| Achieving Health in a Connected World |
| Dietary Flavonoids: Heart-Healthy Nutrients or an Excuse to Enjoy Wine and Chocolate? Friday, February 15, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| John W. Erdman Jr., University of Illinois; Bernard Chaitman, St. Louis University School of Medicine | |||||||||||||||
| Some wines, chocolates and other plant-based foods contain substantial amounts of flavonoids, a naturally-occurring class of compounds with a wide range of biological activities, including antioxidant activity, that have implications for health. Recent advances in medical and nutritional research suggest that certain of these flavonoids can play an important role in maintaining cardiovascular health. New data will be presented in this context which will have the potential to influence thinking within the nutrition and public health community as to whether this class of non-essential plant compounds may in fact be important for optimal cardiovascular health. Specific aspects of flavonoid research covered include new epidemiological, clinical, biological and compositional data, as well as a review of the recent and important clinical and biological findings. This symposium provides a forum for debate and discussion as to what further evidence will be required to determine whether flavonoids are dietary essentials or simply good markers for consumption of plant-based foods. | |||||||||||||||
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| New Drugs for Cytomegalovirus Infections in Birth Defects and AIDS Saturday, February 16, 2002 2:45 p.m. - 4:15 p.m. | |||||||||
| John C. Drach, University of Michigan | |||||||||
| Infections with human cytomegalovirus (HCMV) are the cause of significant human morbidity and mortality. Although HCMV infections have been present for untold years, the advent of the AIDS pandemic resulted in a virtual eruption of disease on a world-wide basis. Initial infection in immunocompetent individuals usually produces only mild disease or is asymptomatic. In contrast, infection in utero, of neonates, of individuals infected with human immunodeficiency virus (HIV) or immunocompromised for other reasons results in birth defects, compromise of major organs, debility, and death. This symposium addresses efforts of the last several years to develop and deploy drugs for the treatment of infections caused by HCMV. Topics cover the range of scientific disciplines needed to discover and develop drugs to treat these diseases. Significant and recent research on the synthesis of new compounds, the molecular biology of the virus, molecular drug targets, modern drug development, and clinical investigation will be presented. | |||||||||
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| Scientific & Ethical Perspectives on the Risks of HIV/AIDS Therapeutics Saturday, February 16, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| Rochelle Diamond, National Organization of Gay and Lesbian Scientists and Technical Professionals, California Institute of Technology; Stephanie J. Bird, Massachusetts Institute of Technology | |||||||||||||||
| Combination HIV-1 treatments are effective inhibitors of AIDS progression and also help to prevent maternal-fetal transmission of the virus (~70% reduction). Patients live longer, healthier lives and many children who are born of HIV+ mothers are sero-negative. There are, however, potential short and long-term risks involved with the use of these nucleoside-analog reverse transcriptase inhibitors (NRTI). The molecular mechanisms responsible for their effectiveness (incorporation into nuclear and mitochondrial DNA-) also mediate their potential toxicity and possible genetic/germline DNA repercussions. The potential risks for long-term health effects of in utero NRTI exposure have not yet been evaluated, although the pharmaceutical industry has established the Antiretroviral Pregnancy Registry that will follow the health of these children over time. Long-term genetic effects during development and into adulthood in children conceived with NRTI-treated sperm are unknown and may be different from effects seen in children treated in utero. Nevertheless, because of the success of these antiviral therapies, some HIV+ men are choosing to have offspring. The communications media have broadcast stories about doctors and clinics that utilize sperm washing and assisted reproduction techniques in order to allow HIV+ patients to have children without transmitting the virus to their partners or children. The complex and problematic pasts of the drugs thalidomide and diethylstilbesterol (DES), both of which have had serious consequences when used during pregnancy, highlight medical and ethical issues that merit public attention and discussion in relation to NRTI treatment. | |||||||||||||||
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| The Present State of Genomic Medicine Friday, February 15, 2002 2:30 p.m. - 5:30 p.m. | ||||||||||||||||||
| Jeffrey Drazen, New England Journal of Medicine; Francis S. Collins, National Center for Human Genome Research, National Institutes of Health | ||||||||||||||||||
| This symposium is to discusses and elucidates progress at the interface between medical practice and genomic science. It highlights the interface between the basic science of genetics and the uses of this information to aid in the diagnosis and treatment of patients. The symposium will be in two parts: The big picture, i.e. how we use genes and genetic techniques to further our knowledge of clinical phenotypes, and a closer look at some specific diseases and disease types. The talks will focus on the state of medical genomics at the present time. What can we actually do to screen, diagnose and treat human disease right now? The presentations will be based on specific examples of diseases and treatments. | ||||||||||||||||||
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| Winning the War on Cancer in the Post-Genomic Era Monday, February 18, 2002 9:30 a.m. - 12:30 p.m. | ||||||||||||||||||
| Kevin Davies, [Cell Press] | ||||||||||||||||||
| Since President Nixon’s famous declaration of a “War on Cancer” 30 years ago, scientists have made enormous strides in understanding the basic mechanisms of cancer, and devising new treatments for effective therapy. We now have a detailed appreciation of the genetic causes of cancer, in both its inherited and sporadic varieties. Emerging new technologies such as DNA microarrays are leading to exciting progress in the diagnosis of cancerous lesions at the molecular level. And the astounding success of Gleevec offers a glimpse of a new era of rational drug targeting in cancer. As gratifying as these advances are, there is still an enormous gap between our appreciation of the molecular basis of tumorigenesis and our ability to translate these advances into genuine cures. This year in the United States alone, an estimated 1.25 million people will be diagnosed with cancer for the first time, and cancer still accounts for almost 25 percent of all deaths in the United States. The speakers at this symposium — all undisputed leaders in cancer research —have contributed greatly to recent progress. They will describe the latest findings in our understanding of the genetic basis of the disease, and showcase some of the most promising new diagnostic and therapeutic strategies that will ultimately change the course of the war on cancer. | ||||||||||||||||||
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| Nutritional Interventions for Cancer Survivors Tested in Clinical
Trials Monday, February 18, 2002 2:45 p.m. - 4:15 p.m. | ||||||||||||
| R. Jean Hine, University of Arkansas for Medical Sciences | ||||||||||||
| The estimated nine million Americans who have survived a cancer often seek information about how diet and dietary supplements might influence the recurrence of their diseases. In addition, many people who have precancerous lesions also ask whether dietary changes might prevent progression of these conditions into cancer. Until recently, these individuals and their health care providers have been frustrated by the lack of data available to supply clues about how or if nutritional variables affect progression of premalignant lesions and event-free or overall survival of cancer patients. Advances in the development of techniques to assess biological markers and identify genetic mutations and phenotypic changes now permit scientists to study the complex effects of dietary factors on recurrence of human cancers. Emerging data from epidemiological and laboratory studies suggest that these variables may indeed influence the progression or recurrence of some cancers. Recognizing this, the National Institutes of Health (NIH) now supports large-scale, multi-site clinical trials that are investigating the effects of nutrition on cancers. This symposium examines the research questions and current evidence associated with three of these trials. Two of the studies are investigating the effect of diets rich in vegetables, fruit and fiber and low in fat on breast cancer recurrence. The third research study is determining if selenium and vitamin E supplements can prevent prostate cancer. These trials are unique because they represent the largest effort to date to measure the effect of nutrition on the biology of specific cancers. | ||||||||||||
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| Dental Cavities: A New Look at an Old Problem Saturday, February 16, 2002 8:45 a.m. - 10:15 a.m. | |||||||||||||||
| Marc W. Heft, University of Florida | |||||||||||||||
| Dental caries is an ancient disease dating back to emergence of agriculture as the primary source of food. While recently the overall incidence of dental cavities has been declining in the general population, there is evidence that dental cavities still remains common is the U.S. The program is directed toward a general audience and will provide a general overview of the biological, social and behavioral factors associated with the occurrence of dental caries and novel strategies to address this problem. The first two presenters will frame the problem. First by providing an understanding of the racial, SES and other factors associated with disparities in incidence and prevalence of dental cavities. Second by providing an understanding of dental caries as an infectious disease process that is modulated by saliva and other host-defense mechanisms. The two remaining speakers will address issues related to the control of dental caries. One will describe a novel approach to the control of dental caries by genetically modifying bacterial strains within the oral ecosystem. The other will provide a current assessment of the highly successful and cost-effective water fluoridation. | |||||||||||||||
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| The Science Underlying Complementary and Alternative Medicine Sunday, February 17, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| Stephen E. Straus, National Institutes of Health; Donald J. Krogstad, Tulane University; Sondra Schlesinger, Washington University School of Medicine | |||||||||||||||
| Americans are setting aside prescription drugs and picking up bottles of herbs; they visit chiropractors and acupuncturists. A mix of ancient, empirically derived wisdom and slick marketing have found their place in the contemporary health care arena. Lacking a scientific tradition, these complementary and alternative medicine (CAM) approaches offer promises but too little proof. This symposium will explore the breadth of CAM practices, their current appeal, and the strategy by which the NIH is bringing tools of exacting science to bear on some of the more important and most fascinating observations in the field. In the three years since creation of the National Center for Complementary and Alternative Medicine at the NIH, its staff has spent an enormous amount of time convincing both sides in this debate that they and the NIH have a commitment to objectively evaluating this important area by providing support (with a budget for extramural research that is now approaching 00M) for randomized clinical trials, as well as basic research, and endeavoring to enlist the brightest and most competitive investigators that can be identified to assist in this process. This approach is paying dividends, as is illustrated by the speakers here. | |||||||||||||||
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| The Many Facets of Aging Research Saturday, February 16, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||
| Kelly LaMarco, AAAS’s Science of Aging Knowledge Environment; Huber Warner, National Institute on Aging, National Institutes of Health | |||||||||||||||
| Over the last several years, research in the field of aging has flourished. "Aging" research includes diverse fields of study, such as hormonal signaling; DNA repair; neurodegeneration; evolution; and the molecular basis of obesity, diabetes, and cancer. Increasing numbers of scientists who began their careers studying such basic biological processes have forayed into aging-related research as molecular connections between specific biological pathways and aging became apparent. This symposium includes researchers such as these working in the following areas: insulin/IGF1 signaling; DNA repair; evolution of life-span; neurological aging; and obesity/diabetes. In addition to their research, presenters also will describe how they came to be interested in "aging" as a field of study. | |||||||||||||||
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| Environmental Estrogens and Women’s Health Friday, February 15, 2002 2:30 p.m. - 5:30 p.m. | |||||||||||||||
| Nancy Reame, University of Michigan | |||||||||||||||
| In the last decade there has been heightened interest and confusion about the role of estrogenic compounds in the etiology of women’s health problems. Although hormone replacement therapy has been proposed for the prevention and treatment of many chronic conditions, ranging from osteoporosis and heart disease, to urinary incontinence and dementia, there is increasing evidence of the dangers associated with too much exposure not only from standard regimens and dietary supplements used to treat menopause, but also from a growing array of estrogen mimics in the environment. From precocious puberty to birth defects to breast cancer, these endocrine disruptors have been blamed for the apparent rise in reproductive dysfunction in animals and humans. This year, the National Toxicology Program’s Board of Scientific Counselors decided to list all steroidal estrogens as a cause of cancer in their federal Report on Carcinogens scheduled for publication next year. To what extent this ruling will influence women’s decision-making about hormone exposure remains to be seen. This 4-topic symposium aims to examine the current scientific evidence for the role of environmental influences on women’s health across the life span as a way to better understand the context and nature of the dangers and benefits of hormone exposure. | |||||||||||||||
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| Stem Cell Biology: From Basic Research to Clinical Opportunity Monday, February 18, 2002 9:30 a.m. - 12:30 p.m. | ||||||||||||||||||
| Laura Grabel, Wesleyan University | ||||||||||||||||||
| Recent advances in stem cell biology have led to new hopes for therapies of human genetic and other degenerative diseases. The advances that have led to these expectations will be reviewed and placed in perspective. Speakers are major contributors to current progress in basic research leading towards achieving the therapeutic promise of cultured embryonic and adult stem cells. The major issues that will be addressed include the problem of directing the differentiation of pluripotent stem cells, the problem of tissue engineering, and the immune problem. Going beyond cell-based therapies, how do we deal with the access to modification of the human genome that is implicit in the existence of human embryonic stem cells? Thus, a consideration of ethical implications of stem cell research is included in the presentations. | ||||||||||||||||||
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| Challenges for Meta-Analysis to Connect Disparate Health Care Evidence Saturday, February 16, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||
| Ingram Olkin, Stanford University | |||||||||||||||
| In 1940 there were approximately 2300 biomedical journals worldwide. This number is closer to 40,000 today, and the effect of electronic publication is still to be evaluated. This degree of growth is reasonably stable over fields. Although search methods are available, the sheer bulk of publications make it difficult to assess the state of efficiency in medicine. There have been several responses to this problem. One such is to create a repository of the results of independent studies being conducted throughout the world. This movement has been termed evidence-based medicine. However, this presupposes the existence of a methodology that permits drawing conclusions from these studies. This methodology is currently being developed as it applies to different scientific areas. This symposium focuses on several themes related to health care evidence and policy: meta-analysis in drug development and from a regulatory point of view; meta-analysis in the social sciences compared to medicine; large trials versus multiple small trials; the role of randomization in evidence; how strong is evidence from observational studies. | |||||||||||||||
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| Alzheimer's Disease Pathogenesis, Diagnosis, and Therapeutics Tuesday, February 19, 2002 8:00 a.m. - 11:00 a.m. | ||||||||||||
| Rudolph E. Tanzi, Massachusetts General Hospital | ||||||||||||
| Alzheimer's disease (AD) is the most common form of dementia in the elderly and is becoming increasingly more prevalent as human longevity is extended . Over the last decade, immense progress has been made in efforts to understand the etiological and genetic underpinnings as well as the pathogenic pathways involved in this insidious neurodegenerative disorder. This symposium will present the newest findings on AD research, diagnostics, and therapeutics from world leaders in this field. The newest research findings in the areas of genetics, cell and molecular biology, biochemistry, and animal models are covered with special emphasis on the search for novel AD genes and particularly the role of beta-amyloid fibrils and deposits in AD neuropathogenesis. Timely coverage of the newest and most effective means for diagnosis and prediction of AD also are presented together with the newest developments in the areas of prevention and therapeutic intervention of this devastating neurological disorder. | ||||||||||||
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| Bioterrorism in a Threatening World Sunday, February 17, 2002 3:00 p.m. - 6:00 p.m. | ||||||||||||
| Barry R. Bloom, Harvard School of Public Health | ||||||||||||
| Bioterrorism is an ancient and modern threat. For centuries governments, groups, and individuals have used biologic agents to achieve dominance over others…often with significant success. Modern technologies provide the ability to refine and develop many of these agents into significant, potentially devastating weapons. While there may be inherent dangers with such development, these agents may often be surprisingly easy to deliver to small groups or individuals, as the experiences this fall have shown. The threat and actuality of bioterrorism raise significant questions about the technologies for development and delivery of such agents as well as the readiness of national public health infrastructures to detect and address incidents, whether limited or widespread. Related to this is the development of a clear and accurate public understanding of the threats and suitable responses to incidents of bioterrorism. | ||||||||||||
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| Brain, Mind, and Behavior |
| Does the Language We Speak Affect the Thoughts We Think? Sunday, February 17, 2002 9:00 a.m. - 12:00 noon | ||||||||||||||||||
| Susan Goldin-Meadow, University of Chicago; Lila R. Gleitman, University of Pennsylvania | ||||||||||||||||||
| Languages across the globe vary in how they classify experience. Do such variations in classification affect the way people learn and use language? And do they have broader effects on thought and behavior? Benjamin Whorf popularized the notion that linguistic classifications might influence not only how we talk about the world, but also how we think about the world when not speaking. In other words, a speaker's habitual use of a meaningful categorization scheme when talking might affect how that individual categorizes and understands the world even when not talking. In this view, differences across languages help shape the thoughts of their users, and play a powerful causal role in cognitive and cultural diversity. This position fell into disfavor owing in large part to the influence of Noam Chomsky. Chomsky's conception of linguistic theory as positing an innatist account of language acquisition has encouraged a universalist view of the mapping between thought and language. Empirical tests probing this question have not proven convincing to either side in the debate. What has emerged recently is a more systematic effort on both sides seeking to ground the discussion in better empirical efforts. This effort, illustrated in this symposium, involves comparisons across languages and tasks, and across speakers who have and have not been exposed to language. From such an approach, we will not get a yes/no answer to Whorf's thesis but will gain a richer understanding of the complex interaction between language and thought, while setting boundary conditions on the applicability of the hypothesis. | ||||||||||||||||||
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| Avian Cognition: When Being Called "Bird Brain" Is a Compliment Friday, February 15, 2002 9:00 a.m. - 12:00 noon | ||||||||||||||||||
| Irene M. Pepperberg, Massachusetts Institute of Technology; Russell P. Balda, Northern Arizona University | ||||||||||||||||||
| Humans have a long, conflicting history concerning judgments of nonhuman cognitive abilities. Although the phylogenetic closeness of great apes to humans and large brains of cetaceans lead us to anticipate and accept that their communicative and cognitive capacities will resemble those of humans, analogous abilities have not been expected in birds. Over three decades of controlled experimental studies have, however, documented a host of impressive avian cognitive traits. These finding are the result of the "cognitive revolution", which inspired psychologists and behavioral ecologists to move beyond the world of simple S-R models and conditioning, sign stimuli, and innate releasing mechanisms to explore and more openly test a wide range of phenomena. Consequently, animals are no longer viewed as simple, stimulus-bound responders, passive learners or robotic followers of conditioning regimes, but rather as having the ability to collect and retain large amounts of information about their social and physical environments, and to process and use this information to survive. Cognition, like morphological and physiological traits, can thus be viewed as adaptive, shaped by natural selection and as part of the arsenal with which animals cope with the selective pressures imposed by complex, dynamic worlds. Speakers in this symposium explore and emphasize new findings in several specific areas of avian cognition--spatial, social, vocal. This symposium demonstrates that many avian species, despite brain architectures that lack much cortical structure and evolutionary histories and that differ so greatly from those of humans, equal and sometimes surpass humans with respect to various cognitive tasks. | ||||||||||||||||||
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| How Infants Begin to Learn Words: Cognitive and Perceptual Factors Sunday, February 17, 2002 2:45 p.m. - 4:15 p.m. | |||||||||||||||
| Peter W. Jusczyk, Johns Hopkins University; Sandra R. Waxman, Northwestern University | |||||||||||||||
| A critical step in acquiring any language is to learn its words. Until recently, the study of infants' word learning abilities was focused almost exclusively on infants' productions of words. However, the development of new methodologies has made it possible to explore infants' abilities to comprehend words. It is now clear that infants begin to store information about the sounds and meanings of words much sooner than was anticipated, namely, during the latter half of the first year. Word learning draws on a number of perceptual and cognitive abilities. Because most of the words they hear occur in the context of multiword utterances, infants must have some ability to segment words from fluent speech. In addition, because different words often have similar sound patterns (e.g."cat", "pat", "cap") infants must be able to perceive subtle distinctions among words, and to store accurate information about the sound patterns of different words. Critically, infants must link each distinctive sound pattern to its appropriate meaning in the world. How and when do infants decide whether a particular sound pattern is a name for a particular individual (such as "Fido") or to an entire class of objects (such as all dogs)? The research presented in this symposium suggests that many of the individual prerequisite abilities for word learning are in place in the first year. However, the successful coordination of these individual abilities is not immediately achieved and depends on the availability of adequate cognitive resources to integrate different streams of information. | |||||||||||||||
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| The Biology of Consciousness Friday, February 15, 2002 2:30 p.m. - 5:30 p.m. | ||||||||||||
| Chris Frith, University College London | ||||||||||||
| One of the fundamental facts of being human is that we are conscious; we are aware of the world about us and of our own inner states. Yet, until recently this consciousness was not considered a suitable topic for scientific study. The speakers in this symposium show that it is now not only possible to use scientific methods to study consciousness, but also to ask sensible questions about its biological basis. A key discovery has been that much of our behaviour occurs without awareness. We can reach for an object without being conscious of what we are doing. We can react to a face without being conscious of that face. On the other hand, simply imagining a face causes specific changes in brain activity. Given these observations we can ask a number of questions. A) Is there a special kind of brain activity that only occurs when we are conscious of something and differs from the activity that occurs when we react to something without aware? Such activity would provide a neural signature of consciousness. B) Humans with severe brain damage and animals cannot tell us about their experiences. How can we tell if they are conscious or if they are just behaving without awareness? C) If much of our behaviour can occur without awareness why do we need consciousness ? How did consciousness evolve? What does it enable us to do? These are all questions that the scientific study of consciousness can answer. | ||||||||||||
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| Images of Mind: Understanding How the Brain Enables Cognition Saturday, February 16, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| Randy L. Buckner, Washington University, Howard Hughes Medical Institute | |||||||||||||||
| Brain imaging methods provide a window through which to view the neural underpinnings of cognition. Moreover, recent methodological refinements in brain imaging allow images to be formed from momentary changes in neural activity providing unprecedented experimental flexibility that is fueling research on attention, language, emotion, and memory. In this symposium, leading researchers discuss recent brain imaging studies on these topics. Several broad questions are addressed including how language develops in children, how semantic information (facts about the world) are stored and accessed, how memories for episodes are formed, how attentional networks monitor ongoing task demands, and how emotional information is represented. Particular focus will be placed on new insights emerging from brain imaging research that extends beyond findings from previously available techniques. | |||||||||||||||
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| The Cognitive Neuroscience of Mental Imagery Saturday, February 16, 2002 2:45 p.m. - 4:15 p.m. | |||||||||
| Stephen Kosslyn, Harvard University | |||||||||
| Visual mental imagery is a quintessential "cognitive" event, but until recently has often been considered a marginal field of scientific study. The key problem was that imagery is an inherently private affair, accessible only to introspection. Unlike memory, language, reasoning, or other cognitive events, there are no signature behaviors and studies using transcranial magnetic stimulation that always reflect the presence or operation of mental imagery. The advent of neuroimaging has dramatically altered this landscape. For the first time in history, researchers can catch glimpses of mental images in action, and dramatic progress has been made in understanding the nature and function mental imagery. Neuroimaging studies, combined with studies of patients with brain damage have shown that images recruit most of the same brain areas used in perception-but not all. Thus, in many ways images can "re-present" (stand in) for actual objects, causing the same effects on memory and the body as occur during actual perception. However, the two functions are not identical, and only now are the similarities and differences between imagery and perception becoming evident. The emerging understanding of mental imagery holds the key to applications of imagery in clinical treatment of depression, phobias, and anxiety disorders, as well as the treatment of pain; it also holds the key to applications of imagery in enhancing learning and memory as well as aiding athletes to perform more effectively. | |||||||||
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| The Prefrontal Cortex and Cognition: New Insights into Willful Behavior Friday, February 15, 2002 9:00 a.m. - 12:00 noon | ||||||||||||
| Earl Miller, Massachusetts Institute of Technology | ||||||||||||
| What controls your thoughts? How do you decide what to pay attention to? How do you know how to act appropriately while dining in a restaurant or listening to a lecture? How do you plan your day or even a simple errand? This is cognitive control; the mechanisms by which your brain wrests control of its processing from reflexive reactions to the environment in order to direct it toward future aims. This is a hallmark of intelligent behavior and it reaches its apex in humans along with the elaboration of a particular brain region, the prefrontal cortex. It has been known for at least 150 years that damage to this brain region disrupts capacities that are associated with thoughtful, intelligent behavior: the ability to ignore distractions, keep on task, hold items in mind, and control impulses. New theoretical and empirical tools are making it possible, for the first time, to study the relationship between cognitive processes and their underlying neural mechanisms. Increased sophistication in behavioral, neurophysiological, and neuroimaging techniques has provided fodder for development of computational and conceptual models of cognitive control, which in turn, has constrained and inspired further theoretical advancements. As a result, we are now beginning to understand one of the deepest mysteries of the brain: how willful behaviors emerge from interactions between millions of neurons. This symposium highlights these recent developments by bringing together researchers who are at the forefront of experimental, computational, and conceptual efforts to understand cognition. | ||||||||||||
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| Sleep and Memory Tuesday, February 19, 2002 8:00 a.m. - 11:00 a.m. | |||||||||||||||
| Matthew Wilson, Massachusetts Institute of Technology | |||||||||||||||
| Recent research has shed new light on the possible role of sleep and its contribution to the formation of long term memory. This session explores studies of sleep and memory from a human neuropsychological, behavioral electrophysiological, and cellular and molecular perspective bringing together work in human and animal memory studies with topics of hippocampal-neocortical communication, developmental plasticity and the significance of sleep, and the significance and regulation of sleep rhythms as they might relate to the regulation of functional plasticity and intracortical communication. Novel techniques of regional molecular genetic manipulation that are capable of targeting cortical, hippocampal, and thalamic regions coupled with multiregional behavioral electrophysiological measurement of memory reactivation in the hippocampus and neocortex will be examined with particular emphasis on their relationship to long term memory consolidation. | |||||||||||||||
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| How the Brain Selects Objects and Commands Movement Sunday, February 17, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||
| Peter Schiller, Massachusetts Institute of Technology | |||||||||||||||
| Our interaction with objects in the world is an ever ongoing, stepwise process during our waking ours that involves numerous neural computations. The process begins with sensory analysis that includes the recognition of the objects in the scene and their localization in space. This is followed by the selection of one of the objects to which we intend to make a response. Motor signals are then generated to produce eye, head and limb movements toward this object. Recent work has made great progress in understanding how the brain realizes these objectives. This symposium delineates the current advances made in the field. Speakers will describe the role various neural structures play in this process, will infer how specific they are, will delineate how they interact, and will identify the coding operations involved. The neural structures under consideration by the speakers include regions of the spinal cord, the superior colliculus, areas V1, V2, V4, the middle temporal area, the lateral parietal sulcus, the motor and pre-motor cortices, the frontal eye fields and the medial eye fields. The work is based predominantly on research carried out utilizing recordings from single neurons, microstimulation, pharmacological manipulation, and tissue inactivation. | |||||||||||||||
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| Reconciling Expressivity and Tractability: Finite-State Methods in Natural Language Analysis Monday, February 18, 2002 9:30 a.m. - 12:30 p.m. | |||||||||||||||
| Lawrence S. Moss, Indiana University; Dick Oehrle, YY Technologies for the Mathematics of Language | |||||||||||||||
| The 'holy grail' of mathematical and computational linguistics is a linguistic formalism which is both computationally nice and expressively adequate. However, the formalisms that we have exhibit a kind of trade-off: the better the formalism, the harder it is to compute with. The first place this shows up is in the theory of finite-state (or regular) languages. It is elegant, widely applicable, and computationally pleasant. Yet it is inadequate for linguistics. This Symposium studies what are now called finite-state methods. Many interesting aspects of natural language are finite-state in this bigger sense, and we still have nice computational formalisms. This symposium will first review the theory of regular languages, emphasizing both the advantages and limitations of this approach. It then shows applications of finite-state methods in areas such as morphology (word structure), syntax, and the representation of linguistic events as annotation graphs. The wealth of current work from this perspective illustrates a renaissance. We'll communicate the theoretical perspective motivating this area, its success in applications, and especially, how it addresses the conflicting advantages of expressive power and computational tractability. This is the second in a series of AAAS Symposia designed to heighten general scientific awareness of mathematical investigations of natural language structure and processing by focusing on a particular area of research associated with the Mathematics of Language group. MOL is a special interest group of the Association for Computational Linguistics. | |||||||||||||||
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| Language and Brain: Electrophysiology and Imaging Rewrite
Aphasia-Based Models Saturday, February 16, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| Merrill Garrett, University of Arizona; David Caplan, Massachusetts General Hospital | |||||||||||||||
| How is the capacity for human language expressed in neural systems? This question has its historical roots in the study of language pathologies. Such evidence has provided a framework of general claims for the association of specific regions of the left hemisphere with core linguistic capacities. New research on both normal and impaired language performance using brain imaging and electrophysiological observation during language generation and comprehension has amplified and sharply modified classic claims for brain specializations based on neuropathologies of language. Some of the recent results are: Brain structures not previously identified with language have been implicated in such functions. Syntactic processes historically associated with Broca's area also manifest effects in posterior areas of perisylvian cortex. Distinct subareas within Broca's area are associated with different language processes. Areas adjacent to, but not part of Broca's area, are implicated in syntactic aspects of language generation. Moreover, there is an interaction between developmental processes and localization effects in early acquisition. Degree of left hemisphere specialization is apparently affected by the age of acquisition for a given language. The symposium reviews these and other findings, with special emphasis on the role of cross-linguistic data. Speakers will present results from a variety of languages (e.g., English, German, Dutch, Japanese, ASL). | |||||||||||||||
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| Speaking, Signing, Reading: Brain Systems that Support Language Use Monday, February 18, 2002 9:30 a.m. - 12:30 p.m. | |||||||||||||||
| Philip Rubin, National Science Foundation; Kenneth R. Pugh, Yale University School of Medicine | |||||||||||||||
| Among the many extraordinary facts about human language, one of the most striking is the range of its exercise. Speech is the dominant form of language use. But other modalities show powerful and flexible exercise of language skills. Reading and writing of diverse forms attain a speed and accuracy that matches that of the basic speech systems. Even more strikingly, natural signed languages (e.g., ASL, and other signed languages) have arisen in deaf communities. Systematic study has shown these to be fully-fledged languages with all the structural rigor and expressive power of spoken languages. Many classes of evidence demonstrate that these diverse capacities are the product of innately specified constraints on the structure of human languages coupled with powerful systems of learning and adaptation. How do nature and nurture work together to allow this remarkable range of expression? Which areas of brain do these diverse skills have in common? Where do they differ? How does experience affect their expression? Studies that use brain imaging (e.g., fMRI, PET) to identify neural systems for exercise of speech and language can be combined with studies of speech and reading pathologies to provide answers to these and related questions. | |||||||||||||||
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| Rethinking the Role of Affiliation and Aggression in Primate Groups Friday, February 15, 2002 2:15 p.m. - 3:45 p.m. | |||||||||||||||||||||
| Robert W. Sussman, Washington University; Karen B. Strier, University of Wisconsin | |||||||||||||||||||||
| With one exception, all diurnal primates live in social groups. Within these groups, affiliative and cooperative behaviors are far more frequent than agonistic behavior. It is commonly believed that positive social interactions are a reaction to competition necessitated by group living or that they serve as reconciliatory behaviors between competing individuals. However, if conditions favor cooperative behavior and these outweigh any negative conditions, natural selection could favor cooperative social interactions "in their own right". This panel discussion will present data from a number of taxa together with a genetic model that lends support to this hypothesis. Mother-infant interactions and play behavior will be shown to be among the proximate mechanisms that define the parameters of species typical patterns of sociality. This approach may lead to a better understanding of evolutionary foundations of affiliative behavior among humans as well as non-human primates. | |||||||||||||||||||||
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| New Neurons in the Adult Brain: Disease, Injury, and Repair Monday, February 18, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||
| Fred H. Gage, Salk Institute; Jeffrey D. Macklis, Harvard Medical School | |||||||||||||||
| Neurogenesis, the birth of new neurons, normally occurs in the adult mammalian brain in only two evolutionarily old regions, the olfactory bulb and the hippocampus, involved in memory. Neurons are born in these regions even in higher adult mammals, such as monkeys and humans. Much has been learned over the past few years about the cellular sources of such neurogenesis; about natural modulators of the extent of neuron birth and survival (e.g. learning, activity, novelty of the environment, age, gender, and hormonal status); and about the physiologic role of new neurons. Why do some neurons continue to be replaced in adult brains? What role do they play in normal brain function, in disease, and following injury? Is it possible to manipulate the precursors, or stem cells, that give rise to these new neurons in the hippocampus and in regions of the brain where neurogenesis does not normally occur, toward the goal of brain repair? These and other questions are fueling much debate and active investigation. The cellular and molecular controls over neurogenesis and its component steps-proliferation, migration, differentiation, survival, and functional connectivity - are being actively investigated. The adult brain possesses much more plasticity than previously thought, but much remains to be learned about the limits and precise control of this plasticity. It appears that there could be remarkable potential for control of neuron birth and incorporation in the normal, diseased, and injured adult brain, if cellular and molecular controls over these events can be harnessed and manipulated. | |||||||||||||||
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| Communicating Across Boundaries |
| International Trends in the Transfer of Academic Research Monday, February 18, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||||||||||||||
| Irwin Feller, Pennsylvania State University; Fabio Pammolli, University of Siena | |||||||||||||||||||||||||||
| Internationally, universities are taking on increasingly greater roles as sources of commercially relevant technologies and, relatedly, for national and regional economic growth. Moving beyond descriptive catalogues of national policies and institutional practices, a growing body of research has identified significant variations across nations in the techniques used by universities to transfer academic research to the marketplace. The choice or portfolio of technology transfer techniques, such as patents and licenses, equity holdings, spin-off firms, research parks, leveraged sponsored research, and others, is increasingly being interpreted in terms of strategic behaviors on the parts of universities, firms, and governments. These behaviors, in turn, are conditioned by national and regional legislation and policies, national patterns for funding higher education and academic research, and historic patterns of university-industry collaborative research and development. | |||||||||||||||||||||||||||
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| The New Biology of Rocks Friday, February 15, 2002 2:30 p.m. - 5:30 p.m. | |||||||||||||||
| Abigail Salyers, University of Illinois, Urbana-Champaign; James T. Staley, University of Washington | |||||||||||||||
| Through evolutionary time, Earth’s biota has profoundly interacted and altered the geology of our planet. Interactions among the geosphere, atmosphere, and biosphere are so important that the evolution of life on Earth cannot be separated from the evolution of the non-living planet. The boundaries of geobiology, the science that deals with this intersection, are expanding and includes an array of diverse topics, ranging from the molecular basis of mineral formation and dissolution to the detection, diversity, and evolution of life in remote locations; biogeochemical extremes in gradients; and control of biogeochemical cycles over vastly different temporal and spatial scales. The field is in a state of constant flux. This session discusses the relationships of the microbial world to the geosphere from the molecular biology of several perspectives. The session derives from a recent colloquium of the American Academy of Microbiology to define the field and address intellectual, economic, social, and educational issues. | |||||||||||||||
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| Bioconsensus: Bringing Social Choice Theory to Biology Saturday, February 16, 2002 9:00 a.m. - 12:00 noon | ||||||||||||
| Fred S. Roberts, Rutgers University | ||||||||||||
| Consensus methods developed in the context of voting, decision making, and other areas of the social and behavioral sciences are often based on mathematical concepts and tools and increasingly make heavy use of the algorithmic methods of computer science. These consensus methods have begun to have a variety of applications in the biological sciences, originally in taxonomy and evolutionary biology, and more recently in molecular biology. Typically, several alternatives (such as possible taxonomies, alternative phylogenetic trees, alternative molecular sequences, or alternative alignments) are produced using different methods or under different models and then one needs to find a consensus solution. There are, already, several hundred papers in this developing field of "Bioconsensus." In this session, we explore ways to make use of the consensus methods of social choice theory in solving problems of biology, with emphasis on molecular biology. Two talks will develop social choice theory from the social science point of view and provide a synopsis for those not knowledgeable about the field, and will present the beginnings of connections to biology; the remaining talks will give heavy emphasis to the biological applications. | ||||||||||||
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| Mathematical Models for Movement and Aggregation of Cells and Organisms Sunday, February 17, 2002 3:00 p.m. - 6:00 p.m. | |||||||||||||||
| Hans Othmer, University of Minnesota | |||||||||||||||
| Movement is a fundamental process for most biological organisms, and occurs on scales ranging from the single cell level to the population level. Examples of active movement at the cellular level include morphogenesis, wound healing, and angiogenesis, and at the population level, various active and passive dispersal mechanisms operate throughout ecology. The goal may be to find food, to escape danger, to attack intruders, or to find a mate, and to achieve this the individual must detect and process external signals, and transduce them into an internal signal that initiates the appropriate response. Recently there has been a large increase in our understanding of signal detection and transduction in a variety of systems, and new mathematical models that incorporate such microscopic information have been developed. For instance, one aspect of the response to signals is a change in velocity, and in mathematical models of movement this often involves modulating the parameters of stochastic process driving these changes. One theme of this symposium will be how detailed mathematical models that incorporate our current understanding at the single cell level can be developed, and how the analysis of these models can help in understanding how complex spatial and temporal patterns arise. A second theme will be the development of macroscopic descriptions for population-level behavior from these microscopic models. The speakers will focus on a number of examples of movement and its consequences, ranging from motion of individual cells, to aggregation in mathematical models, and the effects on invasion and genetic diversity. | |||||||||||||||
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| The New Computing Friday, February 15, 2002 9:00 a.m. - 12:00 noon | ||||||||||||||||||
| Maureen C. Kelly, Haddonfield, NJ; Rolf M. Sinclair, Chevy Chase, MD | ||||||||||||||||||
| Computing as we know it cannot continue to grow for more than another decade. By 2010 (or not much later) the present exponential growth of such key factors as information storage density and computing speed will reach natural limits. This session explores the inevitable limits on information handling and how new concepts in computing will permit continued development. One entirely new method of computing involves a "quantum computer", which would use all of the states allowed by the quantum principle of superposition to process information. Such a computer, in principle, offers the possibility of an exponential speedup over our present methods. Speakers will consider how new concepts in computing can be realized, how funding opportunities and roadblocks will influence the direction of research and development in computer technology, and what the implications are for long-range planning in industry, universities, and government. A panel discussion will give speakers and panelists an opportunity to interact with the audience and to exchange views on the what lies ahead, including the promises and cautions for computing both on a large scale in the sciences and on the scale of the personal user. | ||||||||||||||||||
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| Waves: Patterns and Turbulence Tuesday, February 19, 2002 8:00 a.m. - 11:00 a.m. | |||||||||||||||
| Walter Craig, McMaster University; Nick Ercolani, University of Arizona | |||||||||||||||
| Patterns, both regular and those with irregularities, are a common feature of physical phenomena that we experience on a daily basis. Pattern forming phenomena occur at virtually all scales; both in nature, from galactic formation, to the motion of waves in the sea surface, to collective behavior of micro-organisms; and in technology, from nanoscale crystal growth arising in fabrication of semiconductor lasers, to far-field optical signals produced by these devices. Mathematicians have long had an interest in phenomena involving pattern formation. Classical approaches to the description of patterns include the derivation of mathematical models, often in the form of partial differential equations and/or nonlinear dynamical systems. The models give a basis from which one can develop numerical experiments, and mathematical analysis of the model equations gives insight into the results of both physical and numerical observations. In the mathematical context of a model one can understand certain features of universality in pattern formation; for instance in the derivation of a model one can come upon closely related systems of equations which would be appropriate to describe physical phenomena on enormously varying scales. | |||||||||||||||
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| Accommodating Interdisciplinarity in the Academic Research Environment Monday, February 18, 2002 9:15 a.m. - 10:45 a.m. | |||||||||
| Edward Derrick, AAAS | |||||||||
| Interdisciplinarity has become a commonly-used phrase in the research environment. High priority issues such as genomics and post-genomics research, biocomplexity, nanomaterials, global climate change and information technology cross the boundaries of traditional disciplines, and require creative approaches from researchers and institutions to address the scientific issues involved. Cutting-edge work often occurs at the boundaries of traditional disciplines. Despite how often the issue arises, it can be hard to support interdisciplinary work. We may be for it in principle but against it in practice. There are barriers inherent in the mechanisms used in funding research and in the organization of the academy. Thus, it also requires creative approaches to support such work. From the researcher's perspective, it may require searching for collaboraters from outside one's normal contacts, and overcoming the psychological barriers to trusting them. From the university's perspective, it may require a rethinking of the mechanisms used to encourage research, and it may also require a rethinking of what is necessary in the preparation of students for research careers. From the funding agency's perspective, it may require aligning traditionally independent units to implement policy that emphasizes results with social value, rather than results with purely scientific value. The symposium examines several arena in which interdisciplinary work is supported and explores these varied perspectives. Mechanisms used by universities to adapt to the changing environment and to encourage interdisciplinary work will be discussed. | |||||||||
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| Best Practices from Research Scientists Who Communicate with the Public Sunday, February 17, 2002 9:00 a.m. - 12:00 noon | |||||||||||||||
| Bruce V. Lewenstein, Cornell University; Ilan Chabay, The New Curiosity Shop | |||||||||||||||
| A new trend in public outreach for science has been to add outreach to the daily activities of working scientific groups. NASA, the National Science Foundation, the Department of Energy, and the National Institutes of Health all provide supplements to scientific grants for PIs who add outreach to their activities. Several national centers, for example in materials research and nanobiotechnology, have built outreach into their programs. Although some of the disciplinary centers have begun to share information, no broad discussion has taken place about how to build on the experiences of the many scientists who now engage in outreach as part of their normal work process. This brings together active research scientists who are engaged in outreach, along with representatives from the disciplinary centers, to get information about best practices, successful innovations, and methods of evaluation. | |||||||||||||||
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| Cultural and Social Diversity |
| The Archaeology of Modern Human Origins Friday, February 15, 2002 9:00 a.m. - 12:00 noon | ||||||||||||||||||||||||||||||
| Geoffrey Clark, Arizona State University | ||||||||||||||||||||||||||||||
| A scientifically adequate explanation of our origins must reconcile proposed explanations for pattern in (1) the archaeology of the Middle-Upper Paleolithic transition, (2) the anatomical transition from archaic to modern humans, and (3) the mtDNA, nDNA, and Y chromosome data. AAAS symposia in 1999 and 2000 emphasized the genetic and fossil evidence. This session focuses on the archaeology. As in other aspects of modern human origins (MHO) research, MHO archaeologists run the gamut between extreme 'replacement' advocates ([H. sapiens] arose only in Africa after 200,000 years ago, emigrated, and replaced earlier hominins throughout the range originally colonized by [H. erectus]), and extreme 'continuity' advocates (people who are skeptical of claims for an Upper Pleistocene migration, who see evidence for biological and behavioural continuity over the transition interval that negates, or renders highly improbable, any kind of categorical biological replacement). Representing a wide range of scholarly perspectives, the participants examine the conceptual frameworks that govern MHO archaeology as they focus on archaeological indicators of Upper Pleistocene behavioural change. Disjunction between biological and cultural indicators of 'modernness' throw into sharp relief problems with the logic of inference in MHO research. Hypothetical relationships between archaic and modern humans in the Levant, west Asia; east, west and south-central Europe, and southeast Africa are examined by looking at migration models, evidence for personal adornment, predator-prey interaction as a function of population-resource imbalances, vectored paleoclimatic change, lithic technology and typology to compare and contrast expectations about pattern generated from the 'replacement' and 'continuity' positions. | ||||||||||||||||||||||||||||||
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| Interstellar Travel and Multi-Generational Space Ships Friday, February 15, 2002 2:30 p.m. - 5:30 p.m. | |||||||||||||||||||||||||||||||||
| Yoji Kondo, NASA Goddard Space Flight Center; John H. Moore, University of Florida | |||||||||||||||||||||||||||||||||
| This symposium examines scientific technologies of the near and far future for interstellar travel that will traverse many light years. Such a trip could take multiple generations -- depending, to some extent, on the propulsion technology. The session investigates the crucial anthropological issues involved in sustaining a group of human beings for an extended period, even over many generations. Such issues as the available living space, sociological and behavioral change, and even the number and types of people who can live together without suffering social disintegration are addressed. The speakers explore what technological, material, and human resources will be needed to settle a new world once reached. This will include skill mixes, personality traits and the genetic considerations (i.e., how to establish an appropriate gene pool) that would be necessary for maintaining a stable and flourishing society. | |||||||||||||||||||||||||||||||||
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| Global Monitoring of World Heritage Sites: Towards a Global Standard Saturday, February 16, 2002 3:00 p.m. - 6:00 p.m. | ||||||||||||||||||
| Janos Jelen, Ministry of Foreign Affairs, Hungary; Diane Evans, NASA Jet Propulsion Laboratory, California Institute of Technolgy | ||||||||||||||||||
| Periodic Report on implementation of the Convention Concerning the Protection of the World Cultural and Natural Heritage is a strategic challenge for a whole range of applied sciences, in particular for remote sensing and GIS, as well as Cultural Resource Management in a truly global communication environment. From 690 sites already inscribed on the World Heritage List 487 are being scrutinized on a regional basis during the first six years of the cycle (2000 to 2005). What happened to the sites after being officially approved to be of "outstanding universal value"? After 30 years of existence the governments of 167 states agreed to look back and report on the status of their most precious sites. Hopefully a new strategic guideline, a standard for Heritage Impact Assessment, will emerge at the end of each 6-year cycle that ought to include recommendations on monitoring and change detection for preservation and development. Space sciences, specially Earth observation programs, including already available remote sensing & GIS applications, could not yet play the role they should to provide the desperately needed CRM tool for governments, municipalities, local communities, investors and developers who are all involved. Education, training and awareness raising for national and local authorities and experts are key to sustainable resource management. Research communities and universities should work in close cooperation with the key stakeholders for the benefit of all. Synergy of CRM, RS & GIS in a global Internet based environment should serve as a model for new site nominations as well as improve disaster-monitoring capacity for site managers and national authorities. | ||||||||||||||||||
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| Biocultural Insights on the Emerging Worldwide Epidemic of Obesity Saturday, February 16, 2002 3:00 p.m. - 6:00 p.m. | ||||||||||||||||||
| Marquisa LaVelle, University of Rhode Island | ||||||||||||||||||
| It is well known that high prevalence rates of obesity are accelerating in industrialized societies, resulting in increased risk for diabetes, cancer, cardiovascular and digestive diseases. Less well understood is the fact that obesity, involving children as well as adults, has recently become a worldwide health problem. This symposium draws attention to the fact that current trends toward excessive fatness is an increasingly global phenomenon, prevalent within nonwestern as well as western societies undergoing rapid socioeconomic change. Recent data on child growth from Latin America, South Africa, Asia, native Australians, the Pacific and the United States, emphasize the emerging risks to future world health. As social scientists working on problems in nutrition and health, our research is designed to provide insights into the biocultural factors that are central to the etiology of obesity in the diverse societies of these world regions. | ||||||||||||||||||
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| Dealing With Global Change |
| Is Extreme Weather Now Better Understood and Predicted? Friday, February 15, 2002 9:00 a.m. - 12:00 noon | ||||||||||||||||||
| Krishna Ramanujan, Science Systems and Applications Inc., NASA Goddard Space Flight Center | ||||||||||||||||||
| Severe weather events happen all over the world and they may occur with a higher frequency with a warming global climate. Like the United States, many nations face tornadoes, hurricanes, El Niño and La Niña-generated extremes and flooding events. Preparation for severe weather is taken on personal, local, and regional scales, but are extreme events predicted with greater accuracy? In this session, scientists will explain how the latest advances in severe weather detection may save lives and property. New satellite data, discoveries and modeling systems have made improvements in forecasting hurricanes, tornadoes, floods, and El Niño-Southern Oscillation (ENSO) events that produce extremes on a global scale. Satellite imagery and data are being used to see hidden lightning not visible to the naked eye, and may provide as much as a 50% increase in severe storm warning lead time. New technology can detect tropical depressions forming before they can be seen. An advanced river forecast service provides pinpointed location information with possibilities on future flooding. Satellites looking at Pacific Ocean rainfall may give clues to developing ENSOs and help nations make advance preparations for ENSO effects. Researchers will explain how and why these findings will contribute to better prediction of weather extremes. | ||||||||||||||||||
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| Not Enough Sea Lions, Too Many Sharks: Global Warming Signal? Saturday, February 16, 2002 8:45 a.m. - 10:15 a.m. | |||||||||
| Vincent Gallucci, University of Washington; Bruce Wright, Environment Alaska | |||||||||
| Ecosystems in the North Pacific are experiencing significant changes, measured by changes in patterns of abundance and presence of many marine animals. These patterns include increases in salmon, decreases in forage fishes, and declines in three pinniped species: Steller sea lions, harbor seals, and northern fur seals. Simultaneously, two shark species: Pacific sleeper and salmon sharks appear to experiencing population explosions. The focus of this symposium is upon pinniped and shark population dynamics and possible predator-prey interactions. A change in the sub-arctic climate regime may be involved in this interaction. It is likely that such interactions are endemic. However, a change in climate may work differentially to the sharks' benefit by intensifying the number of successful predation events and expanding their population sizes. Pinnipeds and sharks are both K-selected species, at the top of the food chain, and living 25-50 years. Therefore, changes in shark or sea lion survival may not be observed for many years. Examination of tropical ecosystem food webs reveals that sharks occupy a wide range of niches, classified according to habitat (reef, oceanic, coastal, etc.) and depth stratification, much of which is temperature mediated. In the Alaskan system, the two shark species are also depth stratified and habitat specific. It is suggested that the regime shift in the North Pacific Ocean is affecting habitats, making the ecosystem less favorable for pinnipeds and more favorable for sharks. This is reflected by increased juvenile survival for the sharks and decreases in pinniped populations. | |||||||||
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| Deciphering the Complex Changes in Global Snow and Ice Saturday, February 16, 2002 3:00 p.m. - 6:00 p.m. |
| David Robinson, Rutgers University; Krishna Ramanujan, Science Systems and Applications Inc., NASA Goddard Space Flight Center |
| The ice caps, snow cover, and glaciers that make up the global cryosphere have shown signs of decline in recent decades. There is a downward trend in sea-ice extent accompanied by sea-ice thinning. Negative snow cover anomalies have dominated both Northern Hemisphere continents since the late 1980s. Small |