4,306 research outputs found

    Thin-layer chromatography of pigments from reaction center particles of Rhodopseudomonas spheroides

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    1. Pigments extracted from reaction center particles of Rhodopseudomonas spheroides were separated and identified by means of thin-layer chromatography.\ud \ud 2. The results strongly suggest that bacteriochlorophyll a is the only bacteriochlorophyll pigment present in reaction centers.\ud \ud 3. Other compounds identified are bacteriopheophytin a, ubiquinone-10 and spheroidene

    LEGITIMATE VIOLENCE IN ILLEGITIMATE TIMES: DIO’S THEORIES OF LEGITIMACY

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    Comparing legitimacy in the three different contexts of literaryleisteia, Late Republican civil war actors, and contemporary Severanemperors reveals Dio to be consistent when discussing legitimateviolence. In all three, Dio presents establishing legitimacy as aprimary factor in attaining power. As the required skills to achievepower differed from those for ruling, the resulting ruler could bedisastrous. Through employing the ‘noble bandit’ topos, Dioquestions the emperors’ suitability, comparing them to bandits.Overall, Dio interprets Late Republican history differently from hissources for Republican history. In his view, future statesmen cannotrely upon the mos maiorum

    Partial nonlinear reciprocity breaking through ultrafast dynamics in a random photonic medium

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    We demonstrate that ultrafast nonlinear dynamics gives rise to reciprocity breaking in a random photonic medium. Reciprocity breaking is observed via the suppression of coherent backscattering, a manifestation of weak localization of light. The effect is observed in a pump-probe configuration where the pump induces an ultrafast step-change of the refractive index during the dwell time of the probe light in the material. The dynamical suppression of coherent backscattering is reproduced well by a multiple scattering Monte Carlo simulation. Ultrafast reciprocity breaking provides a distinct mechanism in nonlinear optical media which opens up avenues for the active manipulation of mesoscopic transport, random lasers, and photon localization.Comment: 5 pages, 4 figure

    Chronic Obstructive Pulmonary Disease: Emphysema Revisited

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    Throughput of ADSL modems

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    This paper considers the throughput of ADSL (Asymmetric Digital Subscriber Line) modems, used for high-speed data transmission over relatively unreliable connections, e.g. copper telephone wires. The modem technique uses an error correcting code and interleaving. The settings include a grouping factor SS which affects the amount of data per code word, the number RR of redundant bytes per code word and the interleave depth DD. The influence of these parameters on both the effective data transmission rate and the resulting error rate in the received signal are determined for two error situations: random errors and bursts of errors. An approximate analysis for the random error case of the throughput of a TCP (Transport Control Protocol) connection using an ADSL modem shows that maximum throughput is obtained for the highest values of SS and RR

    Giant coronary aneurysms: three-dimensional reconstruction

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    A 31 year old man was referred for the evaluation of chest pain. Cardiac CT reconstruction revealed multiple calcified giant coronary aneurysms. Most likely this patient suffered from subclinical Kawasaki’s disease in his childhood

    Modelling survival and connectivity of Mnemiopsis leidyi in the south-western North Sea and Scheldt estuaries

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    Three different models were applied to study the reproduction, survival and dispersal of Mnemiopsis leidyi in the Scheldt estuaries and the southern North Sea: a high-resolution particle tracking model with passive particles, a low-resolution particle tracking model with a reproduction model coupled to a biogeochemical model, and a dynamic energy budget (DEB) model. The results of the models, each with its strengths and weaknesses, suggest the following conceptual situation: (i) the estuaries possess enough retention capability to keep an overwintering population, and enough exchange with coastal waters of the North Sea to seed offshore populations; (ii) M. leidyi can survive in the North Sea, and be transported over considerable distances, thus facilitating connectivity between coastal embayments; (iii) under current climatic conditions, M. leidyi may not be able to reproduce in large numbers in coastal and offshore waters of the North Sea, but this may change with global warming; however, this result is subject to substantial uncertainty. Further quantitative observational work is needed on the effects of temperature, salinity and food availability on reproduction and on mortality at different life stages to improve models such as used here

    A Formal Framework for Modeling Trust and Reputation in Collective Adaptive Systems

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    Trust and reputation models for distributed, collaborative systems have been studied and applied in several domains, in order to stimulate cooperation while preventing selfish and malicious behaviors. Nonetheless, such models have received less attention in the process of specifying and analyzing formally the functionalities of the systems mentioned above. The objective of this paper is to define a process algebraic framework for the modeling of systems that use (i) trust and reputation to govern the interactions among nodes, and (ii) communication models characterized by a high level of adaptiveness and flexibility. Hence, we propose a formalism for verifying, through model checking techniques, the robustness of these systems with respect to the typical attacks conducted against webs of trust.Comment: In Proceedings FORECAST 2016, arXiv:1607.0200

    Developing capacities of community health workers in sexual and reproductive, maternal, newborn, child, and adolescent health: A mapping and review of training resources

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    Background: Given country demands for support in the training of community health workers (CHWs) to accelerate progress towards reaching the Millennium Development Goals in sexual and reproductive health and maternal, newborn, child, and adolescent health (SR/MNCAH), the United Nations Health Agencies conducted a synthesis of existing training resource packages for CHWs in different components of SR/MNCAH to identify gaps and opportunities and inform efforts to harmonize approaches to developing the capacity of CHWs. Methods: A mapping of training resource packages for CHWs was undertaken with documents retrieved online and from key informants. Materials were classified by health themes and analysed using agreed parameters. Ways forward were informed by a subsequent expert consultation. Results: We identified 31 relevant packages. They covered different components of the SR/MNCAH continuum in varying breadth (integrated packages) and depth (focused packages), including family planning, antenatal and childbirth care (mainly postpartum haemorrhage), newborn care, and childhood care, and HIV. There is no or limited coverage of interventions related to safe abortion, adolescent health, and gender-based violence. There is no training package addressing the range of evidence-based interventions that can be delivered by CHWs as per World Health Organization guidance. Gaps include weakness in the assessment of competencies of trainees, in supportive supervision, and in impact assessment of packages. Many packages represent individual programme efforts rather than national programme materials, which could reflect weak integration into national health systems. Conclusions: There is a wealth of training packages on SR/MNCAH for CHWs which reflects interest in strengthening the capacity of CHWs. This offers an opportunity for governments and partners to mount a synergistic response to address the gaps and ensure an evidence-based comprehensive package of interventions to be delivered by CHWs. Packages with defined competencies and methods for assessing competencies and supervision are considered best practices but remain a gap. © 2014 Tran et al
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