Rhythms in larval release of the sublittoral crab Neopanope sayi and the supralittoral crab Sesarma cinereum (Decapoda: Brachyura)

Ovigerous females of the subtidal xanthid crab Neopanope sayi (Smith) and the high intertidal grapsid crab Sesarma cinereum (Bosc) were collected during the summers of 1986 and 1987 in the Beaufort, North Carolina (USA), area and brought into the laboratory, where rhythms in larval release were monitored. When crabs with late-stage embryos were put under a 14 h light:10 h dark cycle in an otherwise constant-environment room, an apparent tidal rhythm in release of larvae was observed for both species, with N. sayi releasing near the time of day and night high tides, and S. cinereum releasing around the time of night high tides. The time of sunset relative to high tide was a complicating factor, since larval release for both species was often concentrated around sunset when evening high tides fell several hours before sunset. When a group of N. sayi and S. cinereum were brought into the laboratory and placed under constant lowlevel light for 5 d, the release rhythm of the population persisted, thus implying that the rhythm is endogenous. Larval release near the time of high tide and often at night is common among brachyurans living in tidal areas, regardless of specific adult habitat, suggesting a common functional advantage. Possibilities include transport of larvae from areas where predation and the likelihood of stranding and exposure to low-salinity waters are high, as well as a reduced probability of predation on adult females. Results of the present study suggest that the importance of release after darkness may increase with increasing tidal height of the adult.     

Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes

The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account.     

Mercury exposure through diet in pregnant women and women of childbearing age

The study examined the stage of clean-up of the Port Lavaca bay sites in Texas, which were polluted during the early 1990's by effluent containing mercury (Hg) from a chloralkali plant. In addition to Hg intoxication through environmental contaminations, human exposure through dietary fish and other seafoods occurred. Bacteria converts inorganic Hg to alkyl organic compounds and subsequently the metal crosses the blood brain barrier thus exerting adverse effects on the fetal developing nervous system. In order to conduct a survey of dietary Hg exposure, blood was collected from pregnant women and those of childbearing age at routine clinic visits at each of three centers in South Texas cities (Galveston, Texas City, Port Lavaca/Victoria, TX). A questionnaire sought dietary and lifestyle information including consumption, sources of fish and other seafoods. A significant number of subjects (119 out of 175, 68%) ate fish caught locally. The blood Hg concentrations (µg?L^?1) range varied with the location of the study centers: City of Galveston 2.6–62; Texas City 2.8–111.8; and the Port Lavaca areas 3.02–126.7. The concentrations of blood Hg was directly proportional to the number of fish meals consumed for each species considered. Mean blood Hg concentrations for no fish meals per week were: Port Lavaca 4.5 (N?=?3), Galveston 4.3 (N?=?3), Texas City 3.5 (N?=?10). For >3 fish meals per week, the mean blood Hg concentrations were: Port Lavaca, 48.0 (N?=?53), Galveston 29.1 (N?=?35), Texas City, 36.1 (N?=?31). Data show that residues of Hg were still present in 1994 despite the clean-up efforts.     

Rehabilitation of the chernoistochinskii drinking water system,Nizhnii Tagil,Russia

The U.S. Environmental Protection Agency (EPA) performed a reservoir diagnosis and developed low-cost recommendations to improve drinking water quality for the city of Nizhnii Tagil, Russia. Despite widespread regional pollution, water quality within the drinking water supply source can be summarized as generally good. Sampling and analysis efforts did not reveal appreciable amounts of hazardous chemicals or metals. The major water quality problem stems from an abundance of blue-green algae during the summer months, causing drinking water taste and odor problems and filter clogging at the water treatment plant. City water treatment officials also frequently experience difficulties with maintaining an effective disinfection residual in the distribution system because it spans more than 30 kilometers in length. Regrowth of microorganisms in the distribution system often causes coliform bacteria counts to exceed standards. The implementation of a watershed protection and management program, and the installation of a new disinfection system, to purify drinking water and to reduce bacterial growth in the distribution system should improve drinking water quality for the city residents.     

Gulf War agents trigger discrete transcriptional changes in human neuronal cells

Reports on Gulf War illness (GWI) implicated the use of the pesticide permethrin (PER), and the insect repellent N,N-diethyl-m-toluamide (DEET), in its etiology, as well as pyridostigmine bromide (PB), which was given as a prophylactic treatment against nerve agent exposure. Using Affymetrix microarrays the genomic response of human neuronal SHSY-5Y cells to 10 days of exposure to these agents was characterized and profiles of gene modulation unique to each treatment were demonstrated. In particular, a significantly greater impact of PER was observed compared to the other treatments. The Ingenuity Pathway Analysis knowledgebase was used to analyze the genomic datasets and attribute functional consequences to the effects of related genes, which were significantly up- or down-regulated in response to different treatments. Canonical pathways shown to be significantly modulated at the genomic level in response to exposure included cellular mechanisms, which might contribute to the clinical presentation in GWI patients and thus be targeted for further investigation as potential targets for therapeutic intervention.     

Population structure of yellowfin tuna (Thunnus albacares) in the western Pacific Ocean, inferred from microsatellite loci

Five polymorphic microsatellite loci were examined in 1391 yellowfin tuna (Thunnus albacares) from eight regions of the western (Coral Sea, eastern Australia, Fiji, Indonesia, Philippines and Solomon Islands) and eastern (California and Mexico ) Pacific Ocean. Across all samples, numbers of alleles per locus ranged from 7 to 30 (mean: 17.0), and observed heterozygosities per locus ranged from 0.223 to 0.955 (mean: 0.593). Temporal collections were available for three areas: no significant temporal heterogeneity was observed for the Coral Sea (1991/1992 and 1995/1996 collections) or eastern Australia (1994/1995, 1995/1996, 1996/1997 and 1997/1998), but there was slight but significant heterogeneity at one locus (cmrTa-161) between the two Philippines collections (1994/1995 and 1996/1997). Genotypes generally showed a good fit to Hardy-Weinberg expectations within populations; only cmrTa-208 in the pooled Coral Sea population gave a significant deviation after Bonferroni correction for 40 tests, with a small but significant excess of homozygotes. Four loci showed no evidence of population differentiation following contingency Chi-squared and F_ST analyses. The fifth locus, cmrTa-161, showed small but significant differentiation (F_ST=0.002, P<0.001). This heterogeneity was largely a result of the Philippines 1994/1995 and Fiji collections; there was no correlation with geographic distance. The average F_ST across all five loci was very low (F_ST=0.002), but it was significant (P<0.001). It is unclear whether this low but significant differentiation reflects noise in the dataset, perhaps arising from experimental error, or real population differentiation. The finding of very limited population heterogeneity accords with most of the earlier allozyme and mitochondrial DNA studies of yellowfin tuna in the Pacific Ocean.     

Transverse approach between real world concentrations of SO2, NO2, BTEX, aldehyde emissions and corrosion in the Grand Mare tunnel

With regard to automotive traffic, a tunnel-type semi enclosed atmosphere is characterized by a higher concentration of gaseous pollutants than on urban traffic roads and highlights the gaseous effluent species having an impact on material degradation. Therefore, a transverse approach between air quality and its consequences upon the longevity of materials is necessary, implying better knowledge of tunnel atmosphere and a better understanding of material degradation inside a tunnel for operating administration. Gaseous pollutant measurements carried out in a road tunnel in Rouen (Normandy) give the real world traffic concentrations of experimental exposure conditions. The sampling campaigns, achieved in summer and winter include SO₂, NO₂, BTEX and aldehyde analyses. Effluent profiles in the upward and downward tubes have been established. The current work shows that SO₂, NO₂, formaldehyde, acetaldehyde, propanal and butanal must be considered in the degradation process of materials in a stuffy environment. As regards NO₂, its concentration depends on the modification of the automotive fleet. The total aldehyde concentrations indicate no particular trend between the two bores. Formaldehyde, acetaldehyde, propanal, butanal and acrolein species are the most abundant species emitted by vehicles and represent 90% to 95% of the total aldehyde emissions.     

Studies on the seasonal changes of phosphorus in the marine environments off Cochin

Studies were conducted to evaluate the changes of phosphorus in marine water and sediments of seven stations in the coastal areas off Cochin. Samples were collected on a monthly basis from January 2001 to December 2001. Results revealed higher levels of P in marine water samples collected during October-December 2001. The marine water P ranged from 0 to 0.38 ppm throughout the year. Speciation of P in marine sediment revealed that the Al bound P was maximum compared to Fe, Ca and organic bound P. Loosely bound and aluminium bound P was maximum during October-December especially in 10 and 20 m depth stations off Narakkal. Fe bound P was found to be least in June and September and highest during January-April. Low levels of Ca bound P were detected in samples collected during January-March and inorganic P was maximum in June and September. Organic bound P was maximum in 10 m depth stations and also during June and September. Phosphate fractions varied with locations and exhibited seasonal fluctuations.     

The transformation of outdoor ammonium nitrate aerosols in the indoor environment

Recent studies associate particulate air pollution with adverse health effects; however, the exposure to indoor particles of outdoor origin is not well characterized, particularly for individual chemical species. We conducted a field study in an unoccupied, single-story residence in Clovis, California to provide data and analyses to address issues important for assessing exposure. We used real-time particle monitors both outdoors and indoors to quantify nitrate, sulfate, and carbon particulate matter of particle size 2.5 μm or less in diameter (PM-2.5). The results show that measured indoor ammonium nitrate concentrations were significantly lower than would be expected based solely on penetration and deposition losses. The additional reduction can be attributed to the transformation indoors of ammonium nitrate into ammonia and nitric acid gases, which are subsequently lost by deposition and sorption to indoor surfaces. A mass balance model that accounts for the kinetics of ammonium nitrate evaporation was able to reproduce measured indoor ammonium nitrate and nitric acid concentrations, resulting in a fitted value of the deposition velocity for nitric acid of 0.56 cm s⁻¹. The results indicate that indoor exposure to outdoor ammonium nitrate in Central Valley of California are small, and suggest that exposure assessments based on total particle mass measured outdoors may obscure the actual causal relationships for indoor exposure to particles of outdoor origin.     

Heavy metals in soils: distribution, relationship with soil characteristics and radionuclides and multivariate assessment of contamination sources

The study is dealing with the distribution and the origin of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in soils from a priori non-polluted areas. Positive correlations with organic matter and clay content but not with pH have been observed for most of elements analyzed in this study. Correlations of some metals (Cr, Pb and Zn) and radionuclides (238U and 137Cs) observed for analyzed soils could be explained by their common affinity for clay minerals. Enrichment factor (EF) analysis and cluster analysis (CA) highlighted the lithogenic origin of Cr, Cu, Mn, Ni, Pb and Zn and pointed out the primary input of Cd from anthropogenic sources. It also revealed the need for detailed geochemical surveys in the future in order to decrease the uncertainty of discrimination between lithogenic and anthropogenic origin of metals of interest.