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There is evidence that symptoms of maldigestion or malabsorption in autistic individuals are related to changes in the indigenous microbiota. Analysis of colonic bacteria has revealed microbial dysbiosis in children with autism; however, characteristics of the duodenal microbiome are not well described. In the present study the microbiome of the duodenal mucosa of subjects with autism was evaluated for dysbiosis, bacteria overgrowth, and microbiota associated with carbohydrate digestion. The relationship between the duodenal microbiome and disaccharidase activity was analyzed in biopsies from 21 autistic subjects and 19 children without autism.Microbiota composition was determined by 16S ribosomal RNA gene sequencing, and disaccharidase activity via biochemical assays.Although subjects with autism had a higher frequency of constipation (P 0.005), there was no difference in disaccharidase activity between groups. In addition, no differences in microbiome diversity (species richness and evenness) were observed. Bacteria belonging to the genus Burkholderia were more abundant in subjects with autism, whereas members of the genus Neisseria were less abundant. At the species level, a relative decrease in abundance of 2 Bacteroides species and Escherichia coli was found in autistic individuals. There was a positive correlation between the abundance of Clostridium species, and disaccharidase activity, in autistic individuals.There are a variety of changes at the genus and species level in duodenal microbiota in children with autism that could be influenced by carbohydrate malabsorption. These observations could be affected by variations in individual diets, but also may represent a more pervasive dysbiosis that results in metabolites that affect the behavior of autistic children.

The extent to which microorganisms impair wound healing is an ongoing controversy in the management of chronic wounds. Because the high diversity and extreme variability of the microbiota between individual chronic wounds lead to inconsistent findings in small cohort studies, evaluation of a large number of chronic wounds using identical sequencing and bioinformatics methods is necessary for clinicians to be able to select appropriate empiric therapies. In this study, we utilized 16S rDNA pyrosequencing to analyze the composition of the bacterial communities present in samples obtained from patients with chronic diabetic foot ulcers (N = 910), venous leg ulcers (N = 916), decubitus ulcers (N = 767), and nonhealing surgical wounds (N = 370). The wound samples contained a high proportion of Staphylococcus and Pseudomonas species in 63 and 25% of all wounds, respectively; however, a high prevalence of anaerobic bacteria and bacteria traditionally considered commensalistic was also observed. Our results suggest that neither patient demographics nor wound type influenced the bacterial composition of the chronic wound microbiome. Collectively, these findings indicate that empiric antibiotic selection need not be based on nor altered for wound type. Furthermore, the results provide a much clearer understanding of chronic wound microbiota in general; clinical application of this new knowledge over time may help in its translation to improved wound healing outcomes.

Background The role of viruses in chronic rhinosinusitis (CRS) is poorly understood. In part, this is secondary to difficulty in isolating viruses. Although traditional detection methods for respiratory viruses have had little clinical utility, modern viral screening techniques that use molecular sequencing are now both rapid and feasible, which makes analysis of the paranasal sinus microbiome more accessible. Objective To detect respiratory viruses in the paranasal sinuses of patients with CRS and of healthy controls as well as to correlate clinical and radiographic measures of CRS with viral presence. Methods In this prospective study, 13 patients with CRS with nasal polyposis (CRSwNP) and 8 patients without nasal polyposis (CRSsNP) were enrolled and compared with 14 healthy controls. Samples were obtained from the paranasal sinuses and were screened for viral DNA with polymerase chain reaction—based sequencing techniques. Typical symptoms of CRS, the Sinonasal Questionnaire, and objective measures, including the modified Lund-Mackay and modified Lund-Kennedy scores were obtained. Results Eighty percent of the positive screens (4/5) were found in patients with CRSsNP, whereas 20% of the positive tests (1/5) were in the CRSwNP group, and none of the controls tested positive (p = 0.0029). Coronavirus was the most common virus detected. Sinonasal Questionnaire scores of the patients with CRS who tested positive for viruses were higher but not statistically different than those without a positive screen (p = 0.31). Radiographic and endoscopic measures of disease were not significantly different in the setting of a positive viral screen (p = 0.12 and 0.11 respectively). Conclusion Although traditionally difficult, advances in molecular sequencing enhance detection of viruses in the sinonasal tract. In this study, respiratory viruses were more commonly isolated from patients with CRS compared with healthy controls. Moreover, viral infection may play a greater role in symptom exacerbation in CRSsNP than in CRSwNP. These findings warrant further investigation into the role of the viral microbiome in CRS.

Background: Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized. Objectives: The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards. Methods: PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing. Results: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind. Conclusions: Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs. Citation: McEachran AD, Blackwell BR, Hanson JD, Wooten KJ, Mayer GD, Cox SB, Smith PN. 2015. Antibiotics, bacteria, and antibiotic resistance genes: aerial transport from cattle feed yards via particulate matter. Environ Health Perspect 123:337–343; http://dx.doi.org/10.1289/ehp.1408555

Identification of microbial assemblages predominant under natural extreme climatic events will aid in our understanding of the resilience and resistance of microbial communities to climate change. From November 2010 to August 2011, the Southern High Plains (SHP) of Texas, USA, received only 39.6 mm of precipitation (vs. the historical average of 373 mm) and experienced the three hottest months (June–August 2011) since record keeping began in 1911. The objective of this study was to characterize soil bacterial (16 S rRNA gene) and fungal (internal transcribed spacer 1–4, ITS1-ITS4) species distribution and diversity via pyrosequencing during the peak of the drought/heat wave in July 2011 and when the Drought Index and temperatures were lower in March 2012. Samples were collected from two different soil types (loam and sandy loam) under two different dryland cropping histories (monoculture vs. rotation). Fungal Diversity Indexes were significantly higher after the drought/heat wave while Bacterial Indexes were similar. Bacterial phyla distribution in July 2011 was characterized by lower relative abundance of Acidobacteriaand Verrucomicrobia, and greater relative abundance of Proteobacteria, Chloroflexi, Actinobacteria and Nitrospirae than March 2012 samples. Further grouping of pyrosequencing data revealed approximately equal relative proportions of Gram positive (G+) and Gram negative (G−) bacteria in July 2011, while G− bacteria predominated in March 2012. Fungal class Dothideomycetes was approximately two times greater in July 2011 than in March 2012, while the class Sordariomycetes and a group of unidentified OTUs from Ascomycota increased from July 2011 to March 2012. Microbial community composition was less influenced by management history than by the difference in climatic conditions between the sampling times. Correspondence analysis identified assemblages of fungal and bacterial taxa associated with greater enzyme activities (EAs) of C, N, or P cycling found during the drought/heat wave. Microbial assemblages associated with arylsulfatase activity (key to S cycling), which increased after the drought/heat wave, were identified (Streptomyces parvisporogenes, Terrimonas ferruginea and Syntrophobacter sp.) regardless of the soil and management history. The distinct microbial composition found in July 2011 may represent assemblages essential to maintaining ecosystem function during extreme drought and intense heat waves in semiarid agroecosystems.

Plastics are used widely as agricultural mulches to suppress weeds and retain soil moisture. Disposal of conventional plastic mulches requires physical removal for disposal in a landfill or incineration. Biodegradable plastic mulches that could be tilled into the soil at the end of a growing season represent an attractive alternative to conventional plastic mulches. In this study, three commercially available mulches labeled as "biodegradable" and one experimental, potentially biodegradable mulch were used during a tomato growing season, and then buried in field soil at three locations for approximately 6 months, as would occur typically in an agricultural setting. Degradation after 6 months in soil was minimal for all but the cellulosic mulch. After removal of mulches from soil, fungi were isolated from the mulch surfaces and tested for their ability to colonize and degrade the same mulches in pure culture. The majority of culturable soil fungi that colonized biodegradable mulches were within the family Trichocomaceae (which includes beneficial, pathogenic, and mycotoxigenic species of Aspergillus and Penicillium). These isolates were phylogenetically similar to fungi previously reported to degrade both conventional and biodegradable plastics. Under pure culture conditions, only a subset of fungal isolates achieved detectable mulch degradation. No isolate substantially degraded any mulch. Additionally, DNA was extracted from bulk soil surrounding buried mulches and ribosomal DNA was used to assess the soil microbial community. Soil microbial community structure was significantly affected by geographical location, but not by mulch treatments.

Population models have emerged as a powerful tool to better understand the ecological effects of toxicant exposure. Currently, most ecotoxicology population models are deterministic and fail to account for natural variability in biological processes and uncertainty in parameter estimates. We developed, parameterized, and analyzed a Daphnia population model with three different levels of demographic stochasticity to examine how a pesticide, pendimethalin, affects population dynamics. We conducted laboratory studies to generate the data used for the modeling process. The simplest model only included parameter uncertainty and variability. The second model included daily stochastic fecundities. The third model included stochastic fecundities and stochastic mortalities. Of the three models, the second model with stochastic fecundity best described our laboratory test system. All three models were used to test hypotheses about how pesticides would affect population dynamics. We found that pendimethalin either decreased the baseline juvenile survivorship rate or the carrying capacity. We could differentiate the two test effects with our system. Our findings demonstrate how stochastic population models may provide insight into pesticide exposure.

Absorption, distribution, and biotransformation are 3 critical aspects affecting toxicant action in animals. In the present study, B6C3F1 mice (Mus musculus) were exposed for 28 d to contaminated feed that contained 1 of 5 different hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) concentrations: 0 mg/kg, 0.5 mg/kg, 5 mg/kg, 50 mg/kg, and 500 mg/kg. The authors quantified RDX and its reductive transformation products hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in the stomach, intestine, plasma, liver, and brain of these mice. Average RDX concentrations followed a dose-dependent pattern for all matrices tested. No controls had concentrations above limits of detection. Average RDX concentrations in tissues of exposed mice ranged from 11.1 ng/mL to 182 ng/mL, 25.6 ng/g to 3319 ng/g, 123 ng/g to 233 ng/g, 144 ng/g to 35 900 ng/g, and 51.1 ng/g to 2697 ng/g in the plasma, brain, liver, stomach, and intestine, respectively. A considerable amount of RDX was present in the brain, especially in the highest-exposure group. This is consistent with the widely observed central nervous system effects caused by γ-aminobutyric acid inhibition associated with RDX exposure. N-nitroso metabolites of RDX were also present in tested tissues in a dose-dependent pattern. Average MNX concentrations in the stomachs of mice exposed to RDX ranged from nondetectable in control exposures to 490 ng/g in the highest-exposure groups. In the brain, MNX accumulated at a maximum average concentration of 165.1 ng/g, suggesting the potential formation of MNX from RDX within the brain. At higher exposures, DNX and TNX were present in the stomach, plasma, and brain of mice. The presence of RDX metabolites at notable amounts in different tissues suggests that RDX can transform into its N-nitroso metabolites in vivo by an undefined mechanism. Environ Toxicol Chem 2013;32:1295–1303. © 2013 SETAC

Introduction and Overview Ronald J. Kendall Environmental Toxicology of Munitions-Related Compounds: Nitroaromatics and Nitramines Todd A. Anderson Agriculture: Pesticides, Plants, and Biofuels Spencer R. Mortensen, Thomas E. Nickson, and George P. Cobb Influence of Pesticides and Environmental Contaminants on Emerging Diseases of Wildlife Steven M. Presley, Galen P. Austin, C. Brad Dabbert Impacts of Contaminants and Pesticides on Biodiversity and Ecosystem Structure and Function Thomas E. Lacher, Jr., John Bickham, Claude Gascon, Rhys Green, Robin D. Moore, and Miguel Mora Impacts of Anthropogenic CO2 and Climate Change on the Biology of Terrestrial and Marine Systems Lee Hannah Statistical Models in Wildlife Toxicology Stephen B. Cox Global Perspectives on Wildlife Toxicology: Emerging Issues Philip N. Smith, Mohamad Afzal, Redha Al-Hasan, Henk Bouwman, Michael H. Depledge, Muralidharan Subramanian, Venugopal Dhananjayan, Cristina Fossi, Malsha Kitulagodage, Henrik Kylin, Robin Law, Letizia Marsili, Todd O'Hara, Paul Story, Celine Godard-Codding, Luisa Eugenia Castillo, and Manuel Spinola Ecological Risk Assessment and Emerging Issues in Wildlife Toxicology Christopher J. Salice Looking Forward: The Global Future of Wildlife Toxicology Ronald J. Kendall, Todd A. Anderson, George P. Cobb, Stephen B. Cox, Lee Hannah, Thomas E. Lacher, Jr., Steven M. Presley, Christopher J. Salice, and Philip N. Smith

Background: The “office nurse” or clinical associate (registered nurse [RN], licensed practical nurse[LPN], or medical assistant [MA]) is a key member of the family medicine care team, but little is known about the influence of their level of training on team performance. Methods: The performance of the clinical dyad (clinician and associate) was studied in relation to the level of training of the nurse. The dyad9s performance was measured by the performance indicators of diabetes scores, patient satisfaction, and productivity. Results: Dyads with a RN scored higher in meeting all 5 of the diabetes quality indicators (27.8%) than those with a LPN (19.3%) or an MA (14.7%). For patient satisfaction, the RN dyads also scored higher than the other dyad groups (positive responses: RN, 96.8%; LPN, 95.5%; MA, 94.6%). Productivity was the same in all groups. Better diabetes performance was seen in those practices with fewer competing demands: nonrural versus rural (22.2% vs 15.1%, respectively), and those not doing obstetrics versus those doing obstetrics (20.3% vs 15.1%, respectively), and for physicians versus associate providers (18.8% vs 15.1%, respectively). Higher patient satisfaction was observed in those dyads who were nonrural verus rural (96.6 vs 94.1%), among those doing obstetrics (96.0% vs 94.9%), and in physicians verus associate providers (95.7% vs 93.2%). The number of years working with the same clinician was twice as high for RNs (6.63) and LPNs (6.57) than for MAs (3.29). Conclusions: A higher level of education of the clinical associate seems to confer skills that enhance the care team9s management of chronic illness such as diabetes. This could potentially decrease the practice burden on other team members while facilitating the team9s objectives in meeting quality indicators.

Many children with autism spectrum disorders (ASDs) suffer from gastrointestinal problems such as diarrhoea, constipation and abdominal pain. This has stimulated investigations into possible abnormalities of intestinal microbiota in autistic patients. Therefore, we designed this study to identify differences (and/or similarities) in the microbiota of children with autism (without gastrointestinal dysfunction: n = 23; with gastrointestinal dysfunction: n = 28) and their neurotypical siblings (n = 53) who share a similar environment using bacterial tag-encoded FLX amplicon pyrosequencing. Regardless of the diagnosis and sociodemographic characteristics, overall, Firmicutes (70%), Bacteroidetes (20%) and Proteobacteria (4%) were the most dominant phyla in samples. Results did not indicate clinically meaningful differences between groups. The data do not support the hypothesis that the gastrointestinal microbiota of children with ASD plays a role in the symptomatology of ASD. Other explanations for the gastrointestinal dysfunction in this population should be considered including elevated anxiety and self-restricted diets.

The synthetic growth-promoting hormones trenbolone and melengestrol acetate have been detected in the environment near beef cattle feedlots and are reportedly transported via wind-borne particulate matter. Therefore, movement of synthetic hormones from beef cattle feedlots to water bodies via particulate matter is possible. Our objective was to evaluate potential effects of 17α-trenbolone (17α-TB), melengestrol acetate (MGA), and combinations of both on growth, development, and survival of Xenopus laevis larvae. On post-hatch day 2 (stage 33/34), X. laevis larvae were exposed to three nominal concentrations of 17α-TB (10, 100, and 500 ng/L), MGA (1, 10, and 100 ng/L), a combination of both (1/10, 10/100, and 100/500 ng/L MGA/17α-TB), frog embryo teratogenesis assay-Xenopus medium, or a solvent control. Significant increases in all X. laevis growth metrics were observed among larvae in the 1 ng/L MGA + 10 ng/L 17α-TB and 10 ng/L MGA + 100 ng/L 17α-TB treatments. Stage of development was increased among larvae in the 1 ng/L MGA + 10 ng/L 17α-TB treatment group and significantly decreased among those in the 500 ng/L 17α-TB treatment. Total body mass and snout-vent length of X. laevis larvae were significantly reduced in the 100 ng/L MGA and 100 ng/L MGA + 500 ng/L 17α-TB treatment groups. Larvae exposed to 500 ng/L 17α-TB had decreased total body mass, snout-vent length, and total length. In general, growth measurements decreased with increasing concentration of MGA, 17α-TB, or a combination of both. Survival among all treatments was not significantly different from controls. Amphibians exposed to MGA and 17α-TB in the environment may experience alterations in growth and development.

Land use mediated habitat changes are associated with global amphibian declines. Intensive farming occurs in the Southern High Plains, USA, causing habitat loss through cultivation and subsequent sedimentation of playa wetlands. We determined the effects of sedimentation and other factors (e.g., hydroperiod, vegetative cover, wetland volume loss due to sediment, and playa density) hypothesized to have an influence on amphibian species richness. We sampled amphibian species richness in 40 playas with cropland watersheds and 40 playas with native grassland watersheds. Hydroperiod was the primary factor influencing amphibian species richness; playas with longer hydroperiods had higher cumulative amphibian species richness than playas with shorter hydroperiods. Percent vegetative cover was also positively related to species richness. Sedimentation of playas in the Southern High Plains reduces hydroperiod length and the number of playas available to breeding amphibians, two factors influencing richness. Shortened hydroperiods negatively affect reproductive success of amphibian species with long larval periods [e.g., barred tiger salamander (Ambystoma tigrinum mavortium), American bullfrog (Rana catesbeiana)], limiting amphibian species richness. Efforts to conserve amphibian species richness in playas should focus on reducing sediment and ensuring availability of sufficient vegetative cover.

This study integrated physical, chemical, and molecular techniques to assess relationships between soil bacterial community structures and the quantity and quality of soil organic carbon (SOC) at the soil microenvironment scale (e.g., within different aggregate size-fractions). To accomplish this goal, soil samples (0–5 cm) were collected from the Texas High Plains region under a variety of dryland and irrigated cropping systems. The soil was separated into macroaggregates, microaggregates, and silt + clay fractions that were analyzed for (1) bacterial diversity via pyrosequencing of the 16s rRNA gene and (2) SOC quantity and quality using a combustion method and mid-infrared diffuse reflectance spectroscopy (mid-IR), respectively. Results from pyrosequencing showed that each soil microenvironment supported a distinct bacterial community. Similarly, mid-IR data revealed distinct spectral features indicating that these fractions were also distinguished by organic and mineral composition. Macroaggregates showed relatively high abundance of Actinobacteria (excluding order Rubrobacteriales) and α-Proteobacteria and contained the most SOC. Microaggregates showed high relative abundance of Rubrobacteriales and the least amount of SOC. Predominance within the soil microenvironment and correlations along the mid-IR spectra were different between members of the order Rubrobacteriales compared with all other members of the Actinobacteria phyla, suggesting they have different ecological niches. Mid-IR results revealed microaggregates had greater absorbance in the 1370–1450 cm−1 region for phenolic and alkyl groups (possibly recalcitrant C). Silt + clay fractions were distinguished by Gemmatimonadetes and OP10 phyla, which positively correlated with spectral absorption in the1250–1150 cm−1 range (indicating both degradable and recalcitrant C forms). In contrast to general diversity index measurements, distributions of the more rare bacterial phyla (phyla representing

Titanium dioxide nanomaterials (nano-TiO2) exhibit stronger photochemical oxidation/reduction capacity compared with their bulk counterparts, but the effectiveness of nano-TiO2 interaction with ultraviolet (UV) light strongly depends on particle size. In this study, the dependence of nano-TiO2 toxicity on particle size and interaction with UV light were investigated. Toxicity tests with Xenopus laevis included eight concentrations of nano-TiO2 in the presence of either white light or UVA (315–400 nm). We quantified viability and growth of Xenopus laevis. Results showed that, regardless of UV light exposure, increasing TiO2 concentration decreased X. laevis survival (p

Objective: This large, level a, retrospective cohort study set out to compare healing outcomes in three large cohorts of wound patients managed universally for bioburden: standard of care group, who were prescribed systemic antibiotics on the basis of empiric and traditional culture-based methodologies; treatment group 1, who were prescribed an improved selection of systemic antibiotics based on the results of molecular diagnostics; treatment group 2 who received personalised topical therapeutics (including antibiotics) based on the results of molecular diagnostics. Method: apart from the differences in diagnostic methods and antibiotic treatments described above, all three cohorts were subjected to the same biofilm-based wound care protocol, which included evaluation of the host and bioburden, frequent sharp debridement, use of wound dressings and comprehensive standard care (reperfusion therapy, nutritional support, offoading, compression and management of comorbidities). Results: In all, 1378 patients were recruited into the study. In the standard of care group 48.5% of patients (244/503) healed completely during the 7-month study period. This increased to 62.4% (298/479) in treatment group 1 and 90.4% (358/396) in treatment group 2. Cox proportional hazards analysis revealed the time to complete closure decreased by 26% in treatment group 1 (p200% better odds of healing at any given time point compared with the other cohorts. Conclusion: Implementation of personalised topical therapeutics guided by molecular diagnosis resulted in statistically and clinically significant improvements in outcome. The integration of molecular diagnostics and personalised medicine provides a directed and targeted approach to wound care. Conflict of interest: SED and RDW are owners of PathoGenius laboratories, a clinical diagnostic laboratory. SED and RDW are owners of Research and Testing laboratory, which develops molecular diagnostics. CJ and JK are clinical advisors for PathoGenius. CJ and JK are owners of Southeastern medical Compounding, Savannah, Ga and Southeastern medical Technologies, Savannah, Ga.

Dengue is the most commonly transmitted arthropod-borne virus in the world with 50–100 million cases annually. Within the United States, dengue is a reemerging infectious disease of concern and near the U.S.–Mexico border, up to 75% of the population of some Texas communities have had exposure to dengue. Understanding dengue disease dynamics is critical to predicting and understanding the disease. These dynamics depend upon diverse factors such as socioeconomic conditions, the local environment, and vector biology. Here, we study dengue by examining the role of temperature in driving vector dynamics. To do this, we created a Susceptible, Exposed, Infectious, Recovered host and Susceptible, Exposed, Infectious vector (SEIR/SEI) model. The SEIR/SEI model was then used in conjunction with an Aedes albopictus population model to create a vector-based disease model. The vector-based diseased model was then forced by temperature. Approved for public release; distribution is unlimited.

Expression of the enzyme CYP1A1 in the skin of marine mammals has been shown by multiple studies to indicate exposure to organic pollutants in a dose-dependent manner. A new large-scale monitoring study investigated whether analysis of dermal CYP1A1 expression and organic pollutants in sperm whales (Physeter macrocephalus) could reveal oceanwide geographical trends in chemical exposure [EHP 119(3):337–343; Godard-Codding et al]. This is the first known study to assess broad geographic trends in CYP1A1 expression, stable carbon and nitrogen isotopes, and organic pollutant burdens in a threatened whale species. The authors used immunochemistry to analyze CYP1A1 expression in skin and blubber samples collected from 234 sperm whales from five Pacific Ocean regions. Variation in the whales’ trophic level (position in the food chain) was examined by using mass spectrometry to measure nitrogen isotopes in skin samples; enrichment of an animal’s tissue nitrogen is known to occur as the animal eats higher on the food chain. The general latitude frequented by the whales—a reflection of where the whales were likely to have been exposed to pollution—was determined by analyzing carbon isotope ratios. The whales exhibited significant regional differences in CYP1A1 expression. Expression was highest among whales from the Galapagos Islands, a United Nations World Heritage marine reserve, and lowest among whales from sites farthest away from continents. Differences in the whales’ age, sex, and diet did not appear to explain regional differences but could not be ruled out unequivocally. This study did not show a significant correlation between CYP1A1 expression in skin cells and actual pollutant burden in blubber, as measured by analyzing eight sex-specific pooled samples for burdens of polycyclic aromatic hydrocarbons, hexachlorobenzene, polychlorinated biphenyls, and the pesticide DDT, then comparing them with CYP1A1 immunohistochemistry scores estimated for the pooled samples. However, the small size of the individual biopsies allowed under standards for humane biopsying of marine mammals prevented detailed chemical analyses and limited the power to detect significant associations. Also, the biopsies were limited to the outer blubber layer, which is less metabolically active than deeper tissue. Studies in bottlenose dolphins have shown that CYP1A1 expression in the skin is more strongly related to pollutants measured in deeper blubber than in blubber closer to the skin surface; whether such stratification happens in other cetaceans requires further study. The study succeeded at identifying regional differences in CYP1A1 expression, providing a baseline for this known biomarker of exposure to organic pollutants. Future studies that profile CYP1A1 expression in cetacean skin biopsies oceanwide are warranted to explore the global distribution of biochemically relevant levels of these chemicals.

Objective To compare healing outcomes at a wound healing centre both before and after the introduction of molecular pathogen diagnostics. Method An IT consultant was recruited to analyse the medical records of patients at a wound healing centre, comparing patient groups from 2007 and 2009 — before and after the introduction of comprehensive molecular pathogen diagnostic methods. Results Before the implementation of molecular diagnostics, 244/503 patients (48.5%) healed completely, while after implementation 298/479 patients (62.4%) healed. Furthermore, based on survival analysis and after controlling for potential confounding factors, time to healing was significantly shorter in 2009 than 2007 (pConclusion The results of modern molecular pathogen diagnostic applications allow comprehensive evaluation of the microbial bioburden in chronic wounds. This comprehensive diagnostic in turn has led to a more precise and targeted therapeutic approach to wound care. With the comprehensive nature of molecular diagnostics future advances in topical patient specific therapeutics are now possible. Declaration of interest SED and RDW are owners of Pathogenius diagnostics, a clinical diagnostic facility. SED is director of Research and Testing Laboratory, which develops molecular diagnostics. Analysis was performed and approved by outside consultant SBC, who indicates no conflict of interest.

During the last four years, significant effort has been devoted to understanding the effects that Hurricanes Katrina and Rita had on contaminant distribution and redistribution in New Orleans, Louisiana, USA, and the surrounding Gulf Coast area. Elevated concentrations were found for inorganic contaminants (including As, Fe, Pb, and V), several organic pollutants (polycyclic aromatic hydrocarbons, pesticides, and volatiles) and high concentration of bioaerosols, particularly Aeromonas and Vibrio. Data from different research groups confirm that some contaminant concentrations are elevated, that existing concentrations are similar to historical data, and that contaminants such as Pb and As may pose human health risks. Two data sets have been compiled in this article to serve as the foundation for preliminary risk assessments within greater New Orleans. Research from the present study suggests that children in highly contaminated areas of New Orleans may experience Pb exposure from soil ranging from 1.37 microg/d to 102 microg/d. These data are critical in the evaluation of children's health.

Continuous measurement of plant canopy temperature is useful in both research and production agriculture settings. Industrial-quality infrared thermometers which are often used for measurement of canopy temperatures, while reliable, are not always cost effective. For this study a relatively low-cost, consumer-quality infrared thermometer was incorporated into a wireless monitoring system intended for use in plant physiological studies and in agricultural production settings. The field performance of this low-cost wireless system was compared to that of a typical research system based on an industrial-quality infrared thermometer. Performance was evaluated in terms of: reliability of data acquisition, quality of seasonal temperature measurements, seasonal stability of the consumer-quality infrared sensor, and the equivalence of temperatures measured by the consumer-quality and industrial-quality temperature sensors. Results indicate that for many common uses of plant temperature data, the two sensors provide functionally equivalent results. The cost savings and ease of use associated with the low-cost wireless temperature monitoring system present advantages over the higher-cost industrial-quality sensors which may make them a viable alternative in many agricultural settings.

Aedes albopictus has been the fastest spreading invasive animal species in the world from the mid-1980s until the mid-2000s. In areas it infests, it disrupts native mosquito ecology and can potentially vector up to 21 viruses. To better understand the population dynamics of this species, we created a temperature dependent population model. A stage-structured model was chosen to allow each life-stage to have different temperature dependent mortality and development rates, and each stage was modeled with an ordinary differential equation. Model parameters and distributions were based upon literature values. Initially, a basic model was constructed. This model then had parameters that were forced based upon daily average temperatures. Several criteria were used to evaluate the model, including a comparison to field data from Lubbock, TX. In a stochastic version of the model, a 95% confidence limit contained 70.7% of the field data points. Based upon these results, we feel reasonably confident that we have captured the role of temperature in driving the population dynamics of Ae. albopictus.

Immediately following hurricane Katrina concern was raised over the environmental impact of floodwaters on the city of New Orleans, especially in regard to human health. Several studies were conducted to determine the actual contaminant distribution throughout the city and surrounding wetlands by analyzing soil, sediment, and water for a variety of contaminants including organics, inorganics, and biologics. Preliminary investigations by The Institute of Environmental and Human Health at Texas Tech University concluded that soils and sediments contained pesticides, semi-volatiles, and metals, specifically arsenic, iron, and lead, at concentrations that could pose a significant risk to human health. Additional studies on New Orleans floodwaters revealed similar constituents as well as compounds commonly found in gasoline. More recently, it has been revealed that lead (Pb), arsenic, and vanadium are found intermittently throughout the city at concentrations greater than the human health soil screening levels (HHSSLs) of 400, 22 (non-cancer endpoint) and 390 μg/g, respectively. Of these, Pb appears to present the greatest exposure hazard to humans as a result of its extensive distribution in city soils. In this study, we spatially evaluated Pb concentrations across greater New Orleans surface soils. We established 128 sampling sites throughout New Orleans at approximately half-mile intervals. A soil sample was collected at each site and analyzed for Pb by ICP-AES. Soils from 19 (15%) of the sites had Pb concentrations exceeding the HHSSL threshold of 400 μg/g. It was determined that the highest concentrations of Pb were found in the south and west portions of the city. Pb concentrations found throughout New Orleans in this study were then incorporated into a geographic information system to create a spatial distribution model that can be further used to predict Pb exposure to humans in the city.

Few studies have examined the potential long-term effects of high concentrations of hexahydro-1,3,5-trinitro-1,3,5-triaxine (RDX) on bacterial communities in soil. In the present study, a sandy loam soil and a silt loam soil (high and low bioavailability, respectively) were artificially contaminated with RDX (0, 50, 500, 1,500, 5,000, 10,000, and 15,000 mg/kg soil). Bacterial communities from each treatment were monitored over 63 d to characterize the effects of RDX exposure on bacterial activity, biomass, functional diversity (Biolog microtiter plates), and structural diversity (denaturing gradient gel electrophoresis of 16S rDNA). Bacterial communities native to the high bioavailability soil were inherently different than bacterial communities native to the silt loam soil, not only in terms of bacterial activity and biomass, but also in terms of bacterial community functional and structural diversity. Soil RDX contamination was correlated with decreased bacterial biomass in the silt loam soil treatments and with decreased bacterial activity in the sandy loam soil treatments on day 7. Soil RDX contamination did not cause a significant shift in the functional diversity of the bacterial communities native to the silt loam soil, but was correlated with a shift in identities of substrates used by bacterial communities native to the sandy loam soil on day 7. Bacterial community structure was insensitive to the gradient of RDX concentrations at the beginning of the incubation. However, the identities of carbon substrates used by bacterial communities in both soil types were affected by long-term incubation with RDX. Environ. Toxicol. Chem. 2010;29:38–44. © 2009 SETAC

Anthropogenic activities have accelerated the rate of global loss of biodiversity, making it more important than ever to understand the structure of biodiversity hotspots. One current focus is the relationship between species richness and aboveground biomass (AGB) in a variety of ecosystems. Nonetheless, species diversity, evenness, rarity, or dominance represent other critical attributes of biodiversity and may have associations with AGB that are markedly different than that of species richness. Using data from large trees in four environmentally similar sites in the Luquillo Experimental Forest of Puerto Rico, we determined the shape and strength of relationships between each of five measures of biodiversity (i.e., species richness, Simpson’s diversity, Simpson’s evenness, rarity, and dominance) and AGB. We quantified these measures of biodiversity using either proportional biomass or proportional abundance as weighting factors. Three of the four sites had a unimodal relationship between species richness and AGB, with only the most mature site evincing a positive, linear relationship. The differences between the mature site and the other sites, as well as the differences between our richness‐AGB relationships and those found at other forest sites, highlight the crucial role that prior land use and severe storms have on this forest community. Although the shape and strength of relationships differed greatly among measures of biodiversity and among sites, the strongest relationships within each site were always those involving richness or evenness.

Sensitivities of a wildlife species, deer mice, to oxidants were evaluated. A single dose (1589 mg/kg body weight by intraperitoneal injection) of carbon tetrachloride, a typical hepatotoxicant, caused changes in GCL activity and GSH content in multiple organs of deer mice. Hepatic GCL activity and GSH content were depleted substantially (P

Contamination by hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been identified at areas of explosive manufacturing, processing, storage, and usage. Anaerobic conversion of RDX to N-nitroso metabolites (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX)) has been demonstrated in the environment and in gastrointestinal tracts of mammals in vivo. Thus, potential exists for exposure to these N-nitroso compounds. While exposed to TNX via drinking water ad libitum, deer mice (Peromyscus maniculatus) were bred in three generations to produce cohorts F1A-D, F2A-B, and F3A. TNX was administered at four exposure levels: control (0 microg L(-1)), 10 microg L(-1), 100 microg L(-1), and 1000 microg L(-1). Endpoints investigated include: offspring production, offspring survival, offspring weight gain, and offspring organ weights. TNX exposure decreased litter size and increased postpartum mortality of offspring at the highest exposure level.

Natural perchlorate is believed to be of atmospheric origin, yet no systematic study has been conducted to evaluate perchlorate deposition rate and possible seasonal or spatial variations. This study evaluated perchlorate concentrations in weekly composite wet deposition samples acquired through the National Atmospheric Deposition Program from 26 sites across the continental United States, Alaska, and Puerto Rico for a 1-3 year period. Perchlorate concentrations varied from5 ng/L to a high of 102 ng/L with a mean of 14.1 +/- 13.5 ng/L for the 1578 total samples. The annual perchlorate flux by site ranged from a low of 12.5 (TX) to 157 mg/ha-year (NE) and averaged 65 +/- 30 mg/ha-year for all sites. Perchlorate concentrations and flux in wet deposition were generally highest in May-August declining to lows in December-February. Average annual perchlorate flux was correlated (r0.5; p0.001) with Ca2+, K+, NH4+, NO3(-), Cl(-), and SO4(-2). Wet deposition rate of ClO4(-) in the conterminous United States (excluding Alaska, Hawaii, and Puerto Rico) while diffuse, represents a potential annual net mass flux of 51,000 kg, a value comparable to the estimated annual environmental releases from other known ClO4(-) sources.

New, nonparticulate decontamination materials promise to reduce both military and civilian casualties by enabling individuals to decontaminate themselves and their equipment within minutes of exposure to chemical warfare agents or other toxic materials. One of the most promising decontaminating materials has been developed using a needle-punching nonwoven process to construct a nonparticulate composite fabric of multiple layers, including an inner layer of activated carbon fabric, which is well-suited for the decontamination of both personnel and equipment. This paper describes the development of a composite nonwoven pad and compares efficacy test results for this pad with results from testing other decontamination systems. The efficacy of the dry nonwoven fabric pad was demonstrated specifically for decontamination of the chemical warfare blister agent bis(2-chloroethyl)sulfide (HD or sulfur mustard). Gas chromatography/mass spectroscopy (GC/ MS) results indicate that the composite fabric was capable of significantly reducing the vapor hazard from mustard liquid absorbed into the nonwoven dry fabric pad. The mustard adsorption efficiency of the nonwoven pad was significantly higher than that of particulate activated carbon and was similar to the currently fielded U.S. military M291 kit. The nonwoven pad has several advantages over other materials, especially its nonparticulate, yet flexible, construction. This composite fabric was also shown to be chemically compatible with potential toxic and hazardous liquids, which span a range of hydrophilic and hydrophobic chemicals, including a concentrated acid, an organic solvent, and a mild oxidant (bleach).

Species diversity and the structure of microbial communities in soils are thought to be a function of the cumulative selective pressures within the local environment. Shifts in microbial community structure, as a result of metal stress, may have lasting negative effects on soil ecosystem dynamics if critical microbial community functions are compromised. Three soils in the vicinity of a copper smelter, previously contaminated with background, low and high levels of aerially deposited metals, were amended with metal-salts to determine the potential for metal contamination to shape the structural and functional diversity of microbial communities in soils. We hypothesized that the microbial communities native to the three soils would initially be unique to each site, but would converge on a microbial community with similar structure and function, as a result of metal stress. Initially, the three different sites supported microbial communities with unique structural and functional diversity, and the nonimpacted site supported inherently higher levels of microbial activity and biomass, relative to the metal-contaminated sites. Amendment of the soils with metal-salts resulted in a decrease in microbial activity and biomass, as well as shifts in microbial community structure and function at each site. Soil microbial communities from each site were also observed to be sensitive to changes in soil pH as a result of metal-salt amendment; however, the magnitude of these pH-associated effects varied between soils. Microbial communities from each site did not converge on a structurally or functionally similar community following metal-salt amendment, indicating that other factors may be equally important in shaping microbial communities in soils. Among these factors, soil physiochemical parameters like organic matter and soil pH, which can both influence the bioavailability and toxicity of metals in soils, may be critical.

Experimental studies demonstrating that nitrogen (N) enrichment reduces plant diversity within individual plots have led to the conclusion that anthropogenic N enrichment is a threat to global biodiversity. These conclusions overlook the influence of spatial scale, however, as N enrichment may alter beta diversity (i.e., how similar plots are in their species composition), which would likely alter the degree to which N-induced changes in diversity within localities translate to changes in diversity at larger scales that are relevant to policy and management. Currently, it is unclear how N enrichment affects biodiversity at scales larger than a small plot. We synthesized data from 18 N-enrichment experiments across North America to examine the effects of N enrichment on plant species diversity at three spatial scales: small (within plots), intermediate (among plots), and large (within and among plots). We found that N enrichment reduced plant diversity within plots by an average of 25% (ranging from a reduction of 61% to an increase of 5%) and frequently enhanced beta diversity. The extent to which N enrichment altered beta diversity, however, varied substantially among sites (from a 22% increase to an 18% reduction) and was contingent on site productivity. Specifically, N enrichment enhanced beta diversity at low-productivity sites but reduced beta diversity at high-productivity sites. N-induced changes in beta diversity generally reduced the extent of species loss at larger scales to an average of 22% (ranging from a reduction of 54% to an increase of 18%). Our results demonstrate that N enrichment often reduces biodiversity at both local and regional scales, but that a focus on the effects of N enrichment on biodiversity at small spatial scales may often overestimate (and sometimes underestimate) declines in regional biodiversity by failing to recognize the effects of N on beta diversity.

We evaluated the use of the gas exchange rate as an ecologically relevant indicator of chemical stress in avian embryos/eggs. Northern bobwhite quail (Colinus virginianus) were exposed to octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) via feed containing nominal concentrations of 0, 12.5, 50.0, and 125.0 mg kg(-1). Metabolic rates (oxygen consumption) of developing quail eggs were then measured via respirometry to examine potential effects of HMX exposure. Metabolic rates were examined on 5, 9, and 21 d of incubation. Next, concentrations of HMX in embryos/eggs were determined by liquid chromatography-mass spectrometry. Mean (+/-SE) concentrations of HMX in eggs were 21.0+/-5.9, 1113+/-79.0, 3864+/-154.0, and 7426+/-301.1 ng g(-1) in control, low, medium and high dose groups, respectively. There were significant differences in oxygen consumption among the three embryo ages, however differences among the ages were not consistent among dose groups (age x dose group interaction p

To evaluate the efficacy of green tea polyphenols (GTPs) in modulating aflatoxin B(1) (AFB(1)) biomarkers, a total of 352 serum samples and 352 urine samples collected from a 3 month chemoprevention trial with 500 mg GTPs, 1000 mg GTPs and a placebo were measured for AFB(1)-albumin adducts (AFB-AA), aflatoxin M(1) (AFM(1)) and aflatoxin B(1)-mercapturic acid (AFB-NAC). Levels of AFB-AA at baseline were comparable for all three dose groups (P = 0.506). No significant differences were observed in AFB-AA levels in the placebo group over the 3 month period (P = 0.252). However, a significant reduction in AFB-AA levels was observed in the 500 mg group (P = 0.002). A marginally significant reduction in AFB-AA levels was also found in the 1000 mg group over the 3 month intervention period (P = 0.051). An analysis using a mixed-effects model indicated that the reduction in AFB-AA levels over time was dose and time dependent (dose-time interaction P = 0.049). There were no significant differences in median AFM(1) levels among the three study groups at the baseline (P = 0.832), 1 month (P = 0.188) and 3 months (P = 0.132) of the GTP intervention; however, reduction of 42 and 43% in median AFM(1) levels, as compared with the placebo, were found in 500 mg (P = 0.096) and 1000 mg (P = 0.072) groups at 3 months of the intervention. Significant elevations in median AFB-NAC levels and the ratio of AFB-NAC:AFM(1) were found in both 500 and 1000 mg groups compared with the placebo group at both 1 month (P < 0.001) and 3 months (P < 0.001) of GTPs intervention. These results demonstrate that GTPs effectively modulate AFB(1) metabolism and metabolic activation.

Health benefits of green tea polyphenols (GTPs) have been reported in many animal models, but human studies are inconclusive. This is partly due to a lack of biomarkers representing green tea consumption. In this study, GTP components and metabolites were analyzed in plasma and urine samples collected from a phase II intervention trial carried out in 124 healthy adults who received 500- or 1,000-mg GTPs or placebo for 3 months. A significant dose-dependent elevation was found for (-)-epicatechin-3-gallate (ECG) (p

Objective Atherosclerosis, rather than microcirculatory impairment caused by endothelial cell dysfunction, is the main driver of circulatory compromise in patients with diabetic limbs. The presence of atherosclerotic plaque at the trifurcation is a significant contributor to amputation of diabetic legs. The presence of bacteria and other microorganisms in atherosclerotic plaque has long been known, however, the cause of chronic inflammation and the role of bacteria/viruses in atherosclerosis have not been studied in detail. The objective of this study was to clarify the cause of the chronic inflammation within atherosclerotic plaques, and determine if any bacteria and/or viruses are involved in the inflammatory pathway. Method This study uses fluorescence microscopy and fluorescence in-situ hybridisation (FISH) to identify components of biofilm in atherosclerotic arteries. These tools are also used to identify individual bacteria, and determine the architectural spatial location within the atherosclerotic plaque where the bacteria can be found. Results The results indicate that the presence of biofilms in grossly involved arteries may be an important factor in chronic inflammatory pathways of atherosclerotic progression, in the amputated limbs of patients with diabetic foot ulcers and vascular disease. Conclusion While the presence of bacterial biofilm structures in atherosclerotic plaque does not prove that biofilm is the proximate cause of atherosclerosis, it could contribute to the persistent inflammation associated with it. Second, the synergistic relationship between the atherosclerotic infection and the diabetic foot ulcer may ultimately contribute to higher amputation rates in diabetics. Declaration of interest: RAW and RDW have equity interest in PathoGenius, a clinical laboratory using DNA to identify microbes.

Aims To examine whether co-administration of intestinal alkaline phosphatase (IAP) with antibiotics early in life may have a preventive role against metabolic syndrome (MetS) in mice. Methods A total of 50 mice were allocated to four treatment groups after weaning. Mice were treated with azithromycin (AZT) ± IAP, or with no AZT ± IAP, for three intermittent 7-day cycles. After the last treatment course, the mice were administered a regular chow diet for 5 weeks and subsequently a high-fat diet for 5 weeks. Body weight, food intake, water intake, serum lipids, glucose levels and liver lipids were compared. 16S rRNA gene pyrosequencing was used to determine the differences in microbiome composition. Results Exposure to AZT early in life rendered mice susceptible to MetS in adulthood. Co-administration of IAP with AZT completely prevented this susceptibility by decreasing total body weight, serum lipids, glucose levels and liver lipids to the levels of control mice. These effects of IAP probably occur as a result of changes in the composition of specific bacterial taxa at the genus and species levels (e.g. members of Anaeroplasma and Parabacteroides). Conclusions Co-administration of IAP with AZT early in life prevents mice from susceptibility to the later development of MetS. This effect is associated with alterations in the composition of the gut microbiota. IAP may represent a novel treatment against MetS in humans.

Background:Inthis study, the genetic substructure and morphology of the species Neusticomysmonticolus was evaluated. A nuclear marker and mitochondrial maker were used to examine phylogeographic structure and to estimategenetic distances. Two statistical measurement analyses were applied to morphological data. Results: These data recovered two morphologically distinct phylogeographic groups corresponding to populations on the eastern and western slopes of the Andes. Further, these eastern and western Andean slope populations of N. monticolus are 8.5 % divergent using sequence data from cytochrome-b (0.8 % divergent in the interphotoreceptor retinoid-binding protein gene). Conclusions:Populationscurrently assigned to N.monticolus constitutea species complex. The name N.monticolus is here restricted to western Andean slope populations. Populations on the eastern slope of the Andes are assigned to a new species, to which the authors assign the name Neusticomys vossi sp.nov.

Green tea polyphenols (GTP) effectively protect against chronic diseases in various animal models but human studies have been inconclusive. GTP components and metabolites in body fluids have been suggested as potential biomarkers, but validation of these biomarkers has rarely been done in human populations. A randomized, double-blinded, and placebo-controlled phase IIa chemoprevention study with GTP was conducted in 120 human subjects for 3 months. To validate GTP biomarker profiles, plasma samples were collected at baseline, 1-month, and 3-month and were analyzed by HPLC-Coularray electrochemical detection (ECD) for specific GTP components as well as for non-targeted metabolites. The levels of 2 GTP components, epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG), were homogenous at baseline (p > 0.45) but were significantly elevated (p

To aid in the evaluation of the potential toxicity of N-nitroso derivatives of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), we describe a pressurized liquid extraction (PLE) followed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method for determination of RDX and its N-nitroso derivatives: hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in soils. Sandy loam soil was spiked with RDX and its N-nitroso derivatives (MNX, DNX, and TNX). Acetonitrile was used as the PLE extraction solvent at 100 degrees C and 1500 psi for 15 min. Florisil was used to cleanup extracts following PLE. Instrumental analysis employed LC-ESI-MS, in which 1mM acetic acid was added to the mobile phase to facilitate formation of acetate adduct ions [M+CH(3)COO](-). The method detection limits (MDLs) for RDX, MNX, DNX, and TNX were 1.46, 1.46, 1.69, and 1.93 ng/g, respectively. High recovery (91.1-108.3%), good precision (RSD: 3.2-12.4%), and reproducibility were achieved. This method proved effective and was applied to monitor the reductive biotransformation of MNX in soils with the presence of earthworms (Eisenia fetida).

A thermogravimetric analyzer (TGA) was used for the generation of primary vapor standards of three organophosphate pesticides encompassing a wide range of vapor pressures. The technique combines a dynamic flow-through evaporation system with gravimetric analysis of weight loss from an analyte reservoir. Vapor reference standards may be produced in less than 1 h per compound, including purging the system between compounds. Vapor concentrations are gravimetrically monitored in real-time (1 Hz). Equilibration time was negligible, as the linear vaporization curves for t he compounds were produced in real-time, and all had correlation coefficients ( R 2 ) greater than 0.99. For the current study, vapors were collected by sampling bags for transport. This sensitive (parts-per-million to parts-per-billion), fast (negligible equilibration time), robust (compoun ds with vapor pressures spanning five orders of magnitude), low consumption ( L), and extremely general technique may be used for the generation of countless vapors in a number of concentrations and quantities. © 2005 Elsevier B.V. All rights reserved.

Storm surge associated with Hurricane Katrina and the breach of levees protecting New Orleans, Louisiana allowed floodwaters from Lake Pontchartrain to inundate 80% of the city. Environmental samples were collected during September 16-18, 2005 to determine immediate human and wildlife health hazards from pathogens and toxicants in the floodwaters. Baseline information on potential long-term environmental damage resulting from contaminants in water and sediments pumped into Lake Pontchartrain was also collected. Concentrations of aldrin, arsenic, lead, and seven semivolatile organic compounds in sediments/soils exceeded one or more United States Environmental Protection Agency (USEPA) thresholds for human health soil screening levels and high priority bright line screening levels. High numbers of Aeromonas spp., pathogenic Vibrio spp., and other coliform bacteria were found in floodwater samples. Alligator and snake tissues did not contain excessive toxicant concentrations. Initial findings suggest numerous environmental contaminants are present in New Orleans and support the need for further evaluation of the extent of those threats.

A solid-phase microextraction (SPME)-GC-MS method for three esters and the corresponding alcohols was tested for responses in accuracy, within-run precision (repeatability), and between-run precision (reproducibility) due to individual operators, individual analysis days, and differing analyte concentrations. At 5 ppm (v/v) [ppmv], three of the six analytes showed significant (p0.05) operator effects, while five of six analytes gave a significant effect due to the days of analysis. At 20 ppmv, five of the six analytes gave significant operator and daily effects. At 100 ppmv, all the analytes showed significant daily effects but no operator effects were observed. The repeatability was concentration dependent, with all six analytes combining for an average RSD of 12.1 +/- 6.1% at 1 ppmv, becoming most precise at 50 ppmv at 1.01 +/- 0.45%, then increasing at 100 ppmv to 4.12 +/- 1.88%. The contributors to error trended as: concentrationdaily effectsoperator.

We assessed the effects of landscape features (vegetation type and topography), season, and spatial hierarchy on the nutrient content of surface soils in the Luquillo Experimental Forest (LEF) of Puerto Rico. Considerable spatial variation characterized the soils of the LEF, and differences between replicate sites within each combination of vegetation type (tabonuco vs. palo colorado vs. dwarf vs. pasture) and topographic position (ridge vs valley) accounted for 11–60% of the total variation in soil properties. Nevertheless, mean soil properties differed significantly among vegetation types, between topographic positions, and between seasons (wet vs dry). Differences among vegetation types reflected soil properties (e.g., bulk density, soil moisture, Na, P, C, N, S) that typically are related to biological processes and inputs of water. In forests, differences between topographic positions reflected elements (e.g., Ca, Mg, K, and Al) that typically are associated with geochemical processes; however, the nutrients and elements responsible for topographic differences in dwarf forest were different from those in other forest types. In pastures, differences between topographic positions were associated with the same soil properties responsible for differences among the other vegetation types. Pastures also had reduced N levels and different soil characteristics compared to undisturbed tabonuco forest. The only soil parameter that differed significantly between seasons was soil moisture. Soils of the LEF do not support the contention that N becomes limiting with an increase in elevation, and suggest that absolute pool sizes of N and P are not responsible for the reduction in productivity with elevation.

Gross, K. L., Willig, M. R., Gough, L., Inouye, R. and Cox, S. B. 2000. Patterns of species density and productivity at different spatial scales in herbaceous plant communities. ‐ Oikos 89: 417‐427. A major challenge in evaluating patterns of species richness and productivity involves acquiring data to examine these relationships empirically across a range of ecologically significant spatial scales. In this paper, we use data from herb-dominated plant communities at six Long-Term Ecological Research (LTER) sites to examine how the relationship between plant species density and above-ground net primary productivity (ANPP) differs when the spatial scale of analysis is changed. We quantified this relationship at different spatial scales in which we varied the focus and extent of analysis: (1) among fields within communities, (2) among fields within biomes or biogeographic regions, and (3) among communities within biomes or biogeographic regions. We used species density (Dnumber of species per m 2 ) as our measure of diversity to have a comparable index across all sites and scales. Although we expected unimodal relationships at all spatial scales, we found that spatial scale influenced the form of the relationship. At the scale of fields within different grassland communities, we detected a significant relationship at only one site (Minnesota old-fields), and it was negative linear. When we expanded the extent of analyses to biogeographic regions (grasslands or North America), we found significant unimodal relationships in both cases. However, when we combined data to examine patterns among community types within different biogeographic regions (grassland, alpine tundra, arctic tundra, or North America), we did not detect significant relationships between species density and ANPP for any region. The results of our analyses demonstrate that the spatial scale of analysis ‐ how data are aggregated and patterns examined ‐ can influence the form of the relationship between species density and productivity. It also demonstrates the need for data sets from a broad spectrum of sites sampled over a range of scales for examining challenging and controversial ecological hypotheses.

HIV progression is characterized by immune activation and microbial translocation. One factor that may be contributing to HIV progression could be a dysbiotic microbiome. We therefore hypothesized that the GI mucosal microbiome is altered in HIV patients and this alteration correlates with immune activation in HIV. 121 specimens were collected from 21 HIV positive and 22 control human subjects during colonoscopy. The composition of the lower gastrointestinal tract mucosal and luminal bacterial microbiome was characterized using 16S rDNA pyrosequencing and was correlated to clinical parameters as well as immune activation and circulating bacterial products in HIV patients on ART. The composition of the HIV microbiome was significantly different than that of controls; it was less diverse in the right colon and terminal ileum, and was characterized by loss of bacterial taxa that are typically considered commensals. In HIV samples, there was a gain of some pathogenic bacterial taxa. This is the first report characterizing the terminal ileal and colonic mucosal microbiome in HIV patients with next generation sequencing. Limitations include use of HIV-infected subjects on HAART therapy., Author Summary Human immunodeficiency virus (HIV) infection related illness progresses despite the control of the virus itself by medications that stop the replication of the virus. This happens because the immune system gets activated. While the causes for such activation of the immune system are not exactly known, immune activation in HIV infection may be occurring as a result of bacteria or their products in the digestive tract. This study looks at the types of bacteria that reside in the lower intestinal tract in patients infected with human immunodeficiency virus, using state of the art sequencing technology, that can simultaneously look at thousands of bacteria. We have found that the bacteria at the end of the small bowel (an area also called the terminal ileum), at the right and left sides of the large intestine and in the stool is different in patients infected with the human immunodeficiency virus. HIV patients harbor more bacteria that have been linked to other human diseases and have been previously described as harmful. This finding is new and could open up a new frontier of study that could now pave the way to gain a deeper understanding of how the HIV causes illness.