Pesticide impacts are usually discussed in the context of applied amounts while disregarding the large but environmentally relevant variations in substance-specific toxicity. Here, we systemically ...interpret changes in the use of 381 pesticides over 25 years by considering 1591 substance-specific acute toxicity threshold values for eight nontarget species groups. We find that the toxicity of applied insecticides to aquatic invertebrates and pollinators has increased considerably-in sharp contrast to the applied amount-and that this increase has been driven by highly toxic pyrethroids and neonicotinoids, respectively. We also report increasing applied toxicity to aquatic invertebrates and pollinators in genetically modified (GM) corn and to terrestrial plants in herbicide-tolerant soybeans since approximately 2010. Our results challenge the claims of a decrease in the environmental impacts of pesticide use.
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•Water quality data (n > 8.3 mio) from 31 European countries (2001–2015).•Detection frequencies of organic contaminants (e.g. pesticides) increase over time.•Ecological thresholds are ...exceeded frequently in surface waters throughout Europe.•Ecological risks increase over time with pesticides being an important risk driver.•Monitoring data and water quality need improvements across Europe.
Aquatic ecosystems are at risk of being impaired by various organic chemicals, however comprehensive large-scale evaluations of waterbodies’ status and trends are rare. Here, surface water monitoring data, gathered as part of the EU Water Framework Directive and comprising the occurrence of 352 organic contaminants (>8.3 mil. measurements; 2001–2015; 8213 sites) in 31 European countries, was used to evaluate past and current environmental risks for three aquatic species groups: fish, invertebrates, plants. Monitoring quality indices were defined per country and found to improve over time. Relationships became apparent between countries’ monitoring quality index and their success in detecting contaminants. Across the EU, contaminants were more frequently found in recent years. Overall, 35.7% (n = 17,484) of sites exceeded at least one acute regulatory threshold level (RTL) each year, and average risks significantly increased over time for fish (τ = 0.498, p = 0.01) and aquatic invertebrates (τ = 0.429, p = 0.03). This indicates an increased chemical pressure to Europe’s waterbodies and overall large-scale threshold exceedances. Pesticides were identified as the main risk drivers (>85% of RTL exceedances) with aquatic invertebrates being most acutely at risk in Europe. Agricultural land-use was clearly identified as the primary spatial driver of the observed aquatic risks throughout European surface waters. Issues in monitoring data heterogeneity were highlighted and also followed by subsequent improvement recommendations, strengthening future environmental quality assessments. Overall, aquatic ecosystem integrity remains acutely at risk across Europe, signaling the demand for continued improvements.
Summary
Several observational studies have assessed the association between psoriasis, psoriatic arthritis (PsA) and type 2 diabetes mellitus, with inconclusive results. We set out to investigate the ...association between psoriasis, PsA and type 2 diabetes mellitus. Observational studies assessing the relationship between psoriasis or PsA and type 2 diabetes mellitus up to December 2012 were identified by electronic and hand searches in Medline, Embase, PubMed, the Cochrane Database of Systematic Reviews and Google Scholar. For each study we collected the first author's last name, publication year, country of origin, study design, characteristics of participants (sample size, age and sex), the variables incorporated into the multivariable analyses, and the odds ratios (ORs) of psoriasis associated with diabetes along with the corresponding 95% confidence intervals (CIs). From the data provided in each article, the crude OR was also calculated. Forty‐four observational studies (in 37 articles) were identified for the final analysis. The pooled OR from random‐effects analysis was determined to be 1·76 (95% CI 1·59–1·96). The highest risk was for patients suffering from PsA (OR 2·18, 95% CI 1·36–3·50). We also observed a dose effect in the risk of suffering from type 2 diabetes mellitus, as patients considered as having severe psoriasis had higher risk (OR 2·10, 95% CI 1·73–2·55) than the pooled OR. We perform meta‐regression and sensitivity analyses to explore sources of heterogeneity among the studies and to determine how they would influence the estimates, and found no significant influence in the results of the meta‐analyses. The findings support the association between psoriasis, PsA and type 2 diabetes mellitus. Some caution must be taken in the interpretation of these results because there may be heterogeneity between studies.
What's already known about this topic?
Several observational studies have assessed the association between psoriasis, psoriatic arthritis and type 2 diabetes mellitus, with inconclusive results.
What does this study add?
A systematic review and meta‐analysis including all observational studies up to December 2012.
Investigation of the influence of psoriatic arthritis and the severity of the disease on the risk of diabetes.
Aims.
We study the effect of disequilibrium processes (photochemistry and vertical transport) on mixing ratio profiles of neutral species and on the simulated spectra of a hot Jupiter exoplanet that ...orbits stars of various spectral types. We additionally address the impact of stellar activity that should be present, to various degrees, in all stars with convective envelopes.
Methods.
We used the VULCAN chemical kinetic code to compute number densities of species in irradiated planetary atmospheres. The temperature-pressure profile of the atmosphere was computed with the HELIOS code. We also utilized the
τ
-REx forward model to predict the spectra of planets in primary and secondary eclipses. In order to account for the stellar activity, we made use of the observed solar extreme ultraviolet (XUV) spectrum taken from Virtual Planetary Laboratory as a proxy for an active sun-like star.
Results.
We find large changes in the mixing ratios of most chemical species in planets orbiting A-type stars, which radiate strong XUV flux thereby inducing a very effective photodissociation. For some species, these changes can propagate very deep into the planetary atmosphere to pressures of around 1 bar. To observe disequilibrium chemistry we favor hot Jupiters with temperatures
T
eq
= 1000 K and ultra-hot Jupiters, with
T
eq
≈ 3000 K,which also have temperature inversion in their atmospheres. On the other hand, disequilibrium calculations predict no noticeable changes in spectra of planets with intermediate temperatures. We also show that stellar activity similar to that of the modern Sun drives important changes in mixing ratio profiles of atmospheric species. However, these changes take place at very high atmospheric altitudes and thus do not affect predicted spectra. Finally, we estimate that the effect of disequilibrium chemistry in planets orbiting nearby bright stars could be robustly detected and studied with future missions with spectroscopic capabilities in infrared such as
James Webb
Space Telescope and ARIEL.
Host trees are immediate environments for multi‐host mistletoes, so parasitizing different hosts implies exposure to varying environmental conditions between mistletoe generations. Therefore, to ...maximize reproductive fitness in heterogeneous environments (host species) mistletoes should adjust its reproductive responses in relation to circumstances.
Here, we ask how reproductive traits of Psittacanthus calyculatus mistletoes vary on two host tree species (Crataegus mexicana, Prunus serotina) at three different localities.
We followed individual mistletoes on each host species and at three localities through the flowering season to quantify traits related to reproductive effort and success, e.g. total number of buds, flowers and fruits produced. In buds about to open, we measured two anthers and quantified the number of pollen grains and their viability. Individual flowers were marked to obtain flower longevity data and were followed until fruit formation. At which time we measured and weighed the fruits and the seeds.
Mistletoes from one locality produced more buds, flowers and fruits, and the flowers lasted longer, had larger anthers and produced more pollen as compared to the other two localities. However, mistletoes on Prunus serotina produced fewer floral buds, but their fruits were heaviest, longest and widest and ripened fastest across localities. The probability of fruit formation, percentage of fruits formed, and pollen viability were similar among the mistletoes, regardless of host species or locality. We propose that the observed differences in reproductive effort and success associated with host species or locality are plastic or adaptive in this mistletoe in response to varying conditions.
Components of the reproductive effort in the mistletoe Psittacanthus calyculatus are affected when growing in different host species and locations but reproductive success is maintained, which implies that several climatic factors, host attributes or pollinator/seed disperser behaviors contribute to these differences.
Fetal growth plays a role in programming of adult cardiometabolic disorders, which in men, are associated with lowered testosterone levels. Fetal growth and fetal androgen exposure can also ...predetermine testosterone levels in men, although how is unknown, because the adult Leydig cells (ALCs) that produce testosterone do not differentiate until puberty. To explain this conundrum, we hypothesized that stem cells for ALCs must be present in the fetal testis and might be susceptible to programming by fetal androgen exposure during masculinization. To address this hypothesis, we used ALC ablation/regeneration to identify that, in rats, ALCs derive from stem/progenitor cells that express chicken ovalbumin upstream promoter transcription factor II. These stem cells are abundant in the fetal testis of humans and rodents, and lineage tracing in mice shows that they develop into ALCs. The stem cells also express androgen receptors (ARs). Reduction in fetal androgen action through AR KO in mice or dibutyl phthalate (DBP) -induced reduction in intratesticular testosterone in rats reduced ALC stem cell number by ∼40% at birth to adulthood and induced compensated ALC failure (low/normal testosterone and elevated luteinizing hormone). In DBP-exposed males, this failure was probably explained by reduced testicular steroidogenic acute regulatory protein expression, which is associated with increased histone methylation (H3K27me3) in the proximal promoter. Accordingly, ALCs and ALC stem cells immunoexpressed increased H3K27me3, a change that was also evident in ALC stem cells in fetal testes. These studies highlight how a key component of male reproductive development can fundamentally reprogram adult hormone production (through an epigenetic change), which might affect lifetime disease risk.
Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data ...reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently “tracks” oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
Agricultural insecticides occur in U.S. surface waters, yet our knowledge of their current and potential future large-scale risks for biodiversity is restricted. Here, we conducted a meta-analysis of ...measured insecticide concentrations (MICs; n = 5817; 1962–2017) in U.S. surface waters and sediments reported in 259 peer-reviewed scientific studies for 32 important insecticide compounds and their degradation products (n = 6). To assess overall and substance-specific ecological risks and future implications, MICs were compared with official U.S. Environmental Protection Agency regulatory threshold levels (RTLs) and insecticide use trends. Approximately half of the MICs, i.e., 49.4% (at 69.7% of the 644 sites covered), exceeded their RTLs, indicating substantial risks to the integrity of U.S. aquatic ecosystems and potential shortcomings of regulatory risk assessment procedures. Overall, pyrethroids had the highest exceedance rate (80.7%; n = 1808), followed by organophosphates and carbamates (42.2%, n = 2618), and organochlorines (33.3%, n = 468). Pronounced increasing use trends were found for neonicotinoids, which exceeded their chronic RTLs, i.e., those of high relevance due to neonicotinoids̀ persistence in surface waters, for 56.8% of MICs (22.2% for acute RTLs). A regression analysis of insecticide use trends, although to be interpreted with care, indicated a future increase in applied amounts of several high risk insecticides such as pyrethroids and neonicotinoids, suggesting elevated prospective risks for U.S. surface waters, biodiversity, and endangered species.
In this paper and its companion (Higuera et al., 2014--this issue), the latest advancements regarding Volume-averaged Reynolds-averaged Navier–Stokes (VARANS) are developed in OpenFOAM® and applied. ...A new solver, called IHFOAM, is programmed to overcome the limitations and errors in the original OpenFOAM® code, having a rigorous implementation of the equations. Turbulence modelling is also addressed for k-ϵ and k-ω SST models within the porous media. The numerical model is validated for a wide range of cases including a dam break and wave interaction with porous structures both in two and three dimensions. In the second part of this paper the model is applied to simulate wave interaction with a real structure, using an innovative hybrid (2D–3D) methodology.
•The Volume-Averaged RANS equations are developed in OpenFOAM.•IHFOAM overcomes the limitations and errors in the original OpenFOAM code.•Turbulence modeling is also addressed within the porous media.•The numerical model is calibrated and validated for 2D and 3D cases.
A complete ban on pesticide use in sensitive areas, such as nature conservation areas (NCA), is currently being debated in the EU as part of the Sustainable Use Regulation. NCA are strictly protected ...landscapes in Germany with minimal agricultural activity (<4.5 %) that serve as vital ecological refuges. However, it is largely unknown whether surface waters in German NCA are contaminated by pesticides. The current study uses extensive monitoring data (n = 3,822,553 measurements, 1998–2020, 208 pesticides) from the federal state of Saxony (18,416 km2), Germany, to characterize pesticide occurrence, contamination levels and risks (defined as exceedance of regulatory threshold levels) for surface waters in NCA (n = 68,277 measurements, mean size = 2.5 km2) in comparison to unprotected areas (n = 3,754,276). Pesticide detection frequencies show strong correlation between NCA and unprotected areas (UPA, R2= 0.70–0.92), but concentrations to be ∼40 % lower in protected areas. Ecological risk distributions for three major species groups are similar between NCA and UPA (fish = 79.8 % overlap in density distribution, invertebrates = 78.6 %, plants = 81.9 %). Threshold exceedances differ greatly among groups (fish = 0.9 %, aquatic invertebrates = 14.7 %, plants = 20.4 %). Based on principal component analysis, ecological risks for aquatic plants and aquatic invertebrates are strongly correlated with upstream agricultural land use (80.5–82.4 %) and are negatively correlated with upstream (semi)-natural land cover (90.1–97.3 %). Fluvial transport appears to be the most important pathway for contaminants into NCA surface waters, likely due to small conservation area size. Overall, surface waters in NCA are exposed to numerous organic contaminants causing ecological risks, highlighting the need to improve protection of these valuable water resources.
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•Large-scale monitoring data of 208 pesticides in protected surface waters•Pesticides are regularly detected in nature conservation areas.•Multiple pesticides or metabolites show high detection frequencies.•Noteworthy environmental risks in protected areas from pesticide exposure•Unprotected agricultural areas serve as contaminant sources via fluvial inflows.
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