bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper-induced modifications of the trophic relations in riverine algal-bacterial biofilms
Authors: Barranguet Christiane , van den Ende Frank P. , Rutgers Michiel , Breure Anton M. , Greijdanus Marianne , Sinke Jan J. , Admiraal Wim 
Published: March 2010

AbstractThe effects of copper (Cu) on photosynthetic riverine biofilms were studied in artificial stream channels. Direct effects on the composition and functioning of the biofilms were investigated using plant pigments, community-level physiological profiles (CLPP), and pulse-amplitude-modulated (PAM) fluorescence. Copper caused a significant reduction of microalgal biomass and induced a shift in the population from diatoms to cyanobacteria. However, a decrease in biomass indicated that the replacement of species was not totally effective to counteract the toxic effects of Cu. A direct effect of Cu could also be shown in the bacterial community, and, furthermore, changes in the CLPP could be related to the Cu treatment. Copper-exposed biofilms lost the capacity to use between 11 and 15% of the substrates, but many of the remaining capacities became more robust, indicating an increased Cu tolerance due to the exposure. The change in the biofilm microbial composition points to the indirect effects of Cu on biofilms due to the close interdependence between biofilm autotrophic and heterotrophic compartments. Grazing by snails, which appeared to be an important factor structuring biofilms without any Cu addition, had a very minor effect on Cu-exposed biofilms. Although grazing changed the bacterial composition, its effects were not detected either on the algal community or on the biofilm community tolerance to Cu.
Mechanism of acute silver toxicity in Daphnia magna
Authors: Bianchini Adalto , Wood Chris M. 
Published: March 2010

Abstract
Daphnids (Daphnia magna) were exposed to AgNO3 at 0.303 ± 0.017 μg silver/L (46.9% as Ag+), in the absence of food, in moderately hard synthetic water under static conditions for up to 48 h. Results from accumulation experiments demonstrated that silver body burden was inversely related to body mass. Daphnids exposed to silver exhibited ionoregulatory disturbance, which was characterized by decreases in whole-body sodium concentration. This ionoregulatory disturbance was explained, at least in part, by a competitive inhibition of the whole-body sodium uptake (six- to sevenfold increase in the Michaelis constant with no change in maximal velocity), which was complete by 1 h of exposure, and resulted in approximately 40% inhibition of sodium influx from the water. A rapidly developing inhibition of whole-body Na+,K+-dependent adenosine triphosphatase (Na+,K+-ATPase) activity, significant by 2 h and complete at 90% blockade by 12 h, also was observed during exposure to AgNO3. Therefore, these findings clearly demonstrate that the key mechanism involved in acute Ag+ toxicity in D. magna, the most sensitive freshwater organism tested to date, resembles that described for freshwater fish— that is, inhibition of active sodium uptake by blockade of Na+,K+-ATPase. Furthermore, the results showed that Na+,K+-ATPase inhibition was directly related to silver accumulation in the whole body of D. magna. However, the nature of the sodium uptake inhibition (competitive vs noncompetitive in fish) and the fact that whole-body chloride concentration was not disturbed in daphnids was different from fish. With regard to the biotic ligand model (BLM) for silver, our results yielded a log K value of about 8.9. However, the current version of the BLM uses a rainbow trout log K value (7.3) but achieves the correct sensitivity of the model for daphnids by reducing the saturation of toxic sites needed to cause toxicity. An alternative way may be to use the log K value derived from the present results.
Susceptibility of black fly larvae (Diptera: Simuliidae) to lawn-care insecticides individually and as mixtures
Authors: Overmyer Jay P. , Armbrust Kevin L. , Noblet Ray 
Published: March 2010

AbstractUrban and suburban watersheds have the potential to be highly impacted by chemicals, especially insecticides to control insect pests on lawns, ornamental plants, and home gardens. Three of the most common lawn-care insecticides detected in urban watersheds, carbaryl, chlorpyrifos, and malathion, have been evaluated using an acute orbital shaker toxicity test to determine their respective concentrations that produce 50% mortality (LC50) in Simulium vittatum Zetterstedt cytospecies IS-7 larvae. Results of the 48-h LC50 tests show chlorpyrifos to be the most toxic to black fly larvae (LC50 = 0.28 μg/L) followed by carbaryl (LC50 = 23.72 μg/L) and malathion (LC50 = 54.20 μg/L). These insecticides were also tested as binary and ternary mixtures using the toxic unit (TU) approach. Toxicity was shown to be greater than additive for the ternary mixture of chlorpyrifos—carbaryl—malathion (LC50 = 0.56 TU) and the binary mixtures of chlorpyrifos—malathion (LC50 = 0.72 TU) and carbaryl-malathion (LC50 = 0.78 TU). The binary combination of chlorpyrifos and carbaryl was shown to be additive (LC50 = 0.98 TU). These results indicate that aquatic invertebrate populations in urban and suburban streams may experience a higher-than-expected increase in toxicity-related effects when all three chemicals are present in the waterway.
Acute-to-chronic species sensitivity distribution extrapolation
Authors: Duboudin Cédric , Ciffroy Philippe , Magaud Hélène 
Published: March 2010

Abstract
Seeking to make greater use of available data for risk assessment of substances, we constructed, for the situation in which chronic data are limited or even nonexistent but acute data are relatively large, an acute to chronic transformation (ACT) methodology based on the concept of species sensitivity distributions (SSDs). This ACT methodology uses a comparison of acute and chronic SSDs, separately for vertebrate data (with 22 substances) and for invertebrate data (with 15 substances). Rather than comparing an acute toxicity value with a chronic value, as when calculating an acute to chronic ratio (ACR), samples of acute and chronic data corresponding to the same category of species were compared. Starting from a sample of acute data, the ACT methodology showed relationships that enable the creation of a sample of predicted chronic values. This sample can then be used to calculate a predicted chronic hazardous concentration potentially affecting 5% of species (HC5%), just as with a sample of real chronic toxicity values. This ACT approach was tested on 11 substances. For each substance, the real chronic HC5% and the predicted chronic HC5% were calculated and compared. The ratio between chronic HC5% and ACT HC5% was, on average, 1.6 and did not exceed 4.4 for the 11 substances studied.
Effects of egg order on organic and inorganic element concentrations and egg characteristics in tree swallows,Tachycineta bicolor
Authors: Custer Christine M. , Gray Brian R. , Custer Thomas W. 
Published: March 2010

AbstractThe laying order of tree swallow eggs was identified from the Housatonic River, Berkshire County, Massachusetts, USA, and eggs were chemically analyzed individually to document possible effects of laying order on organic contaminant and inorganic element concentrations. Effects of laying order on other parameters such as egg weight, size, and lipid and moisture content also were assessed. Some effects of egg order on total polychlorinated biphenyls (PCBs) were detected, but the effect was not uniform across individual females or between years. In 2004, clutches with higher total PCBs tended to have concentrations decline across egg order, whereas clutches with lower concentrations of PCBs tended to increase across egg order. In contrast, in 2005, there was a tendency for concentrations to increase across egg order. Polychlorinated biphenyl concentrations were highly variable within and among clutches in both years. The directionality of egg order associations (i.e., slopes) for trace elements was element dependent, was positive for Mn and Zn, was negative for B, and had no slope for Cr. Whole egg weight increased across egg order. Percentage lipid was variable within a clutch, with no pattern common across all females. Percentage lipid was also correlated with organic contaminant concentration. In highly contaminated environments, higher lipid content could have the unanticipated corollary of having higher concentrations of lipophilic contaminants such as PCBs. To reduce the effect of high variation within a clutch when assessing contamination exposure, it is recommended that two eggs per clutch be collected and pooled for chemical analysis. We further recommend that, as long as the two eggs are randomly collected, the additional effort needed to identify and collect specific eggs is not warranted. Environ. Toxicol. Chem. 2010;29:909–921. © 2009 SETAC
Mercury concentrations in landlocked Arctic char (Salvelinus alpinus) from the Canadian Arctic. Part II: Influence of lake biotic and abiotic characteristics on geographic trends in 27 populations
Authors: Gantner Nikolaus , Muir Derek C. , Power Michael , Iqaluk Deborah , Reist James D. , Babaluk John A. , Meili Markus , Borg Hans , Hammar Johan , Michaud Wendy , Dempson Brian , Solomon Keith R. 
Published: March 2010

Abstract
Among-lake variation in mercury (Hg) concentrations in landlocked Arctic char was examined in 27 char populations from remote lakes across the Canadian Arctic. A total of 520 landlocked Arctic char were collected from 27 lakes, as well as sediments and surface water from a subset of lakes in 1999, 2002, and 2005 to 2007. Size, length, age, and trophic position (δ15N) of individual char were determined and relationships with total Hg (THg) concentrations investigated, to identify a common covariate for adjustment using analysis of covariance (ANCOVA). A subset of 216 char from 24 populations was used for spatial comparison, after length-adjustment. The influence of trophic position and food web length and abiotic characteristics such as location, geomorphology, lake area, catchment area, catchment-to-lake area ratio of the lakes on adjusted THg concentrations in char muscle tissue were then evaluated. Arctic char from Amituk Lake (Cornwallis Island) had the highest Hg concentrations (1.31 µg/g wet wt), while Tessisoak Lake (Labrador, 0.07 µg/g wet wt) had the lowest. Concentrations of THg were positively correlated with size, δ15N, and age, respectively, in 88, 71, and 58% of 24 char populations. Length and δ15N were correlated in 67% of 24 char populations. Food chain length did not explain the differences in length-adjusted THg concentrations in char. No relationships between adjusted THg concentrations in char and latitude or longitude were found, however, THg concentrations in char showed a positive correlation with catchment-to-lake area ratio. Furthermore, we conclude that inputs from the surrounding environment may influence THg concentrations, and will ultimately affect THg concentrations in char as a result of predicted climate-driven changes that may occur in Arctic lake watersheds. Environ. Toxicol. Chem. 2010;29:633–643. © 2009 SETAC
A simple model to estimate monthly forest evapotranspiration in Japan from monthly temperature
Authors: Komatsu Hikaru , Kume Tomonori , Otsuki Kyoichi 
Published: March 2010

AbstractThe estimation of evapotranspiration (E) in forested areas is required for various practical purposes (e.g. evaluation of drought risks) in Japan. This study developed a model that estimates monthly forest E in Japan with the input of monthly temperature (T). The model is based on the assumptions that E equals the equilibrium evaporation rate (Eeq) and that Eeq is approximated by a function of T. The model formulates E as E (mm month−1) = 3·48 T ( °C) + 32·3. The accuracy of the model was examined using monthly E data derived using short‐term water balance (WB) and micrometeorological (M) methods for 15 forest sites in Japan. The model estimated monthly E more accurately than did the Thornthwaite and Hamon equations according to regression analysis of the estimated E and E derived using the WB and M methods. Although the model tended to overestimate monthly E, the overestimation could be reduced by considering the effect of precipitation on E. As T data are commonly available all over Japan, the model would be a useful tool to estimate forest E in Japan. Copyright © 2010 John Wiley & Sons, Ltd.
The temporal trends of reference evapotranspiration and its sensitivity to key meteorological variables in the Yellow River Basin, China
Authors: Liu Qiang , Yang Zhifeng , Cui Baoshan , Sun Tao 
Published: March 2010

AbstractThe temporal trends of reference evapotranspiration (ETref) reflect the combined effects of radiometric and aerodynamic variables, such as global solar radiation (Rs), wind speed, relative humidity and air temperature. The temporal trends of annual ETref during 1961–2006 calculated by Penman‐Monteith method were explored and the underlying causes for these trends were analysed in the Yellow River Basin (YRB). The contributions of key meteorological variables to the temporal trend of ETref were detected using the detrended method and then sensitivity coefficients of ETref to meteorological variables were determined. For ETref, positive trends in the upper, middle and whole of YRB, and significant negative trend (P = 0·05) in the lower basin were obtained by the linear fitted model. Significant increasing trend (P = 0·05) in air temperature and decreasing trend in relative humidity were the main causes for the increasing trends of ETref in the upper, middle and whole basins. For the whole basin, the increasing trend of ETref was mainly caused by the significant increase (P = 0·05) in air temperature and to a lesser extent by a decrease in the relative humidity, decreasing trends of Rs and wind speed reduced ETref. The spatial distribution of sensitivity coefficients addressed that the sensitive regions for ETref response to the changes of the four meteorological variables are different in the YRB. The sensitive region lay in the upper basin for Rs, the northwest portion of the middle basin for wind speed, the south portion of YRB for relative humidity and the west portion of the upper basin and the north portion of the middle basin for air temperature. In general, Rs was the most sensitive variable for ETref, followed by relative humidity, air temperature and wind speed in the basin scale. Copyright © 2010 John Wiley & Sons, Ltd.
Diversification of rural livelihood strategies and its effect on local landscape restoration in the semiarid hilly area of the Loess Plateau, China
Authors: Wang L. , Zhang J.‐L. , Liu L.‐M. 
Published: March 2010

AbstractThis study is about the diversification of livelihood strategies and the interaction of farmers' livelihood with landscape change in Zhongzhuang small watershed, Pengyang County in Ningxia Autonomous region located in the Loess Plateau, western China. Farmers' livelihoods and landscape patterns during 1978–2007 in Zhongzhuang were analysed. In different stages, diverse limiting factors were discovered behind the diversification process of livelihood strategies. Before 1978, ‘planned economy’, ‘production team organization’, strict ‘household registration system’ and the scarcity of livelihood assets were the main factors restricting the diversification of livelihood strategies. From 1978 to 1993, the reform and open policy provided opportunities for local people to diversify their livelihood strategies, but livelihood strategies based on crop production still took an important role in their life. From 2000 to 2007, national policies brought assistance to help local farmers diversify their agricultural activities. However, the insufficient and incomplete credit and insurance market and lack of skill were the main factors constraining non‐farm activity diversification. Meanwhile, through analysis of the links between livelihood strategies diversification and landscape pattern change, we found that diversification of farmers' livelihoods contributed to the recovery of the landscape. Finally, using this relationship, steps for future landscape restoration is proposed, which provide a new view of landscape restoration research in the Loess Plateau. Copyright © 2010 John Wiley & Sons, Ltd.
Adaptive styles in elite collegiate athletes: the role of activation and self‐regulation
Authors: Steiner Hans , Denny Katherine , Stemmle Pascale 
Published: March 2010

AbstractThe present study examined the interaction of emotional activation and self‐regulation in elite collegiate athletes. We hypothesized that athletes would report higher levels of self‐restraint, repressive defensiveness and denial of distress, but lower levels of distress than non‐athletes. Participants were composed of 461 collegiate athletes and 61 age‐ and gender‐matched non‐athletes from Stanford University. Social‐emotional adjustment and personality were assessed with the Weinberger Adjustment Inventory. Results indicate significant differences between athletes and non‐athletes. Athletes report lower levels of distress, higher levels of self‐restraint, repressive defensiveness and denial of distress. Logistic regressions assessed the important predictors of athlete status. Age, denial of distress and responsibility proved to be the most significant indicators of athlete status. Data can be interpreted in at least two ways: (1) athletes are better at dealing with pressure and therefore report lower levels of distress; or (2) athletes report lower distress because they utilize high levels of repressive defensiveness and denial of distress. Utilizing non self‐report methods would further clarify this question and would provide a deeper understanding of personality traits in athletes. Copyright © 2010 John Wiley & Sons, Ltd.
Psychosocial treatment refusal in personality disorder: a comparative study
Authors: Chiesa Marco , Martino Francesca , Pozzi Euro 
Published: March 2010

AbstractThere is a paucity of research concerning the identification of features implicated in treatment refusal by personality disorder. This study aims to identify clinical factors that may affect treatment uptake to a specialist psychosocial programme for personality disorder. Following a lengthy assessment, 39 patients (out of a total of 60 referrals) were offered entry to the programme. Fourteen patients who did not take up the offer of treatment and 25 patients who started the programme are compared on a number of demographic, diagnostic and clinical variables, including severity of presentation and subjective experience of the assessment process. The results show that, relative to non‐refusers, refusers were significantly younger, single, had a higher frequency of borderline personality disorder (BPD), experienced a less satisfactory relationship with the assessing clinician and had lower treatment expectations. Several dimensions measuring severity of presentation did not make a significant contribution to treatment uptake. A logistic regression analysis showed that assessment‐related variables total score and BPD were significant predictors of treatment refusal. The low sample size and the specialist nature of the service are important limitations with regard to the generalizability of the findings. Copyright © 2010 John Wiley & Sons, Ltd.
The β‐silicon effect. 4: substituent effects on the solvolysis of 1‐alkyl‐2‐(aryldimethylsilyl)ethyl trifluoroacetates
Authors: Fujiyama Ryoji , Alam Md. Ashadul , Shiiyama Aiko , Munechika Toshihiro , Fujio Mizue , Tsuno Yuho 
Published: March 2010

AbstractSolvolysis rates of 2‐(aryldimethylsilyl)‐1‐methylethyl and 2‐(aryldimethylsilyl)‐1‐tert‐butylethyl trifluoroacetates were determined conductimetrically in 60% (v/v) aqueous ethanol. The effects of aryl substituents at the silicon atom on the solvolysis rates at 50 °C were correlated with $\bar {\sigma }$ parameters of r+ = 0.15 with the Yukawa–Tsuno equation, giving ρ values of −1.5 for both secondary α‐Me and α‐tert‐Bu systems. The ρ values for those secondary systems are less negative than −1.75 for the 2‐(aryldimethylsilyl)ethyl system that proceeds by the Eaborn (non‐vertical) mechanism, while they are distinctly more negative than −0.99 for 2‐(aryldimethylsilyl)‐1‐phenylethyl system that should proceed by the Lambert (vertical) mechanism. There was a fairly linear relationship between the reaction constants (ρ) for the β‐silyl substituent effects and the solvolysis reactivities for a series of β‐silyl substrates. The solvolyses of the α‐Me and tert‐Bu substrates proceed through the transition state (TS) with an appreciable degree of the β‐silyl participation, close to the Eaborn (non‐vertical) TS rather than to the Lambert (vertical) TS. Copyright © 2010 John Wiley & Sons, Ltd.
What is the role of friends when contributing care at the end of life? Findings from an Australian population study
Authors: Burns Catherine M. , Abernethy Amy P. , Leblanc Thomas W. , Currow David C. 
Published: March 2010

AbstractPurpose: To examine the role of friends as caregivers of people with terminal illness.Method: Piloted questions were included in the 2001–2007 random face‐to‐face annual health surveys of 23 588 South Australians on the death of a loved one, caregiving provided, and characteristics of the caregiver and deceased individual. The survey was representative of the population by age, gender, and region of residence. Analyses focused on friends of the deceased loved one, providing daily or intermittent ‘hands on’ care. Logistic regression assessed predictors of home death.Results: Daily ‘hands on’ carers were much more likely to be female and aged between 55 and 64; there was also a younger (<age 45) cohort of intermittent ‘hands on’ caregivers. When friends were carers, the deceased was more frequently younger (<age 65) and had cancer (p⩽0.001). Almost a third of caregiving friends were actively involved in care for >12 months. Home deaths were more frequent (32%, p=0.014) when friends were carers, and the rate of palliative care use was higher than when family/others provided care (70 vs 61%). Regression analyses confirmed friends as caregivers as a predictor of home death (OR 1.73: 95%, CI 1.15–2.87).Conclusion: Friends contribute their caregiving: A cohort of younger caregivers may reflect changing social mores as the extended family shrinks and people turn to friendship networks for care and support at the end of life. Copyright © 2010 John Wiley & Sons, Ltd.