734 research outputs found

    Technical Note: Regularization performances with the error consistency method in the case of retrieved atmospheric profiles

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    International audienceThe retrieval of concentration vertical profiles of atmospheric constituents from spectroscopic measurements is often an ill-conditioned problem and regularization methods are frequently used to improve its stability. Recently a new method, that provides a good compromise between precision and vertical resolution, was proposed to determine analytically the value of the regularization parameter. This method is applied for the first time to real measurements with its implementation in the operational retrieval code of the satellite limb-emission measurements of the MIPAS instrument and its performances are quantitatively analyzed. The adopted regularization improves the stability of the retrieval providing smooth profiles without major degradation of the vertical resolution. In the analyzed measurements the retrieval procedure provides a vertical resolution that, in the troposphere and low stratosphere, is smaller than the vertical field of view of the instrument

    Differential Hox expression in murine embryonic stem cell models of normal and malignant hematopoiesis

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    The Hox family are master transcriptional regulators of developmental processes, including hematopoiesis. The Hox regulators, caudal homeobox factors (Cdx1-4), and Meis1, along with several individual Hox proteins, are implicated in stem cell expansion during embryonic development, with gene dosage playing a significant role in the overall function of the integrated Hox network. To investigate the role of this network in normal and aberrant, early hematopoiesis, we employed an in vitro embryonic stem cell differentiation system, which recapitulates mouse developmental hematopoiesis. Expression profiles of Hox, Pbx1, and Meis1 genes were quantified at distinct stages during the hematopoietic differentiation process and compared with the effects of expressing the leukemic oncogene Tel/PDGFR;2. During normal differentiation the Hoxa cluster, Pbx1 and Meis1 predominated, with a marked reduction in the majority of Hox genes (27/39) and Meis1 occurring during hematopoietic commitment. Only the posterior Hoxa cluster genes (a9, a10, a11, and a13) maintained or increased expression at the hematopoietic colony stage. Cdx4, Meis1, and a subset of Hox genes, including a7 and a9, were differentially expressed after short-term oncogenic (Tel/PDGFR;2) induction. Whereas Hoxa4-10, b1, b2, b4, and b9 were upregulated during oncogenic driven myelomonocytic differentiation. Heterodimers between Hoxa7/Hoxa9, Meis1, and Pbx have previously been implicated in regulating target genes involved in hematopoietic stem cell (HSC) expansion and leukemic progression. These results provide direct evidence that transcriptional flux through the Hox network occurs at very early stages during hematopoietic differentiation and validates embryonic stem cell models for gaining insights into the genetic regulation of normal and malignant hematopoiesis

    Technical note: First spectral measurement of the Earth's upwelling emission using an uncooled wideband Fourier transform spectrometer

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    The first spectral measurement of Earth&apos;s emitted radiation to space in the wideband range from 100 to 1400&nbsp;cm<sup>&minus;1</sup> with 0.5&nbsp;cm<sup>&minus;1</sup> spectral resolution is presented. The measurement was performed from a stratospheric balloon in tropical region using a Fourier transform spectrometer, during a field campaign held in Brazil in June 2005. The instrument, which has uncooled components including the detector module, is a prototype developed as part of the study for the REFIR (Radiation Explorer in the Far InfraRed) space mission. This paper shows the results of the field campaign with particular attention to the measurement capabilities of the prototype. The results are compared with measurements taken by IASI-balloon (Infrared Atmospheric Sounding Interferometer &ndash; Balloon version), aboard the same platform, and with forward model estimations. The infrared signature of clouds is observed in the measurements

    First spectral measurement of the Earth's upwelling emission using an uncooled wideband Fourier transform spectrometer

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    International audienceThe first spectral measurement of Earth's emitted radiation to space in the wideband range from 100 to 1400 cm-1 with 0.5 cm-1 spectral resolution is presented. The measurement was performed from a stratospheric balloon in tropical region using a Fourier transform spectrometer, during a field campaign held in Brazil in June 2005. The instrument, which has uncooled components including the detector module, is a prototype developed as part of the study for the REFIR (Radiation Explorer in the Far InfraRed) space mission. This paper shows the results of the field campaign with particular attention to the measurement capabilities of the prototype. The results are compared with measurements taken by IASI-balloon (Infrared Atmospheric Sounding Interferometer – Balloon version), aboard the same platform, and with forward model estimations. The infrared signature of clouds is observed in the measurements

    Technical note: First spectral measurement of the Earth's upwelling emission using an uncooled wideband Fourier transform spectrometer

    No full text
    International audienceThe first spectral measurement of Earth's emitted radiation to space in the wideband range from 100 to 1400 cm-1 with 0.5 cm-1 spectral resolution is presented. The measurement was performed from a stratospheric balloon in tropical region using a Fourier transform spectrometer, during a field campaign held in Brazil in June 2005. The instrument, which has uncooled components including the detector module, is a prototype developed as part of the study for the REFIR (Radiation Explorer in the Far InfraRed) space mission. This paper shows the results of the field campaign with particular attention to the measurement capabilities of the prototype. The results are compared with measurements taken by IASI-balloon (Infrared Atmospheric Sounding Interferometer – Balloon version), aboard the same platform, and with forward model estimations. The infrared signature of clouds is observed in the measurements

    Compact relaxations for polynomial programming problems

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    Reduced RLT constraints are a special class of Reformulation- Linearization Technique (RLT) constraints. They apply to nonconvex (both continuous and mixed-integer) quadratic programming problems subject to systems of linear equality constraints. We present an extension to the general case of polynomial programming problems and discuss the derived convex relaxation. We then show how to perform rRLT constraint generation so as to reduce the number of inequality constraints in the relaxation, thereby making it more compact and faster to solve. We present some computational results validating our approach

    ESDA2008-59395 LIFECYCLE MONITORING FOR THE AUTOMOTIVE ECO-SUSTAINABILITY

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    ABSTRACT The growth sustainability requires dramatic changes to lower the natural resources consumption and the surroundings pollution, by recovery/remediation processes. The EU policy aims at the extended producers/suppliers responsibility, with effective charges on the products allowed to be put on the market, used and called-back, in view of the properly small impact and transparent lifecycle acknowledgement. This leads to «extensions» in designing the new offers with integrated monitoring and service functions. The design for the lifecycle eco-effectiveness is accomplishment, better qualifying the far-seeing companies according to the EU eco-policy. The idea is to reach the duty visibility, by the extended plug-and-play concept, based on series of integrated design options, assigning the structural and functional modules, for the operation monitoring, the reliability assessment and the impact appraisal. This instrumental setting includes intangible information/communication aids, to confer ambient intelligence abilities. This way, the on-process visibility is assured, and exploited for on-duty servicing and end-of-life processing. The example case chosen deals with the critical situation of the parts manufactured in plastics, which are deemed to represent most relevant portion in the cars to come. The following recovery options are possible: -the reuse of the reconditioned items, according to suitably assessed life-extension opportunities; -the recycling of the warn-out components, with the regeneration and reusing of the materials; -the thermal recovery of residual stuffs, within careful handling and pollution-safe warnings ; -the reduction to registered ASR, automobile shredding residue, within the EU directives limits. The on-board information system includes, as innovative feature, the resort to identifying tags or labels, to be read and written through wireless links. The technology exploits cheap and compact supports, allowing the labelling of the component, from production, to lifecycle, with an identifying code. The RFID, Radio Frequency Identification Device, is privileged, as ideal means for the component traceability and the history, use modes/styles and cumulated issues storing. ACRONYMS ASR, Automobile Shredding Residue. ELV, End-of-Life Vehicle

    Branch and bound based coordinate search filter algorithm for nonsmooth nonconvex mixed-integer nonlinear programming problems

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    Publicado em "Computational science and its applications – ICCSA 2014...", ISBN 978-3-319-09128-0. Series "Lecture notes in computer science", ISSN 0302-9743, vol. 8580.A mixed-integer nonlinear programming problem (MINLP) is a problem with continuous and integer variables and at least, one nonlinear function. This kind of problem appears in a wide range of real applications and is very difficult to solve. The difficulties are due to the nonlinearities of the functions in the problem and the integrality restrictions on some variables. When they are nonconvex then they are the most difficult to solve above all. We present a methodology to solve nonsmooth nonconvex MINLP problems based on a branch and bound paradigm and a stochastic strategy. To solve the relaxed subproblems at each node of the branch and bound tree search, an algorithm based on a multistart strategy with a coordinate search filter methodology is implemented. The produced numerical results show the robustness of the proposed methodology.This work has been supported by FCT (Fundação para a CiĂȘncia e aTecnologia) in the scope of the projects: PEst-OE/MAT/UI0013/2014 and PEst-OE/EEI/UI0319/2014

    Antimicrobial Stewardship Interventions in Pediatric Oncology: A Systematic Review

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    Antimicrobial stewardship programs represent efficacious measures for reducing antibiotic overuse and improving outcomes in different settings. Specific data on pediatric oncology are lacking. We conducted a systematic review on the PubMed and Trip databases according to the PRISMA guidelines, searching for reports regarding antimicrobial stewardship in pediatric oncology and hematology patients. The aim of the study was to summarize the present literature regarding the implementation of antimicrobial stewardship programs or initiatives in this particular population, and provide insights for future investigations. Nine papers were included in the qualitative analysis: three regarding antifungal interventions, five regarding antibacterial interventions, and one regarding both antifungal and antibacterial stewardship interventions. Variable strategies were reported among the included studies. Different parameters were used to evaluate the impact of these interventions, including days of therapy per 1000-patient-days, infections with resistant strains, safety analysis, and costs. We generally observed a reduction in the prescription of broad-spectrum antibiotics and an improved appropriateness, with reduced antibiotic-related side effects and no difference in infection-related mortality. Antibiotic stewardship programs or interventions are effective in reducing antibiotic consumption and improving outcomes in pediatric oncology hematology settings, although stewardship strategies differ substantially in different institutions. A standardized approach needs to be implemented in future studies in order to better elucidate the impact of stewardship programs in this category of patients
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