bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of biodiversity on ecosystem, community, and population variables reported 1974–2004
Authors: Schmid Bernhard , Pfisterer Andrea B. , Balvanera Patricia
Published: February 2009

This metadata set contains 761 effects of biodiversity on ecosystem, community, or population response variables reported in 137 publications from 1974 to June 2004. All data were obtained in experimental studies. Relationships between species richness or other biodiversity measures and response variables are described by their shape, direction, significance, and if available, the simple (regression) or multiple (analysis of variance) correlation coefficient. We classified response variables into groups according to the ecosystem function or service to which they were related, the trophic level at which they were measured, and several other classification schemes. Similarly, we classified studies into groups according to ecosystem type, experimental system (bottle/pot, greenhouse, field), range and trophic level of biodiversity treatments, and further design variables. Covariates include location of study, number of plots, and number of species used in the biodiversity treatments. Analyses of these metadata have shown, for example, that biodiversity effects on community (and ecosystem) variables are often positive, and those on population variables negative, that stocks are more responsive than rates to biodiversity manipulation, and that bottom‐up biodiversity effects in multi‐trophic studies are often negative. This metadata set gives a representative overview of the results of a first generation of biodiversity experiments and allows a quantitative assessment of the influence of a number of biological and design variables on the significance and shape of the relationship between biodiversity and response variables.

The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at 〈http://esapubs.org/archive〉. (The accession number for each Data Paper is given directly beneath the title.)
Effects of biodiversity on the functioning of ecosystems: a summary of 164 experimental manipulations of species richness
Authors: Cardinale Bradley J. , Srivastava Diane S. , Duffy J. Emmett , Wright Justin P. , Downing Amy L. , Sankaran Mahesh , Jouseau Claire , Cadotte Marc W. , Carroll Ian T. , Weis Jerome J. , Hector Andy , Loreau Michel
Published: February 2009

Over the past decade, accelerating rates of species extinction have prompted an increasing number of studies to reduce the number of species experimentally in a variety of ecosystems and examine how this aspect of diversity alters the efficiency by which communities capture biologically essential resources and convert them into new tissue. Here we summarize the results of 164 experiments (reported in 84 publications) that have manipulated the richness of primary producers, herbivores, detritivores, or predators in a variety of terrestrial and aquatic ecosystems and examined how this impacts (1) the standing stock abundance or biomass of the focal trophic group, (2) the abundance or biomass of that trophic group's primary resource(s), and/or (3) the extent to which that trophic group depletes its resource(s). Our summary includes studies that have focused on the top‐down effects of diversity, whereby researchers have examined how the richness of trophic group t impacts the consumption of a shared resource, and also studies that have focused on the bottom‐up effects of diversity, whereby researchers have examined how the richness of trophic group t impacts consumption of t by the next highest trophic level. The first portion of the data set provides information about the source of data and relevant aspects of the experimental design, including the spatial and temporal scales at which the work was performed. The second portion gives the magnitude of each response variable, the standard deviation, and the level of replication at each level of species richness manipulated. The third portion of the data set summarizes the magnitude of diversity effects in two ways. First, log ratios are used to compare the response variable in the most diverse polyculture to either the mean of all monocultures or the species having the highest/lowest value in monoculture. Second, data from each level of species richness are fit to three nonlinear functions (log, power, and hyperbolic) to assess which best characterizes the shape of diversity effects. The final portion of the data set summarizes any information that helps parse diversity effects into that attributable to species richness vs. that attributable to changes in species composition across levels of richness.

The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at 〈http://esapubs.org/archive〉. (The accession number for each Data Paper is given directly beneath the title.)
Influence of liquid water and soil temperature on petroleum hydrocarbon toxicity in Antarctic soil
Authors: Schafer Alexis N. , Snape Ian , Siciliano Steven D.
Published: February 2009

Fuel spills in Antarctica typically occur in rare ice-free oases along the coast, which are areas of extreme seasonal freezing. Spills often occur at subzero temperatures, but little is known of ecosystem sensitivity to pollutants, in particular the influence that soil liquid water and low temperature have on toxicity of petroleum hydrocarbons (PHC) in Antarctic soil. To evaluate PHC toxicity, 32 locations at an aged diesel spill site in Antarctica were sampled nine times to encompass frozen, thaw, and refreeze periods. Toxicity was assessed using potential activities of substrate-induced respiration, basal respiration, nitrification, denitrification, and metabolic quotient as well as microbial community composition and bacterial biomass. The most sensitive indicator was community composition with a PHC concentration effecting 25% of the population (EC25) of 800 mg/kg, followed by nitrification (2,000 mg/kg), microbial biomass (2,400 mg/kg), and soil respiration (3,500 mg/kg). Despite changes in potential microbial activities and composition over the frozen, thaw, and refreeze period, the sensitivity of these endpoints to PHC did not change with liquid water or temperature. However, the variability associated with ecotoxicity data increased at low liquid water contents. As a consequence of this variability, highly replicated (n = 50) experiments are needed to quantify a 25% ecological impairment by PHCs in Antarctic soils at a 95% level of significance. Increases in biomass and respiration associated with changes in community composition suggest that PHC contamination in Antarctic soils may have irrevocable effects on the ecosystem.
A microtiter-plate-based cytochrome P450 3A activity assay in fish cell lines
Authors: Christen Verena , Oggier Daniela M. , Fent Karl
Published: February 2009

Enzymes belonging to the cytochrome P450 3A (CYP3A) subfamily play an important role in the metabolism of endogenous substances and xenobiotics, including pharmaceuticals. Xenobiotics can alter CYP3A expression and activity, and therefore, changes in CYP3A activity may serve as a biomarker of xenobiotic exposure. To determine changes in CYP3A enzyme activity for environmental risk assessment of xenobiotics including pharmaceuticals, high-throughput assays are needed, but these are missing for fish cells to date. Here, we report on the development of a fluorescent-based CYP3A high-throughput assay for four fish cell lines cultivated in 96-well plates based on 7-benzyloxy-4-trifluoromethylcoumarin as a CYP3A substrate. We show that human CYP3A substrate BFC is catalyzed by fish CYP3A enzymes to a fluorescent product. Its formation is dependent on cell numbers and incubation time. Furthermore, we demonstrate that with this new CYP3A assay induction and inhibition of enzyme activity by pharmaceuticals can be determined. This new cell-based assay is suitable for detection of alteration in CYP3A enzyme activity in large-scale experiments for screening of pharmaceuticals occurring in the environment.
Identification and evaluation of pyrethroid insecticide mixtures in urban sediments
Authors: Trimble Andrew J. , Weston Donald P. , Belden Jason B. , Lydy Michael J.
Published: February 2009

Organochlorine, organophosphorous, and pyrethroid insecticides frequently have been detected together as mixtures in stream sediments. To simplify mixture analyses, additive toxic responses usually are assumed but rarely are confirmed, especially for compounds with similar modes of action. The first objective of the present study was to screen a database of 24 different pesticides and 94 urban-stream sediment samples collected throughout central and northern California (USA) to identify compounds and partial mixtures that dominated sample toxicity to Hyalella azteca. Pyrethroids and chlorpyrifos were the most toxicologically relevant compounds in terms of detection frequency, contribution to overall sample toxicity, and co-occurrence in the most common mixture patterns. Organochlorine insecticides were the least toxicologically relevant compounds, with only a small percentage of samples exceeding predefined screening values. The second objective was to confirm that mixtures of type I and type II pyrethroids display additive responses. Ten-day sediment toxicity tests of binary pesticide mixtures were conducted using H. azteca as the test organism. Observed dose-response curves were compared to those predicted from concentration-addition and independent-action models. Model deviation ratios (MDRs) were calculated at the median effect level to quantify the magnitudes of deviation between observed and predicted curves. Whereas the concentration-addition model adequately predicted toxicity for all the pyrethroid mixtures (MDRs within a factor of two), dose-response values deviated from additivity enough to warrant further investigation.
Fog and Precipitation Chemistry at a Mid‐land Forest in Central Taiwan
Authors: Liang Yang‐Ling , Lin Teng‐Chiu , Hwong Jeen‐Liang , Lin Neng‐Huei , Wang Chiao‐Ping
Published: February 2009

We analyzed fog and bulk precipitation chemistry at a cloud forest in central Taiwan where mountain agriculture activities are highest. There were 320 foggy days (visibility <1000 m) recorded between April 2005 and March 2006. Fog was most frequent between April 2005 and July 2005 and in March 2006 (153/153 d) and least frequent in January 2006 (21/31 d). The total fog duration was 2415 h, representing 28% of the sampling period. Compared with bulk precipitation, fog was disproportionally enriched in NO3− and SO42– relative to K+, Ca2+, Mg2+, and NH4+, resulting in higher a content of nitric acid and sulfuric acid than weak acids or neutral salts and, therefore, higher acidity (median pH, 4.9) in fog than in bulk precipitation (median and mean pH, 5.5). The very high input of NH4+ (47 kg N ha−1 yr−1) through bulk precipitation suggests that the use of fertilizer (ammonium sulfate and animal manure) associated with mountain agriculture has a major impact on atmospheric deposition at the surrounding forest ecosystems. The input of inorganic N reached 125 kg N ha−1 yr−1 and likely exceeded the biological demand of the forest ecosystem. Sulfate is the most abundant anion in fog at Chi‐tou and in precipitation at various forests throughout Taiwan, suggesting that the emission and transport of large quantities of SO2, the precursor of SO42–, is an island‐wide environmental issue.
Surface Water Sulfate Dynamics in the Northern Florida Everglades
Authors: Wang Hongqing , Waldon Michael G. , Meselhe Ehab A. , Arceneaux Jeanne C. , Chen Chunfang , Harwell Matthew C.
Published: February 2009

Sulfate contamination has been identified as a serious environmental issue in the Everglades ecosystem. However, it has received less attention compared to P enrichment. Sulfate enters the Arthur R. Marshall Loxahatchee National Wildlife Refuge (Refuge), a remnant of the historic Everglades, in pumped stormwater discharges with a mean concentration of approximately 50 mg L−1, and marsh interior concentrations at times fall below a detection limit of 0.1 mg L−1 In this research, we developed a sulfate mass balance model to examine the response of surface water sulfate in the Refuge to changes in sulfate loading and hydrological processes. Meanwhile, sulfate removal resulting from microbial sulfate reduction in the underlying sediments of the marsh was estimated from the apparent settling coefficients incorporated in the model. The model has been calibrated and validated using long‐term monitoring data (1995–2006). Statistical analysis indicated that our model is capable of capturing the spatial and temporal variations in surface water sulfate concentrations across the Refuge. This modeling work emphasizes the fact that sulfate from canal discharge is impacting even the interior portions of the Refuge, supporting work by other researchers. In addition, model simulations suggest a condition of sulfate in excess of requirement for microbial sulfate reduction in the Refuge.
Biogeochemical Response of a Northeastern Forest Ecosystem to Biosolids Amendments
Authors: Banaitis Michael R. , Fernandez Ivan J. , Wilson Cullen , Norton Stephen A. , Dail D. Bryan
Published: February 2009

In the northeastern United States interest in the use of biosolids on forest lands is growing due to the prevalence of extensive forests and market incentives for waste disposal, yet much of the regulatory framework for biosolids land application is based on agronomic practice. This study evaluated the response of soils in a young (∼20 yr old) deciduous forest to lime‐stabilized biosolids amendments focusing on (i) the temporal and spatial evolution of the pH response, (ii) soil exchangeable cation response, (iii) the risk of trace metal accumulations, and (iv) a bioindicator of treatments (i.e., foliar chemistry). Eighteen plots were established in two study phases with lime‐stabilized biosolids loading targets of 0 (control), 4.5, 6.7, 13.4, 20.2, 26.9, and 33.6 Mg (megagram) calcium carbonate equivalents (CCE) ha−1, with the lowest target rate of addition representing the current regulated loading limit for forest biosolids applications in Maine. The pH of the O horizon increased immediately >2 pH units, and then declined with time, while B horizon pH increased gradually, taking over 1 yr to achieve ∼1.0 pH unit increase at the highest loading target. O‐horizon exchangeable Ca concentration increases dominated soil chemical change and resulted in decreases in exchangeable H and Al. Few significant increases in soil trace metal concentrations had occurred at any soil depth after 1 yr of treatment. Foliar response generally reflected changes in soil chemistry, with Ca concentration increases most significant. This research provides critical insights on forest soil response to application of lime‐stabilized biosolids and suggests opportunities for higher loading targets in forests should be examined.
White Clover Nodulation Index in Heavy Metal Contaminated Soils– A Potential Bioindicator
Authors: Manier Nicolas , Deram Annabelle , Broos Kris , Denayer Franck‐Olivier , Van Haluwyn Chantal
Published: February 2009

The morphological effects of heavy metal stress on the nodulation ability of Rhizobium spp. and growth of white clover (Trifolium repens L.) were studied in the laboratory under controlled conditions. Fourteen topsoils were collected from an area with elevated metal concentrations (Cd, Zn, and Pb). White clover was cultivated using a specialized “rhizotron” method to observe the development of root and nodule characteristics. Results show effects of increasing heavy metal concentrations on nodulation development, especially the nodulation index (i.e., the number of nodules per gram of the total fresh biomass). A significant decrease in nodulation index was observed at about 2.64 mg Cd kg−1, 300 mg Zn kg−1, and 130 mg Pb kg−1 in these soils. The sensitivity of the nodulation index in relation to other morphological characteristics is discussed further. It is proposed that the nodulation index of white clover is a suitable bioindicator of increased heavy metal concentrations in soil.
Alum Application to Improve Water Quality in a Municipal Wastewater Treatment Wetland
Authors: Malecki‐Brown Lynette M. , White John R. , Sees M.
Published: February 2009

Nutrient removal in treatment wetlands declines during winter months due to temperature. A 3‐mo (wintertime) mesocosm study was conducted to determine the effectiveness of alum in immobilizing P as well as other nutrients during this period of reduced treatment efficiency. Eighteen mesocosms, triplicate alum, and three controls or no alum were established with either Typha spp., Schoenoplectus californicus, or SAV (Najas guadalupensis‐dominated). Alum was delivered by timer at a rate of 0.81 g Al m−2 d−1 and parameters measured included: pH, soluble reactive phosphorus (SRP), total phosphorus (TP), dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN), total kjeldahl nitrogen (TKN), and soluble aluminum (Al). Alum‐treated mesocosms had significantly lower pH values (8.1) than controls (8.8), but well within the elevated pH range for aluminum toxicity. Alum significantly reduced all measured water column nutrients with the exception of ammonium N, which remained unaffected, and particulate P, which increased. This study demonstrated that seasonal low‐dosage alum application to different vegetation communities in a treatment wetland can significantly improve treatment efficiencies for SRP (87 vs. 58%) and TP (62 vs. 44%) but also increase DOC (19 vs. 0%) and TKN (12 vs. −3%) removal capacity to a lesser degree. Alum applications within close proximity of the treatment wetland effluent points should be implemented with caution due to the production of alum floc‐bound P which could potentially affect discharge permit compliance for total suspended solids or total P.
A Multi‐method Comparison of Atchafalaya Basin Surface Water Organic Matter Samples
Authors: Cook Robert L. , Birdwell Justin E. , Lattao Charisma , Lowry Mark
Published: February 2009

Surface water organic matter (OM) was isolated from two distinct sites within the Atchafalaya Basin using a combination of XAD‐8 and XAD‐4 non‐ionic macroporous resins and characterized by a suite of analytical methods, including elemental analysis, 13C cross polarization magic angle spinning nuclear magnetic resonance, attenuated total reflectance Fourier transform infrared, luminescence spectroscopy including parallel factor analysis, and ultraviolet‐visible spectroscopy. The major findings of the study are (i) despite the large differences in hydrology, optical properties, iron content, dissolved oxygen, and degree of human exploitation, the spectral and elemental signatures of the hydrophobic acids and transphilic acids fractions of the isolated OM for the different sites were remarkably similar; (ii) the luminescence characteristics of the four studied fractions provided information on the relative contributions from terrestrial and microbial input sources, as well as the degree of humification; and (iii) a detailed analysis of the total luminescence data led to a new dual excitation model based on quinone exciplexes for long wavelength emissions.
Phytoextraction of Phosphorus‐Enriched Grassland Soils
Authors: van der Salm Caroline , Chardon Wim J. , Koopmans Gerwin F. , van Middelkoop Jantine C. , Ehlert Phillip A.I.
Published: February 2009

High soil P contents in agricultural soils in the Netherlands cause excessive losses of P to surface waters. The reductions in P application rates in the present manure policy are not sufficient to reach surface water quality standards resulting from the European Water Framework Directive in 2015. Accordingly, additional measures are necessary to reduce P loading to surface water. Greenhouse experiments showed that a rapid reduction in soluble P and readily available soil P can be obtained by zero P application. However, field data confirming these findings are scarce. In 2002 a phytoextraction experiment started on four grasslands sites on sand, peat, and clay soils. The phytoextraction (mining) plots receive no P and 300 kg N ha−1 yr−1 and the grass is removed by mowing. The experiment showed that zero P application, over a period of 5 yr, led to a strong (30–90%) reduction in P concentrations in soil solution in the upper soil layer (0–0.05 m). The reduction in concentrations declined with depth. Mining also resulted in a decline in P pools in the soil solid phase. The largest decline (10–60%) was found in weakly bound P pools (water extractable P; Pw, and ammonium lactate extractable P; P‐AL), whereas reductions in more strongly bound P forms were relatively small. It may be concluded that phytoextraction appears an effective method of reducing soil P concentrations in the uppermost soil layers in a couple of years and prolonged mining may thus be effective in reducing leaching and runoff of P.
Influence of Different Organic Amendments on the Leaching and Dissipation of Terbuthylazine in a Column and a Field Study
Authors: Dolaptsoglou Christina , Karpouzas Dimitrios G. , Menkissoglu‐Spiroudi Urania , Eleftherohorinos Ilias , Voudrias Evangelos A.
Published: February 2009

Terbuthylazine (TA) is a herbicide that has been introduced for weed control in corn cultivations as a direct replacement for atrazine. Because incorporation of different organic amendments (OAs) is a common practice in this crop, this study investigated the effects of different OAs, including urban sewage sludge, poultry compost, and corn straw on the dissipation and metabolism of TA. A column study and a field dissipation study were used. In the column study, no residues of TA and desethyl‐terbuthylazine (DETA) were detected in the leachate of amended and non‐amended columns. The addition of OAs increased the persistence of TA and DETA in the upper soil layers (0–10 cm) but did not affect the mobility of TA and DETA in either experiment. Although the presence of OAs led to a significant increase in DETA production in the upper soil layers, the presence of DETA in lower depths did not significantly differ with the non‐amended soil in either experiment. A gradual accumulation of DETA was evident in the soil layers amended with corn straw, whereas a rapid formation of DETA and a gradual decline thereafter was observed in the other treatments. Overall, the addition of OAs did not appear to significantly influence the mobility of TA and DETA, which did not move below the top 30 cm, thus indicating low risk for ground water contamination. In addition, the dissipation rate of TA in the field was faster than that in the column study.
A Geo‐Referenced Modeling Environment for Ecosystem Risk Assessment: Organophosphate Pesticides in an Agriculturally Dominated Watershed
Authors: Luo Yuzhou , Zhang Minghua
Published: February 2009

A geo‐referenced modeling system was developed in this study to investigate the spatiotemporal variability of pesticide distributions and associated ecosystem risks. In the modeling system, pesticide fate and transport processes in soil‐canopy system were simulated at field scale by the pesticide root zone model (PRZM). Edge‐of‐field mass fluxes were up‐scaled with a spatially distributed flow‐routing model to predict pesticide contaminations in surface water. The developed model was applied to the field conditions of the Orestimba Creek watershed, an agriculturally‐dominated area in California's Central Valley during 1990 through 2006, with the organophosphate insecticides diazinon and chlorpyrifos as test agents. High concentrations of dissolved pesticides were predicted at the watershed outlet during the irrigation season of April through November, due to the intensive pesticide use and low stream flow. Concentration violations, according to the California aquatic life criteria, were observed for diazinon before 2001, and for chlorpyrifos during the entire simulation period. Predicted pesticide exposure levels showed potential adverse effects on certain genera of sensitive aquatic invertebrates in the ecosystem of the Orestimba Creek. Modeling assessments were conducted to identify the factors governing spatial patterns and seasonal trends on pesticide distribution and contamination potentials to the studied aquatic ecosystem. Areas with high pesticide yields to surface water were indicated for future research and additional studies focused on monitoring and mitigation efforts within the watershed. Improved irrigation techniques and management practices were also suggested to reduce the violations of pesticide concentrations during irrigation seasons.
Risks of childhood cancer among Texas watersheds, based on mothers' living locations at the time of birth
Authors: Thompson James A. , Carozza Susan E. , Bissett Wesley T. , Zhu Li
Published: February 2009

Cancer is the most common fatal disease among US children. The fetus has reduced resistance to toxic injury and is especially prone to mutagenic injury because of the high rate of cell division. A fetus can be exposed to environmental toxins through maternal consumption of contaminated water. The objective of this study was to estimate the incidence risk for childhood cancers within each watershed in Texas. The approach modeled risk for 19 cancer histotypes incorporating correlations among the cancer types and spatial correlation. Several watersheds in a very large area known as the Central Great Plains of North Texas were associated with increased risk for astrocytoma. Two watersheds near Houston, Buffalo–San Jacinto and West Galveston Bay, had increased risk for renal cancer and acute lymphoid leukemia, respectively. A watershed in South Texas, the South Laguna Madre, had increased risk for atypical leukemias. The possibility that waterborne toxins cause these childhood cancers should be investigated further.
Arsenic, As(III), and tungsten in Nevada County's private water supplies
Authors: Walker Mark , Fosbury DeEtta
Published: February 2009

In parts of the western United States groundwater used for drinking water contains high concentrations of metals, including arsenic. In a rural county in Nevada, USA, we measured concentrations of arsenic and tungsten and the proportion of arsenic occurring in trivalent form (As(III)) in tap water samples from private domestic wells in 307 households. The proportion of arsenic occurring as As(III) ranged from 0 to 100% (ave. 21%, median 1%). Tungsten concentrations ranged from 0 to 610 μg l−1 (ave. 26 μg l−1, median 2 μg l−1). Among 253 respondents who consumed water: (a) 177/253 (70%) of tap water samples contained more than 10 μg l−1 total inorganic arsenic (ave. 66 μg l−1, median 20 μg l−1); (b) As(III) occurred as a small proportion of total arsenic in most samples (ave. 22%, median 3%); and (c) tungsten occurred in concentrations ranging from below the detection limit (3 μg l−1) to a maximum of 610 μg l−1 (ave. 30 μg l−1, median 3 μg l−1). Log10 concentrations of tungsten and total arsenic in consumed water were positively correlated (log10[W]=−0.400 + 0.703(log10[AsT]), p=0.000+, adj. r2=0.53). This suggests that householders in this area were likely to be exposed to both metals simultaneously, given that 253/307 of the respondents (82%) reported consuming tap water.
Child dysentery in the Limpopo Valley: a cohort study of water, sanitation and hygiene risk factors
Authors: Gundry Stephen W. , Wright James A. , Conroy Ronán M. , Preez Martella Du , Genthe Bettina , Moyo Sibonginkosi , Mutisi Charles , Potgieter Natasha
Published: February 2009

The objective of this cohort study was to assess risk factors for child dysentery and watery diarrhoea. The study participants consisted of 254 children aged 12–24 months in rural South Africa and Zimbabwe in households where drinking water was collected from communal sources. The main outcome measure was the most severe diarrhoea episode: dysentery, watery diarrhoea or none. For dysentery, drinking water from sources other than standpipes had a relative risk ratio of 3.8 (95% CI 1.5–9.8). Poor source water quality, as indicated by Escherichia coli counts of 10 or more cfu 100 ml−1, increased risk by 2.9 (1.5–5.7). There were no other significant risk factors for dysentery and none for watery diarrhoea. In this study, endemic dysentery is associated only with faecal contamination of source water. Sources other than standpipes, including improved groundwater, are of greater risk. Remediation of water quality by treatment at source or in the household will be required to achieve access to safe drinking water in accordance with the 7th Millennium Development Goal.
Water consumption habits of a south-western Ontario community
Authors: Pintar K. D. M. , Waltner-Toews D. , Charron D. , Pollari F. , Fazil A. , McEwen S. A. , Nesbitt A. , Majowicz S.
Published: February 2009

A cross-sectional telephone survey (n=2,332) was performed to better understand the drinking water consumption patterns among residents in Waterloo Region, Ontario, Canada. We investigated the daily volume of water consumed (including tap and bottled) and factors related to that consumption. In addition, we investigated the daily volume of cold tap water consumed by those respondents who consumed no bottled water and the factors that influence this consumption. Among study respondents, 51% exclusively drank tap water, 34% exclusively drank bottled water and 14.5% drank both, with 10 to 75% of all cold water consumed in the previous day being bottled. The mean volume of water consumed in a day (including bottled and tap water) was 1.39 l. Among those who reported to exclusively consume tap water, the mean daily volume of tap water consumed was 1.45 l. The daily amount of cold water consumed in a day was lower for older respondents, more markedly for men than women. More educated respondents consumed more water during the day. Roughly 45% of households reported that they used a carbon filter to treat their water. Roughly 5% of respondents used advanced home treatment devices, including ultraviolet light, reverse osmosis, ozonation or distillation.
Chlorine inactivation of coliphage MS2 on strawberries by industrial-scale water washing units
Authors: Casteel Michael J. , Schmidt Charles E. , Sobsey Mark D.
Published: February 2009

Fruits and vegetables (produce) intended for minimal processing are often rinsed or washed in water. Chlorine and other sanitizers are used during washing to inactivate produce spoilage microbes, but such procedures may also inactivate pathogens epidemiologically linked to produce, such as hepatitis A virus (HAV). However, no information exists on the efficacy of chlorinated wash water to inactivate HAV and other viruses on produce in actual practice, because of obvious safety concerns. In contrast, coliphage MS2 (a bacterial virus) is commonly used as a surrogate for some pathogenic viruses and may be safely used in field studies. In the present investigation, strawberries seeded with MS2 were passed through industrial-scale water washing units operated with or without added sodium hypochlorite. MS2 on strawberries was inactivated by 68%, 92% and 96% at free chlorine (FC) concentrations of ≤2, 20 and 200 ppm in wash water, respectively. MS2 was detected in wash water containing ≤2 ppm FC in one trial, but was not detected in water containing 20 or 200 ppm FC. The presence and absence of MS2 in wash water containing various levels of FC highlight the importance of controlling sanitizer levels to prevent viral cross contamination of strawberries.
Faecal contamination of drinking water in a Brazilian shanty town: importance of household storage and new human faecal marker testing
Authors: Copeland Curtis C. , Beers Benjamin B. , Thompson Meghan R. , Fitzgerald Relana P. , Barrett Leah J. , Sevilleja Jesus E. , Alencar Sayonara , Lima Aldo A. M. , Guerrant Richard L.
Published: February 2009

Worldwide, contaminated drinking water poses a major health threat, particularly to child development. Diarrhoea represents a large part of the water-related disease burden and enteric infections have been linked to nutritional and growth shortfalls as well as long-term physical and cognitive impairment in children. Previous studies detailed the frequency of infection and the consequences for child health in a shanty town in north-east Brazil. To determine the frequency of contaminated water, we measured faecal contamination in primary drinking water samples from 231 randomly selected households. Risk for contamination was compared across source and storage types. Nearly a third of the study households (70/231: 30.3%) had contaminated drinking water; the source with the highest frequency of contamination was well water (23/24: 95.8%). For tap water, the type of storage had a significant effect on the susceptibility to contamination (χ2=12.090; p=0.007). The observed pattern of contamination demonstrated the relative potential contributions of both source and storage. With evidence that supports the inclusion of source and storage in water quality surveys, this study, like others, suggests that contaminated drinking water in storage vessels may be an important factor for the documented diarrhoea disease burden in the Brazilian shanty town.
Peri-urban aquatic plant culture and skin disease in Phnom Penh, Cambodia
Authors: Anh Vuong Tuan , van der Hoek Wim , Ersbøll Annette Kjær , Vicheth Chan , Cam Phung Dac , Dalsgaard Anders
Published: February 2009

A cross-sectional study with follow-up was done in five communities involved in aquaculture in peri-urban Phnom Penh, Cambodia, to assess the association between skin disease, particularly dermatitis and occupational wastewater exposure. From 200 selected households 650 household members aged≥15 years were visited and examined dermatologically three times in July 2004, January and May 2005. Overall dermatitis prevalence was 6.1%. However, all cases (116) were found in the two wastewater villages involved in aquatic plant culture. Risk factor analysis restricted to the two wastewater villages showed that involvement in wastewater-fed aquatic plant production increased the risk of dermatitis in the univariable analysis but not in the multivariable analysis. Among family members involved in wastewater-fed aquatic plant production a longer duration of daily wastewater contact did not increase the risk of dermatitis in the multivariable analysis. Wet season, older age and having a history of skin problems in the three months prior to each survey were associated significantly with dermatitis. Very few aquaculture workers applied personal protection and the factor had no significant effect on dermatitis. The present study did not show a consistent association between occupational exposure to wastewater and dermatitis, unlike similar Vietnamese studies.
Treatment of dairy wastewater by water hyacinth
Authors: Munavalli G. R. , Saler P. S.
Published: February 2009

The present study addresses potential of water hyacinth for treating small-scale dairy wastewater to satisfy effluent standards for disposal into public sewers. The batch experiments were conducted on dairy wastewater using reactor with water hyacinth and without water hyacinth. The Chemical Oxygen Demand (COD) was varied from 507 mg/L to 4,672 mg/L and the maximum Hydraulic Retention Time (HRT) adopted was 8 days. The loss of water due to evapo-transpiration and evaporation was also measured. The water hyacinth system performed better when initial COD concentration was maintained less than 1,672 mg/L for six days HRT. The performance of water hyacinth system was more effective than reference by 30% to 45% for COD removal. However, water hyacinth had no significant impact in reducing Total Dissolved Solids (TDS). The evapo-transpiration loss was almost double than the evaporation loss. The first order reaction kinetics was applicable and reaction rate parameters were estimated for various organic strengths of wastewater. The reaction rate parameters for water hyacinth system were three times higher than a system without water hyacinth and also found to vary with initial COD values. Water hyacinth can be adopted to treat dairy wastewater from small-scale dairy effectively for disposal into public sewers.
Assessment on the performance of a series of two UASB reactors compared against one of the same total volume using Anaerobic Digestion Model No 1 (ADM1)
Authors: López Iván , Passeggi Mauricio , Pedezert Alejandro , Borzacconi Liliana
Published: February 2009

The ADM1 is applied to simulate the behaviour of an Upflow Anaerobic Sludge Blanket Reactor (UASB) treating blood powder (spray dried blood meal) wastewater. Considering a completely mixed liquid phase, the model is defined by a set of differential equations which can be numerically solved. Experimental data allows validating the output of the model which is then used for performing numerous simulations. A single reactor is compared to a series of two identical reactors of half the volume each. For the same total hydraulic retention time, the series reaches an outlet concentration 74% inferior to that of the single reactor. Furthermore, for the same total conversion the volume required by the series is 43% of that of the single reactor.
Effect of temperature on anoxic sulfide oxidation and denitrification in the bulk wastewater phase of sewer networks
Authors: Mathioudakis V. L. , Aivasidis A.
Published: February 2009

Artificial dosage of nitrate in sewer networks is considered as one of the most effective methods for odor and corrosion control. However, there is limited knowledge on the effect of temperature on the transformations that takes place during anoxic conditions. Thus, two groups of batch experiments were conducted to gain insight in the involved processes in bulk phase of a septic municipal wastewater. It can be concluded that sewer denitrification, in bulk phase, can be simplified in three stages. According to the experimental results, nitrate or nitrite is utilized for autotrophic denitrification with sulfide, while heterotrophic utilization is initiated after the completion of anoxic sulfide oxidation. Moreover, temperature is proved to have a significant impact on sewer denitrification kinetic profile, as it determines the extent of temporal nitrite accumulation. The temperature coefficient of each anoxic process, including sulfide oxidation, nitrate utilization and denitrification/nitrite utilization is experimentally calculated and temperature dependent equations are developed, providing the rate of all anoxic processes in bulk phase of sewer wastewater, in any given temperature.
Applying real-time control for realization and stabilization of shortcut nitrification-denitrification in domestic water treatment
Authors: Ma Tao , Zhao Chaocheng , Peng Yongzhen , Liu Xiuhong , Zhou Li
Published: February 2009

A sequencing batch reactor (SBR) was used to treat real domestic wastewater focusing on the achievement, maintenance and the feasibility of nitrite accumulation under real-time control. Keeping temperature, MLSS and dissolved oxygen (DO) in reactor at 28±1°C, 2,400 mg/L and higher than 2.0 mg/L respectively, shortcut nitrification-denitrification was successfully achieved after about two months. But the sudden raise of ammonia loading rate (ALR) caused deterioration of nitrite accumulation and occurrence of filamentous sludge bulking. These undesirable situations could be solved by pre-anaerobic operation mode. If applying long-term real-time control strategy to supervise the nitrification course, the sludge population optimization and high nitrite accumulation rate at different DO levels could be achieved. The strategy taking pH and aeration quantity as control parameters for nitrification in SBR was put forward under invariable DO conditions in this paper. By maintaining low DO level (below 1.0 mg/L), the shortcut nitrification-denitrification could be achieved in the same reactor with simultaneous nitrification and denitrification (SND), through which the removed nitrogen accounted for 49.12% to 66.81% of total nitrogen (TN) in influent at the end of shortcut nitrification.
Optimal process pattern for simultaneous sulfur, nitrogen and carbon removal
Authors: Chen Chuan , Wang Aijie , Ren Nanqi , Deng Xuliang , Lee Duu-Jong
Published: February 2009

Denitrifying sulfide removal (DSR) process incorporates interactions between autotrophic and heterotrophic denitrifiers and reveals difficulty to achieve high removal rate of nitrogen and sulfur in practice. We compared the DSR performance of an expanded granular sludge bed (EGSB) reactor and an upflow anaerobic sludge blanket (UASB) reactor, both fed with wastewaters comprising sulfide, nitrate and acetate. The EGSB reactor can sustain at higher loading rates than UASB reactor, probably owing to the less elemental sulfur production rate for the latter in operation.
Modelling using rRNA-structured biomass models
Authors: Lavallée B. , Frigon D. , Lessard P. , Vanrolleghem P. A. , Yuan Z. , van Loosdrecht M. C. M.
Published: February 2009

Models currently used have been developed to describe the storage response in the activated sludge process. In these models the distribution of the substrate flux between growth and storage is an empirical function. rRNA-structured biomass models are proposed to describe the metabolic status of cells in view of predicting the growth response (dμ/dt) of cells in activated sludge process. The autocatalytic reaction rate of the synthesis of the PSS component (rRNA) can provide a mechanistic explanation for the growth response and the growth lag phase. The proposed models were able to describe and predict properly the growth response of the biomass in various types of reactor. Such models could be more widely applicable by using intrinsic model parameters. This would be a key improvement for as it would lead to improved models for design.
A balancing act: the consulting engineers' pragmatic view of process modelling
Authors: Copp J. B. , Johnson B. R. , Shaw A. , Burbano M. S. , Narayanan B. , Frank K. , Kinnear D. , Melcer H. , Brischke K.
Published: February 2009

Modelling: what do we know, what do we want to know and why? The practical application of models to real projects is often circular because these questions weren't asked prior to making the decision to model the plant under study. Modelling wastewater treatment plants can provide insight into the inner workings of the process that might not be attainable any other way, but is that added process knowledge always needed or necessary and what criteria does one use to determine the level of effort required? These complex modelling decisions require education, communication, and improved understanding amongst both modellers and clients. This submission explores the use of models by consultants for consulting purposes and the balancing acts (time versus knowledge and cost versus benefit) that the consulting engineer must manage when embarking on any modelling project.
Third-Degree Price Discrimination with Buyer Power
Authors: Inderst Roman , Valletti Tommaso
Published: February 2009

This paper introduces a model of third-degree price discrimination where a seller's pricing power is constrained by buyers' outside options. Price uniformity performs more efficiently than discriminatory pricing, as uniform pricing allows weaker buyers to exploit the more attractive outside option of stronger buyers. This mechanism is markedly different from the mechanisms that are at work in case uniform pricing is imposed on an unconstrained monopolist.
SEM study of compound oospore wall ornamentation of some members of Charales from Yugoslavia, Croatia and Slovenia
Authors: Mandal D.K. , Blazencic Jelena , Ray S.
Published: February 2009

The outermost layer of the oospore wall of the members of Chorales shows various ornamentation patterns, formed due to differential deposition of wall material. These ornamentations are very conservative in nature and used as taxonomic criteria in identifying species and intraspecies taxa in Chorales. In the present investigation, Scanning Electron Microscopy (SEM) was used to study the compound oospore wall ornamentations of twelve species belonging to the genera Chara, Nitella, Lamprothamnium and Lychnothamnus from Yugoslavia, Croatia and Slovenia. The taxonomic identification and systematic position of these taxa are discussed in the light of these characteristic ornamentation patterns revealed by SEM.
On two new cave pseudoscorpions: Roncus svetavodae n. sp. snd R. virovensis n. sp. (Neobisiidae, pseudoscorpiones) from southwestern Serbia
Authors: Curcic Bozidar , Dimitrijevic Rajko
Published: February 2009

Two new cave species pertaining to the pseudoscorpion family Neobisiidae Roncus svetavodae n. sp. and R. virovensis n. sp. have been described from caves in southwest Serbia. Diagnoses for each of the species are presented both taxa are endemic and relict to the area studied.
Pholeuonopsis cvijici, a new troglobitic bathysciine beetle from west Serbia - Coleoptera, Cholevidae
Authors: Curcic Srecko , Brajkovic Miloje
Published: February 2009

A new species of the troglobitic bathysciine cholevids (Pholeuonopsis cvijici n. sp) has been described from the Potpecska Pecina Cave, village Potpece, near Uzice, west Serbia. This new species is clearly distinct from its phenetically close congeners in many important respects such as: the body size, the body length to breadth ratio, the shape of the pronotum, the size of the scutellum, the shape of elytra, the form of aedeagus, the different position of setae on the apex of the paramerae, and the form of the inner sac of aedeagus. The new species belongs to an old phyletic lineage of the early Tertiary origin, and is both relict and endemic to west Serbia and the Balkan Peninsula.
Contribution to the myrmecofauna (Formicidae, Hymenoptera) of the Banat province, Serbia
Authors: Petrov Ivan
Published: February 2009

Ant species collected in the season of 1997, with some specimens of earlier years are presented. Collected species belong to the four subfamilies with the following number of species: Ponerinae (1 species), Myrmicinae (30) Dolichoderinae (6), Formicinae (30). Collected species are mostly Palearctic, European, and Southeuropean. Three Holarctic (Lasius alienus, L. flavus and L. niger) and four Mediterranean (Messor structor, Bothriomyrmex meridionalis Camponotus piceus and Cataglyphis aenescens) species were also registered. Mediterranean species are probably the remnants of the fauna of the region of Pannonian sea.
Trichoniscoides mladeni n. sp. and Androniscus roseus transsylvanicus Radu, 1960 (Isopoda, Oniscidea, Trichoniscidae) two interesting species in the fauna of Serbia, Yugoslavia
Authors: Karaman Ivo , Cemerlic D.
Published: February 2009

A detailed description of Trichoniscoides mladeni, n.sp. (Isopoda, Oniscidea, Trichoniscidae), discovered and described from Fruska Gora Mt. in Vojvodina (Serbia) is presented. This is the second finding of the members of the tyrrhenian genus Trichoniscoides Sars, 1899 far from the main range of distribution of this genus. New localities of the poorly known taxon Androniscus roseus transsylvanicus Radu, 1960 in eastern Serbia are presented, previously known only from type locality in central Romania.
Iodine and iodothyronine content in human neonate thyroid gland
Authors: Savin-Zegarac Svetlana , Cvejic Dubravka , Nedic Olgica , Radosavljevic R. , Petrovic Ivana
Published: February 2009

A few years after the iodine content of salt in Serbia was increased from 7 to 15 mg/kg NaCI, iodine, thyroxine (T4) and triiodothyronine (T3) concentrations were measured in thyroid tissue obtained at autopsy from 21 human neonates who died within 30 days after birth. The thyroidal iodine as well as T4 and T3 content per gland in?creased progressively with gestational age of human neonates (r = 0.73, 0.70 and 0.67 respectively, p < 0.001). In seven newborns (gestational age 36 to 41 weeks) the mean values for total iodine, T4 and T3 per gland were 109.1 ?g, 52.2 ?g and 4.4 ?g respectively. The results of iodine and iodothyroninc content found in neonatal thyroid gland, particularly at the end of gestation and a few days of postnatal life, indicates that the iodine supply was satisfactory.