817 research outputs found

    Flow and Jamming of Granular Suspensions in Foams

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    The drainage of particulate foams is studied under conditions where the particles are not trapped individually by constrictions of the interstitial pore space. The drainage velocity decreases continuously as the particle volume fraction ϕp\phi_{p} increases. The suspensions jam - and therefore drainage stops - for values ϕp\phi_{p}^{*} which reveal a strong effect of the particle size. In accounting for the particular geometry of the foam, we show that ϕp\phi_{p}^{*} accounts for unusual confinement effects when the particles pack into the foam network. We model quantitatively the overall behavior of the suspension - from flow to jamming - by taking into account explicitly the divergence of its effective viscosity at ϕp\phi_{p}^{*}. Beyond the scope of drainage, the reported jamming transition is expected to have a deep significance for all aspects related to particulate foams, from aging to mechanical properties

    Insulin clearance and the incidence of type 2 diabetes in Hispanics and African Americans: the IRAS Family Study.

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    ObjectiveWe aimed to identify factors that are independently associated with the metabolic clearance rate of insulin (MCRI) and to examine the association of MCRI with incident type 2 diabetes in nondiabetic Hispanics and African Americans.Research design and methodsWe investigated 1,116 participants in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study with baseline examinations from 2000 to 2002 and follow-up examinations from 2005 to 2006. Insulin sensitivity (S(I)), acute insulin response (AIR), and MCRI were determined at baseline from frequently sampled intravenous glucose tolerance tests. MCRI was calculated as the ratio of the insulin dose over the incremental area under the curve of insulin. Incident diabetes was defined as fasting glucose ≥126 mg/dL or antidiabetic medication use by self-report.ResultsWe observed that S(I) and HDL cholesterol were independent positive correlates of MCRI, whereas fasting insulin, fasting glucose, subcutaneous adipose tissue, visceral adipose tissue, and AIR were independent negative correlates (all P < 0.05) at baseline. After 5 years of follow-up, 71 (6.4%) participants developed type 2 diabetes. Lower MCRI was associated with a higher risk of incident diabetes after adjusting for demographics, lifestyle factors, HDL cholesterol, indexes of obesity and adiposity, and insulin secretion (odds ratio 2.01 [95% CI 1.30-3.10], P = 0.0064, per one-SD decrease in loge-transformed MCRI).ConclusionsOur data showed that lower MCRI predicts the incidence of type 2 diabetes

    Análise do setor de transporte marítimo no Panamá - 1970-2009

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    On this article was made an analysis of the importance of the maritime transportation sector in Panamá. The statistics prove that this is the main traffic network of merchandise, with less cost, security and efficiency. For these reasons, the sector of maritime transportation is passing through technologic changes on the infrastructure of ships, ports and logistics strategies to attend the request of the cargo capacity to be transported. This way, the general objective of this paper is to analyze the development of this sector in Panama and its increase, inside the general perspective of the worldwide maritime industry. A survey was made about the history of this industry, characterizing the maritime transportation sector, determining the main technical and operational changes that occurred since 1970. The research also indicate that, how Panama is getting prepared to envisage the request for this activity. Key words: Marine transportation; Panamá; Trading. Artigo recebido em 03 fev. 2011.Neste artigo, é feita uma análise da importância do setor de transporte marítimo no Panamá. Os dados comprovam que essa é a principal rede de circulação de mercadorias, com menor custo, segurança e eficiência. Para atender à demanda de volume de carga transportada, o setor de transporte marítimo vem sofrendo alterações tecnológicas na infraestrutura dos navios, dos portos e nas estratégicas logísticas. Assim, o objetivo geral deste trabalho é analisar o desenvolvimento desse setor no Panamá e sua evolução dentro do quadro geral da indústria marítima mundial. Para isso, fez-se o levantamento histórico dessa indústria, caracterizando-se o setor de transportes marítimos e determinando-se as principais mudanças técnicas e operacionais ocorridas a partir de 1970. A pesquisa mostra, ainda, a preparação do Panamá para enfrentar a demanda por essa atividade

    A Galactic O-Star Catalog

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    We have produced a catalog of 378 Galactic O stars with accurate spectral classifications which is complete for V<8 but includes many fainter stars. The catalog provides cross-identifications with other sources; coordinates (obtained in most cases from Tycho-2 data); astrometric distances for 24 of the nearest stars; optical (Tycho-2, Johnson, and Stromgren) and NIR photometry; group membership, runaway character, and multiplicity information; and a web-based version with links to online services.Comment: 76 pages, 13 tables, and 3 figures. Accepted for publication in Astrophysical Journal. Online version of the catalog available at http://www.stsci.edu/~jmaiz/GOSmain.htm

    Components of Metabolic Syndrome and 5-Year Chance in Insulin Clearance - The Resistance Atherosclerosis Study (IRAS)

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    Aims Cross-sectional evidence indicates that abdominal adiposity, hypertension, dyslipidaemia and glycaemia are associated with reduced metabolic clearance rate of insulin (MCRI). Little is known about the progression of MCRI and whether components of metabolic syndrome are associated with the change in MCRI. In this study, we examined the association between components of metabolic syndrome and the 5-year change of MCRI. Methods At baseline and 5-year follow-up, we measured fasting plasma triglycerides (TG), high-density lipoprotein (HDL) cholesterol, blood pressure (BP), waist circumference (WC) and fasting blood glucose (FBG) in 784 non-diabetic participants in the Insulin Resistance Atherosclerosis Study. MCRI, insulin sensitivity (SI) and acute insulin response (AIR) were determined from frequently sampled intravenous glucose tolerance tests. Results We observed a 29% decline of MCRI at follow-up. TG, systolic BP and WC at baseline were inversely associated with a decline of MCRI regression models adjusted for age, sex, ethnicity, smoking, alcohol consumption, energy expenditure, family history of diabetes, BMI, SI and AIR [β = −0.057 (95% confidence interval, CI: −0.11, −0.0084) for TG, β = −0.0019 (95% CI: −0.0035, −0.00023) for systolic BP and β  = −0.0084 (95% CI: −0.013, −0.0039) for WC; all p \u3c 0.05]. Higher HDL cholesterol at baseline was associated with an increase in MCRI [multivariable-adjusted β = 0.0029 (95% CI: 0.0010, 0.0048), p = 0.002]. FBG at baseline was not associated with MCRI at follow-up [multivariable-adjusted β = 0.0014 (95% CI: −0.0026, 0.0029)]. Conclusions MCRI declined progressively over 5 years in a non-diabetic cohort. Components of metabolic syndrome at baseline were associated with a significant change in MCRI

    Management of congenital nephrotic syndrome: consensus recommendations of the ERKNet-ESPN Working Group

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    Congenital nephrotic syndrome (CNS) is a heterogeneous group of disorders characterized by nephrotic-range proteinuria, hypoalbuminaemia and oedema, which manifest in utero or during the first 3 months of life. The main cause of CNS is genetic defects in podocytes; however, it can also be caused, in rare cases, by congenital infections or maternal allo-immune disease. Management of CNS is very challenging because patients are prone to severe complications, such as haemodynamic compromise, infections, thromboses, impaired growth and kidney failure. In this consensus statement, experts from the European Reference Network for Kidney Diseases (ERKNet) and the European Society for Paediatric Nephrology (ESPN) summarize the current evidence and present recommendations for the management of CNS, including the use of renin–angiotensin system inhibitors, diuretics, anticoagulation and infection prophylaxis. Therapeutic management should be adapted to the clinical severity of the condition with the aim of maintaining intravascular euvolaemia and adequate nutrition, while preventing complications and preserving central and peripheral vessels. We do not recommend performing routine early nephrectomies but suggest that they are considered in patients with severe complications despite optimal conservative treatment, and before transplantation in patients with persisting nephrotic syndrome and/or a WT1-dominant pathogenic variant

    Entanglement of spin waves among four quantum memories

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    Quantum networks are composed of quantum nodes that interact coherently by way of quantum channels and open a broad frontier of scientific opportunities. For example, a quantum network can serve as a `web' for connecting quantum processors for computation and communication, as well as a `simulator' for enabling investigations of quantum critical phenomena arising from interactions among the nodes mediated by the channels. The physical realization of quantum networks generically requires dynamical systems capable of generating and storing entangled states among multiple quantum memories, and of efficiently transferring stored entanglement into quantum channels for distribution across the network. While such capabilities have been demonstrated for diverse bipartite systems (i.e., N=2 quantum systems), entangled states with N > 2 have heretofore not been achieved for quantum interconnects that coherently `clock' multipartite entanglement stored in quantum memories to quantum channels. Here, we demonstrate high-fidelity measurement-induced entanglement stored in four atomic memories; user-controlled, coherent transfer of atomic entanglement to four photonic quantum channels; and the characterization of the full quadripartite entanglement by way of quantum uncertainty relations. Our work thereby provides an important tool for the distribution of multipartite entanglement across quantum networks.Comment: 4 figure
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