Blue excitable green emitting Ce3+ doped CaS phosphor for w‐LEDs

CaS:Ce³⁺ is an efficient green‐emitting (535 nm) phosphor, excitable with blue light (450–470 nm) and was synthesized via a solid‐state reaction method by heating under a reducing atmosphere. The luminescent properties, photoluminescent (PL) excitation and emission of the phosphor were analyzed by spectrofluorophotometry. The excitation and emission peaks of the CaS:Ce³⁺ phosphor lay in the visible region, which made them relevant for light‐emitting diode (LED) application for the generation of white light. Judd‐Oflet parameters were calculated and revealed that green light emitted upon blue illumination. The prepared phosphor had strong blue absorption at 470 nm and a broad green emission band range from 490–590 nm with the peak at 537 nm. The characteristics of the CaS:Ce³⁺ phosphor make it suitable for use as a wavelength tunable green emitting phosphor for three band white LEDs pumped by a blue LED (470 nm). The Commission International de l'Eclairage co‐ordinates were calculated by a spectrophotometric method using the spectral energy distribution (0.304, 0.526) and confirm the green emission. The potential application of this phosphor is as a phosphor‐converted white light‐emitting diode. Copyright © 2015 John Wiley & Sons, Ltd.     

Cardiovascular risk factors in a French-Canadian population: resolution of genetic and familial environmental effects on blood pressure by using extensive information on environmental correlates.

Genetic and environmental influences on systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MBP) were examined in 371 French-Canadian families by using path analysis. Familial environment was estimated with environmental indices constructed from as many as 14 (of a pool of more than 100) correlates of blood pressure (BP). Approximately 20% of the variance in BP can be accounted for by the composite index, and the types of variables and the direction of their effects vary as a function of age and of the multivariate context. Path analysis of the family data suggests that genetic heritability is relatively high in children (from 0.49 for SBP to 0.56 for MBP) but much smaller in adults (from 0.08 for DBP to 0.18 for SBP). The proportion of variability explained by familial environment is estimated to be the same in children and adults and is much higher than reported to date (from 0.30 for SBP to 0.42 for DBP). In addition, sibships share significant nontransmitted environmental effects, and there is no evidence to suggest specific maternal effects in the aggregation of BP. Two unique findings emerge from this study. First, unlike in most earlier studies, we were able to arrive at the same parsimonious model for each of the BP variables. Second, the familial environment accounts for a substantial proportion of the variability in BP, which has been considerably underestimated in earlier studies.     

Assay for L-pipecolate oxidase activity in human liver: detection of enzyme deficiency in hyperpipecolic acidaemia.

A direct assay method is described for L-pipecolate oxidase. The assay uses NaHSO3 to trap the L-alpha-amino [3H]adipate delta-semialdehyde (AAS) formed as a direct reaction product of L-pipecolate oxidase from L-[3H]pipecolic acid. The adduct so formed was separated from the substrate on Dowex 50 (H+) column. The product was identified as [3H]AAS by amino acid analysis after breaking down the adduct by boiling under acidic conditions. The assay is simpler and more specific than fluorometric methods; it is also more sensitive, requiring at most 16 micrograms of liver peroxisome-enriched protein per assay. We have used this assay procedure to detect L-pipecolate oxidase in skin fibroblasts obtained from a control subject and from patients of hyperpipecolic acidaemia and Zellweger syndrome and found that this enzyme activity is present in the control, but absent or decreased in the patients with the peroxisomal disorders.     

Prestige,possessions, and progeny

It has been suggested by some that the acquisition of symbolic capital in terms of honor, prestige, and power translates into an accumulation of material capital in terms of tangible belongings, and that on the basis of these goods high reproductive success may be achieved. However, data on completed fertility rates over more than one generation in so-called traditional societies have been rare. Ethnographic and demographic data presented here on the pastoral Bakkarwal of northern India largely corroborate the hypothesis concerning the interdependence between the attainment of various cultural goals and differential reproduction rates and indicate that the numbers of (especially male) surviving offspring and siblings are crucial to a man’s position in society.     

The potential applications of cyanobacterial photosynthesis for clean technologies

Natural photosynthesis may be adapted to advantage in the development of clean energy technologies. Efficient biocatalysts that can be used in solar energy conversion technologies are the cyanobacteria. Photobioreactors incorporating cyanobacteria have been used to demonstrate (a) the production of hydrogen gas, (b) the assimilation of CO₂ with the production of algal biomass, (c) the excretion of ammonium, and (d) the removal of nitrate and phosphate from contaminated waters.Abbreviations Chl chlorophyll - DW dry weight - MSX L-methionine-D-L-sulphoximine - PAR photosynthetically active radiation - PU polyurethane - PV polyvinyl - PVC polyvinylchloride     

培养乳鼠心肌细胞自发性〔Ca~（2＋）〕_i瞬间变化的实验模型

使用Ｃａ￣（２＋）敏感的荧光指示剂Ｆｕｒａ－２／ＡＭ,对培养的心肌细胞测定细胞内Ｃａ￣（２＋）的瞬间变化。结果为,在一个心搏周期中,经过大约１８０ｍｓ的时间,［Ｃａ￣（２＋）］＿ｉ瞬间变化达到最大值,然后恢复到基线水平（最小值）,经历了２６０ｍｓ。测得平均［Ｃａ￣（２＋）］＿ｉ瞬间变化的最大值及最小值分别为３４６±３８ｎｍｏｌ／Ｌ和１０２±１８ｎｍｏｌ／Ｌ。血管紧张素Ⅱ１００ｎｍｏｌ／Ｌ引起［Ｃａ￣（２＋）］＿ｉ瞬间变化最大值明显增加,但对［Ｃａ￣（２＋）］＿ｉ瞬间变化的基线水平没有明显的影响。ｒｙａｎｏｄｉｎｅ３μｍｏｌ／Ｌ使［Ｃａ￣（２＋）］＿ｉ瞬间变化的幅度明显降低。ＫＣｌ５０ｍｍｏｌ／Ｌ使［Ｃａ￣（２＋）］＿ｉ瞬间变化完全停止,并明显增加［ｃａ￣（２＋）］＿ｉ的基线水平。结果提示,本实验模型可用来观察［Ｃａ￣（２＋）］＿ｉ的瞬间变化。     

A Confocal microscopic study on colony morphology and sporulation of Bacillus sp.

Hexavalent chromium Cr(VI) is one of the dominant oxidation states of chromium that exist in the environment and is highly toxic to all forms of life. In the present study, we employ a confocal laser scanning microscope (CLSM) and investigate the effect of Cr(VI) on colony morphology of a Bacillus sp. isolated from soil exposed to tannery effluent. The colonies grown at chromium concentrations, control and 100 ppm are found to be opaque and beyond 200 ppm the colonies were translucent thus exhibiting phase variation. CLSM studies on colonies grown on control plates showed significant increase in height and in biovolume as a function of time whereas, the translucent colonies showed very little change in height and biovolume corresponding to the colony growth. Exopolymeric substance (EPS) content of translucent colonies was lesser than that of opaque colonies, indicating that EPS also plays a role in the observed phenomenon of phase variation. Studies on the effect of Cr(VI) on spore formation showed that Cr(VI) concentrations up to 100 ppm favored spore formation, while concentrations beyond 100 ppm showed a steady decline in spore formation.     

Production of sapogenins (stigmasterol and hecogenin) from genetically transformed hairy root cultures of <Emphasis Type="Italic">Chlorophytum borivilianum</Emphasis> (Safed musli)

Chlorophytum borivilianum belonging to the family Liliaceae, is distributed in the pantropical regions of India and South Africa. The sapogenins (stigmasterol and hecogenin) of C. borivilianum are well known for their appetizing and aphrodisiac properties. The present study involves enhancing the sapogenin content in C. borivilianum by genetic transformations with Agrobacterium rhizogenes strains (MTCC 2364 and 532, PRT Gus). A maximum transformation frequency of 98% was obtained with Agrobacterium rhizogenes MTCC 2364 strain with rhizome explants after a co-cultivation period of 48 h. Two potential rhizoclones (2364a and 2364b) were selected for the production of stigmasterol and hecogenin. The maximum production of stigmasterol (83.952?±?0.01 mg/g) was seen in 2364b rhizoclone, whereas, the highest accumulation of hecogenin (81.52?±?0.02 mg/g) was observed in 2364a rhizoclone. The C. borivilianum hairy root cultures obtained in this study provide a continuous and sustainable production of stigmasterol and hecogenin on a commercial scale.     

Seasonal variations in the mating-related traits of Drosophila melanogaster

The Indian subcontinent shows high levels of seasonal weather variation, but the extent to which mating-related traits (mating latency, copulation duration and number of progeny produced) are being affected by such variations in Drosophila species remain poorly understood. In the present study, we analyzed the effects of seasonal change (humidity and temperature) on mating-related traits of Drosophila melanogaster by mimicking natural conditions in the laboratory. The light body color phenotype is collected in large numbers during the rainy season, while the dark phenotype is prevalent in the winter. We found that a short-term stress, in the form of reduced humidity or temperature, causes a strong climatic selection pressure, which leads to assortative mating and longer copulation duration of the dark phenotype. By contrast, the light phenotype shows higher assortative mating and longer copulation duration after short-term high humidity or high temperature stress. Higher assortative mating and increased copulation duration results in high progeny numbers which may be a cause for the high prevalence of the dark phenotype in winter and the light phenotype in the rainy season. Thus, besides plasticity, seasonal changes in mating propensity can be a potential cause of the change in the frequency of the dark and light phenotypes of D. melanogaster during different seasons.