6,071 research outputs found

    Far-infrared measurements of trace gases

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    A better detector system was developed for far infrared spectroscopy by usng cryogenic technology to cool bolometric detectors to approximately 0.4K. Technical assistance was provided to two submillimeter infrared balloon experiment (SIBEX) flights which demonstrated the diagnostic capability of far IR emission spectroscopy. It is estimated that more than a hundred spectral emission features were detected which are not due to the main emitting gases O3, O2, and H2O. The trace species sources for many features still remain unidentified and the spectra obtained during the SIBEX flights present a new source of information on stratospheric composition

    Commitment or Control? Human Resource Management Practices in Female and Male-Led Businesses

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    This paper investigates the commitment-orientation of HRM practices in female- and male-led firms. A distinction is made between emphasizing commitment or control in the design of HRM practices. To test for gender differences use is made of a sample of 555 Dutch firms. Contrary to what is generally believed it is found that ñ€“ when controlled for relevant factors related to the business (e.g., firm size, age, sector) ñ€“ HRM in female-led firms is more control-oriented than that in male-led firms. More specifically, female-led firms are more likely to be characterized by fixed and clearly defined tasks, centralized decision-making and direct supervision of the production process.entrepreneurship;gender;human resource management;commitment;control

    Blends of Nitrile Butadiene Rubber/poly (Vinyl Chloride): the Use of Maleated Anhydride Castor Oil Based Plasticizer

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    Recently, much attention has been focused on research to replace petroleum-based plasticizers, with biodegradable materials, such as biopolymer which offers competitive mechanical properties. In this study, castor oil was modified with maleic anhydride (MAH) to produce bioplasticizer named maleated anhydride castor oil (MACO), and used in nitrile butadiene rubber (NBR)/poly vinyl chloride (PVC) blend. The effect of MACO on its cure characteristics and mechanical properties of NBR/PVC blend has been determined. The reactions were carried out at different castor oil (CO)/xylene ratios, i.e. 1:0 and 1:1 by weight, and fixed CO/MAH ratio, 1:3 by mole. DOP, CO, and MACO were added into each NBR/PVC blend according to the formula. It was found that the viscosity and safe process level of NBR/PVC blend is similar from all plasticizer, however, MACO (1:0) showed the highest cure rate index (CRI). MACO-based plasticizer gave a higher value of the mechanical properties of the NBR/PVC blend as compared to DOP based plasticizer. MACO (1:1) based plasticizer showed a rather significance performance compared to another type of plasticizers both before and after aging. The value of hardness, elongation at break, tensile strength, and tear strength were 96 Shore A, 155.91 %, 19.15 MPa, and 74.47 MPa, respectively. From this result, NBR/PVC blends based on MACO plasticizer can potentially replace the DOP, and therefore, making the rubber blends eco-friendly

    Taxonomic revision of the genus Alternanthera (Amaranthaceae) in Italy

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    A taxonomic revision of the genus Alternanthera (Amaranthaceae) in Italy is here presented. Field surveys were carried out during the period 2007–2013. Thirty-six herbaria (both European and American) were consulted as well as extensive literature was analyzed. Four taxa are recognized, all of them to be considered aliens native to South America. Information about nomenclature (accepted names, main synonyms, and types), morphology, chromosome number, alien status (at national and regional levels), occurrence in Italy (at regional and provincial scale), ecology (preferential habitat, phenology, and elevation), taxonomical notes, and Italian vernacular names were provided for each taxon. A diagnostic key was given. For the nomenclatural purposes the generic name Alternanthera and its type was discussed, and the names A. paronychioides and A. pungens were studied and typified (lecto- and neotype, respectively) on specimens preserved at PH and P

    Distributed Average Consensus under Quantized Communication via Event-Triggered Mass Summation

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    We study distributed average consensus problems in multi-agent systems with directed communication links that are subject to quantized information flow. The goal of distributed average consensus is for the nodes, each associated with some initial value, to obtain the average (or some value close to the average) of these initial values. In this paper, we present and analyze a distributed averaging algorithm which operates exclusively with quantized values (specifically, the information stored, processed and exchanged between neighboring agents is subject to deterministic uniform quantization) and relies on event-driven updates (e.g., to reduce energy consumption, communication bandwidth, network congestion, and/or processor usage). We characterize the properties of the proposed distributed averaging protocol on quantized values and show that its execution, on any time-invariant and strongly connected digraph, will allow all agents to reach, in finite time, a common consensus value represented as the ratio of two integer that is equal to the exact average. We conclude with examples that illustrate the operation, performance, and potential advantages of the proposed algorithm

    The Italian Office Desk: ‘Mass production and one-off piece’ towards the modernity / El escritorio de la oficina italiana: “La producciĂłn en masa y la pieza Ășnica” hacia la modernidad

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    In Italy the history of modern equipment design has shifted between ‘mass production and one-off’, as architects Gio Ponti and Antonio Fornaroli wrote in an article in the magazine Domus (1948). Starting from this important reflection by the two Italian architects, the article takes into consideration the case study of office furniture. The aim of the article is to identify the cultural landscape of Italian design during the twentieth century, taking into consideration the example of the office desk as fil rouge of the history of design in Italy. The methodology adopted is deductive: starting from the selection of some case studies (desks designed for some elitist furnishings or, vice versa, for serial reproduction) and in relation to the architectural and cultural context in which they were created, some key concepts are deduced in order to understand the progressive adherence of Italian architects to the idea of modernity, and then to the massification of industrial design. New materials and ancient ‘know-how’ have merged into projects that have distinguished the history of design in Italy as original. The conclusion highlights how in the history of Italian office furniture as a multi-faceted history, where elite furniture can become a democratic product, until it becomes part of the contemporary office

    Reweighting NNPDFs: the W lepton asymmetry

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    We present a method for incorporating the information contained in new datasets into an existing set of parton distribution functions without the need for refitting. The method involves reweighting the ensemble of parton densities through the computation of the chi-square to the new dataset. We explain how reweighting may be used to assess the impact of any new data or pseudodata on parton densities and thus on their predictions. We show that the method works by considering the addition of inclusive jet data to a DIS+DY fit, and comparing to the refitted distribution. We then use reweighting to determine the impact of recent high statistics lepton asymmetry data from the D0 experiment on the NNPDF2.0 parton set. We find that the D0 inclusive muon and electron data are perfectly compatible with the rest of the data included in the NNPDF2.0 analysis and impose additional constraints on the large-x d/u ratio. The more exclusive D0 electron datasets are however inconsistent both with the other datasets and among themselves, suggesting that here the experimental uncertainties have been underestimated.Comment: 36 pages, 22 figures: errors in Eqns.12,36,37 corrected and parts of Figs.1,6,10,13,15,19 replace

    From early stress to 12-month development in very preterm infants: Preliminary findings on epigenetic mechanisms and brain growth

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    Very preterm (VPT) infants admitted to Neonatal Intensive Care Unit (NICU) are at risk for altered brain growth and less-than-optimal socio-emotional development. Recent research suggests that early NICU-related stress contributes to socio-emotional impairments in VPT infants at 3 months through epigenetic regulation (i.e., DNA methylation) of the serotonin transporter gene (SLC6A4). In the present longitudinal study we assessed: (a) the effects of NICU-related stress and SLC6A4 methylation variations from birth to discharge on brain development at term equivalent age (TEA); (b) the association between brain volume at TEA and socio-emotional development (i.e., Personal-Social scale of Griffith Mental Development Scales, GMDS) at 12 months corrected age (CA). Twenty-four infants had complete data at 12-month-age. SLC6A4 methylation was measured at a specific CpG previously associated with NICU-related stress and socio-emotional stress. Findings confirmed that higher NICU-related stress associated with greater increase of SLC6A4 methylation at NICU discharge. Moreover, higher SLC6A4 discharge methylation was associated with reduced anterior temporal lobe (ATL) volume at TEA, which in turn was significantly associated with less-than-optimal GMDS Personal-Social scale score at 12 months CA. The reduced ATL volume at TEA mediated the pathway linking stress-related increase in SLC6A4 methylation at NICU discharge and socio-emotional development at 12 months CA. These findings suggest that early adversity-related epigenetic changes might contribute to the long-lasting programming of socio-emotional development in VPT infants through epigenetic regulation and structural modifications of the developing brain

    Alpha Lipoic Acid (ALA) effects on subchorionic hematoma. Preliminary clinical results

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    OBJECTIVE: The clinic use of alpha Lipoic Acid (ALA) is linked to its capability to exert antioxidant effects and, more interestingly, to counteract the pathologic changes of complex networks of cytokines, chemokines and growth factors, restoring their physiological state. The aim of this randomized controlled clinical trial was to test the contribution of oral supplementation of ALA to the standard treatment with Progesterone vaginal suppositories, in healing subchorionic hematomas in patients with threatened miscarriage. Controls were administered only Progesterone suppositories. PATIENTS AND METHODS: Nineteen pregnant women in the first trimester of gestation, with threatened miscarriage and ultrasound evidence of subchorionic hematoma, were included in the trial and randomly divided in two groups: controls, treated with 400 mg Progesterone (200 mg 2 times per day), given by vaginal suppositories, and case study treated with the same Progesterone dosage, plus ALA, given orally at the dose of 600 mg (300 mg 2 times per day, DAVÂź, Lo.Li. Pharma srl, Italy). Sixteen patients completed the trial. Treatment was performed until complete resolution of the clinical picture. RESULTS: In both groups, the subjects improved significantly but, in general, a better and faster evolution in the major signs of threatened miscarriage was observed in the subjects treated with ALA and Progesterone. In these patients, the speed of resorption of subchorionic hematoma was significantly (p ≀ 0.05) superior compared to controls. The ALA and Progesterone group showed a faster decrease or disappearance of all symptoms than that observed in the control group, however the difference was not significant. CONCLUSIONS: These preliminary results suggest that ALA supplementation significantly contributes to speed up the process of restoration of physiological conditions in threatened miscarriage and ameliorates the medical conditions of both the mothers and the foetus, probably modulating the networks of cytokines, growth factors and other molecules
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