78 research outputs found

    Video data compression using artificial neural network differential vector quantization

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    An artificial neural network vector quantizer is developed for use in data compression applications such as Digital Video. Differential Vector Quantization is used to preserve edge features, and a new adaptive algorithm, known as Frequency-Sensitive Competitive Learning, is used to develop the vector quantizer codebook. To develop real time performance, a custom Very Large Scale Integration Application Specific Integrated Circuit (VLSI ASIC) is being developed to realize the associative memory functions needed in the vector quantization algorithm. By using vector quantization, the need for Huffman coding can be eliminated, resulting in superior performance against channel bit errors than methods that use variable length codes

    Change in lattice parameter of tantalum due to dissolved hydrogen

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    The volume expansion of tantalum due to the dissolved hydrogen has been determined using Bragg equation. The hydrogen was dissolved in the pure tantalum metal at constant temperature (360 °C) and constant pressure (132 mbar) by varying the duration of hydrogen charging. The amount of dissolved hydrogen was within the solid solubility limit. The samples with different hydrogen concentration were analyzed by X-ray diffraction technique. Slight peak shifts as well as peak broadening were observed. The relative changes of lattice parameters plotted against the hydrogen concentration revealed that the lattice parameters varied linearly with the hydrogen concentration

    Diverting intracellular trafficking of Salmonella to the lysosome through activation of the late endocytic Rab7 by intracellular delivery of muramyl dipeptide

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    Previously, we showed that live Salmonella-containing phagosomes (LSP) recruit early acting Rab5 and promote fusion with early endosomes, thus avoiding transport to the lysosomes. Therefore, live Salmonella survive in a specialized compartment. Here we show that scavenger-receptor-mediated intracellular delivery of muramyl dipeptide (MDP) to macrophages leads to efficient killing of Salmonella both in vitro and in vivo. To understand the intracellular trafficking modulation of Salmonella by delivery of MDP, we investigated the levels of endocytic Rab proteins, which are the major regulators of vesicular transport. Western blot analysis reveals reduced Rab5 and enhanced Rab7 content in the maleylated bovine serum albumin-MDP (MBSA-MDP)-treated cells. The reduced content of Rab5 in the treated cells and on phagosomes inhibits the fusion of Salmonella-containing phagosomes with early endosomes, and the enhanced Rab7 content in these cells facilitated targeting of LSP to lysosomes, which contain cathepsin D and vacuolar ATPase, for killing. In vitro reconstitution of lysosomal transport demonstrated that a reduced content of Rab5 and an enhanced level of Rab7 in MBSA-MDP-treated cells is primarily responsible for targeting Salmonella to lysosomes. Intracellular delivery of MDP thus offers a general strategy against macrophage-associated infections caused by intracellular pathogens that survive in the host cell by resisting transport to lysosomes

    Privacy preserving interactive record linkage (PPIRL)

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    Record linkage to integrate uncoordinated databases is critical in biomedical research using Big Data. Balancing privacy protection against the need for high quality record linkage requires a human–machine hybrid system to safely manage uncertainty in the ever changing streams of chaotic Big Data

    Age for measles immunization seroconversion after measles vaccination at 6-8 months of age - A randomised controlled trial

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    The, objective of the study was to compare the effectiveness of measles vaccine by seroconversion in vaccinated children with non-vaccinated children of 6 to 8 months age group in a city slam community so as to study the feasibility of advancing the age of immunization. Live attenuated lyophilized Schwartz strain of measles vaccine was used. Hemagglutination inhibition (HI) antibody was estimated. Seroconversion was defined as either the conversion of negative to positive or a two fold rise in titre. One hundred and thirty two children completed the study. There was no difference in the age, sex and nutritional status between vaccinated and non-vaccinated groups (p>0.7). The seroconversion rate in the vaccinated group was 65% and in the non-vaccinated group was 26%. The age, sex and nutritional status did not significantly affect the seroconversion. Oar data suggest that immunization with measles vaccine may be effective as early as 6 months of age. Immunization at 6 months may be needed at least for children in densely populated areas like cities and towns

    Nanocomposite cotton fabrics with in situ formed copper nanoparticles using citrus lemon leaf extract as reducing agent

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    Nanocomposite cotton fabrics (NCCFs) with in situ formed copper nanoparticles (CuNPs) using aqueous extraction of citrus lemon leaves as reducing agent have been made. The NCCFs have been analyzed by SEM, FTIR, XRD and TGA techniques and antibacterial test. The CuNPS have been roughly spherical in shape with a mean size in the range of 82-114 nm. The OH and C-OH groups of leaf extract has played an important role in the generation of the CuNPs in the NCCFs as established by the FTIR spectral analysis. The XRD analysis has indicated that the formation of CuNPs in NCCFs lowered the crystallinity of NCCFs. The thermal stability of NCCFs has been lowered by the CuNPs. However, the NCCFs with in situ generated CuNPs exhibited higher antibacterial activity against both gram-negative and gram-positive bacteria and hence can be effectively used as antibacterial wound dressing and hospital bed materials

    Clinical Implications of Mutations at Reverse Transcriptase Codon 135 on Response to NNRTI-Based Therapy

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    To evaluate the impact of mutations at reverse transcriptase codon 135 on treatment outcomes in patients receiving NNRTI-based antiretroviral therapy, a total of 68 patients (30 with and 38 without baseline mutations at codon 135) were evaluated. Median increases in CD4 counts were 135 and 90 cells/mm3 (p=0.32), virologic suppression (HIV RNA < 400 copies/mL) was achieved in 16 (53%) and 16 (42%) patients (p=0.50), while NNRTI resistance was detected in 10/14 (71%) and 16/22 (73%) in patients with and without mutations at codon 135, respectively. Patients who experienced a virologic breakthrough and had a baseline mutation at codon 135 were more likely to evolve a single NNRTI resistance mutation (8/14 vs 4/22, p=0.029) but less likely to evolve multiple NNRTI resistance mutations (2/14 vs 12/22, p = 0.033). Mutations at codon 135 do not affect response rates, but affect the pattern of development of NNRTI resistance mutations. This has important implications for the subsequent use of newer NNRTIs such as etravirine in salvage therapy

    The resolution sensitivity of the South Asian monsoon and Indo-Pacific in a global 0.35â—¦ AGCM

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    The South Asian monsoon is one of the most significant manifestations of the seasonal cycle. It directly impacts nearly one third of the world’s population and also has substantial global influence. Using 27-year integrations of a high-resolution atmospheric general circulation model (Met Office Unified Model), we study changes in South Asian monsoon precipitation and circulation when horizontal resolution is increased from approximately 200 to 40 km at the equator (N96 to N512, 1.9 to 0.35◦). The high resolution, integration length and ensemble size of the dataset make this the most extensive dataset used to evaluate the resolution sensitivity of the South Asian monsoon to date. We find a consistent pattern of JJAS precipitation and circulation changes as resolution increases, which include a slight increase in precipitation over peninsular India, changes in Indian and Indochinese orographic rain bands, increasing wind speeds in the Somali Jet, increasing precipitation over the Maritime Continent islands and decreasing precipitation over the northern Maritime Continent seas. To diagnose which resolution related processes cause these changes we compare them to published sensitivity experiments that change regional orography and coastlines. Our analysis indicates that improved resolution of the East African Highlands results in the improved representation of the Somali Jet and further suggests that improved resolution of orography over Indochina and the Maritime Continent results in more precipitation over the Maritime Continent islands at the expense of reduced precipitation further north. We also evaluate the resolution sensitivity of monsoon depressions and lows, which contribute more precipitation over northeast India at higher resolution. We conclude that while increasing resolution at these scales does not solve the many monsoon biases that exist in GCMs, it has a number of small, beneficial impacts

    Predicting the seasonal evolution of southern African summer precipitation in the DePreSys3 prediction system

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    We assess the ability of the DePreSys3 prediction system to predict austral summer precipitation (DJF) over southern Africa, defined as the African continent south of 15°S. DePresys3 is a high resolution prediction system (at a horizontal resolution of ~ 60 km in the atmosphere in mid-latitudes and of the quarter degree in the Ocean) and spans the long period 1959–2016. We find skill in predicting interannual precipitation variability, relative to a long-term trend; the anomaly correlation skill score over southern Africa is greater than 0.45 for the first summer (i.e. lead month 2–4), and 0.37 over Mozambique, Zimbabwe and Zambia for the second summer (i.e. lead month 14–16). The skill is related to the successful prediction of the El-Nino Southern Oscillation (ENSO), and the successful simulation of ENSO teleconnections to southern Africa. However, overall skill is sensitive to the inclusion of strong La-Nina events and also appears to change with forecast epoch. For example, the skill in predicting precipitation over Mozambique is significantly larger for the first summer in the 1990–2016 period, compared to the 1959–1985 period. The difference in skill in predicting interannual precipitation variability over southern Africa in different epochs is consistent with a change in the strength of the observed teleconnections of ENSO. After 1990, and consistent with the increased skill, the observed impact of ENSO appears to strengthen over west Mozambique, in association with changes in ENSO related atmospheric convergence anomalies. However, these apparent changes in teleconnections are not captured by the ensemble-mean predictions using DePreSys3. The changes in the ENSO teleconnection are consistent with a warming over the Indian Ocean and modulation of ENSO properties between the different epochs, but may also be associated with unpredictable atmospheric variability
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