3,515 research outputs found

    Generators for vector bundles on generic hypersurfaces

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    We prove that on a generic hypersurface in Pm+1 of dimension at least 3, a vector bundle with r ≤ m generators must be split if m is odd. If m is even, then the same is true if the degree of X is at least 3

    Determination of Nonlinear Refractive Index of Zinc Phthalocyanine by Pump Induced Fizeau Interferometry

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    Experimental measurement of intense light induced refractive index is demonstrated using Fizeau interferometer. Refractive index is induced in a specific region of the sample with intense light pulse of a linearly polarized, Q- switched Nd:YAG laser at 1064nm wavelength. The respective change in optical path difference (OPD) is measured using Fizeau interferometer. The OPD so obtained is mapped in terms of change in refractive index in the area of interaction of pump beam and sample. The measured induced refractive index is then used to calculate thermo-optic coefficient of the ZnPc embedded polymeric sample

    Wheat Genomics: Present Status and Future Prospects

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    Wheat (Triticum aestivum L.), with a large genome (16000 Mb) and high proportion (∼80%) of repetitive sequences, has been a difficult crop for genomics research. However, the availability of extensive cytogenetics stocks has been an asset, which facilitated significant progress in wheat genomic research in recent years. For instance, fairly dense molecular maps (both genetic and physical maps) and a large set of ESTs allowed genome-wide identification of gene-rich and gene-poor regions as well as QTL including eQTL. The availability of markers associated with major economic traits also allowed development of major programs on marker-assisted selection (MAS) in some countries, and facilitated map-based cloning of a number of genes/QTL. Resources for functional genomics including TILLING and RNA interference (RNAi) along with some new approaches like epigenetics and association mapping are also being successfully used for wheat genomics research. BAC/BIBAC libraries for the subgenome D and some individual chromosomes have also been prepared to facilitate sequencing of gene space. In this brief review, we discuss all these advances in some detail, and also describe briefly the available resources, which can be used for future genomics research in this important crop

    Influence of the downwash airflow in Hexacopter Drone on the spray distribution pattern of boom sprayer

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    The spray characteristics of drone sprayers are significantly influenced by the downwash airflow produced by Drone multi-rotors. The present study aimed to study the influence of downwash airflow and the operational parameters of Drone sprayer, viz., flight height, travel speed, rotor configuration, payload and wind velocity on the spray distribution pattern for boom sprayer attachment to Drone. The boom type sprayer consisted of four numbers of flat fan nozzles placed at three different spacing viz., 30, 45 and 60 cm between each nozzle. The spray distribution pattern of the Hexacopter Drone was studied at three different operating pressures, viz., 3.0, 4.0 and 5.0 kg cm-2. A spray patternator of 5 m x 5 m was developed per the Bureau of Indian Standards (BIS) standard to study the spray uniformity of volume distribution pattern. The best spray uniformity was found as 0.37 % CV value at 60 cm nozzle spacing and 4 kg cm-2 operating pressure. The optimised parameters viz., 60 cm of nozzle spacing and 4 kg cm-2 operating pressure, the influence of downwash airflow on the spray volume distribution of hexacopter Drone with boom spray attachment were studied. The Drone hovered at three different heights, viz., 1.0, 2.0 and 3.0 m from the top of the patternator and spray operating pressure was maintained at 4 kg cm-2. It was observed that less volume of spray was collected at the middle portion when the Unmanned Aerial Vehicle (UAV) was hovered at 1.0 m height due to the direct impact of downwash airflow of rotors. The uniform spray volume distribution pattern was observed when Drone hovered from 1.0 m to 3.0 m height. A round vertex pattern of spray pattern was generated with boom type nozzles configuration due to the direct impact of downwash airflow of rotors. This study will be helpful in the configuration of nozzles attached to the drone sprayers, optimization of spray operational parameters, and revealing spray volume distribution pattern

    Loss of genetic diversity and inbreeding in Kashmir red deer (Cervus elaphus hanglu) of Dachigam National Park, Jammu & Kashmir, India

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    BACKGROUND: Hangul (Cervus elaphus hanglu), the eastern most subspecies of red deer, is now confined only to the mountains in the Kashmir region of Jammu & Kashmir State of India. It is of great conservation significance as this is the last and only hope for Asiatic survivor of the red deer species in India. Wild population of free ranging hangul deer inhabiting in and around Dachigam National Park was genetically assessed in order to account for constitutive genetic attributes of hangul population using microsatellite markers. RESULTS: In a pool of 36 multi-locus genotypes, 30 unique individuals were identified based on six microsatellite loci. The estimated cumulative probability of identity assuming all individuals were siblings (P(ID) sibs) was 0.009 (9 in 1000). Altogether, 49 different alleles were observed with mean (± s.e.) allelic number of 8.17 ± 1.05, ranging from 5 to 11 per locus. The observed heterozygosity ranged between 0.08 and 0.83, with mean 0.40 ± 0.11 and the inbreeding coefficient ranged between −0.04 and 0.87 with mean 0.38 ± 0.15. Majority of loci (5/6) were found to be informative (PIC value > 0.5). All loci deviated from Hardy-Weinberg equilibrium except Ca-38 (P > 0.05) and none of the pairs of loci showed significant linkage disequilibrium except the single pair of Ca-30 and Ca-43 (P < 0.05). CONCLUSIONS: The preliminary findings revealed that hangul population is significantly inbred and exhibited a low genetic diversity in comparison to other deer populations of the world. We suggest prioritizing the potential individuals retaining high heterozygosity for ex situ conservation and genetic monitoring of the hangul population should be initiated covering the entire distribution range to ensure the long term survival of hangul. We speculate further ignoring genetics attributes may lead to a detrimental effect which can negatively influence the reproductive fitness and survivorship of the hangul population in the wild

    Long-term event-free survival with an embolised prosthetic valve leaflet in the thoracic aorta

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    We report the case of a patient who underwent a redo surgery for a leaflet escape from a Bjork-Shiley tilting disc mitral prosthesis inserted 18 years previously. The escaped disc remained lodged in the thoracic aorta without any complication. She ultimately died of terminal heart failure 13 years after the second operation. We believe this to be the longest survival with a dislodged leaflet from a mechanical valve. Removal of dislodged disc is recommended in literature but there may be a place for watchful observation in exceptional cases with no haemodynamic compromise
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