2,589 research outputs found

    Thermoelastic Damping in Micro- and Nano-Mechanical Systems

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    The importance of thermoelastic damping as a fundamental dissipation mechanism for small-scale mechanical resonators is evaluated in light of recent efforts to design high-Q micrometer- and nanometer-scale electro-mechanical systems (MEMS and NEMS). The equations of linear thermoelasticity are used to give a simple derivation for thermoelastic damping of small flexural vibrations in thin beams. It is shown that Zener's well-known approximation by a Lorentzian with a single thermal relaxation time slightly deviates from the exact expression.Comment: 10 pages. Submitted to Phys. Rev.

    Generic Subsequence Matching Framework: Modularity, Flexibility, Efficiency

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    Subsequence matching has appeared to be an ideal approach for solving many problems related to the fields of data mining and similarity retrieval. It has been shown that almost any data class (audio, image, biometrics, signals) is or can be represented by some kind of time series or string of symbols, which can be seen as an input for various subsequence matching approaches. The variety of data types, specific tasks and their partial or full solutions is so wide that the choice, implementation and parametrization of a suitable solution for a given task might be complicated and time-consuming; a possibly fruitful combination of fragments from different research areas may not be obvious nor easy to realize. The leading authors of this field also mention the implementation bias that makes difficult a proper comparison of competing approaches. Therefore we present a new generic Subsequence Matching Framework (SMF) that tries to overcome the aforementioned problems by a uniform frame that simplifies and speeds up the design, development and evaluation of subsequence matching related systems. We identify several relatively separate subtasks solved differently over the literature and SMF enables to combine them in straightforward manner achieving new quality and efficiency. This framework can be used in many application domains and its components can be reused effectively. Its strictly modular architecture and openness enables also involvement of efficient solutions from different fields, for instance efficient metric-based indexes. This is an extended version of a paper published on DEXA 2012.Comment: This is an extended version of a paper published on DEXA 201

    Availability of pediatric and neonatal intensive care units in the city of São Paulo

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    OBJECTIVE: To describe the health care service provided in pediatric intensive care units in the city of São Paulo, by identifying and describing the units and analyzing their geographic distribution. METHODS: A descriptive cross-sectional study was carried out during a two-year period (August 2000 to July 2002). Data were collected through questionnaires answered by medical directors of each pediatric and neonatal intensive care unit. RESULTS: São Paulo is served by 107 pediatric and neonatal intensive care units, of which 85 (79.4%) completed and returned the questionnaire. We found a very unequal distribution of units as there were more units in places with the least pediatric population. Regarding to pediatric intensive care units specialization, 7% were pediatric, 41.2% were neonatal and 51.7% were mixed (pediatric and neonatal). Regarding hospital funds, 15.3% were associated with philanthropic institutions, 37.6% were private and 47% were public. A total of 1,067 beds were identified, of which 969 were active. The ratio bed/patient aged 0-14 was 1/2,728, varying from 1/604 at health districts - I to 1/6,812 at health districts - III. The units reported an average of 11.7 beds (2 to 60). The neonatal intensive care unit had a median of 16.9 beds per unit and pediatric intensive care units a median of 8.5 beds/unit. CONCLUSION: In São Paulo, we found an uneven distribution of pediatric and neonatal intensive care units among the health districts. There was also an uneven distribution between public and private units, and neonatal and pediatric ones. The current report is the first step in the effort to improve the quality of medical assistance in pediatric and neonatal intensive care units in São Paulo.OBJETIVO: Caracterizar a assistência de saúde prestada em tratamento intensivo pediátrico e neonatal no município de São Paulo através da identificação, descrição e distribuição geográfica das unidades. MÉTODOS: Estudo descritivo, tipo transversal, onde foram estudadas as unidades de terapia intensiva pediátrica e neonatal do município de São Paulo, no período de agosto de 2000 a julho de 2002. A coleta dos dados foi realizada por meio de questionário preenchido pelo coordenador médico de cada unidade. RESULTADOS: Foram listadas 107 unidades de terapia intensiva pediátricas e neonatais no município de São Paulo. Oitenta e cinco (79,4%) unidades forneceram os dados, constituindo a população de estudo. Observou-se maior número de unidades de terapia intensiva em Núcleos Regionais de Saúde com menor população pediátrica. Quanto à faixa etária, 7% eram exclusivamente pediátricas, 41,2% neonatais, e 51,7% mistas. Em relação ao mantenedor: 47% eram públicas, 37,6% privadas, e 15,3% filantrópicas. Identificamos 1.067 leitos, estando 969 em atividade. A razão leito/paciente de 0 a 14 anos foi de 1:2.728, variando de 1:604 (Núcleo Regional de Saúde - I) a 1:6.812 (Núcleo Regional de Saúde - III). O número de leitos por unidade variou de 2 a 60, com média de 11,7 (unidades de terapia intensiva neonatais: 16,9; mistas: 8,5). CONCLUSÃO: No município de São Paulo, observou-se uma distribuição desproporcional das unidades de terapia intensiva pediátrica e neonatal entre os cinco Núcleos Regionais de Saúde. Houve também uma distribuição desproporcional entre unidades de terapia intensiva públicas e privadas e entre neonatais e pediátricas. Esse estudo foi o primeiro esforço na busca por melhor qualidade na assistência intensiva pediátrica e neonatal no município de São Paulo.Universidade de São Paulo Faculdade de MedicinaUniversidade Federal de São Paulo (UNIFESP) Departamento de PediatriaUniversidade de São Paulo Hospital Universitário Unidade de Terapia Intensiva PediátricaUNIFESP, Depto. de PediatriaSciEL

    Choreo: network-aware task placement for cloud applications

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    Cloud computing infrastructures are increasingly being used by network-intensive applications that transfer significant amounts of data between the nodes on which they run. This paper shows that tenants can do a better job placing applications by understanding the underlying cloud network as well as the demands of the applications. To do so, tenants must be able to quickly and accurately measure the cloud network and profile their applications, and then use a network-aware placement method to place applications. This paper describes Choreo, a system that solves these problems. Our experiments measure Amazon's EC2 and Rackspace networks and use three weeks of network data from applications running on the HP Cloud network. We find that Choreo reduces application completion time by an average of 8%-14% (max improvement: 61%) when applications are placed all at once, and 22%-43% (max improvement: 79%) when they arrive in real-time, compared to alternative placement schemes.National Science Foundation (U.S.) (Grant 0645960)National Science Foundation (U.S.) (Grant 1065219)National Science Foundation (U.S.) (Grant 1040072

    The effects of an intronic polymorphism in TOMM40 and APOE genotypes in sporadic inclusion body myositis.

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    A previous study showed that, in carriers of the apolipoprotein E (APOE) genotype ε3/ε3 or ε3/ε4, the presence of a very long (VL) polyT repeat allele in "translocase of outer mitochondrial membrane 40" (TOMM40) was less frequent in patients with sporadic inclusion body myositis (sIBM) compared with controls and associated with a later age of sIBM symptom onset, suggesting a protective effect of this haplotype. To further investigate the influence of these genetic factors in sIBM, we analyzed a large sIBM cohort of 158 cases as part of an International sIBM Genetics Study. No significant association was found between APOE or TOMM40 genotypes and the risk of developing sIBM. We found that the presence of at least 1 VL polyT repeat allele in TOMM40 was significantly associated with about 4 years later onset of sIBM symptoms. The age of onset was delayed by 5 years when the patients were also carriers of the APOE genotype ε3/ε3. In addition, males were likely to have a later age of onset than females. Therefore, the TOMM40 VL polyT repeat, although not influencing disease susceptibility, has a disease-modifying effect on sIBM, which can be enhanced by the APOE genotype ε3/ε3

    Nonlinear and conventional biosignal analyses applied to tilt table test for evaluating autonomic nervous system and autoregulation

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    Copyright © Tseng et al.; Licensee Bentham Open. This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.Tilt table test (TTT) is a standard examination for patients with suspected autonomic nervous system (ANS) dysfunction or uncertain causes of syncope. Currently, the analytical method based on blood pressure (BP) or heart rate (HR) changes during the TTT is linear but normal physiological modulations of BP and HR are thought to be predominately nonlinear. Therefore, this study consists of two parts: the first part is analyzing the HR during TTT which is compared to three methods to distinguish normal controls and subjects with ANS dysfunction. The first method is power spectrum density (PSD), while the second method is detrended fluctuation analysis (DFA), and the third method is multiscale entropy (MSE) to calculate the complexity of system. The second part of the study is to analyze BP and cerebral blood flow velocity (CBFV) changes during TTT. Two measures were used to compare the results, namely correlation coefficient analysis (nMxa) and MSE. The first part of this study has concluded that the ratio of the low frequency power to total power of PSD, and MSE methods are better than DFA to distinguish the difference between normal controls and patients groups. While in the second part, the nMxa of the three stages moving average window is better than the nMxa with all three stages together. Furthermore the analysis of BP data using MSE is better than CBFV data.The Stroke Center and Department of Neurology, National Taiwan University, National Science Council in Taiwan, and the Center for Dynamical Biomarkers and Translational Medicine, National Central University, which is sponsored by National Science Council and Min-Sheng General Hospital Taoyuan

    Cathelicidin suppresses lipid accumulation and hepatic steatosis by inhibition of the CD36 receptor.

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    Background and objectivesObesity is a global epidemic which increases the risk of the metabolic syndrome. Cathelicidin (LL-37 and mCRAMP) is an antimicrobial peptide with an unknown role in obesity. We hypothesize that cathelicidin expression correlates with obesity and modulates fat mass and hepatic steatosis.Materials and methodsMale C57BL/6 J mice were fed a high-fat diet. Streptozotocin was injected into mice to induce diabetes. Experimental groups were injected with cathelicidin and CD36 overexpressing lentiviruses. Human mesenteric fat adipocytes, mouse 3T3-L1 differentiated adipocytes and human HepG2 hepatocytes were used in the in vitro experiments. Cathelicidin levels in non-diabetic, prediabetic and type II diabetic patients were measured by enzyme-linked immunosorbent assay.ResultsLentiviral cathelicidin overexpression reduced hepatic steatosis and decreased the fat mass of high-fat diet-treated diabetic mice. Cathelicidin overexpression reduced mesenteric fat and hepatic fatty acid translocase (CD36) expression that was reversed by lentiviral CD36 overexpression. Exposure of adipocytes and hepatocytes to cathelicidin significantly inhibited CD36 expression and reduced lipid accumulation. Serum cathelicidin protein levels were significantly increased in non-diabetic and prediabetic patients with obesity, compared with non-diabetic patients with normal body mass index (BMI) values. Prediabetic patients had lower serum cathelicidin protein levels than non-diabetic subjects.ConclusionsCathelicidin inhibits the CD36 fat receptor and lipid accumulation in adipocytes and hepatocytes, leading to a reduction of fat mass and hepatic steatosis in vivo. Circulating cathelicidin levels are associated with increased BMI. Our results demonstrate that cathelicidin modulates the development of obesity

    Uniqueness of the potential function for the vectorial Sturm-Liouville equation on a finite interval

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    [[abstract]]In this paper, the vectorial Sturm-Liouville operator L Q =−d 2 dx 2 +Q(x) is considered, where Q(x) is an integrable m×m matrix-valued function defined on the interval [0,π] . The authors prove that m 2 +1 characteristic functions can determine the potential function of a vectorial Sturm-Liouville operator uniquely. In particular, if Q(x) is real symmetric, then m(m+1) 2 +1 characteristic functions can determine the potential function uniquely. Moreover, if only the spectral data of self-adjoint problems are considered, then m 2 +1 spectral data can determine Q(x) uniquely.[[notice]]補正完畢[[incitationindex]]SCI[[cooperationtype]]國外[[booktype]]電子

    Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating Magnetic Field

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    The magnetic behavior of a mixed Ising ferrimagnetic system on a square lattice, in which the two interpenetrating square sublattices have spins +- 1/2 and spins +-1,0, in the presence of an oscillating magnetic field has been studied with Monte Carlo techniques. The model includes nearest and next-nearest neighbor interactions, a crystal field and the oscillating external field. By studying the hysteretic response of this model to an oscillating field we found that it qualitatively reproduces the increasing of the coercive field at the compensation temperature observed in real ferrimagnets, a crucial feature for magneto-optical applications. This behavior is basically independent of the frequency of the field and the size of the system. The magnetic response of the system is related to a dynamical transition from a paramagnetic to a ferromagnetic phase and to the different temperature dependence of the relaxation times of both sublattices.Comment: 10 figures. To be published in Phys.Rev
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