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Spatial distribution of rainfall and wind speed forecast errors associated with landfalling tropical cyclones (TC) occur significantly due to incorrect location forecast by numerical models. Two major areas of errors are: (i) over-estimation over the model forecast locations and (ii) underestimation over the observed locations of the TCs. A modification method is proposed for real-time improvement of rainfall and wind field forecasts and demonstrated for the typical TC AMPHAN over the Bay of Bengal in 2020. The proposed method to improve the model forecasts is a relocation method through shifting of model forecast locations of TC to the real-time official forecast locations of India Meteorological Department (IMD). The modification is applied to the forecasts obtained from the operational numerical model, the Global Forecast System (GFS) of IMD. Application of the proposed method shows considerable improvement of both the parameters over both the locations. The rainfall forecast errors due to displacement are found to have improved by 44.1%-69.8% and 72.1%-85.2% over the GFS forecast locations and over the observed locations respectively for the respective forecast lead times 48 h, 72 h, and 96 h. Similarly, the wind speed forecasts have improved by 27.6%-56.0% and 63.7%-84.6% over the GFS forecast locations and over the observed locations respectively for the respective forecast lead times 60 h, 72 h, and 84 h. The results show that the proposed technique has capacity to provide improved spatial distributions of rainfall and wind speed forecasts associated with landfalling TCs and useful guidance to operational forecasters. [ABSTRACT FROM AUTHOR]

Ozone produced by discharge or photolysis of oxygen has unusually heavy isotopic composition (18O/16O and 17O/16O ratio) which does not follow normal mass fractionation rule: S17O ~ 0.52*δ18O, expressed as an anomaly Δ17O = δ17O - 0.52*δ18O. Ozone molecule being an open isosceles triangle can have the heavy isotope located either in its apex or symmetric (s) position or the base or asymmetric (as) position. Correspondingly, one can define positional isotopic enrichment, written as δ18O (s) or δ18O (as) (and similarly for δ17O) as well as position dependent isotope anomaly Δ17O (s) and Δ17O (as). Marcus and co-workers have proposed a semi-empirical model based in principle on the RRKM model of uni-molecular dissociation but with slight modification (departure from statistical randomness assumption for symmetrical molecules) which explains many features of ozone isotopic enrichment. This model predicts that the bulk isotope anomaly is contained wholly in the asymmetric position and the Δ17O (s) is zero. Consequently, Δ17O (as) = 1.5 * Δ17O (bulk) (named here simply as the "1.5 rule") which has been experimentally confirmed over a range of isotopic enrichment. We now show that a critical re-analysis of the earlier experimental data demonstrates a small but significant departure from this 1.5 rule at the highest and lowest levels of enrichments. This departure provides the first experimental proof that the dynamics of ozone formation differs from a statistical model constrained only by restriction of symmetry. We speculate over some possible causes for the departure. [ABSTRACT FROM AUTHOR]

Oxygen and carbon isotope fractionation associated with products (CO and O2) of gas phase photodissociation of CO2 have been studied using photons from Hg lamp (184.9 nm) and Kr lamp (123.6 and 116.5 nm). In dissociation by Hg lamp photons both CO and O2 are enriched in 17O by about 81‰ compared to the estimate based on a kinetic model. Additionally, CO is enriched in 13C by about 37‰ relative to the model composition. In contrast, in dissociation by higher energy Kr lamp photons no such anomaly was found in O2. The observed isotopic enrichments in case of Hg lamp dissociation are proposed to be due to a hyperfine interaction between nuclear spin and electron spins or orbital motion causing enhanced dissociation of isotopologues of CO2 containing 17O and 13C. The 17O enrichment is higher than that of 13C by a factor of 2.2±0.2 which can be explained by the known magnetic moment ratio of 17O and 13C due to differing nuclear spins and g-factors. These results have potential implications in studies of the planetary atmospheres. [ABSTRACT FROM AUTHOR]

Atmospheric nitrate shows a large oxygen isotope anomaly (Δ 17O), characterized by an excess enrichment of 17O over 18O, similar to the ozone molecule. Modeling and observations assign this specific isotopic composition mainly to the photochemical steady state that exists in the atmosphere between ozone and nitrate precursors, namely, the nitrogen oxides (NOx=NO+NO2). However, this transfer is poorly quantified and is built on unverified assumptions about which oxygen atoms of ozone are transferred to NOx, greatly weakening any interpretation of the nitrate oxygen isotopic composition in terms of chemical reaction pathways and the oxidation state of the atmosphere. With the aim to improve our understanding and quantify how nitrate inherits this unusual isotopic composition, we have carried out a triple isotope study of the reaction NO+O3. Using ozone intramolecular isotope distributions available in the literature, we have found that the central atom of the ozone is abstracted by NO with a probability of (8±5)%(±2σ) at room temperature. This result is at least qualitatively supported by dynamical reaction experiments, the non-Arrhenius behavior of the kinetic rate of this reaction, and the kinetic isotope fractionation factor. Finally, we have established the transfer function of the isotope anomaly of O3 to NO2, which is described by the linear relationship Δ 17O(NO2)=A×Δ 17O(O3)+B, with A=1.18±0.07(±1σ) and B=(6.6±1.5)‰(±1σ). Such a relationship can be easily incorporated into models dealing with the propagation of the ozone isotope anomaly among oxygen-bearing species in the atmosphere and should help to better interpret the oxygen isotope anomaly of atmospheric nitrate in terms of its formation reaction pathways. [ABSTRACT FROM AUTHOR]

The oxygen isotope fractionation associated with O+CO→CO2 reaction was investigated experimentally where the oxygen atom was derived from ozone or oxygen photolysis. The isotopic composition of the product CO2 was analyzed by mass spectrometry. A kinetic model was used to calculate the expected CO2 composition based on available reaction rates and their modifications for isotopic variants of the participating molecules. A comparison of the two (experimental data and model predictions) shows that the product CO2 is endowed with an anomalous enrichment of heavy oxygen isotopes. The enrichment is similar to that observed earlier in case of O3 produced by O+O2 reaction and varies from 70‰ to 136‰ for 18O and 41‰ to 83‰ for 17O. Cross plot of δ 17O and δ 18O of CO2 shows a linear relation with slope of ∼0.90 for different experimental configurations. The enrichment observed in CO2 does not depend on the isotopic composition of the O atom or the sources from which it is produced. A plot of Δ(δ 17O) versus Δ(δ 18O) (two enrichments) shows linear correlation with the best fit line having a slope of ∼0.8. As in case of ozone, this anomalous enrichment can be explained by invoking the concept of differential randomization/stabilization time scale for two types of intermediate transition complex which forms symmetric (16O12C16O) molecule in one case and asymmetric (16O12C18O and 16O12C17O) molecules in the other. The δ 13C value of CO2 is also found to be different from that of the initial CO due to the mass dependent fractionation processes that occur in the O+CO→CO2 reaction. Negative values of Δ(δ 13C) (∼12.1‰) occur due to the preference of 12C in CO2* formation and stabilization. By contrast, at lower pressures (∼100 torr) surface induced deactivation makes Δ(δ 13C) zero or slightly positive. [ABSTRACT FROM AUTHOR]

Stratospheric ozone is essentially in a steady state due to the simultaneous formation and dissociation and found to be enriched (mass-independently) in heavy oxygen isotopes. Though there have been a number of experimental and theoretical studies on the mechanism(s) associated with the formation of isotopically heavy ozone, the decomposition processes were not studied in necessary detail. Here we report a novel feature in the isotopic fractionation of ozone during photodissociation in the UV and visible wavelengths. Photodissociation of ozone produces isotopically light oxygen, enriching the leftover ozone pool. Interestingly, the isotopic fractionation patterns are not similar in the two wavelength regions. Dissociation at visible wavelengths displays a mass-dependent slope (Δ δO[SUB3]SUP17]O/Δ δO[SUB3]SUP18]O = 0.54) whereas UV dissociation shows a mass-independent character (Δ δO[SUB3]SUP17]O/Δ δO[SUB3]SUP18]O = 0.63). O[SUB3] photodissociation in UV wavelengths is normally associated with another effective channel of dissociation, i.e., O[SUB3]+O([SUP1]D). It is demonstrated for the first time that pure UV photodissociation of ozone [i.e., without the O([SUP1]D) channel] gives a slope of unity intriguingly similar to that obtained in the ozone formation process. A combination of the two processes i.e., mass dependent O[SUB3] + O([SUP1]D) reaction and pure UV photodissociation is responsible for the observed slope of 0.63. [ABSTRACT FROM AUTHOR]

The isotopic enhancement of atmospheric ozone (O3) is mainly determined by two processes of formation and photolytic decomposition. The formation is known to be associated with isotopic fractionation which can be as high as 120‰ relative to the parent oxygen. Photolysis‐induced isotopic fractionation in O3, however, is not known accurately. Absorption cross sections of various ozone species have been calculated by Zero Point Energy‐based model and quantum mechanical wave packet model. But their predictions pertaining to isotopic fractionations have not been verified experimentally. In the present work, we performed irradiation experiments of O3 at several wavelengths in the Hartley and Chappuis bands and determined the dissociative isotopic fractionation factors by a Rayleigh distillation model. In laboratory conditions, photolysis of ozone produces reactive atomic and/or molecular oxygen which influence the dissociative process through secondary chemistry. The complex interplay of primary photolysis and secondary chemistry was tracked by a kinetic model, and isotopic fractionation factors associated with photolysis alone were derived within a range of uncertainties. The fractionations are found to depend on the photon wavelength and deviate significantly at some wavelengths from the predicted values. For example, at 254 nm the zero point energy‐based models predict lower photolysis rate coefficients for the lighter isotopic species; the present data show about 50‰ higher values. Key Points: Laser‐based new ozone photolysis experiments at several wavelengths at Hartley and Chappuis bands are presented to provide new insightsAlong with box modeling, the photolysis‐induced fractionation factors are derived and show distinctive values from model predictionsThe results call for urgent needs for a systematic exploration of photolysis‐induced fractionation and revisit of atmospheric applications [ABSTRACT FROM AUTHOR]

Venous aneurysm is saccular or fusiform dilatation of vein, usually congenital origin. Among acquired variety post intravenous cannulation leading to venous aneurysm is extremely rare entity. Non invasive diagnostic procedure MRI and duplex scanning are very useful modality for anatomical localization of the aneurysm. Although an ascending venogram is an invasive test and should take a backseat for diagnosis of such aneurysm. Symptometic case needs surgical management. Anatomical delineation is an important pre requisite for planning surgery. Aneurysmorrhaphy preserves the affected venous segment because it does not produce luminal compromise. [ABSTRACT FROM AUTHOR]

The isotopic composition of carbon dioxide provides a powerful tool and has been widely used for constraining the sources and sinks of atmospheric CO2. In this work, we demonstrate a simple, rapid, and clean way for measuring the triple oxygen isotope ratio of carbon dioxide with high precision. The method depends on isotope exchange between O2 and CO2 in the presence of platinum at high temperature and allows rapid measurement of Δ17O of CO2. The method has been established and confirmed through several tests by using artificially made CO2 with known Δ17O values. The analytical precision obtained for determining Δ17O in CO2 is 0.045‰ (1 - σ standard deviation). [ABSTRACT FROM AUTHOR]

Globally, pneumonia is the leading cause of death in young children and burden of disease is disproportionately high in South-East Asia Region of WHO. This review article presents the current status of pneumonia disease burden, risk factors and the ability of health infrastructure to deal with the situation. Literature survey was done for the last 20 years and data from country offices were also collected. The estimated incidence of pneumonia in under five children is 0.36 episodes per child, per year. Risk factors are malnutrition (40% in India), Indoor air pollution, non-breast feeding, chronic obstructive pulmonary disease, etc. Strengthening of health care delivery system for early detection and treatment and as well as minimization of preventable risk factors can avert a large proportion of death due to pneumonia. [ABSTRACT FROM AUTHOR]

Introduction: Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system. Aim: This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models. Materials and Methods: Adult albino mice (n=490) weighing 20-30 g and rats (n=130) weighing 100-200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects. Results: Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P<.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P<.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors. Conclusions: Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors. [ABSTRACT FROM AUTHOR]

Concentrations of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), nitrous oxide (N2O) and hydrogen (H2), and the stable carbon (δ13C-CO2) and oxygen (δ18O-CO2) isotopic composition of CO2 have been measured in air samples collected from Cabo de Rama (CRI), India, for the period 1993-2002. The observations show clear signatures of Northern and Southern Hemispheric (NH and SH) air masses, mixed with their regional fluxes and chemical loss mechanisms, resulting in complex seasonal variation of these gases. The CRI measurements are compared with remote marine sites at Seychelles and Mauna Loa. Simulations of two major anthropogenic greenhouse gases (CO2 and CH4) concentrations using a chemistry-transport model for the CRI site suggest that globally optimized fluxes can produce results comparable to the observations. We discuss that CRI observations have provided critical guidance in optimizing the fluxes to constrain the regional source/ sinks balance. [ABSTRACT FROM AUTHOR]

During the electrolysis of water in an acidified medium, ozone is produced, in association with oxygen, at the anode. This ozone is found to be depleted in heavy isotopes (18O and 17O), with respect to the source water, following a strict mass-dependent rule. Our experiments also suggest that the isotopes are distributed at the apex and base positions of the bent ozone molecule in a random fashion, without obeying the zero-point energy constraint. Endowed with these characteristics, the electrolytic ozone provides a source of reference that has a known internal heavy isotope distribution for spectroscopic studies. In addition, this ozone, when subjected to photolytic decomposition, can be used as a source of atomic oxygen with mass- dependent isotope ratios that can be varied by simply changing the water composition. Such an oxygen source is important for studying isotope effects in gas-phase recombination/exchange reactions such as COO + O* - [COOO*] - COO* + O. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in experimental animals exposed to cocaine. Materials and Methods: Mice were used in this study and were divided randomly into different groups of six animals each. They were either treated with intraperitoneal injection of saline or cocaine hydrochloride or an oral feeding of oil of Ocimum sanctum, ascorbic acid or verapamil, or both (ascorbic acid and verapamil), and were evaluated for a respiratory burst of macrophages, superoxide and nitric oxide (NO) production, estimation of TNF-a in the serum and supernatant of cultured macrophages, estimation of lipid peroxidation (malondialdehyde- MDA) in the serum, and superoxide dismutase activity in the erythrocytes. Results: Unstimulated respiratory burst as well as superoxide production was enhanced on treatment with cocaine and all the three drugs were found to attenuate this enhancement. The bactericidal capacity of macrophages decreased significantly on chronic cocaine exposure, as it was associated with decreased respiratory burst and superoxide production. There was a significant decrease in NO production by macrophages on chronic cocaine exposure and all the test drugs were found to restore nitrite formation to a normal level. There was an increase in the malonylodialdehyde (MDA) level and decrease in the superoxide dismutase level on chronic cocaine exposure, and all the three drugs effectively decreased the MDA level and increased superoxide dismutase level. There was an increase in serum TNF-a on chronic cocaine exposure, which was decreased significantly by ascorbic acid and verapamil. Conclusion: O. sanctum, ascorbic acid, and verapamil were equally effective in improving the macrophage function and reducing oxidative stress. These findings suggested that O. sanctum, ascorbic acid, and verapamil attenuated acute and chronic cocaine-mediated effects. [ABSTRACT FROM AUTHOR]

Understanding the internal distribution of "anomalous" isotope enrichments has important implications for validating theoretical postulates on the origin of these enrichments in molecules such as ozone and for understanding the transfer of these enrichments to other compounds in the atmosphere via mass transfer. Here, we present an approach, using the reaction NO2- + O3, for assessing the internal distribution of the Δ17O anomaly and the δ18O enrichment in ozone produced by electric discharge. The Δ17O results strongly support the symmetry mechanism for generating mass independent fractionations, and the δ18O results are consistent with published data. Positional Δ17O and δ18O enrichments in ozone can now be more effectively used in photochemical models that use mass balance oxygen atom transfer mechanisms to infer atmospheric oxidation chemistry. [ABSTRACT FROM AUTHOR]

The issue of protection system coordination in reconfigurable distribution systems is dealt with in this article. The protection coordination requirement restricts the changes in the power-flow direction through the distribution lines and drastically reduces the search space to be explored by the network reconfiguration algorithms. Moreover, the protection system for the reconfigurable distribution network has to be designed considering all permissible configurations of the network. This article illustrates the protection design procedure through a test network and presents a network reconfiguration algorithm incorporating the protection coordination constraints. [ABSTRACT FROM AUTHOR]

Pollen, C/N ratios and δ13COM from a 1.2 m thick palaeolake deposit at Sangla, Kinnaur, Himachal Pradesh provide records of climatic changes during the past 10,000 years. The C/N ratios together with pollen data indicate high lake level between 10,000 and 4,000 yrs BP. Following this, an increase in δ13C (+2‰) indicates stressed climatic conditions, whereby δ13COM attained a value of -23‰, being the maximum for the available record. This event is bracketed between 3500 and 1500 yrs BP. Subsequently, the lake underwent a few dry spells ca. 1000 yrs BP. Finally, it got completely desiccated around 800 yrs BP. [ABSTRACT FROM AUTHOR]

The instability of ion-acoustic waves has been theoretically studied in a multicomponent plasma consisting of positive ions, negative ions and two-temperature isothermal electrons, and also considering the streaming of ions through the derivation of dispersion relation in an unbounded and bounded system involving a comparative study between the results obtained in the two cases. Results for the phase velocity and the instability have been graphically illustrated for the plasmas (O[sup -],Ar[sup +]) and (Cl[sup -],H[sup +]). © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The article points and corrects the errors found in the research paper "Anomalous oxygen isotope enrichment in CO2 produced from O+CO: Estimates based on experimental results and model predictions."

Background: Recent animal experiments and clinical trials have shown that both osmolarity and rice as the organic components are important factors for net intestinal absorption of an oral rehydration salt solution. Methods: In a controlled clinical trial 123 male adult patients with severe cholera, after initial rehydration with intravenous Ringer's lactate solution, were randomly assigned to receive one of the four oral rehydration salt solutions: WHO ORS, ORS containing 70 mmol/l Na[sup +] and 16.2 g/l glucose, rice ORS containing 50 g/l rice and 90 mmol/l Na[sup +], and rice ORS containing 50 g/l rice and 70 mmol/l Na[sup +]. All patients received 300 mg of doxycycline as a single dose. Results: Patients who received rice-low-sodium ORS subsequently had lower (P < 0.05) stool output, ORS consumption, and diarrhoea duration than the other three ORS groups. Conclusions: We conclude that rice-based low-sodium ORS is superior for treating adult cholera. [ABSTRACT FROM AUTHOR]

A new discrete distribution arising from a Poisson distribution when the prior distribution of the parameter involved in uniform, has been obtained and its application in an accident proneness model is indicated. The posterior distribution of the parameter turns out to be a truncated gamma distribution and it is noted that the posterior distribution corresponding to a truncated prior distribution is simply the truncation of the posterior corresponding to the untruncated prior. [ABSTRACT FROM AUTHOR]

Among the natural ecosystems, forests and wetlands emit a sizable amount of carbon dioxide (CO2) and methane (CH4) through autotrophic and heterotrophic respiration and bacterial activities. Interestingly, some evidence suggests that a significant amount of CH4 is generated by the trees in forested ecosystems. The net ecosystem exchange (NEE), measured by the eddy covariance (EC) method, typically represents the net CO2 flux arising from the photosynthetic and respiration processes in the biosphere. This flux is subsequently partitioned into two components, the respired carbon and the assimilated carbon. However, the usual method of partitioning introduces significant errors in each of these fluxes. The present study was undertaken to address this issue where the NEE partitioning was constrained by using the carbon isotopic ratios of CO2. We used a real‐time in situ analyzer in a tropical forest in northeast India, the Kaziranga National Park. The greenhouse gas analyzer provided CO2 and CH4 concentrations, as well as their carbon isotopic ratios. The isotopic data were used to partition the EC‐derived NEE values and derive the isoflux values. Additionally, the isotopic data provided evidence of plant‐generated CH4 in conformity with some recent studies, which requires further investigation. Plain Language Summary: The terrestrial vegetation absorbs a vast amount of carbon in the photosynthetic process. They also emit a sizeable amount of carbon through respiration. Eddy‐covariance‐based technique is often employed to quantify these two opposing fluxes. An eddy‐covariance‐based system measures carbon dioxide (CO2) concentrations along with wind speed, and covariance of their fluctuations is used to calculate the net ecosystem exchange (NEE). The NEE is then partitioned into the photosynthetic and respiration components through a series of numerical operations and environmental constraints. Flux measurements in association with carbon isotopic ratios can provide a unique way to partition NEE. We have measured the concentration and isotopic ratio of CO2 and the eddy covariance‐based measurements to obtain the respiratory and photosynthetic fluxes of CO2 in a tropical forest in India. In addition, methane (CH4) concentration and its isotopic ratio have been measured to identify if trees can be considered a CH4 source in this ecosystem. Key Points: The net ecosystem exchange was measured using an eddy‐covariance technique in a forest in IndiaSeparately the greenhouse gases isotopic data were collected and used to determine the "isofluxes"Partitioning of the respiratory and the photosynthetic fluxes was carried out [ABSTRACT FROM AUTHOR]

Oxygen isotope ratios (18O/16O) of surface seawater and rainwater samples from the Indian Ocean region (10°N-60°S) during austral summer collected onboard ORV Sagar Nidhi during 2011-2013 have been measured along with salinity, sea surface temperature and relative humidity. The rainwater is isotopically lighter (by 4.6±2.7‰) compared to the equilibrium condensation of the vapour arising from the seawater at the ambient condition. The isotopic composition of the vapour at high altitude responsible for the rain formation at the sampling location is estimated from a global atmospheric water isotope model (IsoGSM2). The apparent deficit of ∼5‰ can be explained by invoking a high degree of rainout (on average, about 70% of the overhead atmospheric moisture) during transport of the source vapour to the sampling location undergoing a Rayleigh fractionation. The required rainout fraction is higher (∼80%) in the latitude belt 40°-60°S compared to the equatorial belt (∼60%). The pattern of variation in the rainout fraction with latitude is consistent with the well-known evaporation/precipitation processes in the Indian Ocean. [ABSTRACT FROM AUTHOR]

The ozone molecule possesses a unique and distinctive 17O excess (Δ17O), which can be transferred to some of the atmospheric molecules via oxidation. This isotopic signal can be used to trace oxidation reactions in the atmosphere. However, such an approach depends on a robust and quantitative understanding of the oxygen transfer mechanism, which is currently lacking for the gas-phase NO2 + O3 reaction, an important step in the nocturnal production of atmospheric nitrate. In the present study, the transfer of Δ17O from ozone to nitrate radical (NO3) during the gas-phase NO2 + O3 → NO3 + O2 reaction was investigated in a series of laboratory experiments. The isotopic composition (δ17O, δ18O) of the bulk ozone and the oxygen gas produced in the reaction was determined via isotope ratio mass spectrometry. The Δ17O transfer function for the NO2 + O3 reaction was determined to be: Δ17O(O3*) = (1.23 ± 0.19) × Δ17O(O3)bulk + (9.02 ± 0.99). The intramolecular oxygen isotope distribution of ozone was evaluated and results suggest that the excess enrichment resides predominantly on the terminal oxygen atoms of ozone. The results obtained in this study will be useful in the interpretation of high Δ17O values measured for atmospheric nitrate, thus leading to a better understanding of the natural cycling of atmospheric reactive nitrogen. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented about a study on the occurrence and impact of kala azar or visceral leishmaniasis in Bhutan.

An obituary for Indian teacher and mentor Parantapa Sen is presented.

The article focuses on the study to determine the extent of alignment between teaching and assessment practices in a problem-based learning (PBL) program offered by a medical school in Southeast Asia. The study involved concerned faculty and second year medical students who had completed three systems-based modules in the basic sciences. It was found that the examination-driven learning behavior of students was the direct impact of the type of examinations set.

Interconnects in radio frequency (RF) packages have a strong tendency to deteriorate RF performance, especially in high-frequency systems. In this paper, comparison is made between the wirebonded and embedded flip-chip packages. X-band silicon-germanium low-noise amplifiers are used to evaluate the performance of these interconnects. Measured results show that the embedded flip-chip packages have better RF performance than the wirebonded packages for X-band applications. At 9.5 GHz, the flip-chip interconnects contribute only 0.4 dB of insertion loss, while the wirebond interconnects contribute 2.2 dB of insertion loss. The flip-chip and wirebond interconnects are modeled and validated against measured results from 8 to 20 GHz. For the first time, multiple dies are put together in a single liquid crystal polymer package to compare the packaging effects, and to demonstrate the feasibility of embedding multiple dies within a single package for highly integrated solutions. [ABSTRACT FROM PUBLISHER]

Introduction: Lack of knowledge of contraceptive methods or source of supply, cost and poor access are the barriers that exist in developing countries and present study was conducted to assess the current intrauterine contraceptive device (IUCD) utilization by eligible couple in Howrah District of West Bengal. Methods: A community based cross sectional study using stratified multistage random sampling technique to obtain a sample size of 1600 using couple protection rate of West Bengal as 50%. So 12 villages and 4 urban wards were selected, with 125 sampled eligible couples in each village/ward to get 2000 eligible couples. Results: Contraceptive practice by any method was 63.3% and couple protection rate by modern method was 54.3%. IUCD use rate was 3%, oral contraceptive pill (OCP) use 25.4%, ligation 18.4%, condom 7.4%, and vasectomy 0.1%. Ever use rate of IUCD (Cu-T/Loop) was 6.3%, which increased significantly with advancement of maternal age, but was not associated with maternal literacy. Lack of motivation (43.4%), misconception (24.9%), unawareness (18.7%), unwillingness (10.9%) and religious/cultural barrier (4%) were the major reasons for underutilization of IUCD. Conclusions: IUCD acceptance is very low and different initiatives should be taken to improve it. [ABSTRACT FROM AUTHOR]

Background: Laccases and laccase-like multicopper oxidases (LMCOs) oxidize a vast array of phenolic compounds and amines, releasing water as a byproduct. Their low substrate specificity is responsible for their tremendous biotechnological interest, since they have been used for numerous applications. However, the laccases characterized so far correspond to only a small fraction of the laccase genes identified in fungal genomes. Therefore, the knowledge regarding the biochemistry and physiological role of minor laccase-like isoforms is still limited. Results: In the present work, we describe the isolation, purification and characterization of two novel LMCOs, PcLac1 and PcLac2, from Pleurotus citrinopileatus. Both LMCOs were purified with ion-exchange chromatographic methods. PcLac2 was found to oxidize a broader substrate range than PcLac1, but both LMCOs showed similar formal potentials, lower than those reported previously for laccases from white-rot fungi. Proteomic analysis of both proteins revealed their similarity with other well-characterized laccases from Pleurotus strains. Both LMCOs were applied to the oxidation of ferulic and sinapic acid, yielding oligomers with possible antioxidant activity. Conclusions: Overall, the findings of the present work can offer new insights regarding the biochemistry and variability of low-redox potential laccases of fungal origin. Low-redox potential biocatalysts could offer higher substrate selectivity than their high-redox counterparts, and thus, they could be of applied value in the field of biocatalysis. [ABSTRACT FROM AUTHOR]

Abstract The anxiolytic activity of diazepam (DZP) (0.25-1 mg/kg) was investigated in streptozotocin (STZ)-induced diabetic adult Charles Foster albino rats of either sex. Diabetes was induced by injecting STZ IP (50 mg/kg; in citrate buffer, pH 4.5). Experiments were performed 72 h later. The rats were subjected to various anxiety paradigms, including the open-field exploratory behaviour, elevated plus maze and elevated zero maze behaviours and the social interaction tests. In addition, rat brain tribulin activity was also assessed as a biochemical marker of anxiety. The results indicate that diabetic rats showed significantly more anxiogenic activity in comparison to non-diabetic rats on open-field, elevated plus maze, zero maze and social interaction tests. In diabetic rats, brain tribulin activity (MAO-A inhibitory component) was significantly increased. DZP dose dependently produced anxiolytic activity on the various behavioural parameters in nondiabetic rats. DZP (0.5 and 1 mg/kg) partially reversed the anxiogenic behaviour of STZ diabetic rats in elevated plus maze and zero maze tests. However, in open field behaviour and social interaction tests significant anxiolytic activity was observed only at a higher dose of DZP (1 mg/kg). The findings indicate that STZ induced diabetic rats exhibited augmented anxiety on various experimental paradigms and that the anxiolytic effect of diazepam was less marked in diabetic rats as compared to their euglycaemic counterparts. [ABSTRACT FROM AUTHOR]

Aim: Zinc, a trace element, is known for downregulating several proangiogenic growth factors and cytokines. However, its antiangiogenic activity is not adequately studied. The present study was aimed to evaluate the possible antiangiogenic activity of zinc via the chick chorioallantoic membrane (CAM) assay. Furthermore, the antiangiogenic activity of the combination therapy of zinc with various doses of sorafenib, a tyrosine kinase inhibitor, was evaluated. Materials and Methods: A pilot study was initially conducted so as to select suitable doses of zinc and sorafenib. The antiangiogenic activity after combining zinc 2.5 μg/embryo with sorafenib 1 and 2 μg/embryo was also evaluated. The antiangiogenic activity was quantified in terms of total length of blood vessels, number of junctions, number of branching points, and mean length of the blood vessels. Results: Zinc 2.5 μg/embryo showed significant (P < 0.05) antiangiogenic activity, as compared to the control group. However, its effect was not comparable to that of sorafenib 2 μg/embryo. The combination of zinc 2.5 μg/embryo with sorafenib 2 μg/embryo did not show an additive/synergistic effect. The combination of zinc 2.5 μg/embryo with sorafenib 1 μg/embryo produced an antiangiogenic activity which was comparable (P > 0.05) to that of sorafenib 2 μg/embryo. Conclusion: Zinc caused significant antiangiogenic activity in the CAM assay. The lack of addition/synergism in the zinc‑sorafenib combination could have been due to the variability in the dose/ratio selection. Addition of zinc to sorafenib therapy could improve treatment tolerability, reduce cost of therapy, and reduce the emergence of drug resistance. Future mechanistic studies could identify the exact pharmacodynamics of zinc as an angiogenesis inhibitor. [ABSTRACT FROM AUTHOR]

Atmospheric nitrate is preserved in Antarctic snow firn and ice. However, at low snow accumulation sites, post-depositional processes induced by sunlight obscure its interpretation. The goal of these studies (see also Paper I by Meusinger et al. ["Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry," J. Chem. Phys. 140, 244305 (2014)]) is to characterize nitrate photochemistry and improve the interpretation of the nitrate ice core record. Naturally occurring stable isotopes in nitrate (15N, 17O, and 18O) provide additional information concerning post-depositional processes. Here, we present results from studies of the wavelength-dependent isotope effects from photolysis of nitrate in a matrix of natural snow. Snow from Dome C, Antarctica was irradiated in selected wavelength regions using a Xe UV lamp and filters. The irradiated snow was sampled and analyzed for nitrate concentration and isotopic composition (δ15N, δ18O, and Δ17O). From these measurements an average photolytic isotopic fractionation of 15ε = (-15 ± 1.2)‰ was found for broadband Xe lamp photolysis. These results are due in part to excitation of the intense absorption band of nitrate around 200 nm in addition to the weaker band centered at 305 nm followed by photodissociation. An experiment with a filter blocking wave-lengths shorter than 320 nm, approximating the actinic flux spectrum at Dome C, yielded a photolytic isotopic fractionation of 15ε = (-47.9 Δ 6.8)‰, in good agreement with fractionations determined by previous studies for the East Antarctic Plateau which range from -40 to -74.3‰. We describe a new semi-empirical zero point energy shift model used to derive the absorption cross sections of 14NO3- and 15NO3- in snow at a chosen temperature. The nitrogen isotopic fractionations obtained by applying this model under the experimental temperature as well as considering the shift in width and center well reproduced the values obtained in the laboratory study. These cross sections can be used in isotopic models to reproduce the stable isotopic composition of nitrate found in Antarctic snow profiles. [ABSTRACT FROM AUTHOR]

Aim: Zinc, a trace element, is known for downregulating several proangiogenic growth factors and cytokines. However, its antiangiogenic activity is not adequately studied. The present study was aimed to evaluate the possible antiangiogenic activity of zinc via the chick chorioallantoic membrane (CAM) assay. Furthermore, the antiangiogenic activity of the combination therapy of zinc with various doses of sorafenib, a tyrosine kinase inhibitor, was evaluated.Materials and Methods: A pilot study was initially conducted so as to select suitable doses of zinc and sorafenib. The antiangiogenic activity after combining zinc 2.5 μg/embryo with sorafenib 1 and 2 μg/embryo was also evaluated. The antiangiogenic activity was quantified in terms of total length of blood vessels, number of junctions, number of branching points, and mean length of the blood vessels.Results: Zinc 2.5 μg/embryo showed significant (P < 0.05) antiangiogenic activity, as compared to the control group. However, its effect was not comparable to that of sorafenib 2 μg/embryo. The combination of zinc 2.5 μg/embryo with sorafenib 2 μg/embryo did not show an additive/synergistic effect. The combination of zinc 2.5 μg/embryo with sorafenib 1 μg/embryo produced an antiangiogenic activity which was comparable (P > 0.05) to that of sorafenib 2 μg/embryo.Conclusion: Zinc caused significant antiangiogenic activity in the CAM assay. The lack of addition/synergism in the zinc-sorafenib combination could have been due to the variability in the dose/ratio selection. Addition of zinc to sorafenib therapy could improve treatment tolerability, reduce cost of therapy, and reduce the emergence of drug resistance. Future mechanistic studies could identify the exact pharmacodynamics of zinc as an angiogenesis inhibitor. [ABSTRACT FROM AUTHOR]

Background and Purpose: Ghrelin increases growth hormone secretion, gastric acid secretion, gastric motility and hunger but decreases glucose-dependent insulin secretion and insulin sensitivity in humans. Antagonizing the ghrelin receptor has potential as a therapeutic approach in the treatment of obesity and type 2 diabetes. Therefore, the aim was to pharmacologically characterize the novel small-molecule antagonist PF-05190457 and assess translational pharmacology ex vivo.Experimental Approach: Radioligand binding in filter and scintillation proximity assay formats were used to evaluate affinity, and europium-labelled GTP to assess functional activity. Rat vagal afferent firing and calcium imaging in dispersed islets were used as native tissues underlying food intake and insulin secretion respectively.Key Results: PF-05190457 was a potent and selective inverse agonist on constitutively active ghrelin receptors and acted as a competitive antagonist of ghrelin action, with a human Kd of 3 nM requiring 4 h to achieve equilibrium. Potency of PF-05190457 was similar across different species. PF-05190457 increased intracellular calcium within dispersed islets and increased vagal afferent firing in a concentration-dependent manner with similar potency but was threefold less potent as compared with the in vitro Ki in recombinant overexpressing cells. The effect of PF-05190457 on rodent islets was comparable with glibenclamide, but glucose-dependent and additive with the insulin secretagogue glucagon-like peptide-1.Conclusions and Implications: Together, these data provide the pharmacological in vitro and ex vivo characterization of the first ghrelin receptor inverse agonist, which has advanced into clinical trials to evaluate the therapeutic potential of blocking ghrelin receptors in obesity and type 2 diabetes. [ABSTRACT FROM AUTHOR]

India has the second largest population, one of fastest growing economies and is ranked third in greenhouse gas emissions by fossil-fuel burning in the world. However, there has been little monitoring of atmospheric CO2 concentration over India to date. Here we reanalyse pioneering atmospheric CO2 observations at Cape Rama, India (CRI) during the period from February 1993 to October 2002, using three forward transport models to simulate atmospheric CO2 and separate tracers of terrestrial and oceanic fluxes, and fossil-fuel emissions. The CO2 seasonal behaviour at this site has clear signals from monsoon-driven meteorology and terrestrial ecosystem activity, which are generally captured by all three models. The quality of the agreement between the simulations and the observations varies with season, with better results obtained during the southwest monsoon months when the CRI site observes the oceanic air of mostly southern hemispheric origin. Relatively poor model-data agreements in the other seasons, when air originating from the Indian subcontinent passes over the site, arise from the inability of coarse-resolution global models to represent CRI appropriately. In addition, limited atmospheric CO2 measurements in the South Asia region only provide poor constraint on inversion fluxes. Flux signal footprint analysis of the CRI station highlights the need of extending the observation network inland and to different parts of the country for better understanding of the carbon cycle of India. [ABSTRACT FROM AUTHOR]

There is increased recognition of non-typhoidal Salmonella (NTS) as a major cause of severe febrile illness in sub-Saharan Africa. However, little is known about community-based incidence of NTS in Asia. In a multicentre, community-based prospective Salmonella surveillance study, we identified a total of six NTS cases: three in Karachi, Pakistan, one in Kolkata, India, and two in North Jakarta, Indonesia. No NTS cases were identified in Hechi, People’s Republic of China, and Hue, Viet Nam. Three cases were in children under 3 years, and one case was in a child aged 10 years and one in a child aged 15 years. Only one case was an adult (29 years). The highest incidence of NTS infection was in Karachi (7.2 culture-proven NTS cases per 100 000 person years in age group of 2–15 years). However, in comparison with sub-Saharan Africa, the NTS burden in Asia appears rather limited. [ABSTRACT FROM AUTHOR]

The neglected tropical diseases (NTDs), which affect the very poor, pose a major public health problem in the South- East Asia Region of the World Health Organization (WHO). Although more than a dozen NTDs affect the region, over the past five years four of them in particular -- leprosy, lymphatic filariasis, visceral leishmaniasis (kala-azar) and yaws -- have been targeted for elimination. These four were selected for a number of reasons. First, they affect the WHO South-East Asia Region disproportionately. For example, every year around 67% of all new leprosy cases and 60% of all new cases of visceral leishmaniasis worldwide occur in countries of the region, where as many as 850 million inhabitants are at risk of contracting lymphatic filariasis. In addition, several epidemiological, technological and historical factors that are unique to the region make each of these four diseases amenable to elimination. Safe and effective tools and interventions to achieve these targets are available and concerted efforts to scale them up, singly or in an integrated manner, are likely to lead to success. The World Health Assembly and the WHO Regional Committee, through a series of resolutions, have already expressed regional and global commitments for the elimination of these diseases as public health problems. Such action is expected to have a quick and dramatic impact on poverty reduction and to contribute to the achievement of the Millennium Development Goals. This paper reviews the policy rationale for disease control in the WHO South-East Asia Region, the progress made so far, the lessons learnt along the way, and the remaining challenges and opportunities. [ABSTRACT FROM AUTHOR]

The article discusses a study which assessed the efficacy and safety of a modified killed-whole-cell oral cholera vaccine in a population with endemic cholera in India. Several non-pregnant residents of Kolkata aged 1 year or older who participated in the double-blind trial were cluster-randomised by dwelling to receive two doses of the modified vaccine or heat-killed Escherichia coli K12 placebo orally. The study demonstrated that this modified vaccine, which is compliant with the standards of the World Health Organization (WHO), is safe, provides protection against cholera and can be used in children.

Background & objectives: Of the two reservoirs of infection of kala-azar Le., patients of kala-azar and post kala-azar dermal leishmaniasis (PKDL), PKDL provides easy access for the sandfly to pick up the parasites. In the last epidemic of 1977 in India, the importance of PKDL as a potential cause of increase in number of kala-azar cases was ignored. During recent years, we found an increase in the cases of kalaazar whereas cases of PKDL were decreasing in Bihar. We undertook this study to find out reasons for this phenomenon. Methods: These three different settings were selected to study the trends of the disease. (i) Cases of PKDL registered in the Dermatology Department of Patna Medical College Hospital (PMCH), one of the largest and oldest teaching hospital in Bihar, between 1970 and 2005; (ii) Rajendra Memorial Research Institute of Medical Sciences, Patna (RMRIMS), a research institute exclusively devoted to kala-azar (2000 and 2005); and (iii) interviews with two leading dermatologists of Patna selected by lottery on the incidence of PKDL and possible causes of its decrease, if any. The number of eases of kala-azar (visceral leishmaniasis, VL) from Bihar was studied from Malaria Departments of the Government of Bihar and Government of India, the two nodal departments dealing with the kala-azar. Results: Analysis of data from Dermatology Department of PMCH showed increase in number of cases of PKDL from two in 1970 to 12 in 1976, a year before the first epidemic of kala-azar in 1977 with 100,000 cases. Kala-azar cases decreased to 11,120 in 1982 due to control measures taken between 1977- 1979 but cases of PKDL reached 28 and kept on increasing. During 1950 to 1977, low dose and short duration regimen of sodium antimony gluconate (SAG) was mainly used in the treatment of kala-azar. Between 1977-1991 increasing incidence of unresponsiveness to SAG, led to the usage of longer duration and higher dose regimen of SAG, more use of amphotericin B (AMB) for SAG resistant cases and also as a first line drug for kala-azar and PKDL. The number of kala-azar cases started decreasing after control measures taken during 1992-1994 but cases of PKDL continued decreasing. The effect of control measures on the incidence of kala-azar was visible upto 2002, but decrease in number of PKDL cases continued. In 2005 the number of PKDL cases was 14 but number of kala-azar cases reached 21,177 in Bihar. In the interview, the two dermatologists also opined that PKDL was decreasing due to increased use of amphotericin B in the treatment of kala-azar. Trend analysis done on the data of PMCH and RMRIMS showed that PKDL will decrease in coming years and kala-azar will increase. Interpretation & conclusion: Incidence of PKDL decreased in PMCH and RMRIMS and also suggested by two dermatologists that extensive use of amphotericin B in the treatment of kala-azar might be responsible for decrease in number of cases of PKDL. [ABSTRACT FROM AUTHOR]

In the Indian state of Bihar, the sensitivities and specificities of direct agglutination tests (DAT) and rK39 test strips for the detection of Leishmania donovani infection in humans were explored and found to be generally good (92%–100%). When 172 asymptomatic individuals [16 'case-contacts' who lived in the same households as past or current, confirmed cases of visceral leishmaniasis (VL) and 156 other subjects from neighbouring households] were tested, the same 36 (21%) individuals, including all 16 'case-contacts', were found seropositive using each type of test. When followed-up after 3 months, 18 of the individuals who had been found seropositive in the baseline survey remained seropositive, and eight (44%) of these had developed symptomatic VL, with amastigotes in their splenic aspirates. Seven (44%) of the 16 'case-contacts' but only one (5%) of the other 20 subjects found seropositive at baseline went on to develop VL within 3 months. Although the strip test appeared slightly better than DAT for predicting the development of VL in the 172 subjects, either type of test may be very useful for the early detection of asymptomatic L. donovani infection and thus the identification of those at relatively high risk of developing VL. [ABSTRACT FROM AUTHOR]

This study was undertaken to develop a model to predict the incidence of typhoid in children based on adults' perception of prevalence of enteric fever in the wider community. Typhoid cases among children, aged 5-15 years, from epidemic regions in five Asian countries were confirmed with a positive Salmonella Typhi culture of the blood sample. Estimates of the prevalence of enteric fever were obtained from random samples of adults in the same study sites. Regression models were used for establishing the prediction equation. The percentages of enteric fever reported by adults and cases of typhoid incidence per 100,000, detected through blood culture were 4.7 and 24.18 for Viet Nam, 3.8 and 29.20 for China, 26.3 and 180.33 for Indonesia, 66.0 and 454.15 for India, and 52.7 and 407.18 for Pakistan respectively. An established prediction equation was: incidence of typhoid (1/100,000= -2.6946 + 7.2296 x reported prevalence of enteric fever (%) (F=31.7, p<0.01; R2=0.992). Using adults' perception of prevalence of disease as the basis for estimating its incidence in children provides a cost-effective behavioural epidemiologic method to facilitate prevention and control of the disease. [ABSTRACT FROM AUTHOR]

This study was undertaken to develop a model to predict the incidence of typhoid in children based on adults' perception of prevalence of enteric fever in the wider community. Typhoid cases among children, aged 5-15 years, from epidemic regions in five Asian countries were confirmed with a positive Salmonella Typhi culture of the blood sample. Estimates of the prevalence of enteric fever were obtained from random samples of adults in the same study sites. Regression models were used for establishing the prediction equation. The percentages of enteric fever reported by adults and cases of typhoid incidence per 100,000, detected through blood culture were 4.7 and 24.18 for Viet Nam, 3.8 and 29.20 for China, 26.3 and 180.33 for Indonesia, 66.0 and 454.15 for India, and 52.7 and 407.18 for Pakistan respectively. An established prediction equation was: incidence of typhoid (1/100,000= -2.6946 + 7.2296 x reported prevalence of enteric fever (%) (F=31.7, p<0.01; R²=0.992). Using adults' perception of prevalence of disease as the basis for estimating its incidence in children provides a cost-effective behavioural epidemiologic method to facilitate prevention and control of the disease. [ABSTRACT FROM AUTHOR]

Molecular characterization of two porcine group A rotavirus strains (HP113 and HP140), detected from eastern India, revealed a VP7 closely related to those of human G6P[14] strains, VP4 with a borderline P[13] genotype, and VP6 related to bovine and human SGI strains rather than porcine SGI and/or SGII group A rotaviruses. Both strains had NSP4 and NSP5 of porcine origin. Therefore, to our knowledge, the present study is the first report of detection of group A rotavirus strains with G6P[13] genotype specificities and provides evidence for independent segregation of the VP6- and NSP4-encoding genes in porcine group A rotaviruses. [ABSTRACT FROM AUTHOR]

A porcine Group A rotavirus strain (RU172) was detected and molecularly characterized during a surveillance study conducted for rotavirus infection in a pig farm located in a suburban area of Kolkata City, India. The G12 genotype specificity of RU172 was revealed by PCR-based genotyping assays following addition of a G12 type-specific primer (designed in our laboratory to pick up G12 isolates from field samples) and was confirmed by sequence analysis of the VP7-encoding gene. The RU172 strain exhibited maximum VP7 identities of 93.6% to 94.5% with human G12 strains at the deduced amino acid level. In spite of its G12 genotype nature, RU172 appeared to be distinct from human G12 rotaviruses and, on phylogenetic analysis, formed a separate lineage with human G12 strains. Among the other gene segments analyzed, RU172 belonged to NSP4 genotype B, had a NSP5 and VP6 of porcine origin, and shared maximum VP4 identities with porcine P[7] rotaviruses (94.3%–95.4% at the deduced amino acid level). Therefore, to the best of our knowledge, this is the first report of detection of an animal rotavirus strain with G12 genotype specificity. Detection of strains like RU172 provides vital insights into the genomic diversity of Group A rotaviruses of man and animals. [ABSTRACT FROM AUTHOR]

Background: The methanol extract of Ophirrhiza nicobarica,Alstonia macrophylla and Mallotus peltatus, ethnomedicines of Little Andaman, were investigated for antiinfective, antiinflammatory and antioxidant activities. Methods: Toxicity was determined in cells and in an animal model. Antiviral, antibacterial and antifungal activity was determined by plaque reduction, disc diffusion and agar dilution methods. The antiinflammatory and antioxidant activities were also studied. Results:O. nicobarica at 300 μg ml–1 showed anti-HSV activity while M. peltatus and A. macrophylla showed antibacterial activity at 64–1,000 μg ml–1. Both extracts showed significant dose-dependent antiinflammatory and antioxidant activity at nontoxic concentrations. Conclusion: The alkaloid, flavonoid and β-sitosterol isolated from bioactive parts had a dose-dependent therapeutic efficacy, justifying their use. Further study is required to know the mechanism of action. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]