Reprodution of Dairy Cattle

PDF pages:

AGRICULTURAL AND FOOD POLICY ISSUES AND THE LEGISLATIVE PROCESS

Agricultural and Food Policy,

Natural Scene Statistics Account for the Representation of Scene Categories in Human Visual Cortex

SummaryDuring natural vision, humans categorize the scenes they encounter: an office, the beach, and so on. These categories are informed by knowledge of the way that objects co-occur in natural scenes. How does the human brain aggregate information about objects to represent scene categories? To explore this issue, we used statistical learning methods to learn categories that objectively capture the co-occurrence statistics of objects in a large collection of natural scenes. Using the learned categories, we modeled fMRI brain signals evoked in human subjects when viewing images of scenes. We find that evoked activity across much of anterior visual cortex is explained by the learned categories. Furthermore, a decoder based on these scene categories accurately predicts the categories and objects comprising novel scenes from brain activity evoked by those scenes. These results suggest that the human brain represents scene categories that capture the co-occurrence statistics of objects in the world

Survival and Recruitment of Gray Wolf Pups Before and after Harvest

Knowledge about recruitment in a population can be critical when making conservation decisions, particularly for harvested species. Harvest can affect population demography in complex ways and this may be particularly true for species whose successful reproduction is linked with complex social dynamics. We used noninvasive genetic sampling and a natural experiment to estimate recruitment in gray wolves (Canis lupus) before and after harvest in the northern Rocky Mountains, Idaho USA (2008-2013). We hypothesized that recruitment would decline after hunting and trapping began and that the decline in recruitment would be attributable to the harvest of pups and not subtler mechanisms associated with group dynamics and reduced reproductive success. We collected fecal samples from wolves in 10 packs for 6 consecutive years, extracted DNA, and genotyped 154 individual pups across 18 microsatellite loci. Population harvest rates averaged 23.8% (SD = 9.2). Our hypothesis that recruitment would decline was supported; survival from 3 – 15 months of age decreased from 0.60 (95% CI: 0.48-0.72) without harvest to 0.38 (95% CI: 0.28-0.48) with harvest and recruitment declined from 3.2 (95% CI: 2.1-4.3) to 1.6 (95% CI: 1.1-2.1) pups per pack after harvest was initiated. We attributed just 18-38% of pup mortality directly to harvest and suggest that there are indirect effects of harvest on recruitment that may be associated with changes in group size and structure. Models that do not include both direct and indirect effects of harvest on recruitment may underestimate the potential impact of harvest on population growth in social species

Social Support and Survival Strategies of Older African American Grandmother Caregivers

The effects of caring for grandchildren on grandparents’ emotional and physical well-being have become a significant area of focus in behavioral and medical research. Research suggests that African American grandmothers may experience increased mental and physical health challenges due to their caregiving stressors. To buffer the adverse influence of stress, caregivers often rely on informal social support from family and/or community members. In this study we explored older, African American caregivers’ management of their emotional well-being within the context and circumstances of available to minimal social support from family and community. During an 18-month period, seven caregiving grandmothers participated in three face-to-face, audiotaped, semi-structured interviews; eco-map and genogram data was included to understand the contextual complexities of caregivers’ social support and their strategies for survival. Using constant comparative analysis, six interrelated themes revealed grandmothers operated along a continuum of reliable to unreliable social support. In the context of these varying ranges of social support, four sub-themes depicting their survival strategies were identified: being strong, self-sacrificing, receiving help and self-compassion. Utilization of each survival strategy was dependent on grandmothers’ perception of where they fell on the continuum of reliable to unreliable social support. Grandmothers who engaged in being strong and self-sacrificing engaged in stress-related health behaviors, such as emotional eating, smoking nicotine, disruptive sleep patterns and postponement of self-care. We offer specific practice recommendations for addressing the emotional and physical health needs of grandmother caregivers

Changes in the Carbon and Energy Balance of the Sagebrush Steppe Ecosystem of the Pacific Northwest - White Paper

We propose a multi-agency study to understand the impacts of land-use change on the carbon and energy balance of the Pacific Northwest. By integrating data for the carbon and energy fluxes across different scales within each land-use type, we will develop more accurate input parameters for the regional climate models. The product of this study will address two priorities recommended by the National Academy of Sciences; 1) reduce uncertainties in climate change projections and 2) provide a more definitive evaluation of long-term changes

Auditory sensitivity in aquatic animals

© 2016 Acoustical Society of America. A critical concern with respect to marine animal acoustics is the issue of hearing "sensitivity," as it is widely used as a criterion for the onset of noise-induced effects. Important aspects of research on sensitivity to sound by marine animals include: uncertainties regarding how well these species detect and respond to different sounds; the masking effects of man-made sounds on the detection of biologically important sounds; the question how internal state, motivation, context, and previous experience affect their behavioral responses; and the long-term and cumulative effects of sound exposure. If we are to better understand the sensitivity of marine animals to sound we must concentrate research on these questions. In order to assess population level and ecological community impacts new approaches can possibly be adopted from other disciplines and applied to marine fauna

Academy of Dental Materials guidance-Resin composites: Part I-Mechanical properties

Objective. The objective of this project, which was initiated from the Academy of Dental Materials, was to review and critically appraise methods to determine fracture, deformation and wear resistance of dental resin composites, in an attempt to provide guidance for investigators endeavoring to study these properties for these materials. Methods. Test methods have been ranked in the priority of the specific property being tested, as well as of the specific test methods for evaluating that property. Focus was placed on the tests that are considered to be of the highest priority in terms of being the most useful, applicable, supported by the literature, and which show a correlation with clinical findings. Others are mentioned briefly for the purpose of being inclusive. When a standard test method exists, including those used in other fields, these have been identified in the beginning of each section. Also, some examples from the resin composite literature are included for each test method. Results. The properties for evaluating resin composites were ranked in the priority of measurement as following: (1) Strength, Elastic Modulus, Fracture toughness, Fatigue, Indentation Hardness, Wear abrasion (third body) and Wear attrition (contact/two body), (2) Toughness, Edge strength (chipping) and (3) Wear determined by toothbrush. Significance. The following guidance is meant to aid the researcher in choosing the proper method to assess key properties of dental resin composites with regard to their fracture, deformation and wear resistance

Origin of micro-scale heterogeneity in polymerisation of photo-activated resin composites

Photo-activated resin composites are widely used in industry and medicine. Despite extensive chemical characterisation, the micro-scale pattern of resin matrix reactive group conversion between filler particles is not fully understood. Using an advanced synchrotron-based wide-field IR imaging system and state-of-the-art Mie scattering corrections, we observe how the presence of monodispersed silica filler particles in a methacrylate based resin reduces local conversion and chemical bond strain in the polymer phase. Here we show that heterogeneity originates from a lower converted and reduced bond strain boundary layer encapsulating each particle, whilst at larger inter-particulate distances light attenuation and monomer mobility predominantly influence conversion. Increased conversion corresponds to greater bond strain, however, strain generation appears sensitive to differences in conversion rate and implies subtle distinctions in the final polymer structure. We expect these findings to inform current predictive models of mechanical behaviour in polymer-composite materials, particularly at the resin-filler interface