4,626 research outputs found
Conductive UV-Cured acrylic inks for resistor fabrication: models for their electrical properties
Mozambique Cashew reforms revisited
Cashew policy reforms in Mozambique have been controversial. They are often invoked by critics as an illustration of how agricultural policy reforms supported by international financial institutions may fail to have their intended effects. This paper revisits the reforms and their outcomes almost two decades later. While the reforms resulted in higher producer prices and an increase in output, lack of consensus on the specifics of the reforms and associated non-price support arrangements created a situation in which the sector was not able to withstand international price shocks that ultimately led to a collapse of both the processing industry and cashew production. Non-price support by donors improved the efficiency of the processing industry but this was not complemented by an expansion in cashew nut supply as such support did not extend to smallholder cashew producers. For the reforms to have had their intended results, greater investment in -- and support to -- smallholder production was needed to increase yields and overall output. Such a more comprehensive approach to cashew policy reform would have required a greater focus on achieving consensus on the causes of the cashew sector's problems and agreement by all stakeholders on a common institutional framework for pricing and non-price support.Markets and Market Access,Emerging Markets,Economic Theory&Research,Access to Markets,E-Business
elastography in primary open-angle glaucoma
Objective: The aim of this study was to compare sonoelastographic findings in the retina-choroid-sclera (RCS) complex and vitreous in glaucomatous and healthy eyes.Methods: For this cross-sectional comparative study, 20 patients with primary open-angle glaucoma and 20 healthy volunteers were recruited. Ultrasound elastography measurements were taken with a sonographic scanner of the RCS complex, anterior vitreous (AV), posterior vitreous (PV), retrobulbar fat tissue (RFT), optic disc (OD) and optic nerve (ON) in each eye.Results: The elasticity index of the RCS complex, RFT, OD, ON, AV and PV was similar in both groups (p > 0.05), although the AV/PV strain ratio in the group of patients with glaucoma was significantly higher (p = 0.04).Conclusion: Glaucoma increases the AV/PV strain ratio. In providing reproducible and consistent values, the real-time elastography (RTE) technique may be helpful in elucidating the mechanisms of glaucoma in some aspects.Advances in knowledge: This study can help to evaluate the elasticity of the RCS complex and vitreous in glaucomatous eyes with RTE
How the Occupy movement may have facilitated political change
Occupy protests are one of the major global political waves of our time. But what was their impact? Alper Yagci highlights the link between the recession, inequality, and the Occupy movement, and writes that although the institutional impact might not have been immediately obvious, the wider political change Occupy facilitated is now becoming clearer
Implementation of a simplified method for actuation of ferrofluids
This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Magnetic actuation of ferrofluids is an emergent field that will open up new possibilities in various fields of engineering. The quality and topology of the magnetic field that is being utilized in such systems is determinant in terms of flow properties, flow rates and overall efficiency. Determining the optimal magnetic
field topology to achieve the desired results, and determining the methods by which these magnetic fields are to be generated are central problems of obtaining the desired flow. A healthy comparison of various magnetic field topologies requires a varied set of examples from the most simplified to most sophisticated. Such comparisons are necessary to have a well grounded starting point. This study focuses on a particular pump design that employs a simplified magnetic field topology to obtain ferrofluid flow. The results of this paper such as flow and pressure difference are intended to form a baseline for future reference.Sabancı University Internal Research Grant, no: IACF09-0064
Estimating Evapotranspiration from Satellite Using Easily Obtainable Variables: A Case Study over the Southern Great Plains, U.S.A.
Evapotranspiration (ET) is a critical component of the Earth's water budget, a critical modulator of land-atmosphere (L-A) interactions, and also plays a crucial role in managing the Earth's energy balance. In this study, the feasibility of generating spatially-continuous daily evaporative fraction (EF) and ET from minimal remotely-sensed and meteorological inputs in a trapezoidal framework is demonstrated. A total of four variables, Normalized Difference Vegetation Index (NDVI), Land surface temperature (T(sub s)), gridded daily average temperature (T(sub a)) and elevation (z) are required to estimate EF. Then, ET can be estimated with the available soil heat flux (G) and net radiation (Rn) data. Firstly, the crucial model variable, T(sub s)-T(sub a), is examined how well it characterizes the variation in EF using in situ data recorded at two eddy correlation flux towers in Southern Great Plains, U.S.A. in 2011. Next, accuracy of satellite-based T(sub s) are compared to ground-based T(sub s). Finally, EF and ET estimates are validated. The results reveal that the model performed satisfactorily in modeling EF and ET variation at winter wheat and deciduous forest during the high evaporative months. Even though the model works best with the observed MODIS-T(sub s) as opposed to temporally interpolated T(sub s), results obtained from interpolated T(sub s) are able to close the gaps with reasonable accuracy. Due to the fact that T(sub s)-T(sub a), is not a good indicator of EF outside the growing season when deciduous forest is dormant, potential improvements to the model are proposed to improve accuracy in EF and ET estimates at the expense of adding more variables
SIP1 is downregulated in hepatocellular carcinoma by promoter hypermethylation
Background: Smad interacting protein-1 is a transcription factor that is implicated in transforming growth factor-β/bone morphogenetic protein signaling and a repressor of E-cadherin and human telomerase reverse transcriptase. It is also involved in epithelial-mesenchymal transition and tumorigenesis. However, genetic and epigenetic alterations of SIP1 have not been fully elucidated in cancers. In this study, we investigated mutations and promoter hypermethylation of the SIP1 gene in human hepatocellular carcinomas.Methods: SIP1 expression was analyzed in HCC cell lines and primary tumors in comparison to normal and non-tumor liver tissues by using semi-quantitative RT-PCR, quantitative real-time RT-PCR and immunohistochemistry. Mutation and deletion screening of the SIP1 gene were performed by direct sequencing in HCC-derived cells. Restoration of SIP1 expression was sought by treating HCC cell lines with the DNA methyl transferase inhibitor, 5-AzaC, and the histone deacetylase inhibitor, TSA. SIP1 promoter methylation was analyzed by the combined bisulfite restriction analysis assay in in silico-predicted putative promoter and CpG island regions.Results: We found that the expression of SIP1 was completely lost or reduced in five of 14 (36%) HCC cell lines and 17 of 23 (74%) primary HCC tumors. Immunohistochemical analysis confirmed that SIP1 mRNA downregulation was associated with decreased expression of the SIP1 protein in HCC tissues (82.8%). No somatic mutation was observed in SIP1 exons in any of the 14 HCC cell lines. Combined treatment with DNA methyl transferase and histone deacetylase inhibitors synergistically restored SIP1 expression in SIP1-negative cell lines. Analysis of three putative gene regulatory regions revealed tumor-specific methylation in more than half of the HCC cases.Conclusions: Epigenetic mechanisms contribute significantly to the downregulation of SIP1 expression in HCC. This finding adds a new level of complexity to the role of SIP1 in hepatocarcinogenesis. © 2011 Acun et al; licensee BioMed Central Ltd
In Situ Synthesis of Polymer/Clay Nanocomposites by Type II Photoinitiated Free Radical Polymerization
Cataloged from PDF version of article.A new synthetic route for the preparation of poly(methyl methacrylate)/montmorillonite (PMMA/MMT) nanocomposites was reported. In this method, first 4-(dimethylamino)benzoate group was incorporated into silicate layers of clay by esterification reaction and used to produce PMMA/MMT nanocomposites by in situ Type II photoinitiated free radical polymerization. In situ photopolymerization of methyl methacrylate through into the silicate layers by either visible or UV light irradiation leads to PMMA/MMT nanocomposites. Copyright © 2011 Wiley Periodicals, Inc
Self-aligned and bundled electrospun fibers prepared from blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairt-rod polyphenylene copolymer
Cataloged from PDF version of article.Bundled and self-aligned fibers were obtained by electrospinning blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairy-rod polyphenylene-g-polystyrene/poly(a-caprolactone) (PP-g-PS/PCL) copolymer. The self-alignment and bundling characteristics of these electrospun fibers were ascribed to the unique molecular architecture of the conjugated polymer, PP-g-PS/PCL, and its interactions with the solvent and the polymer matrixes used for the electrospinning. The self-alignment and bundling was found to be much more pronounced for PP-g-PS/PCL-PS blend when compared to PP-g-PS/PCL-PMMA blend. Furthermore we found that the degree of self-alignment of the fiber bundles was enhanced by increasing the amount of PP-g-PS/PCL in the blends but the alignment completely disappeared when the solvent dimethylformamide was changed to chloroform. © 2009 Elsevier B.V. All rights reserved
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