2,012 research outputs found

    Logistics service providers and corporate social responsibility: sustainability reporting in the logistics industry

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    Purpose – The purpose of this paper is to present a content analysis of corporate social responsibility (CSR) reports published by logistics service providers (LSPs), and to analyse factors influencing the level and scope of reporting. In order to address this objective, the authors show to what extent various social and environmental categories are covered in the CSR reports. The authors also investigate whether any differences in the use of CSR indicators can be found with regard to the use of a formal reporting framework, the size of a company, location of its headquarter, and ownership structure. Design/methodology/approach – The study begins with a comprehensive literature review on the CSR policies and practices in relation to the field of logistics. A database of 350 international LSPs is compiled based on independent rankings of top logistics companies. Applying a content analysis approach, corporate web sites and CSR reports are examined in order to investigate how sustainability is reported and what CSR-related indicators are published. Statistical analysis is carried out to provide insight into whether any differences in the use of CSR indicators can be found with regard to four key factors identified in the literature review. Findings – Although aspects of sustainability are mentioned on corporate web sites of most LSPs in the database (53 per cent), only 13 per cent publish formal CSR reports. This research identifies a variety of indicators used by LSPs and shows that the use of a formal reporting framework and the size of a company are the two main factors influencing the levels of CSR reporting in the sector. Practical implications – This paper provides an insight into how transparently LSPs report on the sustainability of their performance. LSPs can compare their own CSR reporting approaches to the body of scientific literature and the findings presented in this paper, in order to adapt more general concepts and best practice evidence to their needs. Social implications – By focusing on best practice in reporting of the environmental and social performance, this research can potentially improve the long-term sustainability of the logistics sector. Originality/value – This is the first study providing a comprehensive review of the CSR reporting practice in the third party logistics sector. As such, this paper provides an important basis for CSR-related research in the field of logistics and supply chain management. Several areas for future research are also identified

    Test program to demonstrate the stability of hydrazine in propellant tanks

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    A 24-month coupon test program to evaluate the decomposition of propellant tanks is reported. The propellant fuel evaluated was monopropellant-grade hydrazine (N2H4), which is normally a colorless, fuming, corrosive, strongly reducing liquid. The degree of hydrazine decomposition was determined by means of chemical analyses of the liquid and evolved gases at the end of the test program. The experimental rates of hydrazine decomposition were determined to be within acceptable limits. The propellant tank materials and material combinations were not degraded by a 2-year exposure to hydrazine propellant. This was verified using change-of-weight determinations and microscopic examination of the specimen surface before and after exposure, and by posttest chemical analyses of hydrazine liquid for residual metal content

    Doppler-Free Spectroscopy of Weak Transitions: An Analytical Model Applied to Formaldehyde

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    Experimental observation of Doppler-free signals for weak transitions can be greatly facilitated by an estimate for their expected amplitudes. We derive an analytical model which allows the Doppler-free amplitude to be estimated for small Doppler-free signals. Application of this model to formaldehyde allows the amplitude of experimentally observed Doppler-free signals to be reproduced to within the experimental error.Comment: 7 pages, 7 figures, 1 table, v2: many small improvements + corrected line assignmen

    Experimental Characterization and Modelling of Energy Efficient Fluid Supply Systems

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    In applications such as in agriculture, construction, and aerospace applications, high pressure hydraulics is the preferred technology to transmit mechanical power. As a consequence, the energy efficiency of the hydraulic system used to perform the mechanical actuations is of primary concern to reduce the energy consumptions in the abovementioned applications. In an hydraulic system, the primary component determining the energy efficiency is the hydraulic pump. This work focuses on the study of a particular pump design, also referred as external gear pump, particularly used in applications in which the cost of the hydraulic system has to be minimized. The large use of this type of pump calls for research towards more efficient designs solutions. In particular, new designs for external gear pumps have been developed by Dr. Andrea Vacca’s research group at Purdue using a detailed pump model. This study is intended to gain detailed understanding about the fluid dynamic part of this model by performing detailed comparisons between the simulation results obtained by a different simulation tool, based on a computational fluid dynamics (CFD) approach to simulate the entire pump operation (including the primary displacing action and the internal leakages). After the comparison is made for a commercial geometry, the study will focus on a innovative prototype design, developed to reduce the noise generation while increasing energy efficiency. The results from the CFD approach were validated against the experimentally-backed lumped parameter approach result. The differences between the modeling methods produced differences in the results which were analyzed for both the unit efficiency and flow ripple production

    An Exact Algorithm for TSP in Degree-3 Graphs via Circuit Procedure and Amortization on Connectivity Structure

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    The paper presents an O^*(1.2312^n)-time and polynomial-space algorithm for the traveling salesman problem in an n-vertex graph with maximum degree 3. This improves the previous time bounds of O^*(1.251^n) by Iwama and Nakashima and O^*(1.260^n) by Eppstein. Our algorithm is a simple branch-and-search algorithm. The only branch rule is designed on a cut-circuit structure of a graph induced by unprocessed edges. To improve a time bound by a simple analysis on measure and conquer, we introduce an amortization scheme over the cut-circuit structure by defining the measure of an instance to be the sum of not only weights of vertices but also weights of connected components of the induced graph.Comment: 24 pages and 4 figure

    Identification of transcriptional and metabolic programs related to mammalian cell size

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    SummaryBackgroundRegulation of cell size requires coordination of growth and proliferation. Conditional loss of cyclin-dependent kinase 1 in mice permits hepatocyte growth without cell division, allowing us to study cell size in vivo using transcriptomics and metabolomics.ResultsLarger cells displayed increased expression of cytoskeletal genes but unexpectedly repressed expression of many genes involved in mitochondrial functions. This effect appears to be cell autonomous because cultured Drosophila cells induced to increase cell size displayed a similar gene-expression pattern. Larger hepatocytes also displayed a reduction in the expression of lipogenic transcription factors, especially sterol-regulatory element binding proteins. Inhibition of mitochondrial functions and lipid biosynthesis, which is dependent on mitochondrial metabolism, increased the cell size with reciprocal effects on cell proliferation in several cell lines.ConclusionsWe uncover that large cell-size increase is accompanied by downregulation of mitochondrial gene expression, similar to that observed in diabetic individuals. Mitochondrial metabolism and lipid synthesis are used to couple cell size and cell proliferation. This regulatory mechanism may provide a possible mechanism for sensing metazoan cell size

    Analyzing false memories in children with associative lists specific for their age

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    Two experiments attempted to resolve previous contradictory findings concerning developmental trends in false memories within the Deese-Roediger-McDermott (DRM) paradigm by using an improved methodology-constructing age-appropriate associative lists. The research also extended the DRM paradigm to preschoolers. Experiment 1 (N = 320) included children in three age groups (preschoolers of 3-4 years, second-graders of 7-8 years, and preadolescents of 11-12 years) and adults, and Experiment 2 (N = 64) examined preschoolers and preadolescents. Age-appropriate lists increased false recall. Although preschoolers had fewer false memories than the other age groups, they showed considerable levels of false recall when tested with age-appropriate materials. Results were discussed in terms of fuzzy-trace, source-monitoring, and activation frameworks

    The effects of a plant proteinase inhibitor from Enterolobium contortisiliquum on human tumor cell lines

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    Supplementary to the efficient inhibition of trypsin, chymotrypsin, plasma kallikrein, and plasmin already described by the EcTI inhibitor from Enterolobium contortisiliquum, it also blocks human neutrophil elastase (K(iapp)=4.3 nM) and prevents phorbol ester (PMA)-stimulated activation of matrix metalloproteinase (MMP)-2 probably via interference with membrane-type 1 (MT1)-MMP. Moreover, plasminogen-induced activation of proMMP-9 and processing of active MMP-2 was also inhibited. Furthermore, the effect of EcTI on the human cancer cell lines HCT116 and HT29 (colorectal), SkBr-3 and MCF-7 (breast), K562 and THP-1 (leukemia), as well as on human primary fibroblasts and human mesenchymal stem cells (hMSCs) was studied. EcTI inhibited in a concentration range of 1.0-2.5 mu M rather specifically tumor cell viability without targeting primary fibroblasts and hMSCs. Taken together, our data indicate that the polyspecific proteinase inhibitor EcTI prevents proMMP activation and is cytotoxic against tumor cells without affecting normal tissue remodeling fibroblasts or regenerative hMSCs being an important tool in the studies of tumor cell development and dissemination

    Advances towards understanding the mechanism of action of the Hsp90 Complex

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    Hsp90 (Heat Shock Protein 90) is an ATP (Adenosine triphosphate) molecular chaperone responsible for the activation and maturation of client proteins. The mechanism by which Hsp90 achieves such activation, involving structurally diverse client proteins, has remained enigmatic. However, recent advances using structural techniques, together with advances in biochemical studies, have not only defined the chaperone cycle but have shed light on its mechanism of action. Hsp90 hydrolysis of ATP by each protomer may not be simultaneous and may be dependent on the specific client protein and co-chaperone complex involved. Surprisingly, Hsp90 appears to remodel client proteins, acting as a means by which the structure of the client protein is modified to allow its subsequent refolding to an active state, in the case of kinases, or by making the client protein competent for hormone binding, as in the case of the GR (glucocorticoid receptor). This review looks at selected examples of client proteins, such as CDK4 (cyclin-dependent kinase 4) and GR, which are activated according to the so-called ‘remodelling hypothesis’ for their activation. A detailed description of these activation mechanisms is paramount to understanding how Hsp90-associated diseases develop

    A review on coordination properties of thiol-containing chelating agents towards mercury, cadmium, and lead

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    The present article reviews the clinical use of thiol-based metal chelators in intoxications and overexposure with mercury (Hg), cadmium (Cd), and lead (Pb). Currently, very few commercially available pharmaceuticals can successfully reduce or prevent the toxicity of these metals. The metal chelator meso-2,3-dimercaptosuccinic acid (DMSA) is considerably less toxic than the classical agent British anti-Lewisite (BAL, 2,3-dimercaptopropanol) and is the recommended agent in poisonings with Pb and organic Hg. Its toxicity is also lower than that of DMPS (dimercaptopropane sulfonate), although DMPS is the recommended agent in acute poisonings with Hg salts. It is suggested that intracellular Cd deposits and cerebral deposits of inorganic Hg, to some extent, can be mobilized by a combination of antidotes, but clinical experience with such combinations are lacking. Alpha-lipoic acid (alpha-LA) has been suggested for toxic metal detoxification but is not considered a drug of choice in clinical practice. The molecular mechanisms and chemical equilibria of complex formation of the chelators with the metal ions Hg2+, Cd2+, and Pb2+ are reviewed since insight into these reactions can provide a basis for further development of therapeutics
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