Performance of disc brushless DC motor applied as gearless drive for wheelchair

The currently used electric drive for a wheelchair consists of brush permanent magnet DC motor and mechanical transmission that drives the wheels. The overall efficiency of this kind of drive usually does not exceed 60%. At present there is under study much more effective drive that consists of brushless DC motor which embedded into the wheel rim directly drives the wheelchair. This type of high efficiency gearless drive is the object of this thesis project. The particular brushless DC motor is a torus - type motor with a high energy rare - earth magnets and ferromagnetic teeth that fill in the space between the coils of Gramme\u27s winding. The objectives of the project were to determine by computer simulation and laboratory test the electromechanical characteristics of the motor prototype in steady - state and dynamic conditions. For this purpose the measurement stand has been built and measurements were carried out in variable load conditions. To analyze the motor characteristics theoretically the mathematical models of the motor were developed one for steady - state and one for dynamic operation. The simulation of the motor drive was done using MATLAB/ SIMULINK software package. The results obtained from simulation confirm the requirements put on the gearless wheelchair drive and the determined motor ratings are as follows: supply voltage - 24 V, input current - 8.7 A, torque - 9.7 Nm, speed - 161 rpm, efficiency, 78 %. The cogging torque is practically unnoticeable. The results obtained from the test practically do not differ from those obtained from simulation. It means the calculation model used in simulation of steady - state and dynamic conditions has been verified positively

Neuromodulation of intrinsic and synaptic plasticity in auditory cortex

The study of auditory system development and plasticity is important. Large populations of people suffer from hearing loss throughout their lifetime. To optimize treatment for children with hearing loss, it is crucial to understand how early hearing loss affects the development and processing of the central auditory system. Equally important is the understanding of how changes in neural activity in the auditory pathways can have an effect on its function. In this thesis, I studied 1) how hearing loss affects auditory cortical activity and 2) the mechanisms that could underlie learning and memory of sound information. In the first study, I found that hearing loss enhances auditory cortical activity and alters the manner in which the auditory cortex responds to the neuromodulator serotonin. In the second study, I found that the auditory cortex follows unique cellular learning and memory rules and these rules are altered by the neuromodulator acetylcholine

STANDARDIZATION OF YOGAAMRUTO RASA BY USING MODERN ANALYSIS TECHNIQUES

Rasa Shastra is a partially independent branch of Ayurvedic medicine, which deals with preparation of the drugs with metals and minerals to produce the drugs with higher efficacy in lower dose with good palatability. Yogaamruto Rasa (YMR) is one such Rasoushadhi mentioned in Rasa Kamdhenu indicated for all types of Kushta. Parada, Gandhaka, Tamra churna, Vatsanabha, Vacha, Trikatu, Musta and Vidanga are the main ingredients of YMR. Shodhana, Mardana, Murchchana, Pishti nirmana, Aagni paaka are the important steps involved in preparation of YMR. Till date no standards are available for the above drug. Need of the hour is to revalidate the safety and efficacy of the above said formulation. In the current study of YMR it was subjected to analysis through X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDX) and Zeta potential (ZP). XRD of YMR reveals that major peaks are of Cu20 (Cuprite) and minor peaks of HgS (Meta Cinnabar), Cu2S (Cuprous Sulphide). SEM study found the smallest grain size ranging between115nm at 5Kx magnification to 82.11 nm at 7Kx magnification. EDX study reveals that YMR contains significant percentage of O-25.96%, Cu-22.82%, C-20.41%, Hg- 12.84 %, S- 9.8%. w/w. ZP mean value for YMR is 51.4 mV which indicates moderate colloidal stability.

Engineering of Deinococcus radiodurans R1 for bioprecipitation of uranium from dilute nuclear waste

Genetic engineering of radiation-resistant organisms to recover radionuclides/heavy metals from radioactive wastes is an attractive proposition. We have constructed a Deinococcus radiodurans strain harboring phoN, a gene encoding a nonspecific acid phosphatase, obtained from a local isolate of Salmonella enterica serovar Typhi. The recombinant strain expressed an ~27-kDa active PhoN protein and efficiently precipitated over 90% of the uranium from a 0.8 mM uranyl nitrate solution in 6 h. The engineered strain retained uranium bioprecipitation ability even after exposure to 6 kGy of 60Co gamma rays. The PhoN-expressing D. radiodurans offers an effective and eco-friendly in situ approach to biorecovery of uranium from dilute nuclear waste

Transgenic brain-derived neurotrophic factor expression causes both anxiogenic and antidepressant effects

Although neurotrophins have been postulated to have antidepressant properties, their effect on anxiety is not clear. We find that transgenic overexpression of the neurotrophin BDNF has an unexpected facilitatory effect on anxiety-like behavior, concomitant with increased spinogenesis in the basolateral amygdala. Moreover, anxiogenesis and amygdalar spinogenesis are also triggered by chronic stress in control mice but are occluded by BDNF overexpression, thereby suggesting a role for BDNF signaling in stress-induced plasticity in the amygdala. BDNF overexpression also causes antidepressant effects, because transgenic mice exhibit improved performance on the Porsolt forced-swim test and an absence of chronic stress-induced hippocampal atrophy. Thus, structural changes in the amygdala and hippocampus, caused by genetic manipulation of the same molecule BDNF, give rise to contrasting effects on anxiety and depressive symptoms, both of which are major behavioral correlates of stress disorders

Detection of seedborne grain mold fungi in sorghum and their control with fungicidal seed treatment

Seeds of mould resistant sorghum cultivars IS 8545 and PVK 801, as well as those of the susceptible cultivars Bulk Y, SPV 104 and CSH 9 were used to investigate the nature of the seedborne nature of the predominant mould fungi infecting sorghum. Alongside this, the efficacy of thiram and Bavistin [carbendazim] SD and ST in controlling seed mould fungi was determined. Infection of seed coat, endosperm and embryo of sorghum was due to Fusarium verticillioides and Curvularia lunata [Cochliobolus lunatus]. Infection of plant tissues was lower in resistant than susceptible cultivars. Infection by C. lunata and F. verticillioides ranged from 20 to 84% and from 12 to 74%, respectively. All the fungicide treatments reduced the grain colonization by mould fungi in cultivars Bulk Y, SPV 104, IS 8545 and PKV 801 compared to the control. Seed treatment with thiram reduced seed infection by C. lunata, whereas seed treatment with bavistin reduced seed infection by F. verticillioides. Reduction in grain mould infection resulted in a 4 to 47% increase in grain yield

A novel tissue-specific meta-analysis approach for gene expression predictions, initiated with a mammalian gene expression testis database

<p>Abstract</p> <p>Background</p> <p>In the recent years, there has been a rise in gene expression profiling reports. Unfortunately, it has not been possible to make maximum use of available gene expression data. Many databases and programs can be used to derive the possible expression patterns of mammalian genes, based on existing data. However, these available resources have limitations. For example, it is not possible to obtain a list of genes that are expressed in certain conditions. To overcome such limitations, we have taken up a new strategy to predict gene expression patterns using available information, for one tissue at a time.</p> <p>Results</p> <p>The first step of this approach involved manual collection of maximum data derived from large-scale (genome-wide) gene expression studies, pertaining to mammalian testis. These data have been compiled into a Mammalian Gene Expression Testis-database (MGEx-Tdb). This process resulted in a richer collection of gene expression data compared to other databases/resources, for multiple testicular conditions. The gene-lists collected this way in turn were exploited to derive a 'consensus' expression status for each gene, across studies. The expression information obtained from the newly developed database mostly agreed with results from multiple small-scale studies on selected genes. A comparative analysis showed that MGEx-Tdb can retrieve the gene expression information more efficiently than other commonly used databases. It has the ability to provide a clear expression status (transcribed or dormant) for most genes, in the testis tissue, under several specific physiological/experimental conditions and/or cell-types.</p> <p>Conclusions</p> <p>Manual compilation of gene expression data, which can be a painstaking process, followed by a consensus expression status determination for specific locations and conditions, can be a reliable way of making use of the existing data to predict gene expression patterns. MGEx-Tdb provides expression information for 14 different combinations of specific locations and conditions in humans (25,158 genes), 79 in mice (22,919 genes) and 23 in rats (14,108 genes). It is also the first system that can predict expression of genes with a 'reliability-score', which is calculated based on the extent of agreements and contradictions across gene-sets/studies. This new platform is publicly available at the following web address: <url>http://resource.ibab.ac.in/MGEx-Tdb/</url></p

Design and Synthesis of Different Aryl Substituted 1,3,4-Oxadiazole-imidazo[1,5-a]pyridine Derivatives as Anticancer Agents

A new series of 1,3,4-oxadiazole incorporated imidazo[1,5-a]pyridine derivatives was prepared. Anticancer activity of all the obtained compounds was investigated by employing MTT assay. Among them, six compounds showed most prominent anticancer activity than etoposide

STDP in the Developing Sensory Neocortex

Spike timing-dependent plasticity (STDP) has been proposed as a mechanism for optimizing the tuning of neurons to sensory inputs, a process that underlies the formation of receptive field properties and associative memories. The properties of STDP must adjust during development to enable neurons to optimally tune their selectivity for environmental stimuli, but these changes are poorly understood. Here we review the properties of STDP and how these may change during development in primary sensory cortical layers 2/3 and 4, initial sites for intracortical processing. We provide a primer discussing postnatal developmental changes in synaptic proteins and neuromodulators that are thought to influence STDP induction and expression. We propose that STDP is shaped by, but also modifies, synapses to produce refinements in neuronal responses to sensory inputs

Climate resilience of dry season cereals in India

India is the world’s second largest producer of wheat, with more than 40% increase in production since 2000. Increasing temperatures raise concerns about wheat’s sensitivity to heat. Traditionally-grown sorghum is an alternative rabi (winter season) cereal, but area under sorghum production has declined more than 20% since 2000. We examine sensitivity of wheat and sorghum yields to historical temperature and compare water requirements in districts where both cereals are cultivated. Wheat yields are sensitive to increases in maximum daily temperature in multiple stages of the growing season, while sorghum does not display the same sensitivity. Crop water requirements (mm) are 1.4 times greater for wheat than sorghum, mainly due to extension of its growing season into summer. However, water footprints (m3 per ton) are approximately 15% less for wheat due to its higher yields. Sensitivity to future climate projections, without changes in management, suggests 5% decline in wheat yields and 12% increase in water footprints by 2040, compared with 4% increase in water footprint for sorghum. On balance, sorghum provides a climate-resilient alternative to wheat for expansion in rabi cereals. However, yields need to increase to make sorghum competitive for farmer profits and efficient use of land to provide nutrients