183 research outputs found

    SARAS 2: A Spectral Radiometer for probing Cosmic Dawn and the Epoch of Reionization through detection of the global 21 cm signal

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    The global 21 cm signal from Cosmic Dawn (CD) and the Epoch of Reionization (EoR), at redshifts z630z \sim 6-30, probes the nature of first sources of radiation as well as physics of the Inter-Galactic Medium (IGM). Given that the signal is predicted to be extremely weak, of wide fractional bandwidth, and lies in a frequency range that is dominated by Galactic and Extragalactic foregrounds as well as Radio Frequency Interference, detection of the signal is a daunting task. Critical to the experiment is the manner in which the sky signal is represented through the instrument. It is of utmost importance to design a system whose spectral bandpass and additive spurious can be well calibrated and any calibration residual does not mimic the signal. SARAS is an ongoing experiment that aims to detect the global 21 cm signal. Here we present the design philosophy of the SARAS 2 system and discuss its performance and limitations based on laboratory and field measurements. Laboratory tests with the antenna replaced with a variety of terminations, including a network model for the antenna impedance, show that the gain calibration and modeling of internal additives leave no residuals with Fourier amplitudes exceeding 2~mK, or residual Gaussians of 25 MHz width with amplitudes exceeding 2~mK. Thus, even accounting for reflection and radiation efficiency losses in the antenna, the SARAS~2 system is capable of detection of complex 21-cm profiles at the level predicted by currently favoured models for thermal baryon evolution.Comment: 44 pages, 17 figures; comments and suggestions are welcom

    IMPACT OF ALCOHOL ON PANCREAS IN ALCOHOLIC PATIENTS

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    Objective: Prolonged hazardous drinking can result in progressive and irreversible damage to the pancreas gland. This occurs on the background of pancreatic inflammation, acinar atrophy and, ultimately, fibrosis and can result in significant exocrine and endocrine insufficiency. Withdrawal of alcohol at an early stage may arrest the process and, even when the condition is established, may reduce the number of inflammatory episodes and allow for better control of both exocrine and endocrine insufficiencies. This study is aimed to identify the impact of alcohol on the pancreas and to educate the patient about the importance of alcohol cessation. Methods: A retrospective study was conducted in a multispecialty clinic in the gastroenterology department for a period of one month. 60 patients were involved in the study who were diagnosed with pancreatitis (acute or chronic). The data was obtained by directly communicating with the patients which consisted of demographics and social habits. Results: Among 60 patients, the male was dominant (85%) than female (15%). Majority of the patients were in the age group of 41-60 y (65%) followed by patients 2140 y of age (25%) and patients above 60 y of age (10%). Epigastric pain was the most common presenting complaint in all patients (67%) followed by vomiting (33%). Majority of the patients involved are alcoholics (60%). Conclusion: Proper attention to the health at the time of diagnosis of disease by alcohol cessation can prevent the progression of the disease and helps the patient to lead a healthy life

    Profile of patients with intellectual disability visiting a tertiary care center in western India

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    Background:Intellectual disability is commonly associated with variety of etio-pathological and co-morbid conditions influencing outcome of rehabilitative measures. Understanding of these factors helps in better management of disabled condition.Methods:A qualitative retrospective case record review, of patients with intellectual disability, visiting psychiatry department of a tertiary care hospital, within a period of one year, was conducted to assess their epidemiological and clinical profile.Results: Patients with Intellectual disability are brought to the hospital at all ages and commonly by their parents. Etiologically related various peri-natal factors (delayed birth cry and seizures being most common) as well as childhood medical conditions (epilepsy and recurrent respiratory/GI infections being most common) were commonly found in these patients. Milestones are delayed in almost 60-70% of cases whereas various physical and psychiatric conditions commonly co-existed with disability.Conclusion:Clinical profile of these patients demands a comprehensive evaluation and management apart from routine IQ assessment

    Anti-Herpes Simplex Virus (HSV-1 and HSV-2) activity of biogenic gold and silver nanoparticles using seaweed Sargassum wightii

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    1252-1257Biogenic gold (Au) and silver (Ag) nanoparticles were synthesized using seaweed Sargassum wightii (Sw) and their antiviral activity against Herpes Simplex Virus (HSV-1 and HSV-2) was evaluated. Efficacy of Sw-Au and Sw-Ag nanoparticles against HSV was estimated by the reduction of cytopathic effect (CPE) caused by HSV, which was observed in a dose-dependent manner. Sw-Au nanoparticles reduced 70% CPE of HSV-1 and HSV-2 at 10 μL and 25 μL, respectively, whereas 2.5 μL Sw-Ag nanoparticles effectively reduced 70% CPE of HSV-1 and HSV-2. Cytotoxicity was estimated in Vero cells by MTT assay. Sw-Au nanoparticles were significantly non-toxic in all the concentrations tested, whereas Sw-Ag nanoparticles were found to be toxic in higher concentrations. Sw-Au nanoparticles showed cell viability of 93.12-85.18 % in the range of 2.5-25 µL, and Sw-Ag nanoparticles showed cell viability of 97.21-21.91% in the range of 1-10 μL. Sw-Au and Sw-Ag nanoparticles effectively reduce the CPE caused by both HSV-1 and HSV-2 in Vero cells and can be used to treat HSV infections

    INTEND AND PROPOSE THE HIGH SPEED LFSR CIRCUIT USING SST METHOD

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    Linear feedback shift register (LFSR) is an important component of the cyclic redundancy check (CRC) operations and BCH encoders. This thesis presents a mathematical proof of existence of a linear transformation to transform LFSR circuits into equivalent state space formulations. This transformation achieves a full speed-up compared to the serial architecture at the cost of an increase in hardware overhead. This method applies to all irreducible polynomials used in CRC operations and BCH encoders. A new formulation is proposed to modify the LFSR into the form of an CRC filter. We propose a novel high speed parallel LFSR architecture based on parallel Infinite Impulse Response (CRC) filter design, pipelining and retiming algorithms. The advantage of proposed approach over the previous architectures is that it has both feedforward and feedback paths. We further propose to apply combined parallel and pipelining techniques to eliminate the fanout effect in long generator polynomials. The proposed scheme can be applied to any generator polynomial, i.e., any LFSR in general. A comparison between the proposed and previous architectures shows that the proposed parallel architecture achieves the same critical path as that of previous designs with a reduced hardware cost

    Rare histological types of bladder carcinoma from a tertiary care hospital: Case reports

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    Bladder carcinoma is one of the most common urological malignancies with many rare histological variants associated with various prognosis. The recognition of these rare histological variants of bladder carcinoma may be helpful in selecting appropriate therapeutic approach and to predict the prognosis of the patients. We present three such rare entities of urothelial carcinoma with squamous differentiation, squamous cell carcinoma of bladder and metastatic bladder carcinoma which are associated with bad prognosis
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