, seemingly arbitrary changes in his initial inputs had led to vastly different outcomes in the weather models he created. as gleick writes, " lorenz saw more than randomness embedded in his weather model. he saw a fine geometrical structure, order masquerading as randomness. " lorenz, who died in 2008, would later become best known for coining the metaphor of the " butterfly effect " to describe systems that are extremely sensitive to their initial conditions. most casual readers can ' t understand much of the mathematics of chaos theory, but the basic principles were popularized thanks in part to gleick ' s bestselling book, not to mention the trippy mandelbrot set images that have graced countless screensavers and dorm room posters and, of course, jeff goldblum ' s character in jurassic park. chaos doesn ' t have quite the pop culture cachet that it used to, but the study of what lorenz called nonlinear systems - those in which outputs are not necessarily proportional to inputs - - has been highly influential in fields ranging from physics, to engineering, to astronomy, agriculture to economics. ( one of the main themes of gleick


of what lorenz called nonlinear systems - those in which outputs are not necessarily proportional to inputs - - has been highly influential in fields ranging from physics, to engineering, to astronomy, agriculture to economics. ( one of the main themes of gleick ' s books is that researchers in different fields were often working along very similar lines without being aware of each other. some of this work was actually going on years before lorenz ' s " discovery. " ) the late mathematician benoit mandelbrot ' s ideas about turbulence in financial markets have enjoyed something of a renaissance in recent years thanks the global financial crisis. i was lucky enough to get the chance to interview mandelbrot for fp a year before his death. but chaos has also had applications in some less obvious areas, such as politics and international relations. in fact, there ' s an argument to be made that the ideas behind chaos are far more intuitive in the study of politics and armed conflict than in the natural sciences where it originated. take, for example, the old english proverb that ' s second only to the butterfly effect as a commonly used layman ' s explanation for chaos : for want of a nail the shoe was lost. for want of a shoe the horse was lost. for want of a horse the rider was lost. for want of a rider the message was lost. for want of a message the battle was lost. for want of a battle the kingdom was lost. and all for the want of a horseshoe nail. what, after all, is a better example of chaos theory than the harassment of a street vendor in tunisia leading to a civil war in syria? as ohio state political scientist alan beyerchen has argued, carl von clausewitz seemed to have an intuitive grasp of the idea of nonlinear systems and chaos more than a century before anyone used those terms. take, for example, this passage from on war : [ i ] n war, as in life generally, all parts of the whole are interconnected and thus the effects produced, however small their cause, must influence all subsequent military operations and modify their final outcome to some degree, however slight. in the same way, every means must influence even the ultimate purpose. in more recent times, ideas from chaos and its related subfield complexity theory influenced the writing of columbia international relations theorist robert jervis, who in his book system argues that many social scientists don ' t adequately grapple with the fact that interconnected actors in a complex system can produce results that seem like vastly more or vastly less than


in pgp, mr zimmermann solved this by using public - key cryptography, which uses a pair of private and public keys to handle encryption. the public key is freely published and distributed online, and verified by other trusted parties. a pgp - protected document would contain an encryption key unique to the document that scrambled the file ’ s contents. that document key is itself enciphered using recipient ’ s public key. only an intended party with the corresponding private key could extract the document ’ s secret and decrypt it. that may be straightforward for expert cryptographers, but not for the vast majority of internet users. so zrtp takes a different tack. it relies on the fact that it is difficult to impersonate a voice. after a voice call is initiated with silent circle ’ s voip software, the two users are both presented with the same short number. at any point in the call, they can read this number to the other person to ensure it matches. if it doesn ’ t, an eavesdropper might be listening in. mr zimmermann notes that by “ dragging a couple of human brains into the protocol ”, silent circle makes it impossible for an interloper to predict when the people in a conversation will perform the verification step or how they will perform it, and so pre - arrange a convincing impersonation. ( video chats in silent circle will show a blank screen until the short code is verified, and the text messaging app shows the code and suggests making a brief phone call to verify it. ) „


intel preparing lasers and light to shuffle data between computers intel is readying silicon photonics for use at the motherboard level by agam shah | published : 12 : 03, 17 january 2013 intel is taking the first steps to implement thin fibre optics that will use lasers and light as a faster way to move data inside computers, replacing the older and slower electrical wiring technology found in most computers today. intel ' s silicon photonics technology will be implemented at the motherboard and rack levels and use light to move data between storage, networking and computing resources. light is considered a much faster vehicle to move data than copper cables. the silicon photonics technology will be part of a new generation of servers that will need faster networking, storage and processing subsystems, said justin rattner, intel ' s chief technology officer, at the open compute summit in santa clara, california. related articles on techworld at the conference, intel and server maker quanta computer are showing a prototype server rack architecture that is capable of moving data using optical modules. the server uses an intel silicon switch and supports the chip maker ' s xeon and atom server chips. the new rack architecture with silicon photonics is a result of more than a decade of research in intel ' s laboratories, rattner said. he said silicon photonics could enable communication at speeds of 100g bps ( bits per second ), and transfer data at high speeds while using lesser power compared to copper cables. the technology could also consolidate power supplies and fans in a data center, reducing component costs. intel ' s research revolved around the production of devices needed to implement silicon photonics at the rack level, including modulators and detectors. the company is now producing silicon photonics modules that can transfer data at 100g bps, and is offering it to a few clients for testing. silicon photonics could potentially redefine server designs, rattner said. with the high - speed bandwidth, processing and storage units could be decoupled from servers and stored in separate boxes. once the infrastructure with silicon photonics is in place, server designs could change even more, rattner said. intel is working with facebook to define new server technologies that will lead to the decoupling of computing, networking and storage resources. the high - bandwidth connection offered by silicon photonics will be key in bringing the rack technologies to reality, and the processor, switch and other modules need to work together on power management, protocol support, load balancing and handshakes to make high - speed data transfers possible. critical to


unl physicist discusses high - order harmonic generation at aaas released on 02 / 18 / 2013, at 2 : 00 am office of university communications university of nebraska – lincoln one - billionth of a billionth of a second. that ' s the scale - - an attosecond - - at which scientists seek to image and control electronic motion in matter. the principle of attosecond science was the focus of a feb. 17 symposium during the annual meeting of the american association for the advancement of science. university of nebraska - lincoln physicist anthony starace was among the speakers, presenting " high - order harmonic generation, attosecond science and control of electron motion. " starace, a george holmes university professor of physics at unl, reviewed current theoretical understanding of the " new frontier " of high - order harmonic generation and discussed the prospects for achieving the goals of attosecond science. " because electrons move on a scale of angstroms ( one 10 - billionth of a meter ), light pulses used to illuminate this motion must have high energies so that their de broglie wavelength is sufficiently small to be able to resolve, or image, the electron motion, " starace said. " also, because electrons move so fast, light pulses must have durations that are shorter than the typical time scale for electron motion. " de broglie waves, a theory of quantum mechanics, indicate how a wavelength is inversely proportional to the momentum of a particle. attosecond pulses are becoming the preferred tools for imaging, visualizing and even controlling electrons in matter in their natural time scale. attosecond research could eventually open new applications in a wide range of fields, including nanotechnology and life sciences, based on the ultimate visualization and control of the quantum nature of the electron. attosecond science evolved from advances in modern laser technology that allow generation of ultra - short light pulses, or high - order harmonic generation - - starace ' s area of expertise. starace joined seven other scientists to discuss " attosecond science in chemical, molecular imaging, spintronics and energy science. " the aaas annual meeting was feb. 14 - 18 in boston. at this convention, thousands of leading scientists, engineers, educators and policymakers interact in more than 150 sessions and seminars. starace is fellow of the american physical society and aaas. he earned his bachelor ' s degree at columbia college, his master ' s and doctorate at the university of chicago, and did


laser physicists are good at producing and manipulating single photons, but as with good comedy, the timing is important. even the best experiments in quantum cryptography and computing – applications that make use of single photon properties – use sources that emit photons at random times. in the 4 october prl a french team demonstrates a system that emits single photons on a dependable schedule at a frequency of 3 mhz. one other “ triggered ” photon source which operates on completely different principles was reported earlier this year. with these new techniques, researchers know exactly when and where a single photon will be found, and they are a step closer to quantum applications, such as cryptography that allows the receiver of information to deduce whether a message has been intercepted. imagine a photon counter in front of a very weak laser beam. the number of photons reaching the detector in a given period of time ( the laser power ) may be precisely known, but the photons will arrive at random times. even a pulsed laser can ’ t be rigged to produce single photons on a schedule. to generate photons at specific times, michel orrit of the french national center for scientific research ( cnrs ) in talence and his colleagues used the fact that a dye molecule will dependably emit a single photon within a matter of nanoseconds every time it ’ s raised to the right energy level, and they excited such a molecule in a controlled and repeatable way. from previous work, the team had learned that with a dilute solution of a dye chilled to 4 k they could target a single molecule using a well - focused laser beam. for their latest experiments, orrit and his colleagues simultaneously applied a variable electric field across the frozen sample, which allowed them to slightly alter the frequency of light needed to excite the dye molecules. with the sample continuously illuminated by an excitation laser, the team applied an oscillating electric field at a frequency of 3 mhz, so that the dye molecule was excited twice per cycle – at the moments in time when the laser frequency matched the molecule ’ s resonant frequency. ideally, this clock - like process would cause the molecule to flash a fluorescence photon with each excitation, but the system was not perfectly efficient. to collect the photons, the tiny sample was surrounded by a small, dish - shaped ( paraboloid ) reflector. the team could not dependably detect every photon, so they verified the timing by measuring eight minutes worth of the signal and showing that


first international conference on information and communication technologies : from theory to applications – ictta ’ 04. april 19 - 23, 2004, omayyad palace, damascus, syria : library and information professionals and knowledge management applications : prepared by : nagat william girgis | | 2. knowledge hierarchy a further dimension considers the premise that knowledge can be organized into a hierarchy. several authors draw distinctions between data, information, and knowledge : 2. 1. data : facts, images, or sounds ( + interpretation + meaning = ) 2. 2. information : formatted, filtered, and summarized data ( + action + application = ) 2. 3. knowledge : instinct, ideas, rules, and procedures that guide actions and decisions. knowledge has two basic definitions of interest. the first pertains to a defined body of information. depending on the definition, the body of information might consist of facts, opinions, ideas, theories, principles, and models ( or other frameworks ). clearly, other categories are possible, too. subject matter ( e. g., chemistry, mathematics, etc ) is just one possibility. knowledge is commonly distinguished from data and information. data represent observations or facts out of context, and therefore not directly meaningful. information results from placing data within some meaningful context, often in the form of a message. knowledge is that which we come to believe and value based on the meaningfully organized accumulation of information ( messages ) through experience, communication or inference. knowledge can be viewed both as a thing to be stored and manipulated and as a process of simultaneously knowing and acting - that is, applying expertise. as a practical matter, organizations need to manage knowledge both as object and process. knowledge can be tacit or explicit. tacit knowledge is subconsciously understood and applied, difficult to articulate, developed from direct experience and action, and usually shared through highly interactive conversation, story - telling and shared experience. explicit knowledge, in contrast, can be more precisely and formally articulated. therefore, although more abstract, it can be more easily codified, documented, transferred or shared. explicit knowledge is playing an increasingly large role in organizations, and it is considered by some to be the most important factor of production in the knowledge economy. imagine an organization without procedure manuals, product literature, or computer software.


this page is a translated version of a page kalzium and the translation is 100 % complete. home » applications » education » en | | kalzium is an information system about periodic system of the chemical elements. | it is part of the kde education project. kalzium is an application which will show you some information about the periodic system of the elements. therefore you could use it as an information database. kalzium has already some nice features but there are still a lot of things to do. as kalzium has been included in kde 3. 1 we are currently coding quite lot to bring in some new and nice features and make it as fast and useful as possible. you can help us by testing it or make proposals for new features or a better design. - versatile overview of all important data from the elements like melting points, electron affinity, electronegativity, electron configuration, radii, mass, ionization energy - tool to visualize the spectral lines of each elements - different colored views to the pse : separation of the different blocks, year simulator, temperature simulator - molecular weight calculator, concentration calculator, nuclear calculator, gas calculator, titration calculator - an isotope table - 3d molecule editor, with a load and save functionality - an equation solver for stoichiometric problems - file type conversion for different types of chemical programs - tool to produce a comprehensive list of all risk and safety statements | | the main window of kalzium shows you the periodic table. you can choose between different color schemes. look at more screenshots... there are several chemistry - applications out there. a list of the ones we find especially useful can be found on the other chemistry - applications page. kalzium has its own mailinglist : this page was last modified on 20 july 2011, at 16 : 44. this page has been accessed 1, 694 times. content is available under creative commons license sa 3. 0 and the gnu free documentation license 1. 2.


present by : george nikolopoulos, regional sales manager cellulose is the most abundant natural organic material on earth. most plants, especially trees, produce it as a structural material with long chains of simple glucose sugar molecules derived from photosynthesis. cellulose, the principle component of wood, has many applications. in foods, it is indigestible and hard to chew. with chemical modification, cellulose derivatives become very useful in foods, pharmaceuticals and many other familiar products. these derivatives are differentiated by the substitutions of various molecules along the polymer backbone. perhaps the most useful and versatile derivatives are the methylcelluloses ( mc ) : - cmc - sodiumcarboxymethylcellulose - hmc - hydroxymethylcellulose - hemc - hydroxyethylmethylcellulose - hpmc - hydroxypropylmethylcellulose and the hydroxyalkyl derivatives : - hec - hydroxyethylcellulose - hpc - hydroxypropylcellulose cellulose gums are favored for their properties of viscosity building, film forming, emulsion stabilization, binding and freeze - thaw stabilizing. one unique property is gel formation at elevated temperatures. in contrast to most gels, mcs can form reversible gels at cooking temperatures that liquify as the product cools. food processors use cmc to thicken gravies, gums and sauces ; stabilize oil / water emulsions or stabilize gas bubbles in whipped toppings with its film forming and surfactant properties ; as a non - caloric bulking agent and binder in prepared foods ; and to prevent ice crystal growth in frozen foods. cmc is the active ingredient in fiber laxatives. pharmaceutical companies use mcs as binders, time release agents and inert fillers in tablets ; as film coatings in capsules ; and thickeners in syrups. one challenge with cellulose gums is rapid dispersal in aqueous systems. the powder hydrates to form lumps that swell and stick to processing equipment or to form smaller clumps in water, commonly referred to as " fisheyes ". while these eventually disperse, various strategies have been developed to avoid waiting for hours. admix recommends using a high shear mixer like our rotosolver or rotostat dispersers. these mixers make quick, smooth solutions of gums in minutes rather


the spectrum of riemannium erbium and eigenvalium among the spectra in figure 1 is a series of 100 energy levels of an atomic nucleus, measured 30 years ago with great finesse by h. i. liou and james rainwater and their colleagues at columbia university. the nucleus in question is that of the rare - earth element erbium - 166. a glance at the spectrum reveals no obvious patterns ; nevertheless, the texture is quite different from that of a purely random distribution. in particular, the erbium spectrum has fewer closely spaced levels than a random sequence would. it ' s as if the nuclear energy levels come equipped with springs to keep them apart. this phenomenon of " level repulsion " is characteristic of all heavy nuclei. what kind of mathematical structure could account for such a spectrum? this is where those eigenvalues of random hermitian matrices enter the picture. they were proposed for this purpose in the 1950s by the physicist eugene p. wigner. as it happens, wigner was another princetonian, who could therefore make an appearance in our movie. let him be the kindly professor who explains things to a dull student, while the audience nods knowingly. the dialogue might go like this : wigner : come, we ' ll make ourselves a random hermitian matrix. we start with a square array, like a chessboard, and in each little square we put a random number.... student : what kind of number? real? complex? wigner : it works with either, but real is easier. student : and what kind of random? do we take them from a uniform distribution, a gaussian...? wigner : customarily gaussian with mean 0 and variance 1, but this is not critical. what is critical is that the matrix be hermitian. a hermitian matrix — it ' s named for the french mathematician charles hermite — has a special symmetry. the main diagonal, running from the upper left to the lower right, acts as a kind of mirror, so that all the elements in the upper triangle are reflected in the lower triangle. student : then the matrix isn ' t really random, is it? wigner : if you insist, we ' ll call it half - random. we fill the upper half with random numbers, and then we copy them into the lower half. so now we have our random hermitian matrix m, and when we calculate its eigenvalues.... student : but how do i do


we fill the upper half with random numbers, and then we copy them into the lower half. so now we have our random hermitian matrix m, and when we calculate its eigenvalues.... student : but how do i do that : you start up matlab and you type " eig ( m ) "! eigenvalues go by many names, all of them equally opaque : characteristic values, latent roots, the spectrum of a matrix. definitions, too, are more numerous than helpful. for present purposes it seems best to say that every n - by - n matrix is associated with an nth - degree polynomial equation, and the eigenvalues are the roots of this equation. there are n of them. in general, the eigenvalues can be complex numbers, even when the elements of the matrix are real, but the symmetry of a hermitian matrix ensures that all the eigenvalues will be real. hence they can be sorted from smallest to largest and arranged along a line, like energy levels. in this configuration they look a lot like the spectrum of a heavy nucleus. of course the eigenvalues do not match any particular nuclear spectrum level - for - level, but statistically the resemblance is strong. when i first heard of the random - matrix conjecture in nuclear physics, what surprised me most was not that it might be true but that anyone would ever have stumbled on it. but wigner ' s idea was not just a wild guess. in werner heisenberg ' s formulation of quantum mechanics, the internal state of an atom or a nucleus is represented by a hermitian matrix whose eigenvalues are the energy levels of the spectrum. if we knew the entries in all the columns and rows of this matrix, we could calculate the spectrum exactly. of course we don ' t have that knowledge, but wigner ' s conjecture suggests that the statistics of the spectrum are not terribly sensitive to the specific matrix elements. thus if we just choose a typical matrix — a large one with elements selected according to a certain statistical rule — the predictions should be approximately correct. the predictions of the model were later worked out more precisely by dyson and others. » post comment


novel technology for renewable resource utilization location : renewable product technology research unit title : soybean oil and methyl oleate adsorption onto a steel surface investigated using a quartz crystal microbalance with dissipation monitoring and atomic force microscopy * * 1 submitted to : meeting abstract publication type : abstract only publication acceptance date : may 10, 2012 publication date : may 10, 2012 citation : evans, k. o., biresaw, g. 2012. soybean oil and methyl oleate adsorption onto a steel surface investigated using a quartz crystal microbalance with dissipation monitoring and atomic force microscopy * * 1 [ abstract ]. society of tribologists and lubrication engineers. paper # 1245562. the united states ’ 2010 annual production of soybean oil exceeded 8 million metric tons, making a significant vegetable oil surplus available for new uses, particularly as a lubricant. investigation of soybean oil and methyl oleate adsorption onto steel using a quartz crystal microbalance with dissipation monitoring revealed that both adsorbed as rigid films with nearly the same surface concentration. further analysis revealed that the films formed with individual molecules tilted toward the surface. atomic force microscopy also revealed that methyl oleate adsorbed with periodicity of alignment on highly ordered pyrolytic graphite. more and more recent research has been focused on renewable sources such as vegetable oils as lubricants. this interest is a result of the global environmental concerns about the continued use of petroleum products. vegetable oils are abundant, biodegradable, and environmentally friendly. typically liquid at room temperature, vegetable oils have low volatility and a narrow temperature range for viscosity changes. therefore, vegetable oils can be treated as functional fluids and thus can be studied as lubricant base oils or additives. the amphiphilic properties of triacylglycerides ( tags ), the major component of most vegetable oils, affect the boundary lubrication of vegetable oils. however, understanding the fluid and boundary characteristics of vegetable oils is required to fully understand their tribological properties. boundary characteristics of vegetable oils can be better understood by exploring adsorption properties of the oils. adsorption, occurring mainly through polar groups of vegetable oil, can be monitored using the quartz crystal microbalance with dissipation ( qcmd ) technique. qcmd measures changes in thin film deposition on an oscillating surface by simultaneously monitoring frequency shifts ( delta f ) in the resona


oil, can be monitored using the quartz crystal microbalance with dissipation ( qcmd ) technique. qcmd measures changes in thin film deposition on an oscillating surface by simultaneously monitoring frequency shifts ( delta f ) in the resonating surface and changes in the dissipation of the oscillations ( delta d ). structural properties may be monitored using atomic force microscopy ( afm ). previously it was shown that the chemical properties of a vegetable oil affected its free energy of adsorption ( delta gads ) on steel. these studies, however, did not provide any information about the adsorption behavior of these oils onto the steel surface. thus, the objective of this work is to use qcmd and afm to investigate structural and absorption behavior of two previously studied oils, soybean oil and methyl oleate, onto steel. results and discussion soybean oil over the concentration range of 1 to 200 mm was monitored for adsorption onto stainless steel using qcmd. as figure 1 depict, soybean oil exhibited rapid adsorption in hexadecane. the frequency shifts ( delta f ) exhibited a large decrease with the introduction of increasing concentration of soybean oil, followed by an increase in frequency with a subsequent rinse with hexadecane. dissipation shifts exhibited rapid increases with increasing soybean concentrations followed by reduction after rinsing. these frequency and dissipation changes are indicative of increasing bulk viscoelastic properties of the material. after the subsequent rinsing with hexadecane, soybean oil was permanently bound to the steel ( as depicted by frequency shifts lower than the pre - injection values ). dissipation values remained well within those taken for adsorbing thin, rigid films ( delta d = 1e - 6 ). methyl oleate exhibited similar behavior. rodahl and kasemo ( 1996 ) detailed thin film adsorption to have a linear relationship with frequency shifts assuming that the adsorbed mass is small compared to the crystal, the adsorbed mass is rigidly bound and not slipping, and is distributed evenly over the surface. for soybean oil and methyl oleate above 100 mm, the delta f values after hexadecane rinsing remained constant. this was interpreted as full surface coverage by soybean oil and methyl oleate equal to a maximum adsorbed mass of 130 and 50 ng / cm2, respectively. further analysis suggests that soybean


in living cells, proteins are in continuous motion and interaction with the surrounding medium and / or other proteins and ligands. these interactions are mediated by protein features such as electrostatic and lipophilic potentials. the availability of protein structures enables the study of their surfaces and surface characteristics, based on atomic contribution. traditionally, these properties are calculated by physico - chemical programs and visualized as range of colors that vary according to the tool used and imposes the necessity of a legend to decrypt it. the use of color to encode both characteristics makes the simultaneous visualization almost impossible, requiring these features to be visualized in different images. in this work, we describe a novel and intuitive code for the simultaneous visualization of these properties. recent advances in 3d animation and rendering software have not yet been exploited for the representation of biomolecules in an intuitive, animated form. for our purpose we use blender, an open - source, free, cross - platform application used professionally for 3d work. on the basis blender, we developed bioblender, dedicated to biological work : elaboration of protein motion with simultaneous visualization of their chemical and physical features. electrostatic and lipophilic potentials are calculated using physico - chemical software and scripts, organized and accessed through bioblender interface. a new visual code is introduced for molecular lipophilic potential : a range of optical features going from smooth - shiny for hydrophobic regions to rough - dull for hydrophilic ones. electrostatic potential is represented as animated line particles that flow along field lines, proportional to the total charge of the protein. our system permits visualization of molecular features and, in the case of moving proteins, their continuous perception, calculated for each conformation during motion. using real world tactile / sight feelings, the nanoscale world of proteins becomes more understandable, familiar to our everyday life, making it easier to introduce " un - seen " phenomena ( concepts ) such as hydropathy or charges. moreover, this representation contributes to gain insight into molecular functions by drawing viewer ' s attention to the most active regions of the protein. the program, available for windows, linux and macos, can be downloaded freely from the dedicated website http : / / www. bioblender. eu webcite the fact that we humans are very good at extracting information through visual observation is well synthesized in the old adage " a picture is worth a thousand words ". the solution of the 3d structure of myoglo


important scientific efforts and add to their educational value the bonus of rising interest in the general public to approach biology. for our purpose we use blender, an open - source, free, cross - platform 3d application. blender is a powerful instrument for 3d modeling, animation, gaming and rendering, that provides a complete workbench for producing still images, simple animations or very complex scenes with thousand of objects in motion, all textured, lighted and filmed for proper view. traditionally, the process of creating a 3d animation film consists of a number of steps roughly grouped in modeling, animation, rendering, special effects and compositing. blender offers a platform to elaborate and integrate all of these steps. objects are created in the virtual world by modeling them in the 3d scene starting from primitives or by importing them from other programs. a time line holding key frames ( points in time in which objects have defined configuration set - ups ) is used to animate the objects in the scene in various ways : by direct rotations / translations of the object, by mesh deformation obtained moving its components ( vertices, edges, faces ), via skeleton ( inverse or forward kinematics ) or by using the game engine ( ge ), typically deployed in video games. additionally, physics - based animations can be achieved by simulated forces such as gravity, magnetic, vortex, wind etc. objects are given a surface appearance by the use of material shaders and textures. these two elements define the behavior of the surface when illuminated, by specifying local information like color, reflectance ( dull or shiny ) and microstructure ( roughness or smoothness ). once the animation and texturing is defined, the scene is equipped with other assets such as a background, lights and cameras and the process concludes with the ' filming ' ( rendering of all frames which are assembled to generate a video ). in this article, we illustrate a step forward in the direction of using bio - animation both as a divulgation and as a discovery tool. our aim is to visualize molecules in a directly informative way, also showing their motion obtained from structural data ( figure 1 ). this task is done using bioblender, in which blender is used to access several scientific programs. bioblender is an engine built in blender with an interface for biological visualization ( figure 2 ). figure 1. example of bioblender representation. the protein ( calmodulin ) is shown with its chemical and physical features represented according to the proposed


- minimum potential ) and a parameter that represents the general line density ( expressed as number of lines × ev / a2 ). by modulating this parameter users can select the most appropriate value for a group of proteins, obtaining a concentration of field lines which is coherent across the various proteins. once the ' interesting ' locations ( points ) are selected, the lines are calculated by following the gradient in both directions, iteratively moving with small steps according to the gradient ( small - step integration ). line points are added until one of the following three conditions is met : 1. the limit of the calculated grid is reached, 2. the line intersects the mesh or 3. the field is too low ( the gradient is approximately 0 or equal to the value set by the user ). the lines are saved as sequences of points in an ascii file (. txt ). thanks to the random nature of the selection procedure, lines do change every time the procedure is run but the more electrically active areas ( where more lines are present ) are readily identifiable. this property proves to be particularly effective when represented in animation, since it gives the idea of fuzziness, useful for electricity representation, while conveying the information about ep distribution on the surface. in the case of calmodulin, depicted in figure 1, and even more evident in the webgl animated representation, most lines are directed towards the surface, due to the fact that the protein is slightly acidic, with an isoelectric point of 4. 09. field lines are imported into blender as nurbs curves which are not rendered ( they are invisible in the final image ), but instead are used to guide a particle effect. every curve starts at its most positive end which is associated with a particle emitter. the particles, drawn as short segments, flow along the curves from positive to negative, respecting the field lines convention in physics. during animation, the particles are generated every 5 frames ( 0. 2 sec ) and have a life - time of 20 frames ( 0. 8 sec ). this means that the system is in steady state after the sixteenth frame ( see the scheme in figure 6 ). representation of ep as moving particles on a trajectory, played in time, is interpreted easily and transmits the idea of polarity of the charged areas of a biomolecule. figure 6. particles generation and representation for moving proteins. field lines are imported as curves every 5 frames ( 0. 2 seconds ). particles have a life - time of 20 frames ( 0. 8 seconds


charged areas of a biomolecule. figure 6. particles generation and representation for moving proteins. field lines are imported as curves every 5 frames ( 0. 2 seconds ). particles have a life - time of 20 frames ( 0. 8 seconds ). after the sixteenth frame ( 0. 6 seconds ) the system is in ready - state ( square ). if the user is interested in visualization of only one conformation, the animated particles are displayed / played in loop ( they are emitted for 250 frames and have a lifetime of 20 frames ). in the visualization of proteins in motion, every frame is elaborated as a single. pdb file. because at every frame the atomic coordinates change, also the surface features ( shape itself, ep and mlp, calculated by integrating the atomic values ) change accordingly, and must be recalculated. due to extremely high - level modifications ( topology changes, merging / separation of surface parts ) it is not possible to use a single geometry and animate it through conventional tools. it is instead necessary to rebuild the surface geometry, importing a new set of mesh coordinates at each frame. this implies a very large amount of calculations, but allows the elaboration of a sequence of images that is coherent from frame to frame, thus giving the impression of continuity. in summary, for each frame ( conformation ) we visualize mlp as textured mesh and ep as curves and animated particles. the result is a sequence of frames showing the moving protein with its properties, ep and mlp, represented together : mlp as a range of visual and tactile characteristics and ep as flow of particles that move from positive to negative along invisible field lines ( as shown in the movie protein expressions - study n. 3 ). the description of biological phenomena has always made use of graphical presentation, starting from the early botanical and zoological drawings, including famous anatomical folios, that greatly help viewers, professionals and not, to understand and learn about nature. since the early times, an artistic component has been included, often unnoticed by viewers, but greatly exploited by the scientists / artists. even today, the clearest graphical descriptions of natural and artificial subjects are hand - or cg - drawn rather than photographic images. the ' artistic ' dimension allows for a better interpretation of the subject, the choice of illumination, and the removal of irrelevant details and disturbing effects. the same attitude has motivated a number of scientists to use various graphical tricks when showing data related to structural features of macromolecules.


a better interpretation of the subject, the choice of illumination, and the removal of irrelevant details and disturbing effects. the same attitude has motivated a number of scientists to use various graphical tricks when showing data related to structural features of macromolecules. although most structural information contained in a. pdb file ( a list of atoms and their 3d coordinates ) is actually ' readable ', biologists typically use graphical programs to explore protein structures ; indeed the literature has an abundance of such programs, including some very popular. these programs can transfer the structural information from a linear list of atoms to a 3d virtual space and display it on 2d surface ; positional information is interpreted with the aid of chemical information stored in libraries ( of amino acids, nucleotides and other molecules ), that introduce chemical bonds, electric charges, hydrophobicity scales and so on. in this way the user is enabled to observe features of the molecules of interest according to her / his needs. recent years have seen the development of 3d computer graphics techniques that have culminated in the recent success of the blockbuster movie avatar, in which an entire world has been created in cg, including ' floating mountains ' and forest with thousands of ( cg built! ) plants, animals, insects etc. similar techniques can be used to show the nanoscopic world of cells, populated with all sorts of environments, proteins, nucleic acids, membranes, small molecules and complexes. indeed, there are several remarkable examples of efforts in this new discipline of bio - animation, some of which have reached a large public. beside the beauty and the educational value of these animations, we consider that the very process of creating such movies includes a heuristic importance both in the development of the graphical instruments and in the studies implied in the elaboration of the subjects ' ( proteins ) movements and interactions. in fact, when a researcher is induced to take a different point of view, such as needed for the visual elaboration, s / he will be exposed to possible new insight, facilitating better understanding of the process under study. in this way a novel spatial reasoning can complement the classical biochemical reasoning typically employed in molecular research. our group is among those involved in the development of animated biology, and in this paper we report one aspect of such effort, namely the elaboration, using blender, of a code capable of showing two of the most critical features that determine the behavior of macromolecules : their electrostatic and lipophilic potentials. choice of blender among


visual elaboration. it is important to notice that this procedure can be applied to any. pdb or ( better ) sequence of. pdb files representing a continuous series describing a conformational transition, obtained by blender or by any other means, e. g. molecular dynamics simulation. visualization of moving proteins, and of their molecular surface features the development of structural biology that made available tens of thousands of structures, not only improved our knowledge on structural features such as the richness of protein folds ( secondary and tertiary structure ), and of their association in groups ( quaternary structure ). it also increased knowledge associated with protein motion : in fact most proteins exert their function through some kind of motion. this is best understood by observing the movement in an animated film. the role of side chains, which are the determinants of such motions, is at present difficult to appreciate by using present visualization tools that either provide a fixed all - atom structure, or show dynamically only a limited number of atoms. we present here a procedure that allows the direct observation of moving proteins focusing on their surface features, rather than on their structure. in particular, we have focused on hydropathy and electrical fields as they appear on and around the molecular surface. these features can be calculated and visualized by a number of programs, which typically display them with a color code. we reasoned that for these properties a more ' photo - realistic ' display would help viewers in the de - codification of their meaning, and elaborated the system here reported. example of the use of these codes can be seen for a single protein in the proteopedia page ( see also additional file 1 ) and for a complex in our movie protein expressions - study n3. additional file 1. calmodulin in motion. the movie ( in. avi format ) shows several transitions of calmodulin in the apo form ( without calcium ) and the major conformational change induced by the binding of 4 ca ions. the movie can also be seen online at http : / / proteopedia. org / wiki / index. php / calmodulin # calmodulin _ in _ motion webcite. format : avi size : 14. 2mb download file the main idea of the proposed visual mapping is to exploit perceptual associations between the values to be mapped and visual characterization of real - world objects. ideally, by using already established perceptual association, the viewer will be able to understand the provided information more naturally,


visual mapping is to exploit perceptual associations between the values to be mapped and visual characterization of real - world objects. ideally, by using already established perceptual association, the viewer will be able to understand the provided information more naturally, without the use of explicit legends. for mlp mapping, two opposite surface characterizations able to convey a sense of affinity to water or to oil were selected. in our real - world experience, a very smooth, hard surface ( like porcelain or wax ) is completely impervious to water but can be easily coated by oil. the opposite visual feedback is associated to grainy, crumbly, dull surfaces ( like clay bricks or biscuits ) which can be easily imagined being soaked in water. these considerations led to the ' painting ' of highly hydrophobic areas as shiny, smooth material and of highly hydrophilic areas as dull and rough. while the mlp value is only observable on the surface itself, electrical phenomena are associated to the idea of an effect projected in the volume surrounding a charged object, and able to affect other objects ( like the high school favorite amber rod attracting paper bits ). field lines are a common way to describe the effect of the electrical field. ep value is therefore represented by showing small particles, moving along the path defined by field lines, visualizing a high concentration of particles in areas where the electrical field is stronger. the representation of both features in black and white allows the viewer to grasp their values, without distracting with arbitrary information which is not interpretable if not associated with a de - coding legend, making it easier to interpret. for mlp elaboration we considered that none of the available programs are accurate enough to provide useful information : most molecular displaying packages simply attribute a fixed value of mlp to every atom of a given amino acid, using the kyte - doolittle scale. this scale was elaborated almost 30 years ago with the aim of identifying structural features of proteins, namely the interior portions of globular proteins and membrane spanning segments in membrane associated proteins, but is not indicated for the evaluation of the distribution of mlp on the molecular surface. indeed, some other programs include a more appropriate method of calculation, such as vasco which employs the brickman formula on an atom based library and a fermi - type distance function. we have implemented a calculation with the testa formula, which uses an atom - based fragment scheme and an exponential function. the values thus obtained are plotted on the vertices of the molecular surface. this procedure results in a


fermi - type distance function. we have implemented a calculation with the testa formula, which uses an atom - based fragment scheme and an exponential function. the values thus obtained are plotted on the vertices of the molecular surface. this procedure results in a very smooth distribution of mlp values which is then displayed with a scale of ' tactile ' textures, ranging from dull - rough to shiny - smooth. the advantage of such calculation and representation is mostly noticeable in animated movies showing the transition between different conformation of proteins, when patches of hydrophobic areas are gradually exposed on the surface of proteins which will facilitate docking onto other macromolecules. for ep, we developed a visual code based on a flow of particles ( small lines ) flowing towards the negative pole : this is particularly useful for the observation of interacting molecules and for molecules whose field is changing when the conformation changes. to elaborate ep we made use of several programs and integrated them in a flow whose final result is the continuous display of the ep and its development during protein conformational transitions. the entire process is very fast : a protein of 2262 atoms is imported in 7 sec, while mlp and ep computation with grid spacing 1 a take 70 and 19 seconds, respectively, on a standard personal pc equipped with windowsxp, intel core 2duo cpu, 2. 33 ghz, 3. 25 gb ram. our example is calmodulin : after activation due to the binding of 4 calcium ions, the protein undergoes a major conformational transition in which both its ep and its mlp change considerably : the ca ions introduced in the 4 ef hand domains affect the ep by virtue of their own charge and the mlp by inducing the opening of each globular domain to expose two major hydrophobic patches which enable the protein to interact with its partners and push the calcium signal downstream in the biochemical pathway. in conclusion, we have developed a computational instrument that allows the display of molecular surfaces of moving ( or still ) proteins, putting special emphasis on their electrical and lipophilic properties. we consider that this representation allows better ( or at least more immediate and intuitive ) understanding of the dynamical forces governing intermolecular interactions and thus facilitate new insights and discoveries. ep : electrostatic potential ; mlp : molecular lipophilic potential ; ge : game engine ; cg : computer graphics ; 3d : three - dimensional. the authors declare that they have no competing interests. rma performed research, wrote and tested software ; mc, mfz


: molecular lipophilic potential ; ge : game engine ; cg : computer graphics ; 3d : three - dimensional. the authors declare that they have no competing interests. rma performed research, wrote and tested software ; mc, mfz, gm contributed programming ; mc, mcp contributed scivis. exe and bioblender interface, respectively ; tl, mz contributed visual elaboration with blender ; mz conceived research ; rma, mz wrote paper. we thank the pdb2pqr, apbs, pymol teams, late warren delano and the blender users and developers community for kind answers to our many questions. work funded by regione toscana grant ' animazione 3d ' to mz. this article has been published as part of bmc bioinformatics volume 13 supplement 4, 2012 : italian bioinformatics society ( bits ) : annual meeting 2011. the full contents of the supplement are available online at http : / / www. biomedcentral. com / 1471 - 2105 / 13 / s4. j mol graph 1996, 14 : 33 - 8. 27 - 8pubmed abstract | publisher full text rocchia w, sridharan s, nicholls a, alexov e, chiabrera a, honig b : rapid grid - based construction of the molecular surface and the use of induced surface charge to calculate reaction field energies : applications to the molecular systems and geometric objects. broto p, moreau g, vandycke c : molecular structures : perception, autocorrelation descriptor and sar studies. system of atomic contributions for the calculation of the n - octanol / water partition coefficients. calmodulin motion on proteopedia [ http : / / proteopedia. org / wiki / index. php / calmodulin # calmodulin _ in _ motion ] webcite callieri m, andrei r, di benedetto m, zoppe m, scopigno r : visualization methods for molecular studies on the web platform. in proceedings of the 15th international conference on web 3d technology : 22 - 24 july 2010 ; los angeles, california. edited by spencer sn. acm : new york, ny, usa ; 2010 : 117 - 126.


the optical signal power being launched into a span of transmission fiber from a transmitter module. transmitter modules typically contain a bank of distributed feedback lasers. each distributed feedback laser provides light at a different wavelength. each wavelength corresponds to a respective wavelength - division - multiplexing channel. in some systems, data may be transmitted by modulating the distributed feedback lasers directly. in other systems, data may be transmitted by using high - speed modulators to modulate the light from the distributed feedback lasers. the high - speed modulators may be part of the distributed feedback laser devices or may be external modulators such as lithium niobate waveguide modulators. an optical multiplexer may be used to combine modulated light at different wavelengths from the distributed feedback lasers for transmission on a span of optical fiber. a booster amplifier may be used to increase the signal power of the multiplexed light before it is launched onto the span. with this type of arrangement, it may be desirable to adjust the optical spectrum of the signals being transmitted before providing the signals to the booster amplifier. it is therefore an object of the present invention to provide ways in which to modify the power spectrum of the channels being transmitted to a span of optical fiber in a wavelength - division - multiplexing communications link. it is another object of the present invention to provide a booster amplifier with spectrum conditioning capabilities. summary of the invention these and other objects of the invention are accomplished in accordance with the present invention by providing optical amplifier equipment for use in a fiber - optic communications link in which optical signals are transmitted on a series of spans of optical transmission fiber. optical data signals on channels of different wavelengths may be produced by a transmitter module. a booster amplifier may be used to amplify the optical data signals. the booster amplifier may include a multiplexer that combines the signals at the different wavelengths from the transmitter module onto a single optical fiber. optical gain stages in the booster amplifier may be used to amplify the optical signals on this fiber. the booster amplifier may include variable optical attenuators or other signal conditioning components that modify the optical spectrum of the optical data signals before the signals are transmitting over the optical communications link. further features of the invention and its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. brief description of the drawings fig. 1 is a schematic diagram of an illustrative fiber - optic communications link with booster and in - line optical amplifiers in accordance with the present invention. fig.


description of the preferred embodiments. brief description of the drawings fig. 1 is a schematic diagram of an illustrative fiber - optic communications link with booster and in - line optical amplifiers in accordance with the present invention. fig. 2 is a schematic diagram of a portion of a fiber - optic communications link showing the operation of a service channel in accordance with the present invention. fig. 3 is a schematic diagram of an illustrative network node at which a booster amplifier may be used to amplify optical signals from a transmitter in accordance with the present invention. fig. 4 is a schematic diagram of an illustrative transmitter and an illustrative booster amplifier in accordance with the present invention. fig. 5 is a schematic diagram of an illustrative booster amplifier in accordance with the present invention. fig. 6 is a schematic diagram of another illustrative booster amplifier in accordance with the present invention. figs. 7a, 7b, 7c, and 7d are graphs showing how a booster amplifier of the present invention may be controlled to produce a desired output spectrum in accordance with the present invention. fig. 8 is a flow chart of illustrative steps involved in controlling a booster amplifier in accordance with the present invention. fig. 9 is a schematic diagram of a portion of a booster amplifier showing how optical taps and monitoring circuitry may be used to monitor optical signals in the amplifier to control transients in accordance with the present invention. fig. 10 is a schematic diagram of a portion of an illustrative booster amplifier showing how the gain stages of the amplifier may include coils of optically - pumped fiber in accordance with the present invention. fig. 11 is a flow chart of illustrative steps in controlling the gain stages of a booster amplifier during operation to prevent gain transients in accordance with the present invention. fig. 12 is a schematic diagram showing illustrative system locations in which booster amplifiers may be used in accordance with the present invention. detailed description of the preferred embodiments the optical amplifiers of the present invention may be used whenever such amplifiers are needed to amplify a light spectrum. as an example, the optical amplifiers of the present invention may be used as subsystem components in optical equipment such as dispersion compensation modules, add / drop modules, switches, receiver modules, transmitter modules, or any other suitable optical communications network equipment. for illustrative purposes, the present invention will be


. an illustrative transmitter 12 and booster amplifier 18 are shown in fig. 4. transmitter 12 may include a number of lasers 36. there may be, for example, 40 or 160 or any other suitable number of lasers in transmitter 12. each laser may operate at a different wavelength that corresponds to one of the channels in a wavelength - division - multiplexing system. lasers 36 may be diode lasers such as distributed feedback lasers. lasers 36 may be directly modulated by control electronics 38 or modulators 40 may be used to modulate the light from lasers 36. modulators 40 may be provided as part of lasers 36 or may be external modulators. suitable external modulators include, for example, high - speed lithium niobate modulators. with the arrangement of fig. 4, data at 10 gbps or 40 gbps or other suitable data rates may be carried on the carrier signals produced by lasers 36. the modulated light carrying the data to be transmitted along link 10 may be provided from the outputs of transmitter 12 to the inputs of booster amplifier 18 over a set of optical fibers 42. fibers 42 may be individual fibers or may be part of one or more ribbon fibers each of which contains multiple fiber paths. the outputs of transmitter 12 and the inputs 18a of booster amplifier 18 may be provided with suitable connectors so that fibers 42 may be connected between transmitter 12 and booster amplifier 18 by a field technician or other suitable personnel. booster amplifier 18 may include a variable optical attenuator multiplexer unit ( voa / mux ) 44 and one or more gain blocks or stages such as gain stage 46. unit 44 may be used to modify the optical spectrum of the optical signals provided at the inputs 18a to amplifier 18. unit 44 may also be used to combine the signals from each of fibers 42 onto a single fiber path 48. the signals on the single fiber path 48 may be amplified by amplifier gain stage 46 and provided as corresponding amplified output signals at output 50. the operation of unit 44 and stage 46 may be controlled using one or more control units such as control unit 52. control unit 52 may be based on any suitable control electronics and may include one or more microprocessors, microcontrollers, digital signal processors, programmable logic devices, application - specific integrated circuits, digital - to - analog converters, analog - to - digital converters, analog control circuits, memory devices, etc. control unit 52 may include communications circuitry for communicating with network equipment.


fundamental physics appears to be entering a new phase. and this new phase has many physicists worried. human curiosity about natural phenomena has always exceeded what was merely necessary for survival. on one hand, this curiosity has led to the generation of elaborate mythologies and religions. on the other, it brought about the ascent of science. the desire to explain the universe, and to make definitive predictions about cosmic phenomena on all scales, has been one of the key drivers of science since the pioneering thinking of galileo, descartes, and newton. the achievements have been truly astounding. in fact, we now have a verifiable " story " for the evolution of the universe from the time it was no more than a minute old to the present. one of the main pillars on which scientists have always constructed their theories ( the so - called " scientific method " ) was falsifiability — theories had to make clear predictions that could be directly tested by experiments or observations. the hope has been, that we can find a theory that would explain not only all the forces that we observe in nature ( gravity, electromagnetism, and two nuclear forces ), but also all the values of all the " constants of nature " ( such as, the relative strength of the forces, the ratio of the masses of the elementary sub - atomic particles, and so on ). in the past two decades, however, ideas started to emerge, that maybe some of the constants of nature are not truly " fundamental ", but rather " accidental. " in other words, instead of one universe, these theories propose, there is really a huge ensemble of universes ( a " multiverse " ). those " accidental " constants take different random values in different members of the ensemble, and the value we happen to observe in our universe is simply one that is consistent with the fact that complexity and life has evolved. this means that there is no true physical explanation to the value of some constants. the details of these models are unimportant. what is important is that all of these parallel universes may be directly unobservable. and this is what keeps many physicists up at night. a huge number of unobservable universes seems to depart from the scientific method into the realm pure metaphysics. to some scientists, admitting that some parts of our universe do not have an explanation from first principles marks the end of fundamental science. well, does it? i don ' t think so. we cannot directly observe free


into the realm pure metaphysics. to some scientists, admitting that some parts of our universe do not have an explanation from first principles marks the end of fundamental science. well, does it? i don ' t think so. we cannot directly observe free quarks ( the constituents of protons ), and yet all physicists believe in their existence. why? because the theory of quarks ( the " standard model " ) makes enough predictions that can be directly verified, so we accept all of its predictions. for the idea of the multiverse and accidental constants to be accepted, it would also have to make a sufficient number of verifiable predictions in the observable universe. if it will not, it will remain as a mere speculation, not a theory. there is also still a chance that physicists will eventually succeed in formulating a theory that does not require the concept of accidental variables. this will clearly be fantastic, and in the spirit of the historical development of science. but we do have to keep an open mind to the possibility that our dream of a " theory of everything " was based on a misunderstanding of what is truly fundamental. in that case, the multiverse may simply mark the beginning of a new and exciting era of scientific thinking, rather than the end of science.


( ho ″ mo - je´ne - ) of uniform quality, composition, or structure. found op http : / / www. encyclo. co. uk / local / 21001 • ( a. ) possessing the same number of factors of a given kind ; as, a homogeneous polynomial. • ( a. ) of the same kind of nature ; consisting of similar parts, or of elements of the like nature ; - - opposed to heterogeneous ; as, homogeneous particles, elements, or principles ; homogeneous bodies... found op http : / / thinkexist. com / dictionary / meaning / homogeneous / ( homo - + gr. genos kind ) consisting of or composed of similar elements or ingredients ; of a uniform quality throughout. found op http : / / users. ugent. be / ~ rvdstich / eugloss / dic / dictio39. html homogeneous 1. having the same kind of constituent elements, or being similar in nature. 2. having a uniform composition or structure. found op http : / / www. wordinfo. info / words / index / info / view _ unit / 2791 / 3 highly similar. discover what it ` s like to live easy with equitrend found op http : / / www. equitrend. com / glossary1744. xhtml 1. having the property that all constituent elements are the same, as a homogeneous good. contrasts with heterogeneous. 2. possessing a certain form of uniformity, as a homogeneous function. found op http : / / www - personal. umich. edu / ~ alandear / glossary / h. html ( or ' homogenous ' ) of uniform nature, similar in kind. 1. in the context of distributed systems, middleware makes heterogeneous systems appear as a homogeneous entity. for example see : interoperable network. constrast heterogeneous. 2. ( mathematics ) ( of a polynomial ) containing terms of the same deg... found op http : / / foldoc. org / homogeneous qualifies a physical medium in which the relevant properties are independent of the position in the medium found op http : / / www. electropedia. org / iev / iev. nsf / display? openform & ievref = 111 - 13 - 08 type : term pronunciation : ho ′ mo - je ′ ne - us definitions : 1. of


www. electropedia. org / iev / iev. nsf / display? openform & ievref = 111 - 13 - 08 type : term pronunciation : ho ′ mo - je ′ ne - us definitions : 1. of uniform structure or composition throughout. 2. consisting of a single phase. found op http : / / www. medilexicon. com / medicaldictionary. php? t = 41355 found op http : / / www. thehorse. com / glossary. xhtml? l = h a substance or material that contains only one kind of compound or one element. homogeneous is latin for " the same kind ". an example of a homogeneous substance would be pure water, which only contains the compound h2o or pure table salt that only contains the compound nacl. found op http : / / www. chemistry - dictionary. com / definition / homogeneous. php [ chemistry ] a substance that is uniform in composition is a definition of homogeneous. this is in contrast to a substance that is heterogeneous. the definition of homogeneous strongly depends on the context used. in chemistry, a homogeneous suspension of material means that when dividing the... found op http : / / en. wikipedia. org / wiki / homogeneous _ ( chemistry ) 1 ) a mixture of the ' same kind, ' like saltwater. 2 ) consistent 3 ) exhibiting a high degree of homogeneity 4 ) homogenised 5 ) homogenized 6 ) homogenous 7 ) same 8 ) solid 9 ) solution, or evenly mixed 10 ) undiversified 11 ) unifo... found op http : / / www. mijnwoordenboek. nl / en / crossword - dictionary / homogeneous / 1 tip : double click on a word to show its meaning. no exact matches found. typ a word and hit ` search `. the most recent searches on encyclo. between brackets you will find the number of results and number of related results. • charles s. lawrence ( 1 ) • sauer heiner ( 1 ) • malatya ( 5 ) • cbd metro ( 1 ) • cardioneurosis ( 2 ) • lotus ononopsis ( 1 ) • hurricane ( 25 ) • calisto smintheus ( 1 ) • turbidity ( 18 ) • bunyoro ( 2 ) • left hepatic vein ( 2 ) • pahor, borut ( 1 ) • theo


cold regions science and technology cold regions science and technology is an international journal dealing with the scientific and technical problems of cold environments in both the arctic and more temperate locations. the primary focus is with problems related to the freezing of water, and especially with the many forms of floating ice, snow, and frozen ground. the journal serves a wide range of specialists, providing a medium for interdisciplinary communication and a convenient source of reference. emphasis is given to applied science with broad coverage of the physics, chemistry, mechanics, and biological aspects of ice, snow, ice - water systems, and ice - bonded soils. relevant aspects of earth science, materials science, offshore and river ice engineering are also of primary interest. technological advances for cold regions areas in research, development, and engineering practice are relevant to the journal. this includes traditional major specializations of engineering ( civil, mechanical, electrical ), together with other engineering subdivisions ( e. g. hydraulics, biotechnology, agricultural, mining, highway, sanitary, petroleum, ocean, rivers ). coverage may also include engineering geology, architecture, meteorology, hydrology, forestry, exploration geophysics, naval architecture, and so forth. theoretical papers must include a detailed discussion of the potential application of the theory to address cold regions problems. benefits to authors we also provide many author benefits, such as free pdfs, a liberal copyright policy, special discounts on elsevier publications and much more. please click here for more information on our author services.


: engage, explore, explain, elaborate, and evaluate. these are lessons “ for the teacher. ” their design is such that it helps you to increase your content knowledge in a developmental and interesting fashion. however, as with most lessons you receive as a teacher, there is always something for you to take with you to your classroom. sometimes these “ take homes ” are things you should do, and sometimes they are things you should not do. fortunately, the approach to the scipacks lessons are things you should do. they display intricate questions, that even in a multiple choice format, force you to consider what is going on in the whole scenario. in addition, you must possess a thorough understanding of the information in order to answer them successfully. i like the interactive graphics and believe they could be used with a projector to demonstrate concepts to your own class. they could also be used in what i like to call a reflective prediction scenario, where you ask the students “ what will happen if ” and then discuss their predictions and the results. scipacks are five - to ten - hour discrete learning experiences teachers can use to quickly enhance their understanding of a particular scientific concept. teachers can access any topic “ on demand ” at any time from any computer connected to the internet. topics are based on the science literacy goals in the national standards ( nses, science for all americans, benchmarks, and the atlas of scientific literacy ) and tied to state standards. the scipacks are bundled science objects with the added bonus that the person using scipacks is able to ask questions to experts. when you take the science object quizzes and miss a question, there is an explanation as to why an answer is correct. if you have purchased a scipack, and you need further understanding, you will have an opportunity to ask questions to an expert. these units are designed with continuing education needs in mind, and end with an assessment of what you have learned. when the assessment has been satisfactorily completed, the program generates a certificate of achievement signed the by the nsta executive director. freebies for science teachers freebies for science teachers contains links to websites that offer online activities, hands - on activities / materials, information, and resources in a variety of formats from online videos to podcasts. each link includes a brief overview of what the site provides. the freebies section is a diverse collection of many different resources that may start out as a web page, but move out from there to provide contacts for instructional materials, posters, organizational membership


what exactly is " intelligent design? when one considers the vast complexity of the universe, it is natural to question its origin and how it was formed. was it by some great design? don ' t miss the last two paragraphs! the galaxies, stars and planets are all made of matter. but what is " matter "? what is an atom? why are objects attracted to one another by the force of gravity and what is gravity? is there some supreme being that invented the universe? this question has not been answered by today ' s science. however, there are various patterns that we now recognize by observation, measurement and physical models of science. in fact, sophisticated pattern recognition ( mandelbrot theory ) is being explored by scientists as a new scientific method of analysis for the complexity of outer space. the hydrogen atom consists of only two electric particles : an electron and a proton, and yet these little devices have some amazing properties. this atom can form itself from these two electric charges, and it can also be disassembled and later reassembled. atoms communicate with one another, even at great distances although to a smaller degree. some 80 % of the universe is filled with hydrogen atoms, and most of the rest is an assemblage of electric particles in the form of plasma gases. therefore, two of the primary elements of the universe are the electron and the proton, neither of which have ever been viewed ( although we are getting close to having that capability ). these little " things " deserve some consideration. the electron and the proton gyrate, producing little electromagnetic whirlpools. the electron rotates one million, million million times a second ( physicists may quibble about this high frequency estimate ). we do not yet have the capability to measure this internal frequency. however, the wavelength is in the low ultraviolet region, which is the equivalent amount of energy that escapes from an electron when the atom is blasted by high energy. the proton frequency is much higher, and its emission wavelength is correspondingly much shorter. this frequency also correlates with wavelength measurements from a proton that is bombarded with high - energy particles. the affinity between the electron and the proton is very great. unbelievably great. when atoms are blasted apart, the electrons and protons can separate from one another. in any type of matter there are generally many, many electrons and protons. in 12 grams of carbon - 12, there are almost one million, million, million million atoms. if we pull those atoms


and protons can separate from one another. in any type of matter there are generally many, many electrons and protons. in 12 grams of carbon - 12, there are almost one million, million, million million atoms. if we pull those atoms apart and separate the electrons and protons, the force between them is unbelievably enormous ( see the penny puzzle ). in every atom, there are an even number of electrons and protons, so the external electric forces tend to cancel. however, there is a tiny bit of force that is left over that we know as " the force of gravity " ( see the secret of gravity ). having an equal number of electrons and protons, each atom consists of a number of hydrogen atoms ( another way to look at the problem that physicists probably wouldn ' t appreciate ). the neutron is simply a compressed hydrogen atom that is rather unstable by itself. the neutrons associate closely with the protons in an atom, so the nucleus can acquire additional neutrons, and the new atoms are called " isotopes ". with these considerations, we can view all types of mass as an assemblage ( of one sort or another ) of hydrogen atoms. an atom can also gain or lose a few electrons, thus creating ions. the point is that all mass consists of electrons and protons and in pairs ( hydrogen atoms ). the internal workings of these atoms can be incredibly complex, with all sorts of orbit paths and resonances. my present endeavor, to analyze these workings. in any case, it becomes clear that we need to understand hydrogen in order to understand the universe, and it only consists of two tiny particles! what an incredible and highly intelligent design! the models of electrons, protons and atoms were all devised from a vast number of measurements. these measurements are of the force fields that surround them and the dynamic electromagnetic fields that they create. some of that energy can escape into space. the antenna radiation equations date back at least to 1936 ( mesny ), and they are extremely important in understanding physical phenomena. the two charges of the hydrogen atom are separated, and we call that a " electric dipole ". this dipole has an electric field around it that can be, and has been, measured extensively. the two charges attract one another, and the closer they get, the greater the force. these properties are defined by a single mathematical equation that we call " coulomb ' s law ". it is ( arguably ) the most important scientific relationship in existence


two charges attract one another, and the closer they get, the greater the force. these properties are defined by a single mathematical equation that we call " coulomb ' s law ". it is ( arguably ) the most important scientific relationship in existence, and yet it is quite old. it is a well - proven law and has always been highly accurate. it has hardly changed over the past centuries. the great scientist, max planck, called this and other such laws that maintain themselves with time, " invariants ". this formed the the basis for his famous radiation equation and fundamental quantum theory. therefore, we can add these factors to our basic fundamentals, along with the electron and proton. we can also add clausius ' s concept of " entropy " which expresses the preference in nature for a given energy state, and boltzmann ' s laws of thermodynamics for gases and solids. we will then need the laws of probability, which have never been proven but work out quite well. these laws apply to the probabilistic motions of free atoms and electrons. in the field of electromagnetics, there are a number of fundamental laws and equations. however, most all of them depend upon the laws mentioned above. max planck ' s radiation equation is essential in assessing the characteristics of electron noise, heat radiation, physical and chemical stable energy states, and radiation from a heated body. we can also include ohm ' s law for electrical resistance, gauss ' s law for the magnetic field, maxwell ' s equations for field waves, ampere ' s law for electron current, henry ' s law for electrical inductance, faraday ' s laws of chemistry and electrical capacitance, joule for defining energy. bohr ' s theory for the atom is quite useful but has a fatal flaw in that it is abstract. there are also a number of others. there are several basic laws of importance that we will also need in order to support the concept of intelligent design. one of them states that " an object in motion tends to stay in motion ". this is the law of ' inertia ". as to the laws of electromagnetism, we can add the law of " biot - savart " that relates the magnetic field that is created by moving electrons. most all of the laws of electronic engineering depend on this law. combining it with coulomb ' s law results in the lorentz force equation, so we don ' t really need to add lorentz ' s equation to


created by moving electrons. most all of the laws of electronic engineering depend on this law. combining it with coulomb ' s law results in the lorentz force equation, so we don ' t really need to add lorentz ' s equation to our pantry. another fundamental and perhaps the most important invariant is " the law of least action " ( may be called the " law of least - known " ), which was originally based on mechanics but can be applied to electrodynamics, thermodynamics, potential, time and space. objects tend to move in the direction of least energy. planck described this law as interpreted by helmholtz and stated that it plays the principal role in the interpretation of all physical laws. this law can be written in the form of an integral equation that represents the conservation of energy. the sum of the external work is equal to the extra energy expended in a process. there can be extra stored energy ( in a system ) that is not an essential part of this equation since it does no work and is not expended. details on this can be found in planck ' s columbia lectures, lecture vii. so that ' s it. the two main elements of the universe are the electron and the proton. the forces acting on them, the direction, velocity and acceleration, all as described above. the principal of least action is of greatest importance in fact, helmholtz believed that it is fundamental to the unification of the system of theoretical physics, since it connects together the elementary quantities by which physical phenomena are measured. it connects together the elementary quantities by which physical phenomena are measured and from which physical laws can be interpreted. it describes how electrical charges form masses, how motion occurs and how mass is created and destroyed. " it connects together in a single equation the relationships between quantities which possess, not only for mechanics, the quantities space, time and potential ". two major concepts are included in this theory : ( 1 ) and action in motion tends to stay in motion, and ( 2 ) an action takes the direction of least force and least energy. these actions and reactions form a universe of what we can accept as an " intelligent design ". but where did it come from, and how was it created? the answers to this last question are simply " beliefs ". the last part of this story is a mystery yet to be solved. if you like this article, see our main page index for more interesting information!