1,826 research outputs found
Nuclear dependence asymmetries in direct photon production
We study the nuclear dependences of high- jet cross sections in one
photon and one jet production in proton-nucleus collisions. We find that there
exist asymmetries between the outgoing jets and photons. A convincing reason
responsible for those asymmetries are demonstrated in perturbative QCD.
Significant nuclear enhancements are also found in the inclusive jet cross
sections.Comment: 9 pages, LaTeX, 5 ps-figure
Trying not to try: The paradox of intentionality in jazz improvisation and its implications for organizational scholarship
Organizational scholars have long been interested in how jazz musicians manage tensions between structure and freedom, plans and action, and familiarity and novelty. Although improvisation has been conceptualized as a way of managing such paradoxes, the process of improvisation itself contains paradoxes. In this essay, we return to jazz improvisation to identify a new paradox of interest to organizational scholars: the paradox of intentionality. To improvise creatively, jazz musicians report that they must ātry not to try,ā or risk undermining the very spontaneity that is prized in jazz. Jazz improvisers must therefore control their ability to relinquish deliberate control of their actions. To accomplish this, they engage in three interdependent practices. Jazz musicians intentionally surrender their sense of active control (āletting goā) while creating a passive externalized role for this sense of active control (using a āthird earā). Letting go allows new and unexpected ideas to emerge, while the metaphorical third ear can identify promising ideas or problematic execution and, in doing so, re-engage active agency (āgrabbing holdā). Examining the practices within creative improvisation reveals the complexity of the lived experience of the paradox, which we argue suggests further integration among organizational research on improvisation, creativity, and paradox
Climate Change Impacts on Hydro-generation and Land Suitability for Agriculture in Least Developed Countries of the Greater Mekong Sub-region
The main objective of this report is to understand the climate induced changes in precipitation, water inflow, and land-suitability for food and bioenergy production in the case study countries (Cambodia, Laos and Myanmar) where electricity system is heavily dependent on hydro and the economy of the rural population heavily depends on the agriculture. Rural agrarian communities are highly vulnerable to climate change as their income heavily depends on agriculture and has very limited access to electricity (Morton 2007). Access to electricity and climate resilience in the agriculture sector are expected to facilitate enhanced economic activities, secure jobs, and income generated by the sector and its supply chain for rural communities. Further, increased development, driven by access to clean energy and employment, is also key to achieve several SDGs such as health and wellbeing, education, poverty alleviation, reducing inequality and promoting gender equality. This report quantifies and analyses the impacts of climate change on water availability and land suitability for key crops in three least developed countries in the Greater Mekong Sub-region, namely, Cambodia, Laos and Myanmar. We use different databases (CMIP5 for climate and ISIMIP for hydropower data) as well as a modelling tool (land suitability model) to conduct these analyses
Expansion of the Parkinson disease-associated SNCA-Rep1 allele upregulates human alpha-synuclein in transgenic mouse brain.
Alpha-synuclein (SNCA) gene has been implicated in the development of rare forms of familial Parkinson disease (PD). Recently, it was shown that an increase in SNCA copy numbers leads to elevated levels of wild-type SNCA-mRNA and protein and is sufficient to cause early-onset, familial PD. A critical question concerning the molecular pathogenesis of PD is what contributory role, if any, is played by the SNCA gene in sporadic PD. The expansion of SNCA-Rep1, an upstream, polymorphic microsatellite of the SNCA gene, is associated with elevated risk for sporadic PD. However, whether SNCA-Rep1 is the causal variant and the underlying mechanism with which its effect is mediated by remained elusive. We report here the effects of three distinct SNCA-Rep1 variants in the brains of 72 mice transgenic for the entire human SNCA locus. Human SNCA-mRNA and protein levels were increased 1.7- and 1.25-fold, respectively, in homozygotes for the expanded, PD risk-conferring allele compared with homozygotes for the shorter, protective allele. When adjusting for the total SNCA-protein concentration (endogenous mouse and transgenic human) expressed in each brain, the expanded risk allele contributed 2.6-fold more to the SNCA steady-state than the shorter allele. Furthermore, targeted deletion of Rep1 resulted in the lowest human SNCA-mRNA and protein concentrations in murine brain. In contrast, the Rep1 effect was not observed in blood lysates from the same mice. These results demonstrate that Rep1 regulates human SNCA expression by enhancing its transcription in the adult nervous system and suggest that homozygosity for the expanded Rep1 allele may mimic locus multiplication, thereby elevating PD risk
Heavy quarkonium 2S states in light-front quark model
We study the charmonium 2S states and , and the bottomonium
2S states and , using the light-front quark model and the
2S state wave function of harmonic oscillator as the approximation of the 2S
quarkonium wave function. The decay constants, transition form factors and
masses of these mesons are calculated and compared with experimental data.
Predictions of quantities such as Br are made. The
2S wave function may help us learn more about the structure of these heavy
quarkonia.Comment: 5 latex pages, final version for journal publicatio
Meningococcal genetic variation mechanisms viewed through comparative analysis of Serogroup C strain FAM18
Copyright @ 2007 Public Library of ScienceThe bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and meningitis, making the bacterium a major cause of morbidity and mortality in both the developed and developing world. The species is known to be diverse in many ways, as a product of its natural transformability and of a range of recombination and mutation-based systems. Previous work on pathogenic Neisseria has identified several mechanisms for the generation of diversity of surface structures, including phase variation based on slippage-like mechanisms and sequence conversion of expressed genes using information from silent loci. Comparison of the genome sequences of two N. meningitidis strains, serogroup B MC58 and serogroup A Z2491, suggested further mechanisms of variation, including C-terminal exchange in specific genes and enhanced localised recombination and variation related to repeat arrays. We have sequenced the genome of N. meningitidis strain FAM18, a representative of the ST-11/ET-37 complex, providing the first genome sequence for the disease-causing serogroup C meningococci; it has 1,976 predicted genes, of which 60 do not have orthologues in the previously sequenced serogroup A or B strains. Through genome comparison with Z2491 and MC58 we have further characterised specific mechanisms of genetic variation in N. meningitidis, describing specialised loci for generation of cell surface protein variants and measuring the association between noncoding repeat arrays and sequence variation in flanking genes. Here we provide a detailed view of novel genetic diversification mechanisms in N. meningitidis. Our analysis provides evidence for the hypothesis that the noncoding repeat arrays in neisserial genomes (neisserial intergenic mosaic elements) provide a crucial mechanism for the generation of surface antigen variants. Such variation will have an impact on the interaction with the host tissues, and understanding these mechanisms is important to aid our understanding of the intimate and complex relationship between the human nasopharynx and the meningococcus.This work was supported by the Wellcome Trust through the Beowulf Genomics Initiative
Unrelated Helpers in a Primitively Eusocial Wasp: Is Helping Tailored Towards Direct Fitness?
The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests
Primary psoas abscess extending to thigh adductors: case report
<p>Abstract</p> <p>Background</p> <p>Psoas abscess is a rare condition consisting of pyomyositis of the psoas. The worldwide incidence was 12 cases per 100,000 per year in 1992, but the current incidence is unknown. Psoas abscess can descend along the psoas sheath and reach the inner upper third of the thigh, but only infrequently does it penetrate the sheath and involve the thigh adductors. Because of insidious clinical presentation, the diagnosis of psoas abscess is a challenge. Delayed diagnosis can result in poor prognosis.</p> <p>Case presentation</p> <p>A 45-year-old male with no significant past medical history presented with pain in the left thigh, and limitation of movement at the left hip and knee joint for one month. Ultrasound, CT, and MRI revealed a liquid mass in the left psoas. Percutaneous drainage of this mass yielded 300 ml pus from the psoas. After surgery, the patient reported relief of pain; however, ten days after removal of the drainage tube, the patient complained of persistent pain in his left thigh. CT revealed that the psoas abscess had extended inferiorly, and involved the entire set of adductors of the left thigh. Open surgical drainage was performed at the flank and at the thigh, yielding 350 ml of pus from the thigh. After open drainage and adequate antibiotic therapy, the patient made a good recovery. Follow-up CT confirmed complete resolution of the abscess.</p> <p>Conclusions</p> <p>Large psoas abscess can penetrate the psoas sheath, and descend to thigh adductors even after percutaneous drainage. Appropriate treatment includes open surgical drainage along with antibiotic therapy.</p
Perceptions of Current Issues in Female Sport Nutrition From Elite Athletes, Practitioners, and Researchers
In response to the ongoing sex data gap, the present study provides a qualitative exploration of femalesā nutritional experiences in elite sporting environments. Semistructured interviews were conducted with multiple participant groups (n = 18), including athletes (n = 7), practitioners (n = 6), and researchers (n = 5) across differing disciplines within professional sporting organiza-tions and/or national governing bodies. Combined content and thematic analysis provided an insight into the specific factors influencing current sport nutrition practices. A common theme highlighted among all participant groups was the paradoxical struggle between adequate fueling for training and competition demands, and the fear this may impact body mass and body composition goals. This tension was identified as being rooted within athletesā perceptions of body image and driven by other participant groups and wider societal ideals. Each participant group also highlighted influences on cravings and approaches to food and dietary supplementation, centered around individual perceptions and challenges driven by symptomology associated with the female menstrual cycle and contraceptive use. To address these challenges, all participant groups called for more research to inform future change and continuing education pathways. In summary, this study contributes to providing a more complete understanding of elite female athlete sport nutrition experiences than currently exists. Multiple perspectives highlight the complexity of providing sport nutrition support to elite female athlete populations and directs future research, and practice, to reconsider one-size-fits-all approaches and acknowledge unique individual contexts which may influence these areas
An examination of content knowledge in formal coach education curriculum
Sport coaching can be seen as an interdisciplinary endeavour, where coaches integrate multiple disciplinary knowledges to support participants achieving a variety of desirable outcomes (e.g. learn new skills, meet new people, develop greater confidence). Limited research however has considered what knowledge has been used as the basis for curricula, or how it has been structured into formal coach education courses. This is remiss because coaches not only need to learn, but need to learn something to ultimately aid their own (and others) development. Therefore, the aim of this study was to examine what content knowledge contributed to the English FA intermediate (i.e. level 2) formal coach education course, and how this knowledge was structured to form a curriculum. Data were collected using a document analysis of National Governing Body (NGB) and awarding body documents (nā=ā10), as well as observing two formal coach education courses, and interviewing coach developers (nā=ā5) that delivered those courses. A deductive thematic analysis identified three themes: (1) A Curriculum Partially Informed by Research, (2) A Strongly Classified Curriculum and (3) A Curriculum also Includes āProfessional Knowledgeā. Findings reveal the socially constructed nature of content knowledge legitimised as worth knowing in formal coach education curricula. It prompts critical consideration of what knowledge is used (or not) and how this knowledge supports learners in the dynamic and often ambiguous context of coaching. The significance of the findings move beyond the case at hand, as wider educational institutions may wish to consider what content knowledge is used, and how it is structured within their own coach education and development provisions
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