Despite the depiction of nature “red in tooth and claw,” cooperation is actually widespread in the animal kingdom. Various types of cooperative behaviors have been documented in everything from ...insects to primates, and in every imaginable ecological scenario. Yet why animals cooperate is still a hotly contested question in literature on evolution and animal behavior. This book examines the history surrounding the study of cooperation, and proceeds to examine the conceptual, theoretical and empirical work on this fascinating subject. Early on, it outlines the four different categories of cooperation -- reciprocal altruism, kinship, group-selected cooperation and byproduct mutualism -- and ties these categories together in a single framework called the Cooperator’s Dilemma. Hundreds of studies on cooperation in insects, fish, birds and mammals are reviewed. cooperation in this wide array of taxa includes, but is not limited to, cooperative hunting, anti-predator behavior, foraging, sexual coalitions, grooming, helpers-at-the nest, territoriality, ‘policing’ behavior and group thermoregulation. Each example outlined is tied back to the theoretical framework developed early on, whenever the data allows. Future experiments designed to further elucidate a particular type of cooperation are provided throughout the book.
Evidence shows acanthosis nigricans is often associated with hyperinsulinemia and may indicate increased risk of type 2 diabetes mellitus. The purpose of this study was to determine the association ...of acanthosis nigricans with type 2 diabetes risk factors and disease in young persons.
We conducted a cross-sectional study in the Research in Outpatient Settings Network, a practice-based research network in southwestern US communities. Participating clinicians (N = 96) collected data on children and young adults aged 7 to 39 years seen during a 2-week sampling period. The main outcomes were the prevalence of acanthosis nigricans, type 2 diabetes risk factors (ethnicity, family history of type 2 diabetes, hypertension, overweight/obesity), type 2 diabetes, and the relationships among these.
Among 1,133 patients sampled, risk factors for type 2 diabetes were common: 69% had a family history of the disease; 3% of children (aged 7 to 19 years) and 12% of adults had hypertension; 43% of children and 73% of adults were overweight or obese; and 80% were members of ethnic minorities. Acanthosis nigricans was found in 17% of children and 21% of adults. Among children and adults alike, the more type 2 diabetes risk factors that were present, the higher the prevalence of acanthosis nigricans (P <.001). The prevalence ratio for type 2 diabetes in patients with acanthosis nigricans was 1.97 (95% confidence interval, 1.18-3.27; P = .01) after controlling for age, body mass index, and the number of type 2 diabetes risk factors. Clinicians reported that the identification of acanthosis nigricans frequently led to discussions about lifestyle modification for decreasing the risk of type 2 diabetes.
Patients with acanthosis nigricans are likely to have multiple risk factors for type 2 diabetes. Acanthosis nigricans may be an independent risk factor for this disease. Detection of acanthosis nigricans may help clinicians more rapidly identify high-risk individuals for diabetes counseling.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Noncommutative geometry provides a powerful tool for regularizing quantum field theories in the form of fuzzy physics. Fuzzy physics maintains symmetries, has no fermion-doubling problem and ...represents topological features efficiently. These lecture notes provide a comprehensive introduction to the field. Starting with the construction of fuzzy spaces, using the concrete examples of the fuzzy sphere and fuzzy complex projective spaces, the book moves on to discuss the technology of star products on noncommutative R2d and on the fuzzy sphere. Scalar, spinor and gauge field theories as well as extended objects such as monopoles and nonlinear sigma modes are treated in considerable detail. A detailed treatment of the regularization of supersymmetry is given using the techniques of fuzzy physics.
Abstract Purpose The increasing attention paid to community-based research highlights the question of whether human research protections focused on the individual are adequate to safeguard ...communities. We conducted a study to explore how community members perceive low-risk health research, the adequacy of human research protection processes, and the ethical conduct of community-based research. Methods Eighteen focus groups were conducted among rural and urban Hispanic and Native American communities in New Mexico using a semistructured guide. Group transcriptions were analyzed using iterative readings and coding, with review of the analytic summary by group members. Results Although participants recognized the value of health research, many also identified several adverse effects of research in their communities, including social (community and individual labeling, stigmatization, and discrimination) and economic (community job losses, increased insurance rates, and loss of community income). A lack of community beneficence was emphasized by participants who spoke of researchers who fail to communicate results adequately or assist with follow-through. Many group members did not believe current human research and data privacy processes were adequate to protect or assist communities. Conclusions Ethical review of community-based health research should apply the Belmont principles to communities. Researchers should adopt additional approaches to community-based research by engaging communities as active partners throughout the research process, focusing on community priorities, and taking extra precautions to assure individual and community privacy. Plans for meaningful dissemination of results to communities should be part of the research design.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The threat of radiological terrorism has recently come to the attention of the international community, as it became clear that terrorist organizations are seeking nuclear and radiological material ...to manufacture and use improvised nuclear devices (IND) and 'dirty bombs', and/or commit acts of sabotage against nuclear power infrastructure. But while nuclear weapons and INDs, still remain relatively secure from terrorist access, radiological material is more readily available in large quantities throughout the world. Also, radiological explosives or other dispersal devices are easier to manufacture and to use. Radiological dispersal devices (RDDs) come in many shapes and sizes; A dirty bomb uses a conventional explosion to scatter radioactive material; Terrorists could launch an attack by placing a container of radioactive material in a public place and an airplane can easily disperse radioactive material as a powder or an aerosol. On a grand scale, a nuclear facility could become an RDD. Intentional damage done to a nuclear power plant or other site could release radiation, contaminating the immediate surroundings or even beyond. RDDs of any kind present a potent and effective terrorist weapon because they threaten to expose civilian populaces to radiation - engendering panic out of proportion to the modest number of casualties likely to result from limited doses of radiation. Coming to terms with the psychological and social dimensions of radiological attacks - areas that are inadequately studied and assessed - is thus a matter of considerable importance for those entrusted with national, and ultimately international, security.
Objective: Ballard scores are commonly used to estimate gestational age (GA). The purpose of this study was to determine the accuracy of the New Ballard Score (NBS) for infants <28 weeks GA by ...accurate menstrual history and to evaluate NBS as an outcome predictor.
Methods: Infants weighing 401 to 1500 g in 12 National Institute of Child Health and Human Development Neonatal Research Network centers had NBS performed before age 48 hours. Accuracy of NBS estimates of GA was assessed for infants with GA determined by accurate menstrual history. In a larger cohort of infants, NBS was included in regression models of the association of NBS and death, poor outcome, and duration of hospital stay.
Results: At each week from 22 to 28 weeks GA by accurate menstrual history, NBS estimates exceeded GA by dates by 1.3 to 3.3 weeks, and estimates varied widely (range of widths of 95% CIs for the observations, 6.8 to 11.9 weeks). NBS did not contribute significantly to regression models of death, poor outcome, or duration of hospital stay.
Conclusions: Inaccuracies in GA determined by the NBS should be considered when treating extremely premature infants, particularly in decisions to forego or administer intensive care. Refinement of GA scoring systems is needed to optimize clinical benefit. (J Pediatr 1999;135:147-52)
Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π+ electroproduction reaction γ*p → nπ+. The results were obtained from scattering of 6-GeV ...longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q2 < 6GeV2. Results were obtained for about 6000 bins in W, Q2, cos(θ*), and Φ*. Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W. Finally, a generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q2, for resonances with masses as high as 2.4 GeV.
The book presents basic structures, concepts and algorithms in the area of multilayer optimizing control of industrial systems, as well as the results of the research that was carried out by the ...authors over the last two decades. The methodologies and control algorithms are thoroughly illustrated by numerous simulation examples. Also, the applications to several case study examples are presented. These include ethylene distillation column, vaporizer pilot scale plant, styrene distillation line consisting of three columns and industrial furnace pilot scale plant. A temporal decomposition is applied to the Integrated Wastewater System case study to derive multilayer dynamic optimizing controller with repetitive robust model predictive control mechanism distributed over the layers operating in different time scales.
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