An ultraluminous X-ray source powered by an accreting neutron star.

The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from 10(39) to 10(41) ergs per second. Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end of the range (more than 10(40) ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 × 10(39) ergs per second. The pulsating source is spatially coincident with a variable source that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 × 10(40) ergs per second. This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects.

Measurement of the damping of the nuclear shell effect in the doubly magic 208Pb region.

The damping of the nuclear shell effect with excitation energy has been measured through an analysis of the neutron spectra following the triton transfer in the (7)Li induced reaction on (205)Tl. The measured neutron spectra demonstrate the expected large shell correction energy for the nuclei in the vicinity of doubly magic (208)Pb and a small value around (184)W. A quantitative extraction of the allowed values of the damping parameter γ, along with those for the asymptotic nuclear level density parameter ã, has been made for the first time.

Electromagnetic transition from the 4+ to 2+ resonance in 8Be measured via the radiative capture in 4He + 4He.

An earlier measurement on the 4+ to 2+ radiative transition in 8Be provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. This Letter reports a more elaborate and precise measurement for this transition, via the radiative capture in the 4He + 4He reaction, improving the accuracy by about a factor of 3. Ab initio calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and ab initio calculations.

Eclampsia-scenario in a hospital--a ten years study.

This cross sectional record based institutional study was conducted in the Department of Obstetrics & Gynaecology, Burdwan Medical College, Burdwan over ten years (1999-2008) aiming analysis of eclamptic mothers for evaluation of maternal and perinatal outcome with different anticonvulsant medications. Total 5991 pregnant mothers with eclampsia admitted in the inpatient department of the tertiary care teaching hospital were recruited for the study, irrespective of their previous antenatal check up history. Subjects with known seizure disorders were excluded from the study. The subjects were managed according to standard regimens (Menon, Ph-sodium, diazepam & magnesium sulphate) and results were documented in standardised format. Case fatality rate, mean induction delivery time & birth-weight, perinatal mortality rates were recorded. Study reveals that the incidence of eclampsia <20 years was 6.97% and majority (5.41%) came from rural areas. Eclampsia was noted primarily in primigravida (7.43%) and unbooked (6.41%) mothers. Ante partum eclampsia predominated (64%) and incidence of caesarean section was 22.25%.The overall case fatality rate was 6.05% and eclampsia contributed 27.85% of all maternal deaths during the last two years of the study period. The overall incidence of low birth weight baby was 26.96% and perinatal mortality was 30.33% (1411/4651).The incidence of perinatal mortality and low birth weight babies are lower in the last 4 years when compared to earlier studies. Proper socio-demographic assessment of pregnancy with eclampsia, planned delivery, shorter induction delivery interval, good control of convulsion by magnesium sulphate, intensive intranatal monitoring causes less maternal and perinatal morbidity and mortality.

Arsenate exposure affects amino acids, mineral nutrient status and antioxidants in rice (Oryza sativa L.) genotypes.

Simulated pot experiments were conducted on four rice (Oryza sativa L.) genotypes (Triguna, IR-36, PNR-519, and IET-4786) to examine the effects of As(V) on amino acids and mineral nutrient status in grain along with antioxidant response to arsenic exposure. Rice genotypes responded differentially to As(V) exposure in terms of amino acids and antioxidant profiles. Total amino acid content in grains of all rice genotypes was positively correlated with arsenic accumulation. While, most of the essential amino acids increased in all cultivars except IR-36, glutamic acid and glycine increased in IET-4786 and PNR-519. The level of nonprotein thiols (NPTs) and the activities of superoxide dismutase (SOD; EC 1.15.1.1), glutathione reductase (GR; EC 1.6.4.2) and ascorbate peroxidase (APX; EC 1.11.1.11) increased in all rice cultivars except IET-4786. A significant genotypic variation was also observed in specific arsenic uptake (SAU; mg kg(-1)dw), which was in the order of Triguna (134) > IR-36 (71) > PNR-519 (53) > IET-4786 (29). Further, application of As(V) at lower doses (4 and 8 mg L(-1) As) enhanced the accumulation of selenium (Se) and other nutrients (Fe, P, Zn, and S), however, higher dose (12 mg L(-1) As) limits the nutrient uptake in rice. In conclusion, low As accumulating genotype, IET-4786, which also had significantly induced level of essential amino acids, seems suitable for cultivation in moderately As contaminated soil and would be safe for human consumption.

Quasi-periodic X-ray brightness fluctuations in an accreting millisecond pulsar.

The relativistic plasma flows onto neutron stars that are accreting material from stellar companions can be used to probe strong-field gravity as well as the physical conditions in the supra-nuclear-density interiors of neutron stars. Plasma inhomogeneities orbiting a few kilometres above the stars are observable as X-ray brightness fluctuations on the millisecond dynamical timescale of the flows. Two frequencies in the kilohertz range dominate these fluctuations: the twin kilohertz quasi-periodic oscillations (kHz QPOs). Competing models for the origins of these oscillations (based on orbital motions) all predict that they should be related to the stellar spin frequency, but tests have been difficult because the spins were not unambiguously known. Here we report the detection of kHz QPOs from a pulsar whose spin frequency is known. Our measurements establish a clear link between kHz QPOs and stellar spin, but one not predicted by any current model. A new approach to understanding kHz QPOs is now required. We suggest that a resonance between the spin and general relativistic orbital and epicyclic frequencies could provide the observed relation between QPOs and spin.

Detection of bovine herpesvirus 1 sequences in yaks (Bos grunniens) with keratoconjunctivitis, using a highly sensitive nested polymerase chain reaction.

Thirty-seven yaks (Bos grunniens) with keratoconjunctivitis and 22 healthy yaks were used to investigate the role of bovine herpesvirus 1 (BoHV-1) in keratoconjunctivitis in yaks. Nucleic acid sequences of BoHV-1 glycoproteins B and E were detected in conjunctival swabs from all yaks with keratoconjunctivitis using a nested polymerase chain reaction (PCR). In 21 yaks, BoHV-1 sequences were detected along with Moraxella bovis (M. bovis) and Neisseria spp. The amplified BoHV-1 sequences were identical, and no nucleotide variation was observed when compared with a BoHV-1 reference strain using single-strand conformation polymorphism analysis of the amplified DNA sequences. Interestingly, BoHV-1 sequences could not be detected in samples from healthy yaks. However, conjunctival swabs from two healthy yaks (9.09%) yielded M. bovis and Neisseria spp. Samples from 35 yaks with keratoconjunctivitis showed positive reactions in an avidin biotin enzyme-linked immunosorbent assay for BoHV-1 antibodies; all the healthy yaks were seronegative. This is the first report of a possible association of BoHV-1 with keratoconjunctivitis in yaks.

The use of fish community structure as a measure of ecological degradation: a case study in two tropical rivers of India.

Fish community structure and water chemistry of two tropical rivers of West Bengal, an eastern province of India, were studied for two annual cycles (January 2003-December 2004) and a higher degree of pollution was found in one river (the Churni) than in the other river (the Jalangi). This was reflected in the water quality as well as in fish community structure of the rivers. We observed that 63.6% of fish species appeared to have been eliminated from the polluted Churni river since 1983 in 20 years. For the protection of fish biodiversity and enhancement of fish production, a rational management program should be implemented for the Churni river.

Bioturbation-induced phosphorous release from an insoluble phosphate source.

The influence of bioturbation caused by common carp fry in 5 L jars (5 L each) in the laboratory and in 150 L outdoor vats in increasing the fertilizer value of phosphate rock was evaluated. Soluble reactive phosphate (SRP) was determined to quantify the effects of bioturbation, fish excrements and soil. The level of SRP was always lowest in the control series. Introduction of common carp fry resulted in a net increase of 0.09-0.10 mg L(-1) of SRP attributable to the effect of fish excrement. Bioturbation caused by common carp resulted in a 64.8-90% influx of phosphate from bottom soil in the presence of phosphate rock but only about 6.3-7.2% in the absence of phosphate rock. The bioturbation that occurred in these treatments resulted in a significant release of phosphorous into the overlying water from the apatite source. The results confirm the benefits of the application of environmentally friendly phosphate rock in fish farming ponds at low cost.

Hyperhydricity in apple: ultrastructural and physiological aspects.

We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants. Morphological, anatomical and ultrastructural differences between healthy leaf tissues obtained from greenhouse-grown plants and healthy and hyperhydric leaves obtained from shoots raised from nodal shoot explants in a bioreactor were investigated by electron microscopy and confocal laser scanning microscopy. Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle. Stomata were malformed. The leaf lamina appeared thickened and was characterized by poor differentiation between the palisade and spongy mesophyll tissue. Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves. Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves, indicating that hyperhydricity was associated with oxidative stress. Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves.

A pilot survey on hand washing among some communities of West Bengal.

A cross-sectional observational study was carried out between April to May 2006 by interview method and observation technique with the objective to know the knowledge regarding hand washing in the community and it was done in the slum and nonslum urban areas and also one rural area. The result shows that in urban slum area 98% washed their hands with soap after defecation; Only 36%, 16% and 2% washed their hands with soap before meal, before serving food and before cooking respectively. However, it was observed that 69% used soap and water for hand washing after cleaning the child's faeces. In rural area 71% used soap and water after defecation while 26% used mud or ash. Only 13%, 1%, 1% and 5% used soap and water before meal, before serving food, before cooking and after cleaning the child's faeces. 82.35% of respondents in non slum area and 89% of respondents in rural area considered that diarrhoea and dysentery could be prevented by hand washing while they did not give importance to hand washing in prevention of diarrhoea over other methods like cleanliness, boiling and purification of water. ARI was much higher (25.72%) in rural area followed by slum area (13.77%) and non-slum area (3.87%). Out of 30 observations among 302 interview made on hand-washing only first step i.e. palm washing (transient rubbing the palm with soap) was followed by all the participants observed. Time taken for such hand-washing was only around five seconds (ideal 15-30 seconds) in urban slum and rural areas while in non slum area it varied between 7-10 seconds on an average. No one followed any other steps of hand-washing, recommended by IFH.

Application of bioreactor system for large-scale production of Eleutherococcus sessiliflorus somatic embryos in an air-lift bioreactor and production of eleutherosides.

Embryogenic callus was induced from leaf explants of Eleutherococcus sessiliflorus cultured on Murashige and Skoog (MS) basal medium supplemented with 1 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D), while no plant growth regulators were needed for embryo maturation. The addition of 1 mg l(-1) 2,4-D was needed to maintain the embryogenic culture by preventing embryo maturation. Optimal embryo germination and plantlet development was achieved on MS medium with 4 mg l(-1) gibberellic acid (GA(3)). Low-strength MS medium (1/2 and 1/3 strength) was more effective than full-strength MS for the production of normal plantlets with well-developed shoots and roots. The plants were successfully transferred to soil. Embryogenic callus was used to establish a suspension culture for subsequent production of somatic embryos in bioreactor. By inoculating 10 g of embryogenic cells (fresh weight) into a 3l balloon type bubble bioreactor (BTBB) containing 2l MS medium without plant growth regulators, 121.8 g mature somatic embryos at different developmental stages were harvested and could be separated by filtration. Cotyledonary somatic embryos were germinated, and these converted into plantlets following transfer to a 3l BTBB containing 2l MS medium with 4 mg l(-1) GA3. HPLC analysis revealed that the total eleutherosides were significantly higher in leaves of field grown plants as compared to different stages of somatic embryo. However, the content of eleutheroside B was highest in germinated embryos. Germinated embryos also had higher contents of eleutheroside E and eleutheroside E1 as compared to other developmental stages. This result indicates that an efficient protocol for the mass production of E. sessiliflorus biomass can be achieved by bioreactor culture of somatic embryos and can be used as a source of medicinal raw materials.

Haemorrhagic protein of Russell's viper venom with fibrinolytic and esterolytic activities.

A haemorrhagic toxin specifically active on skin and muscle at the site of introduction in mice has been purified from Vipera russelli russelli (Indian subspecies of Russell's viper) venom by CM-Sephadex C-50 ion exchange chromatography and size exclusion (SE)-HPLC. This toxic protein also has strong fibrinolytic and arginine esterolytic activities. The purified preparation was a single polypeptide chain of molecular weight 73,000, as revealed by SDS-PAGE and SE-HPLC under native and denatured conditions. It has been named as VRR-73. Atomic absorption spectrometry indicated the existence of Mg(2+) in a mol per mol ratio. Antiserum was effective in neutralizing haemorrhage when administered immediately following VRR-73 but was ineffective in inhibiting fibrinolytic and esterolytic activities. On the other hand phenylmethyl sulphonyl fluoride and EDTA inhibited fibrinolysis and esterolysis but did not affect haemorrhage. Thermal denaturation of VRR-73, after exposure at 100 degrees C for 10 min, led to inactivation of all of its activities. Fibrinolytic and esterolytic activities, but not the haemorrhagic activity, were slowly regained after cooling at 25 degrees C. Thus the two pathological activities of VRR-73 appear to be associated with two different regions of the molecule.

Purification and partial characterization of a haemorrhagin (VRH-1) from Vipera russelli russelli venom.

A haemorrhagic toxin (VRH-1) has been purified to homogeneity from Vipera russelli russelli venom by subjecting it to chromatography twice successively on CM-Sephadex C-50. It is a protein of mol. wt 22,000 and contains one mole of Mg2+. Intradermal administration of this haemorrhagin in mice resulted in severe lung haemorrhage but produced little haemorrhage in skin. This apparent organ preference led us to develop a new haemorrhage assay method utilizing dye diffusion from lung in vitro. Proteolytic activity of VRH-1 was demonstrated using dimethylcasein as substrate following quantitation by reaction with trinitrobenzoyl sulfonic acid. Both haemorrhagic and proteolytic activities of VRH-1 were inhibited by serine protease inhibitors like phenylmethyl sulfonyl fluoride and chymostatin, but metal chelators had no effect. Lung haemorrhage is unlikely to be a direct reflection of a high local concentration of VRH-1. The administration of supernatant generated by incubation of chopped liver from untreated mouse and VRH-1 (in subhaemorrhagic dose) results in severe lung haemorrhage. This raises the possibility that VRH-1 leads to the formation of intermediate(s) which causes the haemorrhage.

Lethal and haemorrhagic activity of Russell's Viper venom--neutralization by polyvalent, monovalent and toxoid antiserum.

Lethal and haemorrhagic activity of Russell's Viper venom was compared against polyvalent bivalent commercial antiserum and monovalent antiserum raised in rabbit. Formaldehyde-detoxified venom offered 7-fold protection against lethal activity and 12.5-fold against haemorrhagic activity of the venom. Whole venom and formaldehyde-detoxified venom along with Freund's complete adjuvant, injected in rabbits produced high titre antiserum. Amongst all the six antiserum tested, the monovalent antiserum raised in rabbit, showed maximum precipitating bands in immunogeldiffusion and immunoelectrophoresis. The toxoid-antiserum offered maximum protection against the venom-induced lethality and the monovalent antiserum offered maximum protection against haemorrhagic activity.

Purification and characterization of an organ specific haemorrhagic toxin from Vipera russelli russelli (Russell's viper) venom.

A haemorrhagic toxin (VRR-12) from Vipera russelli russelli (Russell's viper) venom has been purified by ion-exchange chromatography on CM-Sephadex C-50 followed by size-exclusion HPLC to electrophoretically homogeneous state. It is a 12 kDa single polypeptide having 1 mole of Zn+2 ion. This toxin induces intense intestinal haemorrhage and to a lesser extent skeletal muscle haemorrhage in mice. It does not show detectable proteolytic and esterolytic activity with selected substrates under specified conditions, haemolytic and phospholipase activity. When VRR-12, preincubated with bivalent antiserum against Saw-scaled and Russell's viper venom or EDTA was injected, haemorrhagic activity was not reduced, on the other hand preincubation with phenylmethyl sulphonyl fluoride reduced the activity markedly. Biodistribution studies with 125I VRR-12 show that haemorrhagic manifestation by this toxin is not a direct function of the fraction of the totally administered toxin distributed to that tissue.

Dynamics of water in synthetic saponite clays: effect of trivalent ion substitution.

Saponite clay belongs to the phyllosilicate family and is comprised of layers of Si(IV) tetrahedra and Al(III) or Mg(II) octahedra with definite interlayer spacing. In these systems, the trivalent ion substitutions in the tetrahedral layers lead to negative charge on the layers. Here we report the dynamics of water contained in [Si(6.97)Al(1.03)][Ni(6.00)]O(20)(OH)(4)[Na(1.03)]·28H(2)O (SAP-1) and [Si(7.13)Fe(0.86)][Ni(6.00)]O(20)(OH)(4)[Na(0.86)]·14H(2)O (SAP-2) saponite clays in the temperature range 200-310 K as studied by quasielastic neutron scattering technique. Particularly the effect of the ion substitution towards the dynamics of water is addressed here. Data analysis is carried out using the relaxing cage model. The existence of distribution in relaxation times indicated that the water molecules in saponite clay have a different local environment which leads to complex diffusion behavior. It is found that water exists in a supercooled state in the temperature range up to 235 K. However, some of the water molecules are found to be immobile in the temperature range 240-285 K. The fraction of immobile water decreases with increase in temperature. At higher temperatures, some of the water molecules in the hydration shells or those near the surface start participating in the diffusion process and at 293 K, almost all water molecules contribute to the dynamics. Diffusivity of water in both SAP-1 and SAP-2 are found to be lower in comparison to the bulk, and within the two samples of saponite clay diffusivity in SAP-1 is found to be lower compared to SAP-2; this has been explained on the basis of the charge on the tetrahedral layers and the charge balancing cations in the interlayer spacing.

Assessing cold chain status in a metro city of India: an intervention study.

BACKGROUND: Cold chain maintenance is an essential activity to maintain the potency of vaccines and to prevent adverse events following immunization. One baseline study highlighted the unsatisfactory cold chain status in city of Kolkata in India. OBJECTIVES: To assess the changes which occurred in the cold chain status after the intervention undertaken to improve the status and also to assess the awareness of the cold chain handlers regarding cold chain maintenance. METHODS: Intervention consisted of reorganization of cold chain points and training of health manpower in Kolkata Municipal area regarding immunization and cold chain following the guidelines as laid by Govt of India. Reevaluation of cold chain status was done at 20 institutions selected by stratified systematic random sampling after the intervention. The results were compared with baseline survey. RESULTS: Significant improvement had been observed in correct placing of cold chain equipment, maintenance of stock security, orderly placing of ice packs, diluents and vaccines inside the equipment, temperature recording and maintenance. But awareness and skill of cold chain handlers regarding basics of cold chain maintenance was not satisfactory. CONCLUSIONS: The success of intervention included significant improvement of cold chain status including creation of a designated cold chain handler. The gaps lay in non-availability of non-electrical cold chain equipment and separate cold chain room, policy makers should stress. Cold chain handlers need reorientation training regarding heat & cold sensitive vaccines, preventive maintenance and correct contingency plan.

Cadmium-induced biochemical responses of Vallisneria spiralis.

The following study was carried out to investigate the cadmium (Cd) accumulating potential of Vallisneria. After subjecting plants to different concentrations of Cd, it was observed that plants are able to accumulate ample amount of metal in their roots (5,542 microg g(-1) dw) and leaves (4,368 microg g(-1) dw) in a concentration- and duration-dependent manner. Thus, it is evident that the accumulation in roots was 1.3 times higher than the shoots. It was also noted that with increasing Cd accumulation, roots of the plant appeared darker in color and harder in texture. In response to metal exposure, amount of low molecular weight antioxidants such as cysteine and nonprotein thiols (NP-SH) and activity of enzymes such as APX and GPX were significantly enhanced at lower concentrations of Cd, followed by decline at higher doses. It was also observed that in exposed plants, activity of APX enzyme was higher in roots (ca. 3 times) as compared to leaves. However, chlorophyll and protein content was found to decline significantly in a dose-dependent manner. Results suggested that due to its high accumulation potential, Vallisneria may be effectively grown in water bodies moderately contaminated with Cd.

Lead bioaccumulation potential of an aquatic macrophyte Najas indica are related to antioxidant system.

Plants of Najas indica bioaccumulated significantly higher amounts of Pb (3554 microg g(-1) dw) when, exposed to varying concentrations of Pb(NO(3))(2).This also led to increased malondialdehyde (MDA), electrical conductivity (EC) and H(2)O(2) content. In response to this, the activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR) were elevated along with the induction of various molecular antioxidants including GSH, cysteine, ascorbic acid and proline. Further, Pb exposed plants showed significantly increased cysteine synthase and glutathione-S-transferase activity. Visible symptoms of toxicity were evident at 50 microM after 4d showing chlorosis and fragmentation of leaves with mucilaginous discharge. It seems that bioaccumulated Pb is efficiently tolerated by Najas plants through activation of antioxidant system and thiolic pathways which was evident by the increased biomass up to 10 microM Pb. Therefore, it appears that due to metal tolerance characteristics with high concentration factor these plants can find use in phytoremediation of aquatic system highly contaminated by Pb.