1,403 research outputs found

    Position determination of a lander and rover at Mars with Earth-based differential tracking

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    The presence of two or more landed or orbiting spacecraft at a planet provides the opportunity to perform extremely accurate Earth-based navigation by simultaneously acquiring Doppler data and either Same-Beam Interferometry (SBI) or ranging data. Covariance analyses were performed to investigate the accuracy with which lander and rover positions on the surface of Mars can be determined. Simultaneous acquisition of Doppler and ranging data from a lander and rover over two or more days enables determination of all components of their relative position to under 20 m. Acquiring one hour of Doppler and SBI enables three dimensional lander-rover relative position determination to better than 5 m. Twelve hours of Doppler and either SBI or ranging from a lander and a low circular or half synchronous circular Mars orbiter makes possible lander absolute position determination to tens of meters

    Linkage Between Effective Implementation of IS Strategy and IS Performance: Lessons from Indian Organizations

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    The overall outcome of IS planning efforts is determined by how effectively the planned strategies are implemented in order to realize the envisaged strategic benefits. This empirical work on IS plan implementation relates the effective implementation of IS plan with IS performance in the Indian context. Based on three case studies from diverse industry segments, we discuss the five important parameters of IS plan implementation- top management commitment, implementation responsibility, IS plan characteristics, user involvement, role of IS function that determine the implementation effectiveness and eventually the IS performance. Based on the analysis, we present a set of key learnings for developing countries, along with implications for future research

    Some derivations among Logarithmic Space Bounded Counting Classes

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    In this paper we show derivations among logarithmic space bounded counting classes based on closure properties of #L\#L that leads us to the result that NL=C=LPLNL=C_=L\subseteq PL.Comment: 3 page

    Effect of calorie supplementation on growth of undernourished children

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    The results reported here may be generally applicable to poor communities in several Asian countries where dietaries are based largely on cereals and to a smaller extent on legumes and pulses. They may perhaps not be applicable to situations in some African countries where the staples are tapioca and plantain. The present observations should not be interpreted to mean that the current home diets in the concerned poor communities are satisfactory and do not need improvement. On the contrary, these diets are deficient in a number of nutrients, particularly vitamin A, riboflavin, iron, and possibly calcium. It should, however, be possible to overcome some of these deficiencies by improving the existing dietaries through the inclusion of relatively inexpensive foods that are locally available and well within the reach of the poor. A question often raised is whether, in view of the bulk arising from low fat content and low calorie concentration, young children would be able to consume predominantly cereal-based diets in quantities adequate to meet their calorie needs. The present study shows that the bulk should not present an insuperable problem provided the total daily diet is divided into several appropriate meals in the course of the day. The immediate practical approach towards combating malnutrition in children living in poor rural Asian communities would seem to lie in educating these communities in bridging the calorie gap with the present dietaries after such improvement, rather than in distributing elaborately processed "protein-rich formulations," which are unnecessary and expensive

    Morphophysiological characters of Dendrobium var. Yellow Splash as influenced by bioinoculants and different levels of benzyladenine

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    Dendrobium is the most commonly grown tropical orchid species in India and Kerala. They are highly specific about their nutrient requirement. The use of bio-inoculants in crop production of ornamentals has opened up a new possibility of using them for improving the growth and yield of orchids. Hence the objective of study was to evaluate the response of Dendrobium cv. Yellow Splash to different kinds of bio-inoculants viz., AMF, Azospirillum and a microbial consortia PGPR Mix – 1 developed from KAU, along with 50, 100 and 150 ppm of benzyladenine. The experiment consisted of ten different treatments involving bio-inoculants and benzyladenine. Plant height and number of leaves were maximum in the plants inoculated with AMF along with 100 ppm benzyladenine. Treatment comprising of Azospirillum and 100 ppm benzyladenine was superior in terms of other morphological parameters like leaf breadth, leaf area and plant spread. Maximum leaf length and highest number of shoots were observed in plants inoculated with Azospirillumand 150 ppm benzyladenine. Considering the floral parameters, both quantitative and qualitative attributes were found to be superior in the treatment consisting of AMF along with 150 ppm benzyladenine. Highest root length was observed under the treatment AMF along with 100 ppm benzyladenine while number of roots and root volume were maximum in the plants inoculated with Azospirillum and 150 ppm benzyladenine. Plants inoculated with AMF and 100 ppm benzyladenine had highest chlorophyll content while highest stomatal frequency was observed under the treatment Azospirillum and 100 ppm BA. From the study it could be concluded that inoculation of Dendrobium orchids with bio-inoculants like AMF and Azospirillum can significantly improve the morphological characters of the plants which in turn influence the production of quality spikes

    Haematological and Biochemical Changes in Response to Stress Induced by the Administration of Amikacin Injection by Autoinjector in Animals

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    The drugs administered by autoinjectors, may act fast reducing the morbidity and mortality in critical and emergency situations. Amikacin drug cartridge was developed for the autoinjector as an antibacterial drug for critical situations and its tolerability was studied. Rats were given either 3 doses or 7 doses on consecutive days by the autoinjector (intraperitoneal, 63 mg/mL). Blood was withdrawn on the 4th day (3 doses) or the 8th day (7 doses), and haematological and biochemical parameters were studied. All the parameters studied were within the limits and did not show any significant difference when compared with the control. Rabbits were given 3 doses of two concentrations (intramuscular, 63 or 250 mg/mL) and on the 4th day blood was withdrawn for the haematological and biochemical estimations. 63 mg/mL cartridge did not show any significant change while 250 mg/mL cartridge showed significant change in the haematological and biochemical parameters. This study showed that intraperitoneal injection of amikacin by the autoinjector designed for intramuscular injection was well tolerated by the rats. In the rabbits, low dose (63 mg/mL) was tolerated while the higher dose, which is an adult human dose (250 mg/mL) showed significant changes.Defence Science Journal, 2014, 64(2), pp. 99-105. DOI: http://dx.doi.org/10.14429/dsj.64.503

    Protective Effect of Quercetin Against Sulphur Mustard-inducedOxidative Stress in Mice

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    Sulphur mustard (SM) is a chemical warfare agent that causes serious blisters upon contactwith human skin.  SM alkylates DNA and several other macromolecules, and also induces oxidativestress.  Quercetin, a bioflavonoid has wide pharmacological actions. The protective efficacy ofquercetin (100 mg/kg, i.p. and 200 mg/kg, i.p.) was studied by administering three doses in miceagainst SM.  The first dose was administered at 30 min prior, simultaneous, 2 h post or 24 h post,and two more doses on the next two days.  SM was administered (in PEG 300) percutaneouslyat varying doses for survival and protection studies.  SM was also administered at a dose of2 LD50 (19.3 mg/kg) with and without quercetin treatment and various biochemical markers wereestimated 7 days after SM administration.  Histological examinations of vital organs were alsocarried out. The animals administered with SM died at various days depending upon the dose.The body weight decreased significantly. Quercetin protected the mice significantly, in a dose-dependent manner. The protection was better when the first dose of quercetin administered was30 min prior or simultaneously.  A significant decrease in reduced as well as oxidised glutathioneand an increase in malondialdehyde, WBC count, RBC count, and haemoglobin were observedwith 2 LD50 SM. Quercetin at 100 mg/kg and 200 mg/kg doses significantly protected the biochemicalmarkers when the first dose of quercetin administered was 30 min prior or as simultaneoustreatment.  The histological lesions induced by sulphur mustard on liver, spleen, and skin werealso significantly protected by quercetin when the first dose was administered 30 min prior oras simultaneous treatment. The present study shows that percutaneous administration of SMinduces oxidative stress and quercetin can protect it as a prophylactic agent

    Dielectrophoretic assembly of high-density arrays of individual graphene devices for rapid screening

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    We establish the use of dielectrophoresis for the directed parallel assembly of individual flakes and nanoribbons of few-layer graphene into electronic devices. This is a bottom-up approach where source and drain electrodes are prefabricated and the flakes are deposited from a solution using an alternating electric field applied between the electrodes. These devices are characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and electron transport measurements. They are electrically active and their current carrying capacity and subsequent failure mechanism is revealed. Akin to carbon nanotubes, we show that the dielectrophoretic deposition is self-limiting to one flake per device and is scalable to ultralarge-scale integration densities, thereby enabling the rapid screening of a large number of devices

    Biochemical changes and energy utilisation in developing stages of the estuarine prawn, Macrobrachium idella (Hilgendrof)

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    Changes in the biochemical composition, caloric content and energy utilisation during the embryonic stages of Macrobrachium idella were studied. The results show that protein contributes to about 67.4% of the total energy available for development. The gross efficiency of the prawn works out to be 44.0%

    Specific Soluble Oligomers of Amyloid-β Peptide Undergo Replication and Form Non-Fibrillar Aggregates in Interfacial Environments

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    Aggregates of amyloid-β (Aβ) peptides have been implicated in the etiology of Alzheimer disease. Among the different forms of Aβ aggregates, low molecular weight species ranging between ∼2- and 50-mers, also called “soluble oligomers,” have emerged as the species responsible for early synaptic dysfunction and neuronal loss. Emerging evidence suggests that the neurotoxic oligomers need not be formed along the obligatory nucleation-dependant fibril formation pathway. In our earlier work, we reported the isolation of one such “off-pathway” 12–18-mer species of Aβ42 generated from fatty acids called large fatty acid-derived oligomers (LFAOs) (Kumar, A., Bullard, R. L., Patel, P., Paslay, L. C., Singh, D., Bienkiewicz, E. A., Morgan, S. E., and Rangachari, V. (2011) PLoS One 6, e18759). Here, we report the physiochemical aspects of LFAO-monomer interactions as well as LFAO-LFAO associations in the presence of interfaces. We discovered that LFAOs are a replicating strain of oligomers that recruit Aβ42 monomers and quantitatively convert them into LFAO assemblies at the expense of fibrils, a mechanism similar to prion propagation. We also found that in the presence of hexane-buffer or chloroform-buffer interfaces LFAOs are able to associate with themselves to form larger but non-fibrillar aggregates. These results further support the hypothesis that low molecular weight oligomers can be generated via non-fibril formation pathways. Furthermore, the unique replicating property of off-pathway oligomers may hold profound significance for Alzheimer disease pathology
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