5,554 research outputs found

    Partons and Jets at the LHC

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    I review some issues related to short distance QCD and its relation to the experimental program of the Large Hadron Collider (LHC) now under construction in Geneva.Comment: Talk at the conference QCD2002 at IIT Kanpur, India, November 2002. Ten pages with 12 figure

    Consistent within-individual plasticity is sufficient to explain temperature responses in red deer reproductive traits

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    Warming global temperatures are affecting a range of aspects of wild populations, but the exact mechanisms driving associations between temperature and phenotypic traits may be difficult to identify. Here, we use a 36-year data-set on a wild population of red deer to investigate the causes of associations between temperature and two important components of female reproduction: timing of breeding and offspring size. By separating within- versus between-individual associations with temperature for each trait, we show that within-individual phenotypic plasticity (changes within a female’s lifetime) was entirely sufficient to generate the observed population-level association with temperature at key times of year. However, despite apparently adequate statistical power, we found no evidence of any variation between females in their responses (i.e. no ‘IxE’ interactions). Our results suggest that female deer show plasticity in reproductive traits in response to temperatures in the year leading up to calving, and that this response is consistent across individuals, implying no potential for either selection or heritability of plasticity. We estimate that the plastic response to rising temperatures explained 24% of the observed advance in mean calving date over the study period. We highlight the need for comparable analyses of other systems to determine the contribution of within-individual plasticity to population-level responses to climate change

    Buffalo Reading List

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    This reading list gathers together literature focused on buffalo (also known as bison) to support ongoing efforts to restore this iconic species to its keystone cultural and ecological role. The books and articles compiled here are grounded in a wide range of academic disciplines and approaches, representing many distinct ways of thinking about buffalo within the realm of Western sciences. This is not intended to be an exhaustive account of what is known about buffalo, much of which is held in Indigenous knowledge systems and communities. This academic list is designed as a resource for those working towards buffalo restoration, including conservation practitioners, researchers, parks and government officials, and Tribal communities. It is divided into categories according to either discipline or thematic focus, each containing a subset of pertinent literature. Topics include the paleobiology of bison, histories of buffalo loss, relationships between Indigenous Peoples and buffalo, buffalo restoration and reintroduction, buffalo ecology, buffalo and climate change, governance and human dimensions of buffalo, bison and cattle, bison as livestock, and the genetics of bison. This list is intended as a living document to grow with the increasingly rich scholarship on buffalo, and will be updated regularly

    Parton Distributions Working Group

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    The main focus of this working group was to investigate the different issues associated with the development of quantitative tools to estimate parton distribution functions uncertainties. In the conclusion, we introduce a "Manifesto" that describes an optimal method for reporting data.Comment: Report of the Parton Distributions Working Group of the 'QCD and Weak Boson Physics workshop in preparation for Run II at the Fermilab Tevatron'. Co-Conveners: L. de Barbaro, S.A. Keller, S. Kuhlmann, H. Schellman, and W.-K. Tun

    The MSSM prediction for W+/- H-/+ production by gluon fusion

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    We discuss the associated W+/- H-/+ production in p p collision for the Large Hadron Collider. A complete one-loop calculation of the loop-induced subprocess g g -> W+/- H-/+ is presented in the framework of the Minimal Supersymmetric Standard Model (MSSM), and the possible enhancement of the hadronic cross section is investigated under the constraint from the squark direct-search results and the low-energy precision data. Because of the large destructive interplay in the quark-loop contributions between triangle-type and box-type diagrams, the squark-loop contributions turn out to be comparable with the quark-loop ones. In particular, the hadronic cross section via gluon fusion can be extensively enhanced by squark-pair threshold effects in the box-type diagrams, so that it can be as large as the hadronic cross section via the b b-bar -> W+/- H-/+ subprocess which appears at tree level.Comment: 35 pages, 7 figures, version to appear in Physical Review

    Mesons with Beauty and Charm: Spectroscopy

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    Applying knowledge of the interaction between heavy quarks derived from the study of ccc\overline{c} and bbb\overline{b} bound states, we calculate the spectrum of cbc\overline{b} mesons. We compute transition rates for the electromagnetic and hadronic cascades that lead from excited states to the 1S0^1\text{S}_0 ground state, and briefly consider the prospects for experimental observation of the spectrum.Comment: 32 pages + 2 uuencoded PostScript figures Fermilab-Pub-94/032-

    Airborne Laser/GPS Mapping of Assateague National Seashore Beach

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    Results are presented from topographic surveys of the Assateague Island National Seashore using recently developed Airborne Topographic Mapper (ATM) and kinematic Global Positioning System (GPS) technology. In November, 1995, and again in May, 1996, the NASA Arctic Ice Mapping (AIM) group from the Goddard Space Flight Center's Wallops Flight Facility conducted the topographic surveys as a part of technology enhancement activities prior to conducting missions to measure the elevation of extensive sections of the Greenland Ice Sheet as part of NASA's Global Climate Change program. Differences between overlapping portions of both surveys are compared for quality control. An independent assessment of the accuracy of the ATM survey is provided by comparison to surface surveys which were conducted using standard techniques. The goal of these projects is to mdke these measurements to an accuracy of +/- 10 cm. Differences between the fall 1995 and 1996 surveys provides an assessment of net changes in the beach morphology over an annual cycle

    The Perfect Family: Decision Making in Biparental Care

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    Background Previous theoretical work on parental decisions in biparental care has emphasized the role of the conflict between evolutionary interests of parents in these decisions. A prominent prediction from this work is that parents should compensate for decreases in each other\u27s effort, but only partially so. However, experimental tests that manipulate parents and measure their responses fail to confirm this prediction. At the same time, the process of parental decision making has remained unexplored theoretically. We develop a model to address the discrepancy between experiments and the theoretical prediction, and explore how assuming different decision making processes changes the prediction from the theory. Model Description We assume that parents make decisions in behavioral time. They have a fixed time budget, and allocate it between two parental tasks: provisioning the offspring and defending the nest. The proximate determinant of the allocation decisions are parents\u27 behavioral objectives. We assume both parents aim to maximize the offspring production from the nest. Experimental manipulations change the shape of the nest production function. We consider two different scenarios for how parents make decisions: one where parents communicate with each other and act together (the perfect family), and one where they do not communicate, and act independently (the almost perfect family). Conclusions/Significance The perfect family model is able to generate all the types of responses seen in experimental studies. The kind of response predicted depends on the nest production function, i.e. how parents\u27 allocations affect offspring production, and the type of experimental manipulation. In particular, we find that complementarity of parents\u27 allocations promotes matching responses. In contrast, the relative responses do not depend on the type of manipulation in the almost perfect family model. These results highlight the importance of the interaction between nest production function and how parents make decisions, factors that have largely been overlooked in previous models

    Cohort profile: prescriptions dispensed in the community linked to the national cancer registry in England.

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    PURPOSE: The linked prescriptions cancer registry data resource was set up to extend our understanding of the pathway for patients with cancer past secondary care into the community, to ultimately improve patient outcomes. PARTICIPANTS: The linked prescriptions cancer registry data resource is currently available for April to July 2015, for all patients diagnosed with cancer in England with a dispensed prescription in that time frame.The dispensed prescriptions data are collected by National Health Service (NHS) Prescription Services, and the cancer registry data are processed by Public Health England. All data are routine healthcare data, used for secondary purposes, linked using a pseudonymised version of the patient's NHS number and date of birth.Detailed demographic and clinical information on the type of cancer diagnosed and treatment is collected by the cancer registry. The dispensed prescriptions data contain basic demographic information, geography measures of the dispensed prescription, drug information (quantity, strength and presentation), cost of the drug and the date that the dispensed prescription was submitted to NHS Business Services Authority. FINDINGS TO DATE: Findings include a study of end of life prescribing in the community among patients with cancer, an investigation of repeat prescriptions to derive measures of prior morbidity status in patients with cancer and studies of prescription activity surrounding the date of cancer diagnosis. FUTURE PLANS: This English linked resource could be used for cancer epidemiological studies of diagnostic pathways, health outcomes and inequalities; to establish primary care comorbidity indices and for guideline concordance studies of treatment, particularly hormonal therapy, as a major treatment modality for breast and prostate cancer which has been largely delivered in the community setting for a number of years

    Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

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    Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity
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