313 research outputs found

    Signatures of exciton coupling in paired nanoemitters

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    An exciton formed by the delocalized electronic excitation of paired nanoemitters is interpreted in terms of the electromagnetic emission of the pair and their mutual coupling with a photodetector. A formulation directly tailored for fluorescence detection is identified, giving results which are strongly dependent on geometry and selection rules. Signature symmetric and antisymmetric combinations are analyzed and their distinctive features identified

    Climate and southern Africa's water-energy-food nexus

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    In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and Gross Domestic Product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose; the Southern African Development Community, the Southern African Power Pool, and trade of agricultural products amounting to significant transfers of embedded water

    Silicon Mie Resonators for Highly Directional Light Emission from monolayer MoS2

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    Controlling light emission from quantum emitters has important applications ranging from solid-state lighting and displays to nanoscale single-photon sources. Optical antennas have emerged as promising tools to achieve such control right at the location of the emitter, without the need for bulky, external optics. Semiconductor nanoantennas are particularly practical for this purpose because simple geometries, such as wires and spheres, support multiple, degenerate optical resonances. Here, we start by modifying Mie scattering theory developed for plane wave illumination to describe scattering of dipole emission. We then use this theory and experiments to demonstrate several pathways to achieve control over the directionality, polarization state, and spectral emission that rely on a coherent coupling of an emitting dipole to optical resonances of a Si nanowire. A forward-to-backward ratio of 20 was demonstrated for the electric dipole emission at 680 nm from a monolayer MoS2 by optically coupling it to a Si nanowire

    Market analysis for cultured proteins in low- and lower-middle income countries.

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    The global burden of malnutrition is unacceptably high.10 Worldwide, an estimated 22% of children under the age of five were stunted and 8% were wasted in 2018.11 Low-quality diets lacking in essential vitamins, minerals, proteins, and other nutrients are a key contributor to this burden.12 Animal-source foods—such as meat, poultry, fish, eggs, and dairy—are important components of a diverse diet and provide high-quality proteins and other essential nutrients that promote optimal growth and development.13,14,15,16,17As populations and incomes grow, the global demand for animal-source foods is projected to increase substantially, particularly in many low- and lower-middle income countries (LMICs).18,19 However, cost is currently a significant barrier to animal-source food consumption. In addition, meeting this growing demand for animal-source foods will require rapid increases in livestock production, which has significant environmental impacts, requiring considerable land, water, chemical, and energy inputs.10,17,18 Global food production is responsible for roughly one-quarter of all greenhouse gas emissions, most of which (up to 80%) are related to livestock.20,21 Livestock production is also a contributor to water pollution, deforestation, land degradation, overfishing, and antimicrobial resistance.20,22,23 Given these challenges, this report aims to assess the market for potentially more sustainable alternative proteins and their potential for use in LMIC settings. The report focuses on proteins derived from fermentation-based cellular agriculture, called cultured proteins, given their potential near-term time to market and their potential impact in LMIC populations. Most cultured protein manufacturers are developing proteins that are present in animal-source milk and eggs

    Efficient land water management practice and cropping system for increasing water and crop productivity in semi‐arid tropics

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    In Indian semi-arid tropics (SATs), low water and crop productivity in Vertisols and associated soils are mainly due to poor land management and erratic and low rainfall occurrence. This study was conducted from 2014 to 2016 at the ICRISAT in India to test the effect of broad bed furrows (BBF) as land water management against conventional flatbed planting for improving soil water content (SWC) and water and crop productivity of three cropping systems: sorghum [Sorghum bicolor (L.) Moench]–chickpea (Cicer arientinum L.) and maize (Zea mays)–groundnut (Arachis hypogaea L.) as sequential and pearl millet [Pennisetum glaucum (L.)] + pigeonpea [Cajanus cajan (L.) Millsp.] as intercropping, grown under different nutrients management involving macronutrients (N, P, and K) only and combined application of macro- and micronutrients. The results stated that the SWC in BBF was higher over flatbed by 9.35–10.44% in 0- to 0.3-m, 4.56–9.30% in 0.3- to 0.6-m and 3.85–5.26% in 0.6- to 1.05-m soil depths during the cropping season. Moreover, depletion of the soil water through plant uptake was higher in BBF than in flatbed. Among the cropping systems, sorghum–chickpea was the best in bringing highest system equivalent yield and water productivity with the combined application of macro- and micronutrients. The BBF minimized water stress at critical crop growth stages leading to increase crop yield and water productivity in SATs. Thus, BBF along with the application of macro- and micronutrients could be an adaptation strategy to mitigate erratic rainfall due to climate change in SATs

    Challenges and Prospects in Ocean Circulation Models

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    We revisit the challenges and prospects for ocean circulation models following Griffies et al. (2010). Over the past decade, ocean circulation models evolved through improved understanding, numerics, spatial discretization, grid configurations, parameterizations, data assimilation, environmental monitoring, and process-level observations and modeling. Important large scale applications over the last decade are simulations of the Southern Ocean, the Meridional Overturning Circulation and its variability, and regional sea level change. Submesoscale variability is now routinely resolved in process models and permitted in a few global models, and submesoscale effects are parameterized in most global models. The scales where nonhydrostatic effects become important are beginning to be resolved in regional and process models. Coupling to sea ice, ice shelves, and high-resolution atmospheric models has stimulated new ideas and driven improvements in numerics. Observations have provided insight into turbulence and mixing around the globe and its consequences are assessed through perturbed physics models. Relatedly, parameterizations of the mixing and overturning processes in boundary layers and the ocean interior have improved. New diagnostics being used for evaluating models alongside present and novel observations are briefly referenced. The overall goal is summarizing new developments in ocean modeling, including: how new and existing observations can be used, what modeling challenges remain, and how simulations can be used to support observations.Peer reviewe

    Bifidobacterium longum CECT 7347 Modulates Immune Responses in a Gliadin-Induced Enteropathy Animal Model

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    Coeliac disease (CD) is an autoimmune disorder triggered by gluten proteins (gliadin) that involves innate and adaptive immunity. In this study, we hypothesise that the administration of Bifidobacterium longum CECT 7347, previously selected for reducing gliadin immunotoxic effects in vitro, could exert protective effects in an animal model of gliadin-induced enteropathy. The effects of this bacterium were evaluated in newborn rats fed gliadin alone or sensitised with interferon (IFN)-γ and fed gliadin. Jejunal tissue sections were collected for histological, NFκB mRNA expression and cytokine production analyses. Leukocyte populations and T-cell subsets were analysed in peripheral blood samples. The possible translocation of the bacterium to different organs was determined by plate counting and the composition of the colonic microbiota was quantified by real-time PCR. Feeding gliadin alone reduced enterocyte height and peripheral CD4+ cells, but increased CD4+/Foxp3+ T and CD8+ cells, while the simultaneous administration of B. longum CECT 7347 exerted opposite effects. Animals sensitised with IFN-γ and fed gliadin showed high cellular infiltration, reduced villi width and enterocyte height. Sensitised animals also exhibited increased NFκB mRNA expression and TNF-α production in tissue sections. B. longum CECT 7347 administration increased NFκB expression and IL-10, but reduced TNF-α, production in the enteropathy model. In sensitised gliadin-fed animals, CD4+, CD4+/Foxp3+ and CD8+ T cells increased, whereas the administration of B. longum CECT 7347 reduced CD4+ and CD4+/Foxp3+ cell populations and increased CD8+ T cell populations. The bifidobacterial strain administered represented between 75–95% of the total bifidobacteria isolated from all treated groups, and translocation to organs was not detected. These findings indicate that B. longum attenuates the production of inflammatory cytokines and the CD4+ T-cell mediated immune response in an animal model of gliadin-induced enteropathy

    Mapping Brain Response to Pain in Fibromyalgia Patients Using Temporal Analysis of fMRI

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    Background: Nociceptive stimuli may evoke brain responses longer than the stimulus duration often partially detected by conventional neuroimaging. Fibromyalgia patients typically complain of severe pain from gentle stimuli. We aimed to characterize brain response to painful pressure in fibromyalgia patients by generating activation maps adjusted for the duration of brain responses. Methodology/Principal Findings: Twenty-seven women (mean age: 47.8 years) were assessed with fMRI. The sample included nine fibromyalgia patients and nine healthy subjects who received 4 kg/cm2 of pressure on the thumb. Nine additional control subjects received 6.8 kg/cm2 to match the patients for the severity of perceived pain. Independent Component Analysis characterized the temporal dynamics of the actual brain response to pressure. Statistical parametric maps were estimated using the obtained time courses. Brain response to pressure (18 seconds) consistently exceeded the stimulus application (9 seconds) in somatosensory regions in all groups. fMRI maps following such temporal dynamics showed a complete pain network response (sensory-motor cortices, operculo-insula, cingulate cortex, and basal ganglia) to 4 kg/cm2 of pressure in fibromyalgia patients. In healthy subjects, response to this low intensity pressure involved mainly somatosensory cortices. When matched for perceived pain (6.8 kg/cm2), control subjects showed also comprehensive activation of pain-related regions, but fibromyalgia patients showed significantly larger activation in the anterior insula-basal ganglia complex and the cingulate cortex. Conclusions/Significance: The results suggest that data-driven fMRI assessments may complement conventional neuroimaging for characterizing pain responses and that enhancement of brain activation in fibromyalgia patients may be particularly relevant in emotion-related regions

    Minocycline Inhibition of Monocyte Activation Correlates with Neuronal Protection in SIV NeuroAIDS

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    Background: Minocycline is a tetracycline antibiotic that has been proposed as a potential conjunctive therapy for HIV-1 associated cognitive disorders. Precise mechanism(s) of minocycline’s functions are not well defined. Methods: Fourteen rhesus macaques were SIV infected and neuronal metabolites measured by proton magnetic resonance spectroscopy (1H MRS). Seven received minocycline (4 mg/kg) daily starting at day 28 post-infection (pi). Monocyte expansion and activation were assessed by flow cytometry, cell traffic to lymph nodes, CD16 regulation, viral replication, and cytokine production were studied. Results: Minocycline treatment decreased plasma virus and pro-inflammatory CD14+CD16+ and CD14loCD16+ monocytes, and reduced their expression of CD11b, CD163, CD64, CCR2 and HLA-DR. There was reduced recruitment of monocyte/ macrophages and productively infected cells in axillary lymph nodes. There was an inverse correlation between brain NAA/ Cr (neuronal injury) and circulating CD14+CD16+ and CD14loCD16+ monocytes. Minocycline treatment in vitro reduced SIV replication CD16 expression on activated CD14+CD16+ monocytes, and IL-6 production by monocytes following LPS stimulation. Conclusion: Neuroprotective effects of minocycline are due in part to reduction of activated monocytes, monocyte traffic. Mechanisms for these effects include CD16 regulation, reduced viral replication, and inhibited immune activation. Citation: Campbell JH, Burdo TH, Autissier P, Bombardier JP, Westmoreland SV, et al. (2011) Minocycline Inhibition of Monocyte Activation Correlate
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