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91.
Stephen J. Carter Marissa N. Baranauskas Alyce D. Fly 《Obesity (Silver Spring, Md.)》2020,28(7):1176-1177
As the biomedical community races to disentangle the unknowns associated with severe acute respiratory syndrome coronavirus 2, the virus responsible for causing coronavirus disease, the link between diminished immune function and individuals with obesity raises important questions about the possibility for greater viral pathogenicity in this population. Increased adiposity may undermine the pulmonary microenvironment wherein viral pathogenesis and immune cell trafficking could contribute to a maladaptive cycle of local inflammation and secondary injury. A further challenge to those with obesity during the current pandemic may involve vitamin D deficiency or insufficiency. In the interest of personal and public health, we caution decision‐ and policy makers alike not to pin all hope on a proverbial “silver bullet.” Until further breakthroughs emerge, we should remember that modifiable lifestyle factors such as diet and physical activity should not be marginalized. Decades of empirical evidence support both as key factors promoting health and wellness. 相似文献
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Marissa J. Maroni Kimberly M. Capri Nicole L. Arruda Rachel R. Gelineau Hannah V. Deane Holly A. Concepcion 《Chronobiology international》2020,37(6):809-823
ABSTRACT Altered circadian rhythms have negative consequences on health and behavior. Emerging evidence suggests genetics influences the physiological and behavioral responses to circadian disruption. We investigated the effects of a 21 h day (T = 21 cycle), with high-fat diet consumption, on locomotor activity, explorative behaviors, and health in male C57BL/6J and C57BL/6N mice. Mice were exposed to either a T = 24 or T = 21 cycle and given standard rodent chow (RC) or a 60% high-fat diet (HFD) followed by behavioral assays and physiological measures. We uncovered numerous strain differences within the behavioral and physiological assays, mainly that C57BL/6J mice exhibit reduced susceptibility to the obesogenic effects of (HFD) and anxiety-like behavior as well as increased circadian and novelty-induced locomotor activity compared to C57BL/6N mice. There were also substrain-specific differences in behavioral responses to the T = 21 cycle, including exploratory behaviors and circadian locomotor activity. Under the 21-h day, mice consuming RC displayed entrainment, while mice exposed to HFD exhibited a lengthening of activity rhythms. In the open-field and light-dark box, mice exposed to the T = 21 cycle had increased novelty-induced locomotor activity with no further effects of diet, suggesting daylength may affect mood-related behaviors. These results indicate that different circadian cycles impact metabolic and behavioral responses depending on genetic background, and despite circadian entrainment. 相似文献
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Effa P Massougbodji A Ntoumi F Hirsch F Debois H Vicari M Derme A Ndemanga-Kamoune J Nguembo J Impouma B Akué JP Ehouman A Dieye A Kilama W 《Developing world bioethics》2007,7(3):136-142
The involvement of developing countries in international clinical trials is necessary for the development of appropriate medicines for local populations. However, the absence of appropriate structures for ethical review represents a barrier for certain countries. Currently there is very little information available on existing structures dedicated to ethics in western and central Africa. This article briefly describes historical milestones in the development of networks dedicated to capacity building in ethical review in these regions and outlines the major conclusions of two workshops on this issue, which were held in September and October 2002 in Libreville, Gabon, and Paris, France. The workshops were the culmination of collaboration between the African Malaria Network Trust (AMANET) and the Pan African Bioethics Initiative (PABIN). They produced an update on ethics organizations with regard to mission, function, activities, members, and contact people, in eight countries within the regions discussed. As a result of the commitment of mandated delegates, a further prominent outcome followed these workshops: the creation of national structures, where none existed before, dedicated to the ethical review of clinical trials. 相似文献
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Traditional real-time quantitative polymerase chain reaction protocols cannot be used accurately with symbiotic organisms unless the relative contribution of each symbiotic compartment to the total nucleic acid pool is known. A modified 'universal reference gene' protocol was created for reef-building corals and sea anemones, anthozoans that harbour endosymbiotic dinoflagellates belonging to the genus Symbiodinium. Gene expression values are first normalized to an RNA spike and then to a symbiont molecular proxy that represents the number of Symbiodinium cells extracted and present in the RNA. The latter is quantified using the number of genome copies of heat shock protein-70 (HSP70) amplified in the real-time quantitative polymerase chain reaction. Gene expression values are then normalized to the total concentration of RNA to account for differences in the amount of live tissue extracted among experimental treatments and replicates. The molecular quantification of symbiont cells and effect of increasing symbiont contributions to the nucleic acid pool on gene expression were tested in vivo using differentially infected sea anemones Aiptasia pulchella. This protocol has broad application to researchers who seek to measure gene expression in mixed organism assemblages. 相似文献
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Carbon and Nitrogen Cycling in Soils from Acidic and Nonacidic Tundra with Different Glacial Histories in Northern Alaska 总被引:1,自引:1,他引:1
Moist acidic and nonacidic tundra are two of the most common vegetation types of the tundra in the northern foothills of the
Brooks Range, Alaska, and they differ considerably in vegetation, soil nutrient availability, and soil pH. Both occur on mesic,
gentle slopes, but acidic tundra is more common on older glacial surfaces whereas nonacidic tundra is more common on younger
surfaces. Although much prior research has focused on moist acidic tundra, nonacidic tundra is still relatively unstudied.
We compared rates of soil carbon (C) and nitrogen (N) cycling and their response to warming and changes in moisture in moist
acidic tundra on Itkillik I glacial drift (50,000–120,000 years old, pH = 3–4) and moist nonacidic tundra on Itkillik II glacial
drift (11,500–60,000 year old, pH = 6–7). We hypothesized that rates of soil C and N cycling would be faster at the nonacidic
site because it has a more favorable pH for microbial activity and higher-quality organic matter inputs arising from its greater
herbaceous plant production relative to the acidic site. However, in contrast to our hypothesis, in situ soil respiration,
as well as respiration, dissolved organic C production, and net N mineralization in laboratory incubations, was greater for
soils from the acidic site. Nevertheless, the sites responded similarly to manipulations of temperature and moisture, exhibiting
exponential increases in respiration with warming between 4°C and 15°C but surprisingly little sensitivity to changes in moisture
between 300% and 700%. Slower soil organic matter decomposition at the nonacidic site likely results from the stabilization
of soil organic matter by high concentrations of calcium.
Received 27 August 2001; accepted 3 April 2002. 相似文献
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Marissa McClure Patricia Tarr Christine Marmé Thompson Angela Eckhoff 《Arts Education Policy Review》2017,118(3):154-163
ABSTRACTThis article reflects the collective voices of four early childhood visual arts educators, each of whom is a member of the Early Childhood Art Educators (ECAE) Issues Group of the National Arts Educators Association. The authors frame the article around the ECAE position statement, Art: Essential for Early Learning (2016), which focuses on the central role of art interactions among young children, educators, environments, and materials. The authors describe eight principles that underlie the statement from philosophical viewpoints, and provide practical examples of the principles in action. Amid a varied policy landscape for visual art in early childhood, the authors assert that children need organized, materials-rich environments that invite discovery, interaction, sensory and kinesthetic exploration, wonder, inquiry, and imagination in relationship with responsive educators who value young children's diverse abilities, interests, questions, ideas, and cultural experiences. The authors explore issues and possibilities resulting when educators work to bring visual arts fully and dynamically into the lives of young children in diverse education and care spaces. In closing, the authors explore the realities of visual arts policies in the early childhood education and art education fields while emphasizing the critical need for supportive pedagogical practices in all early childhood classrooms. 相似文献
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Delaney JR Sutphin GL Dulken B Sim S Kim JR Robison B Schleit J Murakami CJ Carr D An EH Choi E Chou A Fletcher M Jelic M Liu B Lockshon D Moller RM Pak DN Peng Q Peng ZJ Pham KM Sage M Solanky A Steffen KK Tsuchiya M Tsuchiyama S Johnson S Raabe C Suh Y Zhou Z Liu X Kennedy BK Kaeberlein M 《Aging cell》2011,10(6):1089-1091
Activation of Sir2 orthologs is proposed to increase lifespan downstream of dietary restriction. Here, we describe an examination of the effect of 32 different lifespan-extending mutations and four methods of DR on replicative lifespan (RLS) in the short-lived sir2Δ yeast strain. In every case, deletion of SIR2 prevented RLS extension; however, RLS extension was restored when both SIR2 and FOB1 were deleted in several cases, demonstrating that SIR2 is not directly required for RLS extension. These findings indicate that suppression of the sir2Δ lifespan defect is a rare phenotype among longevity interventions and suggest that sir2Δ cells senesce rapidly by a mechanism distinct from that of wild-type cells. They also demonstrate that failure to observe lifespan extension in a short-lived background, such as cells or animals lacking sirtuins, should be interpreted with caution. 相似文献
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Ramsier MA Cunningham AJ Moritz GL Finneran JJ Williams CV Ong PS Gursky-Doyen SL Dominy NJ 《Biology letters》2012,8(4):508-511
Few mammals-cetaceans, domestic cats and select bats and rodents-can send and receive vocal signals contained within the ultrasonic domain, or pure ultrasound (greater than 20 kHz). Here, we use the auditory brainstem response (ABR) method to demonstrate that a species of nocturnal primate, the Philippine tarsier (Tarsius syrichta), has a high-frequency limit of auditory sensitivity of ca 91 kHz. We also recorded a vocalization with a dominant frequency of 70 kHz. Such values are among the highest recorded for any terrestrial mammal, and a relatively extreme example of ultrasonic communication. For Philippine tarsiers, ultrasonic vocalizations might represent a private channel of communication that subverts detection by predators, prey and competitors, enhances energetic efficiency, or improves detection against low-frequency background noise. 相似文献