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Orbiting objects in space are exposed to the risk of collision with space debris over their lifetime. Space debris orbiting in space experiences orbital decay due to various orbital perturbations. This work considers only orbital perturbations due to aerodynamic forces, which spacecraft experience due to the presence of a rarefied atmosphere, causing tumbling motion and orbital decay. Analysis of the orbital decay of a spacecraft is carried out by considering the variation of the drag coefficient as a function of its shape, motion and angle-of-attack. An in-house Direct Simulation Monte Carlo (DSMC) solver is modified for aerodynamic analysis of a spacecraft orbiting in the free molecular regime in low Earth orbit. In addition, an orbital dynamics model is developed to simulate the tumbling motion of a spacecraft and its orbital decay. The orbital decay trajectory is predicted for two sample spacecrafts using the aerodynamic coefficients obtained from the in-house DSMC solver as inputs to the orbital decay model. This study analyses and explores in detail the effects of the aerodynamic coefficients and shape of a spacecraft on its orbital decay.
Jackfruit (Artocarpus heterophyllus Lam.) is a nutritious crop from the Moraceae family. The current study was undertaken to evaluate the phenotypic diversity of fruit characteristics using a set of 27 standardized fruit descriptors to describe 28 jackfruit genotypes. These data were used to identify the superior jackfruit genotype that could be used for commercial cultivation. The data revealed a wide range of differences among the genotypes for all the traits studied. Cluster analysis classified the genotypes into four major groups that confirmed the wide diversity among them. Principal component analysis (PCA) also revealed that 80.22% of the variability among the jackfruit genotypes was explained by the first five principal components (PCs). Based on the overall results, the Indian Council of Agricultural Research, Research Complex for Eastern Region (ICAR-RCER) JS 6/3 and 10/3 genotypes were found to be the most promising for table purposes (medium fruit size, pulp percentage >50 and total soluble solid (TSS) >20°Brix), whereas the ICAR-RCER JS 7/7 genotype with large fruit size, pulp percentage >50 and TSS >20°Brix was found to be suitable for processing. The coefficient of variation was the least for traits such as TSS (12.56%) and average seed length (13.56%). Hence, priority may also be given to the TSS and seed size when exploring promising genotypes and operating a selection procedure for crop improvement in jackfruit. The information generated under the study forms a potential baseline for fruit breeders to use in selecting genotypes with superior fruit qualities for jackfruit crop improvement programmes in the future.
Taenia solium cysticercosis is a major public health problem in developing countries. Swine cysticercosis results in economic losses for pig farmers in disease endemic areas. Consumption of cysticercotic pork leads to taeniasis in humans. Eggs excreted in the faeces of T. solium carriers disseminate to humans and pigs through the faecal–oral route, thus maintaining the life cycle in endemic areas. An enzyme-linked immunoelectrotransfer blot (EITB) assay was developed using whole crude T. solium cysticercus antigens (WCA) for the diagnosis of swine cysticercosis. Sera from 30 swine with cysticercosis confirmed by magnetic resonance imaging were subjected to EITB assay. Sera from 50 swine that were raised in a government farm and not allowed to roam freely were included as negative controls. Two or more bands of 8, 11, 14, 24, 26 and 29 kDa were immunoreactive on blot with sera from all infected swine except two, and none from swine raised on the government farm. The overall sensitivity and specificity of EITB assay for diagnosis of swine cysticercosis were 93.3% and 100%, respectively. Hence, EITB assay based on WCA may be a suitable diagnostic tool for swine cysticercosis in endemic areas.
The acceleration of an electron by the ponderomotive force of a Gaussian whistler pulse in a magnetized high-density quantum plasma obeying Fermi–Dirac distribution is studied using the recently developed quantum hydrodynamic model. Effective acceleration takes place when the peak whistler amplitude exceeds a threshold value, and the whistler frequency is greater than the cyclotron frequency. The threshold amplitude decreases with ratio of plasma frequency to electron cyclotron frequency. The electron is accelerated at velocities of about twice the group velocity of the whistler.
Laser-produced copper plasma in the presence of variable transverse external magnetic field in air is investigated using optical emission spectroscopy. As the magnetic field increases from 0 to 0.5 T, the intensity of Cu I lines initially increases and then decreases slightly at a 0.5 T. The maximum intensity enhancement of all five Cu I lines occurs at a magnetic field of 0.3 T. The increase in intensity is attributed to an increase in the electron impact excitation of Cu. With increase in magnetic field, the electron density and temperature were found to increase due to increase in the confinement of plasma. The difference in intensity enhancement factor is due to the difference in excitation rate coefficients. The surface morphology of irradiated copper target is also analyzed at 0.3 T magnetic field at which the density is maximum and reveals the formation of Cu/Cu2O/CuO nanoparticles (NPs). More NPs are formed at the peripheral region than at the central region of the ablated crater and is due to the oxidation of Cu atom in the plasma–ambient interface. The larger grain size of nanostructures in the presence of magnetic field is due to an increase in the inverse pulsed laser deposition. The intensity of Raman peak of Cu2O decreases in the presence of magnetic field and that of CuO increases which is more likely due to conversion of Cu2O to CuO. The photoluminescence intensity of CuO increases in the presence of magnetic field due to the phase transformation of Cu2O to CuO in agreement with the result of Raman spectroscopy.
The possibilities of electron acceleration by ponderomotive force of a circularly polarized laser pulse in magnetized quantum plasma have been explored. The basic mechanism involves acceleration of electron by the axial gradient in the ponderomotive potential of the laser. The quantum effects have been taken into account for a high-density plasma. The ponderomotive force of the laser is resonantly enhanced when Doppler up-shifted laser frequency equals the cyclotron frequency.
Copper nanoparticles are synthesized successfully through chemical reduction of different copper salts stabilized by Ocimum Sanctum Leaf extract, a natural biopolymer. The resulting copper nanoparticles are characterized by using UV Visible Absorption Spectrometer, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Small Angle X-ray Scattering (SAXS) and Fourier Transform Infrared Spectroscopy (FTIR) experiments. Copper nanoparticles prepared display an absorption peak at around 558 nm. X-ray diffraction analysis shows that the particles are FCC crystalline. SEM and TEM display the formation of copper nanoparticles with an average size of 10 nm. The SAXS studies demonstrate the formation of spherical nanoparticles with bimodal size distribution. The FTIR spectrum analysis has confirmed the presence of functional groups of stabilizer Ocimum Sanctum leaf extract in capping the copper nanoparticles.
Sharp-tail sunfish (Masturus lanceolatus) occurrence in Indian seas is uncommon and its taxonomy is still in controversy. The species was hooked in a sub-surface long-line during an exploratory survey for oceanic tuna and allied fish within the Indian exclusive economic zone in the Lakshadweep Sea along the west coast of India by survey ship MFV ‘Yellow Fin’ attached to the Fishery Survey of India, Mormugoa, Goa, India. It is reported to be the first Masturus species in the Lakshadweep Sea. The sample weighted 100 kg and had a total length of 147 cm. The morphometric and meristic measurements were made and results indicated; the species recorded was the third largest in total length and the heaviest in terms of mass compared to earlier reports in Indian seas.
Enterobius vermicularis infection remains one of the most common parasitic infections, particularly prevalent in children. Enterobiasis, although not usually dangerous, may cause significant morbidity. Elimination of the parasite from a family or an institution often poses problems, either because of an incomplete cure or re-infection. While there have been limited reports of ectopic enterobiasis throughout the world, ours is probably one of the rarest reports of recurrent vaginal E. vermicularis infection in the absence of any gastrointestinal symptoms despite complete treatment. A 4-year-old girl presented with recurrent episodes of vulval itching on 3–4 occasions over 2 years. There was no pruritis ani nor urinary/gastrointestinal complaints. The vulva was inflamed with 4–5 living worms, 6–7 mm in length, emerging from the anterior vaginal fornix, but with no vaginal discharge. Direct microscopic examination of vaginal swabs revealed adult worms of Enterobius but no eggs. Repeated stool samples from the patient, parents and a sibling were negative. The patient was treated orally with 100 mg of mebendazole for 3 days followed by two more courses at 3-week intervals over a period of 3 months. Recurrent vaginal enterobiasis despite complete treatment and in the absence of any gastrointestinal involvement suggests that the vagina is a potential reservoir for E. vermicularis, which supports the theory of rare ectopic enterobiasis through the ascending pathway of the female genital tract.
In this study a new species of nematode, Iheringascaris goai n. sp., is reported from two fish hosts, including silver whiting, Sillago sihama, and spotted catfish, Arius maculatus, caught off the Central West Coast of India at Goa. The new species can be differentiated morphologically from I. inquies, the most closely related species collected from cohabiting marine fish. The distinguishing characteristics are distinct cuticular striations, a unilateral excretory system, the presence of dentigerous ridges on the inner margin of the lips and the ratio of oesophagus to body length. In males, the ratio of spicules to body length is higher and the number of pre-anal papillae is less in comparison to those in I. inquies. In addition, the tail curves ventrad in males, while in females, the vulva is post-equatorial. The sequence alignment of 18S rDNA and cytochrome c oxidase subunit I with sequences of known species selected from the same superfamily shows a significant difference. The morphological and molecular differences reported here can, therefore, be used to assign the specimen to a new species.
The present study describes the activity of a nanomaterial on protoscoleces of Echinococcus granulosus, which exhibited morphological changes and apoptosis. Apoptotic changes were deduced on the basis of effector caspase activation and nucleosomal laddering. Invaginated protoscoleces maintained in vitro became evaginated and had hooks, presumptive suckers and stalks. Degenerative changes of protoscoleces were evidenced after treatment with praziquantel and nano-combination. Protoscoleces treated with praziquantel had distinct attestation of necrosis and nano-combination-treated protoscoleces had signatures of apoptosis.
Relativistic self distortion of a Gaussian laser pulse in inhomogeneous plasma in one dimension is investigated. The relativistic mass effect causes different portions of the pulse to travel with different group velocities leading to the steepening of the pulse front and broadening of the rear. This asymmetry created in the pulse shape gives rise to stronger ponderomotive force on electrons at the front and weaker at the rear. The fast moving electrons under this force are shown to have very significant net energy gain. The energy gain increases with the density scale-length and then saturates.
Fasciola gigantica fatty acid binding protein (FABP) was evaluated for evoking an effective immune response in mice and rabbits, when delivered as a DNA vaccine in muscle cells. Polyethylenimine (PEI), 25 kDa, branched cationic polymer was used as a delivery vehicle for this DNA in the muscle cells of mice and rabbits. Naked DNA evoked mixed Th1 and Th2 responses in mice. PEI condensed DNA, at amine nitrogen over DNA phosphate (N/P) ratios of 4, 6 and 8 and with various DNA concentrations, failed to evoke a significantly higher antibody response compared to naked DNA in mice. Similarly, the humoral immune response to naked DNA administration in rabbit thigh muscles was poor and no boosting of this antibody response on administration of DNA complexed to PEI was observed. On metacercarial challenge, rabbits failed to show any significant protective immune response in both the naked DNA and PEI–DNA immunized groups. Administration of PEI alone (12.5 μg) in mouse thigh muscles caused significant muscle cytotoxicity but condensation of DNA with PEI had less of a toxic effect on muscle cells, which was inversely related to the N/P ratio. Delivery of plasmid DNA encoding F. gigantica FABP by high molecular weight polyethylenimine (branched, 25 kDa) did not boost the effective immune response in both the animal species, which could either be attributed to cytotoxicity associated with this cationic polymer or muscle cells being unsuitable target cells for PEI condensed DNA delivery.
In vitro trials investigating the effects of albendazole and triclabendazole anthelmintics on the growth profiles of the egg-parasitic fungi Paecilomyces lilacinus and Verticillium chlamydosporium were undertaken. In addition, in vivo trials were conducted in goats fed on millet grain cultures of each fungus and administered albendazole and triclabendazole anthelmintics. In vitro growth revealed V. chlamydosporium to be more sensitive to albendazole compared to P. lilacinus. In contrast, triclabendazole had the least inhibitory effect on in vitro growth of both P. lilacinus and V. chlamydosporium. Similar to albendazole, growth of P. lilacinus was more vigorous at 0.5 ppm concentration of triclabendazole. Efforts to re-isolate these egg-parasitic fungi from faeces of goats fed on fungal millet grain cultures before and following single intraruminal administration of albendazole and triclabendazole showed that P. lilacinus was not able to be re-isolated from the faeces at any sampling period. In contrast, V. chlamydosporium was able to be re-isolated from the faeces at all of the sampling periods except for the samples taken at 8–18 h and 18–24 h after administration of albendazole and triclabendazole, respectively. Lack of fungal activity at these times coincided with peak plasma availability of anthelmintics and suggests faecal levels of drugs were also high at these times and impacted negatively on fungal viability.
The forest canopy, biomass, and basal tree-trunk cover, of an area of about 200,000 ha, comprising 10 subcatchments in the Indian Central Himalaya, were mapped by employing aerial photographs and non-destructive field sampling. This method provides basic information on the current forest land-use and biomass for enlightened environmental planning and conservation. Regression equations developed to describe predictive relationships between crown-cover and basal tree-trunk cover; biomass and crown-cover; basal tree-trunk cover and bole biomass; and basal tree-trunk cover and total above-ground biomass, for different forests occurring in the area, should prove of value for future ecological studies in the Central Himalaya.
Black-and-white aerial photographs were used to map the lithology, land-use/forest types, and landslide zones (namely old, active, or potential) in a part of Central Himalaya. The landslide and land-use/forest type maps were simultaneously studied, and the frequency distribution of the landslide zones in different land-uses and forest types was estimated. The correlation between the maps indicated the following: In old landslide-affected sites, agriculture was the predominant land-use, followed by Pinus roxburghii forest (≤ 40% crown cover), scrub vegetation, and wasteland (including grassland). The presence of other forests (e.g. forests dominated by climax species such as Shorea robusta at low elevations and Quercus spp. at higher elevations) indicates a high potentiality of recovery of the ecosystems involved, provided biotic (especially anthropic) factors are not too intensive.
The active and potential landslide zones were concentrated along geologically active planes, namely thrusts and faults, and/or in the vicinity of toe-erosion of hill-slopes. These two were dominated by P.roxburghii forest (≤ 40% crown cover). The broadleaf forests showed minimal signs of active and potential landslides, perhaps because of their multistratal character which is conducive to minimizing soil-loss compared with the mostly single-storeyed Chir Pine forest. It is, therefore, suggested that the sites should be maintained under a multistratal broadleaf canopy to conserve the soil. Where, however, the Chir Pine forest is already developed, appropriate silvicultural measures may be taken to increase its crown cover to more than 40%.
Most of the features that are commonly attributed to typical tropical rain-forests, such as a preponderance of woody vegetation and species with leaves in the mesophyll size-class, tall slender trees with ‘flying buttress’ and unusually thin bark, multilayering of vegetation with abundance of epiphytes and stranglers, evergreenness, strong tendency to change in species composition in time and space, and high diversity of dominance, are plentifully displayed by the forests of the Silent Valley in southwestern India. A relatively high species-richness, remarkably thin bark of trees, and high total tree-basal area, indicate that the valley embodies a virgin forest and that conditions for growth are very favourable. Because of the terrain, heterogeneity in habitats is well marked.
The proposed construction of a dam and large flooding reservoir threatens to bring about several undesirable alterations in the environment of the Silent Valley rain- and riparian forests, and the disturbances that would follow such construction and flooding would be highly detrimental to the diversity of the forests and to the complexity of their structure. Hence a plea is made for the setting aside forthwith of a proposed major ‘Silent Valley Biosphere Reserve’, which could safeguard a unique part of the world's genetical heritage and one of its most interesting complexes of natural ecosystems.
A significant effect of moon phase on light-trap catches of Anopheles species was observed during a longitudinal study carried out in a forested belt of Madhya Pradesh, India, inhabited by tribal people. However, moon phase does not seem to have any effect on the proportion of adult Anopheles culicifacies Giles in the total catch, or the parity rate in this species, which is the vector responsible for perennial transmission of malaria in the area.
A differential equation governing the wakefield potential (φ) in a plasma filled rectangular waveguide is derived analytically. This equation is solved numerically for the wakefield (Ew) generated with the help of three kinds of microwave pulses, namely sine pulse (SP), rectangular Gaussian pulse (RGP), and rectangular triangular pulse (RTP). The effect of microwave frequency (f), pulse duration (τ), waveguide width (b), equilibrium plasma density (n0), and microwave intensity (I) on the amplitude of the wakefield is studied. This amplitude is increased for the longer pulse duration and higher microwave intensity, but is decreased with growing waveguide width for all types of pulses. With regard to the variation of wakefield amplitude with plasma density, the RTP and SP behave in a similar fashion and the RGP behaves oppositely. The amplitude for the case of RGP gets increased with the plasma density. The amplitude is enhanced at larger microwave frequency for the cases of RGP and SP, but is decreased for the case of RTP. The comparative study of three types of pulses shows that the wakefield with larger amplitude is achieved with the help of rectangular triangular pulse, which is found to be sensitive with waveguide width, pulse duration and microwave intensity.