25 research outputs found

    National Geotechnical Experimentation Sites: Central Data Repository (User Manual)

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    DTFH61-90-R-00081The National Science Foundation (NSF) and the Federal Highway Administration (FHWA) recently set up a system of National Geotechnical Experimentation Sites (NGES) available to the geotechnical community at-large for the purpose of advancing the state of the art in such areas as in situ testing, field instrumentation, and prediction of soil behavior. As part of this program, the FHWA also funded the creation of a data base to document the activities and results at each test site. This report describes a data base system, the National Geotechnical Experimentation Sites Data Base (NGESDB) which stores site information and geotechnical data from the experimentation sites. NGESDB allows the user to select a site by soil type, State, or geotechnical activity. Once a site is selected, the NGESDB can be used to display site information such as the site description, representative soil properties, boring locations, owner and contact information, and references with abstracts. Geotechnical data is available for several laboratory and in situ tests as well, including test information details and complete results for each test. Descriptions of prototype and model foundations, permanent field instrumentation, and site improvement activities at each site are also included

    Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna

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    The random superposition of many weak sources will produce a stochastic background of gravitational waves that may dominate the response of the LISA (Laser Interferometer Space Antenna) gravitational wave observatory. Unless something can be done to distinguish between a stochastic background and detector noise, the two will combine to form an effective noise floor for the detector. Two methods have been proposed to solve this problem. The first is to cross-correlate the output of two independent interferometers. The second is an ingenious scheme for monitoring the instrument noise by operating LISA as a Sagnac interferometer. Here we derive the optimal orbital alignment for cross-correlating a pair of LISA detectors, and provide the first analytic derivation of the Sagnac sensitivity curve.Comment: 9 pages, 11 figures. Significant changes to the noise estimate

    All-particle cosmic ray energy spectrum measured with 26 IceTop stations

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    We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 surface stations operational at that time, corresponding to about one third of the final array. The fiducial area used in this analysis was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV measured for three different zenith angle ranges between 0{\deg} and 46{\deg}. Because of the isotropy of cosmic rays in this energy range the spectra from all zenith angle intervals have to agree. The cosmic-ray energy spectrum was determined under different assumptions on the primary mass composition. Good agreement of spectra in the three zenith angle ranges was found for the assumption of pure proton and a simple two-component model. For zenith angles {\theta} < 30{\deg}, where the mass dependence is smallest, the knee in the cosmic ray energy spectrum was observed between 3.5 and 4.32 PeV, depending on composition assumption. Spectral indices above the knee range from -3.08 to -3.11 depending on primary mass composition assumption. Moreover, an indication of a flattening of the spectrum above 22 PeV were observed.Comment: 38 pages, 17 figure

    Keep calm and carry on: miRNA biogenesis under stress

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    MicroRNAs (miRNAs) are major post-transcriptional regulators of gene expression. Their biogenesis relies on the cleavage of longer precursors by a nuclear localized processing machinery. The evolutionary preference of plant miRNAs to silence transcription factors turned these small molecules into key actors during growth and adaptive responses. Furthermore, during their life cycle plants are subject to changes in the environmental conditions surrounding them. In order to face these changes, plants display unique adaptive capacities based on an enormous developmental plasticity, where miRNAs play central roles. Many individual miRNAs have been shown to modulate the plant response to different environmental cues and stresses. In the last few years, increasing evidence has shown that not only individual genes encoding miRNAs but also the miRNA pathway as a whole is subject to regulation in response to external stimulus. In this review, we discuss the current knowledge about the miRNA pathway. We dissect the pathway to analyze the events leading to the generation of these small RNAs and emphasize the regulation of core components of the miRNA biogenesis machinery.Fil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Yang, Seong W.. Yonsei University; Corea del SurFil: Palatnik, Javier Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin

    Propriedades de solos sob vegetação nativa em Minas Gerais: distribuição por fitofisionomia, hidrografia e variabilidade espacial

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    A distribuição das formações vegetais nativas depende dos fatores de formação do solo, entre outros aspectos. Dessa forma, solos sob vegetação nativa podem informar muito sobre uma região e sua fertilidade natural, constituindo um testemunho das condições encontradas antes da ocupação agrossilvopastoril. O objetivo deste estudo foi avaliar propriedades químicas e textura dos solos sob fragmentos de Cerrado e florestas nativas amostrados durante o Inventário Florestal de Minas Gerais, por meio de análises de fertilidade do solo, textura e estatística espacial. Em geral, houve grande variabilidade em todas as propriedades analisadas, exceto em Al trocável. Os solos sob Campo Cerrado apresentaram maiores teores de matéria orgânica, comparados aos sob Cerradão e Cerrado stricto sensu. As Florestas Estacionais ocorreram, em geral, em solos de melhor fertilidade natural do que aqueles sob Cerrado, enquanto as florestas sob clima chuvoso ocorreram nos solos mais ácidos e com maiores teores de matéria orgânica, entre todas as fitofisionomias. Análises de regressão linear indicaram que a importância da matéria orgânica na CTC a pH 7,0 variou entre as diferentes fitofisionomias, sendo não significativa para as Florestas Deciduais. A estratificação por bacias hidrográficas, interpretada em conjunto com a fitofisionomia, permitiu também concluir sobre um provável efeito dos materiais de origem nas propriedades do solo, especialmente a textura. Por meio de análise geoestatística, foi possível construir, por krigagem ordinária, mapas do Estado com a distribuição de teores de carbono orgânico do solo, argila e pH, mas não para CTC a pH 7,0. A análise de solos sob fragmentos de vegetação nativa oferece potencial para uso como referência do padrão de fertilidade natural dos solos e é uma iniciativa que poderia ser empreendida em outras unidades da federação

    A Cluster Randomized Controlled Trial of the Archena Infancia Saludable Project on 24-h Movement Behaviors and Adherence to the Mediterranean Diet among Schoolchildren: a Pilot Study Protocol

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    Objective: The aim of this paper is to describe the protocol of pilot cluster randomized controlled trial (RCT) that will evaluate the effects of a lifestyle-based intervention. The Archena Infancia Saludable project will have several objectives. The primary objective of this project is to determine the 6-month effects of a lifestyle-based intervention on adherence to 24-h movement behaviors and Mediterranean diet (MedDiet) in schoolchildren. The secondary objective of this project is to test the intervention effects of this lifestyle-based intervention on a relevant set of health-related outcomes (i.e., anthropometric measurements, blood pressure, perceived physical fitness, sleep habits, and academic performance). The tertiary objective is to investigate this intervention's halo effect on parents'/guardians' 24-h movement behaviors and adherence to the MedDiet. Methods: The Archena Infancia Saludable trial will be a cluster RCT submitted to the Clinical Trials Registry. The protocol will be developed according to SPIRIT guidelines for RCTs and CONSORT statement extension for cluster RCTs. A total of 153 eligible parents/guardians with schoolchildren aged 6-13 years will be randomized into an intervention group or a control group. This project focuses on two fundamental pillars: 24-h movement behaviors and MedDiet. It will mainly focus on the relationship between parents/guardians and their children. Behavior change strategies for dietary and 24-h movement behaviors in schoolchildren will be based on healthy lifestyle education for parents/guardians through infographics, video recipes, brief video clips, and videos. Conclusions: Most of the current knowledge on 24-h movement behaviors and adherence to the MedDiet is based on cross-sectional or longitudinal cohort studies, warranting a need to design and conduct RCTs to obtain more robust evidence on the effect of a healthy lifestyle program to increase 24-h movement behaviors and to improve adherence to the MedDiet in schoolchildren
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