Effect of acute concentration of zinc on the biochemical contents of brain of Labeo rohita: an FT-IR study

Heavy metal discharges to aquatic environment are of great concern due to their toxicity and accumulative behavior. Zinc is an essential trace element required for different physiological functions and plays important role in cellular metabolism. However, it becomes toxic when elevated concentrations are introduced into the environment. The aim of this work is to analyze zinc induced biochemical changes in the brain tissues of Labeo rohita fingerlings using Fourier Transformation Infrared Spectroscopy. Several important features have been observed in the zinc intoxicated brain tissues, namely, altered membrane lipid, altered protein profile and decreased glycogen content, indicating an alteration in the lipid and protein profiles leading to modification in membrane composition. Further, it is observed that the acute exposure to zinc causes some alteration in protein profile with a decrease in α-helix and an increase in random coil structures.     

Transformation of the insecticide teflubenzuron by microorganisms

Transformation of teflubenzuron, the active component in the insecticide commercialized as Nomolt, by soil microorganisms was studied. It was shown that microorganisms, belonging to Bacillus, Alcaligenes, Pseudomonas and Acinetobacter genera are capable to perform the hydrolytic cleavage of the phenylurea bridge of teflubenzuron in different positions, especially active was Bacillus brevis 625. The structure of the intermediates formed was established using TLC, HPLC, mass-spectrometry and 19F NMR techniques. It was shown that for a dose range of 53-132 microM and upon 12 days of fermentation about 30% of the teflubenzuron was modified. About 10-15% was transformed into 2,6-difluorobenzamide, 3-5% into 2,6-difluorobenzoic acid, 10-12% into 2,4-difluoro-3,5-dichloro-aniline. The late compound gave rise to formation of a condensed compound, identified as 1,2-bis(2,4-difluoro-3,5-dichlorophenyl)urea with molecular mass of 420. The results obtained indicate degradation of teflubenzuron by soil microorganisms to be a process to be mediated by microbial consortia, and starting with hydrolysis of the phenylurea bridge by several bacterial species. Subsequent further degradation of the aromatic degradation products has to be mediated by other strains known to be capable of degradation of halogenated aromatics.     

Job and industry fit: the effects of age and gender matches on career progress outcomes

Using a sample of 232 MBA alumni, we tested the impact of respondent age, gender, and their interaction on career progress outcomes (managerial level, number of promotions, and salary) and whether age‐ and gender‐type of contexts moderated these relationships. Women's salaries did not increase much with age, whereas men's salaries showed a marked increase with age. We also found a gender × job gender‐type effect on salary, such that women earned somewhat higher salaries in masculine‐typed jobs, while men earned considerably higher salaries in feminine‐typed jobs. In addition, we observed a three‐way interaction between gender, age, and age‐type of industry indicating that younger men received more promotions in old‐typed industries, while younger women received more promotions in young‐typed ones. Results are discussed in light of cognitive matching approaches and status characteristics theory. Copyright © 2004 John Wiley & Sons, Ltd.     

Interpreting spatial variation in ozone symptoms shown by cutleaf cone flower,Rudbeckia laciniata L

Visible injury caused by ozone is recorded every year in native plant species growing in Great Smoky Mountains National Park (USA). One of the most sensitive species, cutleaf coneflower (Rudbeckia laciniata L.), shows great variation in symptoms between and within populations but the causes of this variation and its ecological significance are currently unknown. This paper presents data relating to genetic variation, ozone concentrations, stomatal conductance and light (PAR) within populations. The data show that populations differ in genetic diversity, one consisting of only three genets while another was very diverse. In the former population, symptoms varied greatly within a single genet, pointing to a large micro-environmental influence. Measurements of ozone, stomatal conductance and PAR within plant canopies suggest that variation in symptom expression is unlikely to be due to differences in ozone flux and more likely to be due to variation in light. The variation in visible symptoms raises the question of what bioindicators actually indicate, and it suggests that symptoms should be interpreted with great caution until the underlying causes of that variation are fully understood.     

Trisomic pregnancies have normal human chorionic gonadotropin bioactivity

Sera from women carrying either chromosomally normal or aneuploid fetuses in the first half of pregnancy were assayed for human chorionic gonadotropin (hCG) bioactivity in order to determine whether differences might provide the basis for a useful antenatal screen for aneuploidy. A mouse uterine weight assay was used to assess hCG bioactivity in sera from 35 patients undergoing chorionic villus sampling (12 normal pregnancies and 23 trisomic pregnancies) and in sera from 18 patients undergoing elective second-trimester abortion (12 presumed normal pregnancies, 3 trisomic pregnancies, and 3 pregnancies with neural tube defects). The hCG bioactivity to immunoactivity (B:I) ratio of normal pregnancies progressively decreased from 7.7±1.3 at 4–5 menstrual weeks, to 4.7±0.4 at 9–12 menstrual weeks, to 3.3±0.5 at 16–20 menstrual weeks. There were no significant differences in the B:I ratios between normal and aneuploid pregnancies in either the first-trimester (4.7±0.4 versus 5.2±0.3) or the second-trimester samples (3.3±0.5 versus 2.6±0.3), despite significantly greater hCG concentrations in the trisomic pregnancies. We conclude that while aneuploid pregnancies display dysfunctional regulation of hCG expression, the bioactivity of their hCG is normal and does not appear to form the basis for a useful screen for aneuploidy.     

Deposition Velocities of SO2 and O3 over Agricultural and Forest Ecosystems

The results of field studies that measured the flux anddeposition velocity of SO₂ and O₃ are reported. Three of the studies were over agricultural crops (pasture, corn, and soybean), and two were over forest (a deciduous forest and a mixed coniferous–deciduous forest). In all cases the deposition velocity for SO₂ was higher than that for O₃. Diurnal cycles of SO₂ deposition velocity were similar in shape, but not magnitude for all surfaces; however those for O₃ showed some difference between forest sites where the peak was in the morning, and the agricultural sites where the peak occurred at mid-day. Seasonal cycles of SO₂ were affected by deposition to surfaces when leaves were not active, yet surface conductance is significant, but not for O₃ where stomatal uptake is the primary pathway for deposition.(On assignment to the National Exposure Research Lab., US EPA) (e-mail:     

The national incinerator testing and evaluation program two-stage incinerator combustion tests

In this paper the summary results of tests conducted at the P.E.I. energy-from-waste facility, a two-stage incinerator, are presented. Extensive data on refuse feed, ash, emissions and operating conditions will provide the most significant body of information yet available for energy from waste facilities.     

Albatross species demonstrate regional differences in North Pacific marine contamination.

Recent concern about negative effects on human health from elevated organochlorine and mercury concentrations in marine foods has highlighted the need to understand temporal and spatial patterns of marine pollution. Seabirds, long-lived pelagic predators with wide foraging ranges, can be used as indicators of regional contaminant patterns across large temporal and spatial scales. Here we evaluate contaminant levels, carbon and nitrogen stable isotope ratios, and satellite telemetry data from two sympatrically breeding North Pacific albatross species to demonstrate that (1) organochlorine and mercury contaminant levels are significantly higher in the California Current compared to levels in the high-latitude North Pacific and (2) levels of organochlorine contaminants in the North Pacific are increasing over time. Black-footed Albatrosses (Phoebastria nigripes) had 370-460% higher organochlorine (polychlorinated biphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs]) and mercury body burdens than a closely related species, the Laysan Albatross (P. immutabilis), primarily due to regional segregation of their North Pacific foraging areas. PCBs (the sum of the individual PCB congeners analyzed) and DDE concentrations in both albatross species were 130-360% higher than concentrations measured a decade ago. Our results demonstrate dramatically high and increasing contaminant concentrations in the eastern North Pacific Ocean, a finding relevant to other marine predators, including humans.     

First-trimester aneuploidy screening using serum human chorionic gonadotropin (hCG), free ahCG,and progesterone

Immunochemical serum assays for human chorionic gonadotropin (hCG), the free ohCG subunit, and progesterone (P) were considered separately and in combination for their ability to screen for chromosomally abnormal pregnancies in the first trimester. Maternal serum was collected from 141 women undergoing chorionic villus sampling at 9–12 menstrual weeks. Trisomy 21 pregnancies had significantly higher hCG levels, while trisomy 18 and 13 pregnancies had markedly lower hCG and progesterone levels than those of chromosomally normal pregnancies. However, the discrimination of normal from aneuploid pregnancies was poor with either hCG alone, progesterone alone, or free ahCG alone. Much improved discrimination was obtained by combining hCG, free ahCG, and P into an aneuploidy index [(P/hCG)(free ahCG/hCG)]. This index distinguished 9 out of 17 (53 per cent) of the trisomy 21 pregnancies, while only misidentifying 5 out of 112 (4.5 per cent) of the normal pregnancies. The aneuploidy index thus appears promising as a first-trimester biochemical screen for aneuploid pregnancies.