Two-year monitoring of Cryptosporidium parvum and Giardia lamblia occurrence in a recreational and drinking water reservoir using standard microscopic and molecular biology techniques

Starting in 2006, a monitoring of Giardia lamblia and Cryptosporidium parvum occurrence was conducted for 2 years in the largest drinking water reservoir of Luxembourg (Esch-sur-S?re reservoir) using microscopy and qPCR techniques. Parasite analyses were performed on water samples collected from three sites: site A located at the inlet of the reservoir, site B located 18 km downstream site A, at the inlet of the drinking water treatment plant near the dam of the reservoir and site C where the finished drinking water is injected in the distribution network. Results show that both parasites are present in the reservoir throughout the year with a higher occurrence of G. lamblia cysts compared to C. parvum oocysts. According to our results, only 25% of the samples positive by microscopy were confirmed by qPCR. (Oo)cyst concentrations were 10 to 100 times higher at site A compared to site B and they were positively correlated to the water turbidity and negatively correlated to the temperature. Highest (oo)cyst concentrations were observed in winter. In contrast, no relationship between the concentrations of (oo)cysts in the reservoir and rain events could be established. Though a correlation has been observed between both parasites and faecal indicators in the reservoir, some discrepancies highlight that the latter do not represent a reliable tool to predict the presence/absence of these pathogenic protozoa. In summer 2007, the maximal risk of parasite infection per exposure event for swimmers in the reservoir was estimated to be 0.0015% for C. parvum and 0.56% for G. lamblia. Finally, no (oo)cysts could be detected in large volumes of finished drinking water.     

The effect of predation on artificial reef juvenile demersal fish species

There is a concern that artificial reefs (AR) may act purely as fishing aggregation devices. Predators attracted to ARs can influence the distribution and abundance of prey fish species. Determining the role of predators in AR is important in advancing the understanding of community interactions. This paper documents the effects of predation on fish assemblages of AR located near a coastal lagoon fish nursery. The Dicentrarchus labrax is a very opportunistic species preying on juveniles (0⁺ and 1⁺ age classes) of several demersal fish species on the ARs. Reef prey and sea bass abundance were negatively correlated. The mean numbers of prey per sea bass stomach increased with the increase of reef fish prey abundance, suggesting that predation has a significant influence, resulting in a decrease in prey abundance. Prey mortality (4–48%) of demersal reef fish associated species depends on bass density. Prey selection was related both with prey abundance and vulnerability. Results showed that D. labrax predation on AR-fish associated species can increase prey natural mortality. However, the role of bass predation on the ecological functioning of exploited ARs is not clear. There may be increases in local fishing yields due either to an increase in predator biomass through aggregation of sea bass attracted to ARs or to greater production. In contrast, predation on juveniles of economically important reef fish preys, especially the most frequent and abundant (Boops boops), can contribute to a decrease in recruitment to the fishery. Our results indicate that inter-specific interactions (predator–prey) are important in terms of conservation and management, as well as for the evaluation of the long-term effects of reef deployment. Thus, it is necessary to consider ecological interactions, such as predation, prior to the development and deployment of artificial habitats as a tool for rehabilitation.     

Association of benzene exposure with insulin resistance,SOD, and MDA as markers of oxidative stress in children and adolescents

Benzene is a ubiquitous environmental pollutant with various health effects. It is reported that benzene exposure might be associated with insulin resistance in elderly adults. The aim of this study is to investigate the association between urinary benzene metabolite, trans, trans-muconic acid (t,t-ma) and markers of oxidative stress and insulin resistance in children and adolescents. This cross-sectional study was conducted in 2017 among 86 children and adolescents, aged 6–18 years, living in Isfahan, Iran. t,t-ma was measured as urinary benzene metabolite and homeostasis model assessment (HOMA-IR) was determined as an index of insulin resistance. Moreover, malondialdehyde (MDA) and superoxide dismutase (SOD) were assessed as oxidative stress markers. We found significant association between insulin resistance, fasting blood glucose, and fasting blood insulin with t,t-ma (p values?=?0.002, 0.03, and 0.001, respectively). Results of this study indicate that benzene metabolite in higher concentrations in comparison with lower concentrations is associated with increased risk of insulin resistance. Moreover, after adjustment for age, sex, and household passive smoking, statistically significant increase were documented in SOD and MDA (4.49- and 3.54-fold, respectively) in intermediate levels of t,t-ma vs. low levels of t,t-ma (p values?=?0.01 and 0.034, respectively). To the best of our knowledge, this is the first study in its kind in the pediatric age group. It showed that benzene exposures, even in environmental levels, might be associated with insulin resistance and oxidative stress in children and adolescents. Further longitudinal studies are necessary to assess the clinical impacts of this finding.     

Identification of Potential Essential Fish Habitats for Skates Based on Fishers’ Knowledge

Understanding of spatio-temporal patterns of sensitive fish species such as skates (Rajidae) is essential for implementation of conservation measures. With insufficient survey data available for these species in Portuguese Continental waters, this study shows that fishery-dependent data associated with fishers’ knowledge can be used to identify potential Essential Fish Habitats (EFH) for seven skate species. Sites with similar geomorphology were associated with the occurrence of juveniles and/or adults of the same group of species. For example, sites deeper than 100 m with soft sediment include predominantly adults of Raja clavata, and are the habitat for egg deposition of this species. Raja undulata and R. microocellata are the more coastal species, preferring sand or gravel habitats, while coastal areas with rocks and sand seabed are potential nursery areas for R. brachyura, R. montagui and R. clavata. The main output of this study is the identification of preferential fishing sites enclosing potential EFH for some species, associated with egg-laying and nursery grounds. The location of these areas will be considered for future seasonal closures, and studies will be conducted to evaluate the biological and socio-economic impacts of such measures. As in the past, fishermen will collaborate in the process of evaluating those impacts, since they have practical and applied knowledge that is extremely valuable for evaluating the advantages and disadvantages of such closures. In conclusion, this study is a first contribution to the understanding and identification of EFH for skate species, associated with nursery and egg deposition sites, with direct application to management.     

Removal of Cr(VI) from aqueous solution using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid doped polypyrrole as adsorbent

Environmental Science and Pollution Research - Polypyrrole (PPy) conducting films, doped with 4-amino-3-hydroxynaphthalene sulfonic acid (AHNSA), were electrosynthesized by anodic oxidation of...     

Environmental influence on commercial fishery landings of small pelagic fish in Portugal

Small pelagic fishes are particularly abundant in areas with high environmental variability (zones of coastal upwelling and areas of tidal mixing and river discharge), and because of this, their abundance suffers large inter-annual and inter-decadal fluctuations. In Portugal, the most important species in terms of landings are European sardine, Atlantic horse mackerel and Atlantic chub mackerel. Small pelagic fish landings account for 62.8 % of the total fish biomass and represent 32.7 % of the economical value of all catches. We have investigated trends in landings of these small pelagic fishes and detected the effects of environmental factors in this fishery. In order to explain the variability of landings of small pelagic fishes, we have used official landings (1965–2012) for trawling and purse seine fisheries and applied generalized linear models, using the North Atlantic Oscillation index (NAO) (annual and winter NAO index), sea surface temperature (SST), wind data (strength and North–South and East–West wind components) and rainfall, as explanatory variables. Regression analysis was used to describe the relationship between landings and SST. The models explained between 50.16 and 51.07 % of the variability of the LPUE, with the most important factors being winter NAO index, SST and wind strength. The LPUE of European sardine and Atlantic horse mackerel was negatively correlated with SST, and LPUE of Atlantic chub mackerel was positively correlated with SST. The use of landings of three important species of small pelagic fishes allowed the detection of variations in landings associated with changes in sea water temperature and NAO index.     

Speed of call delivery is related to context and caller identity in Campbell’s monkey males

Call rate can be a salient feature in animal communication. Depending on the species, different psychological variables appear to influence call rates but the exact nature of these relationships remains poorly explored. Here, we demonstrate for free-ranging Campbell’s monkeys that the call rates of four different alarm series (termed H, K, K₊, and B series) vary systematically as a function of context, associated behaviour, and identity of the caller. K₊ series were given more rapidly to predation than non-predation events, K₊ and K series more rapidly to visual than auditory predator detection, and H series more rapidly while counterattacking an eagle than staying put. Finally, there were individual differences in B series, suggesting that call rate potentially provides listeners with cues about the caller’s anti-predator behaviour, event type experienced, and his identity.     

Experimental and numerical study of methylparaben decomposition in aqueous solution using the UV/H2O2 process

The present paper aims at presenting a kinetic model that is supposed to result in the decomposition of methylparaben in completely mixed batch reactor (CMBR) using the UV/H₂O₂ process. The proposed model incorporates photochemical, chemical reactions and their constant rates to formulate the overall kinetic rate expressions which are integrated into MATLAB. Thus, the changes in pH values during the process of oxidation are taken into consideration. In addition, the effects of hydrogen peroxide (HP) dosage, as well as the concentration of hydroxyl radicals, are examined. Accordingly, the pseudo-first-order rate constant, its variation as functions of HP concentration, incident UV-light intensity and the limitations of the adopted approach are discussed. In line with that, the authors provided evidence of the validity of the kinetic model through the exposure of previous experimental studies as reported in the literature review then through the evidence of the present experimental data.     

Time‐based differences in the effects of positive and negative affectivity on perceived supervisor support and organizational commitment among newcomers

Building on the broaden‐and‐build theory and research on the negativity bias, this study examines how trait affectivity, as a stable predisposition predicting the pattern of emotional responding, shapes newcomers' perceptions of supervisor support and experience of organizational commitment. Using latent growth modeling and data collected at four points in time from newcomers (N = 158), we found the initial level of perceived supervisor support to mediate a negative relationship between negative affectivity and the level of commitment. Moreover, although newcomers experienced a general decrease in perceived supervisor support and a related decrease in commitment, those with high positive affectivity experienced a weaker decrease in perceived supervisor support, which led to a weaker decrease in commitment. Incidentally, positive affectivity was also positively related to the initial level of commitment. Two post hoc studies indicated that positive and negative affectivity exerted their effects controlling for state affect and replicated the relationship between change in perceived support and commitment. We discuss how these findings inform our understanding of trait affectivity's influence on newcomers' work attitudes.     

Comparative study of plasma lead levels in the staff of Dandy Zinc Factory of Zanjan and in normal individuals

Pollution is a global problem which affects various human population functions. Despite the decline in plasma lead (Pb) levels among the general population during the past 20 years, this metal continues to be a public health concern for individuals with past and present exposures. The objective of this study was to determine blood lead levels (BPbL) in the staff of Dandy Zinc Company and compare them to control subjects. The test group included 40 staff of Dandy Zinc Company of Zanjan, while controls were selected from general population. Five milliliters of blood and plasma was sent to Atomic Energy Organization of Iran (AOEI) reference lab to measure BPbL by Flameless Atomic Absorption. BPbL in test group (16.6 + 8.18 µg dL^?1) was significantly higher than control (10.47 + 2.10 µg dL^?1). In both groups BPbL was significantly higher in smokers than non-smokers. Blood lead levels in molding workers were significantly higher than other workers. BPbL in exposed workers were directly related to duration of work and age. Data indicate Pb exposure was of significant magnitude to be a public health concern especially in zinc-and Pb-related industries.