Strong Negative Effect Research Articles

Promoter role of putrescine for molecular and biochemical processes under drought stress in barley

Drought, which adversely affects plant growth and continuity of life and reduces product yield and quality, is one of the most common abiotic stresses at the globally. One of the polyamines that regulates plant development and reacts to abiotic stressors, including drought stress, is Putrescine (Put). This study compared the physiological and molecular effects of applying exogenous Put (10 µM) to barley (Hordeum vulgare cv. Burakbey) under drought stress (− 6.30 mPa PEG 6000). The 21-day drought stress imposed on the barley plant had a strong negative effect on plant metabolism in all experimental groups. Exogenous Put treatment under drought stress had a reformative effect on the cell cycle (transitions from G0-G1 to S and from S to G2-M), total protein content (almost 100%), endogenous polyamine content, malondialdehyde (MDA) (70%), and ascorbate peroxidase (APX) (62%) levels compared to the drought stress plants. Superoxide dismutase (SOD) (12%) and catalase (CAT) (32%) enzyme levels in the same group increased further after exogenous Put application, forming a response to drought stress. Consequently, it was discovered that the administration of exogenous Put in barley raises endogenous polyamine levels and then improves drought tolerance due to increased antioxidant capability, cell division stimulation, and total protein content.

Exploring modes of microbial interactions with implications for methane cycling.

Methanotrophs are the sole biological sink of methane. Volatile organic compounds (VOCs) produced by heterotrophic bacteria have been demonstrated to be a potential modulating factor of methane consumption. Here, we identify and disentangle the impact of the volatolome of heterotrophic bacteria on the methanotroph activity and proteome, using Methylomonas as model organism. Our study unambiguously shows how methanotrophy can be influenced by other organisms without direct physical contact. This influence is mediated by VOCs (e.g. dimethyl-polysulphides) or/and CO2 emitted during respiration, which can inhibit growth and methane uptake of the methanotroph, while other VOCs had a stimulating effect on methanotroph activity. Depending on whether the methanotroph was exposed to the volatolome of the heterotroph or to CO2, proteomics revealed differential protein expression patterns with the soluble methane monooxygenase being the most affected enzyme. The interaction between methanotrophs and heterotrophs can have strong positive or negative effects on methane consumption, depending on the species interacting with the methanotroph. We identified potential VOCs involved in the inhibition while positive effects may be triggered by CO2 released by heterotrophic respiration. Our experimental proof of methanotroph-heterotroph interactions clearly calls for detailed research into strategies on how to mitigate methane emissions.

Rehabilitation outcomes of bird-building collision victims in the Northeastern United States.

Building collisions are a leading threat to wild birds; however, only those that are found dead or fatally wounded are included in current mortality estimates, with injured or stunned birds largely assumed to survive long-term. Avian building collision victims are often brought to wildlife rehabilitators for care, with the hopes they can be released and resume their natural lives. We examined the wildlife rehabilitation records of over 3,100 building collisions with 152 different avian species collected across multiple seasons to identify patterns of survival and release among patients. The number of admissions varied by season; fall migration had the highest number of cases and winter had the least number of cases, and summer having the lowest release proportion and winter having the highest. The most common reported injury was head trauma and concussion. Our logistic and Poisson models found that mass had a strong positive effect on release probability, and the season of summer had a strong negative effect on release probability. Mass and winter had a strong positive effect on treatment time, and age and the seasons of fall and winter had a strong negative effect on treatment time in these models. Ultimately, about 60% of patients died in care, either by succumbing to their injuries or by euthanasia. Patients that were released remained in care for longer than patients that died. This study reports different data than carcass studies and views bird-building collisions from the perspective of surviving victims to explore longer-term effects of these collisions on mortality. Increased communication and collaboration between wildlife rehabilitators and conservation researchers is recommended to better understand building collisions and how to respond to this leading threat to wild birds. These findings, along with our estimate of delayed mortality, suggest that overall collision mortality estimates based on carcass collection far exceed one billion birds in the U.S. each year.

Scale dependence and mechanisms of grazing‐induced biodiversity changes depend on herbivore type in semiarid grasslands

Abstract Grasslands support a variety of herbivores that profoundly impact biodiversity and ecosystem functioning at local and regional scales. Understanding how different herbivores influence plant diversity across multiple scales is crucial for effective biodiversity conservation. However, most studies have focussed on the effects of grazing intensity on plant diversity, neglecting the impacts and associated mechanisms of different herbivores across scales. Based on a 7‐year grazing experiment with 16 plots in Inner Mongolia's typical steppe, we compared the scale‐dependent effects of different herbivores (cattle, sheep and goats) on plant diversity at moderate grazing intensity. We used the species–area relationship (SAR) and linear mixed models to analyse the changes in species richness across multiple scales (1, 16, 32, 64, 128, 256, 512 and 1024 m2). To understand SAR slope changes, we examined four potential mechanisms: overall species richness, total number of individuals, species abundance distribution and species aggregation. We found that grazing had scale effects on plant diversity, as indicated by a significant decrease in the SAR slope. This decrease in slope suggests that the negative impacts of grazing were more pronounced at larger scales. Additionally, the scale effects of different herbivores on plant diversity varied. Cattle had stronger positive impacts on diversity than sheep and goats at both small (1 m2) and large (1024 m2) scales. Conversely, sheep and goats had stronger negative effects on diversity than did the control at the large scale (1024 m2). The decrease in the SAR slope was mainly caused by changes in overall species richness and species abundance distribution. This was primarily because cattle had a stronger impact on dominant species, whereas sheep and goats had a stronger impact on rare species. Synthesis: Our results demonstrate that even at the same intensity, the grazing effects on species diversity vary with the study scale, herbivore type and their interaction. This finding has important implications for the conservation of grassland biodiversity given that grazing typically occurs at larger scales than in studies with quadrats and involves various herbivores with distinct effects on plant diversity.

The day after mowing: Time and type of mowing influence grassland arthropods.

Recent losses in the abundance and diversity of arthropods have been documented in many regions and ecosystems. In grasslands, such insect declines are largely attributed to land use, including modern machinery and mowing regimes. However, the effects of different mowing techniques on arthropods remain poorly understood. Using 11 years of data from 111 agricultural grassland plots across Germany, we analyzed the influence of various grassland management variables on the abundance and abundance-accounted species richness of four arthropod orders: Araneae, Coleoptera, Hemiptera, and Orthoptera. The analysis focused on detailed mowing information, for example, days after mowing and mower type, and compared their effect with other aspects of grassland management, that is, rolling, leveling, fertilization, and grazing. We found strong negative effects of mowing on all four arthropod orders, with arthropod abundance being lowest directly after mowing and steadily increasing to three to seven times the abundance after 100 days post-mowing. Likewise, Hemiptera and Coleoptera species richness was 30% higher 100 days after mowing. Mower width showed a positive effect on Orthoptera abundance, but not on the other arthropods. Arthropod abundance and Coleoptera species richness were lowest when a mulcher was used compared to rotary or bar mowers. In addition to mowing, intensive grazing negatively affected Orthoptera abundance but not the other orders. Mowing represents a highly disturbing and iterative stressor with negative effects on arthropod abundance and diversity, likely contributed by mowing-induced mortality and habitat alteration. While modifications of mowing techniques such as mower type or mowing height and width may help to reduce the negative impact of mowing on arthropods, our results show that mowing itself has the most substantial negative effect. Based on our results, we suggest that reduced mowing frequency, omission of mowing in parts of the grassland (refuges), or extensive grazing instead of mowing have the greatest potential to promote arthropod populations.

Pitch-Tracking Metrics as a Predictor of Future Shoulder and Elbow Injuries in Major League Baseball Pitchers: A Machine-Learning and Game-Theory Based Analysis.

Understanding interactions between multiple risk factors for shoulder and elbow injuries in Major League Baseball (MLB) pitchers is important to identify potential avenues by which risk can be reduced while minimizing impact on player performance. To apply a novel game theory-based approach to develop a machine-learning model predictive of next-season shoulder and elbow injuries in MLB pitchers and use this model to understand interdependencies and interaction effects between the most important risk factors. Case-control study; Level of evidence, 3. Pitcher demographics, workload measures, pitch-tracking metrics, and injury data between 2017 and 2022 were used to construct a database of MLB pitcher-years, where each item in the database corresponded to a pitcher's information and metrics for that year. An extreme gradient boosting machine-learning model was trained to predict next-season shoulder and elbow injuries utilizing Shapley additive explanation values to quantify feature importance as well as interdependencies and interaction effects between predictive variables. A total of 3808 pitcher-years were included in this analysis; 606 (15.9%) of these involved a shoulder or elbow injury resulting in placement on the MLB injured list. Of the >65 candidate features (including workload, demographic, and pitch-tracking metrics), the most important contributors to predicting shoulder/elbow injury were increased: pitch velocity (all pitch types), utilization of sliders (SLs), fastball (FB) spin rate, FB horizontal movement, and player age. The strongest game theory interaction effects were that higher FB velocity did not alter a younger pitcher's predicted risk of shoulder/elbow injury versus older pitchers, risk of shoulder/elbow injury increased with the number of high-velocity pitches thrown (regardless of pitch type and in an additive fashion), and FB velocity <95 mph (<152.9 kph) demonstrated strong negative interaction effects with higher SL percentage, suggesting that the overall predicted risk of injury for pitchers throwing a high number of SLs could be attenuated by lower FB velocity. Pitch-tracking metrics were substantially more predictive of future injury than player demographics and workload metrics. There were many significant game theory interdependencies of injury risk. Notably, the increased risk of injury that was conferred by throwing with a high velocity was even further magnified if the pitchers were also older, threw a high percentage of SLs, and/or threw a greater number of pitches.

The gut-facial aging axis: A two-sample Mendelian randomization and mediation analysis of gut microbiota, gut microbiota metabolic pathways, and blood metabolites.

Facial aging (FA) is a complex process influenced by both genetic and environmental factors. Gut microbiota (GM), gut microbiota metabolic pathways (GMMPs), and blood metabolites (BMs) have been implicated in the regulation of FA, but the causal and mediating effects of these factors remain unclear. We used summary-level data from genome-wide association studies (GWAS) of 16S rRNA gene sequencing data for GM (n=18 340), GWAS of GMMPs (n=7738), BMs (n=24 925), and GWAS of FA (n=423 999). We applied Mendelian randomization (MR) methods to estimate the causal effects of GM, GMMPs, and BMs on FA. We performed mediation analysis to quantify the proportion of the effects mediated by blood metabolites. We identified nine genus, two phylum, two families of GM, nine GM metabolic pathways, and 73 BMs that showed potential causal effects on FA. After Bonferroni correction, three BMs remained causally associated with FA, including average number of methylene groups per double bond (β, -0.023; 95% CI, -0.032∼-0.014; p=3.120×10-7) and average number of methylene groups in a fatty acid chain (β, -0.031; 95% CI, -0.045∼-0.016; p=2.062×10-5), which had strong negative causal effects on FA, and ratio of bisallylic groups to total fatty acids (β, 0.023; 95% CI, 0.017∼-0.029; p=8.441×10-15), which had a strong positive causal effect on FA. Mediation analysis revealed that histidine, average number of methylene groups in a fatty acid chain, and triglycerides in chylomicrons and largest VLDL particles mediated the effects of anaerofilum and/ or superpathway of Laspartate and Lasparagine biosynthesis on FA. Our study provides novel insights into the causal and mediating effects of GM, GMMPs, and BMs on FA. These findings may have implications for the development of new strategies for preventing or delaying FA.

Impact of carbon market prices on oil market fear across quantiles

ABSTRACT This paper uses quantile regression to investigate how carbon market prices affect oil market fear. Our results show a significant and strong negative effect of changes in carbon market prices on changes in oil market fear at high quantiles. Notably, this negative effect is driven by the decrease rather than the increase in carbon market prices. We also observe that the COVID-19 pandemic enhances the negative impact of the decreased carbon market prices at high quantiles.

Transcriptomic balance and optimal growth are determined by cell size

Cell size and growth are intimately related across the evolutionary scale, but whether cell size is important to attain maximal growth or fitness is still an open question. We show that growth rate is a non-monotonic function of cell volume, with maximal values around the critical size of wild-type yeast cells. The transcriptome of yeast and mouse cells undergoes a relative inversion in response to cell size, which we associate theoretically and experimentally with the necessary genome-wide diversity in RNA polymerase II affinity for promoters. Although highly expressed genes impose strong negative effects on fitness when the DNA/mass ratio is reduced, transcriptomic alterations mimicking the relative inversion by cell size strongly restrain cell growth. In all, our data indicate that cells set the critical size to obtain a properly balanced transcriptome and, as a result, maximize growth and fitness during proliferation.

Warming and rainfall reduction alter soil microbial diversity and co-occurrence networks and enhance pathogenic fungi in dryland soils

In this 9-year manipulative field experiment, we examined the impacts of experimental warming (2 °C, W), rainfall reduction (30 % decrease in annual rainfall, RR), and their combination (W + RR) on soil microbial communities and native vegetation in a semi-arid shrubland in south-eastern Spain. Warming had strong negative effects on plant performance across five coexisting native shrub species, consistently reducing their aboveground biomass growth and long-term survival. The impacts of rainfall reduction on plant growth and survival were species-specific and more variable. Warming strongly altered the soil microbial community alpha-diversity and changed the co-occurrence network structure. The relative abundance of symbiotic arbuscular mycorrhizal fungi (AMF) increased under W and W + RR, which could help buffer the direct negative impacts of climate change on their host plants nutrition and enhance their resistance to heat and drought stress. Indicator microbial taxa analyses evidenced that the marked sequence abundance of many plant pathogenic fungi, such as Phaeoacremonium, Cyberlindnera, Acremonium, Occultifur, Neodevriesia and Stagonosporopsis, increased significantly in the W and W + RR treatments. Moreover, the relative abundance of fungal animal pathogens and mycoparasites in soil also increased significantly under climate warming. Our findings indicate that warmer and drier conditions sustained over several years can alter the soil microbial community structure, composition, and network topology. The projected warmer and drier climate favours pathogenic fungi, which could offset the benefits of increased AMF abundance under warming and further aggravate the severe detrimental impacts of increased abiotic stress on native vegetation performance and ecosystem services in drylands.

Spillover Effects of Urban Expansion on Land Green Use Efficiency: An Empirical Study Based on Multi-Source Remote Sensing Data in China

Land is an important carrier of resource elements, and improving land green use efficiency (LGUE) is the key to achieving “smart growth” in cities. This study takes 269 cities in China from 2008 to 2020 as the research object and integrates multisource remote sensing data, GIS spatial analysis, and spatial econometric models to explore the evolutionary characteristics of LGUE and the spatiotemporal effects of urban expansion on LGUE. The results show that (1) urban LGUE increases over time and has certain gradient distribution and spatial dependence characteristics; (2) urban expansion has a significant inverted U-shaped relationship with LGUE, indicating that maintaining reasonable urban expansion is the key to improving LGUE, but excessive urban expansion has a strong negative spatial effect on LGUE. In terms of spillover effect, for every 1% increase in the square term of urban expansion, the LGUE of the local city decreases by 0.0673%, but the neighboring city increases by 0.2283%; and (3) urban expansion has significant spatiotemporal heterogeneous effects on LGUE, and spatial development boundaries must be reasonably determined to achieve “smart growth”. Currently, some cities in China are expanding rapidly, and we hope to provide key support for promoting the “smart growth” of cities and improving LGUE.

Enhanced Removal of Cr (VI) by PEI/nFe3O4 Ultrafiltration Membranes Using Peristaltic Pump-Driven Dynamic Adsorption

In this study, Fe3O4 nanoparticles (nFe3O4) were loaded onto polyvinylidene fluoride ultrafiltration membranes and capped with polyethyleneimine in order to form PEI/nFe3O4 ultrafiltration membranes. We used a peristaltic pump as a driver for dynamic adsorption, and the PEI/nFe3O4 ultrafiltration membrane had a good ability to remove hexavalent chromium (Cr(VI)) from wastewater. The full permeate volume of the PEI/nFe3O4 ultrafiltration membrane was maximized at pH 3. Meanwhile, the removal of Cr(VI) from the wastewater reached 98% and reduced to trivalent chromium (Cr(III)). When the initial concentration of Cr(VI) increased, the active sites on the membrane would be filled and the removal efficiency of Cr(VI) would decrease. Meanwhile, the coexisting ions affect the removal efficiency of Cr(VI), and PO43- has a strong negative effect on the removal efficiency. PEI/nFe3O4 ultrafiltration membrane is an effective combination of multifunctional nanomagnetic materials and membrane materials, which can effectively remove hexavalent chromium from wastewater. The study provides a basis for future applications in the environmental remediation of low-concentration chromium-containing wastewater.

Learning of Intimate Area Examination Amongst Pakistani Medical Students: Knowledge, Attitudes, and Practices Study

Background: Intimate area examination (IAE) is an integral part of clinical examination skills and must be mastered by medical students before they start their careers. This study explores the experiences of Pakistani medical students regarding learning of IAE, the associated barriers and their effects on students’ learning. Methods: This cross-sectional study, based on a self-designed questionnaire, was conducted at two Pakistani medical colleges, which included final year students and postgraduate trainees. Results: During their undergraduate training, 74.9% of the respondents had not conducted a female pelvic examination, 51.9% had not examined a female groin, 79.7% had not examined a female rectum, and 72.7% had not examined a male rectum. From the 65 postgraduate doctors, 48.4% reported that they were not prepared to perform an IAE at the start of their clinical career. Regarding barriers to IAE learning, more than half of the respondents felt that the opposite gender of the patient (64.7%) and patient’s refusal (63.1%) had a strong negative effect on IAE learning. A high percentage of respondents reports that they were not taught IAE during their undergraduate years. Among the currently used pedagogical techniques, 71.1% of the respondents opted for real patient-based learning, followed by clinical simulations (21.9%), and videos (7.0%). No one thought examination should be taught theoretically. A significant difference between male and female experience in IAE learning was also observed. Conclusion: Learning of IAE remains unsatisfactory and poses a major challenge for the Pakistani Medical Students in the institutes included in this study.

Substrate scent-induced disproportionate seed dispersal by rodents.

Conspecific adults impose strong negative density-dependent effects on seed survival nearby parent trees, however, the underlying mechanisms are diversified and remain unclear. In this study, we presented consistent evidence that parent-scented forest floor masked seed odor, reduced cache recovery rate by scatter-hoarding animals, and then increased seed dispersal far away from mother trees. Our results showed that seed odors of Korean pine Pinus koraiensis match well with the volatile profile of their forest floor. Moreover, scatter-hoarding animals selectively transported P. koraiensis seeds toward the areas where seed odor was more contrasting against the background substrate, possibly due to the fact that accumulation of conspecific volatile compounds in caches hindered seed detection by scatter-hoarding animals. Our study provides insight into the role of leaf litter in directing seed dispersal process, representing a novel mechanism by which P. koraiensis increases selection for seed dispersal far away from the parent tree.

Unpacking Legitimacy Perceptions of Investment Dispute Settlement: Effects of Outcome and Procedure

Abstract How do citizens perceive different avenues for resolving investor–state disputes in case of an unfavorable decision? In this article, I argue that the interplay between procedure- and outcome-related considerations influences citizens’ legitimacy beliefs toward investor-state dispute settlement (ISDS) systems. First, an unfavorable ISDS ruling should decrease public legitimacy beliefs in the country that got sued. Second, the type of dispute settlement mechanism should influence legitimacy beliefs, leading to different assessments of the legal proceedings. I fielded a survey experiment in France, Germany, and the United States to test these theoretical expectations. The findings confirm that an unfavorable ISDS ruling has a strong negative effect on public perceptions of the legal proceeding, but further show that appropriate design choices can boost public legitimacy beliefs. These results have important implications for the debate about ISDS reform and the scholarship on legitimacy in global governance. The impact of unfavorable decisions on public legitimacy beliefs has been widely overlooked.

Ramadhan effect towards Nifty Shariah indices in India

PurposeThis paper aims to analyse the weekday effect on the Nifty Shariah indices as per the Islamic calendar. The study is intended to know about the return and volatility of these indices during Ramadhan and non-Ramadhan days.Design/methodology/approachThe study focuses on analysing the Nifty Shariah indices and Sensex daily returns collected from NSE India and BSE India, respectively, during the period of 1 August 2016 to 31 July 2022. Descriptive statistics are used to analyse the data, while the Ordinary Least Square method is used to determine the impact of weekdays on the Nifty Shariah indices. Additionally, the study applies the GARCH statistical model to examine the influence of Ramadhan on the returns and volatility of the Nifty Shariah indices.FindingsAll of the Nifty Shariah indices produced positive returns during the overall sample period. According to the study, Tuesday index returns outperform other weekdays. The GARCH model indicated that the coefficient values for the Nifty 50 Shariah and Nifty 500 Shariah indices were negative. Ramadhan has a strong negative effect on volatility, according to this study.Originality/valueThe outcomes of the research are beneficial for investors aiming to exploit daily or weekly price fluctuations, rather than pursuing extended investment periods. Furthermore, fund managers can employ these findings to shape trading strategies, and academics can examine the performance of Shariah indices in the Indian context. This enables devout investors to make significant financial choices, thus advancing ethical values in society and upholding standards of both public and private morality.

Forest type modulates mammalian responses to megafires

Although considered an evolutionary force responsible for shaping ecosystems and biodiversity, fires’ natural cycle is being altered by human activities, increasing the odds of destructive megafire events. Here, we show that forest type modulates the responses of terrestrial mammals, from species to assemblage level, to a catastrophic megafire in the Brazilian Pantanal. We unraveled that mammalian richness was higher 1 year after fire passage compared to a pre-fire condition, which can be attributed to habitat modification caused by wildfires, attracting herbivores and open-area tolerant species. We observed changes in assemblage composition between burned/unburned sites, but no difference in mammalian richness or relative abundance. However, by partitioning the effects of burned area proportion per forest type (monospecific vs. polyspecific), we detected differential responses of mammals at several levels of organization, with pronounced declines in species richness and relative abundance in monospecific forests. Eighty-six percent of the species presented moderate to strong negative effects on their relative abundance, with an overall strong negative effect for the entire assemblage. Wildfires are predicted to be more frequent with climate and land use change, and if events analogous to Pantanal-2020 become recurrent, they might trigger regional beta diversity change, benefitting open-area tolerant species.

Complex anti-relapse therapy of various variants of the course of the vulvar lichen sclerosus: A randomized prospective study

Aim. To develop and evaluate the effectiveness of complex therapy of vulvar lichen sclerosus (VLS), considering the clinical and immunological variant (CIV) of the disease. Materials and methods. A randomized prospective study included 292 patients 20-70 years old with different CIVs of the VLS course: atrophic (n=101), sclerosing (n=154), scleroatrophic (n=37), as well as 35 females with VLS in the comparison group of the same age category. Based on the clinical, immunological, and morphological features of the VLS course, a complex anti-relapse therapy was developed, the effectiveness of which was evaluated after a year of follow-up in comparison with the standard of care (SoC) of patients (from the comparison group) based on the number of disease relapses and the results of the Vulvar Quality of Life Index Questionnaire (VQLI) survey of women with vulvar diseases. Results. In patients with the sclerosing variant of VLS, short courses of topical glucocorticoids during exacerbations are justified; in patients with the scleroatrophic variant – topical calcineurin inhibitors, in the atrophic variant – a protein-peptide complex from porcine blood leukocytes (vaginal suppositories and cream-balsam with lanolin) containing interleukin-1, 6, tumor necrosis factor α, transforming growth factor, macrophage migration inhibitory factor. Patients with any variant of VLS are instructed to follow household and hygienic recommendations, use emollients daily, take prophylactic doses of vitamins A, E, and D to correct its deficiency or insufficiency, as well as use local enzyme therapy, as indicated, aimed at preventing or treatment of cicatricial changes. Local estrogens were prescribed only to women with genitourinary menopausal syndrome in the peri- and postmenopausal period. The developed complex anti-relapse therapy of VLS showed greater clinical efficacy compared to SoC: 3.7-fold decrease in episodes of disease exacerbation, as well as a significant (p=0.001) 1.3-fold decrease in the negative effect of VLS on the QoL of patients in the main clinical group (15.4 points according to the VQLI assessment – a mild effect on QoL) compared to SoC with the average score of 27.6, which corresponded to a strong negative effect of the disease on QoL. Conclusion. The results of the study support the distinction of VLS CIVs and the need to consider their features when choosing an effective therapy for the disease. Properly selected complex, supportive therapy of VLS can significantly increase the QoL of patients, minimize the number of relapses, and prevent the development of complications, including, probably, the risk of malignant transformation.

Basking improves but winter warming worsens overwinter survival in the linden bug

The present study investigates the effects of rare winter basking behavior (observed in wild populations of the Linden bug, Pyrrhocoris apterus) and the effects of winter warming (predicted by climate models) on overwinter survival and physiology of P. apterus. The insects were exposed to scenarios simulating basking and winter warming in the laboratory. Part of the insects were exposed to real winters under semi-natural conditions in the field for comparison. The results show a clear positive effect of winter basking, implying that basking behavior is critical for overwinter survival in P. apterus. In contrast, winter warming was found to have a strong negative effect on overwinter survival, potentially representing a threat to central European populations of P. apterus. Physiological parameters (mass, water content, SCP, energy reserves) measured in this study cannot fully explain all the results. Further study is needed to better understand the mechanisms behind the positive effects of winter basking and the negative effects of winter warming on overwintering P. apterus.

Effects of persistent organic pollutants on telomere dynamics are sex and age-specific in a wild long-lived bird

Chemical pollution is a major man-made environmental threat to ecosystems and natural animal populations. Of concern are persistent organic pollutants (POPs), which can persist in the environment for many years. While bioaccumulating throughout the lives of wild animals, POPs can affect their health, reproduction, and survival. However, measuring long-term effects of POPs in wild populations is challenging, and therefore appropriate biomarkers are required in wildlife ecotoxicology. One potential target is telomere length, since telomere preservation has been associated to survival and longevity, and stressors as chemical pollution can disrupt its maintenance. Here, we investigated the effects of different classes of POPs on relative telomere length (RTL) and its rate of change (TROC) in wild long-lived Alpine swifts (Tachymarptis melba). As both RTL and TROC are often reported to differ between sexes and with chronological age, we tested for sex- and age-specific (pre-senescent vs. senescent, ≥ 9 age of years, individuals) effects of POPs. Our results showed that senescent females presented longer RTL and elongated telomeres over time compared to pre-senescent females and males. These sex- and age-related differences in RTL and TROC were influenced by POPs, but differently depending on whether they were organochlorine pesticides (OCPs) or industrial polychlorinated biphenyls (PCBs). OCPs (particularly drins) were negatively associated with RTL, with the strongest negative effects being found in senescent females. Conversely, PCBs led to slower rates of telomere shortening, especially in females. Our study indicates diametrically opposed effects of OCPs on RTL and PCBs on TROC, and these effects were more pronounced in females and senescent individuals. The mechanisms behind these effects (e.g., increased oxidative stress by OCPs; upregulation of telomerase activity by PCBs) remain unknown. Our results highlight the importance in wildlife ecotoxicology to account for sex- and age-related effects when investigating the health effects of pollutants on biomarkers such as telomeres.