310 research outputs found
The Effect of Side Traps on Ballistic Transistor in Kondo Regime
The effect of side-traps on conductance is calculated in the range of
slave-boson mean field theory, especially when there are electrodes on both
sides of the conductor.
This corresponds to an investigation of transport properties in future
ballistic transistors. An intrinsic dip as a result of the interference effect
(Fano-Kondo effect) is expected to be observed as one of interesting interplays
between physics and engineering devices.Comment: 3 pages, 5 figures. 2006 International Conference on Solid State
Devices and Materials (SSDM2006), Sept. 12-15, 2006, Yokohama, Japa
Image Construction as a Strategy of Resistance by Progressive Community Organizations
This article presents research findings on image construction as a strategy of resistance used by progressive community agencies to be responsive to the increasing marginalization of their service users in current times. The agencies project nuanced images in representing their work to service users, funders and stakeholders and community partner agencies. These nuanced images serve to demonstrate the multiple and complex identities of these agencies. The agencies have used this strategy successfully to reclaim their power with funders and use their power effectively in making their services responsive and relevant to the situations of service users. The article provides an interesting presentation on the dynamics of the use of this strategy by progressive community organizations.Cet article présente quelques résultats d’une recherche portant sur la construction de l’image comme stratégie de résistance chez des organismes communautaires progressistes. Ceux-ci y ont actuellement recours afin de réagir adéquatement à l’accroissement de la marginalisation de leurs usagers et usagères. Ces organismes recourent à de multiples images et représentations selon qu’ils s’adressent à des usagers et usagères, des bailleurs de fonds ou des organismes communautaires partenaires. Cette représentation différenciée de leurs interventions démontre le caractère multiple et complexe des identités de ces organismes. Plus encore, en employant des stratégies de construction d’images, ces organismes communautaires progressistes ont réussi à modifier les rapports de pouvoir entre les bailleurs de fonds et eux. Cette stratégie a aussi permis à ces organismes de fournir des réponses pertinentes et adaptées aux réalités de leurs usagers et usagères. Enfin, cet article offre une lecture intéressante des dynamiques sous-jacentes à cette stratégie et, plus particulièrement, à son recours par des organismes communautaires progressistes
Body size shapes inter-specific migratory behaviour: evidence from individual tracks of long-distance migratory shorebirds
Migration is a common phenomenon across many animal taxa. Understanding how migration scales with body size across species is fundamental in the development of migration theory and in making size‐related predictions. Although aerodynamic theory and ecophysiological scaling laws have assisted greatly in generating such predictions, their verifications have been limited by a lack of empirical data across a range of body sizes. The recent development of ultra‐light tracking devices and its rapid application to migration now allows us to put theory to the test. We used tracking data of seven closely related migratory sandpiper species (family Scolopacidae) along the East Asian‐Australasian Flyway to compare their migratory behaviour when migrating towards the breeding grounds as a function of size (50–750 g). We found a marked decline in migration speed (migration distance divided by total migration duration, including time at stopover sites and in flight) with size. Departure date from the non‐breeding (i.e. wintering) ground and arrival date at the breeding ground also scaled negatively with size. Total migration duration, migration distance, total staging duration (the number of days staying at stopover sites plus days preparing, i.e. fuelling, prior to initial migration) and step length (distance covered within one migratory leg) were not significantly related with size. Correction for phylogeny showed consistent results for all variables. Besides improving our fundamental understanding of inter‐specific variation in migration behaviours, the finding of a clear scaling with size in migration speed and migration timing highlight differential size related capabilities and constraints of migrants. Migratory birds, including sandpipers, are declining on a global scale and particularly along the East Asian‐Australasian Flyway. This notion of size‐dependency in migratory traits may have a bearing on their vulnerability to specific environmental disturbances along their flyways
Bada Bang, Bada Boom: Dispersal of fall migrating cormorants to protect sportfish on Oneida Lake, New York
The interior population of double-crested cormorants (Phalacrocorax auritus) continues to increase. As a result, conflicts between human interests and cormorants have intensified. The impacts of nesting, roosting, and migrating cormorants include predation at aquaculture facilities, interspecific competition with rare species including common terns {Sterna hirundo), and impacts to private property. In addition, heightened public and scientific debate regarding cormorant impacts on sportfish has accelerated the need for effective, socially acceptable methods for managing local conflicts. In 1998 and 1999, USDA, APHIS, Wildlife Services; the New York State Department of Environmental Conservation; and USGS, New York Fish and Wildlife Research Cooperative collaborated on a pilot project to investigate prospective methods and strategies for reducing predation of yellow perch (Perca flavescens) and walleye (Stizostedion vitreum) by fall migrating cormorants on Oneida Lake, New York. The goal of the cooperative program was to reduce stopover time, thereby reducing predation on fish stocks by migrating cormorants. A lakewide integrated non-lethal harassment and roost management program was initiated to disperse local and migrating cormorants from September to October each year. A variety of methods were used to manage cormorants including: electronic guards, propane cannons, mylar tape, human effigies, pyrotechnics, and dispersing birds with a boat. Harassment was focused on birds loafing on the water as well as day and night roosting sites (8 day and 2 night roosts). A total of 52,840 cormorants was dispersed (in many cases individual birds were harassed multiple times) using 1,518 pyrotechnics and 649 staff hours on the lake during the 2 years of the program. Surveys documented a 61%-98% reduction of the cormorants population on Oneida Lake compared to mean counts during the same time period from 1995-1997. Estimated total annual fish consumption by cormorants was reduced by 30% in 1998. Some off-site impacts of the program were seen with increased flocks of cormorants documented on nearby lakes
Activation of PPARγ by Rosiglitazone Does Not Negatively Impact Male Sex Steroid Hormones in Diabetic Rats
Peroxisome proliferator-activated receptor gamma (PPARγ) activation decreased serum testosterone (T) in women with hyperthecosis and/or polycystic ovary syndrome and reduced the conversion of androgens to estradiol (E2) in female rats. This implies modulation of female sex steroid hormones by PPARγ. It is not clear if PPARγ modulates sex steroid hormones in diabetic males. Because PPARγ activation by thiazolidinedione increased insulin sensitivity in type 2 diabetes, understanding the long term impact of PPARγ activation on steroid sex hormones in males is critical. Our objective was to determine the effect of PPARγ activation on serum and intratesticular T, luteinizing hormone (LH), follicle stimulating hormone (FSH) and E2 concentrations in male Zucker diabetic fatty (ZDF) rats treated with the PPARγ agonist rosiglitazone (a thiazolidinedione). Treatment for eight weeks increased PPARγ mRNA and protein in the testis and elevated serum adiponectin, an adipokine marker for PPARγ activation. PPARγ activation did not alter serum or intratesticular T concentrations. In contrast, serum T level but not intratesticular T was reduced by diabetes. Neither diabetes nor PPARγ activation altered serum E2 or gonadotropins FSH and LH concentrations. The results suggest that activation of PPARγ by rosiglitazone has no negative impact on sex hormones in male ZDF rats
Exploring access to end of life care for ethnic minorities with end stage kidney disease through recruitment in action research
BACKGROUND: Variation in provision of palliative care in kidney services and practitioner concerns to provide equitable access led to the development of this study which focussed on the perspectives of South Asian patients and their care providers. As people with a South Asian background experience a higher risk of Type 2 Diabetes (T2DM) and end stage kidney failure (ESKF) compared to the majority population but wait longer for a transplant, there is a need for end of life care to be accessible for this group of patients. Furthermore because non English speakers and people at end of life are often excluded from research there is a dearth of research evidence with which to inform service improvement. This paper aims to explore issues relating to the process of recruitment of patients for a research project which contribute to our understanding of access to end of life care for ethnic minority patients in the kidney setting. METHODS: The study employed an action research methodology with interviews and focus groups to capture and reflect on the process of engaging with South Asian patients about end of life care. Researchers and kidney care clinicians on four NHS sites in the UK recruited South Asian patients with ESKF who were requiring end of life care to take part in individual interviews; and other clinicians who provided care to South Asian kidney patients at end of life to take part in focus groups exploring end of life care issues. In action research planning, action and evaluation are interlinked and data were analysed with emergent themes fed back to care providers through the research cycle. Reflections on the process of patient recruitment generated focus group discussions about access which were analysed thematically and reported here. RESULTS: Sixteen patients were recruited to interview and 45 different care providers took part in 14 focus groups across the sites. The process of recruiting patients to interview and subsequent focus group data highlighted some of the key issues concerning access to end of life care. These were: the identification of patients approaching end of life; and their awareness of end of life care; language barriers and informal carers' roles in mediating communication; and contrasting cultures in end of life kidney care. CONCLUSIONS: Reflection on the process of recruitment in this action research study provided insight into the complex scenario of end of life in kidney care. Some of the emerging issues such as the difficulty identifying patients are likely to be common across all patient groups, whilst others concerning language barriers and third party communication are more specific to ethnic minorities. A focus on South Asian ethnicity contributes to better understanding of patient perspectives and generic concepts as well as access to end of life kidney care for this group of patients in the UK. Action research was a useful methodology for achieving this and for informing future research to include informal carers and other ethnic groups.Peer reviewedFinal Published versio
The Mass of the Lightest Supersymmetric Higgs Boson beyond the Leading Logarithm Approximation
We examine the radiative corrections to the mass of the lightest Higgs boson
in the minimal supersymmetric extension of the standard model. We use the
renormalization-group improved effective potential which includes the
next-to-leading-order contributions. We find that, contrary to the result of
Espinosa and Quir\'os, the higher-order corrections to the lightest Higgs boson
mass are non-negligible, adding GeV ( GeV) to the result in the
leading logarithm approximation for the range of top quark mass and for the supersymmetric breaking scale (). Also we find that our result is
stable under the change of the renormalization parameter .Comment: 17 pages (2 figures not included
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