745 research outputs found

    Off-nadir antenna bias correction using Amazon rain forest sigma deg data

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    The radar response from the Amazon rain forest was studied to determine the suitability of this region for use as a standard target to calibrate a scatterometer like that proposed for the National Ocean Satellite System (NOSS). Backscattering observations made by the SEASAT-1 scatterometer system show the Amazon rain forest to be a homogeneous, azimuthally-isotropic, radar target which is insensitive to polarization. The variation with angle of incidence may be adequately modeled as sigma deg (dB) = alpha theta + beta with typical values for the incidence-angle coefficient from 0.07 dB deg to 0.15 dB/deg. A small diurnal effect occurs, with measurements at sunrise being 0.5 dB to 1 dB higher than the rest of the day. Maximum likelihood estimation algorithms are presented which permit determination of relative bias and true pointing angle for each beam. Specific implementation of these algorithms for the proposed NOSS scatterometer system is also discussed

    Targeting NaPi2b in ovarian cancer.

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    Novel biomarkers are needed to direct new treatments for ovarian cancer, a disease for which the standard of care remains heavily focused on platinum-based chemotherapy. Despite the success of PARP inhibitors, treatment options are limited, particularly in the platinum-resistant setting. NaPi2b is a cell surface sodium-dependent phosphate transporter that regulates phosphate homeostasis under normal physiological conditions and is a lineage marker that is expressed in select cancers, including ovarian, lung, thyroid, and breast cancers, with limited expression in normal tissues. Based on its increased expression in ovarian tumors, NaPi2b is a promising candidate to be studied as a biomarker for treatment and patient selection in ovarian cancer. In preclinical studies, the use of antibodies against NaPi2b showed that this protein can be exploited for tumor mapping and therapeutic targeting. Emerging data from phase 1 and 2 clinical trials in ovarian cancer have suggested that NaPi2b can be successfully detected in patient biopsy samples using immunohistochemistry, and the NaPi2b-targeting antibody-drug conjugate under evaluation appeared to elicit therapeutic responses. The aim of this review is to examine literature supporting NaPi2b as a novel biomarker for potential treatment and patient selection in ovarian cancer and to discuss the critical next steps and future analyses necessary to drive the study of this biomarker and therapeutic targeting forward

    On the predictability of ice avalanches

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    The velocity of unstable large ice masses from hanging glaciers increases as a power-law function of time prior to failure. This characteristic acceleration presents a finite-time singularity at the theoretical time of failure and can be used to forecast the time of glacier collapse. However, the non-linearity of the power-law function makes the prediction difficult. The effects of the non-linearity on the predictability of a failure are analyzed using a non-linear regression method. Predictability strongly depends on the time window when the measurements are performed. Log-periodic oscillations have been observed to be superimposed on the motion of large unstable ice masses. The value of their amplitude, frequency and phase are observed to be spatially homogeneous over the whole unstable ice mass. Inclusion of a respective term in the function describing the acceleration of unstable ice masses greatly increases the accuracy of the prediction

    Gestão de políticas públicas: análise do plano nacional de promoção das cadeias de produtos da sociobiodiversidade.

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    Esta pesquisa objetiva analisar a elaboração do Plano Nacional de Promoção das Cadeias de Produtos da Sociobiodiversidade - PNPSB a partir da metodologia proposta por Dagnino (2013). Com levantamento de documentos, foi possível analisar o PNPSB com a metodologia proposta nas etapas de elaboração, implantação e avaliação do Plano

    Avaliação comparative de propriedades de uma cerâmica à base de argila conformada por quatro técnicas

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    The results of qualitative and quantitative properties of clay based ceramic are presented in this work. Four different shaping methods and sintering temperatures were used to understand their influence in the final properties of a ceramic material formulated using kaolinite clay and calcined alumina. This material can be used as a structural ceramic for different applications, and there is no pre-established relation between the forming method and the final sintered properties. Forming methods used to prepare the samples were uniaxial pressing (a batch process that allows application in dry samples), extruding (a continuous process that requires moisture), slip casting (a process that allows to shape complex ceramic ware), and lamination (a batch process that requires moisture). Sintering temperatures were in the range of 1100 and 1400 °C. In order to compare how properties behave as the shaping method and sintering temperature change, textural properties, shrinkage, porosimetry, phase composition and mechanical strength were evaluated and analyzed. Scanning electron microscopy and microtomography were employed for analyzing and comparing the developed microstructures. Differences in the resulting properties are explained in terms of the developed crystalline phases and microstructure.Resultados das propriedades qualitativas e quantitativas de cerâmica à base de argila são apresentados neste trabalho. Foram utilizados quatro diferentes métodos de conformação e temperaturas de sinterização para entender suas influências nas propriedades finais de um material cerâmico formulado usando argila caulinítica e alumina calcinada. Este material pode ser usado como cerâmica estrutural para diferentes aplicações, e não há relação pré-estabelecida entre o método de conformação e as propriedades sinterizadas finais. Os métodos de conformação utilizados para preparar as amostras foram prensagem uniaxial (processo em batelada que permite a aplicação em amostras secas), extrusão (processo contínuo que requer umidade), colagem (processo que permite moldar produtos cerâmicos complexos) e laminação (processo em batelada que requer umidade). As temperaturas de sinterização foram na faixa de 1100 e 1400 °C. Para comparar como as propriedades se comportam à medida que o método de moldagem e a temperatura de sinterização são alterados, as propriedades de textura, retração, porosimetria, composição de fases e resistência mecânica foram avaliadas e analisadas. Microscopia eletrônica de varredura e microtomografia foram empregadas para analisar e comparar as microestruturas desenvolvidas. As diferenças nas propriedades resultantes são explicadas em termos das fases cristalinas desenvolvidas e da microestrutura.Fil: Torres, Camila Irene. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Rendtorff Birrer, Nicolás Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; ArgentinaFil: Cipollone, M.. YPF - Tecnología; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aglietti, Esteban Fausto. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; ArgentinaFil: Suarez, Gustavo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentin

    Pushing the Limits of Detectability: Mixed Dark Matter from Strong Gravitational Lenses

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    One of the frontiers for advancing what is known about dark matter lies in using strong gravitational lenses to characterize the population of the smallest dark matter halos. There is a large volume of information in strong gravitational lens images -- the question we seek to answer is to what extent we can refine this information. To this end, we forecast the detectability of a mixed warm and cold dark matter scenario using the anomalous flux ratio method from strong gravitational lensed images. The halo mass function of the mixed dark matter scenario is suppressed relative to cold dark matter but still predicts numerous low-mass dark matter halos relative to warm dark matter. Since the strong lens signal is a convolution over a range of dark matter halo masses and since the signal is sensitive to the specific configuration of dark matter halos, not just the halo mass function, degeneracies between different forms of suppression in the halo mass function, relative to cold dark matter, can arise. We find that, with a set of lenses with different configurations of the main deflector and hence different sensitivities to different mass ranges of the halo mass function, the different forms of suppression of the halo mass function between the warm dark matter model and the mixed dark matter model can be distinguished with 4040 lenses with Bayesian odds of 29.4:1.Comment: 8 pages, 7 figure

    Deep, noninvasive imaging and surgical guidance of submillimeter tumors using targeted M13-stabilized single-walled carbon nanotubes

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    Highly sensitive detection of small, deep tumors for early diagnosis and surgical interventions remains a challenge for conventional imaging modalities. Second-window near-infrared light (NIR2, 950–1,400 nm) is promising for in vivo fluorescence imaging due to deep tissue penetration and low tissue autofluorescence. With their intrinsic fluorescence in the NIR2 regime and lack of photobleaching, single-walled carbon nanotubes (SWNTs) are potentially attractive contrast agents to detect tumors. Here, targeted M13 virus-stabilized SWNTs are used to visualize deep, disseminated tumors in vivo. This targeted nanoprobe, which uses M13 to stably display both tumor-targeting peptides and an SWNT imaging probe, demonstrates excellent tumor-to-background uptake and exhibits higher signal-to-noise performance compared with visible and near-infrared (NIR1) dyes for delineating tumor nodules. Detection and excision of tumors by a gynecological surgeon improved with SWNT image guidance and led to the identification of submillimeter tumors. Collectively, these findings demonstrate the promise of targeted SWNT nanoprobes for noninvasive disease monitoring and guided surgery.National Institutes of Health (U.S.). Center for Nanotechnology Excellence (Grant U54-CA119349-04)National Institutes of Health (U.S.). Center for Nanotechnology Excellence (Grant U54-CA151884)David H. Koch Institute for Integrative Cancer Research at MIT. Frontier Research Program (Kathy and Curt Marble Cancer Research Fund)National Institute of Environmental Health Sciences (Grant P30-ES002109)Marie D. & Pierre Casimir-Lambert FundAmar G. Bose Research Gran

    Biodiversität im Kulturland – vom Nebenprodukt zum Marktvorteil

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    Zusammenfassung Die in der Schweiz getroffenen Maßnahmen gegen den Rückgang der Biodiversität im Kulturland zeigen wenig Erfolg. Die Gründe dürften einerseits in der gängigen Subventionspolitik, andererseits beim ökologischen Wissen der Landwirte liegen. Das 2008 gestartete Projekt „Mit Vielfalt punkten – Bauern beleben die Natur“ will an diesen beiden Punkten ansetzten. Vorerst wurde ein Punktesystem entwickelt, mit dem die Leistungen der Betriebe für die Biodiversität ermittelt werden können. Der Zusammenhang Punkte – Biodiversität wird geprüft. In Zukunft werden 30 Betriebe intensiv mit dem Ziel beraten, dass mehr Maßnahmen zu Gunsten der Biodiversität umgesetzt werden. Für die Beratung werden Leitartenkarten entwickelt, denn es hat sich gezeigt, dass Landwirte besser auf konkrete Arten ansprechen als auf theoretische Konzepte. Die Auswirkungen der Beratung werden geprüft, sowohl auf der Ebene Biodiversität als auch auf der sozio-ökonomischen Ebene. Bereits zu Beginn des Projektes hat die IP-SUISSE (Verein der integriert produzierenden Landwirte) das Punktesystem in ihre Richtlinien aufgenommen und mit einer Mindestpunktezahl versehen. Die Migros (Vermarkter) übernimmt einen großen Teil dieser Produkte und zahlt den Landwirten einen Bonus aus. Sie gibt die Produkte unter dem Label TerraSuisse den Konsumierenden weiter. So wird die Biodiversität zu einem Marktfaktor

    Flash sintering of zircon: rapid consolidation of an ultrahigh bandgap ceramic

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    Zircon (ZrSiO4) is a refractory structural ceramic material difficult to consolidate because of its thermal dissociation into ZrO2 and SiO2. Addition of sintering aids can improve its densification, but with detrimental effects on high temperature mechanical properties and corrosion resistance. In this work, zircon was consolidated by employing the Flash Sintering (FS) technique at a furnace temperature of 1250°C under an electrical field of 1000 V cm−1. The decomposition of zircon was significantly reduced by lowering sintering time and current density. Unlike conventional sintering methods, FS approach allowed to track the degree of dissociation by measuring the electrical resistivity, providing a promising route for the consolidation of such materials. Although the obtained zircon ceramics are characterized by lower density and hardness/toughness than those sintered by alternative advanced techniques (like SPS of HEBM activated powders), the consolidation can be carried out at remarkably reduced furnace temperature.Fil: Martinez, Juan Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Biesuz, Mattia. Universita degli Studi di Trento; ItaliaFil: Dong, Jian. Southwest Jiaotong University; ChinaFil: Gauna, Matias Roberto. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Suarez, Gustavo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Sglavo, Vincenzo M.. Universita degli Studi di Trento; ItaliaFil: Lin, HuaTay. Guangdong University of Technology; ChinaFil: Grasso, Salvatore. Southwest Jiaotong University; ChinaFil: Rendtorff Birrer, Nicolás Maximiliano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin
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