Throughput Analysis of Primary and Secondary Networks in a Shared IEEE 802.11 System

In this paper, we analyze the coexistence of a primary and a secondary (cognitive) network when both networks use the IEEE 802.11 based distributed coordination function for medium access control. Specifically, we consider the problem of channel capture by a secondary network that uses spectrum sensing to determine the availability of the channel, and its impact on the primary throughput. We integrate the notion of transmission slots in Bianchi's Markov model with the physical time slots, to derive the transmission probability of the secondary network as a function of its scan duration. This is used to obtain analytical expressions for the throughput achievable by the primary and secondary networks. Our analysis considers both saturated and unsaturated networks. By performing a numerical search, the secondary network parameters are selected to maximize its throughput for a given level of protection of the primary network throughput. The theoretical expressions are validated using extensive simulations carried out in the Network Simulator 2. Our results provide critical insights into the performance and robustness of different schemes for medium access by the secondary network. In particular, we find that the channel captures by the secondary network does not significantly impact the primary throughput, and that simply increasing the secondary contention window size is only marginally inferior to silent-period based methods in terms of its throughput performance.Comment: To appear in IEEE Transactions on Wireless Communication

Molecular Analysis in \u3cem\u3eRauvolfia tetraphylla\u3c/em\u3e L. using RAPD Markers

The Present study reveals the molecular variations in different accessions of Rauvolfia tetraphylla L. a medicinally important plant collected from five locations of the Tirunelveli hills in Tamilnadu, India. Moleuclar analysis was carried out using RAPD markers. Out of the five primers screened, a total of 27 scorable polymorphic markers were generated. The genetic distance between the population ranged from 0.0770 to 0.3514 and the genetic identity ranged from 0.7037 to 0.9259. The overall observed and effective number of alleles is about 0.5007 and 0.3690 respectively. Nei (1978) overall genetic diversity is 0.2034. It is clear that there is distinct genetic variability in R. tetraphylla L

Pharmacognostical Study of Dioscorea oppositifolia L.

Extraction of bioactive compounds from medicinal plants permits demonstration of their physiological activity. It also facilitates pharmacology studies leading to discovery of synthesis of more potent drugs. The plant selected in the present study is Dioscorea oppositifolia L. (Dioscoreaceae) which is used traditionally for antiseptics, ulcers and abscesses. The root is chewed to cure toothache and aphthae. The whole plant extract is used for secondary syphilis and Psorasis. The present investigation was intended to evaluate the preliminary phytochemical characters and fluorescence analysis of this species

Detection and Quantification of Alternaria solani in Tomato by Real Time PCR

A conventional and real-time PCR assays using SYBR Green for the detection and quantification of A. solanihave been developed and validated. A primer set (ALP and ITS4) designed from the ITS region of A. linicola/ A. solani complex, yielded a 536 bp product when DNA from 38 isolates of A. solani were amplified. No product was amplified from A. alternata, A. brassicae, A. brassicicola, A.helianthi, A. porri, A. sesami, A.carthami, A.ricini, Colletotrichum gloeosporioides, C. capsici, C. falcatum, Cercospora canescens, C. capsici, Phytophthora infestans, Sclerotium rolfsii, Fusarium equiseti, F. oxysporum, Rhizoctonia solani, Phoma exigua, Curvularia spp and Drechslera. In addition, ALP/ITS4 primers were successfully utilized in real-time PCR assays of A. solani. The efficiency of conventional and real-time PCR assays was compared. The conventional PCR was able to detect the pathogen on symptomatic artificially infected tomato plants 5 days after pathogen inoculation. The detection limit was 100 conidia and 10 pg of DNA in the case of conventional PCR. Real-time PCR exhibited a detection limit 10 times lower (10 conidia, 10fg of DNA). The application of real time PCR assay for rapid detection of A.solani in infected tomato plant material is discussed

Compact Planar One-Shot Circular Spark Gap Switch

The fabrication and characterisation of micro spark gap switch for single shot firing applications are given in detailed . A circular switch with triggering electrode is realised on alumina substrate and can be integratable easily with the electronics for ignition applications. Circular switch is realised on 25 mil alumina substrate within substrate diameter of 10 mm. The switch measurement shows having repeatable performance of pulse peak current of around 2000 A and less than 100 ns rise time. This article details the design, development including fabrication aspects of spark switch with trigger capabilities along with characterisation of switch on alumina substrates.

Thermo-fluidic Transport Process in a Novel M-shaped Cavity Packed with Non-Darcian Porous Medium and Hybrid Nanofluid: Application of Artificial Neural Network (ANN)

In this work, an attempt has been made to explore numerically the thermo-fluidic transport process in a novel M-shaped enclosure filled with permeable material along with Al2O3-Cu hybrid nanoparticles suspended in water under the influence of a horizontal magnetizing field. To exercise the influence of geometric parameters, a classical trapezoidal cavity is modified with an inverted triangle at the top to construct an M-shaped cavity. The cavity is heated isothermally from the bottom and cooled from the top, whereas the inclined sidewalls are insulated. The role of geometric parameters on the thermal performance is scrutinized thoroughly by changing the sidewall inclination, number, and height of the top inverted triangular undulation under similar boundary conditions. The governing equations transformed into dimensionless form are solved by using a computing code written in the finite volume approach. The analysis is conducted by considering a wide range of parametric influences like sidewall angles (γ), number (n), and height (δ) of the top triangular undulations, modified Rayleigh number (Ram), Darcy number (Da), Hartmann number (Ha), and hybrid nanoparticle concentrations (φ). Furthermore, the artificial neural network (ANN) technique is implemented and tested to predict the overall thermal behavior of the novel cavity to predict new cases. The results revealed that the design of sidewall inclination (γ) is an important parameter for modulating the thermo-flow physics. The M-shaped cavity (compared to trapezoidal) reveals either a rise or drop in the fluid circulation strength depending upon the magnitude of δ, but the heat transfer rate always increases due to an increase in the cooling length. The heat transfer increment is ∼61.01% as δ increases. Single undulation with higher depth is the optimum choice for achieving improved heat transfer (which may go up to ∼355.75% for δ = 0.5 and γ  = 45°). A decrease in Da or Ha causes a drop in the flow strength, which consequently leads to a drop in the heat transfer rate. Furthermore, the concepts of ANN will help researchers predict the behavior for such complicated cavity shapes with a multiphysics approach. This will save efforts as well as computing time for exploring the thermal behavior of any range of a dataset

Drug utilization study and prescribing patterns in psychiatry patients at a tertiary care hospital

Background: The Drug utilization research (DUR) compares drug use between different countries and regions and is used to assess the rationality of prescribing pattern of the drug therapy. With this background we decided to evaluate antipsychotic drugs prescribing pattern in the psychiatric patients in a tertiary care hospital.Methods: The study was carried out at Department of Psychiatry, DSMCH. It was open label, cross - sectional, prescribed Documents based study. Duration of the study was one month (May-2017). Out-Patient number, age, sex, diagnosis, prescribed generic name, brand name, dose, route of administration, duration of therapy obtained from the Prescription register of Out - Patient Department of the Psychiatry.Results: The clinical experiences of the Psychiatrist I, II and III were 17 years, 35 years and 10 years respectively. The Psychiatrist I, II and III prescribed treatment for 36 (31.9%), 61 (54%) and 16 (14.2%) patients respectively. Among overall (n=113) patients (average age 38.9 years), male n=56 (49.6%) and female=57 (50.4%) were treated by all the three psychiatrists. The percentage of prescription of various drugs used were: Escitalopram (15.7%), Clonazepam (14.6%), Sertraline (8.7%), Risperidone (7.5%), Propranolol (6.7%), Olanzapine (6.3%), Quetiapine (5.9%), Trihexyphenidyl (5.5%), Amitriptyline (5.1%) and Other prescribed drugs, were between (0.4 to 2.8%).Conclusions: From this study, it can conclude that rational usage of drugs were followed in this study. All three prescribers (Psychiatrist I, II, and III) prescriptions were found to be rationale

Catch composition and discards in set bagnets of Karanja Estuary, Raigad, Maharashtra

Dol netting is one of the major fishing methods used mainly by traditional fishermen of Maharashtra. Study of catch composition of dol nets operated in Karanja Estuary of Raigad district, Maharashtra was carried out during September 2016 - May 2017. A total of ten single-day dol-netters were selected for the purpose of this study. Fortnightly on-board sampling and questionnaire-based sampling were carried out to fulfil the objectives of the study. The number of fishing days per month ranged from 12-16 due to tide-based restrictions. Dol net catch comprised 50 species of fin fishes, 3 species of elasmobranchs, 13 species of shrimps, 10 species of crabs, 5 species of cephalopods, 2 species of jellyfish, 4 species of sea snakes, 1 species of lobster and 2 species of stomatopods. Major catch composition of dol nets recorded during the study included Acetes indicus, Arius maculatus, Charybdis callianassa , Chrysaora Caliparea, Coilia dussumieri , Harpadon nehereus , Lepturacanthus savala , Miyakella nepa, Mystus gulio and Parapenaeopsis sculptilis. Significant discards such as jellyfishes, juveniles of several fishes and plastics were recorded in the dol nets operated in the Karanja estuar

Ofloxacin resistance in Mycobacterium tuberculosis: An increasing concern

Multidrug resistance tuberculosis (MDR-TB) associated with the development of resistance to fluoroquinolones (FQs) especially ofloxacin is a matter of concern, as they had been earlier recommended drugs for usage in the MDR-TB treatment regimens, and moxifloxacin and other quinolones are still on the list. Mycobacterium tuberculosis acquires resistance to FQs mainly through mutations in the quinolone resistance determining regions (QRDRs) of the gyrA gene and less frequently in the gyrB gene. A literature search on the geographical distribution of ofloxacin resistance in TB shows that there is a mild surge in reporting of the resistance to ofloxacin in tuberculosis patients. Molecular tests demonstrating mutations in gyrA and gyrB genes is widely used to detect ofloxacin resistance and the broadly available commercial assay for the rapid detection of second-line-drug resistance, including FQ resistance, the GenoType MTBDRsl assay (Hain Life science, Nehren, Germany), detects the most common mutations found in the QRDR of gyrA while its new version 2.0 detects mutations in the gyrB as well. It has been shown that on reviewing the frequency and geographic distribution of gyrA and gyr B mutations associated with FQ resistance, there do exist geographic differences in the frequencies within and across countries. Cross-resistance to FQs is an area of concern, although some studies show that concordance in resistance among the FQ agents, lower level of cross-resistance has also been reported. The presence of ofloxacin resistance is an alarm signal while Moxifloxacin and other FQs are still the recommended drugs for the resistant TB cases. The WHO recommendation that ofloxacin be phased out from MDR-TB regimens is well justified. It is important that rationale usage of ofloxacin is needed for preventing ofloxacin resistance, to aid in the management of tuberculosis

Total Ionizing Dose Effects on CMOS Image Sensor for the ULTRASAT Space Mission

ULTRASAT (ULtraviolet TRansient Astronomy SATellite) is a wide-angle space telescope that will perform deep time-resolved surveys in the near-ultraviolet spectrum. ULTRASAT is a space mission led by the Weizmann Institute of Science and the Israel Space Agency and is planned for launch in 2025. The camera implements backside-illuminated, stitched pixel sensors. The pixel has a dual-conversion-gain 4T architecture, with a pitch of $9.5$ $\mu m$ and is produced in a $180$ $nm$ process by Tower Semiconductor. Before the final sensor was available for testing, test sensors provided by Tower were used to gain first insights into the pixel's radiation tolerance. One of the main contributions to sensor degradation due to radiation for the ULTRASAT mission is Total Ionizing Dose (TID). TID measurements on the test sensors have been performed with a Co-60 gamma source at Helmholz Zentrum Berlin and CC-60 facility at CERN and preliminary results are presented.Comment: Part of the conference: Frontier Detectors for Frontier Physics: 15th Pisa Meeting on Advanced Detectors, La Biodola - Isola d'Elba Published in: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Available online 15 June 2023, 168463. In Press, Journal Pre-proo