167 research outputs found

    Third Earth Resources Technology Satellite Symposium. Volume 2: Summary of results

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    Summaries are provided of significant results taken from presentations at the symposium along with some typical examples of the applications of ERTS-1 data for solving resources management problems at the national, state, and local levels

    Third Earth Resources Technology Satellite Symposium. Volume 3: Discipline summary reports

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    Presentations at the conference covered the following disciplines: (1) agriculture, forestry, and range resources; (2) land use and mapping; (3) mineral resources, geological structure, and landform surveys; (4) water resources; (5) marine resources; (6) environment surveys; and (7) interpretation techniques

    An intrinsic exploratory case study: instructors’ and graduate students’ perceptions of community engagement quality factors within a selected hybrid program at a private university

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    This mixed methods exploratory single case study examined instructors' and graduate students' perceptions of the factors that support high quality student engagement in hybrid learning communities in selected doctoral courses at a private university. The purpose of this study was to analyze the graduate student and instructor perceptions of the factors that support high quality student engagement in hybrid learning communities so that a framework for high quality student engagement could be developed. The literature review was designed to review the faculty and student perceptions of the online learning constructs within the engagement theory. These constructs are connected to the quality components of online learning, and the perceptions reflect both student and instructor perceptions of quality. The study showed that instructors and students within the hybrid-learning environment positively perceived the components connected to a quality fully online learning environment. Moreover, the study showed that team building to create a cohesive positive cohort was paramount for students' perceptions of their program. Lastly, the study showed that the role of the instructor was at times constrained in the course due to the pre-loaded content and the role of the student required more ownership to engage the content.Ed.D., Educational Leadership and Management -- Drexel University, 201

    Stochastic modeling and analysis of the bitcoin protocol in the presence of block communication delays

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    International audienceWe analyze the protocol of the Bitcoin blockchain by using the PRISM probabilistic model checker. In particular, we (i) extend PRISM with the ledger data type, (ii) model the behaviour of the key participants in the protocol-the miners-and (iii) describe the whole protocol as a parallel composition of processes. The probabilistic analysis of the model highlights how forks happen and how they depend on specific parameters of the protocol, such as the difficulty of the cryptopuzzle and the network communication delays. Our results confirm that considering transactions in blocks at depth larger than 5 as permanent is reasonable because the majority of miners have consistent blockchains up-to that depth with probability of almost 1. We also study the behaviour of networks with churn miners, which may leave the network and rejoin afterwards, and with different topologies

    Scanning tunneling microscopy of deoxyribonucleic acid during replication

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    Scanning tunneling microscopy was used to produce topographic images of uncoated and unlabeled deoxyribonucleic acid (DNA) in air, on a graphite substrate. The images show for the first time a DNA molecule that had been isolated while it was replicating

    Does the term 'trophic' actually mean anti-amyloidogenic? The case of NGF.

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    The term trophic is widely used to indicate a general pro-survival action exerted on target cells by different classes of extracellular messengers, including neurotrophins (NTs), a family of low-molecular-weight proteins whose archetypal member is the nerve growth factor (NGF). The pro-survival action exerted by NTs results from a coordinated activation of multiple metabolic pathways, some of which have only recently come to light. NGF has been shown to exert a number of different, experimentally distinguishable effects on neurons, such as survival, differentiation of target neurons, growth of nerve fibers and their guidance (tropism) toward the source of its production. We have proposed a more complete definition of the NGF trophic action that should also include its newly discovered property of inhibiting the amyloidogenic processing of amyloid precursor protein (APP), which is among the first hypothesized primary trigger of Alzheimer's disease (AD) pathogenesis. This inhibitory action appears to be mediated by a complex series of molecular events and by interactions among NGF receptors (TrkA and p75), APP processing and tau metabolic fate and fun

    Influencia del contenido graso y de otras variables sobre la capacidad de fusión del queso Cremoso Argentino

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    The influence of the fat content, pH, the ripening degree and the incorporation of whey proteins, by two different methods, on the meltability of Cremoso Argentino cheese was examined. Different experimental cheeses were made at pilot plant scale and their meltabilities were determined by a modified Schreiber test. Ripening degree and fat content showed a good correlation with the meltability. Though, cheeses with incorporation of whey proteins showed poor meltability, despite their yields increased. No correlation was found between pH and meltability inside the pH working range studied.En el presente trabajo se estudió la influencia del contenido de materia grasa, pH, grado de maduración e incorporación de proteínas de suero mediante dos vías diferentes sobre la capacidad de fusión del queso Cremoso Argentino. Utilizando una técnica modificada del test de Schreiber se analizó la capacidad de fusión de distintos quesos experimentales elaborados a escala piloto. El contenido graso y el grado de maduración afectaron positivamente la capacidad de fusión. La incorporación de proteínas de suero produjo mayores rendimientos pero la capacidad de fusión se vio fuertemente disminuida. No se observó una influencia clara del pH dentro de los límites estudiado

    Effects of PPARγ agonists on the expression of leptin and vascular endothelial growth factor in breast cancer cells.

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    The obesity hormone leptin has been implicated in breast cancer development. Breast cancer cells express the leptin receptor and are able to synthesize leptin in response to obesity-related stimuli. Furthermore, leptin is a positive regulator of vascular endothelial growth factor (VEGF) and high levels of both proteins are associated with worse prognosis in breast cancer patients. Peroxisome proliferator-activated receptor (PPAR) ligands are therapeutic agents used in patient with Type 2 diabetes and obesity which have recently been studied for their potential anti-tumor effect. Here, we studied if these compounds, ciglitazone and GW1929, can affect the expression of leptin and VEGF in breast cancer cells. In MDA-MB-231 and MCF-7 breast cancer cells, treatment with submolar concentrations of ciglitazone and GW1929 elevated the expression of leptin and VEGF mRNA and protein, and increased cell viability and migration. These effects coincided with increased recruitment of PPAR to the proximal leptin promoter and decreased association of a transcriptional factor Sp1 with this DNA region
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