1,644 research outputs found

    Is there evidence to support Porter-type policies?

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    The paper examines the views, often associated with Porter, that clusters with deep collaborative networks and established local supply chains have good performance. The view that good cluster performance is not connected to the industrial sector is also assessed. Data from a Department of Trade and Industry (DTI) study on UK clusters are used to assess the impact on performance (employment growth and international competitiveness) of cluster depth, the stage of development of local supply chains, and industrial sector. The results of the analysis of the DTI data on clusters do not provide strong support for Porter-type views on cluster policy. Although established clusters are linked to employment growth, deep clusters are not associated with employment growth or international competitiveness, and clusters in the services, and media, computer-related and biotechnology sectors are more likely than manufacturing clusters to have good performance. Some of the major policy implications of the results are discussed in the light of the literature on the importance of regional, national, and international networks for the performance of clusters

    B553: Consumer Packages for Maine Mcintosh Apples

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    Three kinds of consumer packages for apples were developed for testing in the 1955-56 marketing season. In developing these packages, the authors modified the jumble-pack, polyethylene package in a way that would protect the fruit from most of the bruising and still maintain almost complete visibility of the fruit. One consumer package developed was a long narrow polyethylene bag, another was a polyethylene bag with a divider insert, and the third package had a cell partition placed in a similar plastic bag. All three packages were well accepted by consumers in the Portland market.https://digitalcommons.library.umaine.edu/aes_bulletin/1085/thumbnail.jp

    A study of rotating globular clusters - the case of the old, metal-poor globular cluster NGC 4372

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    Aims: We present the first in-depth study of the kinematic properties and derive the structural parameters of NGC 4372 based on the fit of a Plummer profile and a rotating, physical model. We explore the link between internal rotation to different cluster properties and together with similar studies of more GCs, we put these in the context of globular cluster formation and evolution. Methods: We present radial velocities for 131 cluster member stars measured from high-resolution FLAMES/GIRAFFE observations. Their membership to the GC is additionally confirmed from precise metallicity estimates. Using this kinematic data set we build a velocity dispersion profile and a systemic rotation curve. Additionally, we obtain an elliptical number density profile of NGC 4372 based on optical images using a MCMC fitting algorithm. From this we derive the cluster's half-light radius and ellipticity as r_h=3.4'+/-0.04' and e=0.08+/-0.01. Finally, we give a physical interpretation of the observed morphological and kinematic properties of this GC by fitting an axisymmetric, differentially rotating, dynamical model. Results: Our results show that NGC 4372 has an unusually high ratio of rotation amplitude to velocity dispersion (1.2 vs. 4.5 km/s) for its metallicity. This, however, puts it in line with two other exceptional, very metal-poor GCs - M 15 and NGC 4590. We also find a mild flattening of NGC 4372 in the direction of its rotation. Given its old age, this suggests that the flattening is indeed caused by the systemic rotation rather than tidal interactions with the Galaxy. Additionally, we estimate the dynamical mass of the GC M_dyn=2.0+/-0.5 x 10^5 M_Sun based on the dynamical model, which constrains the mass-to-light ratio of NGC 4372 between 1.4 and 2.3 M_Sun/L_Sun, representative of an old, purely stellar population.Comment: Accepted for publication in A&A, 12 pages, 14 figures, 2 table

    A case-cohort study of human herpesvirus 8 seropositivity and incident prostate cancer in Tobago

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    <p>Abstract</p> <p>Background</p> <p>We previously reported a cross-sectional association between the presence of human herpesvirus 8 (HHV-8) serum antibodies and screen-detected prostate cancer in men living in Tobago. In the same study population, we examined the association between HHV-8 seropositivity and incident prostate cancer discovered at later screenings.</p> <p>Methods</p> <p>In 40-81 year-old men without prostate cancer discovered at initial digital rectal examination (DRE) and prostate-specific antigen (PSA) screening, a case-cohort design measured the association between baseline HHV-8 seropositivity (modified immunofluorescence assay for antibodies against HHV-8 lytic antigens) and incident prostate cancer detected at DRE and PSA screenings three or five years later.</p> <p>Results</p> <p>Analyses included 486 unique individuals, 96 incident prostate cancer cases, and 415 randomly selected subjects representing an at-risk cohort. By design, the random sub-cohort contained 25 incident prostate cancer cases. In the sub-cohort, the frequency of HHV-8 seropositivity increased across age groupings (40-49 years: 3.5%, 50-59 years: 13.6%, and ā‰„ 60 years: 22.9%). HHV-8 seropositivity was higher in men with elevated (ā‰„ 4.0 ng/mL) than men with non-elevated PSA at initial screening (30.4% <it>vs</it>. 9.9% seropositive; crude odds ratio (OR) 3.96, 95% confidence interval (CI) 1.53-10.2; age-adjusted OR 2.42, 95% CI 0.91-6.47). HHV-8 seropositivity did not increase incident prostate cancer risk (age-adjusted hazard ratio (HR) 0.88, 95% CI 0.46-1.69).</p> <p>Conclusions</p> <p>Case-cohort analysis did not identify association between HHV-8 seropositivity and incident prostate cancer. However, analyses uncovered possible association between HHV-8 and PSA (a marker of prostate inflammation). Co-occurrence of HHV-8 seropositivity and PSA elevation may explain cross-sectional association between HHV-8 and PSA screen-detected prostate cancer.</p

    Selection of tuning parameters in bridge regression models via Bayesian information criterion

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    We consider the bridge linear regression modeling, which can produce a sparse or non-sparse model. A crucial point in the model building process is the selection of adjusted parameters including a regularization parameter and a tuning parameter in bridge regression models. The choice of the adjusted parameters can be viewed as a model selection and evaluation problem. We propose a model selection criterion for evaluating bridge regression models in terms of Bayesian approach. This selection criterion enables us to select the adjusted parameters objectively. We investigate the effectiveness of our proposed modeling strategy through some numerical examples.Comment: 20 pages, 5 figure

    Contrast nephropathy in patients with impaired renal function: High versus low osmolar media

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    Contrast nephropathy in patients with impaired renal function: High versus low osmolar media. Prescription of low osmolar contrast to prevent nephrotoxicity in subjects with pre-existing renal impairment is costly and has not been clearly shown to be effective. We entered 249 subjects with a pre-contrast serum creatinine greater than 120 /xmol/liter (1.35 mg/dl) having cardiac catheterization or intravenous contrast into a randomized controlled trial comparing high and low osmolar contrast. The outcome assessed was a rise in serum creatinine repeated 48 to 72 hours after contrast. A further 117 patients entered the non-randomized prospective arm of the study. In the randomized study the serum creatinine rose by at least 25% after contrast in 8 of 117 (6.8%) given high and in 5 of 132 (3.8%) given low osmolar contrast (P > 0.05, one-tailed 95% confidence interval for the difference 3 to 7.8%). More severe renal failure (greater than 50% increase in serum creatinine) after contrast was uncommon (3.4% with high and 1.5% with low osmolar contrast). A rise in serum creatinine after contrast was significantly associated with the severity of the pre-contrast renal impairment and the presence of diabetes mellitus, but not with type of contrast. Diabetics with a serum creatinine greater than 200 Āµl/liter (2.25 mg/dl) pre-contrast had a highest risk of deterioration in renal function after contrast. We conclude that in patients with pre-existing renal impairment the incidence of contrast nephropathy was not significantly different comparing high osmolar and nonionic contrast. The potential benefit of nonionic contrast in moderate renal impairment is likely to be small, but trials in diabetics with severe renal impairment should be undertaken urgently

    Role of interferonā€Ī³ and inflammatory monocytes in driving colonic inflammation during acute Clostridium difficile infection in mice

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136491/1/imm12700.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136491/2/imm12700_am.pd

    The pancreatic Ī² cell is a key site for mediating the effects of leptin on glucose homeostasis

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    SummaryThe hormone leptin plays a crucial role in maintenance of body weight and glucose homeostasis. This occurs through central and peripheral pathways, including regulation of insulin secretion by pancreatic Ī² cells. To study this further in mice, we disrupted the signaling domain of the leptin receptor gene in Ī² cells and hypothalamus. These mice develop obesity, fasting hyperinsulinemia, impaired glucose-stimulated insulin release, and glucose intolerance, similar to leptin receptor null mice. However, whereas complete loss of leptin function causes increased food intake, this tissue-specific attenuation ofĀ leptin signaling does not alter food intake or satiety responses to leptin. Moreover, unlike other obese models, these mice have reduced fasting blood glucose. These results indicate that leptin regulation of glucose homeostasis extends beyond insulin sensitivity to influence Ī² cell function, independent of pathways controlling food intake. These data suggest that defects in this adipoinsular axis could contribute to diabetes associated with obesity

    129-derived Strains of Mice Are Deficient in DNA Polymerase Ī¹ and Have Normal Immunoglobulin Hypermutation

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    Recent studies suggest that DNA polymerase Ī· (polĪ·) and DNA polymerase Ī¹ (polĪ¹) are involved in somatic hypermutation of immunoglobulin variable genes. To test the role of polĪ¹ in generating mutations in an animal model, we first characterized the biochemical properties of murine polĪ¹. Like its human counterpart, murine polĪ¹ is extremely error-prone when catalyzing synthesis on a variety of DNA templates in vitro. Interestingly, when filling in a 1 base-pair gap, DNA synthesis and subsequent strand displacement was greatest in the presence of both pols Ī¹ and Ī·. Genomic sequence analysis of Poli led to the serendipitous discovery that 129-derived strains of mice have a nonsense codon mutation in exon 2 that abrogates production of polĪ¹. Analysis of hypermutation in variable genes from 129/SvJ (Poliāˆ’/āˆ’) and C57BL/6J (Poli+/+) mice revealed that the overall frequency and spectrum of mutation were normal in polĪ¹-deficient mice. Thus, either polĪ¹ does not participate in hypermutation, or its role is nonessential and can be readily assumed by another low-fidelity polymerase
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