737 research outputs found
Development of a scalable generic platform for adaptive optics real time control
The main objective of the present project is to explore the viability of an
adaptive optics control system based exclusively on Field Programmable Gate
Arrays (FPGAs), making strong use of their parallel processing capability. In
an Adaptive Optics (AO) system, the generation of the Deformable Mirror (DM)
control voltages from the Wavefront Sensor (WFS) measurements is usually
through the multiplication of the wavefront slopes with a predetermined
reconstructor matrix. The ability to access several hundred hard multipliers
and memories concurrently in an FPGA allows performance far beyond that of a
modern CPU or GPU for tasks with a well defined structure such as Adaptive
Optics control. The target of the current project is to generate a signal for a
real time wavefront correction, from the signals coming from a Wavefront
Sensor, wherein the system would be flexible to accommodate all the current
Wavefront Sensing techniques and also the different methods which are used for
wavefront compensation. The system should also accommodate for different data
transmission protocols (like Ethernet, USB, IEEE 1394 etc.) for transmitting
data to and from the FPGA device, thus providing a more flexible platform for
Adaptive Optics control. Preliminary simulation results for the formulation of
the platform, and a design of a fully scalable slope computer is presented.Comment: Paper presented as part of SPIE ICOP 2015 Conference Proceeding
Safety Guidelines for Drivers of CMFRI സി.എം.എഫ്.ആർ.ഐ. ഡ്രൈവർമാർക്കുള്ള സുരക്ഷാ മാർഗ്ഗനിർദ്ദേശങ്ങൾ
Safety Guidelines for Drivers of CMFRI
സി.എം.എഫ്.ആർ.ഐ. ഡ്രൈവർമാർക്കുള്ള സുരക്ഷാ മാർഗ്ഗനിർദ്ദേശങ്ങ
Molecular characterization of the malaria vector Anopheles barbirostris van der Wulp in Sri Lanka
Background: Anopheles barbirostris is a vector of malaria in Sri Lanka. The taxon exists as a species complex in the Southeast Asian region. Previous studies using molecular markers suggest that there are more than 4 distinct clades within the An. barbirostris complex in Southeast Asia. The present study characterizes Sri Lankan An. barbirostris using mtDNA cytochrome oxidase subunit I (COI) and ribosomal RNA internal transcribed spacer 2 (ITS2) gene sequences.
Findings: DNA was extracted from morphologically identified An. barbirostris specimens from Sri Lanka, the COI and ITS2 regions amplified and their sequences analysed by comparison with other GenBank entries. Maximum likelihood trees suggested that Sri Lankan An. barbirostris constitute a different molecular type most closely related to clade I.
Conclusions: Considering the uncorrected p distances between the clade I and Sri Lankan specimens it is fair to assume that the specimens collected from widely separated locations in Sri Lanka with morphology characteristic of An. barbirostris s.l. form a new molecular type with close resemblance to An. barbirostris s.s from Indonesia and Thailand
Gene targets of mouse miR-709: regulation of distinct pools
MicroRNA (miRNA) are short non-coding RNA molecules that regulate multiple cellular processes, including development, cell differentiation, proliferation and death. Nevertheless, little is known on whether miRNA control the same gene networks in different tissues. miR-709 is an abundant miRNA expressed ubiquitously. Through transcriptome analysis, we have identified targets of miR-709 in hepatocytes. miR-709 represses genes implicated in cytoskeleton organization, extracellular matrix attachment, and fatty acid metabolism. Remarkably, none of the previously identified targets in non-hepatic tissues are silenced by miR-709 in hepatocytes, even though several of these genes are abundantly expressed in liver. In addition, miR-709 is upregulated in hepatocellular carcinoma, suggesting it participates in the genetic reprogramming that takes place during cell division, when cytoskeleton remodeling requires substantial changes in gene expression. In summary, the present study shows that miR-709 does not repress the same pool of genes in separate cell types. These results underscore the need for validating gene targets in every tissue a miRNA is expressed
Molecular characterization and identification of members of the Anopheles subpictus complex in Sri Lanka
BACKGROUND: Anopheles subpictus sensu lato is a major malaria vector in South and Southeast Asia. Based initially on polytene chromosome inversion polymorphism, and subsequently on morphological characterization, four sibling species A-D were reported from India. The present study uses molecular methods to further characterize and identify sibling species in Sri Lanka. METHODS: Mosquitoes from Sri Lanka were morphologically identified to species and sequenced for the ribosomal internal transcribed spacer-2 (ITS2) and the mitochondrial cytochrome c oxidase subunit-I (COI) genes. These sequences, together with others from GenBank, were used to construct phylogenetic trees and parsimony haplotype networks and to test for genetic population structure. RESULTS: Both ITS2 and COI sequences revealed two divergent clades indicating that the Subpictus complex in Sri Lanka is composed of two genetically distinct species that correspond to species A and species B from India. Phylogenetic analysis showed that species A and species B do not form a monophyletic clade but instead share genetic similarity with Anopheles vagus and Anopheles sundaicus s.l., respectively. An allele specific identification method based on ITS2 variation was developed for the reliable identification of species A and B in Sri Lanka. CONCLUSION: Further multidisciplinary studies are needed to establish the species status of all chromosomal forms in the Subpictus complex. This study emphasizes the difficulties in using morphological characters for species identification in An. subpictus s.l. in Sri Lanka and demonstrates the utility of an allele specific identification method that can be used to characterize the differential bio-ecological traits of species A and B in Sri Lanka
Possible impact of rising sea levels on vector-borne infectious diseases
<p>Abstract</p> <p>Background</p> <p>Vector-borne infectious diseases are a significant cause of human and animal mortality and morbidity. Modeling studies predict that changes in climate that accompany global warming will alter the transmission risk of many vector-borne infectious diseases in different parts of the world. Global warming will also raise sea levels, which will lead to an increase in saline and brackish water bodies in coastal areas. The potential impact of rising sea levels, as opposed to climate change, on the prevalence of vector-borne infectious diseases has hitherto been unrecognised.</p> <p>Presentation of the hypothesis</p> <p>Mosquito species possessing salinity-tolerant larvae and pupae, and capable of transmitting arboviruses and parasites are found in many parts of the world. An expansion of brackish and saline water bodies in coastal areas, associated with rising sea levels, can increase densities of salinity-tolerant vector mosquitoes and lead to the adaptation of freshwater vectors to breed in brackish and saline waters. The breeding of non-mosquito vectors may also be influenced by salinity changes in coastal habitats. Higher vector densities can increase transmission of vector-borne infectious diseases in coastal localities, which can then spread to other areas.</p> <p>Testing the hypothesis</p> <p>The demonstration of increases in vector populations and disease prevalence that is related to an expansion of brackish/saline water bodies in coastal areas will provide the necessary supportive evidence. However the implementation of specific vector and disease control measures to counter the threat will confound the expected findings.</p> <p>Implications of the hypothesis</p> <p>Rising sea levels can act synergistically with climate change and then interact in a complex manner with other environmental and socio-economic factors to generate a greater potential for the transmission of vector-borne infectious diseases. The resulting health impacts are likely to be particularly significant in resource-poor countries in the tropics and semi-tropics. Some measures to meet this threat are outlined.</p
Exact Haldane mapping for all S and super universality in spin chains
The low-energy dynamics of the anti-ferromagnetic Heisenberg spin S chain in the semiclassical limit S -> infinity is known to map onto the O(3) nonlinear alpha-model with a theta term in 1 + 1 dimension. Guided by the underlying dual symmetry of the spin chain, as well as by the recently established topological significance of "dangling edge spins", we report an exact mapping onto the O(3) model that avoids the conventional large-S approximation altogether. Our new methodology demonstrates all the super universal features of the theta-angle concept that previously arose in the theory of the quantum Hall effect. It explains why Haldane's original ideas remarkably yield the correct answer in spite of the fundamental complications that generally exist in the idea of semiclassical expansions
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