390 research outputs found

    Multisite Microprobes for Electrochemical Recordings in Biological Dynamics

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    For over 30 years, techniques have been developed that allow for the microscale (10-30 /mum) measurement of chemical signals with high temporal resolution (1-200 Hz). Such measurements, called in vivo electrochemical recordings, allow for the direct determination of neurotransmitter molecules and related compounds in biological systems. Multiple recordings, simultaneously performed at different, closely spaced, well defined locations throughout a three-dimensional tissue volume in the brain, are of interest in neuroscience. Developments in microelectronic techniques enable the fabrication of multi-electrode microprobes for recording extracellular action potentials generated by individual neurons simultaneously. A high-yield microfabrication process has been successfully developed for the fabrication of a novel semiconductor based, four-site silicon microprobe that involves a three-mask process and standard UV photolithography. A plasma process has been developed for dry etching of the gold electrodes and conducting lines. The electrochemical behavior of the microprobe is investigated by a high-speed computer-based in vitro electrochemical recording system. The electrochemical signals are measured at 5 Hz and varying gain. It is found that a selectivity of over 500:1 is achieved, and the signal to noise ratio of the recorded signal is particularly suitable for in vivo recordings

    Prediction of storability of organically produced paddy seeds through natural and accelerated ageing techniques

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    The present study was conducted to know the storage potential of organically produced paddy seeds in the Department of Seed Science and Technology, University of Agricultural Sciences, Raichur. The seed lot were divided into two parts, one part was stored in cloth bag for a period of 12 months under ambient conditions. At thesame time another set of seeds were subjected to accelerated ageing at 42 + 10C temperature and 90 per cent relative humidity (RH) for a period of 0-12 days. Among the ageing methods, artificially aged seeds showed drastic decreases in seed quality as compared to natural ageing. Among the treatments T9 (37.5 % FYM + 37.5 % vermicompost + 25 % neem cake + foliar spray of panchagavya on 30, 60, 90 and 120 DAT) recorded significantly highest seed quality parameters viz., seed germination (97.81 %), seedling length (29.42 cm) and SVI (2878) at initial stage in both the method of aging and at the end of storage period; seed germination (71.23 and 87.33 %), seedling length (19.66 and 27.00 cm) and SVI (1400 and 2358) in accelerated ageing (AA) and natural ageing (NA) respectively, whereas, lowest in control (Inorganic treatment). The seed quality parameters of four days of AA were similar to that of six months of NA. Hence, storability of organically produced paddy seeds were better as compared to inorganic seeds and it can be predicted that four days of AA is equal to six months of NA. The information generated will be useful in retention or disposal of a particular variety or seed lot

    Multisite Microprobes for Electrochemical Recordings in Biological Dynamics

    Get PDF
    For over 30 years, techniques have been developed that allow for the microscale (10-30 /mum) measurement of chemical signals with high temporal resolution (1-200 Hz). Such measurements, called in vivo electrochemical recordings, allow for the direct determination of neurotransmitter molecules and related compounds in biological systems. Multiple recordings, simultaneously performed at different, closely spaced, well defined locations throughout a three-dimensional tissue volume in the brain, are of interest in neuroscience. Developments in microelectronic techniques enable the fabrication of multi-electrode microprobes for recording extracellular action potentials generated by individual neurons simultaneously. A high-yield microfabrication process has been successfully developed for the fabrication of a novel semiconductor based, four-site silicon microprobe that involves a three-mask process and standard UV photolithography. A plasma process has been developed for dry etching of the gold electrodes and conducting lines. The electrochemical behavior of the microprobe is investigated by a high-speed computer-based in vitro electrochemical recording system. The electrochemical signals are measured at 5 Hz and varying gain. It is found that a selectivity of over 500:1 is achieved, and the signal to noise ratio of the recorded signal is particularly suitable for in vivo recordings

    Study of acute phase reactants in children with sepsis, with special reference to C-reactive protein and procalcitonin

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    Background: Several inflammatory markers have failed to meet the requirements for an early diagnosis of sepsis in children. Studyresults and trends show that measurement of the combination of biochemical markers offers the best prospects for research on earlydiagnosis of sepsis. Objectives: To evaluate the serum levels of C-reactive protein (CRP) and procalcitonin (PCT) as markers of earlysepsis in pediatric patients. Methods: All the hospitalized children aged more than 28 days with clinically suspected sepsis, as per thedefinition given by International Pediatric Sepsis Consensus Conference, were selected. The patients were divided into two groups; onewith culture proven sepsis and the other with culture negative sepsis. CRP and PCT levels were measured at the time of admission and48 h after admission. Results: A 40 patients were studied, out of that 15 had culture positive and 25 had culture negative sepsis. Themean PCT level was significantly higher at admission than at 48 h after admission, and the mean CRP level was significantly lower atadmission than at 48 h after admission indicating PCT as early marker of sepsis. Conclusion: CRP and PCT levels have favorable testperformance in differentiating between culture positive and culture negative sepsis. PCT is earlier to rise compared to CRP and PCT isbest in predicting the severity followed by CRP

    Universal behaviour of entrainment due to coherent structures in turbulent shear flow

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    I suggest a solution to a persistent mystery in the physics of turbulent shear flows: cumulus clouds rise to towering heights, practically without entraining the ambient medium, while apparently similar turbulent jets in general lose their identity within a small distance through entrainment and mixing. From dynamical systems computations on a model chaotic vortical flow, I show that entrainment and mixing due to coherent structures depend sensitively on the relative speeds of different portions of the flow. A small change in these speeds, effected for example by heating, drastically alters the sizes of the KAM tori and the chaotic mixing region. The entrainment rate and, hence, the lifetime of a turbulent shear flow, shows a universal, non-monotone dependence on the heating.Comment: Preprint replaced in order to add the following comment: accepted for publication in Phys. Rev. Let

    Porting Decision Tree Algorithms to Multicore using FastFlow

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    The whole computer hardware industry embraced multicores. For these machines, the extreme optimisation of sequential algorithms is no longer sufficient to squeeze the real machine power, which can be only exploited via thread-level parallelism. Decision tree algorithms exhibit natural concurrency that makes them suitable to be parallelised. This paper presents an approach for easy-yet-efficient porting of an implementation of the C4.5 algorithm on multicores. The parallel porting requires minimal changes to the original sequential code, and it is able to exploit up to 7X speedup on an Intel dual-quad core machine.Comment: 18 pages + cove

    Use of Xpert MTB/RIF in Decentralized Public Health Settings and Its Effect on Pulmonary TB and DR-TB Case Finding in India

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    Background Xpert MTB/RIF, the first automated molecular test for tuberculosis, is transforming the diagnostic landscape in high-burden settings. This study assessed the impact of up-front Xpert MTB/RIF testing on detection of pulmonary tuberculosis (PTB) and rifampicin-resistant PTB (DR-TB) cases in India. Methods This demonstration study was implemented in 18 sub-district level TB programme units (TUs) in India in diverse geographic and demographic settings covering a population of 8.8 million. A baseline phase in 14 TUs captured programmatic baseline data, and an intervention phase in 18 TUs had Xpert MTB/RIF offered to all presumptive TB patients. We estimated changes in detection of TB and DR-TB, the former using binomial regression models to adjust for clustering and covariates. Results In the 14 study TUs, which participated in both phases, 10,675 and 70,556 presumptive TB patients were enrolled in the baseline and intervention phase, respectively, and 1,532 (14.4%) and 14,299 (20.3%) bacteriologically confirmed PTB cases were detected. The implementation of Xpert MTB/RIF was associated with increases in both notification rates of bacteriologically confirmed TB cases (adjusted incidence rate ratio [aIRR] 1.39; CI 1.18-1.64), and proportion of bacteriological confirmed TB cases among presumptive TB cases (adjusted risk ratio (aRR) 1.33; CI 1.6-1.52). Compared with the baseline strategy of selective drug-susceptibility testing only for PTB cases at high risk of drug-resistant TB, Xpert MTB/RIF implementation increased rifampicin resistant TB case detection by over fivefold. Among, 2765 rifampicin resistance cases detected, 1055 were retested with conventional drug susceptibility testing (DST). Positive predictive value (PPV) of rifampicin resistance detected by Xpert MTB/RIF was 94.7% (CI 91.3-98.1), in comparison to conventional DST. Conclusion Introduction of Xpert MTB/RIF as initial diagnostic test for TB in public health facilities significantly increased case-notification rates of all bacteriologically confirmed TB by 39% and rifampicin-resistant TB case notification by fivefold

    Next-generation modelling approaches for sustainable crop protection

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    The combined pre and post-harvest insect-pest and disease infestation causes an annual estimated 40-50% of total produce loss. Overall loss of attainable yield is more severe in the Asian and African continents because of transboundary insect pests, inconsistent access to crop protection products and lack of preparedness. Solicit innovative, digitally enabled lowcost climate smart pest management technologies for real-time pest forecasting and decision support systems (DSSs) are of great significance and inevitable. Considering this, efforts have been made to develop weather based forewarning models for pests in Chickpea and Pigeonpea (Helicoverpa, Phytophthora blight) and Cotton (Aphid, Leaf hopper, thrips, whitefly) for forewarning time of first appearance of pest, maximum severity/pest population vis-à-vis’ crop age. Using weather indices, models were obtained through stepwise regression technique and machine learning (artificial neural network and Bayesian network) techniques. In general, the models fitted well for all the available data and have good agreement between forecasts and observed status. The predictive ability and accuracy of models will be further validated through cross-location and cross-year models. Further, development of Hybrid Mobile App with Microsoft Azure and promoting e/m-participation will help in dissemination of information to end users for real-time pest monitoring, prediction and crop protection advisory
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