موضوعات
آموزش و پرورش
ادبیات و زبان
پزشکی، دندانپزشکی و داروسازی
تاریخ و جغرافیا
داستان و رمان
دیگر
دین و فلسفه
روانشناسی
ریاضیات و آمار
سلامتی، تناسب اندام و رژیم غذایی
شیمی و پلیمر
علوم اجتماعی و حقوق
علوم زیستی و بیوتکنولوژی
فیزیک و نجوم
کامپیوتر و اینترنت
کتابهای کودکان و داستان
کسب و کار و اقتصاد
کشاورزی و دامپزشکی و غذا
معماری
مهندسی و فناوری
هنر و تئاتر
محصولات
Adaptive Optics for Vision Science Principles Practices Design and Applications - Original PDF
نویسندگان: خلاصه: The high transverse resolution of retinal imaging systems equipped with adaptive optics provides a unique opportunity to record these eye move- ments with very high accuracy. Putnam et al. showed that it is possible to record the retinal location of a fixation target on discrete trials with an error at least 5 times smaller than the diameter of the smallest foveal cones [63]. We used this capability to measure the standard deviation of fixation positions FIGURE 1.7 Images of the cone mosaics of 10 subjects with normal color vision, obtained with the combined methods of adaptive optics imaging and retinal densi- tometry. The images are false colored so that blue, green, and red are used to repre- sent the S, M, and L cones, respectively. (The true colors of these cones are yellow, purple, and bluish-purple). The mosaics illustrate the enormous variability in L/M cone ratio. The L/M cone ratios are (A) 0.37, (B) 1.11, (C) 1.14, (D) 1.24, (E) 1.77, (F) 1.88, (G) 2.32, (H) 2.36, (I) 2.46, (J) 3.67, (K) 3.90, and (L) 16.54. The proportion of S cones is relatively constant across eyes, ranging from 3.9 to 6.6% of the total population. Images were taken either 1° or 1.25° from the foveal center. For two of the 10 subjects, two different retinal locations are shown. Panels (D) and (E) show images from nasal and temporal retinas, respectively, for one subject; (J) and (K) show images from nasal and temporal retinas for another subject. Images (C), (J), and (K) are from Roorda and Williams [52]. All other images were made by Heidi Hofer. (See insert for a color representation of this figure.) (From Williams and Hofer [57]. Reprinted with permission from The MIT Press.) across discrete fixation trials, obtaining values that ranged from 2.1 to 6.3 arcmin, with an average of 3.4 arcmin, in agreement with previous studies [63, 64]. Interestingly, the mean fixation location on the retina was displaced from the location of highest foveal cone density by an average of about 10 arcmin (as shown in Fig. 1.8), indicating that cone density alone does not drive the location on the retina selected for fixation. This method may have interesting future applications in studies that require the submicron registra- tion of stimuli with respect to the retina or delivering light to retinal features as small as single cells. Whereas the method developed by our group can only record eye position on discrete trials, Scott Stevenson and Austin Roorda have shown that it is possible to extract continuous eye movement records from video-rate images obtained with an adaptive optics scanning laser ophthalmoscope (AOSLO) [66]. Eye movements cause local warping of the image within single video frames as well as translation between frames. The warping and translation information in the images can be used to recover a record of the eye move- ments that is probably as accurate as any method yet devised. This is illus- trated in Figure 1.9, which compares the eye movement record from the AOSLO with that from a Dual Purkinje Eye Tracker. The noise in the AOSLO trace is on the order of a few arc seconds compared to about a minute of arc for the Dual Purkinje Eye Tracker. Note also the greatly reduced overshoot following a saccade in the AOSLO trace. These overshoots are thought to be partly artifacts caused by lens wobble following the saccade and do not reflect the true position of the retinal image. The AOSLO is not susceptible to this artifact because it tracks the retinal position directly rather than relying on reflections from the anterior optics.
Killing Hope_ US Military and CIA Interventions Since World War II. Part 1-Zed Books Ltd (2003) - Original PDF
نویسندگان: خلاصه: Introduction A Brief History of the Cold War and Anti-communism Our fear that communism might someday take over most of the world blinds us to the fact that anti- communism already has. —Michael Parenti1 It was in the early days of the fighting in Vietnam that a Vietcong officer said to his American prisoner: "You were our heroes after the War. We read American books and saw American films, and a common phrase in those days was "to be as rich and as wise as an American". What happened?"2 An American might have been asked something similar by a Guatemalan, an Indonesian or a Cuban during the ten years previous, or by a Uruguayan, a Chilean or a Greek in the decade subsequent. The remarkable international goodwill and credibility enjoyed by the United States at the close of the Second World War was dissipated country-by-country, intervention-by-intervention. The opportunity to build the war- ravaged world anew, to lay the foundations for peace, prosperity and justice, collapsed under the awful weight of anti-communism. The weight had been accumulating for some time; indeed, since Day One of the Russian Revolution. By the summer of 1918 some 13,000 American troops could be found in the newly-born Union of Soviet Socialist Republics. Two years and thousands of casualties later, the American troops left, having failed in their mission to "strangle at its birth" the Bolshevik state, as Winston Churchill put it.3 The young Churchill was Great Britain's Minister for War and Air during this period. Increasingly, it was he who directed the invasion of the Soviet Union by the Allies (Great Britain, the US, France, Japan and several other nations) on the side of the counter-revolutionary "White Army". Years later, Churchill the historian was to record his views of this singular affair for posterity: Were they [the Allies] at war with Soviet Russia? Certainly not; but they shot Soviet Russians at sight. They stood as invaders on Russian soil. They armed the enemies of the Soviet Government. They blockaded its ports, and sunk its battleships. They earnestly desired and schemed its downfall. But war—shocking! Interference—shame! It was, they repeated, a matter of indifference to them how Russians settled their own internal affairs. They were impartial—Bang!4 What was there about this Bolshevik Revolution that so alarmed the most powerful nations in the world? What drove them to invade a land whose soldiers had recently fought alongside them for over three years and suffered more casualties than any other country on either side of the World War? The Bolsheviks had had the audacity to make a separate peace with Germany in order to take leave of a war they regarded as imperialist and not in any way their war, and to try and rebuild a terribly weary and devastated Russia. But the Bolsheviks had displayed the far greater audacity of overthrowing a capitalist- feudal system and proclaiming the first socialist state in the history of the world. This was uppityness writ incredibly large. This was the crime the Allies had to punish, the virus which had to be eradicated lest it spread to their own people. 6 The invasion did not achieve its immediate purpose, but its consequences were nonetheless profound and persist to the present day. Professor D.F. Fleming, the Vanderbilt University historian of the Cold War, has noted: For the American people the cosmic tragedy of the interventions in Russia does not exist, or it was an unimportant incident long forgotten. But for the Soviet peoples and their leaders the period was a time of endless killing, of looting and rapine, of plague and famine, of measureless suffering for scores of millions— an experience burned into the very soul of a nation, not to be forgotten for many generations, if ever. Also for many years the harsh Soviet regimentations could all be justified by fear that the capitalist powers would be back to finish the job. It is not strange that in his address in New York, September 17, 1959, Premier Khrushchev should remind us of the interventions, "the time you sent your troops to quell the revolution", as he put it.5 In what could be taken as a portent of superpower insensitivity, a 1920 Pentagon report on the intervention reads: "This expedition affords one of the finest examples in history of honorable, unselfish dealings ... under very difficult circumstances to be helpful to a people struggling to achieve a new liberty."6 History does not tell us what a Soviet Union, allowed to develop in a "normal" way of its own choosing, would look like today. We do know, however, the nature of a Soviet Union attacked in its cradle, raised alone in an extremely hostile world, and, when it managed to survive to adulthood, overrun by the Nazi war machine with the blessings of the Western powers. The resulting insecurities and fears have inevitably led to deformities of character not unlike that found in an individual raised in a similar life- threatening manner. We in the West are never allowed to forget the political shortcomings (real and bogus) of the Soviet Union; at the same time we are never reminded of the history which lies behind it. The anti-communist propaganda campaign began even earlier than the military intervention. Before the year 1918 was over, expressions in the vein of "Red Peril", "the Bolshevik assault on civilization", and "menace to world by Reds is seen" had become commonplace in the pages of the New York Times. During February and March 1919, a US Senate Judiciary Subcommittee held heatings before which many "Bolshevik horror stories" were presented. The character of some of the testimony can be gauged by the headline in the usually sedate Times of 12 February 1919: DESCRIBE HORRORS UNDER RED RULE. R.E. SIMONS AND W.W. WELSH TELL SENATORS OF BRUTALITIES OF BOLSHEV1KI— STRIP WOMEN IN STREETS—PEOPLE OF EVERY CLASS EXCEPT THE SCUM SUBJECTED TO VIOLENCE BY MOBS
A devil's chaplain: reflections on hope, lies, science, and love - Original PDF
نویسندگان: خلاصه: The first essay in this volume, A Devil's Chaplain (1.1), has not previously been published. The title, borrowed by the book, is explained in the essay itself. The second essay, What is True? (1.2), was my contribution to a symposium of that name, in Forbes ASAP magazine. Scientists tend to take a robust view of truth and are impatient of philosophical equivocation over its reality or importance. It's hard enough coaxing nature to give up her truths, without spectators and hangers-on strewing gratuitous obstacles in our way. My essay argues that we should at least be consistent. Truths about everyday life are just as much - or as little - open to philosophical doubt as scientific truths. Let us shun double standards. At times I fear turning into a double standards bore. It started in child- hood when my first hero, Doctor Dolittle (he returned irresistibly to mind when I read the Naturalist's Voyage of my adult hero, Charles Darwin), raised my consciousness, to borrow a useful piece of feminist jargon, about our treatment of animals. Non-human animals I should say, for, of course, we are animals. The moral philosopher most justly credited with raising today's consciousness in this direction is Peter Singer, lately moved from Australia to Princeton. His The Great Ape Project aims towards granting the other great apes, as near as is practically possible, civil rights equivalent to those enjoyed by the human great ape. When you stop and ask yourself why this seems so immediately ridiculous, the harder you think, the less ridiculous it seems. Cheap cracks like 'I suppose you'll need reinforced ballot-boxes for gorillas, then?' are soon dispatched: we give rights, but not the vote, to children, lunatics and Members of the House of Lords. The biggest objection to the GAP is 'Where will it all end? Rights for oysters?' (Bertrand Russell's quip, in a similar context). Where do you draw the line? Gaps in the Mind (1.3), my own contribution to the GAP book, uses an evolutionary argument to show that we should not be in the business of drawing lines in the first place. There's no law of nature that says boundaries have to be clear-cut.
Postcolonial and Postsocialist Dialogues - Original PDF
نویسندگان: خلاصه: Through staging dialogues between scholars, activists, and artists from a variety of disciplinary, geographical, and historical specializations, Postcolonial and Postsocialist Dialogues explores the possible resonances and dissonances between the postcolonial and the postsocialist in feminist theorizing and practice. While postcolonial and postsocialist perspectives have been explored in feminist studies, the two analytics tend to be viewed separately. This volume brings together attempts to understand if and how postcolonial and postsocialist dimensions of the human condition - historical, existential, political, and ideological - intersect and correlate in feminist experiences, identities, and struggles. In the three sections that probe the intersections, opacities, and challenges between the two discourses, the authors put under pressure what postcolonialism and postsocialism mean for feminist scholarship and activism. The contributions address the emergence of new political and cultural formations as well as circuits of bodies and capital in a post-Cold War and postcolonial era in currently re-emerging neo-colonial and imperial conflicts. They engage with issues of gender, sexuality, race, migration, diasporas, indigeneity, and disability, while also developing new analytical tools such as postsocialist precarity, queer postsocialist coloniality, uneventful feminism, feminist opacity, feminist queer crip epistemologies. The collection will be of interest for postcolonial and postsocialist researchers, students of gender studies, feminist activists and scholars.
Global perspectives on the biology and life history of the white shark - Original PDF
نویسندگان: خلاصه: With this book comes a historic change in the context of White Shark research. The relatively low abundance of this species, combined with its exceptional size and predatory nature, equated to a fish that was very hard to study. The introduction of White Shark research papers always included an obligatory statement that this species is rarely the focus of comprehensive studies and little is known of its basic biology and life history
Diagnostic Radiology Physics: A Handbook For Teachers And Students - Original PDF
نویسندگان: خلاصه: This book is dedicated to students and teachers involved in programmes that train professionals for work in diagnostic radiology. It teaches the essential physics of diagnostic radiology and its application in modern medicine. As such, it is useful to graduate students in medical physics programmes, residents in diagnostic radiology and advanced students in radiographic technology programmes.
Davidson’s Self-assessment in Medicine - Original PDF
نویسندگان: خلاصه: This book has been built around modern educational principles and utilises a contemporary assessment style, in line with current undergraduate and postgraduate teaching. It is designed to help and support students in their final undergraduate years and in the early years after qualification. The style is compatible with that used in modern postgraduate examinations across the world.
The sociology of community connections - Original PDF
نویسندگان: خلاصه: The Sociology of Community Connections is about how we interact and connect with one another as individuals and groups in a variety of social situations. We interact out of necessity and connect as a consequence of choice, and it is our connections that create community. Networks of communities that are interdependent, diverse, and responsive to change, yet cohesive, provide the infrastructure for a healthy society. In today's world, our societal infrastructure is continuously being tested by forces and demands that attempt to alter it, and thereby change the nature of how we connect within our various communities. We need to analyze these forces and demands and understand the impact they have on our connections so that, individually and collectively, we can create more social capital than we use. In the last decade, as the world has become smaller and more interdependent, the definition of community has changed. In our society--indeed, in the world--there seem to be more broken and fragmented relationships than in the past, an absence of connections where they appear to be needed, an uncertainty and lack of trust in relationships we have sustained, and a tendency to select, restrict, and even plan those connections that promote self-interest. This graduate-level text explains how our early connections and attachments are formed and discusses past and present conceptions of community. A major portion of the book describes how the sociology of connections takes place in a variety of communities such as: immigrant and ethnic communities, the fragmented communities of the poor and homeless, communities experiencing crises, communities of exclusion and excluded communities, religious communities, cyber communities and solitary communities. The Sociology of Community Connections is highly recommended for classes in sociology, social work, social and cultural anthropology, community psychology, communications, criminal justice, and urban planning.
Media Access; Social And Psychological Dimensions Of New Technology - Original PDF
نویسندگان: خلاصه: In Media Access: Social and Psychological Dimensions of New Technology Use, editors Erik P. Bucy and John E. Newhagen present the latest work, theoretical explorations, and original research findings on media access from a team of internationally renowned media and technology researchers. Chapters develop expanded definitions and conceptual understandings of access to stimulate further research, offer new perspectives on policy discussions, and facilitate media participation among those at risk of being left behind. Broadening our understanding of information technology use, this collection offers: *Novel perspectives--chapters demonstrate new methods of addressing persistent questions regarding motivation, cultural context, socioeconomic resources, technical knowledge, and psychological skills required for effectual use of information and communication technologies. *Conceptual integration--each chapter addresses a vital aspect of media access and summarizes pertinent findings, weaving together results to provide much-needed integration across communication and technology studies. *Multidisciplinary approaches--chapters represent a variety of conceptual and methodological approaches, deriving social explanations from large-scale survey data, psychological explanations from experimental data, and cultural explanations from depth interviews and ethnographic methods. *Shifting the policy and research agenda--this volume extends and redirects aspects of the digital divide debate while elaborating the "media access" approach to studying new technology use. Taken as a whole, Media Access reveals complications associated with full access to new communication technologies and proposes analytical frameworks that open new avenues of scholarly investigation and policy consideration. It is intended for scholars and graduate students in journalism, mass communication, telecommunications, media studies, information science, public policy, psychology, sociology, informatics, human-computer interaction, and other disciplines concerned with the issue of media access.آیا کتاب مورد نظر هنوز بر روی سایت قرار نگرفته است؟ جای نگرانی نیست! کافی است بر روی گزینه سفارش کتاب کلیک کرده و درخواست خود را ثبت کنید. در کمتر از چند ساعت کتاب شما را آماده خواهیم کرد.