383 research outputs found
Erratum: Small-world networks: Evidence for a crossover picture
We correct the value of the exponent \tau.Comment: 2 pages, 1 figur
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Macro-level Modeling of the Response of <i>C. elegans</i> Reproduction to Chronic Heat Stress
A major goal of systems biology is to understand how organism-level behavior arises from a myriad of molecular interactions. Often this involves complex sets of rules describing interactions among a large number of components. As an alternative, we have developed a simple, macro-level model to describe how chronic temperature stress affects reproduction in C. elegans. Our approach uses fundamental engineering principles, together with a limited set of experimentally derived facts, and provides quantitatively accurate predictions of performance under a range of physiologically relevant conditions. We generated detailed time-resolved experimental data to evaluate the ability of our model to describe the dynamics of C. elegans reproduction. We find considerable heterogeneity in responses of individual animals to heat stress, which can be understood as modulation of a few processes and may represent a strategy for coping with the ever-changing environment. Our experimental results and model provide quantitative insight into the breakdown of a robust biological system under stress and suggest, surprisingly, that the behavior of complex biological systems may be determined by a small number of key components.</p
On the nature of the (de)coupling of the magnetostructural transition in ErSi
In this report, a successful thermodynamical model was employed to understand
the structural transition in ErSi, able to explain the decoupling of
the magnetic and structural transition. This was achieved by the DFT
calculations which were used to determine the energy differences at 0 K, using
a LSDA+U approximation. It was found that the M structure as the stable phase
at low temperatures as verified experimentally with a 0.262 eV.
Finally, it was achieved a variation of Seebeck coefficient ( 6 V)
at the structural transition which allow to conclude that the electronic
entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl
The MIDAS telescope for microwave detection of ultra-high energy cosmic rays
We present the design, implementation and data taking performance of the
MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view
imaging telescope designed to detect microwave radiation from extensive air
showers induced by ultra-high energy cosmic rays. This novel technique may
bring a tenfold increase in detector duty cycle when compared to the standard
fluorescence technique based on detection of ultraviolet photons. The MIDAS
telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera,
instrumented with feed horns operating in the commercial extended C-Band (3.4
-- 4.2 GHz). A self-trigger capability is implemented in the digital
electronics. The main objectives of this first prototype of the MIDAS telescope
- to validate the telescope design, and to demonstrate a large detector duty
cycle - were successfully accomplished in a dedicated data taking run at the
University of Chicago campus prior to installation at the Pierre Auger
Observatory.Comment: 13 pages, 18 figure
Prothrombin G20210A gene mutation, factor V Leiden and anticardiolipin antibodies do not influence renal graft survival after transplantation
INTRODUCTION: Thromboembolic complications are important risk factors for graft failure and worse renal transplantation outcome. Patients with thrombophilic disorders have a higher risk of thromboembolic complications. The prevalence of thrombophilic disorders and the associated risk for graft failure and for intravascular thrombosis were analyzed in renal transplant recipients. METHODS: This is a cohort study of 388 adult recipients investigated regarding the presence of thrombophilia, through the search for anticardiolipin antibodies (aCL) via ELISA and FV G1691A and PT G20210A gene mutations by multiplex PCR. RESULTS: Thrombophilic disorders were identified in 25.8% of the patients. The 2-year graft survival was similar among patients with and without thrombophilic disorder (94% versus 94%, p = 0.53), and so was the survival free of intravascular thrombosis (97% versus 97%, p = 0.83). The prevalence of intravascular thrombosis was similar in both groups (3% versus 3.5%, p = 0.82). Patients with previous kidney transplantation had a higher risk of graft failure (OR 20.8, p < 0.001) and of intravascular thrombosis (OR 6.8, p = 0.008). CONCLUSIONS: The prevalences of FV G1691A and PT G20210A gene mutations in this cohort of patients were similar to those of the general non-transplanted population. The prevalence of aCL antibodies was higher in this cohort than that observed in healthy individuals. The thrombophilic markers studied did not predict the medium-term survival of renal transplant.INTRODUÇÃO: Complicações tromboembólicas são importantes fatores de risco para perda do enxerto e pior evolução após o transplante renal. Pacientes com defeito trombofílico apresentam maior risco de complicações tromboembólicas. Foram analisados, entre receptores de transplante renal, a prevalência de defeito trombofílico e o risco atribuído a esta condição para a perda do enxerto e para o desenvolvimento de tromboses intravasculares. MÉTODOS: Estudo do tipo coorte incluindo 388 receptores adultos analisados quanto à presença de trombofilia de acordo com a pesquisa de anticorpos anticardiolipina (aCL) por ELISA e das mutações G1691A no gene do fator V (FV) e G20210A no gene da protrombina (PT) por PCR multiplex. RESULTADOS: Defeito trombofílico foi identificado em 25,8% dos pacientes. As taxas de sobrevida de 2 anos do enxerto foram semelhantes entre os pacientes com e sem defeito trombofílico (94% versus 94%, p = 0,53), bem como a sobrevida dos enxertos livres de tromboses intravasculares (97% versus 97%, p = 0,83). Pacientes com defeito trombofílico apresentaram prevalência de tromboses intravasculares semelhante à do grupo-controle (3% versus 3,5%, p = 0,82). O transplante renal anterior foi associado a maior risco de perda de enxerto (OR 20,8, p < 0,001) e de ocorrência de tromboses intravasculares (OR 6,8, p = 0,008). CONCLUSÕES: As prevalências das mutações FV G1691A e PT G20210A na população estudada foram semelhantes às da população geral não transplantada, e a prevalência de anticorpos aCL superou a observada entre os indivíduos sadios. Não houve associação entre os marcadores de trombofilia estudados e a sobrevida em médio prazo do transplante renal.UNIFESP Departamento de Medicina, Disciplina de HematologiaUNIFESP Departamento de Medicina, Disciplina de NefrologiaUNIFESP Departameto de Medicina, Disciplina de ReumatologiaUNIFESP Departamento de Medicina Preventiva, Disciplina de BioestatísticaUniversidad de Antofagasta Departamento de Tecnologia MedicaUNIFESP, Depto. de Medicina, Disciplina de HematologiaUNIFESP, Depto. de Medicina, Disciplina de NefrologiaUNIFESP, Departameto de Medicina, Disciplina de ReumatologiaUNIFESP, Depto. de Medicina Preventiva, Disciplina de BioestatísticaSciEL
ESMO Clinical Research Observatory (ECRO): improving the efficiency of clinical research through rationalisation of bureaucracy
During the last years, there has been a dramatic increase in the administrative and bureaucratic burden associated with cli
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