1,000 research outputs found

    Agricultural research for nutrition outcomes – rethinking the agenda

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    Agriculture and food are assumed to be critical determinants of stunting and micronutrient deficiency. However, agriculture research for development has not translated as expected into better nutrition outcomes. We argue that to do so, agriculture research needs to be fundamentally changed, from the current emphasis on supply-side production and productivity goals to understanding consumption and addressing factors that can improve diet quality. Some of the research will be to improve the efficiency of supply for more nutritious foods. Other research will need to focus on factors that promote diet quality rather than focus on food security goals through stocks of staple cereals. Because of its importance in low-income, high-burden countries, agriculture can also contribute more effectively to multisectoral nutrition-sensitive development strategies and programs. Critical roles for agricultural research in multisectoral actions will be better metrics, indicators and research studies for diet quality and better evaluation methods – both randomized trials for specific interventions and contribution analysis through theories of change for more complex multisectoral system interventions to prevent stunting and micronutrient deficiencies. To achieve improvements in nutrition outcomes at scale, researchers must engage in new partnerships. In food systems, these partnerships must include more disciplines from agriculture and food science through economics and social science to business and delivery science. Food system researchers will also need to engage more with value chain actors and policy makers. Current efforts to improve nutrition outcomes at scale are severely hampered by data and evidence gaps that prevent better decisions and faster learning

    Quantum interference within the complex quantum Hamilton-Jacobi formalism

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    Quantum interference is investigated within the complex quantum Hamilton-Jacobi formalism. As shown in a previous work [Phys. Rev. Lett. 102, 250401 (2009)], complex quantum trajectories display helical wrapping around stagnation tubes and hyperbolic deflection near vortical tubes, these structures being prominent features of quantum caves in space-time Argand plots. Here, we further analyze the divergence and vorticity of the quantum momentum function along streamlines near poles, showing the intricacy of the complex dynamics. Nevertheless, despite this behavior, we show that the appearance of the well-known interference features (on the real axis) can be easily understood in terms of the rotation of the nodal line in the complex plane. This offers a unified description of interference as well as an elegant and practical method to compute the lifetime for interference features, defined in terms of the average wrapping time, i.e., considering such features as a resonant process.Comment: revised version, 13 pages, 11 figures, 1 tabl

    Low tropical diversity during the adaptive radiation of early land plants.

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    The latitudinal biodiversity gradient, with tropical regions acting as 'evolutionary cradles', is a cornerstone of current biogeographical and ecological theory1. In the modern world floral biodiversity and biomass are overwhelmingly concentrated in the tropics, and it is often assumed that the tropics were evolutionary cradles throughout land plant evolutionary history. For example, the origination and diversification of angiosperms is believed to have taken place in the Cretaceous tropics2 and modern gymnosperms in the Permian tropics3. Here, we show that during the first major diversification of land plants, in the Late Silurian-Early Devonian, land plant biodiversity was much lower at the equator compared to medium-high southern latitudes. Throughout this crucial interval of plant evolution, tropical vegetation remained depauperate and of very low taxonomic biodiversity, although with similar morphological disparity to the more diverse higher latitude floras. Possible explanations for this low tropical floral biodiversity include palaeocontinental configuration or adverse palaeotropical environmental conditions. We discount the possibility that it was simply a fortuitous feature of the biogeographical spread of the earliest vascular land plants.National Geographi

    The effects of terlipressin and direct portacaval shunting on liver hemodynamics following 80% hepatectomy in the pig

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    Liver failure is the major cause of death following liver resection. Post-resection portal venous pressure (PVP) predicts liver failure, is implicated in its pathogenesis, and when PVP is reduced, rates of liver dysfunction decrease. The aim of the present study was to characterize the hemodynamic, biochemical, and histological changes induced by 80% hepatectomy in non-cirrhotic pigs and determine if terlipressin or direct portacaval shunting can modulate these effects. Pigs were randomized (n=8/group) to undergo 80% hepatectomy alone (control); terlipressin (2 mg bolus + 0.5–1 mg/h) + 80% hepatectomy; or portacaval shunt (PCS) + 80% hepatectomy, and were maintained under terminal anesthesia for 8 h. The primary outcome was changed in PVP. Secondary outcomes included portal venous flow (PVF), hepatic arterial flow (HAF), and biochemical and histological markers of liver injury. Hepatectomy increased PVP (9.3 ± 0.4 mmHg pre-hepatectomy compared with 13.0 ± 0.8 mmHg post-hepatectomy, P<0.0001) and PVF/g liver (1.2 ± 0.2 compared with 6.0 ± 0.6 ml/min/g, P<0.0001) and decreased HAF (70.8 ± 5.0 compared with 41.8 ± 5.7 ml/min, P=0.002). Terlipressin and PCS reduced PVP (terlipressin = 10.4 ± 0.8 mmHg, P=0.046 and PCS = 8.3 ± 1.2 mmHg, P=0.025) and PVF (control = 869.0 ± 36.1 ml/min compared with terlipressin = 565.6 ± 25.7 ml/min, P<0.0001 and PCS = 488.4 ± 106.4 ml/min, P=0.002) compared with control. Treatment with terlipressin increased HAF (73.2 ± 11.3 ml/min) compared with control (40.3 ± 6.3 ml/min, P=0.026). The results of the present study suggest that terlipressin and PCS may have a role in the prevention and treatment of post-resection liver failure

    Communication and control system for a 15-channel hermetic retinal prosthesis

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    A small, hermetic, wirelessly-controlled retinal prosthesis has been developed for pre-clinical studies in Yucatan minipigs. The device was attached conformally to the outside of the eye in the socket and received both power and data wirelessly from external sources. Based on the received image data, the prosthesis drove a subretinal thin-film polyimide array of sputtered iridium oxide stimulating electrodes. The implanted device included a hermetic titanium case containing a 15-channel stimulator and receiver chip and discrete circuit components. Feedthroughs in the hermetic case connected the chip to secondary power- and data-receiving coils, which coupled to corresponding external power and data coils driven by power amplifiers. Power was delivered by a 125 kHz carrier, and data were delivered by amplitude shift keying of a 15.5 MHz carrier at 100 kbps. Stimulation pulse strength, duration and frequency were programmed wirelessly from an external computer system. The final assembly was tested in vitro in physiological saline and in vivo in two minipigs for up to five and a half months by measuring stimulus artifacts generated by the implant's current drivers.United States. Dept. of Veteran AffairsUnited states. Dept. of Veterans Affairs. Boston Healthcare SystemNational Institutes of Health (U.S.)United States. Dept. of DefenseMassachusetts Lions Foundatio

    Transiting Disintegrating Planetary Debris around WD 1145+017

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    More than a decade after astronomers realized that disrupted planetary material likely pollutes the surfaces of many white dwarf stars, the discovery of transiting debris orbiting the white dwarf WD 1145+017 has opened the door to new explorations of this process. We describe the observational evidence for transiting planetary material and the current theoretical understanding (and in some cases lack thereof) of the phenomenon.Comment: Invited review chapter. Accepted March 23, 2017 and published October 7, 2017 in the Handbook of Exoplanets. 15 pages, 10 figure

    Existential Communication and Leadership

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    The aim of this article is to introduce and explain a number of important existentialist philosophers and concepts that we believe can contribute to a critical approach to leadership theory. Emphasis is placed on understanding the nature of communication from an existentialist perspective and so Jaspers' conceptualization of existential communication is introduced along with important related concepts that may be regarded as important facets of leader communication including Being-in-the-world, the Other, intersubjectivity, dialogue and indirect communication. Particular attention is paid to Buber's ideas on communication as relationship and dialogue. Throughout, reference is made to contemporary, and what is often regarded as orthodox, thinking regarding the centrality of communication to leadership practice as a means by which to highlight the salience of an existentialist analysis

    Soluble HIV-1 Env trimers in adjuvant elicit potent and diverse functional B cell responses in primates

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    Broadly neutralizing antibodies (bNAbs) against the HIV-1 envelope glycoproteins (Envs) have proven difficult to elicit by immunization. Therefore, to identify effective Env neutralization targets, efforts are underway to define the specificities of bNAbs in chronically infected individuals. For a prophylactic vaccine, it is equally important to define the immunogenic properties of the heavily glycosylated Env in healthy primates devoid of confounding HIV-induced pathogenic factors. We used rhesus macaques to investigate the magnitude and kinetics of B cell responses stimulated by Env trimers in adjuvant. Robust Env-specific memory B cell responses and high titers of circulating antibodies developed after trimer inoculation. Subsequent immunizations resulted in significant expansion of Env-specific IgG-producing plasma cell populations and circulating Abs that displayed increasing avidity and neutralization capacity. The neutralizing activity elicited with the regimen used was, in most aspects, superior to that elicited by a regimen based on monomeric Env immunization in humans. Despite the potency and breadth of the trimer-elicited response, protection against heterologous rectal simian-HIV (SHIV) challenge was modest, illustrating the challenge of eliciting sufficient titers of cross-reactive protective NAbs in mucosal sites. These data provide important information for the design and evaluation of vaccines aimed at stimulating protective HIV-1 immune responses in humans
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