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The origin of the populations used in ecotoxicological bioassays (from nature (wild populations) or from cultures (laboratory populations)) could have a key influence on the sensitivity of the tested species to different toxicants. However, the available information on this subject is scarce. To assess the likely influence of the population origin (wild vs. laboratory) of species–genus on the toxicant tolerance, we performed a quantitative review of the ECOTOX database, from which we collected the effective concentrations for a wide range of compounds (metals and organics), endpoints, and exposure times. We found a general trend of lower sensitivity of wild populations to toxicants than laboratory populations, although sensitivity was dependent on species and toxicant groups. This suggests that the results of bioassays with laboratory populations may overestimate the toxicity of most of the compounds. Our study highlights the relevance of the origin of the populations in the determination of the sensitivity of species to toxicants. This study also warns about the biases in the species and toxicants used in ecotoxicology, which may lead to an underrepresentation of the biodiversity and the toxicological context of aquatic ecosystems.

Behavioral endpoints are important parameters to assess the effects of toxicants and other stressors on natural ecosystems. The relevance of these parameters has caused a rise in their use in aquatic ecotoxicology. However, abiotic and biotic parameters may interact causing changes in the behavioral responses. Among those parameters, starvation of animals is a factor that is usually applied in ecotoxicological short-term bioassays. This could alter animal behavior, along with the toxicant. Therefore, the study of the effects of starvation on baseline behaviors of invertebrates is a relevant issue. This study assessed the behavior of the aquatic snail Potamopyrgus antipodarum under a combination of four treatments: (1) animals normally fed (control treatment), (2) starved animals, (3) animals normally fed and exposed to a high conductivity, and (4) starved animals exposed to a high conductivity. The behavior activity of snails was monitored for 14 days. Results show that animals of the second treatment (starved animals) increased their activity. On the contrary, animals of the third and fourth treatments reduced their activity. Animals from the control treatment showed an activity in between starved animals and animals exposed to high conductivity (both starved and normally fed). These results show that starvation increases the snail activity, but under another environmental stressor (i.e., high conductivity), this trend was reversed. The influence of starvation on behavior should be taken into account in the development of behavioral bioassays.

Microplastics are ubiquitous in aquatic ecosystems. They can be found at the surface, in the water column, and in sediments. Multiple negative impacts of microplastics on aquatic organisms have been reported, with most studies focusing on marine ecosystems. However, the effects of microplastics on freshwater ecosystems have been less studied, with a few studies focusing on benthic invertebrates. In this study, we exposed the New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) to an environmental range of concentrations of polystyrene microparticles (size range from 0.01 to 514 µm at 100, 500, and 1000 mg microplastics/kg dry weight (dw) of sediment) and two supra-environmental concentrations (2000 and 4000 mg/kg dw sediment). The impacts of the exposure to microplastics on mortality, behavior, and reproduction were assessed at long-term exposure (31 days). Mortality and reproduction were not significantly affected by microplastics. On the contrary, most of the microplastic treatments altered the behavior, causing a significant increase in reaction time compared with controls (0 mg microplastics/kg dw sediment). The highest concentration (4000 mg/kg) did not have an impact on the reaction time over the experimental period compared with controls. To our knowledge, this study is the first to assess the effects of microplastics on the behavior of the aquatic snail P. antipodarum. Our results showed that at environmental concentrations, the behavior of P. antipodarum was the most sensitive variable to the adverse effects of polystyrene microplastics.

Cells continually sample their mechanical environment using exquisite force sensors such as talin, whose folding status triggers mechanotransduction pathways by recruiting binding partners. Mechanical signals in biology change quickly over time and are often embedded in noise; however, the mechanics of force-sensing proteins have only been tested using simple force protocols, such as constant or ramped forces. Here, using our magnetic tape head tweezers design, we measure the folding dynamics of single talin proteins in response to external mechanical noise and cyclic force perturbations. Our experiments demonstrate that talin filters out external mechanical noise but detects periodic force signals over a finely tuned frequency range. Hence, talin operates as a mechanical band-pass filter, able to read and interpret frequency-dependent mechanical information through its folding dynamics. We describe our observations in the context of stochastic resonance, which we propose as a mechanism by which mechanosensing proteins could respond accurately to force signals in the naturally noisy biological environment.

This article deals with the comparative analysis of current cable force monitoring techniques. In addition, the experience of three cable stress monitoring techniques during the construction phase is included: (a) the installation of load cells on the active anchorages of the cables, (b) the installation of unidirectional strain gauges, and (c) the evaluation of stresses in cables applying the vibrating wire technique by means of the installation of accelerometers. The main advantages and disadvantages of each technique analysed are highlighted in the Construction Process context of the Tajo Viaduct, one of the most singular viaducts recently built in Spain.

Although advanced interatrial block (aIAB) is an established electrocardiographic phenotype, its prevalence, incidence, and prognostic significance in the general population are unclear. We examined the prevalence, incidence, and prognostic significance of aIAB in 14,625 (mean age = 54 ± 5.8 years; 26% black; 55% female) participants from the Atherosclerosis Risk in Communities (ARIC) study. aIAB was detected from digital electrocardiograms recorded during 4 study visits (1987 to 1989, 1990 to 1992, 1993 to 1995, and 1996 to 1998). Risk factors for the development of aIAB were examined using multivariable Poisson regression models with robust variance estimates. Cox regression was used to compute hazard ratios and 95% CIs for the association between aIAB, as a time-dependent variable, and atrial fibrillation (AF). AF was ascertained from study electrocardiogram data, hospital discharge records, and death certificates thorough 2010. A total of 69 participants (0.5%) had aIAB at baseline, and 193 (1.3%) developed aIAB during follow-up. The incidence for aIAB was 2.27 (95% CI 1.97 to 2.61) per 1,000 person-years. Risk factors for aIAB development included age, male gender, white race, antihypertensive medication use, low-density lipoprotein cholesterol, body mass index, and systolic blood pressure. In a Cox regression analysis adjusted for sociodemographics, cardiovascular risk factors, and potential confounders, aIAB was associated with an increased risk for AF (hazard ratio 3.09, 95% CI 2.51 to 3.79). In conclusion, aIAB is not uncommon in the general population. Risk factors for developing aIAB are similar to those for AF, and the presence of aIAB is associated with an increased risk for AF.

The Internet of Things (IoT) brings plenty of opportunities to enhance society’s activities, from improving a factory’s production chain to facilitating people’s household tasks. However, it has also brought new security breaches, compromising privacy and authenticity. IoT devices are vulnerable to being accessed from the Internet; they lack sufficient resources to face cyber-attack threats. Keeping a balance between access control and the devices’ resource consumption has become one of the highest priorities of IoT research. In this paper, we evaluate an access control architecture based on the IAACaaS (IoT application-Scoped Access Control as a Service) model with the aim of protecting IoT devices that communicate using the Publish/Subscribe pattern. IAACaaS is based on the OAuth 2.0 authorization framework, which externalizes the identity and access control infrastructure of applications. In our evaluation, we implement the model using FIWARE Generic Enablers and deploy them for a smart buildings use case with a wireless communication. Then, we compare the performance of two different approaches in the data-sharing between sensors and the Publish/Subscribe broker, using Constrained Application Protocol (CoAP) and Hypertext Transfer Protocol (HTTP) protocols. We conclude that the integration of Publish/Subscribe IoT deployments with IAACaaS adds an extra layer of security and access control without compromising the system’s performance.

To define the incidence and cumulative risk of atrial fibrillation (AF) in a population-based cohort of whites and African Americans. African-Americans reportedly have a lower risk of AF than whites despite their higher exposure to AF risk factors. However, precise estimates of AF incidence in African Americans have not been previously published. We studied the incidence of AF in the Atherosclerosis Risk in Communities (ARIC) study, which has followed up 15,792 men and women 45 to 65 years of age at baseline from 4 communities in the United States since 1987. Atrial fibrillation cases were identified from electrocardiograms conducted at baseline and 3 follow-up visits, and from hospitalizations and death certificates through the end of 2004. During follow-up, 1,085 new cases of AF were identified (196 in African Americans, 889 in whites). Crude incidence rates of AF were 6.7, 4.0, 3.9, and 3.0 per 1,000 persons per year in white men, white women, African-American men, and African-American women, respectively. Increasing age was exponentially associated with an elevated risk of AF. Compared to whites, African-Americans had a 41% (95% CI: 8%-62%) lower age- and sex-adjusted risk of being diagnosed with AF. The cumulative risk of AF at 80 years of age was 21% in white men, 17% in white women, and 11% in African-American men and women. In this population-based cohort, African Americans presented a lower risk of AF than whites. Still, the burden of AF among the former is substantial, with 1 in 9 receiving a diagnosis of AF before 80 years of age.

Aims Plant invasions generally lead to mixtures between native and non-native litter. We assess the interactions between leaf litters from two invasive non-native trees ( Robinia pseudoacia or Ailanthus altissima ) and the native Populus alba on litter decomposition, nutrient release and soil properties along two gradients of invasion. Methods Microcosms with field-collected soil covered by varying proportions of native and non-native litter simulated the two invasion gradients. We assessed the proportion of remaining litter mass and nutrient mass (N, P, C), and soil C, N-NO 3 − , total N, and pH, five times throughout a period of 11 months. Observed values were compared to the expected values on the assumption of no interactions. Results Litter mass and C mass decayed slower in Robinia and faster in Ailanthus than in Populus . The three species immobilized N and P. Soil properties did not differ across pure litters. Both litter mixture gradients showed additive or antagonistic interactions on litter decomposition, whereas N and P mass were equal or higher than expected. The proportion of non-native litter in the mixture had non-linear effects on most variables, suggesting that the impact of these non-native trees on litter decay levels off or even declines as they become more abundant. Conclusion The impacts of Ailanthus and Robinia litter on soil processes should not be derived from single species experiments, both due to non-additive effects and to non-linear responses to litter abundance.

One of the aims of ecotoxicology is the assessment of the effects of chemicals on the ecosystems. Bioassays assessing lethality are frequently used in ecotoxicology, however they usually employ supra-environmental toxic concentrations. Toxicity tests employing behavioral endpoints may present a balance between simplicity (i.e., laboratory bioassays) and complexity (i.e., relevant ecological effects). The aim of this study was to develop a feeding behavioral bioassay with the aquatic snail, Potamopyrgus antipodarum, which included a 2 days exposure to cadmium, followed by a 9 days post-exposure observational period. Several behavioral feeding endpoints were monitored, including percentage of actively feeding animals, percentage of animals in food quadrants and a mobility index. The percentage of actively feeding animals was reduced by the four cadmium treatments (0.009, 0.026, 0.091 and 0.230 mg Cd/L) with the stronger effect in the highest concentration. The two highest cadmium concentrations significantly reduced the percentage of animals in food quadrants and the mobility index. Therefore, the percentage of actively feeding animals was the most sensitive endpoint to cadmium toxicity as the four cadmium concentrations caused a significant decrease in this endpoint. It is concluded that feeding behavior is a useful endpoint to detect the exposure of aquatic snails to cadmium.