Paying the pipers: mitigating the impact of anticoagulant rodenticides on predators and scavengers

Anticoagulant rodenticides, mainly second-generation forms, or SGARs, dominate the global market for rodent control. Introduced in the 1970s to counter genetic resistance in rodent populations to first-generation compounds such as warfarin, SGARs are extremely toxic and highly effective killers. However, their tendency to persist and accumulate in the body has led to the widespread contamination of terrestrial predators and scavengers. Commercial chemicals that are classified by regulators as persistent, bio-accumulative, and toxic (PBT) chemicals and that are widely used with potential environmental release, such as dichloro-diphenyl-trichloroethane (DDT) or polychlorinated biphenyls (PCBs), have been removed from commerce. However, despite consistently failing ecological risk assessments, SGARs remain in use because of the demand for effective rodent-control options and the lack of safe and humane alternatives. Although new risk-mitigation measures for rodenticides are now in effect in some countries, the contamination and poisoning of nontarget wildlife are expected to continue. Here, we suggest options to further attenuate this problem

Surface coating and particle size are main factors explaining the transcriptome-wide responses of the earthworm Lumbricus rubellus to silver nanoparticles

Due to the unique properties of differently sized and coated silver nanoparticles (AgNPs), they are used in important industrial and biomedical applications. However, their environmental fate in soil ecosystems and potential mechanisms of toxicity remain elusive, especially at the level of transcriptional regulation. We investigated the transcriptome-wide responses of the earthworm Lumbricus rubellus exposed to nine AgNPs differing in surface coating/charge (bovine serum albumin/negative AgNP_BSA, chitosan/positive AgNP_Chit, and polyvinylpyrrolidone/neutral AgNP_PVP) and sizes (20, 35 and 50 nm) at concentrations close to the EC50 value related to reproduction. AgNO3 was used in two concentrations to benchmark the AgNP effects against those of the Ag salt. A correlation was observed between the number of differentially expressed genes (DEGs) and Ag internal body concentration. Only metallothionein was regulated by all treatments. Medium sized AgNPs caused the most pronounced transcriptional responses, while AgNO3 affected the transcriptome less. Medium sized AgNP_BSA exposure caused the most extensive transcriptional responses with 684 DEGs. Gene ontology enrichment analysis of medium sized AgNP_BSA affected DEGs revealed that mitochondrial electron transport, autophagy and phagocytosis, mesoderm and heart development and microtubule organisation were affected. This was also confirmed by gene set enrichment for KEGG pathway analysis, indicating that phagocytosis, autophagy and signalling pathways related to mesoderm formation were significantly up regulated. All AgNP_BSA and AgNP_PVP exposures caused severe down regulation of ribosomal translation, suggesting that the high energy-demanding protein synthesis process is inhibited. Our data confirm the mechanisms previously identified among other animal models and human cell lines. To conclude, coating formulation and particle size severely impact transcriptional responses at a particular nanoparticle size, suggesting diverse mechanistic responses depending on the coating type

Legacy and Emerging Persistent Organic Pollutants in Antarctic Benthic Invertebrates near Rothera Point, Western Antarctic Peninsula

The levels of pollutants in polar regions is gaining progressively more attention from the science community. This is especially so for pollutants that persist in the environment and can reach polar latitudes via a wide range of routes, such as persistent organic pollutants (POPs). In this study samples of Antarctic marine benthic organisms were analysed for legacy and emerging POPs to comprehensively assess the current POPs concentrations in Antarctic benthos and infer the potential sources of the pollutants. Specimens of 5 different benthic invertebrate species were collected in 2 distinct locations near the Rothera Research station (67°35'8"S and 68°7'59"W). Any impact of the nearby Rothera Station as a local source of pollution appeared to be negligible. The most abundant chemicals detected were HCB and BDE-209, reaching the highest concentrations in limpets and urchins, followed by sea stars, ascidians and sea cucumbers. The relative congener patterns of PCBs and PBDEs were almost the same in all species. Some chemicals (e.g. Heptachlor, Oxychlordane and Mirex) were detected in the Antarctic invertebrates for the first time. Statistical methods revealed that the distribution of the POPs is not only driven by the feeding traits of the species, but also by the physico-chemical properties of the individual compounds. Benthic invertebrates are excellent indicators of the contaminant patterns of inshore Antarctic ecosystems

Nonergodicity in Load and Recovery:Group Results Do Not Generalize to Individuals

PURPOSE: The study of load and recovery gained significant interest in the last decades, given its important value in decreasing the likelihood of injuries and improving performance. So far, findings are typically reported on the group level, whereas practitioners are most often interested in applications at the individual level. Hence, the aim of the present research is to examine to what extent group-level statistics can be generalized to individual athletes, which is referred to as the "ergodicity issue." Nonergodicity may have serious consequences for the way we should analyze, and work with, load and recovery measures in the sports field. METHODS: The authors collected load, that is, rating of perceived exertion × training duration, and total quality of recovery data among youth male players of a professional football club. This data were collected daily across 2 seasons and analyzed on both the group and the individual level. RESULTS: Group- and individual-level analysis resulted in different statistical outcomes, particularly with regard to load. Specifically, SDs within individuals were up to 7.63 times larger than SDs between individuals. In addition, at either level, the authors observed different correlations between load and recovery. CONCLUSIONS: The results suggest that the process of load and recovery in athletes is nonergodic, which has important implications for the sports field. Recommendations for training programs of individual athletes may be suboptimal, or even erroneous, when guided by group-level outcomes. The utilization of individual-level analysis is key to ensure the optimal balance of individual load and recovery

Stress behaviour and physiology of developing Arctic barnacle goslings (<i>Branta leucopsis</i>) is affected by legacy trace contaminants

Natural populations are persistently exposed to environmental pollution, which may adversely impact animal physiology and behaviour and even compromise survival. Responding appropriately to any stressor ultimately might tip the scales for survival, as mistimed behaviour and inadequate physiological responses may be detrimental. Yet effects of legacy contamination on immediate physiological and behavioural stress coping abilities during acute stress are virtually unknown. Here, we assessed these effects in barnacle goslings (Branta leucopsis) at a historical coal mine site in the Arctic. For three weeks we led human-imprinted goslings, collected from nests in unpolluted areas, to feed in an abandoned coal mining area, where they were exposed to trace metals. As control we led their siblings to feed on clean grounds. After submitting both groups to three well-established stress tests (group isolation, individual isolation, on-back restraint), control goslings behaved calmer and excreted lower levels of corticosterone metabolites. Thus, legacy contamination may decisively change stress physiology and behaviour in long-lived vertebrates exposed at a young age.</p

Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts

Metal transfer to sediments, invertebrates and fish following waterborne exposure to silver nitrate or silver sulfide nanoparticles in an indoor stream mesocosm

The fate of engineered nanomaterials in ecosystems is unclear. An aquatic stream mesocosm explored the fate and bioaccumulation of silver sulfide nanoparticles (AgS NPs) compared to silver nitrate (AgNO). The aims were to determine the total Ag in water, sediment and biota, and to evaluate the bioavailable fractions of silver in the sediment using a serial extraction method. The total Ag in the water column from a nominal daily dose of 10 μg L of Ag for the AgNO or AgS NP treatments reached a plateau of around 13 and 12 μg L, respectively, by the end of the study. Similarly, the sediment of both Ag-treatments reached ~380 μg Ag kg, and with most of it being acid-extractable/labile. The biota accumulated 4–59 μg Ag g dw, depending on the type of Ag-treatment and organism. The oligochaete worm, Lumbriculus variegatus, accumulated Ag from the AgS exposure over time, which was similar to the AgNO treatment by the end of the experiment. The planarian, Girardia tigrina, and the chironomid larva, Chironomus riparius, showed much higher Ag concentrations than the oligochaete worms; and with a clearer time-dependent statistically significant Ag accumulation relative to the untreated controls. For the pulmonate snail, Physa acuta, bioaccumulation of Ag from AgNO and AgS NP exposures was observed, but was lower from the nano treatment. The AgNO exposure caused appreciable Ag accumulation in the water flea, Daphnia magna, but accumulation was higher in the AgS NP treatment (reaching 59 μg g dw). In the rainbow trout, Oncorhynchus mykiss, AgNO, but not AgS NPs, caused total Ag concentrations to increase in the tissues. Overall, the study showed transfer of total Ag from the water column to the sediment, and Ag bioaccumulation in the biota, with Ag from AgS NP exposure generally being less bioavailable than that from AgNO.This work was supported by the project NanoFASE (Nanomaterial Fate and Speciation in the Environment), financed by the European Union's Horizon 2020 research and innovation programme under grant agreement no 646002. RDH was partly supported by NanoHarmony under grant agreement 885931 in Horizon 2020 while redrafting the main text. PVS was awarded with a PhD grant (SFRH/BD/51571/2014) by FCT – Fundação para a Ciência e a Tecnologia. SL and PVS received additional financial support from FCT/MCTES, through national funds, to CESAM (UIDP/50017/2020+UIDB/50017/2020+ LA/P/0094/2020)

A schematic sampling protocol for contaminant monitoring in raptors

Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility. The present perspective introduces a schematic sampling protocol for contaminant monitoring in raptors. We provide guidance on sample collection with a view to increasing sampling capacity across countries, ensuring appropriate quality of samples and facilitating harmonization of procedures to maximize the reliability, comparability and interoperability of data. The here presented protocol can be used by professionals and volunteers as a standard guide to ensure harmonised sampling methods for contaminant monitoring in raptors

To continue or not to continue? Antipsychotic medication maintenance versus dose-reduction/discontinuation in first episode psychosis: HAMLETT, a pragmatic multicenter single-blind randomized controlled trial

BACKGROUND: Antipsychotic medication is effective for symptomatic treatment in schizophrenia-spectrum disorders. After symptom remission, continuation of antipsychotic treatment is associated with lower relapse rates and lower symptom severity compared to dose reduction/discontinuation. Therefore, most guidelines recommend continuation of treatment with antipsychotic medication for at least 1 year. Recently, however, these guidelines have been questioned as one study has shown that more patients achieved long-term functional remission in an early discontinuation condition-a finding that was not replicated in another recently published long-term study. METHODS/DESIGN: The HAMLETT (Handling Antipsychotic Medication Long-term Evaluation of Targeted Treatment) study is a multicenter pragmatic single-blind randomized controlled trial in two parallel conditions (1:1) investigating the effects of continuation versus dose-reduction/discontinuation of antipsychotic medication after remission of a first episode of psychosis (FEP) on personal and social functioning, psychotic symptom severity, and health-related quality of life. In total 512 participants will be included, aged between 16 and 60 years, in symptomatic remission from a FEP for 3-6 months, and for whom psychosis was not associated with severe or life-threatening self-harm or violence. Recruitment will take place at 24 Dutch sites. Patients are randomized (1:1) to: continuation of antipsychotic medication until at least 1 year after remission (original dose allowing a maximum reduction of 25%, or another antipsychotic drug in similar dose range); or gradual dose reduction till eventual discontinuation of antipsychotics according to a tapering schedule. If signs of relapse occur in this arm, medication dose can be increased again. Measurements are conducted at baseline, at 3, and 6 months post-baseline, and yearly during a follow-up period of 4 years. DISCUSSION: The HAMLETT study will offer evidence to guide patients and clinicians regarding questions concerning optimal treatment duration and when to taper off medication after remission of a FEP. Moreover, it may provide patient characteristics associated with safe dose reduction with a minimal risk of relapse. TRIAL STATUS: Protocol version 1.3, October 2018. The study is active and currently recruiting patients (since September 2017), with the first 200 participants by the end of 2019. We anticipate completing recruitment in 2022 and final assessments (including follow-up 3.5 years after phase one) in 2026. TRIAL REGISTRATION: European Clinical Trials Database, EudraCT number 2017-002406-12. Registered 7 J