Climatic changes: knowledge and adaptation behavior to heat-related illness among solid waste disposal workers.

BACKGROUND: Earth's climate changes are progressing at an alarming rate. One of the most severe effects of climate change is extreme heat. This study aimed to assess knowledge and adaptation behavior to heat-related illness (HRI) among solid waste disposal workers in the 10th of Ramadan City, Egypt, and to study the predictors for their knowledge and adaptation behavior. METHODS: An exploratory cross-sectional study was conducted on 220 solid waste disposal workers. A structured interview questionnaire was used to assess the studied workers' sociodemographic and occupational characteristics, heat exposure risk, and their knowledge, and adaptation behavior. RESULTS: The results showed that 40% and 30% of participants had adequate levels of total knowledge and adaptation behavior, respectively. There was a statistically significant relationship between workers' knowledge and both age and education. There was a statistically significant relationship between workers' adaptation behavior and age, duration of employment, working hours, and education. A binary logistic regression for significant predictors of knowledge and adaptation behavior showed that age and education were the most significant predictors. CONCLUSION: Solid waste disposal workers were at high risk of HRI due to their low levels of knowledge and adaptation behavior regarding HRI. Educational health programs that guide workers to follow healthy behaviors and prevent HRI are recommended.

Comparative phylogeography reveals the demographic patterns of neotropical ancient mountain species.

Mountains are renowned for their bountiful biodiversity. Explanations on the origin of such abundant life are usually regarded to their orogenic history. However, ancient mountain systems with geological stability also exhibit astounding levels of number of species and endemism, as illustrated by the Brazilian Quartzitic Mountains (BQM) in Eastern South America. Thus, cycles of climatic changes over the last couple million years are usually assumed to play an important role in the origin of mountainous biota. These climatic oscillations potentially isolated and reconnected adjacent populations, a phenomenon known as flickering connectivity, accelerating speciation events due to range fragmentation, dispersion, secondary contact, and hybridization. To evaluate the role of the climatic fluctuations on the diversification of the BQM biota, we estimated the ancient demography of distinct endemic species of animals and plants using hierarchical approximate Bayesian computation analysis and Ecological Niche Modelling. Additionally, we evaluated if climatic oscillations have driven a genetic spatial congruence in the genetic structure of codistributed species from the Espinhaço Range, one of the main BQM areas. Our results show that the majority of plant lineages underwent a synchronous expansion over the Last Glacial Maximum (LGM, c. 21 thousand years ago), although we could not obtain a clear demographic pattern for the animal lineages. We also obtained a signal of a congruent phylogeographic break between lineages endemic to the Espinhaço Range, suggesting how ancient climatic oscillations might have driven the evolutionary history of the Espinhaço's biota.

Coat color affects the resilience against heat stress impacts on testicular hemodynamics, reproductive hormones, and semen quality in Baladi goats.

Drastic climatic changes threaten animal productivity and prolificacy, whose adaptability is governed by its pheno- and genotypic traits. This study was aimed at investigating the effect of coat color on the adaptability of goat bucks under heat stress conditions from the perspectives of testicular blood flow (TBF) and biometry, reproductive hormones, and semen quality. Twenty bucks (Capra hircus) bearing different coat colors were selected from a large flock and divided into four equal groups (n = 5 each) as follows: black coat (BC; 100% black), brown coat (BrC; 100% dark brown), white coat (WC; 100% white), white-black coat (WBC; 50-60% white). Bucks were examined for TBF [Doppler ultrasonography and serum nitric oxide (NO)], testosterone (T) and luteinizing hormone (LH), seminal plasma oxidative biomarkers [catalase (CAT), total antioxidant capacity (TAC), and malondialdehyde (MDA)], and sperm traits percentages [progressive motility (PM), viability (SV), normal morphology (NM), and sperm concentration (SC) once a week for seven consecutive weeks (W1-W7) in the summer season (temperature humidity index = 88.4-92.2). Specifically, at W3-W7, darker bucks (BC and BrC) testicular volume, testicular colored area, T, NO, CAT, TAC, PM, SV, NM, and SC (W7 only) differed significantly (P < 0.05) by decrease than the lighter ones (WC and WBC). Both Doppler indices and serum MDA concentrations were elevated (P < 0.05) at W3-W7 in the BC and BrC bucks compared to WC and WBC groups. In conclusion, bucks with lighter coats were more resistant to the negative effects of HS on TBF, seminal oxidative biomarkers, and semen quality.

Comparative and predictive phylogeography in the South American diagonal of open formations: Unravelling the biological and environmental influences on multitaxon demography.

Phylogeography investigates historical drivers of the geographical distribution of intraspecific lineages. Particular attention has been given to ecological, climatic and geological processes in the diversification of the Neotropical biota. Several species sampled across the South American diagonal of open formations (DOF), comprising the Caatinga, Cerrado and Chaco biomes, experienced range shifts coincident with Quaternary climatic changes. However, comparative studies across different spatial, temporal and biological scales on DOF species are still meagre. Here, we combine phylogeographical model selection and machine learning predictive frameworks to investigate the influence of Pleistocene climatic changes on several plant and animal species from the DOF. We assembled mitochondrial/chloroplastic DNA sequences in public repositories and inferred the demographic responses of 44 species, comprising 70 intraspecific lineages of plants, lizards, frogs, spiders and insects. We then built a random forest model using biotic and abiotic information to identify the best predictors of demographic responses in the Pleistocene. Finally, we assessed the temporal synchrony of species demographic responses with hierarchical approximate Bayesian computation. Biotic variables related to population connectivity, gene flow and habitat preferences largely predicted how species responded to Pleistocene climatic changes, and demographic changes were synchronous primarily during the Middle Pleistocene. Although 22 (~31%) lineages underwent demographic expansion, presumably associated with the spread of aridity during the glacial Pleistocene periods, our findings suggest that nine lineages (~13%) exhibited the opposite response due to taxon-specific attributes.

Genome-wide supermatrix analyses of maples (Acer, Sapindaceae) reveal recurring inter-continental migration, mass extinction, and rapid lineage divergence.

Acer (Sapindaceae) is an exceptional study system for understanding the evolutionary history, divergence, and assembly of broad-leaved deciduous forests at higher latitudes. Maples stand out due to their high diversity, disjunct distribution pattern across the northern continents, and rich fossil record dating back to the Paleocene. Using a genome-wide supermatrix combining plastomes and nuclear sequences (~585 kb) for 110 Acer taxa, we built a robust time-calibrated hypothesis investigating the evolution of maples, inferring ancestral ranges, reconstructing diversification rates over time, and exploring the impact of mass-extinction on lineage accumulation. Contrary to fossil evidence, our results indicate Acer first originated in the (north)eastern Palearctic region, which acted as a source for recurring outward migration. Warm conditions favored rapid Eocene-onward divergence, but ranges and diversity declined extensively as a result of the Plio-Pleistocene glacial cycles. These signals in genome-wide sequence data corroborate paleobotanical evidence for other major woody north-temperate groups, highlighting the significant (disparate) impact of climatic changes on the evolution, composition, and distribution of the vegetation in the northern hemisphere.

Endophytic fungus diversity in soybean plants submitted to conditions of elevated atmospheric CO2 and temperature.

Global climatic changes can have drastic impacts on plant species, including severe consequences for the agricultural species productivity. Many of these species present important mutualisms with endophytic fungi that positively influence their performance. The present study evaluated whether the increases in CO2 and temperature predicted for the year 2100 may cause changes in foliar carbon (C) and nitrogen (N) concentrations in soybean (Glycine max) and, consequently, the interactions with its endophytic fungi. The effects of elevated CO2 and temperature were evaluated in four treatments in open-top chambers: (i) control, (ii) increased temperature, (iii) increased CO2, and (iv) increased CO2 and temperature. Increased atmospheric CO2 resulted in decreased foliar N concentration, while increased temperature increased it. A total of 16 taxa of endophytic fungi were identified based on sequencing internal transcribed spacer regions of rRNA subunits. Increased atmospheric CO2 and temperature were observed to potentially modify the endophytic mycobiota of soybean plants. The results suggest that the fungi species substitution is a consequence of changes in foliar N concentration and C/N ratio. Predicted climatic changes shall affect the relationships between plant and endophytes, which in turn, will affect the performance and resistance of soybean, one of the most important crops in the world.

A relic of the past: current genetic patterns of the palaeoendemic tree Nothofagus macrocarpa were shaped by climatic oscillations in central Chile.

BACKGROUND AND AIMS: The Mediterranean-type forest of central Chile is considered a 'biodiversity hotspot' and a relic of a wider ancient distribution produced by past climatic oscillations. Nothofagus macrocarpa, commonly known as 'roble de Santiago', is a threatened palaeoendemic of this forest, poorly represented in the protected area system. This tree has been repeatedly misidentified as the sister species N. obliqua, which has affected its recognition and protection. Only a few populations of N. macrocarpa remain within a matrix of intensive land use that has been affected by recent forest fires. We tested the hypothesis that current populations of N. macrocarpa are a relic state of a previously widespread range, with the aim of contributing to its identification, its biogeographical history and the design of conservation measures using genetic information. METHODS: We analysed remnant N. macrocarpa forests using nuclear (nDNA) and chloroplast DNA (cpDNA) sequences, conducted phylogenetic and phylogeographical analyses to reconstruct its biogeographical history, and assessed microsatellites [simple sequence repeats (SSRs)] to determine contemporary patters of diversity within and among all remnant populations. We also examined the degree of past, current and potential future isolation of N. macrocarpa populations using ecological niche models (ENMs). KEY RESULTS: The species N. macrocarpa was confirmed by nDNA sequences, as previously suggested by chromosomal analysis. Small isolated populations of N. macrocarpa exhibited moderate to high genetic diversity according to SSRs. cpDNA analysis revealed a marked past latitudinal geographical structure, whereas analysis of SSRs did not find such current structure. ENM analyses revealed local expansion-contraction of the N. macrocarpa range during warmer periods, particularly in the northern and central ranges where basal-most cpDNA haplotypes were detected, and recent expansion to the south of the distribution. CONCLUSIONS: Genetic patterns confirm that N. macrocarpa is a distinct species and suggest a marked latitudinal relic structure in at least two evolutionarily significant units, despite contemporary among-population gene flow. This information must be considered when choosing individuals (seeds and/or propagules) for restoration purposes, to avoid the admixture of divergent genetic stocks.

Measuring Recreation Benefit Loss under Climate Change with Revealed and Stated Behavior Data: The Case of Lac Saint-Pierre World Biosphere Reserve (Québec, Canada).

Based on a case study carried out on the Lac Saint-Pierre (LSP) World Biosphere Reserve (Québec, Canada), this paper estimates ecosystem service loss, more precisely the loss related to cultural and recreational activities of the LSP due to the fall of its water level under the pressure of climate change. We measure two dimensions of this loss. As a first step, the extrapolation of our representative survey reports $100 million annual loss in terms of recreation revenue due to the trip reduction to LSP, which is about 60% of current level. Subsequently, the travel-cost data and the contingent behavior data are combined in a revealed and stated behavior panel random-effect estimation, which reports an additional loss measured by consumer surplus that visitors can obtain from their trips up to $232 million, signifying 42% of reduction in their current value.

Population Genomics Reveals Speciation and Introgression between Brown Norway Rats and Their Sibling Species.

Murine rodents are excellent models for study of adaptive radiations and speciation. Brown Norway rats (Rattus norvegicus) are successful global colonizers and the contributions of their domesticated laboratory strains to biomedical research are well established. To identify nucleotide-based speciation timing of the rat and genomic information contributing to its colonization capabilities, we analyzed 51 whole-genome sequences of wild-derived Brown Norway rats and their sibling species, R. nitidus, and identified over 20 million genetic variants in the wild Brown Norway rats that were absent in the laboratory strains, which substantially expand the reservoir of rat genetic diversity. We showed that divergence of the rat and its siblings coincided with drastic climatic changes that occurred during the Middle Pleistocene. Further, we revealed that there was a geographically widespread influx of genes between Brown Norway rats and the sibling species following the divergence, resulting in numerous introgressed regions in the genomes of admixed Brown Norway rats. Intriguing, genes related to chemical communications among these introgressed regions appeared to contribute to the population-specific adaptations of the admixed Brown Norway rats. Our data reveals evolutionary history of the Brown Norway rat, and offers new insights into the role of climatic changes in speciation of animals and the effect of interspecies introgression on animal adaptation.

Legume genetic resources and transcriptome dynamics under abiotic stress conditions.

Grain legumes are an important source of nutrition and income for billions of consumers and farmers around the world. However, the low productivity of new legume varieties, due to the limited genetic diversity available for legume breeding programmes and poor policymaker support, combined with an increasingly unpredictable global climate is resulting in a large gap between current yields and the increasing demand for legumes as food. Hence, there is a need for novel approaches to develop new high-yielding legume cultivars that are able to cope with a range of environmental stressors. Next-generation technologies are providing the tools that could enable the more rapid and cost-effective genomic and transcriptomic studies for most major crops, allowing the identification of key functional and regulatory genes involved in abiotic stress resistance. In this review, we provide an overview of the recent achievements regarding abiotic stress resistance in a wide range of legume crops and highlight the transcriptomic and miRNA approaches that have been used. In addition, we critically evaluate the availability and importance of legume genetic resources with desirable abiotic stress resistance traits.

Ethiopian highlands as a cradle of the African fossorial root-rats (genus Tachyoryctes), the genetic evidence.

Root-rats of the genus Tachyoryctes (Spalacidae) are subterranean herbivores occupying open humid habitats in the highlands of Eastern Africa. There is strong disagreement about species diversity of the genus, because some authors accept two species, while others more than ten. Species with relatively high surface activity, the giant root-rat Tachyoryctes macrocephalus, which is by far largest member of the genus, and the more fossorial African root-rat Tachyoryctes splendens, which eventually has been divided up to 12-13 species, represent two major morphological forms within the genus. In our study, we carried out a multilocus analysis of root-rats' genetic diversity based on samples from 41 localities representing most of Tachyoryctes geographic distribution. Using two mitochondrial and three nuclear genes, we found six main genetic clades possibly representing separate species. These clades were organised into three basal groups whose branching is not well resolved, probably due to fast radiation in the late Pliocene and early Pleistocene. Climatic changes in that time, i.e. fast and repeated changes between extremely dry and humid conditions, which both limited root-rat dispersal, probably stimulated their initial genetic diversification. Contrary to expectation based on the largest root-rat diversity in Kenya (up to eight species by some authors), we found the highest diversity in the Ethiopian highlands, because all but one putative species occur there. All individuals outside of Ethiopia belong to a single recently diverged and expanded clade. This species should bear the name T. annectens (Thomas, 1891), and all other names of taxa described from outside of Ethiopia should be considered its junior synonyms. However, to solve taxonomic issues, future detailed morphological analyses should be conducted on all main clades together with genetic analysis of material from areas of their supposed contact. One of the most interesting findings of the study is the internal position of T. macrocephalus in T. splendens sensu lato. This demonstrates the intriguing phenomenon of accelerated morphological evolution of rodents occupying the Afroalpine zone in Ethiopia. Finally, we discuss how the distribution of Tachyoryctes is influenced by competition with another group of subterranean herbivores on the continent, the African mole-rats. We assume that both groups do not compete directly as previously expected, but specialisation to different subterranean niches is the main factor responsible for their spatial segregation.

With or without you: Effects of the concurrent range expansion of an herbivore and its natural enemy on native species interactions.

Global climatic changes may lead to the arrival of multiple range-expanding species from different trophic levels into new habitats, either simultaneously or in quick succession, potentially causing the introduction of manifold novel interactions into native food webs. Unraveling the complex biotic interactions between native and range-expanding species is critical to understand the impact of climate change on community ecology, but experimental evidence is lacking. In a series of laboratory experiments that simulated direct and indirect species interactions, we investigated the effects of the concurrent arrival of a range-expanding insect herbivore in Europe, Spodoptera littoralis, and its associated parasitoid Microplitis rufiventris, on the native herbivore Mamestra brassicae, and its associated parasitoid Microplitis mediator, when co-occurring on a native plant, Brassica rapa. Overall, direct interactions between the herbivores were beneficial for the exotic herbivore (higher pupal weight than the native herbivore), and negative for the native herbivore (higher mortality than the exotic herbivore). At the third trophic level, both parasitoids were unable to parasitize the herbivore they did not coexist with, but the presence of the exotic parasitoid still negatively affected the native herbivore (increased mortality) and the native parasitoid (decreased parasitism rate), through failed parasitism attempts and interference effects. Our results suggest different interaction scenarios depending on whether S. littoralis and its parasitoid arrive to the native tritrophic system separately or concurrently, as the negative effects associated with the presence of the parasitoid were dependent on the presence of the exotic herbivore. These findings illustrate the complexity and interconnectedness of multitrophic changes resulting from concurrent species arrival to new environments, and the need for integrating the ecological effects of such arrivals into the general theoretical framework of global invasion patterns driven by climatic change.

Historical demography and colonization pathways of the widespread intertidal seaweed Hormosira banksii (Phaeophyceae) in southeastern Australia.

The palaeoceanography of southern Australia has been characterized by fluctuating sea levels during glacial periods, changing temperature regimes and modified boundary currents. Previous studies on genetic structuring of species in southeastern Australia have focused mainly on the differentiation of eastern and western populations while the potential role of Bass Strait as a region of overlap for three biogeographic provinces (Peronia, Maugea, and Flindersia) has been largely ignored. This study aimed to explore the likely roles of historic and contemporary factors in determining divergence patterns in the habitat-forming intertidal seaweed Hormosira banksii in southeastern Australia with a special focus on postglacial dispersal into Bass Strait. We examined the genetic diversity of 475 Hormosira specimens collected from 19 sites around southern Australia using DNA sequence analysis of cytochrome oxidase 1. Three major haplotype groups were identified (western, centre and eastern) corresponding with the three existing biogeographical provinces in this region. Historic break points appeared to be retained and reinforced by modern day dispersal barriers. Phylogeographic grouping of Hormosira reflected a combination of historic and contemporary oceanography. As western and eastern group haplotypes were largely absent within Bass Strait, re-colonization after the last glacial maximum appeared to have originated from refuges within or near present day Bass Strait. Patterns of genetic structure for Hormosira are consistent with other marine species in this region and highlight the importance of biogeographical barriers in contributing to modern genetic structure.

[The comprehensive evaluation of the bioclimatic comfort at the territories of the Russian Far East with reference to winter-time recreational activities and primary wellness tourism].

BACKGROUND: in the framework of the current tendency toward the further development of the socio-economic sphere in the Russian Far East (RFE), the relevant investigations aimed at creating the comfortable conditions for recreational and touristic activities as well as for rehabilitative therapy of the local population acquire the increasingly greater importance. AIM: The objective of the present study was the comprehensive evaluation of the bioclimatic comfort at the territories of interest with special reference to winter-time recreational activities and primary wellness tourism. MATERIALS AND METHODS: This study was designed to evaluate the health resort, recreational, and therapeutic resources of the selected areas of the Russian Far East with special reference to the data provided by the climate monitoring stations during the periods from December to March of 1965-2014. The following methods were used for the purpose: the comparative analysis of climatic information and elementary methods of mathematical statistics. RESULTS: The evaluation of the study territory in terms of the bioclimatic comfort gave evidence that the southern regions of Primorye as well as Sakhalin island, and Kamchatka peninsula provide the most favorable conditions for the therapeutic and recreational activities, leisure and sports in the winter seasons. CONCLUSION: The analysis of the studied bioclimatic indices of comfort at different territories of the Russian Far East has demonstrated their great potential for the further development of recreation services, rehabilitation, sporting and touristic activities. The study has revealed the new opportunities for the enhancement of bioclimatic comfort of the region and for the improvement of the quality of life and employment of the local population.

Genetic consequences of Quaternary climatic oscillations in the Himalayas: Primula tibetica as a case study based on restriction site-associated DNA sequencing.

The effects of Quaternary climatic oscillations on the demography of organisms vary across regions and continents. In taxa distributed in Europe and North America, several paradigms regarding the distribution of refugia have been identified. By contrast, less is known about the processes that shaped the species' spatial genetic structure in areas such as the Himalayas, which is considered a biodiversity hotspot. Here, we investigated the phylogeographic structure and population dynamics of Primula tibetica by combining genomic phylogeography and species distribution models (SDMs). Genomic data were obtained for 293 samples of P. tibetica using restriction site-associated DNA sequencing (RADseq). Ensemble SDMs were carried out to predict potential present and past distribution ranges. Four distinct lineages were identified. Approximate Bayesian computation analyses showed that each of them have experienced both expansions and bottlenecks since their divergence, which occurred during or across the Quaternary glacial cycles. The two lineages at both edges of the distribution were found to be more vulnerable and responded in different ways to past climatic changes. These results illustrate how past climatic changes affected the demographic history of Himalayan organisms. Our findings highlight the significance of combining genomic approaches with environmental data when evaluating the effects of past climatic changes.

A large historical refugium explains spatial patterns of genetic diversity in a Neotropical savanna tree species.

BACKGROUND AND AIMS: The relative role of Pleistocene climate changes in driving the geographic distribution and genetic diversity of South American species is not well known, especially from open biomes such as the Cerrado, the most diverse tropical savanna, encompassing high levels of endemism. Here the effects of Quaternary climatic changes on demographic history, distribution dynamics and genetic diversity of Dimorphandra mollis, an endemic tree species widely distributed in the Cerrado, were investigated. METHODS: A total of 38 populations covering most of the distribution of D. mollis were analysed using internal transcribed spacer (ITS) sequences and nuclear microsatellite variation [simple sequence repeats (SSRs)]. The framework incorporated statistical phylogeography, coalescent analyses and ecological niche modelling (ENM). KEY RESULTS: Different signatures of Quaternary climatic changes were found for ITS sequences and SSRs corresponding to different time slices. Coalescent analyses revealed large and constant effective population sizes, with high historical connectivity among the populations for ITS sequences and low effective population sizes and gene flow with recent population retraction for SSRs. ENMs indicated a slight geographical range retraction during the Last Glacial Maximum. A large historical refugium across central Brazil was predicted. Spatially explicit analyses showed a spatial cline pattern in genetic diversity related to the paleodistribution of D. mollis and to the centre of its historical refugium. CONCLUSIONS: The complex genetic patterns found in D. mollis are the result of a slight geographical range retraction during the Last Glacial Maximum followed by population expansion to the east and south from a large refugium in the central part of the Cerrado. This historical refugium is coincident with an area predicted to be climatically stable under future climate scenarios. The identified refugium should be given high priority in conservation polices to safeguard the evolutionary potential of the species under predicted future climatic changes.

Demographical history and palaeodistribution modelling show range shift towards Amazon Basin for a Neotropical tree species in the LGM.

BACKGROUND: We studied the phylogeography and demographical history of Tabebuia serratifolia (Bignoniaceae) to understand the disjunct geographical distribution of South American seasonally dry tropical forests (SDTFs). We specifically tested if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the last glacial maximum (LGM), the so called South American dry forest refugia hypothesis, using ecological niche modelling (ENM) and statistical phylogeography. We sampled 235 individuals of T. serratifolia in 17 populations in Brazil and analysed the polymorphisms at three intergenic chloroplast regions and ITS nuclear ribosomal DNA. RESULTS: Coalescent analyses showed a demographical expansion at the last c. 130 ka (thousand years before present). Simulations and ENM also showed that the current spatial pattern of genetic diversity is most likely due to a scenario of range expansion and range shift towards the Amazon Basin during the colder and arid climatic conditions associated with the LGM, matching the expected for the South American dry forest refugia hypothesis, although contrasting to the Pleistocene Arc hypothesis. Populations in more stable areas or with higher suitability through time showed higher genetic diversity. Postglacial range shift towards the Southeast and Atlantic coast may have led to spatial genome assortment due to leading edge colonization as the species tracks suitable environments, leading to lower genetic diversity in populations at higher distance from the distribution centroid at 21 ka. CONCLUSION: Haplotype sharing or common ancestry among populations from Caatinga in Northeast Brazil, Atlantic Forest in Southeast and Cerrado biome and ENM evince the past connection among these biomes.

Toxicity of two pesticides in binary mixture on survival and enzymatic response of Cerastoderma edule - The warming influence.

Pesticide application increased by about 1 million tonnes in the last 3 decades. Pesticides' overuse, coupled with the need for several pesticides to control different pests in the same crop, and its application many times per year, results in dangerous chemical cocktails that enter in aquatic systems, with impacts to the ecosystems and its communities. Climatic changes are currently another great concern, is predicted by the end of the 21st century, the earth's surface temperature will increase by about 4 °C. Bivalve species are reported as essential to the ecosystems' balance. However, they are also indicated as the organisms that will suffer the most serious effects of the temperature increase. So, this work intends to: a) verify the harm of the sub-lethal concentrations of two worldwide used pesticides, oxyfluorfen and copper (Cu), when combined, to Cerastoderma edule at 15 °C and 20 °C; b) assess the changes in the antioxidant defence system, the activity of the neurological enzyme acetylcholinesterase and the nutritive value of C. edule, after exposure to sub-lethal concentrations of oxyfluorfen and Cu, single and in the mixture, at 15 °C and 20 °C; c) observe the interaction between Cu and oxyfluorfen, considering the different biomarkers. Bivalves were exposed to oxyfluorfen and Cu, single and combined, for 96 h, at 15 °C and 20 °C. Results showed lethal effects to the organisms exposed at 20 °C when exposed to the highest binary mixture concentrations. Biochemical effects were observed on the organisms exposed to 15 °C, despite not observing any lethal effects. Briefly, there was a reported increase in oxidative stress and a decrease in protein content, regardless of the increase in the activity of antioxidant enzymes. These results suggest the potentially dangerous effects of the chemicals' mixture combined with the temperature, on this species and its consumers, impacting the trophic chain, and consequently, the community structure and function.

Thermal bleaching in the northern South China Sea: impact of abnormal environment and climate on high-latitude coral reefs.

Extensive coral bleaching events can result in catastrophic degradation of coral reefs and reorganization of coral communities. In the present study, we analyzed the spatial differences in coral bleaching and possible reasons of large-scale coral bleaching, based on the results of a survey carried out in the northern South China Sea in 2020. In addition, we have continuously monitored the sea surface temperature (SST) of the northernmost Weizhou Island for more than six years. The living coral cover at Weizhou Island (W), Xuwen Nature Reserve (X), and Haihua Island (H) was relatively high at 24.6% ± 4.8%, 12.1% ± 3.8%, and 8.1% ± 2.6%, respectively, whereas their bleaching rates were 9.7% ± 2.6%, 9.7% ± 3.3%, and 6.9% ± 2.1%, respectively. Among them, the living coral cover of W was significantly different from those of X and H, whereas the bleaching rate was not significantly different among the three areas. In all three areas, the massive and encrusting corals predominate and exhibit relatively high bleaching rates, with Porites lutea and Bernardpora stutchburyi being the dominant species. In addition, the temperature monitoring results of Weizhou Island for six consecutive years showed that the critical SST of coral bleaching was 31.5 ℃. The monitoring results also showed that the average SST of Weizhou Island was 32.1 ℃, exceeding 32 ℃ in July 2020 for up to 533 h. The longest continuous time when the SST exceeded 32 ℃ was 97 h. These findings indicated that the coral bleaching event that occurred in the Beibu Gulf during 2020 was a large-scale and high-temperature transient event that presented a relatively homogeneous threat to the coral communities. We inferred that this sudden heat stress event was caused by the enclosed tidal current in the Beibu Gulf, which prevented the southern upwelling from reaching the north, as well as by the inability of the SST to decrease without rainfall caused by typhoon cyclones. Our findings suggested that abnormal heat waves can result in coral bleaching at high latitudes and even coral reef degradation. Furthermore, our study provides a new perspective for investigating the self-recovery and reorganization of coral communities following accumulated coral bleaching.

The sensitivity of innovative techniques for measuring low levels of radon in the environment using passive detectors.

In recent years, there has been a significant surge in interest in measuring low radon levels in the environment. These measurements are valuable, particularly for identifying radon priority areas as required by the European Council Directive 2013/59/EURATOM and for research related to climate change. Due to the limited sensitivity of existing radon detectors/monitors in addressing these challenges, substantial efforts have been devoted to developing new designs. This report compares the sensitivity of several innovative designs with that of existing passive radon monitors. These novel designs incorporate alpha track detectors, including large area low background detectors, with activated carbon fabric used as an efficient radon adsorber/radiator. Recent innovative solutions to mitigate the impact of temperature and humidity on detectors using adsorbers are also discussed. The background signal of detectors intended for use in these novel designs is examined, and their sensitivity is evaluated. The findings demonstrate that these novel designs have the potential to significantly enhance the sensitivity of long-term radon measurements, surpassing the detectors currently in widespread use by more than an order of magnitude.