bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlethal Sampling of Fish Caudal Fins Yields Valuable Stable Isotope Data for Threatened and Endangered Fishes
Authors: Sanderson Beth L. , Tran Chau D. , Coe Holly J. , Pelekis Vija , Steel E. Ashley , Reichert William L.
Published: October 2009

Fin clipping is gaining momentum for stable isotope analysis in fish as a nonlethal alternative to lethally collecting dorsal white muscle tissue. The main advantage of fin clipping is the elimination of lethal collection, which thus increases the potential for stable isotope research involving threatened or endangered species. To make comparisons across studies using different methods, the degree to which fin clips and dorsal muscle are correlated for both δ15N and δ13C across time and space must be quantified. We evaluated the efficacy of using caudal fin clips by comparing tissues collected across time (2003‐2005), space (21 streams), and body size (fork length, 40‐140 mm) for juvenile Chinook salmon Oncorhynchus tshawytscha and O. mykiss (rainbow trout and steelhead [anadromous rainbow trout]). We also addressed several analytical and sampling issues to assess the potential benefits and limitations of using fin clips for δ15N and δ13C determination. We found that the relationship between fin and muscle tissue was consistent across years and streams. On average, δ15N was lower in fin tissue than in muscle tissue, whereas δ13C was greater in fin tissue. Although the magnitude of the difference between fin and muscle tissue is lower than the thresholds typically used to define trophic level increases, the biological significance of these differences is context dependent. Power analyses indicated that fin and muscle tissue were equal in their ability to detect differences in δ15N and δ13C in juvenile fish and that larger sample sizes are needed to statistically quantify these differences. Finally, the use of fin clips is not a viable option for smaller fish (<50 mm) because the majority of the caudal fin is necessary for analysis. Nonetheless, fin clipping does represent a promising nonlethal sampling technique for quantifying δ15N and δ13C in juvenile salmonids.
The Interplay of Morphology, Habitat, Resource Use, and Genetic Relationships in Young Yellow Perch
Authors: Parker Aaron D. , Stepien Carol A. , Sepulveda‐Villet Osvaldo J. , Ruehl Clifton B. , Uzarski Donald G.
Published: October 2009

Morphological divergence resulting from differences in resource and habitat use is common in many fishes inhabiting postglacial ecosystems. We tested whether young yellow perchPerca flavescensdiffer in morphology, genetic composition, or diet in the nearshore (deep open‐water) versus wetland and littoral habitats (shallow zones) of Lake Michigan and Saginaw Bay, Lake Huron. Twenty‐one morphological measurements and six meristic counts were compared for 132 age‐1 yellow perch, and the genetic variation at 12 nuclear DNA microsatellite loci was assessed for a subset of age‐1 individuals across habitats and adults from nearshore zones. The results showed morphological and genetic divergence in yellow perch between Lake Michigan and Lake Huron and among those in nearshore versus wetland habitats in Lake Michigan (but not Lake Huron). Lake Huron yellow perch had deeper, longer bodies and larger dorsal fins than those from Lake Michigan. Those in nearshore habitats from both lakes had deeper, longer bodies and larger dorsal fins than did those occupying wetlands, which may reflect an adaptive response to predators and open‐water cruising. In Lake Michigan, these differences may have a genetic basis that is not apparent in Lake Huron, suggesting a role for phenotypic plasticity. Piscivorous and zooplanktivorous individuals had similar morphologies, with larger body depths than insectivores, which may be useful for fast‐starts during prey capture and provide protection from predation in open water. Comparisons of morphology, population structure, and diet thus reveal that the morphological diversity of yellow perch between habitats and lake basins reflects an interplay between phenotypic plasticity and genetic divergence.
Plasma Vitellogenin and Estradiol Concentrations in Adult Gulf Sturgeon from the Pascagoula River Drainage, Mississippi
Authors: Heise Ryan J. , Bringolf Robert B. , Patterson Rhonda , Cope W. Gregory , Ross Stephen T.
Published: October 2009

Gulf sturgeon Acipenser oxyrinchus desotoi are anadromous, the adults moving into rivers by early spring for spawning and migrating back to salt water in the fall. Because Gulf sturgeon lack readily discernable secondary sex characteristics, minimally invasive means, such as evaluation of plasma vitellogenin (an egg yolk protein precursor) and sex steroid hormones, have been used to determine gender. Our objectives were to explore the use of vitellogenin (Vtg) and estradiol (E2) to identify the gender of adult Gulf sturgeon captured in the Pascagoula River drainage and to determine whether these substances were useful in identifying which females would be spawning in a given spring. Our enzyme‐linked immunosorbent assay detected Vtg in all samples at concentrations ranging from 5.47 to 7,634.2 μg/mL. For samples collected from March through May, the plasma Vtg concentrations generally clustered into one of two groups, low (<100 μg/mL) and high (>1,000 μg/mL). During the same months, plasma E2 values followed a similar pattern of separation into low (<0.5‐ng/mL) and high (>8‐ng/mL) concentrations. Based on the clear delineation of Vtg and E2 concentrations in spring‐captured sturgeon and comparison with previous studies in which gender was definitively determined, fish with high Vtg (>1,000‐μg/mL) and high E2 (>8‐ng/mL) concentrations were putatively identified as spawning females. The plasma Vtg concentrations in 10 known males (based on the release of milt) were 13‐86 μg/mL. Our work provides the first information regarding Vtg and E2 concentrations for threatened Gulf sturgeon throughout the freshwater phase of their life cycle. It is currently unclear whether the Vtg concentrations measured in male Gulf sturgeon are within a normal range for this species in the wild or are a biomarker of endocrine disruption due to exposure to xenobiotic substances.
A License Registry Improves Sampling Efficiency for a Marine Recreational Survey
Authors: Ashford Julian R. , Jones Cynthia M. , Fegley Lynn
Published: October 2009

Marine recreational surveys that use lists of coastal households for a sampling frame have been encouraged to improve their efficiency by using angler license registries instead. However, few studies have compared surveys of license holders and coastal households or assessed the gain in efficiency. During a survey of the recreational fishery for the blue crab Callinectes sapidus in Maryland, sport crab license holder and coastal county households were sampled by telephone. Overall, 40.5% of license holder households interviewed reported activity compared with 2.7% of coastal households interviewed. The license list showed no disadvantage in statistical properties compared with coastal households. However, the response rate was low for both lists; for the license survey, 30.5% of telephone numbers called resulted in interviews compared with 29.3% for coastal households. To improve response rates, we recommend that license registries incorporate incentives and alternative information for reaching license holders, such as cell‐phone numbers and e‐mail addresses.
Development and Evaluation of a Stream Channel Classification for Estimating Fish Responses to Changing Streamflow
Authors: Peterson James T. , Jackson C. Rhett , Shea Colin P. , Li Guoyuan
Published: October 2009

Current approaches to assessing the potential effects of river regulation and water use on stream fish communities are based on physical habitat simulation and are not feasible for estimating these effects over large spatial scales. We developed a channel classification for streams in the lower Flint River basin, Georgia, based on gross channel morphology and geology and evaluated its usefulness at 23 study sites representing the four channel types in the basin. Our channel classification separated stream channel types based on dominant geology (upland residuum versus Ocala limestone) and channel form (confined versus unconfined). Fish were sampled and habitat measured at the study sites in spring, summer, and winter from 2001 to 2004, a period that included some of the lowest and highest seasonal flows ever recorded. The channel types differed with respect to diurnal variability in temperature and dissolved oxygen concentration as well as habitat characteristics (substrate, large wood). Statistical habitat modeling indicated that channel unit (e.g., pool, riffle) availability could be predicted accurately for each channel type using streamflow, with errors rates that averaged 0.7% across channel unit types. Comparisons between the accuracy of species presence and fish abundance models fit using habitat characteristics to those fit using geomorphic channel characteristics indicated similar model accuracy with slightly less bias (6% on average) for the geomorphic channel characteristics models. Our results indicate that the channel types were useful for predicting changes in habitats and stream fish presence and abundance in response to changing streamflow. Channel classification is potentially a useful and cost‐effective approach to quantifying changes in the physical environment in response to varying streamflow. Additionally, channel classification could be combined with dynamic fish population models to evaluate the effects of river regulation and water use across large spatial scales.
Temporal Stability of Genetic Variation within Natural Populations of Summer Steelhead Receiving Mitigation Hatchery Fish
Authors: Blankenship Scott M. , Small Maureen P. , Bumgarner Joseph D.
Published: October 2009

Stochastic fluctuation in allele frequencies may reflect microevolutionary processes responsible for genetic change, such as small effective population size (Ne), which is a legitimate concern for imperiled populations affected by environmental or anthropogenic factors. In salmonids, recent empirical studies have provided conflicting results regarding the consistency of within‐population genetic variation over time. In the present study, we surveyed the genetic variation at 14 microsatellite loci in two endemic populations of summer steelhead Oncorhynchus mykiss (Tucannon and Touchet) for seven consecutive years and the Lyons Ferry Hatchery stock (LFH) for 4 years. The LFH (mitigation) stock is used to enhance fishing opportunities in southeastern Washington State and not to aid in the recovery of natural populations. We observed statistically significant differences in allele frequencies between replicated collections from the same location. One of twenty‐one genic tests for the Tucannon River collections, 9 of 21 genic tests for the Touchet River collections, and all genic tests regarding LFH collections were statistically significant. Temporal variation was larger than spatial variation (0.86% and 0.44%, respectively). We also used genetic data to infer effective population sizes for natural steelhead populations and the LFH mitigation hatchery stock, with point estimates of 729.7, 599.4, and 266.7 for the Tucannon, Touchet, and LFH populations, respectively. Despite the temporal variation observed, relative genetic differentiation was stable over time, replicated collections tending to cluster together in factorial correspondence analyses of allele frequency data. However, the genetic data were consistent with the potential for gene flow between the Tucannon River and LFH populations. The potential benefits of stocking genetically differentiated hatchery fish to enhance fishing opportunities in the Tucannon River may be offset by the negative effects of hatchery introgression and the small Ne in hatchery fish.
Using Mg as a Proxy for Crystal Structure and Sr as an Indicator of Marine Growth in Vaterite and Aragonite Otoliths of Aquaculture Rainbow Trout
Authors: Veinott Geoffrey Ian , Porter T. Rex , Nasdala Lutz
Published: October 2009

Otoliths of rainbow trout Oncorhynchus mykiss reared in marine cages were analyzed by laser ablation‐inductively coupled plasma mass spectrometry to determine their Sr and Mg concentrations and by micro‐Raman spectrometry to assess mineralogy. Analyses of transects from the core of the otolith to the growing edge (incorporating otolith material produced during freshwater hatchery and marine cage growth) revealed that these transects were composed of aragonite, vaterite, or both. The concentration of Sr varied significantly between mineral polymorphs and environments (hatchery or marine). In vaterite transects, Sr concentrations increased an average of 130 μg/g between freshwater hatchery growth and marine growth. This increase represents a near doubling of the Sr concentration in vaterite and made Sr a suitable indicator of a change in the environment as reflected in vaterite transects. In aragonite transects, Sr concentrations increased an average of 1,330 μg/g between hatchery and marine growth, which simplified the identification of the timing of marine transfer. The concentrations of Mg also varied significantly between mineral polymorphs, the difference in the average concentration between aragonite and vaterite being 1,179 μg/g. This allowed for the use of Mg as a proxy for mineralogy. While there was an increase in Mg concentration between hatchery and marine growth in some vaterite otoliths, the change was small compared with the change as a result of mineralogy. The average aragonite‐vaterite partition coefficients were 5.238 and 8.096 for Sr and 0.057 and 0.128 for Mg for hatchery and marine growth, respectively.
Local Habitat, Watershed, and Biotic Factors Influencing the Spread of Hybridization between Native Westslope Cutthroat Trout and Introduced Rainbow Trout
Authors: Muhlfeld Clint C. , McMahon Thomas E. , Boyer Matthew C. , Gresswell Robert E.
Published: October 2009

The invasion of nonnative fishes in freshwater systems is often facilitated by the interaction of biotic and abiotic factors operating at multiple spatial and temporal scales. We evaluated the association of local habitat features (width, gradient, and elevation), watershed characteristics (mean and maximum summer water temperatures, the number of road crossings, and road density), and biotic factors (the distance to the source of hybridization and trout density) with the spread of hybridization between native westslope cutthroat troutOncorhynchus clarkii lewisiand introduced rainbow troutO. mykissin the upper Flathead River system in Montana and British Columbia. The presence of hybridization and the proportion of rainbow trout admixture were estimated using seven diagnostic microsatellite loci. We defined logistic and linear regression models including various combinations of spatial and environmental factors and used an information‐theoretic approach to evaluate the relative plausibility of these models. Models combining measures of water temperature, disturbance, and source connectivity were the best‐approximating ones for the presence of hybridization. Hybridization was positively associated with mean summer water temperature and the number of upstream road crossings and negatively associated with the distance to the main source of hybridization. The best‐approximating models associated with the level of introgression among hybridized sites included measures of temperature, source connectivity, and the density of trout. The proportion of rainbow trout admixture was negatively related to the distance to the source and positively related to mean summer water temperature and density. Our results suggest that hybridization is more likely to occur and spread in streams with warm water temperatures, increased land use disturbance, and proximity to the main source of hybridization. However, habitat features alone may not limit the spread of hybridization; populations with high proportions of admixture and high densities may have to be reduced or eliminated.
The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Authors: Shoup Daniel E. , Wahl David H.
Published: October 2009

Turbidity in aquatic systems can change rapidly, affecting the visual ability of predators. Increased turbidity is known to reduce the reactive distance and foraging success of some planktivores and insectivores, leading to decreased growth rates. However, little is known about the effects of turbidity on prey selection by piscivores. We examined the interactions between largemouth bass Micropterus salmoides and their prey in 1.8‐m‐diameter tanks (58 cm deep) at four turbidity levels (0, 5, 10, and 40 nephelometric turbidity units [NTU]). Prey selectivity was significantly affected by turbidity. At lower turbidity levels (0 and 5 NTU), largemouth bass consumed mostly gizzard shad Dorosoma cepedianum and bluegills Lepomis macrochirus and had negative selectivity for northern crayfish Orconectes virilis. At 10 NTU, all three prey types had similar selectivity, presumably because the largemouth bass had more difficulty in capturing rapidly moving fish prey as their reactive distances decreased. At 40 NTU, the overall foraging rate was much lower and bluegills were selected significantly more often than the other prey types. Low light levels at the bottom of the tanks combined with reductions in visual clarity from clay sediments probably made it difficult for largemouth bass to feed effectively on virile crayfish at higher turbidities. Our results suggest that trophic interactions may be altered as turbidity levels change.
Examining the Correlates of Aggression Among Male and Female Vietnam Veterans
Authors: Taft Casey T. , Monson Candice M. , Hebenstreit Claire L. , King Daniel W. , King Lynda A.
Published: October 2009

This study examined the correlates of general aggression among a nationally representative sample of male and female Vietnam veterans (N = 1,632). Findings indicated that the rates of aggression for men and women were 41% and 32%, respectively, and men appeared to perpetrate relatively more acts of severe aggression. Correlates of aggression for men included lower socioeconomic status and age, minority status, unemployment, degree of exposure to the malevolent war-zone environment and perceived threat in the war zone, posttraumatic stress disorder, antisocial personality disorder, major depressive episode, alcohol abuse/dependence, and drug abuse/dependence. For women, only lower age and unemployment were associated with aggression. Findings highlight the importance of developing models for aggression among those experiencing military deployments.
Internal recycle to improve denitrification in a step feed anoxic/aerobic activated sludge system
Authors: Boyle C. A. , McKenzie C. J. , Morgan S.
Published: October 2009

During periods of low load (weekends and holidays) the Mangere wastewater treatment plant effluent has breached the summer consent conditions for total nitrogen. The purpose of this research was to determine if an internal recycle would improve nitrogen removal in the anoxic/aerobic activated sludge reactors sufficient to meet the summer resource consent standard. The recycle returned nitrate rich mixed liquor from the downstream aerobic zone back to the initial anoxic zone, thus potentially improving denitrification. A full scale trial showed that installation of the internal recycle on each RC would have satisfied the resource consent for total nitrogen in most cases over the three summer resource consent periods since the upgrade. However, further modifications of the internal recycle would be required to ensure that consent conditions were satisfied at all times and to improve the consistency of the results.
Wastewater treatment models in teaching and training: the mismatch between education and requirements for jobs
Authors: Hug Thomas , Benedetti Lorenzo , Hall Eric R. , Johnson Bruce R. , Morgenroth Eberhard , Nopens Ingmar , Rieger Leiv , Shaw Andrew , Vanrolleghem Peter A.
Published: October 2009

As mathematical modeling of wastewater treatment plants has become more common in research and consultancy, a mismatch between education and requirements for model-related jobs has developed. There seems to be a shortage of skilled people, both in terms of quantity and in quality. In order to address this problem, this paper provides a framework to outline different types of model-related jobs, assess the required skills for these jobs and characterize different types of education that modelers obtain “in school” as well as “on the job”. It is important to consider that education of modelers does not mainly happen in university courses and that the variety of model related jobs goes far beyond use for process design by consulting companies. To resolve the mismatch, the current connection between requirements for different jobs and the various types of education has to be assessed for different geographical regions and professional environments. This allows the evaluation and improvement of important educational paths, considering quality assurance and future developments. Moreover, conclusions from a workshop involving practitioners and academics from North America and Europe are presented. The participants stressed the importance of non-technical skills and recommended strengthening the role of realistic modeling experience in university training. However, this paper suggests that all providers of modeling education and support, not only universities, but also software suppliers, professional associations and companies performing modeling tasks are called to assess and strengthen their role in training and support of professional modelers.
Metabolic models to investigate energy limited anaerobic ecosystems
Authors: Rodríguez J. , Premier G. C. , Guwy A. J. , Dinsdale R. , Kleerebezem R.
Published: October 2009

Anaerobic wastewater treatment is shifting from a philosophy of solely pollutants removal to a philosophy of combined resource recovery and waste treatment. Simultaneous wastewater treatment with energy recovery in the form of energy rich products, brings renewed interest to non-methanogenic anaerobic bioprocesses such as the anaerobic production of hydrogen, ethanol, solvents, VFAs, bioplastics and even electricty from microbial fuel cells. The exisiting kinetic-based modelling approaches, widely used in aerobic and methanogenic wastewater treatment processes, do not seem adequate in investigating such energy limited microbial ecosystems. The great diversity of similar microbial species, which share many of the fermentative reaction pathways, makes quantify microbial groups very difficult and causes identifiability problems. A modelling approach based on the consideration of metabolic reaction networks instead of on separated microbial groups is suggested as an alternative to describe anaerobic microbial ecosystems and in particular for the prediction of product formation as a function of environmental conditions imposed. The limited number of existing relevant fermentative pathways in conjunction with the fact that anaerobic reactions proceed very close to thermodynamic equilibrium reduces the complexity of such approach and the degrees of freedom in terms of product formation fluxes. In addition, energy limitation in these anaerobic microbial ecosystems makes plausible that selective forces associated with energy further define the system activity by favouring those conversions/microorganisms which provide the most energy for growth under the conditions imposed.
Using Geographical Information Systems (GIS) as an instrument of water resource management: a case study from a GIS-based Water Safety Plan in Germany
Authors: Wienand I. , Nolting U. , Kistemann T.
Published: October 2009

Following international developments and the new WHO Drinking Water Guidelines (WHO 2004) a process-orientated concept for risk, monitoring and incident management has been developed and implemented in this study. The concept will be reviewed with special consideration for resource protection (first barrier of the multi-barrier system) and in turn, for the Water Safety Plan (WSP) which adequately considers—beyond the current framework of legal requirements—possible new hygienic-microbiologically relevant risks (especially emerging pathogens) for the drinking water supply. The development of a WSP within the framework of risk, monitoring and incident management includes the application of Geographical Information Systems (GIS). In the present study, GIS was used for visualization and spatial analysis in decisive steps in the WSP. The detailed process of GIS-supported implementation included the identification of local participants and their tasks and interactions as an essential part of risk management. A detailed ecological investigation of drinking water conditions in the catchment area was conducted in addition to hazard identification, risk assessment and the monitoring of control measures. The main task of our study was to find out in which steps of the WSP the implementation of GIS could be integrated as a useful, and perhaps even an essential tool.
Model-based comparison of two ways to enhance WWTP capacity under stormwater conditions
Authors: Ahnert M. , Tränckner J. , Günther N. , Hoeft S. , Krebs P.
Published: October 2009

Two different approaches to increase the fraction of combined water treated in the wastewater treatment plant (WWTP) which would otherwise contribute to combined sewer overflows (CSO) are presented and compared based on modelling results with regard to their efficiencies during various rain events. The first option is to generally increase the WWTP inflow according to its actual capacity rather than pre-setting a maximum that applies to worst case loading. In the second option the WWTP inflow is also increased, however, the extra inflow of combined water is bypassing the activated sludge tank and directly discharged to the secondary clarifier. Both approaches have their advantages. For the simulated time series with various rain events, the reduction of total COD load from CSOs and WWTP effluent discharged to the receiving water was up to 20% for both approaches. The total ammonia load reduction was between 6% for the bypass and 11% for inflow increase. A combination of both approaches minimises the adverse effects and the overall emission to the receiving water.
Detection and quantification of Microcystis spp. and microcystin-LR in Western Lake Erie during the summer of 2007
Authors: Wang Hui , Gruden Cyndee L. , Bridgeman Thomas B. , Chaffin Justin D.
Published: October 2009

Microcystis spp. blooms have occurred annually in western Lake Erie since about 1995. Microcystis produce a group of toxins known as microcystins which can be harmful to livestock and to humans. In this study, surface water samples were collected from six sites during six sampling events from July to October in 2007. In situ environmental data (e.g. pH, temperature) and laboratory analyses (e.g. nutrients) were carried out to characterize the six sites. The Microcystis spp. density ranged from 102 to 107 cells/ml. Microcystin-LR concentration of 20 of all 36 samples were below the detection limit (0.15–5 ppb), while the microcystin-LR concentration in the 16 remaining samples ranged from 0.5 to 3 × 103 μg per gram dry weight. The aim of this research was to investigate the relationships between sampling location, environmental parameters, Microcystis spp. concentration, and microcystin-LR concentration. The results suggest that temperature, nutrient concentration, turbidity, and wind speed and direction (P<0.05) are factors which affected Microcystis spp. density. Sampling site 8M, located 13 m from the Maumee River, provided an advantage for Microcystis spp. growth, presumably due to intermediate water depth (5.5 m) combined with impact from the river. No relationship was found between Microcystis spp. density and microcystin-LR concentration. Temperature, nutrient concentration and DO (P<0.05) were associated with the production of microcystin-LR.
A methodological approach for direct quantification of the activated sludge floc size distribution by using different techniques
Authors: Govoreanu R. , Saveyn H. , Van der Meeren P. , Nopens I. , Vanrolleghem P. A.
Published: October 2009

The activated sludge floc size distribution (FSD) is investigated by using different measurement techniques in order to gain insight in FSD assessment as well as to detect the strengths and limitations of each technique. A second objective was to determine the experimental conditions that allow a representative and accurate measurement of activated sludge floc size distributions. Laser diffraction, Time Of Transition (TOT) and Dynamic Image Analysis (DIA) devices were connected in series. The sample dilution liquid, the dilution factor and hydraulic flow conditions avoiding flocculation proved to be important. All methods had certain advantages and limitations. The MastersizerS has a broader dynamic size range and provides accurate results at high concentrations. However, it suffers from an imprecise evaluation of small size flocs and is susceptible to particle shape effects. TOT suffers less from size overestimation for non-spherical particles. However, care should be taken with the settings of the transparency check. Being primarily a counting technique, DIA suffers from a limited size detection range but is an excellent technique for process visualization. All evaluated techniques turned out to be reliable methods to quantify the floc size distribution. Selection of a certain method depends on the purpose of the measurement.
Enhanced ammonium removal from liquid anaerobic digestion residuals in an advanced sequencing batch reactor system
Authors: Mayer M. , Smeets W. , Braun R. , Fuchs W.
Published: October 2009

When treating effluents from anaerobic processing of organic wastes, the challenge lies in the large quantity of recalcitrant COD and in the high nitrogen content. The data presented in this study illustrate an advanced SBR concept that is able to significantly reduce the organic load. It was found that undigested mashed bio-waste bypassing the anaerobic digestion is highly suitable as an external carbon source to compensate deficiencies of readily biodegradable BOD required for denitrification. In order to utilize the carbon source as efficiently as possible, the SBR was operated in a mode by which nitrification/denitrification is achieved by a shortcut process using nitrite. This procedure reduced the requirement of an external carbon source to only 5% (v/v). Moreover, through an optimized SBR sequence for an influent concentration of 14,000 mg COD/l and 3,800 mg TN/l, nearly complete removal of nitrogen (>95%) was achieved. The average removal rates for COD and BOD were 83% and 86%, respectively. The applied hydraulic retention time (HRT) of the SBR was 6.8 days. The elevated temperature of 30–41°C in the reactor as a result of the high biological activity was advantageous in terms of enhanced reaction kinetics and also provided better process stability.
Chemically enhanced primary treatment (CEPT) for removal of carbon and nutrients from municipal wastewater treatment plants: a case study of Shanghai
Authors: Wang Hongtao , Li Fengting , Keller Arturo A. , Xu Ran
Published: October 2009

With Chemically Enhanced Primary Treatment (CEPT) as the short-term process, the capacity of Bailonggang Wastewater Treatment Plant accounts for almost 25% of the total capacity of wastewater treatment in Shanghai, China. However, shortly after this plant was placed in operation in 2004, it was found that the effluent of CEPT couldn't meet the new national discharge criteria. Although the removal of phosphate is almost 80%, chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) in the effluent is frequently found to exceed the standards. The primary goal of this research is to investigate the possibility of optimizing the CEPT to make it meet the discharge criteria before it is upgraded to a secondary treatment. An oxidant is adopted to remove NH3-N, and a high performance polyaluminum chloride (HP-PACl) is synthesized to enhance the removal of COD. It is found that HP-PACl improves the removal of COD, and the oxidant enhances NH3-N removal effectively. However, to meet the requirement of a newly implemented stricter discharge standard, it is necessary to upgrade this CEPT to a secondary treatment. The results of this study provide scientific evidence for the upgrade of the Bailonggang Wastewater Treatment Plant.
Removal of organic matter and nitrogen in an horizontal subsurface flow (HSSF) constructed wetland under transient loads
Authors: Albuquerque A. , Arendacz M. , Gajewska M. , Obarska-Pempkowiak H. , Randerson P. , Kowalik P.
Published: October 2009

A monitoring campaign in a horizontal subsurface flow constructed wetland under the influence of transient loads of flow-rate, organic matter, nitrogen and suspended solids showed an irregular removal of COD and TSS and lower both removal efficiencies and mass removal rates than the ones observed in other studies for similar operating conditions. This circumstance is associated to the presence of large amount of particulate organic matter from non-point sources. The mass removal rate of ammonia increased 39% as both the water and soil temperatures increased from weeks 1–8 to weeks 9–14. A good correlation between mass load and mass removal rate was observed for all measured parameters, which attests a satisfactory response of the bed under to transient loads.
Implications of reactor type and conditions on first-order hydrolysis rate assessment of maize silage
Authors: Pabón Pereira C. P. , Zeeman G. , Zhao J. , Ekmekci B. , van Lier J. B.
Published: October 2009

The biodegradability and first-order hydrolysis coefficient of maize silage have been assessed from batch experiments using different types of inoculum and substrate to inocula (S/I) ratios, and from CSTRs working at different hydraulic retention times (HRTs). In the batch experiments, the assessed maximum biodegradability of the maize silage was 68 (±2.7)% and 73(±2.9)% while the first order hydrolysis was 0.26 (±0.01) and 0.27(±0.02) d−1, using granular and a mixture of granular and suspended inoculum, respectively. In the CSTR experiment biodegradability ranged from 41–65% depending on the HRT applied whereas the calculated first order hydrolysis coefficient was 0.32 d−1. It is concluded that batch experiments can be used to assess first order hydrolysis constants and biodegradability provided that a well balanced inoculum is guaranteed. Further, it is shown that CSTR reactors digesting maize silage and operating at HRTs as low as 20 days can attain 88% of maximum biodegradability as long as pH fluctuations are minimized. 2 mmol NaHCO3 per gram maize silage was calculated to suffice for the purpose.
Removing textile mill effluent recalcitrant COD and toxicity using the H2O2/UV system
Authors: Mounteer A. H. , Leite T. A. , Lopes A. C. , Medeiros R. C.
Published: October 2009

The potential of the H2O2/UV process for improving quality of an industrial textile effluent before biological treatment was evaluated in the laboratory using a multivariate experimental design to determine the effects of pH, H2O2 dose and reaction time on colour, COD and toxicity removal efficiencies. Increasing reaction time (from 10 to 120 min) and H2O2 dose (from 0 to 5 mmol L−1) significantly improved removal efficiencies, while increasing pH (from 4 to 10) had a negative effect on colour and toxicity removals. Laboratory H2O2/UV treatment of the mill effluent under optimum conditions (pH 7, 5 mmol L−1 H2O2, 120 min) resulted in decreases in colour (70%), COD (21%) and toxicity (67%), without lowering BOD. H2O2 was consumed within the first 30–60 min, while the effluent average oxidation state stabilized after 60 min. Decreasing reaction time to 60 min resulted in similar colour (63%) and COD (20%) removals but lower toxicity removal (44%). Spectrophotometric monitoring of the optimized reaction indicated partial destruction of residual aromatic azo dyes. H2O2 and residual peroxide and average oxidation state of the effluent Effluent biodegradability (BOD/COD) increased by 28% after the H2O2/UV treatment. Improvements observed in effluent quality are expected to enhance combined AOP-biological treatment efficiency of the mill effluent.
Fenton treatment efficacy for the purification of different kinds of wastewater
Authors: Trapido M. , Kulik N. , Goi A. , Veressinina Y. , Munter R.
Published: October 2009

The Fenton chemistry comprises both the classical Fenton reagent and its modification, so-called Fenton-like techniques, which have received great attention as a promising technology for wastewater treatment. In the present study real wastewater from different sources (leachate from oil shale semicoke landfill, pharmaceutical effluents from medical ointment production, municipal landfill leachate and wastewater originated from food-processing) were treated by means of Fenton/Fenton-like systems. The effectiveness of wastewater treatment was assessed by COD removal. Additionally, biodegradability improvement (BOD7/COD) and acute toxicity reduction of investigated wastewater samples were observed. The application of the Fenton chemistry to wastewater samples with different origin resulted generally in 70% or higher COD removal. Thus, the Fenton could be effectively applied both as a single treatment method and pre-treatment step to improve subsequent biodegradability of wastewater effluents.
Dry and wet weather microbial characterization of the Chicago area waterway system
Authors: Rijal G. , Petropoulou C. , Tolson J. K. , DeFlaun M. , Gerba C. , Gore R. , Glymph T. , Granato T. , O'Connor C. , Kollias L. , Lanyon R.
Published: October 2009

The Chicago Area Waterway System (CAWS) is a man-made channel, which serves the Chicago area for the drainage of urban storm water and the conveyance of secondary treated effluent from the Metropolitan Water Reclamation District of Greater Chicago's (District) North Side, Stickney and Calumet water reclamation plants (WRPs). A microbial characterization of the CAWS upstream and downstream of the WRPs and from the WRP outfall was initiated by collecting dry and wet weather samples and analyzing for indicators and pathogens. During dry weather, indicator bacteria (fecal coliform [FC], E. coli [EC], enterococci [EN]) were the most abundant microbial species detected in the CAWS compared to pathogens (Salmonella spp [SA], enteric viruses [EV], adenovirus [AV], norovirus [NV] and Giardia and Cryptosporidium). Pseudomonas aeruginosa [PA] levels in the outfall samples were either lower or equivalent to the CAWS. The wet weather samples had a higher frequency of detection of indicator bacteria and pathogens compared to dry weather samples. Overall, the concentrations of pathogens in the CAWS, representing the weather conditions experienced in a recreational year, were relatively low. The study concluded that the presence of pathogens in the CAWS downstream of the WRPs were due to secondary loading of the waterway under wet weather conditions from combined sewer overflows (CSOs) and other discharges.
Influence and modelling of urban runoff on the peak flows in rivers
Authors: Vaes G. , Feyaerts T. , Swartenbroekx P.
Published: October 2009

Surface waters and urban drainage systems are usually studied separately. However there are important interactions between both systems. Urban drainage systems can have an important impact on the surface waters, mainly at combined sewer overflows. On the other hand during periods of high water levels in a river, the runoff from the urban drainage system can be significantly influenced by backwater, which increases the probability of flooding in is not obvious, because the modelling tools for both systems are often hard to combine properly. To properly assess the probability of flooding for this kind of integrated water systems, different submodels are needed for both subsystems. In practice often one single model is used to describe the runoff to rivers despite the presence of urban catchments. The main objective of this study is to show the limits of this simplified approach. Furthermore, it is necessary to use continuous long term simulations, because of the differences in runoff behaviour. Detailed hydrodynamic models do not really fit for this purpose because of long simulation times and high demands in memory and disk space. Therefore simplified conceptual models are more useful.
Young's Modulus and Degree of Conversion of Different Combination of Light-Cure Dental Resins
Authors: Emami N , Söderholm KJ
Published: October 2009

Objectives:

To evaluate Young's modulus and degree of conversion of several combinations of bisGMA, UEDMA, TEGDMA light-cure dental resin.

Methods:

Young's modulus and DC% were studied for 21 different resin combinations of bisGMA, TEGDMA and UEDMA. Small universal testing machine and photo-calorimetry were used for the tests. The results were evaluated using ANOVA and Duncan's multiple range tests and regular t-test.

Results:

Young's modulus varied between 2.37±0.2 GPa (100% TEGDMA) and 4.15±0.2 GPa (100% bisGMA). By adding TEGDMA to bisGMA or UEDMA, the Young's modulus decreased significantly (p<0.05). Degree of conversion was significantly (p<0.05) higher when the wt% of TEGDMA was high in the mixtures than for highly concentrated bis-GMA (resin mixtures with TEGDMA in comparison to mixture with bisGMA had higher degree of conversion). DC% was significantly higher (p<0.05) for binary mixtures of UEDMA and TEGDMA, and significantly lower for 100 wt% bis-GMA (p<0.05). The DC% values were between 53.1%±0.9% (100% bisGMA) and 85.6%±1% (80% UEDMA-20% TEGDMA). The concentration of bisGMA, in the monomer mixture, affected DC% and Young's modulus oppositely.

Conclusions:

The differences in the values for DC% were mostly justified by the differences in the molecular structures of the different monomers. It was also revealed that higher DC% does not always result in a higher Young's modulus, because molecular and network structural parameters play major roles in the final physical properties of the mixtures.
Probability-Based Scoring Function as a Software Tool Used in the Genome-Based Identification of Proteins from Spirulina platensis
Authors: Wimada Thammasorn , Korakot Eadjongdee , Apiradee Hongsthong , Kriengkrai Porkaew , Supapon Cheevadhanarak
Published: October 2009

One of the major goals of proteomic research is the identification of proteins, a goal that often requires various software tools and databases. These tools have to be able to handle large amounts of data, such as those generated by PMF (Peptide Mass Fingerprinting), a high throughput technique. A newly sequenced organism, Spirulina platensis, was recently used to generate an in silico database, and thus an in-house tool designed for compatibility with this database and its inputs (PMF) was constructed in the present study. With a probability based scoring function, this tool effectively ranked ambiguous protein identification results by using five criteria: score, number of matched peptides, % coverage, pI and molecular weight. As a result, the protein identification step of Spirulina proteomic studies can be achieved precisely. Moreover, a very useful function of this tool is its capability for batch processing, in which the system can handle proteinidentification searches of a hundred of proteins automatically, from a single user’s input. Therefore, the tool not only gives accurate protein identification results but also saves the user time in processing a large amount of data.
Classroom Support for Inclusion in England and Ireland: An Evaluation of Contrasting Models
Authors: Rose Richard , O'Neill Áine
Published: October 2009

When reporting on those conditions which they perceive as necessary for the inclusion of students with special educational needs, teachers often refer to the importance of additional adult support in the classroom. The deployment of teaching assistants in England and special needs assistants in Ireland has been regarded as an important factor in supporting national policies for inclusion in both countries. This article reports on research which through survey and interview methods investigated the working practices of these colleagues and discusses the different approaches to their deployment in schools. It is suggested that whilst there are clear distinctions between the operations of the teaching assistant in England and the special needs assistant in Ireland, both play a distinct and essential role in the development of inclusive schooling. The article considers how two distinctive models of classroom support have emerged and the different ways in which they impact upon inclusion. Consideration is given to the changes which are taking place in the development of classroom teams and the ways in which this may impact upon current and future inclusion agendas.
Transatlantic Conversations about Inclusive Education: France and Nova Scotia
Authors: Schneider Cornelia , Harkins Mary Jane
Published: October 2009

Inclusive education has become an international educational priority with the ratification of the UN Convention on the Rights of Persons with Disabilities. This article compares and analyses in depth two different educational systems on two continents with regard to their development of inclusive education and their current issues with this policy. France and Nova Scotia, a Canadian province, have two different traditions of schooling and of the education of children with disabilities. The article will compare the educational systems, educational policies, definitions of inclusive education, and the shifting teachers' roles and responsibilities. Two case studies will be used to contextualize the layers of meaning underlying inclusive education.
Cervical vertebral fracture in a Thoroughbred filly with minimal neurological dysfunction
Authors: Muno J. , Samii V. , Gallatin L. , Robertson J. , Chase J.
Published: October 2009

Vertebral fractures in horses are relatively common and often occur due to trauma. Clinical signs may range from neck pain and mild neurological dysfunction to tetraplegia and death. Severity of signs and prognosis depends on extent of damage to the spinal cord. In this Case Report, serial radiographs, which track the bony changes associated with fracture healing, were performed over one year. Although surgical techniques have been described to repair fractures to the vertebrae, patients with minimal neurological deficit may have a favourable outcome with conservative medical management, as in this case.
Gastrointestinal nonrotation in a neonatal foal
Authors: Dahlberg J. A. , Adam E. N. , Palmer J. E. , Parente E. J.
Published: October 2009

A 24‐hour‐old Welsh‐Thoroughbred foal presented for routine surgical repair of an abdominal and body wall hernia. The colt became acutely colicky and emergency celiotomy was performed revealing abnormal anatomical configuration of the gastrointestinal tract (GIT). Incomplete gastrointestinal rotation is a rare congenital anomaly only described in man. This report describes the clinical and diagnostic findings, surgical and medical treatment, and outcome of a neonatal foal with nonrotation of the GIT.
Scapula stress fractures in Thoroughbred racehorses: Eight cases (1997–2006)
Authors: Vallance S. A. , Lumsden J. M. , O'Sullivan C. B.
Published: October 2009

No case series exists in the literature describing scapula stress fractures. The purpose of this study was to review the clinical findings, diagnostic images and outcome of 8 horses diagnosed with scapula stress fractures.

Scapula stress fractures were seen in Thoroughbred racehorses displaying acute moderate forelimb lameness. Nuclear scintigraphy identified the mid‐distal scapula spine and/or scapula supraspinous fossa as predilection sites. Conservative management resulted in a good prognosis for return to racing, but stress fracture recurrence may be seen.