This paper presents low-cost hybrid beamforming for simultaneous multiple receive beams, reducing beam-shape loss and enhancing target detection with improved accuracy for 4-D phased array radar. ...Analog Beam Forming Network (ABFN), being a critical component of the proposed architecture, is described in detail, which generates independent azimuth and elevation channels to form simultaneous multiple beams in azimuth and elevation. Herein, the output of ABFN is further combined using another set of RF manifold to reduce the number of receivers and A/D converters to 99.0% −99.5% of the total number of elements in the radar system. Grating lobe effect in multi-beam configuration, due to more than λ separation between the phase centers of linear subarrays are analyzed and optimized for multi-beam overlap and multi-beam separation. This proposed scheme reduces the cost, complexity and, at the same time, demonstrates the comparable performance of subarray level digital beamforming for multiple receive beams.
We present a general star formation law in which the star formation rate depends upon the efficiency α and the time-scale τ of star formation, and the gas component σg of the surface mass density. ...The current nominal Schmidt exponent nS for our model is 2<nS<3. Based on a gravitational instability parameter QA and another dimensionless parameter fP=(P/Gcσ2)1/2, where P = pressure and σc = column density of molecular clouds, we suggest a general equation for the star formation rate which depends upon the relative contributions of the two parameters for various physical circumstances. We find that QA turns out to be a better parameter for the star formation scenario than does the Toomre Q-parameter. The star formation rate in the solar neighbourhood is found to be in good agreement with values inferred from previous studies. In the closed box approximation model, we obtain a relationship between the metallicity of the gas and the efficiency of star formation. Our model calculations of metallicity in the solar neighbourhood agree with earlier estimates. We conclude that the metallicity dispersion for stars of the same age may result from a change in the efficiency with which different stars in the sample were processed. For no significant change of metallicity with age, we suggest that all stars in the sample were born with similar efficiencies.
Background: Gabapentin is an antiepileptic drug. Its antiemetic effect
is demonstrated in chemotherapy-induced acute and delayed onset of
nausea and vomiting in breast cancer patients. Aim: To ...evaluate the
antiemetic effect of gabapentin on incidence and severity of
postoperative nausea and vomiting in laparoscopic cholecystectomy.
Settings and Design: Double-blind, randomized, placebo-controlled
study. Materials and Methods: Two hundred and fifty patients of ASA
physical status I and II, scheduled for laparoscopic cholecystectomy
were randomly assigned into two equal groups to receive 600 mg
gabapentin or matching placebo two hours before surgery. Standard
anaesthesia technique was used. Fentanyl was used as rescue
postoperative analgesic. Ondansetron 4 mg was used intravenously as
rescue medication for emesis. The total number of patients who had
nausea or vomiting, and its severity and total fentanyl consumption in
the first 24 hours were recorded. Statistical Analysis: "Z test" was
used to test the significance of severity of post-operative nausea and
vomiting between groups. Fentanyl consumed in each group (Mean±SD)
within 24 hrs was compared using student t test. P value< 0.05 was
considered significant. Results: There were no demographic difference
between the two groups. Incidence of post-operative nausea and vomiting
within 24 hrs after laparoscopic cholecystectomy was significantly
lower in gabapentin group (46/125) than in the placebo group (75/125)
(37.8% vs 60%; P =0.04). There was a significantly decreased fentanyl
consumption in gabapentin group (221.2±92.4 µg) as compared
to placebo group (505.9±82.0 µg; P =0.01). Conclusion:
Gabapentin effectively suppresses nausea and vomiting in laparoscopic
cholecystectomy and post-operative rescue analgesic requirement.
Guava wilt disease is a severe threat to guava growers all over the world. It is caused by the soil-borne fungus Fusarium oxysporum f.sp. psidii. To control the disease, the Trichoderma-endochitinase ...gene was first introgressed into guava (Psidium guajava L.). The transgenic plantlets were screened in vitro for resistance against the wilt pathogen. Six-months-old genetically transformed plants raised in cocopeat under in vitro conditions were inoculated with a 7-days old culture of F. oxysporum f.sp. psidii. The presence of the pathogen in the cocopeat medium was confirmed by cultural as well as PCR analysis using species-specific primers. The roots of transgenic plants were wounded to facilitate the entry of the pathogen. The histopathological analysis revealed the presence of mycelium in vascular bundles. However, none of the plants showed symptoms of wilt disease during the investigation. In vitro pathogen inhibition assay and subsequently spore germination assay revealed that the crude leaf extract of transformed plants inhibited the germination of fungal conidia. The leaf tissue studied for expression of endochitinase revealed that two transgenic plants showed very high activity of N-acetyl-d-glucosamine (0.741 and 0.738 µM/min/µg of protein, respectively) which clearly indicated that transgenic plants could not develop any symptoms of wilt disease due to overexpression of endochitinase.
Genetic differences in the target proteins, metabolizing enzymes and transporters that contribute to inter-individual differences in drug response are not integrated in contemporary drug development ...programs. Ayurveda, that has propelled many drug discovery programs albeit for the search of new chemical entities incorporates inter-individual variability “Prakriti” in development and administration of drug in an individualized manner. Prakriti of an individual largely determines responsiveness to external environment including drugs as well as susceptibility to diseases. Prakriti has also been shown to have molecular and genomic correlates. We highlight how integration of Prakriti concepts can augment the efficiency of drug discovery and development programs through a unique initiative of Ayurgenomics TRISUTRA consortium.
Five aspects that have been carried out are (1) analysis of variability in FDA approved pharmacogenomics genes/SNPs in exomes of 72 healthy individuals including predominant Prakriti types and matched controls from a North Indian Indo-European cohort (2) establishment of a consortium network and development of five genetically homogeneous cohorts from diverse ethnic and geo-climatic background (3) identification of parameters and development of uniform standard protocols for objective assessment of Prakriti types (4) development of protocols for Prakriti evaluation and its application in more than 7500 individuals in the five cohorts (5) Development of data and sample repository and integrative omics pipelines for identification of genomic correlates.
Highlight of the study are (1) Exome sequencing revealed significant differences between Prakriti types in 28 SNPs of 11 FDA approved genes of pharmacogenomics relevance viz. CYP2C19, CYP2B6, ESR1, F2, PGR, HLA-B, HLA-DQA1, HLA-DRB1, LDLR, CFTR, CPS1. These variations are polymorphic in diverse Indian and world populations included in 1000 genomes project. (2) Based on the phenotypic attributes of Prakriti we identified anthropometry for anatomical features, biophysical parameters for skin types, HRV for autonomic function tests, spirometry for vital capacity and gustometry for taste thresholds as objective parameters. (3) Comparison of Prakriti phenotypes across different ethnic, age and gender groups led to identification of invariant features as well as some that require weighted considerations across the cohorts.
Considering the molecular and genomics differences underlying Prakriti and relevance in disease pharmacogenomics studies, this novel integrative platform would help in identification of differently susceptible and drug responsive population. Additionally, integrated analysis of phenomic and genomic variations would not only allow identification of clinical and genomic markers of Prakriti for application in personalized medicine but also its integration in drug discovery and development programs.
The figure illustrates stratification of individuals of a heterogeneous population into homogeneous groups through Ayurgenomics that integrates Prakriti principles of Ayurveda along with genomics and phenomics approaches. Variability in genes related to drug response amongst extreme Prakriti types identified through this approach in the present study has been depicted as an example.
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Defects with deep levels induced in high-resistivity silicon detectors by low and high radiation fluence of protons and neutrons are studied using capacitance and current DLTS. Numerical simulation ...of I-DLTS and C-DLTS spectra based on the model of charge carrier emission and redistribution of electric field in the detector enabled one to perform the detailed investigation of DLTS spectra. It has been shown that the main DLTS peak in the range of 200 to 260 K may be considered as a result of the interference of deep levels near the midgap – negatively charged divacancy VV
− and the C
i–O
i complex. The model describing the broadening of the VV
− component of the spectrum, which arises from the divacancy localization inside a cluster, is discussed. The results are compared with those obtained for gamma irradiation, for which the dominant contribution in DLTS spectra arises just from the C
i–O
i complex.
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