577 research outputs found
Redescription of Steinernema scapterisci Nguyen and Smart, 1990: (Steinernematidae)
Present communication deals with redescription of the insect parasitic nematode, Steinernema scapterisci Nguyen and Smart, 1990, collected from the mole cricket, Gryllotalpa africana at Khurja, district (U.P.). The original description suffers from some morphological variations in the testis, tail and vulvular region
A Green's function approach to transmission of massless Dirac fermions in graphene through an array of random scatterers
We consider the transmission of massless Dirac fermions through an array of
short range scatterers which are modeled as randomly positioned -
function like potentials along the x-axis. We particularly discuss the
interplay between disorder-induced localization that is the hallmark of a
non-relativistic system and two important properties of such massless Dirac
fermions, namely, complete transmission at normal incidence and periodic
dependence of transmission coefficient on the strength of the barrier that
leads to a periodic resonant transmission. This leads to two different types of
conductance behavior as a function of the system size at the resonant and the
off-resonance strengths of the delta function potential. We explain this
behavior of the conductance in terms of the transmission through a pair of such
barriers using a Green's function based approach. The method helps to
understand such disordered transport in terms of well known optical phenomena
such as Fabry Perot resonances.Comment: 22 double spaced single column pages. 15 .eps figure
An efficient method for generating a germ cell depleted animal model for studies related to spermatogonial stem cell transplantation
Background: Spermatogonial stem cell (SSC) transplantation (SSCT) has become important for conservation of endangered species, transgenesis and for rejuvenating testes which have lost germ cells (Gc) due to gonadotoxic chemotherapy or radiotherapy during the prepubertal phase of life. Creating a germ cell-depleted animal model for transplantation of normal or gene-transfected SSC is a prerequisite for such experimental studies. Traditionally used intraperitoneal injections of busulfan to achieve this are associated with painful hematopoietic toxicity and affects the wellbeing of the animals. Use of testicular busulfan has been reported recently to avoid this but with a very low success rate of SSCT. Therefore, it is necessary to establish a more efficient method to achieve higher SSCT without any suffering or mortality of the animals. Methods: A solution of busulfan, ranging from 25 μg/20 μl to 100 μg/20 μl in 50 % DMSO was used for this study. Each testis received two diagonally opposite injections of 10 μl each. Only DMSO was used as control. Germ cell depletion was checked every 15 days. GFP-expressing SSC from transgenic donor mice C57BL/6-Tg (UBC-GFP) 30Scha/J were transplanted into busulfan-treated testis. Two months after SSCT, mice were analyzed for presence of colonies of donor-derived SSC and their ability to generate offspring. Results: A dose of 75 μg of busulfan resulted in reduction of testis size and depletion of the majority of Gc of testis in all mice within 15 days post injection without causing mortality or a cytotoxic effect in other organs. Two months after SSCT, colonies of donor-derived Gc-expressing GFP were observed in recipient testes. When cohabitated with females, donor-derived offspring were obtained. By our method, 71 % of transplanted males sired transgenic progeny as opposed to 5.5 % by previously described procedures. About 56 % of progeny born were transgenic by our method as opposed to 1.2 % by the previously reported methods. Conclusions: We have established an efficient method of generating a germ cell-depleted animal model by using a lower dose of busulfan, injected through two diagonally opposite sites in the testis, which allows efficient colonization of transplanted SSC resulting in a remarkably higher proportion of donor-derived offspring generation
Impact of sea breeze on wind-seas off Goa, West coast of India
After withdrawal of the Indian Summer Monsoon and until onset of the next monsoon, i.e., roughly during November-May, winds in the coastal regions of India are dominated by sea breeze. It has an impact on the daily cycle of the sea state near the coast. The impact is quite significant when large scale winds are weak. During one such event, 1-15 April 1997, a Datawell directional waverider buoy was deployed in 23 m water depth off Goa, west coast of India. Twenty-minute averaged spectra, collected once every three hours, show that the spectrum of sea-breeze-related 'wind-seas' peaked at 0.23 ±0.05 Hz. These wind-seas were well separated from swells of frequencies less than 0.15 Hz. The TMA spectrum (Bouwset al 1985) matched the observed seas spectra very well when the sea-breeze was active and the fetch corresponding to equilibrium spectrum was found to be 77±43 km during such occasions. We emphasize on the diurnal cycle of sea-breeze-related sea off the coast of Goa and write an equation for the energy of the seas as a function of the local wind
Water waves generated by a moving bottom
Tsunamis are often generated by a moving sea bottom. This paper deals with
the case where the tsunami source is an earthquake. The linearized water-wave
equations are solved analytically for various sea bottom motions. Numerical
results based on the analytical solutions are shown for the free-surface
profiles, the horizontal and vertical velocities as well as the bottom
pressure.Comment: 41 pages, 13 figures. Accepted for publication in a book: "Tsunami
and Nonlinear Waves", Kundu, Anjan (Editor), Springer 2007, Approx. 325 p.,
170 illus., Hardcover, ISBN: 978-3-540-71255-8, available: May 200
Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.
Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology
Intrahepatic cholestasis of pregnancy: maternal and fetal outcome and its correlation with serum bile acid levels
Background: Maternal, fetal, and neonatal outcomes in parturients with intrahepatic cholestasis of pregnancy (ICP) have been retrospectively documented. We aimed to present pregnancy outcomes of parturients with ICP who underwent delivery. The study was conducted during a 1-year period in a tertiary care centre.Methods: Data from 1 January to 31 December 2017 were collected to identify parturients with ICP.Results: Almost 3/4th of births came to a vaginal delivery (76.74%) and only 10 parturients had cesarean delivery. 4 of 10 parturients underwent nonelective cesarean section, while 6 had elective cesarean delivery. 15.15 % vaginal deliveries were instrumental. The most common indications for emergency LSCS and instrumental deliveries was fetal distress followed by failure to progress of labour. Most births occurred at or after 37 weeks of gestation (65%). Regarding neonatal outcomes in terms of birth weight and Apgar scores at 1 and 5 min, they were positive, as well. None of the babies had Apgar score < 7 at 5 minutes. No case of perinatal death was observed.Conclusions: Although the results were generally positive, larger studies need to be conducted to evaluate the maternal and fetal outcomes in ICP and correlation with serum bile acid levels
Role of ultrasound guided fine needle aspiration cytology of right hypochondrial masses
Background: Patients having right hypochondrial intra-abdominal masses are commonly encountered in clinical practice. The study was done to know the role of ultrasound guided fine needle aspiration in diagnosing right hypochondrial masses and its most common cause.Methods: 112 cases were collected from department of surgery, SVBP hospital meerut. FNAC was done using 22-23 G disposable lumbar puncture needle with trochar fitted with 20 ml syringe, introduced under radiological guidance and aspiration is done under negative pressure. Smears were stained with Leishman’s stain, May Grunwald Geimsa (MGG) and Papnicolou stain.Results: Out of total 112 cases, 12 cases excluded from study as only blood was aspirated. Therefore, out of 100 cases, 83% (83/100) cases were malignant, 7% (7/100) benign and 10% (10/100) inconclusive/ due to low cellularity. Among the malignant masses, majority 52 (52.0%) cases were of liver secondaries followed by 24 (24.0%) cases of adenocarcinoma gall bladder, 5 (5.0%) cases of primary hepatocellular carcinoma (HCC) and single case (1%), each of cholangiocarcinoma GB and squamous cell carcinoma GB. Among the benign lesions, 3 (3.0%) cases of liver abscess, 2 (2.0%) cases of hydatid disease followed by single case (1.0%) of hepatic adenoma and cysticercosis liver. In this study, overall accuracy of USG guided FNAC was 96.66%. Sensitivity, specificity, positive predictive value, negative predictive value and efficacy of USG guided FNAC in right hypochondrial masses were 96.66%, 100%, 100%, 66.67% and 96.87% respectively.Conclusions: USG guided FNAC is simple, quick, safe, reliable and economical tool without any significant complication in diagnosing right hypochondrial masses
Quantifying Socioeconomic and Lifestyle Related Health Risks: Burden of Cardiovascular Disease Among Indian Males
Background: Non-communicable diseases account for a significant disease burden in the South East Asia region. India is facing an increased incidence of lifestyle-related diseases, such as cardiovascular disease. Socioeconomic and lifestyle risk factors for cardiovascular disease (CVD) have been under investigated in India. This study was designed to explore risk factors contributing to the development of cardiovascular disease among Indian males.Methods: A population-based cross-sectional study was conducted among 2,235 males in the age group of 18-60 years across three states of India. A household survey was used to collect demographic and socioeconomic status information in addition to lifestyle-related attributes such as smoking, alcohol consumption, diet, and physical activity. Descriptive statistics and logistic regression were performed to identify the role of various factors that may be associated with the development of cardiovascular disease in this population.Results: The prevalence of cardiovascular disease among the male respondents contacted through a household survey was reported to be 9.8%. Logistic regression revealed that males with higher education and higher income were more likely to report CVD. With age as a strong predictor of CVD, the risk of CVD was found to be five times higher in the older age group. Current smokers were 1.3 times more likely to have CVD compared to those who never smoked. Those who were engaged in physical activity were less likely to have CVD; however, the adverse effects of smoking and excessive consumption of red meat showed a stronger association with CVD than the protective effects of physical activity.Conclusion: In developing countries, where the increase in earning capacity and change in lifestyle has been found to be accompanied by substantial risk of heart disease for males, public health measures like health promotion programs need to be implemented to decrease CVD burden
Erratum to: Quantifying Socioeconomic and Lifestyle Related Health Risks: Burden of Cardiovascular Disease Among Indian Males
During the type-setting of the final version of the article,1 the title was misspelled on the website, page 2 of Word Document, and page 2 of PDF. The title was written as “Quantifying Socioeconomic and Lifestyle Related Health Risks: Burden of Cardiocascular Disease Among Indian Males” and the corrected title is “Quantifying Socioeconomic and Lifestyle Related Health Risks: Burden of Cardiovascular Disease Among Indian Males.
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