47 research outputs found

    A 9-Bit Flash Analog to Digital Convertor

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    Need constantly exists for converters with higher resolution, faster conversion speed and lower power dissipation. High-speed analog to digital converters (ADC’s) have been based on flash architecture, because all comparators sample the analog input voltage simultaneously, this ADC is thus inherently fast. Unfortunately, flash ADC requires 2N - 1 comparators to convert N bit digital code from an analog sample. This makes flash ADC’s unsuitable for high-resolution applications. This paper demonstrates a simple technique to reduce comparator requirement of 9-bit flash ADC that requires as few as 256 comparators for 9-bit conversion. In this approach, the analog input range is partitioned into 256 quantization cells, separated by 255 boundary points. A 8-bit binary code 00000000 to 11111111 is assigned to each cell. A 9-bit flash converter requires 512 comparators, while proposed technique reduces number of comparator requirements to 256 for 9-bit conversion

    Effect of Stress on Viral–Bacterial Synergy in Bovine Respiratory Disease: Novel Mechanisms to Regulate Inflammation

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    The severity of bovine respiratory infections has been linked to a variety offactors, including environmental and nutritional changes, transportation, and socialreorganization of weaned calves. Fatal respiratory infections, however, usually occurwhen a primary viral infection compromises host defences and enhances the severityof a secondary bacterial infection. This viral–bacterial synergy can occur by a numberof different mechanisms and disease challenge models have been developed to analysehost responses during these respiratory infections. A primary bovine herpesvirus-1(BHV-1) respiratory infection followed by a secondary challenge with Mannheimia haemolyticaresults in fatal bovine respiratory disease (BRD) and host responses to these two pathogens have been studied extensively. We used this disease model todemonstrate that stress significantly altered the viral–bacterial synergy resulting infatal BRD. Functional genomic analysis revealed that BHV-1 infection enhanced toll-likereceptors (TLR) expression and increased pro-inflammatory responses whichcontribute to the severity of a Mannheimia haemolytica infection. TLRs play a criticalrole in detecting bacterial infections and inducing pro-inflammatory responses. It isdifficult to understand, however, how stress-induced corticosteroids could enhancethis form of viral–bacterial synergy. Nuclear translocation of the glucocorticoidreceptor activates cell signalling pathways which inhibit both TLR signallingand pro-inflammatory responses. The apparent conundrum between stress-inducedcorticosteroids and enhanced BRD susceptibility is discussed in terms of present data and previous investigations of stress and respiratory disease

    Development of a pipeline for exploratory metabolic profiling of infant urine

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    Numerous metabolic profiling pipelines have been developed to characterize the composition of human biofluids and tissues, the vast majority of these being for studies in adults. To accommodate limited sample volume and to take into account the compositional differences between adult and infant biofluids, we developed and optimized sample handling and analytical procedures for studying urine from newborns. A robust pipeline for metabolic profiling using NMR spectroscopy was established, encompassing sample collection, preparation, spectroscopic measurement, and computational analysis. Longitudinal samples were collected from five infants from birth until 14 months of age. Methods of extraction and effects of freezing and sample dilution were assessed, and urinary contaminants from breakdown of polymers in a range of diapers and cotton wool balls were identified and compared, including propylene glycol, acrylic acid, and tert-butanol. Finally, assessment of urinary profiles obtained over the first few weeks of life revealed a dramatic change in composition, with concentrations of phenols, amino acids, and betaine altering systematically over the first few months of life. Therefore, neonatal samples require more stringent standardization of experimental design, sample handling, and analysis compared to that of adult samples to accommodate the variability and limited sample volume

    Effect of Stress on Viral–Bacterial Synergy in Bovine Respiratory Disease: Novel Mechanisms to Regulate Inflammation

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    The severity of bovine respiratory infections has been linked to a variety of factors, including environmental and nutritional changes, transportation, and social reorganization of weaned calves. Fatal respiratory infections, however, usually occur when a primary viral infection compromises host defences and enhances the severity of a secondary bacterial infection. This viral–bacterial synergy can occur by a number of different mechanisms and disease challenge models have been developed to analyse host responses during these respiratory infections. A primary bovine herpesvirus-1 (BHV-1) respiratory infection followed by a secondary challenge with Mannheimia haemolytica results in fatal bovine respiratory disease (BRD) and host responses to these two pathogens have been studied extensively. We used this disease model to demonstrate that stress significantly altered the viral–bacterial synergy resulting in fatal BRD. Functional genomic analysis revealed that BHV-1 infection enhanced toll-like receptors (TLR) expression and increased pro-inflammatory responses which contribute to the severity of a Mannheimia haemolytica infection. TLRs play a critical role in detecting bacterial infections and inducing pro-inflammatory responses. It is difficult to understand, however, how stress-induced corticosteroids could enhance this form of viral–bacterial synergy. Nuclear translocation of the glucocorticoid receptor activates cell signalling pathways which inhibit both TLR signalling and pro-inflammatory responses. The apparent conundrum between stress-induced corticosteroids and enhanced BRD susceptibility is discussed in terms of present data and previous investigations of stress and respiratory disease

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

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    Not AvailableTrypanosoma evansi, the causative agent of surra, is pathogenic to a wide variety of wild and domestic animals, including equines, camels, goats, sheep, cattle, buffaloes, pigs, dogs, tigers, elephants etc. The infection is mainly restricted to animals but ability to infect human beings has also been reported due to the lack of efficient apolipoprotein L 1. The parasite is mechanically transmitted by blood-sucking flies such as Tabanus and Stomoxys species. The disease has a major economic impact in tropical countries. The control of trypanosomosis may be aimed either at the fly or against the parasite. Due to difficulties in large scale fly control, trypanocides have been widely used to control the disease. However, current chemotherapeutic agents are limited in number and usually associated with severe side effects. Moreover, current therapeutic agents are far from ideal. The emergence of drug resistant trypanosomes …Not Availabl

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    Not AvailableOne hundred and forty two fecal samples were screened to establish the diversity of parasites in neonatal buffalo calves. Samples were examined by specific techniques including morphometry of oocysts and eggs to ascertain the identity of parasites involved. An overall prevalence of 3.52% was found for Cryptosporidium spp. with the highest infection during peak winters. Incidence of Eimeria spp. infection was the highest during monsoon season with an overall prevalence of 16.10%. Two cases (1.40 %) of Strongyloides papillosus were also recorded during the monsoon season.Not Availabl

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    Not AvailableZinc oxide nanoparticles are important nanomaterials currently under research due to their applicability in nanomedicine. Toxicity of ZnO NPs has been extensively studied and has been shown to affect various cell types and animal systems. In this study, we investigated hemolytic potential and oxidative stress inflicted by ZnO NPs and ZnO NPs-loaded-sodium alginate-gum acacia hydrogels on horse erythrocytes and African green monkey kidney (Vero) cells. Our study provides a better understanding of the hemolytic and oxidative effects of interaction of ZnO NPs and ZnO NPs released from polymeric hydrogels with the biological system. Remarkable aggregation of erythrocytes was noted in the higher concentration of ZnO NPs treated erythrocytes as compared to erythrocytes treated with ZnO NPs-loaded hydrogels. ZnO NPs-loaded hydrogels treated Vero cells significantly reduced oxidative stress as evidenced by less malondialdehyde production as compared to that of ZnO NPs treated cells. Normal horse erythrocytes when treated with ZnO NPs in in vitro condition undergo oxidative damage, and contribute in augmenting the toxicity. We demonstrated that polymeric ZnO NPs reduced the undesirable effects provoked by ZnO NPs on mammalian cells.Not Availabl

    Evaluation of different herbicides for protection of gladiolus( Gladiolus spp.) crop from weeds

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    A field experiment to study the effects of various pre- and post-emergence herbicides on weed infestation and on corm and cormel production in three gladiolus( Gladiolus spp.) cultivars was carried out during 1997–2000 at IHBT, Palampur. The main weeds infesting the experimental farm were Ageratum conyzoides, Gnaphalium peregrinum, Plantago lanceolata, Cynodon dactylon, Amaranthus viridis, Paspalum dilatatum, Portulaca oleracea, Euphorbia hirta, Oxalis corniculata, Trifolium repens, Imperata cylindrica and Digitaria adscendance. Of the variouspre-emergence herbicides tested, atrazine and alachlor, both at 1.0 kg a.i./ha, significantly lowered the germination percentage of the gladiolus cormels. Pendimethalin 1.0 kg a.i./ha reduced the germination of the cormels to a lesser extent. Pre-emergence application of oxyfluorfen 0.25 kg a.i./ha gave the lowest weed count and weed dry matter accumulation, comparable with weed free treatment, at 90 daysafter planting (DAP). Thistreatment along with postemergence application of glyphosate (1.0 kg a.i./ha at 90 DAP) gave best results at 180 DAP. The corm and cormel production was significantly higher in oxyfluorfen treatment. The results indicate that application of oxyfluorfen as pre-emergence herbicide followed by application of glyphosate at 90 DAP could be an effective treatment for weed control in gladiolus cormels. r 2005 Published by Elsevier Ltd
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