1,375 research outputs found

    Low-pressure Chemical Vapour Deposition of Silicon Nanoparticles:Synthesis and Characterisation

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    emiconductor nanostructures such as quantum wells, quantum wires or quantum dots exhibit superior properties in comparison to their bulk forms. Quantum dots are described aszero-dimensional electron gas system, as carriers are confined in all the three directions. Densityof states is discrete function of energy. Allowed energy spectrum is discrete like in an atom.Energy band gap is broadened due to carriers confinement. Semiconductor quantum dots exhibittypical coulomb blockade characteristic which is exploited for development of new generationof nanoelectronic devices namely single-electron transistor, memories, etc, whose operationdepends on quantum mechanical tunneling of carriers through energy barriers. Thesesemiconductor nanostructures emit light in visible range upon excitation by optical means. Inrecent years,  research  has been focused on different nano-scale materials; metals (Au, Ag, Fe,Mn, Ni), metal oxides (SnO2, ZnO2), compound semiconductors (GaAs, GaAlAs, CdSe, CdS,GaN), and elemental semiconductors (silicon and germanium). As silicon is the most favouredmaterial in the established integrated circuits manufacturing technology, research is being donefor controlled synthesis and characterisation of Si nanoparticles. The Si nanoparticles havebeen synthesised on oxide and nitride layers over  Si substrate by IC technology compatiblelow-pressure chemical vapour deposition technique. Atomic force microscopy (AFM)characterisation has been extensively carried out on the samples. It is shown that the tip radiusand shape of tip lead to less accurate estimate of the actual size. The AFM images have been evaluated based on the real surface topography and shape of the tip. Photolumine scence (PL) studies have been performed to characterise the samples. The PL measurements showed visiblelight emission from synthesised silicon nanoparticles.Defence Science Journal, 2008, 58(4), pp.550-558, DOI:http://dx.doi.org/10.14429/dsj.58.167

    Enhancing Resource Use Efficiency Through Soil Management for Improving Livelihoods

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    Sustainable intensification and improvement in farm-based livelihoods particularly in dryland tropics are the biggest challenges of the century. Widespread soil degradation, growing water scarcity, and looming threat of climate change further compound the problem of achieving food and nutritional security along with improved livelihoods. Large yield gaps in drylands provide a huge opportunity to increase the food production for future food security and mainstreaming of drylands. Soil management for correcting micro and secondary nutrient deficiencies has shown to increase crop productivity by 20–66% in Karnataka, India. During 2009–2013 in this state, more than 5 million farmers benefitted and net economic benefits through increased production were estimated to the tune of US$353 million (Rs. 1963 crores). Balanced nutrition led to increased nitrogen uptake efficiency, utilization efficiency, and use efficiency for grain yield and harvest index. Best practices like soil test-based fertilization including micronutrients and improved cultivars also contribute to increasing rainwater use efficiency in crops by channelizing unproductive evaporation loss into productive transpiration. In current rainy fallow regions, the landform management like broadbed and furrow along with balanced nutrition has shown that fallow lands in black soil regions in Madhya Pradesh can be successfully cultivated to grow soybean crop. Similarly soil fertility management along with other best practices provides opportunities for intensification through cultivating 11.4 million ha rice fallow in India by growing of early maturing chickpea. Thus, efficient rainy and post-rice fallow management is a way forward to enhance land use efficiency for higher productivity and incomes. Along with productivity and economic benefits, improved soil-nutrient-crop-water management is found to contribute to organic C building, enhancing microbial activity and resilience building of production systems. Efficient soil management thus serves as a foundation to enhance livelihoods through resource-efficient production and providing opportunities for scaling up

    Interaction of annexin A6 with alpha actinin in cardiomyocytes

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    <p>Abstract</p> <p>Background</p> <p>Annexins are calcium dependent phospholipid binding proteins that are expressed in a wide variety of tissues and implicated in various extra- and intracellular processes. In myocardial tissue, annexins A2, A5 and A6 are particularly abundant, of which the expression levels of annexin A6 has been found to be maximal. Conflicting reports from transgenic mice overexpressing annexin A6 or null mice lacking annexin A6 showed imbalances in intracellular calcium turnover and disturbed cardiac contractility. However, few studies have focussed on the signalling module of annexin A6 in the heart either in normal or in pathological state.</p> <p>Results</p> <p>To identify the putative binding partners of annexin A6 in the heart, ventricular extracts were subjected to glutathione S-transferase (GST)- annexin A6 pull down assay and the GST- annexin A6 bound proteins were identified by mass spectrometry. The pull down fractions of ventricular extracts with GST-full length annexin A6 as well as GST-C terminus deleted annexin A6 when immunoblotted with anti sarcomeric alpha (α)-actinin antibody showed the presence of α-actinin in the immunoblot which was absent when GST-N terminus deleted annexin A6 was used for pull down. Overexpression of green fluorescent protein (GFP) tagged full length annexin A6 showed z-line like appearance in cardiomyocytes whereas GFP-N termimus deleted annexin A6 was mostly localized to the nucleus. Overexpression of GFP-C terminus deleted annexin A6 in cardiomyocytes showed aggregate like appearance in the cytoplasm. Double immunofluorescent staining of cardiomyocytes with anti annexin A6 and anti sarcomeric α-actinin antibodies showed perfect co-localization of these two proteins with annexin A6 appearing like a component of sarcomere. Transient knockdown of annexin A6 in cardiomyocytes by shRNA significantly enhances the contractile functions but does not affect the z-band architecture, as revealed by α-actinin immunostaining in shRNA treated cells.</p> <p>Conclusions</p> <p>In overall, the present study demonstrated for the first time that annexin A6 physically interacts with sarcomeric α-actinin and alters contractility of cardiomyocytes suggesting that it might play important role in excitation and contraction process.</p

    Equity as a Prerequisite for Stability of Cooperation on Global Public Good Provision

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    Analysing cooperative provision of a global public good such as climate protection, we explore the relationship between equitable burden sharing on the one hand and core stability on the other. To assess the size of the burden which a public good contribution entails for a country, we make use of a specific measure based on Moulin (Econometrica 55:963-977, 1987). In particular, we show that a Pareto optimal allocation which is not in the core can always be blocked by a group of countries with the highest Moulin sacrifices. In this sense, it is the 'overburdening' and thus 'unfair' treatment of some countries that provides the reason for core instability. By contrast, a Pareto optimal allocation is in the core if the public good contributions are fairly equally distributed according to their Moulin sacrifices. The potential implications of our theoretical analysis for global climate policy are also discussed

    The influence of rs53576 polymorphism in the oxytocin receptor (OXTR) gene on empathy in healthy adults by subtype and ethnicity: a systematic review and meta-analysis

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    Empathy is essential for navigating complex social environments. Prior work has shown associations between rs53576, a single nucleotide polymorphism (SNP) located in the oxytocin receptor gene (OXTR), and generalized empathy. We undertook a systematic review and meta-analysis to assess the effects of rs53576 on subdomains of empathy, specifically cognitive empathy (CE) and affective empathy (AE), in healthy adults. Twenty cohorts of 8933 participants aged 18-98 were identified, including data from the Sydney Memory and Ageing Study, a cohort of older community adults. Meta-analyses found G homozygotes had greater generalized empathic abilities only in young to middle-aged adults. While meta-analyses of empathy subdomains yielded no significant overall effects, there were differential effects based on ethnicity. G homozygotes were associated with greater CE abilities in Asian cohorts (standardized mean difference; SMD: 0.09 [2.8·10-3-0.18]), and greater AE performance in European cohorts [SMD: 0.12 (0.04-0.21)]. The current literature highlights a need for further work that distinguishes between genetic and ethnocultural effects and explores effects of advanced age on this relationship

    Controlling molecular conformation for highly efficient and stable deep-blue copolymer light-emitting diodes

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    We report a novel approach to the achievement of deep-blue, high-efficiency, and long-lived solution processed polymer light-emitting diodes (PLEDs) via a simple molecular-level conformation change whereby we introduce rigid β-phase segments into a 95% fluorene - 5% arylamine copolymer emission layer (EML). The arylamine moieties at low density act as efficient exciton formation sites in PLEDs whilst the conformational change alters the nature of the dominant luminescence from a broad, charge-transfer like emission to a significantly blue-shifted and highly vibronically structured, excitonic emission. As a consequence, we observe a significant improvement in Commission International de L'Eclairage (CIE) (x, y) co-ordinates from (0.149, 0.175) to (0.145, 0.123) whilst maintaining high efficiency and improving stability. We achieve peak luminous efficiency, η = 3.60 cd/A and luminous power efficiency, ηw = 2.44 lm/W; values that represent state of the art performance for single copolymer deep-blue PLEDs. These values are five-fold better than for otherwise-equivalent, β-phase poly(9,9-dioctylfluorene) (PFO) EML PLEDs (0.70 cd/A and 0.38 lm/W). This report represents the first demonstration of the use of molecular conformation as a vector to control the optoelectronic properties of a fluorene copolymer; previous examples have been confined to homopolymers

    Human Capacity Development to adopt Best Practices

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    The concept of capacity development, which emerged during the 1980s, gained prominence in the 1990s and currently has wide usage in community development (Eade, 1997; UNDP, 1998; Bolger, 2000). The term capacity development is usually discussed as an approach to development and cooperation. Capacity development encompasses human resource development as an essential part of development (FAO, 1998). It is a process by which individuals, groups, organizations and societies enhance their abilities to identify and meet development challenges in a sustainable manner (UNDP, 1998). It is human resource development, which is a process of equipping individuals with the understanding of access to information, knowledge, training and skills that enables them to perform effectively. There is a direct relationship between capacity building and agricultural education..

    Improving water use in tropical rain-fed systems: the situation in India Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India

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    Providing global food security for an ever-growing population, predicted to reach nine billion by 2050, and reducing poverty are challenging tasks. Growing per capita income in the emerging giant economies such as Brazil, Russia, India, China and South Africa (BRICS) means increased pressure on global food production due to changing food habits. This increased food production has to be met using finite water and land resources. The quantity of available water and land has not increased since 1950, but the availability of water and land per capita has declined significantly due to an increased global human population. For example, in India, per capita water availability has decreased from 5177 m3 in 1951 to 1625 m3 in 2011 due to the population increasing from 361 million in 1951 to 1.15 billion in 2011, which is expected to rise to 1.39 billion by 2025 and 1.64 billion by 2050, with an associated decrease in per capita water availability of 1345 m3 in 2025 and 1140 m3 by 2050 (Wani et al., 2012). The distribution of water and land resources varies in different countries and regions of the world, and the current population is expected to increase rapidly. In this chapter, we analyse the current status of agricultural water use in tropical rain-fed areas, assess the potential and propose a new paradigm to manage agricultural water efficiently by adopting various land, water, nutrient and crop management technologies
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