2,460 research outputs found
Topology, Locality, and Aharonov-Bohm Effect with Neutrons
Recent neutron interferometry experiments have been interpreted as
demonstrating a new topological phenomenon similar in principle to the usual
Aharonov-Bohm (AB) effect, but with the neutron's magnetic moment replacing the
electron's charge. We show that the new phenomenon, called Scalar AB (SAB)
effect, follows from an ordinary local interaction, contrary to the usual AB
effect, and we argue that the SAB effect is not a topological effect by any
useful definition. We find that SAB actually measures an apparently novel spin
autocorrelation whose operator equations of motion contain the local torque in
the magnetic field. We note that the same remarks apply to the Aharonov-Casher
effect.Comment: 9 page
Aging and decision making: a comparison between neurologically healthy elderly and young individuals
We report the results of experiments on economic decisions with two populations, one of healthy elderly individuals (average age 82) and one of younger students (average age 20). We examine confidence, decisions under uncertainty, differences between willingness to pay and willingness to accept and the theory of mind (strategic thinking). Our findings indicate that the older adults’ decision behavior is similar to that of young adults, contrary to the notion that economic decision making is impaired with age. Moreover, some of the demonstrated decision behaviors suggest that the elderly individuals are less biased than the younger individuals
Early Hearing-Impairment Results in Crossmodal Reorganization of Ferret Core Auditory Cortex
Numerous investigations of cortical crossmodal plasticity, most often in congenital or early-deaf subjects, have indicated that secondary auditory cortical areas reorganize to exhibit visual responsiveness while the core auditory regions are largely spared. However, a recent study of adult-deafened ferrets demonstrated that core auditory cortex was reorganized by the somatosensory modality. Because adult animals have matured beyond their critical period of sensory development and plasticity, it was not known if adult-deafening and early-deafening would generate the same crossmodal results. The present study used young, ototoxically-lesioned ferrets () that, after maturation (avg. = 173 days old), showed significant hearing deficits (avg. threshold = 72 dB SPL). Recordings from single-units () in core auditory cortex showed that 72% were activated by somatosensory stimulation (compared to 1% in hearing controls). In addition, tracer injection into early hearing-impaired core auditory cortex labeled essentially the same auditory cortical and thalamic projection sources as seen for injections in the hearing controls, indicating that the functional reorganization was not the result of new or latent projections to the cortex. These data, along with similar observations from adult-deafened and adult hearing-impaired animals, support the recently proposed brainstem theory for crossmodal plasticity induced by hearing loss
Time Distortions in Mind
Time Distortions in Mind brings together current research on temporal processing in clinical populations to elucidate the interdependence between perturbations in timing and disturbances in the mind and brain. For the student, the scientist, and the stepping-stone for further research
Race and Sex Differences in Correlates of Systolic Blood Pressure in Community-Dwelling Older Adults
Objectives: To describe correlates of measured systolic blood pressure (SBP) among community-dwelling older African American and White Medicare beneficiaries.
Methods: Participants completed an in-home assessment and factors significantly correlated with SBP were tested using multivariable models.
Results: Among the 958 participants (mean age= 75.3 [SD = 6.8]; 49% African American; 49% female; 52% rural) African Americans were more often diagnosed with hypertension, more likely on anti-hypertensives, and on more anti-hypertensive medications. SBP was 2.7 mmHg higher in African Americans than Whites (p=.03). SBP was higher in women than men. Multivariable models revealed differences in the factors associated with SBP by race/sex specific groups. Having a history of smoking and reports of being relaxed and free of tension were associated with higher SBP among African American men.
Discussion: Although more likely prescribed anti-hypertensives, mean SBP was higher for older African Americans than Whites. Results support the hypothesis that behavioral and psychosocial factors are more important correlates of SBP levels among older African Americans than among Whites
Sociomedical Perspectives on Patient Care
Social change has placed new demands on the practice of medicine, altering almost every aspect of patient care relationships. Just as medicine was encouraged to embrace the biological sciences some 100 years ago, recent directives indicate the importance of the social sciences in understanding biomedical practice. Humanistic challenges call for changes in curative and technological imperatives. In this book, social scientists contribute to such challenges by using social evidence to indicate appropriate new goals for health care in a changing environment.
This book was designed to stimulate and challenge all those concerned with the human interactions that constitute medical practice. To encompass a wide range of topics, the authors include researchers; practicing physicians from the specialties of family, general, geriatric, pediatric, and oncological medicine; social and behavioral scientists; and public health representatives. Cutting across disciplinary boundaries, they explore the ethical, economic, and social aspects of patient care.
These essays draw on past studies of the patient-doctor relationship and generate new and important questions. They address social behavior in patient care as a way to approach theoretical issues pertinent to the social and medical sciences. The authors also use social variables to study patient care and suggest new areas of sociomedical inquiry and new approaches to medical practice, education, and research.
Its cross-disciplinary approach and jargon-free writing make this book an important and accessible tool for physician, scholar, and student.
Jeffrey Michael Clair is assistant professor of sociology and medicine and director of the Medical Sociology Program at the University of Alabama at Birmingham.
Richard M. Allman is associate professor of medicine and director of the University Center for Aging at the University of Alabama at Birmingham.
Provides many unique and revealing perspectives on the doctor-patient relationship. —Journal of the American Medical Associationhttps://uknowledge.uky.edu/upk_medicine_and_health_sciences/1011/thumbnail.jp
A framework for interpreting functional networks in schizophrenia
Some promising genetic correlates of schizophrenia have emerged in recent years but none explain more than a small fraction of cases. The challenge of our time is to characterize the neuronal networks underlying schizophrenia and other neuropsychiatric illnesses. Early models of schizophrenia have been limited by the ability to readily evaluate large-scale networks in living patients. With the development of resting state and advanced structural magnetic resonance imaging, it has become possible to do this. While we are at an early stage, a number of models of intrinsic brain networks have been developed to account for schizophrenia and other neuropsychiatric disorders. This paper reviews the recent voxel-based morphometry (VBM), diffusion tensor imaging (DTI), and resting functional magnetic resonance imaging literature in light of the proposed networks underlying these disorders. It is suggested that there is support for recently proposed models that suggest a pivotal role for the salience network. However, the interactions of this network with the default mode network and executive control networks are not sufficient to explain schizophrenic symptoms or distinguish them from other neuropsychiatric disorders. Alternatively, it is proposed that schizophrenia arises from a uniquely human brain network associated with directed effort including the dorsal anterior and posterior cingulate cortex (PCC), auditory cortex, and hippocampus while mood disorders arise from a different brain network associated with emotional encoding including the ventral anterior cingulate cortex (ACC), orbital frontal cortex, and amygdala. Both interact with the dorsolateral prefrontal cortex and a representation network including the frontal and temporal poles and the fronto-insular cortex, allowing the representation of the thoughts, feelings, and actions of self and others across time
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