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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.
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.
Hexane extracts of 10 different varieties of tomato (Lycopersicon esculentum Mill) obtained in the vegetative and flowering periods were studied for synomonal response of the egg parasitoid Trichogramma chilonis Ishii. Gas chromatography of leaf extracts revealed the presence of saturated hydrocarbons ranging from C14 to C29 in varying numbers and concentrations. These hydrocarbons elicited varied synomonal responses from the parasitoid. The quantity of individual hydrocarbons varied from 72 to 34,940 ppm in the vegetative period and from 4 to 46,170 ppm in the flowering period. Hexane extracts obtained during the flowering period showed a greater synomonal response compared with those obtained during the vegetative period. A better response observed for certain varieties of tomato at a particular period could be due to the presence of higher concentrations of favourable hydrocarbons relative to unfavourable ones. Synomonal activity seems to be associated mainly with tricosane, heneicosane, pentacosane and hexacosane during the vegetative period and with heneicosane and hexacosane during the flowering period. In the vegetative period, the tomato variety To-Pant-T4 elicited the highest activity as well as parasitism at the lowest concentration of 25,000 ppm, which was higher than other varieties at all concentrations. Varieties To-BT-116-32, To-BT-20-2-1 and To-Pant-T3 in the vegetative period and To-Selection-15, To-Selection-32 and To-BT-22-2-1 in the flowering period elicited higher responses than the other varieties. To-BT-20-2-1 elicited a maximum response in the flowering period, which may be due to the presence of higher relative quantities of tricosane, heneicosane and hexacosane. In view of these findings, tomato varieties with favourable semiochemicals could be exploited in an integrated pest management programme to enhance the effectiveness of the egg parasitoid T. chilonis against the fruit borer Helicoverpa armigera (Hb).
This paper presents a sequential evaluation of snow microstructure and its associated thermal conductivity under the influence of a temperature gradient. Temperature gradients from 28 to 45 Km–1 were applied to snow samples having a density range 180–320 kgm–3. The experiments were conducted inside a cold room in a specially designed heat-flux apparatus for a period of 4weeks. A constant heat flux was applied at the base of the heat-flux apparatus to produce a temperature gradient in the snow sample. A steady-state approach was used to estimate the effective thermal conductivity of snow. Horizontal and vertical thick sections were prepared on a weekly basis to obtain snow micrographs. These micrographs were used to obtain snow microstructure using stereological tools. The thermal conductivity was found to increase with increase in grain size, bond size and grain and pore intercept lengths, suggesting a possible correlation of thermal conductivity with snow microstructure. Thermal conductivity increased even though surface area and area fraction of ice were found to decrease. The outcome suggests that changes in snow microstructure have significant control on thermal conductivity even at a constant density.
This study was carried out on 2 309 households in 60 villages with the objective of documenting the performance of Mecheri sheep in their native environment. The study revealed that Mecheri sheep were distributed in Salem, Erode, Karur, Namakkal and parts of Dharmapuri districts of Tamil Nadu. This tract lies in the north-western agro-climatic zone of Tamil Nadu and the climate is generally hot, semi-arid and tropical in nature.
The average flock size of Mecheri sheep was 24, of which, there were 1 ram, 17 ewes and 6 lambs. Mecheri sheep of medium size with a compact body and covered with short hairs, which are not shorn. They are light brown in colour. Their profile reveals a slightly Roman nose. Both males and females are polled. The pooled means for height at withers, chest girth and body length at above 24 months of age were 67±0.4, 74±0.4 and 66±0.4 cm, respectively. The body weight of the animals at birth 3, 6, 9 and 12 months of age was 2.82±0.01, 10.9±0.1, 15.6±0.1, 17.6±0.2 and 21.1±0.1, kg respectively. The dressing percentage of males and females was 54.4±0.4 and 51.8±0.5, respectively. Average ages at first oestrus, mating and lambing were 12.1±0.1, 12.4±0.1 and 17.4±0.1 months, respectively. The average lambing interval was 226±0.7 days and the average litter size was one.
Nanocrystalline tungsten oxide (WO3) films were electrodeposited potentiostatically at room temperature on transparent conducting substrates from an ethanolic solution of acetylated peroxotungstic acid prepared from a wet chemistry process. The changes that occur in the microstructure and the grain size of the as-deposited WO3 films as a function of annealing temperature are simultaneously accompanied by a continually varying electrochromic performance. X-ray diffraction studies revealed the transformation of a nanocrystalline as-deposited WO3 film into a highly crystalline triclinic WO3 as the annealing temperature was raised from room temperature to 500 °C. The microstructural evolution with the increasing annealing temperature of the as-deposited film was further exemplified by transmission electron microscopy (TEM) studies. While the as-deposited film was composed of uniformly distributed ultra fine nanograins, the most noticeable feature seen in these films annealed at 250 °C was the presence of open channels which are believed to promote lithium ion motion. Films annealed at 400 °C exhibited coarse grains with prominent grain boundaries that hinder lithium ion movement, which in turn reduces the film’s ion insertion capacity. In concordance with the TEM results, the 250 °C film had the highest ion storage capacity as it exhibited a charge density of 67.4 mC cm−2 μm−1. The effect of microstructure was also reflected in the high transmission modulation (64%) and coloration efficiency (118 cm2 C−1) of the 250 °C film at 632.8 nm. Contrary to the superior electrochromic performance of the 250 °C film, the optical switching speeds between the colored and bleached states of the as-deposited WO3 film declined considerably as a function of annealing temperature. Also, the diffusion coefficient for lithium ions was greater by at least an order of magnitude for the as-deposited film as compared to the 250 and 500 °C films. In this report, the influence of microstructural changes that are brought about by the annealing of the as-deposited WO3 films on their coloration-bleaching dynamics is evaluated in terms of their structural, electrochromic, and electrochemical properties.