842 research outputs found

    Orienting coupled quantum rotors by ultrashort laser pulses

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    We point out that the non-adiabatic orientation of quantum rotors, produced by ultrashort laser pulses, is remarkably enhanced by introducing dipolar interaction between the rotors. This enhanced orientation of quantum rotors is in contrast with the behavior of classical paired rotors, in which dipolar interactions prevent the orientation of the rotors. We demonstrate also that a specially designed sequence of pulses can most efficiently enhances the orientation of quantum paired rotors.Comment: 7 pages, 5 figures, to appear in Phys. Rev.

    Geometry of General Hypersurfaces in Spacetime: Junction Conditions

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    We study imbedded hypersurfaces in spacetime whose causal character is allowed to change from point to point. Inherited geometrical structures on these hypersurfaces are defined by two methods: first, the standard rigged connection induced by a rigging vector (a vector not tangent to the hypersurface anywhere); and a second, more physically adapted, where each observer in spacetime induces a new type of connection that we call the rigged metric connection. The generalisation of the Gauss and Codazzi equations are also given. With the above machinery, we attack the problem of matching two spacetimes across a general hypersurface. It is seen that the preliminary junction conditions allowing for the correct definition of Einstein's equations in the distributional sense reduce to the requirement that the first fundamental form of the hypersurface be continuous. The Bianchi identities are then proven to hold in the distributional sense. Next, we find the proper junction conditions which forbid the appearance of singular parts in the curvature. Finally, we derive the physical implications of the junction conditions: only six independent discontinuities of the Riemann tensor are allowed. These are six matter discontinuities at non-null points of the hypersurface. For null points, the existence of two arbitrary discontinuities of the Weyl tensor (together with four in the matter tensor) are also allowed.Comment: Latex, no figure

    Driving impact through base of the pyramid distribution models: The role of intermediary organizations

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    Purpose: The purpose of this paper is to answer the following research question: how can intermediaries contribute to social impact creation through their interventions at different levels of distribution networks in the base of the pyramid (BoP) markets? Design/methodology/approach: The paper adopts an embedded case study of an intermediary organization. The analysis focuses on the intervention of the intermediary on the distribution stages of supply chains in four different projects in the food sector in Ethiopia, Benin, Nigeria and Bangladesh. Findings: The embedded case study reveals essential formal and informal roles undertaken by the intermediary organization to develop decentralized distribution networks based on local micro-entrepreneurs. The study proposes that efforts undertaken by the intermediaries toward knowledge sharing and capacity building among partners can enable the adoption of pro-poor strategies across the supply chain. Moreover, hybrid intermediaries can act as “guardians” of the mutual value creation approach since one of their key roles is to advocate the needs of the BoP. Research limitations/implications: Important implications for improving nutrition and food security in the BoP markets are developed based on the empirical findings. The findings open avenues for further research into the antecedents of retention rates in distribution networks based on local micro-entrepreneurs. Practical implications: Findings have implications for different types of BoP initiatives by highlighting how intermediary organizations intervene to develop distribution models with a special focus on social impact. Originality/value: This paper fills an important research gap by discussing social impact aspects in BoP supply chains by adopting the perspective of intermediary organizations

    Phenolic Compounds and Antifungal Activity of Hedera helix L. (Ivy) Flowers and Fruits

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    Identification and quantitative analysis of the phenolic compounds from Hedera helix L. (ivy) flower and fruit ethanol extracts by LC/MS, in vitro germination and growth inhibition effects on Aspergillus niger, Botrytis cinerea, Fusarium oxysporum f.sp. tulipae, Penicillium gladioli and Sclerotinia sclerotiorum were performed. In the non-hydrolyzed samples of flower and fruit extracts were determined, in different amounts, five polyphenols (p-coumaric acid, ferulic acid, rutoside, quercetol and kaempferol) while quercitrin was identified only in the ivy flower extract. The hydrolyzed samples of the same ivy extracts indicated four phenolic compounds (p-coumaric acid, ferulic acid, quercetol and kaempferol), in different concentrations, whereas sinapic acid was only detected in the ivy fruit extract. The antifungal activity of the fresh flower extract was stronger than that of the fresh fruit extract and was compared to that of an antimycotic drug

    Wireless Transmission of Monitoring Data out of an Underground Repository: Results of Field Demonstrations Performed at the HADES Underground Laboratory -13589

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    ABSTRACT As part of the European 7th framework project MoDeRn, Nuclear Research and Consultancy Group (NRG) performed experiments in order to demonstrate the feasibility of wireless data transmission through the subsurface over large distances by low frequency magnetic fields in the framework of the geological disposal of radioactive waste. The main objective of NRG's contribution is to characterize and optimize the energy use of this technique within the specific context of post-closure monitoring of a repository. For that, measurements have been performed in the HADES Underground Research Laboratory (URL) located at Mol, Belgium, at 225 m depth. The experimental set-up utilizes a loop antenna for the transmitter that has been matched to the existing infrastructure of the HADES. Between 2010 and 2012 NRG carried out several experiments at the HADES URL in order to test the technical set-up and to characterize the propagation behavior of the geological medium and the local background noise pattern. Transmission channels have been identified and data transmission has been demonstrated at several frequencies, with data rates up to 10 bit/s and bit error rates <1%. A mathematical model description that includes the most relevant characteristics of the transmitter, transmission path, and receiver has been developed and applied to analyze possible options to optimize the set-up. With respect to the energy-efficiency, results so far have shown that data transmission over larger distances through the subsurface is a feasible option. To support the conclusions on the energy need per bit of transmitted data, additional experiments are foreseen

    Bea score study and correlations with the survival of surgical position conclusions

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    Purpose: To evaluate the applicability of Baseline Event Anticipation score (BEA), as a prognostic factor for complications in cases of cirrhotic patients. Material and Methods: Population chosen for the study was represented by patients suffering from cirrhosis, being evaluated through BEA prognostic score sensibility, using the online formula.(http://hepatitis –delta/org/physicians-and-scientists/calculator). Results: The lot of operated patients where 54, with an average age of 43.4 ± 4.3 years; 53% of them were male and 47% female. All patients had Azygo-Portal Devascularization Hassab-Kaliba, histologically distributed as : micronodular hepatic cirrhosis - 24 (44.4%) macronodular- 16 (29.6%) and micro-macronodular - 14 (25.9%). In the analysis was a prevalence of the BEA-B score - 21 cases (38.9%), followed by 17 cases (31.5%) with BEA-A score and 16 cases (29.6%) with BEA-C score. After surgery 7 patients had 15 complications: early (6) and late (9), surgical (3) and therapeutic (12). Comparing the results, there is a direct correlation, r = 0.233 of the BEA-C score with the incidence of complications, and a decrease in BEA-A and BEA-B patients. Conclusions: This retrospective study was conducted in a specialized center with a reduced sample size, it demonstrates the prognostic utility of the BEA score and apparently requires care that will improve perioperative recovery, and will reduce morbidity

    Synergy between a collagen IV mimetic peptide and a somatotropin-domain derived peptide as angiogenesis and lymphangiogenesis inhibitors

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    Angiogenesis is central to many physiological and pathological processes. Here we show two potent bioinformatically-identified peptides, one derived from collagen IV and translationally optimized, and one from a somatotropin domain-containing protein, synergize in angiogenesis and lymphangiogenesis assays including cell adhesion, migration and in vivo Matrigel plugs. Peptide-peptide combination therapies have recently been applied to diseases such as human immunodeficiency virus (HIV), but remain uncommon thus far in cancer, age-related macular degeneration and other angiogenesis-dependent diseases. Previous work from our group has shown that the collagen IV-derived peptide primarily binds β1 integrins, while the receptor for the somatotropin-derived peptide remains unknown. We investigate these peptides’ mechanisms of action and find both peptides affect the vascular endothelial growth factor (VEGF) pathway as well as focal adhesion kinase (FAK) by changes in phosphorylation level and total protein content. Blocking of FAK both through binding of β1 integrins and through inhibition of VEGFR2 accounts for the synergy we observe. Since resistance through activation of multiple signaling pathways is a central problem of anti-angiogenic therapies in diseases such as cancer, we suggest that peptide combinations such as these are an approach that should be considered as a means to sustain anti-angiogenic and anti-lymphangiogenic therapy and improve efficacy of treatment

    A Multilevel Analysis of Implicit and Explicit CSR in French and UK Professional Sport

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    Research question: This paper examines the ways in which French and UK professional sports clubs implement and communicate their CSR policies. In addition to identifying similarities and differences between CSR practices in the two countries, our analysis extends and adapts the implicit-explicit CSR framework to the field of sport. Research methods: We used a mixed methods approach to analyse qualitative and quantitative data on the CSR strategies of 66 professional rugby union (Top 14, Aviva Premiership Rugby) and football (Ligue 1, Premier League) clubs over the 2017-2018 season. Results and findings: We found major differences in CSR communication between France and the UK. Communication by French clubs tends to highlight sport’s values, involve few media channels, whereas communication by UK clubs explicitly vaunts their social responsibility and involves numerous channels. In the case of CSR implementation, there are similarities between French and UK clubs, especially in the fields their CSR initiatives cover (e.g., health, diversity), as well as differences. However, the scope of initiatives varies more between sports than between countries, with football demonstrating a more international outlook than rugby. Implications: This article expands Matten and Moon’s (2008) implicit-explicit CSR framework by identifying the influence of interactions between sectorial/field-level factors and national/macro-level factors on CSR practices, and by distinguishing between CSR communication and CSR implementation. Our results throw light on the shift from implicit to explicit CSR in French professional sport

    Evaluation of Left Atrial Size and Function: Relevance for Clinical Practice

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    Left atrial (LA) structural and functional evaluation have recently emerged as powerful biomarkers for adverse events in a variety of cardiovascular conditions. Moreover, noninvasive evaluation of LA pressure has gained importance in the characterization of the hemodynamic profile of patients. This review describes the methodology, benefits and pitfalls of measuring LA size and function by echocardiography and provides a brief overview of the prognostic utility of newer echocardiographic metrics of LA geometry and function (i.e., three-dimensional volumes, longitudinal strain, and phasic function parameters)

    Advances in Li-Ion battery management for electric vehicles

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    This paper aims at presenting new solutions for advanced Li-Ion battery management to meet the performance, cost and safety requirements of automotive applications. Emphasis is given to monitoring and controlling the battery temperature, a parameter which dramatically affects the performance, lifetime, and safety of Li-Ion batteries. In addition to this, an innovative battery management architecture is introduced to facilitate the development and integration of advanced battery control algorithms. It exploits the concept of smart cells combined with an FPGA-based centralized unit. The effectiveness of the proposed solutions is shown through hardware-in-the-loop simulations and experimental results
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