411 research outputs found

    Shoreline situation report, Middlesex County, Virginia

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    It is the objective of this report to supply an assessment, and at least a partial integration, of those important shoreland parameters and characteristics which will aid the planners and the managers of the shorelands in making the best decisions for the utilization of this limited and very valuable resource. The report gives particular attention to the problem of shore erosion and to recommendations concerning the alleviation of the impact of this problem. In addition we \u27have tried to include in our assessment some of the potential uses of the shoreline, particularly with respect to recreational use, since such information could be of considerable value in the way a particular segment of coast is perceived by potential users

    Aircraft computations using multigrid and an unstructured parallel library

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    This paper examines the application of unstructured multigrid, using a sequence of independent tetrahedral grids. The test cases examined are for inviscid flow over an aircraft and an M6 wing. The sensitivity of the method to grid sequence and cycling strategy are investigated. \ud \ud All of the calculations were performed on a parallel computer. This was achieved by using the OPlus library which, by the straightforward insertion of subroutine calls, facilitates parallelisation of the resulting code. A single source OPlus application code can be compiled to executed on either a parallel or sequential machine. This greatly increases the usability of the parallel machine, and the maintainability of the code

    Homogeneity and persistence of transgene expression by omitting antibiotic selection in cell line isolation

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    Nonuniform, mosaic expression patterns of transgenes are often linked to transcriptional silencing, triggered by epigenetic modifications of the exogenous DNA. Such phenotypes are common phenomena in genetically engineered cells and organisms. They are widely attributed to features of transgenic transcription units distinct from endogenous genes, rendering them particularly susceptible to epigenetic downregulation. Contrary to this assumption we show that the method used for the isolation of stably transfected cells has the most profound impact on transgene expression patterns. Standard antibiotic selection was directly compared to cell sorting for the establishment of stable cells. Only the latter procedure could warrant a high degree of uniformity and stability in gene expression. Marker genes useful for the essential cell sorting step encode mostly fluorescent proteins. However, by combining this approach with site-specific recombination, it can be applied to isolate stable cell lines with the desired expression characteristics for any gene of interest

    Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa)

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    The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches

    Cellular Basis for Response Diversity in the Olfactory Periphery

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    An emerging idea in olfaction is that temporal coding of odor specificity can be intrinsic to the primary olfactory receptor neurons (ORNs). As a first step towards understanding whether lobster ORNs are capable of generating odor-specific temporal activity and what mechanisms underlie any such heterogeneity in discharge pattern, we characterized different patterns of activity in lobster ORNs individually and ensemble using patch-clamp recording and calcium imaging. We demonstrate that lobster ORNs show tonic excitation, tonic inhibition, phaso-tonic excitation, and bursting, and that these patterns are faithfully reflected in the calcium signal. We then demonstrate that the various dynamic patterns of response are inherent in the cells, and that this inherent heterogeneity is largely determined by heterogeneity in the underlying intrinsic conductances

    The cost-effectiveness of a new disease management model for frail elderly living in homes for the elderly, design of a cluster randomized controlled clinical trial

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    <p>Abstract</p> <p>Background</p> <p>The objective of this article is to describe the design of a study to evaluate the clinical and economic effects of a Disease Management model on functional health, quality of care and quality of life of persons living in homes for the elderly.</p> <p>Methods</p> <p>This study concerns a cluster randomized controlled clinical trial among five intervention homes and five usual care homes in the North-West of the Netherlands with a total of over 500 residents. All persons who are not terminally ill, are able to be interviewed and sign informed consent are included. For cognitively impaired persons family proxies will be approached to provide outcome information. The Disease Management Model consists of several elements: (1) Trained staff carries out a multidimensional assessment of the patients functional health and care needs with the interRAI Long Term Care Facilities instrument (LTCF). Computerization of the LTCF produces immediate identification of problem areas and thereby guides individualized care planning. (2) The assessment outcomes are discussed in a Multidisciplinary Meeting (MM) with the nurse, primary care physician, nursing home physician and Psychotherapist and if necessary other members of the care team. The MM presents individualized care plans to manage or treat modifiable disabilities and risk factors. (3) Consultation by an nursing home physician and psychotherapist is offered to the frailest residents at risk for nursing home admission (according to the interRAI LTCF). Outcome measures are Quality of Care indicators (LTCF based), Quality Adjusted Life Years (Euroqol), Functional health (SF12, COOP-WONCA), Disability (GARS), Patients care satisfaction (QUOTE), hospital and nursing home days and mortality, health care utilization and costs.</p> <p>Discussion</p> <p>This design is unique because no earlier studies were performed to evaluate the effects and costs of this Disease Management Model for disabled persons in homes for the elderly on functional health and quality of care.</p> <p>Trail registration number</p> <p>ISRCTN11076857</p

    Physician-assisted suicide: a review of the literature concerning practical and clinical implications for UK doctors

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    BACKGROUND: A bill to legalize physician-assisted suicide in the UK recently made significant progress in the British House of Lords and will be reintroduced in the future. Until now there has been little discussion of the clinical implications of physician-assisted suicide for the UK. This paper describes problematical issues that became apparent from a review of the medical and psychiatric literature as to the potential effects of legalized physician-assisted suicide. DISCUSSION: Most deaths by physician-assisted suicide are likely to occur for the illness of cancer and in the elderly. GPs will deal with most requests for assisted suicide. The UK is likely to have proportionately more PAS deaths than Oregon due to the bill's wider application to individuals with more severe physical disabilities. Evidence from other countries has shown that coercion and unconscious motivations on the part of patients and doctors in the form of transference and countertransference contribute to the misapplication of physician-assisted suicide. Depression influences requests for hastened death in terminally ill patients, but is often under-recognized or dismissed by doctors, some of whom proceed with assisted death anyway. Psychiatric evaluations, though helpful, do not solve these problems. Safeguards that are incorporated into physician-assisted suicide criteria probably decrease but do not prevent its misapplication. SUMMARY: The UK is likely to face significant clinical problems arising from physician-assisted suicide if it is legalized. Terminally ill patients with mental illness, especially depression, are particularly vulnerable to the misapplication of physician-assisted suicide despite guidelines and safeguards

    The Arabidopsis thaliana Homeobox Gene ATHB12 Is Involved in Symptom Development Caused by Geminivirus Infection

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    BACKGROUND: Geminiviruses are single-stranded DNA viruses that infect a number of monocotyledonous and dicotyledonous plants. Arabidopsis is susceptible to infection with the Curtovirus, Beet severe curly top virus (BSCTV). Infection of Arabidopsis with BSCTV causes severe symptoms characterized by stunting, leaf curling, and the development of abnormal inflorescence and root structures. BSCTV-induced symptom development requires the virus-encoded C4 protein which is thought to interact with specific plant-host proteins and disrupt signaling pathways important for controlling cell division and development. Very little is known about the specific plant regulatory factors that participate in BSCTV-induced symptom development. This study was conducted to identify specific transcription factors that are induced by BSCTV infection. METHODOLOGY/PRINCIPAL FINDINGS: Arabidopsis plants were inoculated with BSCTV and the induction of specific transcription factors was monitored using quantitative real-time polymerase chain reaction assays. We found that the ATHB12 and ATHB7 genes, members of the homeodomain-leucine zipper family of transcription factors previously shown to be induced by abscisic acid and water stress, are induced in symptomatic tissues of Arabidopsis inoculated with BSCTV. ATHB12 expression is correlated with an array of morphological abnormalities including leaf curling, stunting, and callus-like structures in infected Arabidopsis. Inoculation of plants with a BSCTV mutant with a defective c4 gene failed to induce ATHB12. Transgenic plants expressing the BSCTV C4 gene exhibited increased ATHB12 expression whereas BSCTV-infected ATHB12 knock-down plants developed milder symptoms and had lower ATHB12 expression compared to the wild-type plants. Reporter gene studies demonstrated that the ATHB12 promoter was responsive to BSCTV infection and the highest expression levels were observed in symptomatic tissues where cell cycle genes also were induced. CONCLUSIONS/SIGNIFICANCE: These results suggest that ATHB7 and ATHB12 may play an important role in the activation of the abnormal cell division associated with symptom development during geminivirus infection
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