electrophoresis is a common lab technique used to identify, quantify, and purify nucleic acid fragments and assess quality. rna molecules are negatively charged, and during gel electrophoresis they migrate toward the anode in the presence of an electric current. the length of rna generally determines its migration in the gel, since longer rna molecules move slower than shorter fragments. however, rna molecules are subject to extensive secondary structure via intramolecular base pairing, and this can affect their gel migration. for most applications, rna is run using denaturing conditions to disrupt secondary structure. for applications such as resolving different conformations of rna, native ( or nondenaturing ) gels are recommended. nondenaturing rna electrophoresis gel electrophoresis of rna under nondenaturing conditions maintains the secondary structure of rna molecules. agarose is generally preferred to acrylamide because it has lower toxicity and, at the concentrations needed to resolve typical rna molecules, it is easier to handle. life technologies offers convenient reagents for nondenaturing agarose gel electrophoresis, including hassle - free precast e - gel® agarose gels and ultrapure™ reagents to pour your own agarose gels. products for nondenaturing rna electrophoresis : denaturing rna electrophoresis to accurately determine the molecular weight of rna molecules, it is essential to run rna gels using denaturing conditions. since northern blots typically seek to characterize rna molecules based on their size, denaturing electrophoresis is commonly used prior to rna analysis by northern blotting.. denaturing conditions disrupt hydrogen bonding so that rna runs without secondary structure, as single - stranded molecules. there are a number of denaturing agents available, including glyoxal, formamide, and methyl mercury. the disadvantage of these compounds is that they are toxic and therefore should be treated with caution. traditionally, formaldehyde has been used as a denaturant for rna electrophoresis. the northernmax® kit contains a complete set of rnase - free reagents for running formaldehyde - containing agarose gels. these gels must be poured and run in a fume hood. with the northernmax® - gly kit, rna samples are denatured in glyoxal / dmso loading buffer prior to electrophoresis and run in a formal


deoxidation is the removal of excess oxygen from molten metal. the procedure involves adding materials with a high affinity for oxygen, the oxides of which are either gaseous or readily form slags. the deoxidation of steel is usually performed by adding mn, si and al, or rarely by adding cr, v, ti, zr and b. the deoxidation of molten steel shows a paradox. by increasing the concentration of deoxidizer in the melt over some critical value reoxidation of steel takes place. a few examples of the reoxidation of steel by adding the usual deoxidizers ( si and al ) are examined in this article. deoxidation is the last stage in steelmaking. in the basic oxygen furnace ( bof ) and other similar steelmaking practices the steel bath as the time of tapping contains 400 to 800 ppm activity of oxygen. deoxidation is carried out during tapping by adding into the tap - ladle appropriate amounts of ferromanganese, ferrosilicon and / or aluminum or other special deoxidizers. if at the end of the blow the carbon content of the steel is below specifications, the metal is also recarburized in the ladle. however, large additions in the ladle are undesirable, because of the adverse effect on the temperature of the metal. eight typical conditions of commercial ingots, cast in identical bottle - top molds, in relation to the degree of suppression of gas evolution are shown schematically in figure 1. the dotted line indicates the height to which the steel originally was poured in each ingot mold. depending on the carbon content and particularly of the oxygen content, the ingot structures range from that of a fully killed or dead - killed ingot n°1 to that of a violently rimmed ingot n°8. included in the series are indicated in figure 1 i. e. killed steel n°1, semikilled steel n°2, capped steel n°5, and rimmed steel n°7. figure 1 : series of typical ingot structures rimmed steel usually is tapped without having made additions of deoxidizers to the steel in the furnace or only small additions to the molten steel in ladle, in order to have sufficient oxygen present to give the desired gas evolution by reacting in the mold with carbon. the exact procedures followed depend upon whether the steel has a carbon content in the higher ranges i. e. % c =


steel in ladle, in order to have sufficient oxygen present to give the desired gas evolution by reacting in the mold with carbon. the exact procedures followed depend upon whether the steel has a carbon content in the higher ranges i. e. % c = 0. 12 - 0. 15 or in the lower ranges, e. g. % c = max 0. 10. when the metal in the ingot mold begins to solidify, there is a brisk evolution of carbon monoxide, resulting in an outer ingot skin of relatively clean metal low in carbon and other solutes. such ingots are best suited for the manufacture of steel sheets. capped steel practice is a variation of rimmed steel practice. the rimming action is allowed to begin normally, but is then terminated after a minute or more by sealing the mold with a cast - iron cap. in steels with a carbon content greater than 0. 15 % the capped ingot practice is usually applied to sheet, strip, wire and bars. semikilled steel is deoxidized less than killed steel and there is enough oxygen present in the molten steel to react with carbon forming sufficient carbon monoxide to counterbalance the solidification shrinkage. the steel generally has a carbon content within the range % c = 0. 15 - 0. 30 and finds wide application in structural shapes. killed steel is deoxidized to such an extent that there is no gas evolution during solidification. aluminum is used for deoxidation, together with ferro - alloys of manganese and silicon ; in certain cases calcium silicide or other special strong deoxidizers are used. in order to minimize piping, almost all killed steels are cast in hot - topped big - end up molds. killed steels are generally used when a homogeneous structure is required in the finished steels. alloy steels, forging steels and steels for carburizing are of this type, when the essential quality is soundness. in producing certain extra - deep - drawing steels, a low - carbon ( % c = max 0. 12 ) steel is killed, usually with a substantial amount of aluminum that is added in the ladle, in the mold or both. although the deoxidation of steel by aluminum suppresses the formation of carbon monoxide during solidification, and hence suppresses blow holes, there are many steel processing operations where aluminum killing of steel is undesirable. for example, it is widely recognized that certain alloy steels to


aluminum suppresses the formation of carbon monoxide during solidification, and hence suppresses blow holes, there are many steel processing operations where aluminum killing of steel is undesirable. for example, it is widely recognized that certain alloy steels to be cast as large ingots should not be subject to aluminum killing, because of the piping and of deleterious effects of alumina inclusions on the subsequent processing of ingots for certain applications, e. g. generator - rotor shafts. it has been recognized from the early days of the continuous - casting operation nearly two decades ago that casting difficulties and poor surface conditions are often experienced with aluminum - killed steels. it is for these reasons that other forms of deoxidation are often preferred in a number of steel - processing operations, e. g. silico - managanese deoxidation and / or vacuum carbon deoxidation. deoxidation reactions can be described using the deoxidation equilibrium constant. a wide spectrum of deoxidation equilibria pertaining to the most common deoxidants for steel is summarized in table 1 as a log - log plot of the concentration of oxygen in solution in liquid steel against that of the added elements. table 1 : solubility of the products of deoxidation in liquid iron. | equilibrium constant k * | | k at 1600°c | | < 1 ppm al | | 1. 1 x 10 - 15 | | - 71600 / t + 23. 28 | | < 1 ppm al | | 4. 3 x 10 - 14 | | - 62780 / t + 20. 17 | | 1. 3 x 10 - 8 | | > 0. 02 % c | | 2. 0 x 10 - 3 | | - 1168 / t - 2. 07 | | > 3 % cr | | 1. 1 x 10 - 4 | | - 40740 / t + 17. 78 | | > 1 % mn | | 5. 1 x 10 - 2 | | - 14450 / t + 6. 43 | | > 20 ppm si | | 2. 2 x 10 - 5 | | - 30410 / t + 11. 59 | | < 0. 3 % ti | | 2. 8 x 10 - 6 | | > 5 % ti | | 1. 9 x 10 - 3 | | < 0. 10 v | | 8. 9 x 10 - 8 | | - 48060 / t +


% ti | | 2. 8 x 10 - 6 | | > 5 % ti | | 1. 9 x 10 - 3 | | < 0. 10 v | | 8. 9 x 10 - 8 | | - 48060 / t + 18. 61 | | > 0. 3 % v | | 2. 9 x 10 - 6 | | - 43200 / t + 17. 52 in all cases, the oxygen and the alloying element in solution are in equilibrium with the appropriate gas, liquid or solid oxide phases at 1600°c, e. g. 1 atm co, pure b2o3, pure al2o3 etc. the curves for mn, si and c are from compiled data. the curves for cr, v, b, ti and al are based on the recent work done in this laboratory by fruehan using the oxygen galvanic cell previously described in measuring the equilibrium oxygen potentials. - activities are chosen such that amn ≡ % mn and ao ≡ % o when % m→o - square brackets [ ] denote component present in molten steel - temperature ( t ) is on the kelvin scale. deoxidation reactions can be described using the deoxidation equilibrium constant. the reaction when the alloying element ( m ) is added to the steel can be represented by : mxoy = xm + yo..... ( 1 ) the deoxidation constant assuming pure mxoy forms ( i. e. unit activity for mxoy ) is given by : k = ( hm ) x ( ho ) y..... ( 2 ) where hm and ho are the henrian activities defined such that activity of the components is equal to its weight percent at infinite dilution in iron. hi = fi ( wt. % i )..... ( 3 ) the activity coefficient fi can be corrected for alloying elements by use of the interaction parameter eji ( d log fi / d log wt % j ) = eji..... ( 4 ) table 2 shows the coefficients of interaction for the common elements of carbon and stainless steels at 1600°c. table 2 : the coefficients of interaction for the common elements of carbon and stainless steels at 1600°c | carbon steel 1600°c | stainless steel 1600°c for most low alloy steels encountered in ladle metallurgy the activity coefficient can be taken as unity and equation 2 reduces to : km = ( % m ) x ( % o ) y.


electricity and magnetism the dot product introduction to the vector dot product. the dot product use this menu to view and help create subtitles for this video in many different languages. you ' ll probably want to hide youtube ' s captions if using these subtitles. - let ' s learn a little bit about the dot product. - the dot product, frankly, out of the two ways of multiplying - vectors, i think is the easier one. - so what does the dot product do? - why don ' t i give you the definition, and then i ' ll give - you an intuition. - so if i have two vectors ; vector a dot vector b - - that ' s - how i draw my arrows. - i can draw my arrows like that. - that is equal to the magnitude of vector a times the - magnitude of vector b times cosine of the - angle between them. - now where does this come from? - this might seem a little arbitrary, but i think with a - visual explanation, it will make a little bit more sense. - so let me draw, arbitrarily, these two vectors. - so that is my vector a - - nice big and fat vector. - it ' s good for showing the point. - and let me draw vector b like that. - vector b. - and then let me draw the cosine, or let me, at least, - draw the angle between them. - this is theta. - so there ' s two ways of view this. - let me label them. - this is vector a. - i ' m trying to be color consistent. - this is vector b. - so there ' s two ways of viewing this product. - you could view it as vector a - - because multiplication is - associative, you could switch the order. - so this could also be written as, the magnitude of vector a - times cosine of theta, times - - and i ' ll do it in color - appropriate - - vector b. - and this times, this is the dot product. - i almost don ' t have to write it. - this is just regular multiplication, because these - are all scalar quantities. - when you see the dot between vectors, you ' re talking about - the vector dot product. - so if we were to just rearrange this expression this - way, what does it mean? - what is a cosine of theta? - let me


the dot between vectors, you ' re talking about - the vector dot product. - so if we were to just rearrange this expression this - way, what does it mean? - what is a cosine of theta? - let me ask you a question. - if i were to drop a right angle, right here, - perpendicular to b - - so let ' s just drop a right angle - there - - cosine of theta soh - coh - toa so, cah cosine - - - is equal to adjacent of a hypotenuse, right? - well, what ' s the adjacent? - it ' s equal to this. - and the hypotenuse is equal to the magnitude of a, right? - let me re - write that. - so cosine of theta - - and this applies to the a vector. - cosine of theta of this angle is equal to ajacent, which - is - - i don ' t know what you could call this - - let ' s call - this the projection of a onto b. - it ' s like if you were to shine a light perpendicular to b - - - if there was a light source here and the light was - straight down, it would be the shadow of a onto b. - or you could almost think of it as the part of a that goes - in the same direction of b. - so this projection, they call it - - at least the way i get - the intuition of what a projection is, i kind of view - it as a shadow. - if you had a light source that came up perpendicular, what - would be the shadow of that vector on to this one? - so if you think about it, this shadow right here - - you could - call that, the projection of a onto b. - or, i don ' t know. - let ' s just call it, a sub b. - and it ' s the magnitude of it, right? - it ' s how much of vector a goes on vector b over - - that ' s the - adjacent side - - over the hypotenuse. - the hypotenuse is just the magnitude of vector a. - it ' s just our basic calculus. - or another way you could view it, just multiply both sides - by the magnitude of vector a. - you get the projection of a onto b, which is just a fancy -


vector a. - it ' s just our basic calculus. - or another way you could view it, just multiply both sides - by the magnitude of vector a. - you get the projection of a onto b, which is just a fancy - way of saying, this side ; the part of a that goes in the - same direction as b - - is another way to say it - - is - equal to just multiplying both sides times the magnitude of a - is equal to the magnitude of a, cosine of theta. - which is exactly what we have up here. - and the definition of the dot product. - so another way of visualizing the dot product is, you could - replace this term with the magnitude of the projection of - a onto b - - which is just this - - times the - magnitude of b. - that ' s interesting. - all the dot product of two vectors is - - let ' s just take - one vector. - let ' s figure out how much of that vector - - what component - of it ' s magnitude - - goes in the same direction as the - other vector, and let ' s just multiply them. - and where is that useful? - well, think about it. - what about work? - when we learned work in physics? - work is force times distance. - but it ' s not just the total force - times the total distance. - it ' s the force going in the same - direction as the distance. - you should review the physics playlist if you ' re watching - this within the calculus playlist. let ' s say i have a - 10 newton object. - it ' s sitting on ice, so there ' s no friction. - we don ' t want to worry about fiction right now. - and let ' s say i pull on it. - let ' s say my force vector - - this is my force vector. - let ' s say my force vector is 100 newtons. - i ' m making the numbers up. - 100 newtons. - and let ' s say i slide it to the right, so my distance - vector is 10 meters parallel to the ground. - and the angle between them is equal to 60 degrees, which is - the same thing is pi over 3. - we ' ll stick to degrees. - it ' s a little bit more intuitive. - it ' s 60 degrees. - this distance right here is 10 meters. - so my question is,


is - the same thing is pi over 3. - we ' ll stick to degrees. - it ' s a little bit more intuitive. - it ' s 60 degrees. - this distance right here is 10 meters. - so my question is, by pulling on this rope, or whatever, at - the 60 degree angle, with a force of 100 newtons, and - pulling this block to the right for 10 meters, how much - work am i doing? - well, work is force times the distance, but not just the - total force. - the magnitude of the force in the direction of the distance. - so what ' s the magnitude of the force in the - direction of the distance? - it would be the horizontal component of this force - vector, right? - so it would be 100 newtons times the - cosine of 60 degrees. - it will tell you how much of that 100 - newtons goes to the right. - or another way you could view it if this - is the force vector. - and this down here is the distance vector. - you could say that the total work you performed is equal to - the force vector dot the distance vector, using the dot - product - - taking the dot product, to the force and the - distance factor. - and we know that the definition is the magnitude of - the force vector, which is 100 newtons, times the magnitude - of the distance vector, which is 10 meters, times the cosine - of the angle between them. - cosine of the angle is 60 degrees. - so that ' s equal to 1, 000 newton meters - times cosine of 60. - cosine of 60 is what? - it ' s square root of 3 over 2. - square root of 3 over 2, if i remember correctly. - so times the square root of 3 over 2. - so the 2 becomes 500. - so it becomes 500 square roots of 3 joules, whatever that is. - i don ' t know 700 something, i ' m guessing. - maybe it ' s 800 something. - i ' m not quite sure. - but the important thing to realize is that the dot - product is useful. - it applies to work. - it actually calculates what component of what vector goes - in the other direction. - now you could interpret it the other way. - you could say this is the magnitude of a - times b cosine of theta. - and that ' s


it actually calculates what component of what vector goes - in the other direction. - now you could interpret it the other way. - you could say this is the magnitude of a - times b cosine of theta. - and that ' s completely valid. - and what ' s b cosine of theta? - well, if you took b cosine of theta, and you could work this - out as an exercise for yourself, that ' s the amount of - the magnitude of the b vector that ' s - going in the a direction. - so it doesn ' t matter what order you go. - so when you take the cross product, it matters whether - you do a cross b, or b cross a. - but when you ' re doing the dot product, it doesn ' t matter - what order. - so b cosine theta would be the magnitude of vector b that - goes in the direction of a. - so if you were to draw a perpendicular line here, b - cosine theta would be this vector. - that would be b cosine theta. - the magnitude of b cosine theta. - so you could say how much of vector b goes in the same - direction as a? - then multiply the two magnitudes. - or you could say how much of vector a goes in the same - direction is vector b? - and then multiply the two magnitudes. - and now, this is, i think, a good time to just make sure - you understand the difference between the dot product and - the cross product. - the dot product ends up with just a number. - you multiply two vectors and all you have is a number. - you end up with just a scalar quantity. - and why is that interesting? - well, it tells you how much do these - - you could almost say - - - these vectors reinforce each other. - because you ' re taking the parts of their magnitudes that - go in the same direction and multiplying them. - the cross product is actually almost the opposite. - you ' re taking their orthogonal components, right? - the difference was, this was a a sine of theta. - i don ' t want to mess you up this picture too much. - but you should review the cross product videos. - and i ' ll do another video where i actually compare and - contrast them. - but the cross product is, you ' re saying, let ' s multi


you up this picture too much. - but you should review the cross product videos. - and i ' ll do another video where i actually compare and - contrast them. - but the cross product is, you ' re saying, let ' s multiply - the magnitudes of the vectors that are perpendicular to each - other, that aren ' t going in the same direction, that are - actually orthogonal to each other. - and then, you have to pick a direction since you ' re not - saying, well, the same direction that - they ' re both going in. - so you ' re picking the direction that ' s orthogonal to - both vectors. - and then, that ' s why the orientation matters and you - have to take the right hand rule, because there ' s actually - two vectors that are perpendicular to any other two - vectors in three dimensions. - anyway, i ' m all out of time. - i ' ll continue this, hopefully not too confusing, discussion - in the next video. - i ' ll compare and contrast the cross - product and the dot product. - see you in the next video. be specific, and indicate a time in the video : at 5 : 31, how is the moon large enough to block the sun? isn ' t the sun way larger? have something that ' s not a question about this content? this discussion area is not meant for answering homework questions. share a tip when naming a variable, it is okay to use most letters, but some are reserved, like ' e ', which represents the value 2. 7831... have something that ' s not a tip or feedback about this content? this discussion area is not meant for answering homework questions. discuss the site for general discussions about khan academy, visit our reddit discussion page. flag inappropriate posts here are posts to avoid making. if you do encounter them, flag them for attention from our guardians. - disrespectful or offensive - an advertisement - low quality - not about the video topic - soliciting votes or seeking badges - a homework question - a duplicate answer - repeatedly making the same post - a tip or feedback in questions - a question in tips & feedback - an answer that should be its own question about the site


a wide - ranging study of language, including the various political dimensions involved in how and why certain languages gain prestige while others become extinct. how have industrialization and nationalism shaped language variation worldwide? is the writing system a natural outgrowth of speech, or can it simply be changed by government edict? is there really one correct way of speaking english? is the french language being threatened? are chinese characters really based on pictographs? these are just a handful of the many intriguing questions, issues and “ linguistic myths ” that economist contributor greene investigates in this fascinating glimpse at the global politics of language variation. essentially, the book is a course in sociolinguistics and modern international language politics for the layperson. the author, who speaks nine languages, begins by dispelling a variety of language myths that are pervasive and, to the chagrin of many linguists, seemingly unshakeable — that some languages are more primitive than others, that the qur ’ an cannot be translated from arabic, or that the maori of new zealand have 35 words for dung. greene also exposes grammar sticklers — people who are obsessively determined to “ purify ” language and who are nostalgic for a linguistic utopia that never existed — for the persnickety and curmudgeonly group they really are. the author blends personal narrative, reportage and humor with linguistic analysis, historical research and political punditry, and he surveys some of the most significant issues concerning language today, including the ethnocentrism involved in some english - only activism in america, as well as the draconian — and largely unsuccessful — measures of the french academy to keep french free of english words. greene correctly demonstrates that language change, language variety and cross - language borrowing are “ highly regular ” and, in fact, part of the natural evolution of all languages. an insightful, accessible examination of the way in which day - to - day speech is tangled in a complicated web of history, politics, race, economics and power.


worm, the cabbage looper ( trichoplusia ni ). the larvae act as bioreactors and produce in large amounts – and at a much lower cost than conventional reactors based on microorganisms – the proteins which code these genes, and which are responsible for a protective response in vaccinated individuals. using this method, a dna vaccine can be manufactured with the protozoan protein coding genes, and a second vaccine with proteins associated with these genes ( produced at a low cost using insect larvae ), with the aim of increasing its effectiveness. this vaccine strategy can be used both in a preventive and a therapeutic manner, in both humans and dogs. presently, the possibility of a translational phase is being contemplated with the aim of transferring as quickly as possible the results of this basic research to clinical practices, and of increasing the efficacy even more by using drugs to boost the immune response. todoli f., rodriguez - cortes a., nunez m. del carmen, laurenti m. d., gomez - sebastian s., et al. ( 2012 ) " head - to - head comparison of three vaccination strategies based on dna and raw insect - derived recombinant proteins against leishmania. " plos one 7 ( 12 ) : e51181. doi : 10. 1371 / journal. pone. 0009617 universitat autonoma de barcelona : http : / / www. uab. es this press release was posted to serve as a topic for discussion. please comment below. we try our best to only post press releases that are associated with peer reviewed scientific literature. critical discussions of the research are appreciated. if you need help finding a link to the original article, please contact us on twitter or via e - mail.


study guide – anthropology 104 note : this is just a guide! any material covered in class, class discussion, videos, or in readings and home work could be incorporated in the midterm or final. this is not a complete summary of all you will need to know in this course. chapter one : what is anthropology? what are the subfields of anthropology? in what way is anthropology holistic, comparative, field work based? what is a frame of reference? what is ethnocentrism? cultural relativism? who was one of the most influential founders of american anthropology? what ethical concerns do anthropologists have? what is theoretical linguistics? how does linguistic anthropology differ from theoretical linguistics? why are anthropologists interested in language? chapter two : why do the inuit have so many words for seals, ice and snow? what is ethnosemantics? cognitive anthropology? ethnoscience? what is a semantic domain? what is “ the new ethnography? ” what is linguistic relativity? what is linguistic determinism? what is the sapir - whorf hypothesis? what is a “ mental map ”? what are anthropologists interested in areas of linguistic emphasis? what does the hanunoo color system tell us about the hanunoo? does language affect the way we respond to the material world? chapter three : what is phonology? phonetics? phonemics? what are the differences between acoustic phonetics, auditory phonetics, articulatory phonetics and descriptive phonetics? what is voicing? based on the place of articulation, what are the various ways consonants can be articulated? what are the various manners in which consonants can be articulated? what information do we need to know how a consonant is made or sounds? what information do we need to know how a vowel is formed? what is “ rounding ”. what is tongue height, tongue place? what are phonenes? what are allophones? what is “ complementary distribution ”? what does ipa stand for? what is the point of the ipa? what is a minimal pair. chapter four : what is morphology? what is syntax? what is a morpheme? what is a word? what is a base? what is a root? stem? affix? what is a hierarchy in terms of affixes? how are new words created? what is inflection? what is derivation? what are transformational rules, what is generative grammar? what is prescriptive grammar? what is


how do children acquire language? what is broca ’ s area of the brain? what is wernicke ’ s area? chapter nine : what are the various causes of language change? what is a dialect? what is a language? what is the origin of most european languages? how are new words developed ( lecture )? what is a pidgin? what is a creole? why did the oakland school district want to teach in ebonics? why did that upset people? what is codeswitching? what was the great vowel shift? chapter ten : what is an endangered language? what is language extinction? what are marked forms, and unmarked forms? how can there be bias in grammar? in what ways can language be sexist or racist? can language be sexist even if there are no negative words concerning women? do anthropologists have many opportunities to study language and language use in their daily lives? don ’ t forget the readings in the work book, as well! | 3123 | | anthro 104 | | m | | 03 : 30 pm - 06 : 40 pm | | cms 004 | | closed | | syllabus | | no courses are available yet for this semester. please check back later. | 3027 | | anthro 104 | | m | | 03 : 30 pm - 06 : 40 pm | | cms 004 | | open | |


hacking quantum cryptography just got harder with quantum encryption, in which a message gets encoded in bits represented by particles in different states, a secret message can remain secure even if the system is compromised by a malicious hacker. credit : margita | shutterstock vancouver, british columbia — no matter how complex they are, most secret codes turn out to be breakable. producing the ultimate secure code may require encoding a secret message inside the quantum relationship between atoms, scientists say. artur ekert, director of the center for quantum technologies at the national university of singapore, presented the new findings here at the annual meeting of the american association for the advancement of science. ekert, speaking saturday ( feb. 18 ), described how decoders can adjust for a compromised encryption device, as long as they know the degree of compromise. the subject of subatomic particles is a large step away from the use of papyrus, the ancient writing material employed in the first known cryptographic device. that device, called a scytale, was used in 400 b. c. by spartan military commanders to send coded messages to one another. the commanders would wrap strips of papyrus around a wooden baton and write the message across the strips so that it could be read only when the strips were wrapped around a baton of matching size. [ the coolest quantum particles explained ] later, the technique of substitution was developed, in which the entire alphabet would be shifted, say, three characters to the right, so than an " a " would be replaced by " d, " and " b " replaced by " e, " and so on. only someone who knew the substitution rule could read the message. julius caesar employed such a cipher scheme in the first century b. c. over time, ciphers became more and more complicated, so that they were harder and harder to crack. harder, but not impossible. " when you look at the history of cryptography, you come up with a system, and sooner or later someone else comes up with a way of breaking the system, " ekert said. " you may ask yourself : is it going to be like this forever? is there such a thing as the perfect cipher? " the perfect cipher the closest thing to a perfect cipher involves what ' s called a one - time pad. " you just write your message as a sequence of bits and you then add those bits to a key and obtain a cryptogram, " ekert said. " if you take the cryptogram and add it to the key, you


pad. " you just write your message as a sequence of bits and you then add those bits to a key and obtain a cryptogram, " ekert said. " if you take the cryptogram and add it to the key, you get plain text. in fact, one can prove that if the keys are random and as long as the messages, then the system offers perfect security. " in theory, it ' s a great solution, but in practice, it has been hard to achieve. [ 10 best encryption software products ] " if the keys are as long as the message, then you need a secure way to distribute the key, " ekert said. the nature of physics known as quantum mechanics seems to offer the best hope of knowing whether a key is secure. quantum mechanics says that certain properties of subatomic particles can ' t be measured without disturbing the particles and changing the outcome. in essence, a particle exists in a state of indecision until a measurement is made, forcing it to choose one state or another. thus, if someone made a measurement of the particle, it would irrevocably change the particle. if an encryption key were encoded in bits represented by particles in different states, it would be immediately obvious when a key was not secure because the measurement made to hack the key would have changed the key. this, of course, still depends on the ability of the two parties sending and receiving the message to be able to independently choose what to measure, using a truly random number generator — in other words, exercising free will — and using devices they trust. but what if a hacker were controlling one of the parties, or tampering with the encryption device? ekert and his colleagues showed that even in this case, if the messaging parties still have some free will, their code could remain secure as long as they know to what degree they are compromised. in other words, a random number generator that is not truly random can still be used to send an undecipherable secret message, as long as the sender knows how random it is and adjusts for that fact. " even if they are manipulated, as long as they are not stupid and have a little bit of free will, they can still do it, " ekert said. more from livescience. com


click any word in a definition or example to find the entry for that word 90 % of the time, speakers of english use just 7, 500 words in speech and writing. these words appear in red, and are graded with stars. one - star words are frequent, two - star words are more frequent, and three - star words are the most frequent. the thesaurus of synonyms and related words is fully integrated into the dictionary entries. click on the t button in an entry to review the synonyms and related words for that meaning. more mike lost his job last year. register now and don ' t lose your right to vote. the family lost everything when their home burned down. an unreasonably high exchange rate lost them export markets. they feared losing the sale to a rival company. ' how did you do in the quiz? ' ' we lost. ' england lost 2 – 1 to germany. they lost by only one point. those comments may well have lost them the election. the plane lost cabin pressure and everyone had to use oxygen masks. a plan to reduce the amount of working time lost through sickness he must realize that an outstanding opportunity has been lost. there ' s no time to lose ( = used for saying that it is necessary to do something as quickly as possible because the situation is urgent ). this is the british english definition of lose. view american english definition of lose. a part of an atom that moves around the nucleus ( = centre ) and has a negative electrical charge a must for anyone with an interest in the changing face of language. the macmillan dictionary blog explores english as it is spoken around the world today. global english and language change from our blog


the dominant language as well. so often, the cultural wealth that exists in a culture exists through the language itself. if that ' s gone, the cultural continuity is gone. so, we hope we see as many cultures preserved as well as languages. you can find out more about the project at endangeredlanguages. com. twitter has deleted the account of someone posing as the actor bill murray. now, no one should ever pretend to be bill murray. here with me to discuss that, is - - i can ' t believe we got him - - bill murray. bill murray ( from a promotional video for " moonrise kingdom " ) : hello, i ’ m bill murray. moe : bill, someone got on twitter using the name bill _ murray and proceeded to rack up tens of thousands of followers. then he stole tweets from other people, and passed off the jokes as his own. what did this guy do to your reputation? murray ( from " ghostbusters " ) : he slimed me. moe : yeah, i think so. really got a lot of people upset on twitter too. murray ( from " ghostbusters " ) : human sacrifice, dogs and cats living together, mass hysteria. moe : i don ' t know if it went that far. fake bill on twitter did start asking people for money and people sent it to him or them. murray ( from " rushmore " ) : just remember, they can buy anything but they can ' t buy backbone. don ' t let them forget that. moe : anyway, he ' s been removed and your reputation will be fine. murray ( from " caddyshack " ) : so i got that going for me, which is nice. moe : it is nice.


myoclonus refers to quick, lightning - like jerks ( contractions ) of a muscle or a group of muscles. myoclonus may involve only one hand, a group of muscles in the upper arm or leg, or a group of facial muscles. or it may involve many muscles at the same time. hiccups are a type of myoclonus that involves only the diaphragm, the muscle that separates the chest from the abdomen. myoclonus may occur normally, often when a person is falling asleep. or it may result from a disorder, such as the following : myoclonus can occur after a person takes high doses of certain drugs such as antihistamines, some antidepressants ( such as amitriptyline ), bismuth, levodopa, or opioids ( narcotics ). myoclonus can be mild or severe. muscles may jerk quickly or slowly, rhythmically or not. myoclonus may occur once in a while or frequently. it may occur spontaneously or be triggered by a stimulus, such as a sudden noise, light, or a movement. for example, reaching for an object or taking step may trigger jerks that disrupt the movement. in creutzfeldt - jacob disease ( a rare degenerative brain disorder — see see prion diseases : creutzfeldt - jakob disease ( cjd ) ), myoclonus becomes more obvious when people are suddenly startled. if myoclonus is due to a metabolic disorder, it may persist and affect muscles throughout the body, sometimes leading to seizures. diagnosis and treatment the diagnosis is based on symptoms. other tests may be done to identify the cause. the cause is corrected if possible. for example, drugs that can cause myoclonus are stopped. a high or low blood sugar level is corrected, and kidney failure is treated with hemodialysis. if the cause cannot be corrected, valproate or levetiracetam ( anticonvulsants — see seizure disorders : drugs used to treat seizures. ) or clonazepam ( a mild sedative ) sometimes helps. when given with carbidopa, the dietary supplement 5 - hydroxytryptophan ( which is produced by the brain ) may also help. last full review / revision august 2007 by david eidelberg, md ; michael pourfar, md


receptive and expressive language all communication has two aspects : receptive language and expressive language. receptive language is what we hear and understand. expressive language is what we say to others. i believe that empathy is also a form of communication ; one that is as essential to each of us as is spoken, written, or signed language in understanding the feelings of other sentient beings and in conveying our reaction to them. to oversimplify, one might think of language as the cognitive component of communication, whereas empathy is the emotional component. of course, in reality, they overlap and complement each other. receptive empathy is the ability to perceive the feelings that others are experiencing. expressive empathy is the ability to convey that understanding to others. definition of empathy “ empathy ” is a complicated word — it means so many different things to different people. and, a discussion of whether autistic people have a capacity for empathy that is different from most other people further complicates the conversation. a web search on the single word “ empathy ” produced for me these top 5 results, defining the word in 5 different ways : - empathy is the capacity to recognize emotions that are being experienced by another sentient or fictional being. ( wikipedia ) - the imaginative projection of a subjective state into an object so that the object appears to be infused with it ( mirriam - webster ) - the intellectual identification with or vicarious experiencing of the feelings, thoughts, or attitudes of another ( dictionary. com ) - empathy is the experience of understanding another person ’ s condition from their perspective. ( psychology today ) - identification with and understanding of another ’ s situation, feelings, and motives. see synonyms at pity. ( thefreedictionary. com ) so, which is it? “ recognize emotions ” or “ imaginative projection ” or “ intellectual identification ” or “ vicarious experience of understanding perspective ” or “ identification and understanding ” or “ pity ”? it is probably all of those things and more, including sympathy and compassion. trying to understand what people intend to convey by using the word is a bit like justice potter ’ s infamous definition of pornography. empathy is something you know when you experience it, even though it is hard to describe in words. are there “ types ” of empathy? modifying the word “ empathy ” with “ cognitive ” and “ affective ” represents an ill - advised attempt to deconstruct empathy, in my view. much has been made of the idea that these two aspects of empathy ( to the extent that this dichotom


empathy ” with “ cognitive ” and “ affective ” represents an ill - advised attempt to deconstruct empathy, in my view. much has been made of the idea that these two aspects of empathy ( to the extent that this dichotomy has any validity at all, which i doubt ) arise from different parts of the brain, and that one or the other is deficient in certain personality types. this kind of hair - splitting is a distraction, it seems to me, when it comes to understanding the role and functioning of empathy. i ’ m sure there is a wide range of empathic capacity, both in terms of experiencing empathy ( whatever it is ) and in expressing it. those with alexithymia may have empathic capacity but may not recognize what they are experiencing or be able to express it. and all of my discussion here so far has nothing directly to do with autism. empathy is a universal human trait. and beyond. clearly, many other animals have empathic capacity as well. empathy arises from, or at least is related to, mirror neurons. in the famous incident of the discovery of mirror neurons, a monkey watched an object being picked up, and his brain region for picking things up fired as if he were doing it himself. so, he experienced what it was like to pick up an apple ( or whatever it was ), but not from the perspective of the other monkey ( he ’ s not inside that brain ) but from the perspective of how he would feel if he were doing what he was observing. and what does all of this have to do with autism? now comes the tricky part with respect to autism. it ’ s twofold. the descriptions that follow are experiential ( my own experiences and those of other autistic people i ’ ve spoken with ), and represent my own speculations. what i report here may or may not be generalizable to other autistic people. see the link in the previous paragraph for a discussion of some of the controversy surrounding the linkage ( if any ) between autism and mirror neurons. autism and receptive empathy it may be ( 1 ) that the mirror neuron system in the autistic brain is impaired because of the usual sensory overload that is always going on. it ’ s not that the mirror neurons are defective, it ’ s just that their functioning is clouded by the brain having so much else to deal with at the same time. distractions, if you will. so the autistic person will not have the


s not that the mirror neurons are defective, it ’ s just that their functioning is clouded by the brain having so much else to deal with at the same time. distractions, if you will. so the autistic person will not have the receptive clarity that matches the neurotypical — what is being called by some “ cognitive empathy. ” the emotional state of another being is recorded, but not processed with the same clarity because of the other demands on attention. the tms experiments i participated in at beth israel demonstrated this. the experiment involved suppressing activity in a small area in the right hemisphere of my brain. neuroscientists know that, through a process called neuroplasticity, when one area of the brain is compromised, another area will attempt to take over the lost functionality. that often involves the equivalent region in the opposite hemisphere of the brain. broca ’ s area is heavily involved in language and ( therefore ) social cognition, and much more. it is a complex and important region of the brain that is somewhat imprecisely located in the part of the brain known as brodmann ’ s areas 44 and 45. i say “ it ” although, in my understanding ( i have no formal training in neuroscience ), there are two equivalent areas, one in each hemisphere, and the lion ’ s share of language processing occurs in the dominant hemisphere ( the left one for right - handed people like me ). broca ’ s area, besides its central role in language comprehension and creation, also seems to serve as a bridge between the prefrontal cortex ( cognition ), and regions that control motor and somatosensory ( tactile and other sensory ) systems of the body. it is also thought to be rich in mirror neurons. for all of these reasons, the scientists in the tms lab hypothesized that by temporarily and artificially suppressing the right side of my brain in the area just described, the left hemisphere would be more strongly activated than usual, thereby improving language and social ( empathic ) cognition. how right ( so to speak ) they were! i experienced ( both subjectively and in their computerized measurements ) sharpened ability to interpret emotional content more accurately. the difference in clarity was astounding to me and to others i spoke with who were subjects in the experiment. caitlin, for example, was shocked to find that she could see emotional content in written sentences and in video clips which, with the benefit of hindsight, she had not been able


me and to others i spoke with who were subjects in the experiment. caitlin, for example, was shocked to find that she could see emotional content in written sentences and in video clips which, with the benefit of hindsight, she had not been able to see before. my clarity was more intellectual. i was able to solve ( computerized ) tasks faster than the computer could feed them to me, whereas before i had struggled and was unsure of the answers. subjectively, it was like night and day, although i ’ m sure that the difference in my performance was measured in milliseconds. the difference in what caitlin and i experienced ( and john had a musical revelation, among many other experiences ) was probably a function of where we started. i was relatively better ( compared with her ) at emotional reception. she, for example, had once been floored to find out that her brother knew more ( much more ) about the personal life of her receptionist than she did, although he lived in a distant city. it was just that when he called to speak with caitlin, he would chat with the person who answered the phone about vacation plans and the like. it never occurred to caitlin to make that kind of emotional connection. the irrelevancy of “ cognitive ” versus “ affective ” empathy which brings me around to the other bit ( 2 ) about autism and empathy. take the psychology today definition : “ empathy is the experience of understanding another person ’ s condition from their perspective. ” please. think of the monkey. picking up a banana is probably a pretty universal monkey experience, so it ’ s easy to imagine that the mirror neurons of monkeys allow them to experience watching another monkey and essentially experience ( vicariously ) a nearly identical experience. now, take an autistic brain. not mine, please. i need it. if i watch a neurotypical pick up a banana, i am likely to be less clear about how that feels to them because they experience the world in a way that is very different from mine. i ’ m being metaphorical here, in case you didn ’ t pick up on that ( so to speak ). a physical action is one thing, but a more complex emotional reaction is quite a different level of experience. how can i empathize what you are going through if your way of experiencing the world is vastly different from mine? this works both ways, of course. how can a neurotypical person empathize with me if they have no clue what my brain is experiencing? so,


you are going through if your way of experiencing the world is vastly different from mine? this works both ways, of course. how can a neurotypical person empathize with me if they have no clue what my brain is experiencing? so, it ’ s not a lack of empathy, or a lack of empathic capacity, it ’ s a knowledge or experiential gap. i can tell when my horse is happy to see me, or when he is in a playful mood, or frightened ; these are fairly universal emotions. but my empathy doesn ’ t go too deep because i don ’ t really know what it ’ s like to be a horse. or, maybe at some fundamental level, i do. i don ’ t always grok why he ’ s upset, but i know when he is. now, all of that is about receptive empathy ; taking in and appreciating the emotional state of another being. this may be what is meant by “ cognitive ” empathy. but i also think receptive empathy includes components ( or maybe all ) of what has been termed “ affective empathy ” or “ pity ” or “ compassion ” — not just understanding, but sharing the emotional state of another. i believe this must naturally flow via the mirror neuron system that enables us to take in the feelings of another. if one is truly understanding what another is experiencing, it naturally follows that one is experiencing their emotions, too. from an evolutionary point of view, the value of being able to understand how someone else is feeling is being able to predict their behavior. if someone picks up a banana and smiles, that ’ s pretty non - threatening, but if someone picks up a rock and scowls, it might be better to take protective action. to truly take in another ’ s emotions, in the process i ’ m calling receptive empathy, one must also experience an approximation of those emotions. although i ’ m aware these emotions are yours, and not mine, i experience my version of your anger, your pain, and your joy. it can ’ t be any other way. and yes, there are people who have difficulty comprehending what they are experiencing emotionally, and conveying it, too. but, as alluded to earlier, that is a condition called alexithymia, not autism. although studies about this are scant, i ’ m not aware of any definitive study that shows that alexithymia is more prevalent in the neuroexceptional population than it is in the neuro


alexithymia, not autism. although studies about this are scant, i ’ m not aware of any definitive study that shows that alexithymia is more prevalent in the neuroexceptional population than it is in the neurotypical one. in my work with neuroexceptional couples ( in a support group setting ), i observe a fairly high proportion of alexithymia among the partners who are not neurotypical, but my sample is a highly self - selected subgroup of all neuroexceptional people, and i don ’ t have a control group to compare with. for me, when i experience high receptive empathy ( which includes sympathy, compassion or pity ), such an experience is likely to lead to an emotional state of shock that requires me to tone down my feelings, because the nerves are too raw and exposed. so, i withdraw, i put up barriers to keep the world out, to keep things from getting worse. i can only take so much. most autistic people with whom i have talked about this agree. we have too much empathic capacity. it is paralyzing. why is that? i ’ m not sure. excess myelination? i ’ ll get back to you on that. autism and expressive empathy : the challenge for autistic people the biggest complaint in my couples support groups is that the ( typically ) asperger ’ s partner does not express empathy. i explain the bit that i ’ ve just gone through, that those of us who are autistic experience a high degree of understanding ( what i have called here receptive empathy ), and that our flat affect or silence does not mean we lack comprehension or sympathy. it ’ s just that dealing with these raw emotions is too frightening. thus, we exhibit a lack of what i have come to call expressive empathy. to partners who are feeling emotionally isolated, and are in need of validation, it ’ s not comforting to hear this. to them, there is no empathy if it isn ’ t expressed. and they have a good point. we autistics often stop one step short of what empathy is all about ; connecting with another human being, to validate and comfort them. without that piece, it does not serve its purpose. the result is, from the outside observers point of view, a “ lack ” of empathy. no reaction. or an “ inappropriate ” ( oh, how i hate that word ) reaction. if fact, the reaction is an internal volcano that is


. the result is, from the outside observers point of view, a “ lack ” of empathy. no reaction. or an “ inappropriate ” ( oh, how i hate that word ) reaction. if fact, the reaction is an internal volcano that is about to erupt. sometimes it does, and that is one form of meltdown. sometimes it is contained, and the world is shut out. i remember a time in my second marriage when things were not going well, and i was talking with my shrink about it. at one point, he said to me ( in frustration ), “ can ’ t you just tell her you love her? that ’ s what she wants to hear! ” and, i realized ( for complex reasons ) that, no, i was not capable of that at that time. it seemed like lying to me. yet, it would have been a harmless lie that could have made all the difference to her. i was empathizing with her distress, but i was not able to communicate that to her in a way that would have been helpful. the terms i have used here, receptive and expressive, are often used to describe forms of language communication, which is where i started this post. and that ’ s really what empathy is, in its fullest expression ; communicating emotional states. autistics are really good at receptive empathy, but some of us fall short when it comes to using expressive empathy. this is a failure of execution, not of cognition. our brains work just fine, thank you. we just need to learn how to let other people know that. the good news is called neuroplasticity, and there is a way to use that, in neurally - inspired therapies and techniques that can change our patterns of behavior. stay tuned. much more to come on those subjects. meanwhile, i will be practicing my expressive empathy.


this mathematically oriented introduction to the theory of logic programming presents a systematic exposition of the resolution method for propositional, first - order, and horn - clause logics, together with an analysis of the semantic aspects of the method. it is through the inference rule of resolution that both proofs and computations can be manipulated on computers, and this book contains elegant versions and proofs of the fundamental theorems and lemmas in the proof theory of logic programming. advanced topics such as recursive complexity and negation as failure and its semantics are covered, and streamlined setups for sld - and sldnf - resolution are described. no other book treats this material in such detail and with such sophistication. doets provides a novel approach to resolution that is applied to the first - order case and the case of ( positive ) logic programs. in contrast to the usual approach, the concept of a resolvent is defined nonconstructively, without recourse to the concept of unification, allowing the soundness and completeness proofs to be carried out in a more economic way. other new material includes computability results dealing with analytical hierarchy, results on infinite derivations and an exposition on general logic programs using 3 - valued logic.


a depressive disorder is a whole - body illness, involving the body, mood, and thoughts, and affects the way a person eats and sleeps, feels about himself or herself, and thinks about things. it is not the same as being unhappy or in a blue mood. nor is it a sign of personal weakness or a condition that can be willed or wished away. people with a depressive illness cannot merely " pull themselves together " and get better. without treatment, symptoms can last for weeks, months, or years. appropriate treatment, however, can help most people who suffer from depression. during any one year period, nearly 19 million american adults suffer from depressive illness. yet, treatment can alleviate symptoms in nearly 80 percent of cases. women experience depression about twice as often as men. many hormonal factors may contribute to the increased rate of depression in women - - particularly such factors as menstrual cycle changes, premenstrual syndrome ( pms ), pregnancy, miscarriage, postpartum period, perimenopause, and menopause. many women also face additional stresses such as responsibilities both at work and home, single parenthood, and caring for children and aging parents. many women are also particularly vulnerable after the birth of a baby. the hormonal and physical changes, as well as the added responsibility of a new life, can be factors that lead to postpartum depression in some women. while transient " blues " are common in new mothers, a full - blown depressive episode is not a normal occurrence and requires active intervention. treatment by a sympathetic health care provider and the family ' s emotional support for the new mother are prime considerations in aiding her to recover her physical and mental well - being and her ability to care for and enjoy the infant. depressive disorders come in different forms, as do other illnesses, such as heart disease. three of the most prevalent types of depressive disorders include the following : - major depression. a combination of symptoms ( see symptom list ) that interfere with the ability to work, sleep, eat, and enjoy once pleasurable activities. these disabling episodes of depression can occur once, twice, or several times in a lifetime. - dysthymia. long - term, chronic symptoms that do not disable, but keep people from functioning at " full steam " or from feeling good. sometimes, people with dysthymia also experience major depressive episodes. - bipolar disorder ( manic - depression ). a chronic, recurring condition


do not disable, but keep people from functioning at " full steam " or from feeling good. sometimes, people with dysthymia also experience major depressive episodes. - bipolar disorder ( manic - depression ). a chronic, recurring condition that includes cycles of depression and elation or mania. within these types, there are variations in the number of symptoms, their severity, and persistence. the following are the most common symptoms of depression. however, each individual may experience symptoms differently. in general, nearly everyone suffering from depression has ongoing feelings of sadness, and may feel helpless, hopeless, and irritable. the american psychiatric association suggests that professional help is advisable for those who have four or more of the following symptoms continually for more than two weeks : - noticeable change of appetite, with either significant weight loss not attributable to dieting or weight gain - noticeable change in sleeping patterns, such as fitful sleep, inability to sleep, early morning awakening, or sleeping too much - loss of interest and pleasure in activities formerly enjoyed - persistent sad, anxious, or " empty " mood - feelings of hopelessness, pessimism - restlessness, irritability - decreased energy, fatigue, being " slowed down " - feelings of worthlessness - persistent feelings of hopelessness - feelings of inappropriate guilt - inability to concentrate or think, indecisiveness - recurring thoughts of death or suicide, wishing to die, or attempting suicide ( note : individuals with this symptom should receive treatment immediately! ) - melancholia ( defined as overwhelming feelings of sadness and grief ), accompanied by the following : - waking at least two hours earlier than normal in the morning - feeling more depressed in the morning - moving significantly more slowly - disturbed thinking - - for example, severely depressed people sometimes have beliefs not based in reality about physical disease, sinfulness, or poverty - physical symptoms, such as headaches, digestive disorders, and chronic pain specific treatment for depression will be determined by your health care provider based on : - your age, overall health, and medical history - extent of the depression - your tolerance for specific medications, procedures, or therapies - expectations for the course of the disorder - your opinion or preference generally, based on the outcome of evaluations, depressive disorders are treated with medication or either psychotherapy or cognitive behavioral therapy, or a combination of medication and therapy. you can also help yourself. depressive disorders can make a person feel exhausted, worthless, helpless, and hopeless. such negative thoughts


zoologger is our weekly column highlighting extraordinary animals – and occasionally other organisms – from around the world step from a sunlit hillside into the darkness of a cave, and you immediately have a problem : you can ' t see. it ' s best to stand still for a few minutes until your eyes adjust to the dimness, otherwise you might blunder into a hibernating bear that doesn ' t appreciate your presence. the same thing will happen when you leave again : the brightness of the sun will dazzle you at first. that ' s because your eyes have two types of receptor : one set works in bright light and the other in dim light. barring a few minutes around sunset, only one set of receptors is ever working at any given time. peters ' elephantnose fish has no such limitations. its peculiar eyes allow it to use the two types of receptor at the same time. that could help it to spot predators as they approach through the murky water it calls home. peters ' elephantnose fish belongs to a large family called the elephantfish, all of which live in africa. they get their name from the trunk - like protrusions on the front of their heads. but whereas the trunks of elephants are extensions of their noses, the trunks of elephantfish are extensions of their mouths. to find a peters ' elephantnose fish, you must lurk in muddy, slow - moving water. look closely, because the fish is brown and so is the background. it finds its way through the murk using its trunk, which generates a weak electrical field that helps it sense its surroundings and even discriminate between different objects. the fish ' s electric sense allows it to hunt insect larvae in pitch darkness. the fish has paid a price for its electrical sensitivity. processing the signals takes brainpower, so it has an exceptionally large brain. as a result, 60 per cent of the oxygen taken in by the fish goes to its brain. even humans, with our whopping brains, only devote 20 per cent of our oxygen to them. now for its eyes. most vertebrates, including humans, have two types of light receptors on their retinas : rods and cones. rods can sense dim light, but become bleached in bright light and stop working. cones can ' t see in dim light, but given enough light they can see fine details and colours. most animals ' eyes are specialised for one or the other. animals that are active during the day tend to have more cones than nocturnal animals


##enbach thinks its oddball visual system isn ' t a mistake. " it ' s the right type for this fish, " he says. journal reference : science, doi : 10. 1126 / science. 1218072 if you would like to reuse any content from new scientist, either in print or online, please contact the syndication department first for permission. new scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to. have your say only subscribers may leave comments on this article. please log in. only personal subscribers may leave comments on this article thu jun 28 22 : 15 : 54 bst 2012 by freederick if i understand correctly, each cup - shaped depression serves as a single aggregate receptor, combining the output of all the individual light - sensitive cells comprising it. in effect, the fish is trading resolution for sensitivity. this is the same sort of effect as used to be employed in high - iso photographic film, where the larger, flattened grains of photosensitive chemicals resulted in high sensitivity, at the cost of a coarse - grained image. the fish employs an even more effective method, effectively combining many smaller " grains " into one huge hypersensitive receptor. all comments should respect the new scientist house rules. if you think a particular comment breaks these rules then please use the " report " link in that comment to report it to us. if you are having a technical problem posting a comment, please contact technical support.


keynote address : research agenda and policy perspectives on agriculture for development the keynote address of the conference, by justin lin, the chief economist at the world bank, focuses on future research priorities and the process of implementing the policy objectives of the 2008 world development report, " agriculture for development. " justin lin is the chief economist of the world bank. this lesson plan should be used for grades 5 - 7 to help practice, learn, and implement the scientific method, using a self - directed study. try dutch! : dutch language taster interested in dutch? curious how dutch sounds? wondering how difficult or easy it is? perhaps you are thinking of studying dutch? then here is your opportunity to have a go at the language yourself and experience what it is like to learn dutch from scratch. you can work through the pack all by yourself. no knowledge of dutch is required. ucl grant museum of zoology eutherians image collection this is a set of images taken from a teaching resource created at university college london, in collaboration with their museum of zoology. they are primarily along the themes of phylogeny ( evolutionary history ) and functional anatomy. the images are hosted in the uk centre for bioscience ' s imagebank. from ideas to intellectual property ( materials ) this zipped file contains all of the materials that made up the " how to extract value from intellectual property pt 1 ". inside the file is a narrative, the full powerpoint slide and cc licence information for all the clip art and materials that have been used. there are audio files that also can be used under the creative commons. the relevant attribution and sources for the materials can be found in the. ppt of the lecture. nuclear and particle physics a third year course in nuclear and particle physics. could do with a few lhc updates. contains lecture notes, examples,... as well as the files used to create these resources. also has some movies of nuclear collective motion. discusses : 1 introduction 2 a history of particle physics 3 experimental tools 4 nuclear masses 5 nuclear models 6 some basic concepts of theoretical particle physics 7 the fundamental forces 8 symmetries and particle physics 9 symmetries of the theory of strong humbox : keywords / tags matches " oerprs " humbox : keywords / tags matches " oerprs " feed 1 introduction to microeconomics this is a module framework. it can be viewed online or downloaded as a zip file. as taught semester 1 2009 / 2010. there are no pre - requisites to taking


matches " oerprs " feed 1 introduction to microeconomics this is a module framework. it can be viewed online or downloaded as a zip file. as taught semester 1 2009 / 2010. there are no pre - requisites to taking this module and in particular there is no assumption of any prior knowledge of economics. for those who have taken a - level economics or any other version of economics some of the module content will appear familiar to you. however, the methods of analysis and the approach to teaching will quite probably be very different to anything experienced be hathitrust digital library homeopathy the meanings of timbuktu lolita with imraan coovadia the wager lost by winning : on the ' triumph ' of the just war tradition duke on demand highlights for the week of november 7, 2010 ck - 12 biology ( ca textbook ) private universe project in mathematics : workshop 5. building on useful ideas ' til the last drop : johns hopkins addresses the global water challenge education 320 : teaching pe & health, elementary education - group presentations cont. learn about us president theodore roosevelt 1858 - 1919 this volume authored by leading international scholars begin s to sketch the meaning of timbuktu within the context of the intellectual history of west africa in particular and of the african continent in general the book covers four broad areas part i provides an introduction to the region outlines what archaeology can tell us of its history examines the paper and various calligraphic styles used in the manuscripts and explains how ancient institutions of scholarship functioned part ii begins t acclaimed novelist imraan coovadia spoke at uct gordon institute for performing and creative arts gipca great texts big questions public lecture on thursday 1 april he discussed how to read lolita. written by vladimir nabokov lolita was first published in paris in 1955 it is one of the best known and most controversial books of 20th century literature coovadia says i will be talking about the lolita problem how do we respond to a book which is a first person narrative by a man who is trying to s lecture delivered on the 19th of october 2010, part of the elac / ccw seminar series on war and armed conflict. delivered by professor nicholas rengger ( st andrews ). introduced by jennifer welsh this week in duke on demand, during a session in duke ' s baldwin auditorium, duke alumnus yizheng he gets a " master class " lesson from concert pianist and visiting artist awadagin pratt. professor misha angrist discusses the science behind - - and experience of - -


during a session in duke ' s baldwin auditorium, duke alumnus yizheng he gets a " master class " lesson from concert pianist and visiting artist awadagin pratt. professor misha angrist discusses the science behind - - and experience of - - having his entire genome sequenced. a conversation at duke ' s john hope franklin center on the local food movement in durham. and, an " office hours " webcast conversation on prison and african - american literature. as a teacher, have you ever felt that your textbook was not thorough or up - to - date? do you have to use other resources, such as on - line resources, to teach your lessons? as a student, do you believe you can get current information from sources such as the internet rather than your textbook? the answer to these questions is usually a resounding yes. so what do school districts do? they spend millions of dollars every year to buy “ current, ” “ up - to - date ” textbooks. ck12 believes we can do one of the strands of the rutgers long - term study was to find out how useful ideas spread through a community of learners and evolve over time. here, the focus is on the teachers role in fostering thoughtful mathematics., englewoodfourth grade : towers fourth - grade teacher blanche young attempts the towers activity for the first time with her students. she feels that their work is valuable, but questions how much time these open - ended activities are taking away from the standard curriculum. johns hopkins university scientists and policy makers evaluate key factors contributing to the global water issue. class session 7, recorded november 5, 2010. note : class session 6 was not recorded. president theodore roosevelt biography. this is a very short video that gives some data about his assuming of the presidency. the meanings of timbuktu lolita with imraan coovadia the wager lost by winning : on the ' triumph ' of the just war tradition duke on demand highlights for the week of november 7, 2010 ck - 12 biology ( ca textbook ) private universe project in mathematics : workshop 5. building on useful ideas ' til the last drop : johns hopkins addresses the global water challenge education 320 : teaching pe & health, elementary education - group presentations cont. learn about us president theodore roosevelt 1858 - 1919


there is no red line, then either tides online does not have data for that station, or there has been a communications break down. in this case, the graph computes an anomaly based on what data it has, or sets it to 0. then it predicts the total water level for all hours, or after the last of any observations it does have. the next thing of interest is the blue tide line. this is the astronomical tide at every hour. the harmonic constants used were obtained from http : / / www. co - ops. nos. noaa. gov / data _ res. html. we then note the gold storm surge curve, which is created by " pasting " one 48 hour prediction to the next 48 hour prediction. that is, using 12 hours from each prediction until the last prediction where we use 48 hours. the result is that we may generate kinks in the curve every 12 hours, where the model adjusted its prediction based on new data from the gfs wind model. next we note the green curve, which is the " anomaly " referred to above. this is simply the observation - ( tide + storm surge ). preferably it is constant. the amount of deviation from a constant is an approximation of our error. since we add the 5 day average of this value to our prediction, the perfect forecast does not have to have a zero anomaly. finally we see the black forecast curve. this is what we are really interested in, which is the total water level created by adding the 5 day average anomaly to the predicted tide, and the predicted storm surge. the history button allows one to see how the model has done over the last day or so. it displays 3 graphs. the first one is the current graph based on the current model run, and the current observations. the second graph is the last graph generated using the last model run. the third graph is the last graph generated using the next to last model run. this gives a view of the model over the last 24 to 36 hours depending on when the current time is. to print this page out ( netscape instructions ) it is recommended that you right click on the history frame and choose " open frame in new window ". then choose page setup, and set the top and bottom margins to 0. then choose print, and preferably send it to a color printer, ( although a black and white does work ). the result should be 3 graphs on the same page. we would like to thank the following people / organizations :


ear, the political context was inspired by the gran chaco war, a bloody conflict - resulting in 100, 000 deaths - between bolivia and paraguay, which began in 1932, 2 then in tintin and the picaros, herge illustrated the economic and political situation in south america. syldavia and borduria are the most successful of herge ’ s imaginary countries. these “ east european metaphors ” recall two critical periods of the twentieth century. 3 the two countries first appeared in king ottokar ’ s sceptre, in 1938. since 1933, germany had threatened austria, and on march 11, 1938, german troops had invaded the little country. these events were recent when the serialization of king ottokar ’ s sceptre began. in fact, syldavia is the synthesis of three real countries. first, the conspiracy and the “ fifth column ” infiltrated into syldavia represent the conspiracy against austria. second, its old conflict with borduria, its architecture and its language have polish characteristics. and third, geography and history resemble these of romania. likewise, borduria is similar to germany. for example, they both invaded their neighbour, syldavia and poland on several occasions. moreover, the name of the pro - bordurian party ’ s leader, “ musstler ”, seems to be a synthesis of mussolini and hitler. 4 uniforms that look like ss uniforms, and planes that are very similar to messerschmit 109e fighters, 5 are other signs of herge ’ s aim : to describe and denounce an anschluss. sixteen years later, syldavia and borduria were back in the calculus affair ( 1954 - 1956 ) during the cold war. in europe, the situation had been very tense since 1946, a situation worsened by the berlin blockade, the korean war and the warsaw pact. the arms race speeded up and the first h - bomb was exploded in 1953. spying was intense. in the calculus affair, many elements refer to the events of the period. tensions between the two countries appear to have been inspired by the situation between the two germanys. moreover, the personality cult of plekszy - gladz, the bordurian president, resembled stalin ’ s personality cult. 6 finally, with its architecture and the methods of its police, borduria is similar to a country of the eastern bloc. syldavia and borduria could easily represent the confrontation between the two blocs, as they represented in the


. 6 finally, with its architecture and the methods of its police, borduria is similar to a country of the eastern bloc. syldavia and borduria could easily represent the confrontation between the two blocs, as they represented in the past the conflict between western democracies and germany. 7 through imaginary countries, like syldavia and san theodoros, and direct allusion to real events, herge showed a concern for accurate explanations that had consequences in the perception of tintin stories. many adults read tintin a long time after they discover his adventures, maybe because they did not completely understand the historical context during their childhood. but some questions about the perception of tintin stories still exist. how would a child who does not know anything about history interpret the context of king ottokar ’ s sceptre, for example? how would a young japanese interpret the political situation in the blue lotus? nevertheless, enormous sales of tintin ’ s stories - more than 120 million copies in 40 languages8 - show that allusions to historical events do not affect the success. events were seen through belgian eyes, but the hero travels the whole world and he is extremely open - minded. nationality, language and religion have little significance, because a reader of tintin ’ s adventures can always identify with the reporter. herge said “ there are clearly reasons for this success since it has lasted so long and continues to grow. well then? … it ’ s like a flowing stream, but what is its nature? … i receive, for example, a lot of mail from india. here in the office are two letters from calcutta. now, what can there be in common between a boy in calcutta and myself? … that ’ s something i am still asking myself without finding an answer. ” 9 his allusions to historical events may be one of the explanations.


fetuses, infants, and toddlers, as well as older children and teens are particularly susceptible to environmental insults due to their rapid rate of growth, development and reproduction of cells. this vulnerability makes children a specific focus of environmental health research on the effects of lead, chemical dump sites, pesticides, pcbs, benzene, environmental estrogens, and outdoor and indoor air contaminants. scientists want to know which substances pose significant health risks, how to identify susceptible children, and how to intervene to prevent illness. the following are some of the studies conducted or financed by the national institute of environmental health sciences, one of the national institutes of health, which focus on children : lead ( commonly found in old paint, household dust, soil, pipe solder and some ceramics ) has long been known to cause severe health problems at high doses, including muscle and abdominal pain, mental impairment, paralysis, and even death. recent studies supported by the niehs suggest that a young person ' s lead exposure is linked not only to lower iqs and lower high school graduation rates but to increased delinquency. preliminary data from two other grantees ' studies indicate that young girls exposed to lead store the metal in their bones. this lead can be released when they become pregnant years later, exposing their fetuses. until recently, however, we have not appreciated the devastating effect of low exposures early in life. basic research financed by the niehs has shown the adverse effects of lead on children ' s iq and physical development at levels previously considered safe. based on these and other findings, public health officials declared lead the number one environmental hazard to american children and the federal centers for disease control and prevention lowered the acceptable blood lead level. research by the niehs grantees has helped identify sources of lead in the environment, design public health prevention efforts, and develop treatment to remove lead from exposed children, a process called chelation. to help improve treatments, the niehs supported the study of dimercaptosuccinic acid ( dmsa ) as a chelating agent. known generically as succimer and the trade - name chemet, dmsa binds with the lead, hastening its removal from the body and can be administered orally without hospitalization, an improvement over previous intravenous therapies. succimer is approved by the food and drug administration to treat lead levels that exceed 45 micrograms per deciliter of blood. however, adverse effects of lead are evident at levels


an effective slogan. to find the lowest common denominator was a mission, not a mistake. if a rival radical group coined a catchy phrase, the bolshevik took the highroad of their revolutionary creed - highway robbery. steal it and spread it, make it the bolshevik ' s own operated as the operative unprincipled principle. the end justified the means. the bolshevik banners read simply : bread, peace & land. all power to the soviets. as they rode waves of radical spirit and popular support, notably in petrograd, lenin pushed for bolder action. impatient, unwilling to wait out the polite democratic discussion he marshaled his words to put nerve and backbone into the bolsheviks leadership. lenin wanted determined, violent action to seize power. he avowed himself a scientific socialist. yet at crunch time he felt the moment. succinct when it counted he explained, " the government is tottering. we must deal it the deathblow at any cost. to delay action is the same as death. " the means of communication - the telegraph office, the telephone exchange, and the radio gear on the cruiser aurora, the telephones at the winter palace - were ordered seized as a priority. the military - revolutionary committee moved swiftly to take over printing plants, too. to hold the means of communication denied them to enemies. public opinion mattered ; making sure rivals could not get their message out mattered more. the only fairness doctrine was the bolsheviks retaining state power. the bolsheviks understood the power of the mass media. their problem would not be the media, but the masses. communism, whose by - word was " workers of the world unite! ", surprised itself by coming to power in a backward, peasant - dominated country. the scientific plan of karl marx and its endless elucidation by marxists envisioned the proletariat taking power in an advanced capitalist country. even its workers had the stench of peasant mud on their boots. ties to village life, the village way to find a wife, and not so sober vices remained strong. soldiers who went bolshevik at the front to get away from the frozen hell that was wwi largely were just peasants in uniform. those who did not vote with their feet against the status quo ( fleeing home as soon as discipline broke down ) soon wanted to leave their red leaders for the joys of raiding manor houses near their native village, too. 1917 was, the bolsheviks soon realized just an incredible year ; in the heat of revolution they forged amazing partnership with workers, with peasants


kiss - keep it simple stupid. they believed most ordinary russians thought in images. exposure to european culture forced them to recognize that russian lives were drab. communist visionaries were willing to experiment with bold artists. graphic masters of new kinds of art embraced the liberation revolution brought. art enlisted in the cause. brightly colored propaganda trains carried the city based idea that " the times they were achangin ' " across the land. stark contrasts served the bolsheviks well. new = good ; old = bad. reds meant progress - most anything else equaled a return to a hellish existence. in the civil war that quickly followed lenin ' s rise to power, the bolsheviks did reach the masses. the idea of the fighters for human justice and equality, the bolsheviks, were battling against all odds, against all the world ' s armies that had come to destroy them received widespread attention. the theme of the new kind of socialist life form doing anything it could to survive in a hostile encirclement of enemies was created during the civil war. this theme would be revived periodically as a leitmotif. to survive a civil war the bolsheviks acted ruthlessly. again, the end justified the mean. equally important, their enemies, former tsarist admirals, generals, counts and liberal politicians ( backed by british, french, american, and japanese troops ) refused to court public opinion with any kind of effective attempt to persuade mass groupings to side with them. white disdain proved fatal. the bolsheviks with the propaganda field to themselves got a message out that opposition armies, the whites, wanted to return the country to the old order. most who would decide, decided to risk the promise of the unknown over a return to the past. ( some of course exhibited total cynicism : a well - know civil war anecdote relates that in a village one peasant shouts : " hurray for the incoming troops. " then a neighbor asks the question " whose side are you on? " he answers : " the ones riding in. " ) the propaganda campaign, plus of course some brilliant military leadership and absolute ruthlessness in dealing with any perceived enemy won the bolsheviks an against all odds victory. the civil war created the idea that bolshevism could do the impossible. it gave rise to a slogan " there is no fortress bolshevism cannot storm ", that embodied a ' can do ' mentality like that of the u. s. marines. also as a formative experience the civil war ( 1918 - 1921 ) provided the seed bed


there is no fortress bolshevism cannot storm ", that embodied a ' can do ' mentality like that of the u. s. marines. also as a formative experience the civil war ( 1918 - 1921 ) provided the seed bed for new images of heroes and all the metaphors of war campaigns, fronts, volunteers, even vanguards issuing commands, dictating what was needed to stave off destruction by the hostile bad guys. the incredible result of the civil war validated for masses of people, the bolshevik ' s political power grab in 1917. moreover, it created a matrix for how propaganda makers shake and shape attitudes. it reinforced the idea, if it needed any reinforcing, that propaganda was a powerful tool for protecting the newborn proletarian state in an aggressively anti - soviet russia world. another trait the propagandists called on was a pre - revolutionary role that the well educated had played with the masses : as teachers, enlightenment - providers. well before marxism marched east, russian radicals had a long established a tradition of " going to the people ", the peasants as volunteer teachers. latter in cities how did believing marxist intellectuals make friends with real workers? factory hands, after all, lived in different parts of town, worked long hours, and enjoyed different habits of life from those whose heads swam with a sea of abstract ideas. before the revolution it was not easy ; the tsar ' s secret police, street police, and factory police kept keen eyes out for agitators, especially those trying to incite the masses. they met first in adult education classes for workers. after the revolution the empowered bolshevik wanted to repeat their role as enlightenment - providers on a grand scale. equally important, propagandists realized that if they wanted to build a new society, one imbued with new myths, new rituals, new icon communists had to do away with the old. to make room for the new they had to tear down the old. sometimes this entailed the most literal meaning of the word : iconoclasm - old icons were torn down. churches lost their bells. to change the very soundscape of moscow ( think of the 1812 overture - the piece of music played on 4th of july and other times when fireworks are displayed - - tchaikovsky wrote it to include the sound of moscow ' s many church bells ) radicals tore down church bells ; later some would try to create a new ' proletarian orchestra ' sound by setting off factory whistles everywhere. the church was a prime target for the


the man who guided " ten days that shook the world " was a cathartic experience. mass mourning created as well as vented extreme emotions. organized ceremonies took place across the land - the first mass mobilization in peacetime of ordinary citizens. by preserving lenin ' s body for veneration soviet science created a sign that it could overcome nature, the decay of death. lenin ' s resting - place became the central showplace, ground zero for the communist movement uniting workers of the world. lenin lived as the man who brought the future into backward russian homes. before he died the revolutionary decided a great symbol for what communism could deliver would be creation of a nationwide electrical system. naturally, the propagandist in him made a slogan out of his techno - idea : " communism = soviet power + electrification of the whole country. " when the soviet union became wired up with light bulbs, called by one his nicknames - " ilych lamps " enlightened and changed millions of peasants ' lives. it was a change and a propaganda coup that won many over as loyalist of a new state, one that drastically changed things. lenin ' s idea transformed lives and became a foundation myth of the scientific regime. parts of a 1924 poem by the blue blouse workers ' theater gloried : we, the workers and the peasants in the hut of the widow natalka electricity and steam teachers of new generations built on the cult of lenin as a tool for shaping the minds to a new soviet way of thinking. indoctrination came in the guise of school age " young pioneer " organizations. pioneers pledged to fulfill his legacy. that legacy proved very malleable. lenin slogans, praise of the proletariat, love for the red socialist - cause were memorized. sugary poems about his pure spirit and dedication to communist revolution go adorned classroom walls, community centers, even the toy stores. lenin ' s ruthless critical approach to thinking quickly passed into the dustbin of history. just as many american school children know just a formula about their founding father george washington ( wooden teeth, could not tell a lie, chopped down a cherry tree, fought the british, maybe owned slaves ) soviet children internalized limited notions of how the ' revolutionary genius " behaved. a lenin code of conduct became the model to be copied. potted histories of the communist party where lenin always played the lead role served as primers for understanding history. lenin associated rituals regulated daily behavior. children pinned on badges depicting an angelic " baby lenin. " boys and girls


model to be copied. potted histories of the communist party where lenin always played the lead role served as primers for understanding history. lenin associated rituals regulated daily behavior. children pinned on badges depicting an angelic " baby lenin. " boys and girls raised their hands above their faces vowing to be " always ready " as lenin had been ( as heroes in the civil war, too had been ) to defend and to extend the revolution. lenin - centric pioneer activities organized children ' s lives. the best emulators of the best lenin earned a summer at the best - equipped, most prestigious summer camps. of course, as a socialist country summer camp, like many things for kids, including medical care was free. still prestige counted : so did a sense of belonging, a sense of place among peers, a sense ' you had made it '... you were normal and accepted. the social and development psychology played a very important part in the lives of soviet school children. pioneer rituals marked important turning points in the lives of generations of youngsters who did believe that they were building a new kind of society, a socialist society. receiving the pioneer ' s symbol the red tie, mixed joy in growing up and pride in joining the ranks of patriots of the new kind of state - the communist state. tatiana vorontsova explained the pride : " once you had the tie you had well, pride, it was like a flag. it is like when the flag flies. when you see the olympics and they start to raise your flag, you feel proud. and that pride is what we felt as children. you felt, " you ' ve got the tie! " in the massive social experiment that was the soviet union raising a new kind of person, soviet man ( homo sovieticus ), remained of paramount importance. new generations held the key to realizing ' a radiant communist future. ' for those marxists who insisted on creating the world ' s first classless society children meant everything. adults would repeat, " under communism there is only one privileged class - the children. " collective responsibility to a party ( comparative ) elder was learned from more senior classmates, the best teachers of lenin dogma proud to assert correct - thinking leadership that would keep others in line and bring them privileges. well - indoctrinated kids brimming full of propaganda could be mustered to help the bolshevik leaders deal with their fundamental problem - that the masses, the older generations, remained backwards. pioneers and members of the more select older young communists league ( koms


way some young pioneers in the 30s were attacked by orthodox ( believing children ) for wearing red scarves ( devil ' s whiskers ) and ( less often ) for violating the commandment to honor thy father and mother. the more stalinism took hold, the fewer such cases of suspect behavior are known. to survive people conformed. they kept silent. and the continuous propaganda worked. as a schoolgirl in the 1950s tatiana vorontsova remembers she learned the morozov lesson in the fourth grade. " so he died like a hero. we, of course, would also have liked to be heroes and at that time if i had been in the same situation, and my father had done something against the soviet state, of course, i would simply have gone and reported him, just like that. " in the terror filled days of his most ruthless rule stalin kept his own cult going. as he signed the death warrants for uncounted large numbers of his comrades and countrymen, the newspaper writers hailed him as the gentle wise leader. stalin ordered the party purged. professionals and leaders from all walks of life, army officers, astronomers, engineers, rocket scientists, writers, painters, were exiled to the gulag if they were not shot. terror filled whole apartment buildings, whole streets, whole towns as the nkvd suddenly appeared to drag people away to unknown fates. the very irrationality, unpredictability, and illogic of arrests, beatings, executions and exile made people feel the terror pervasively. state violence defined the stalinist state. denunciation or the possibility of denunciation even by one ' s own children plus the suspicion that devices such as radios could listen as well as transmit through wired speakers were daily reminders of the possibility of terror visiting a family, a neighbor, a friend. of course, by plucking off so many top leaders and lieutenants in most every field of endeavor stalin created a huge number of job openings. the new generation of people coming of age and education since the revolution seized ( and loved! ) the chance for upward mobility. yet through it all stalin encouraged worshipful respect of his portrait - it was everywhere - as lenin ' s heir and wise interpreter of scientific socialism. stalin had himself depicted by artists, writers, and propagandists as the knowing caring lover of soviet children and virtual equal of the soviet deity, lenin. those who knew about the terror, even prisoners themselves as true believer took comfort in thinking that stalin couldn ' t know.