87 research outputs found
How to make agricultural extension demand-driven?: The case of India's agricultural extension policy
No full text"Many countries have recognized the need to revive agricultural advisory or extension services (the terms are used interchangeably here) as a means of using agriculture as an engine of pro-poor growth; reaching marginalized, poor, and female farmers; and addressing new challenges, such as environmental degradation and climate change. In spite of ample experience with extension reform worldwide, identifying the reform options most likely to make extension more demand-driven remains a major challenge. The concept of demand-driven services implies making extension more responsive to the needs of all farmers, including women and those who are poor and marginalized. It also implies making extension more accountable to farmers and, as a consequence, more effective. This essay discusses various options for providing and financing agricultural advisory services, which involve the public and private sectors as well as a third sector comprising nongovernmental organizations and farmer-based organizations. We review the market and state failures, and the “community” failures (failures of non-governmental and farmer-based organizations) inherent in existing models of providing and financing agricultural extension services and then outline strategies to address those failures and make extension demand-driven. Then we examine India's Policy Framework for Agricultural Extension, which has demand-driven extension as one of its major objectives, and review available survey information on the state of extension in India. We conclude that although the framework proposes a wide range of strategies to make agricultural extension demand-driven, it is less specific in addressing the challenges inherent in those strategies. Moreover, it remains unclear whether the strategies proposed in the framework will be able to address one of the major problems identified by farm household surveys: access to agricultural extension." from Authors' AbstractDemand-driven agricultural advisory services, Extension reform, Agricultural extension work, Agricultural policy, Pro-poor growth, Farmers, Environmental degradation, Climate change, Public-private sector cooperation, Non-governmental organizations,
β-Ulam stability results for Atangana–Baleanu–Caputo fractional equations with non-instantaneous impulsive boundary conditions
No full textNumerous fixed point theorems (FPTs) are crucial for scientific research in the domains of engineering and science. The main goal of this article is to examine the β-Ulam-Hyers stability for non-instantaneous impulsive fractional integro-differential equations with Atangana–Baleanu–Caputo (AB-Caputo) fractional derivative in a Banach space. Moreover, Banach Contraction Mapping Principle (BCMP) and Krasnoselskii fixed point theorems (KFPT) are utilized to prove the uniqueness and existence theorems. At the end, an example is discussed to validate the analytical result. Thus, we generalize a number of previous results
A component-based middleware framework for configurable and reconfigurable Grid computing
No full textSignificant progress has been made in the design and development of Grid middleware which, in its present form, is founded on Web services technologies. However, we argue that present-day Grid middleware is severely limited in supporting projected next-generation applications which will involve pervasive and heterogeneous networked infrastructures, and advanced services such as collaborative distributed visualization. In this paper we discuss a new Grid middleware framework that features (i) support for advanced network services based on the novel concept of pluggable overlay networks, (ii) an architectural framework for constructing bespoke Grid middleware platforms in terms of 'middleware domains' such as extensible interaction types and resource discovery. We believe that such features will become increasingly essential with the emergence of next-generation e-Science applications. Copyright (c) 2005 John Wiley & Sons, Ltd
Realization of aligned three-dimensional single-crystal chromium nanostructures by thermal evaporation
No full textAligned three-dimensional single-crystal chromium nanostructures are fabricated onto a silicon substrate by thermal evaporation in a conventional thermal evaporator, where the incident angle of Cr vapor flux with respect to the substrate surface normal is fixed at 88°. The effects of the deposition time and incident angle on the morphology of the resulting nanostructures are investigated. The achieved Cr nanostructures are characterized by scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and surface area measurement. This study provides a convenient way to fabricate three-dimensional single-crystal Cr nanostructures, which is suitable for batch fabrication and mass production. Finally, the same technique is employed to fabricate the nanostructures of other metals such as Ag, Au, Pd, and Ni
GRIDKIT: Pluggable overlay networks for Grid computing
No full textA `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks
Supplementary Material for: Biochemical and Pharmacokinetic Properties of PEGylated Cystathionine γ-Lyase from <b><i>Aspergillus carneus</i></b> KF723837
No full textCystathionine γ-lyase (CGL) was purified to its electrophoretic homogeneity from Aspergillus carneus by various chromatographic approaches. The purified enzyme has four identical subunits of 52 kDa based on SDS and native PAGE analyses. To improve its structural stability, purified CGL was modified by covalent binding to polyethylene glycol moieties. The specific activity of free-CGL and PEG-CGL was 59.71 and 48.71 U/mg, respectively, with a PEGylation yield of 81.5 and 70.7% modification of surface ε-amino groups. Free- and modified CGL have the same pattern of pH stability (8.0-9.0). At 50°C, the thermal stability [half-life time (T1/2)] of PEG-CGL was increased by 40% in comparison to free-CGL. The activity of CGL was completely inhibited by hydroxylamine and Hg+2, with no effect by EDTA. Free-CGL (0.04 mM-1s-1) and PEG-CGL (0.03 mM-1s-1) have a similar catalytic efficiency to L-cystathionine as a substrate. The inhibition constant values of propargylglycine were 0.31 and 0.52 µM for the free- and PEG-CGL, respectively. By in vitro proteolysis, PEG-CGL retains >50% of its initial activity compared to 1/2 was 19.1 and 28.9 h for the Holo free-CGL and PEG-CGL, respectively, ensuring the role of PEGylation on shielding the CGL surface from proteolytic attack, reducing its antigenicity, and stabilizing its internal Schiff base. By external infusion of pyridoxal 5′-phosphate (10 µM), the T1/2 of free- and PEG-CGL was prolonged to 24 and 33 h, respectively, so dissociation of pyridoxal 5′-phosphate was one of the main causes of loss of enzyme activity. The biochemical and hematological responses of rabbits to free- and PEG-CGL were assessed, with relative similarity to the negative control, confirming the nil toxicity of enzymes. The titer of IgG was duplicated in response to free- versus PEG-CGL after 45 days. To the best of our knowledge, this is the first report concerned with purification and PEGylation of CGL from fungi, with higher affinity for L-cystathionine. With further molecular studies, CGL will be a promising enzyme against various cardiovascular diseases and antioxidant deficiency, as well as for generation of a neurotransmitter (H2S)
Development of new fluorescent silica and multifunctional nanoparticles for bio-imaging and diagnostics
No full textSilica nanoparticles are effective fluorophore carriers with high potential in
imaging, diagnostics, and therapy. The particles are resistant to drastic change
of environmental conditions (pH, temperature etc. and insulate the dyes so as to
protect them from photobleaching. Silica chemistry is also versatile and affords
an easy modification of the particle composition and surface to integrate
targeting ligands or to integrate other nanoparticles. Regardless of their
advantages, there exists a lack of dye diversity in the literature that is connected
to a low affinity for
potential tools for biology and medicineThis thesis describes the development
of an alternative method for the synthesis of fluorescent silica nanoparticles and
their modification to incorporate iron oxide and gold. cont/d
The system of genetic exchange in <i>Trypanosoma brucei</i> and other trypanosomatids
No full textIn this chapter, we discuss our current understanding of the systems of genetic exchange in trypanosomatids and the im-pact the recent genome projects have had on this area of research. We focus mainly on the details of Trypanosoma brucei as it is the most extensively studied of the “trityps”, but will also refer to a recently discovered novel mechanism of genetic exchange in T. cruzi and the apparent rarity of genetic ex-change in Leishmania sp.The system of genetic exchange in Trypanosoma brucei has been known to exist since the late eighties when a genetic cross between different strains was carried out by co-transmission through the tsetse fly. We discuss the segregation of nuclear, chromosomal and kDNA markers and outline the two current models for the mechanism of genetic exchange. We also present how the completion of the genome project has allowed the identification of polymorphic micro and minisatel-lite markers distributed throughout the genome, which have been used to prove formally that meiosis, independent assortment and crossing over occur in this para-site, as would be predicted in a conventional Mendelian system. Such data have been used to construct the first genetic map of T. brucei, which opens up the use of genetic analysis, coupled with positional cloning and the genome sequence, as a tool to identify the genes involved in a range of traits relevant to the disease
Numerical Modeling of Plasmonic Nanoantennas with Realistic 3D Roughness and Distortion
No full textNanostructured plasmonic metamaterials, including optical nanoantenna arrays, are important for advanced optical sensing and imaging applications including surface-enhanced fluorescence, chemiluminescence, and Raman scattering. Although designs typically use ideally smooth geometries, realistic nanoantennas have nonzero roughness, which typically results in a modified enhancement factor that should be involved in their design. Herein we aim to treat roughness by introducing a realistic roughened geometry into the finite element (FE) model. Even if the roughness does not result in significant loss, it does result in a spectral shift and inhomogeneous broadening of the resonance, which could be critical when fitting the FE simulations of plasmonic nanoantennas to experiments. Moreover, the proposed approach could be applied to any model, whether mechanical, acoustic, electromagnetic, thermal, etc, in order to simulate a given roughness-generated physical phenomenon
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