3,198 research outputs found

    The Impact of the Kansas Wheat Breeding Program on Wheat Yields, 1911–2006

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    This paper quantifies advances of the Kansas Agricultural Experiment Station (KAES) wheat breeding program for two time periods: (1) 1911 to 2006 and (2) 1977 to 2006. Using multiple regression, increases in yields of wheat varieties grown in Kansas are quantified, holding growing conditions and other improvements in productivity constant. Differences in KAES variety yields and those released by other public and private breeders are quantified. During the ‘‘new age’’ of wheat breeding (1977–2006), wheat breeding alone is found to have increased yields by 6.182 bushels per acre, or an average increase of 0.206 bushels per year.wheat yield, public wheat breeding, multiplicative heteroscedasticity, economic impact of technological change, Agribusiness, Farm Management, O13, Q16,

    Concentric cracking of grape berries

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    Light microscopy has been used to study the anatomy of "cracks" and "splits" in grape berries. In cracking, fine concentric surface cracks in the skin are formed around the base of the pedicel or at the stylar end. Cracks usually involved rupture of the cuticle and epidermal layer of cells only. In splitting, the cuticle, epidermis, sub-epiclermis and outer pericarp cells were ruptured. Suberization was evident in the cells beneath cracks, but was not present in the cells around splits. Possible mechanisms of epidermal damage and penetration of microorganisms are discussed in relation to cracking ancl splitting.Konzentrisches Aufreißen von WeinbeerenBei Traubenbeeren wurden Schrunden (,,cracks") und Platzwunden (,,splits") beobachtet, deren anatomische Verhältnisse lichtmikroskopisch untersucht wurden. Die Schrunden bilden sich als feine, konzentrische Oberflächenrisse um den Beerenansatz oder am apikalen Ende der Beere. In diesem Falle sind gewöhnlich nur die Kutikula und die epidermale Zellschicht aufgerissen. Die Platzwunden erstrecken sich dagegen auf Kutikula, Epidermis, Subepidermis und die äußeren Perikarpzellen. In den Zellen unterhalb der Schrunden ließ sich Verkorkung nachweisen, nicht jedoch in den an die Platzwunden angrenzenden Zellen. Mechanismen, die für die Beschädigung der Epidermis verantwortlich sein könnten, sowie das Eindringen von Mikroorganismen werden im Zusammenhang mit dem Auftreten von Schrunden und Platzwunden diskutiert

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    Addressing Profound Disadvantages to Improve Indigenous Health and Reduce Hospitalisation: A Collaborative Community Program in Remote Northern Territory

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    BACKGROUND: Aboriginal people in rural and remote areas of the Northern Territory of Australia have suffered longstanding issues of homelessness and profound health and social inequities. The town and region of Katherine are particularly impacted by such inequities and have the highest rates of homelessness in Australia, composed almost entirely of Aboriginal people who represent 51% of the total population of 24,000 people. The region is serviced by a 60-bed hospital, and a small cohort of frequent attenders (FAs) represent 11% of the Emergency Department (ED) case load. The vast majority of FAs are Aboriginal and have very high burdens of social inequity and homelessness. FAs are a challenge to efficient and effective use of resources for most hospitals around the world, and investment in programs to address underlying social and chronic health issues contributing to frequent attendance have been demonstrated to be effective. METHODS: These are the interim findings of a prospective cohort study using five sources of linked health and related data to evaluate a community-based case management pilot in a culturally competent framework to support frequent attenders to the Katherine Hospital ED. FAs were defined as people with six or more presentations in 12 preceding months. The intervention composed of a community-based case management program with a multi-agency service delivery addressing underlying vulnerabilities contributing to ED presentations. RESULTS: Among this predominantly Aboriginal cohort (91%), there were high rates of homelessness (64%), food insecurity (60%) and alcohol misuse (64%), limited access to transport, and complex comorbidities (average of 2.8 chronic conditions per client). Following intervention, there was a statistically significant reduction in ED presentations (IRR 0.77, 95% CI 0.69-0.85), increased engagement with primary health care (IRR 1.90, 95% CI 1.78-2.03), and ambulance utilisation (IRR 1.21, 95% CI 1.07-1.38). Reductions in hospital admissions (IRR 0.93, 95% CI 0.77-1.10) and aeromedical retrievals (IRR 0.67, 95% CI 0.35-1.20) were not statistically significant. CONCLUSIONS: This study demonstrates the short-term impacts of community-led case management extending beyond the hospital setting, to address causes of recurrent ED presentations among people with complex social and medical backgrounds. Improving engagement with primary care is a particularly important outcome given the national impetus to reduce preventable hospital admissions

    Using historical woodland creation to construct a long-term, large-scale natural experiment: The WrEN project

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    Natural experiments have been proposed as a way of complementing manipulative experiments to improve ecological understanding and guide management. There is a pressing need for evidence from such studies to inform a shift to landscape-scale conservation, including the design of ecological networks. Although this shift has been widely embraced by conservation communities worldwide, the empirical evidence is limited and equivocal, and may be limiting effective conservation. We present principles for well-designed natural experiments to inform landscape-scale conservation and outline how they are being applied in the WrEN project, which is studying the effects of 160years of woodland creation on biodiversity in UK landscapes. We describe the study areas and outline the systematic process used to select suitable historical woodland creation sites based on key site- and landscape-scale variables – including size, age, and proximity to other woodland. We present the results of an analysis to explore variation in these variables across sites to test their suitability as a basis for a natural experiment. Our results confirm that this landscape satisfies the principles we have identified and provides an ideal study system for a long-term, large-scale natural experiment to explore how woodland biodiversity is affected by different site and landscape attributes. The WrEN sites are now being surveyed for a wide selection of species that are likely to respond differently to site- and landscape-scale attributes and at different spatial and temporal scales. The results from WrEN will help develop detailed recommendations to guide landscape-scale conservation, including the design of ecological networks. We also believe that the approach presented demonstrates the wider utility of well-designed natural experiments to improve our understanding of ecological systems and inform policy and practice

    Learning To Be Affected: Social suffering and total pain at life’s borders.

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    The practice of Live Sociology in situations of pain and suffering is the author’s focus. An outline of the challenges of understanding pain is followed by a discussion of Bourdieu’s ‘social suffering’ (1999) and the palliative care philosophy of ‘total pain’. Using examples from qualitative research on disadvantaged dying migrants in the UK, attention is given to the methods that are improvised by dying people and care practitioners in attempts to bridge intersubjective divides, where the causes and routes of pain can be ontologically and temporally indeterminate and/or withdrawn. The paper contends that these latter phenomena are the incitement for the inventive bridging and performative work of care and Live Sociological methods, both of which are concerned with opposing suffering. Drawing from the ontology of total pain, I highlight the importance of (i) an engagement with a range of materials out of which attempts at intersubjective bridging can be produced, and which exceed the social, the material, and the temporally linear; and (ii) an empirical sensibility that is hospitable to the inaccessible and non-relational

    Securing recruitment and obtaining informed consent in minority ethnic groups in the UK

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    Background: Previous health research has often explicitly excluded individuals from minority ethnic backgrounds due to perceived cultural and communication difficulties, including studies where there might be language/literacy problems in obtaining informed consent. This study addressed these difficulties by developing audio-recorded methods of obtaining informed consent and recording data. This report outlines 1) our experiences with securing recruitment to a qualitative study investigating alternative methods of data collection, and 2) the development of a standardised process for obtaining informed consent from individuals from minority ethnic backgrounds whose main language does not have an agreed written form. Methods: Two researchers from South Asian backgrounds recruited adults with Type 2 diabetes whose main language was spoken and not written, to attend a series of focus groups. A screening tool was used at recruitment in order to assess literacy skills in potential participants. Informed consent was obtained using audio-recordings of the patient information and recording patients' verbal consent. Participants' perceptions of this method of obtaining consent were recorded. Results: Recruitment rates were improved by using telephone compared to face-to-face methods. The screening tool was found to be acceptable by all potential participants. Audio-recorded methods of obtaining informed consent were easy to implement and accepted by all participants. Attrition rates differed according to ethnic group. Snowballing techniques only partly improved participation rates. Conclusion: Audio-recorded methods of obtaining informed consent are an acceptable alternative to written consent in study populations where literacy skills are variable. Further exploration of issues relating to attrition is required, and a range of methods may be necessary in order to maximise response and participation

    Statistical properties of power-law random banded unitary matrices in the delocalization-localization transition regime

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    Power-law random banded unitary matrices (PRBUM), whose matrix elements decay in a power-law fashion, were recently proposed to model the critical statistics of the Floquet eigenstates of periodically driven quantum systems. In this work, we numerically study in detail the statistical properties of PRBUM ensembles in the delocalization-localization transition regime. In particular, implications of the delocalization-localization transition for the fractal dimension of the eigenvectors, for the distribution function of the eigenvector components, and for the nearest neighbor spacing statistics of the eigenphases are examined. On the one hand, our results further indicate that a PRBUM ensemble can serve as a unitary analog of the power-law random Hermitian matrix model for Anderson transition. On the other hand, some statistical features unseen before are found from PRBUM. For example, the dependence of the fractal dimension of the eigenvectors of PRBUM upon one ensemble parameter displays features that are quite different from that for the power-law random Hermitian matrix model. Furthermore, in the time-reversal symmetric case the nearest neighbor spacing distribution of PRBUM eigenphases is found to obey a semi-Poisson distribution for a broad range, but display an anomalous level repulsion in the absence of time-reversal symmetry.Comment: 10 pages + 13 fig
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