Non-invasive determination of critical dissolved oxygen thresholds for stress physiology in fish using triple-oxygen stable isotopes and aquatic respirometry.

Understanding the critical thresholds of dissolved oxygen (O2) that trigger adaptive physiological responses in aquatic organisms is long hampered by a lack of robust, non-lethal or non-invasive methodologies. The isotope fractionation of triple O2 isotopes (18O/17O/16O) during respiration is linked to the amount of oxygen utilised, offering a potential avenue for new insights. Our experimental research involved measuring the oxygen isotope fractionation of dissolved O2 in closed-system aquatic respirometry experiments with wild sticklebacks (Gasterosteus aculeatus). These fish were either naturally adapted or experimentally acclimated to hypoxic and normoxic conditions. The aim was to observe their oxygen usage and isotope fractionation in response to increasingly severe hypoxia. Initial observations revealed a progressive 18O enrichment from the preferential uptake of 16O to a dissolved oxygen threshold of 3-5 mg O2 L-1, followed by an apparent reversal in oxygen isotope fractionation, which is mixing of 16O and 17O with the remaining O2 pool across all populations and indicative of a systematic change in oxygen metabolism among the fish. Unexpectedly, sticklebacks adapted to hypoxia but acclimated to normoxia exhibited stronger oxygen isotope fractionation compared to those adapted to normoxia and acclimated to hypoxia, contradicting the hypothesis that hypoxia adaptation would lead to reduced isotope discrimination due to more efficient oxygen uptake. These preliminary experimental results highlight the novel potential of using dissolved O2 isotopes as a non-invasive, non-lethal method to quantitatively assess metabolic thresholds in aquatic organisms. This approach could significantly improve our understanding of the critical oxygen responses and adaptation mechanisms in fish and other aquatic organisms across different oxygen environments, marking a significant step forward in aquatic ecological and physiological research.

Genome-wide comparative analyses highlights selection signatures underlying saline adaptation in Chilika buffalo.

Chilika, a native buffalo breed of the Eastern coast of India, is mainly distributed around the Chilika brackish water lake connected with the Bay of Bengal Sea. This breed possesses a unique ability to delve deep into the salty water of the lake and stay there to feed on local vegetation of saline nature. Adaptation to salinity is a genetic phenomenon, however, the genetic basis underlying the salinity tolerance is still limited in animals specifically in livestock. The present study explores the genetic evolution that unveils the Chilika buffalo's adaptation to the harsh saline habitat (water and food system). For this study, whole genome resequencing data on 18 Chilika buffalo and for comparison 10 Murrah buffalo of normal habitat were generated. For identification of selection sweeps, intrapopulation and interpopulation statistics were employed. A total of 709, 309, 468, and 354 genes were detected having selection sweeps in Chilika buffalo using the nucleotide diversity (θπ), Tajima's D, nucleotide diversity ratio (θπ-ratio), and FST methods, respectively. Further analysis revealed a total of 23 genes including EXOC6B, VPS8, LYPD1, VPS35, CAMKMT, NCKAP5, COMMD1, MYLK3, B3GNT2 were found to be common by all the methods. Furthermore, functional annotation study of identified genes provided pathways such as MAPK signaling, renin secretion, endocytosis, oxytocin signaling pathway, etc. Gene network analysis enlists hub genes, provide insights into their interactions with each other. In conclusion, this study has highlighted the genetic basis underlying the local adaptive function of Chilika buffalo under saline environment.

Comparison of joint kinematics between upright front squat exercise and horizontal squat exercise performed on a short arm human centrifugation.

This study compared the joint kinematics between the front squat (FS) conducted in the upright (natural gravity) position and in the supine position on a short arm human centrifuge (SAHC). Male participants (N = 12) with no prior experience exercising on a centrifuge completed a FS in the upright position before (PRE) and after (POST) a FS exercise conducted on the SAHC while exposed to artificial gravity (AG). Participants completed, in randomized order, three sets of six repetitions with a load equal to body weight or 1.25 × body weight for upright squats, and 1 g and 1.25 g at the center of gravity (COG) for AG. During the terrestrial squats, the load was applied with a barbell. Knee (left/right) and hip (left/right) flexion angles were recorded with a set of inertial measurement units. AG decreased the maximum flexion angle (MAX) of knees and hips as well as the range of motion (ROM), both at 1 and 1.25 g. Minor adaptation was observed between the first and the last repetition performed in AG. AG affects the ability to FS in naïve participants by reducing MAX, MIN and ROM of the knees and hip.

The diet-intestinal microbiota dynamics and adaptation in an elevational migration bird, the Himalayan bluetail (Tarsiger rufilatus).

Migratory birds experience changes in their environment and diet during seasonal migrations, thus requiring interactions between diet and gut microbes. Understanding the co-evolution of the host and gut microbiota is critical for elucidating the rapid adaptations of avian gut microbiota. However, dynamics of gut microbial adaptations concerning elevational migratory behavior, which is prevalent but understudied in montane birds remain poorly understood. We focused on the Himalayan bluetail (Tarsiger rufilatus) in the montane forests of Mt. Gongga to understand the diet-gut microbial adaptations of elevational migratory birds. Our findings indicate that elevational migratory movements can rapidly alter gut microbial composition and function within a month. There was a significant interaction between an animal-based diet and gut microbiota across migration stages, underscoring the importance of diet in shaping microbial communities. Furthermore, the gut microbial composition of T. rufilatus may be potentially altered by high-altitude acclimatization. An increase in fatty acid and amino acid metabolism was observed in response to low temperatures and limited resources, resulting in enhanced energy extraction and nutrient utilization. Moreover, microbial communities in distinct gut segments varied in relative abundance and responses to environmental changes. While the bird jejunum exhibited greater susceptibility to food and environmental fluctuations, there was no significant difference in metabolic capacity among gut segments. This study provides initial evidence of rapid diet-gut microbial changes in distinct gut segments of elevational migratory birds and highlights the importance of seasonal sample collection. Our findings provide a deeper understanding of the unique high-altitude adaptation patterns of the gut microbiota for montane elevational migratory birds.

Growth-defense trade-offs promote habitat isolation between recently-diverged species.

Trade-offs are crucial for species divergence and reproductive isolation. Trade-offs between investment in growth versus defense against herbivores are implicated in tropical forest diversity. Empirically exploring the role of growth-defense trade-offs in closely related species' reproductive isolation can clarify the eco-evolutionary dynamics through which growth-defense trade-offs contribute to diversity. Costus villosissimus and C. allenii are recently diverged, interfertile, and partially sympatric neotropical understory plant species primarily isolated by divergent habitat adaptation. This divergent adaptation involves differences in growth rate, which may constrain investment in defense. Here, we investigate growth-defense trade-offs and how they relate to the divergent habitat adaptation that isolates these species. We characterize leaf toughness and chemistry, evaluate the feeding preferences of primary beetle herbivores in controlled trials and field-based experiments, and investigate natural herbivory patterns. We find clear trade-offs between growth and defense: slower-growing C. allenii has tougher leaves and higher defensive chemical concentrations than faster-growing C. villosissimus. Costus villosissimus has rapid growth-based drought avoidance, enabling growth in drier habitats with few specialist herbivores. Therefore, growth-defense trade-offs mediate synergistic biotic and abiotic selection, causing the divergent habitat adaptation that prevents most interspecific mating between C. villosissimus and C. allenii. Our findings advance understanding of ecological speciation by highlighting the interplay of biotic and abiotic selection that dictates the outcome of trade-offs.

Converging forms: an examination of sub-Arctic, circumarctic, and Central Asian Ranunculus auricomus agg. populations.

Introduction: Phenotypic complexity in species complexes and recently radiated lineages has resulted in a diversity of forms that have historically been classified into separate taxa. Increasingly, with the proliferation of high-throughput sequencing methods, additional layers of complexity have been recognized, such as frequent hybridization and reticulation, which may call into question the previous morphological groupings of closely related organisms. Methods: We investigated Northern European, Asian, and Beringian populations of Ranunculus auricomus agg. with phylogenomic analysis of 736 genes and 27,586 SNPs in order to deduce the interrelatedness and hybrid origin of this phenotypically and taxonomically complicated group from Europe characterized by a history of hybridization, polyploidy, apomixis, and recent radiation. The ploidy levels and the reproductive mode of the Northern European populations were assessed via flow cytometric seed screening. In addition, in order to examine the phenotypic plasticity of the dwarf forms previously described as species and summarized as the Ranunculus monophyllus group, we conducted climate chamber experiments under cold (northern) and warm (temperate) conditions. Results: The Northern European populations are tetra- to hexaploid and propagate primarily through apomixis. The complex is characterized by highly reticulate relationships. Genetic differentiation of the main clusters has occurred between the above-mentioned geographical regions. We find evidence for the hybrid origin of the taxa in these areas with differing genomic contributions from the geographically nearest European sexual progenitor species. Furthermore, polyphyly in the taxa of the R. monophyllus group is supported. Experiments show low lability in the traits associated with the R. monophyllus group. Discussion: We conclude that multiple adaptations of hybrids to colder climates and shorter vegetation periods have shaped the phenotypes of the R. monophyllus group, and we suggest a formal classification as nothotaxa within the R. auricomus group.

Lipidomics of homeoviscous adaptation to low temperatures in Staphylococcus aureus utilizing exogenous straight-chain unsaturated fatty acids.

It is well established that Staphylococcus aureus can incorporate exogenous straight-chain unsaturated fatty acids (SCUFAs) into membrane phospho- and glyco-lipids from various sources in supplemented culture media and when growing in vivo during infection. Given the enhancement of membrane fluidity when oleic acid (C18:1Δ9) is incorporated into lipids, we were prompted to examine the effect of medium supplementation with C18:1Δ9 on growth at low temperatures. C18:1Δ9 supported the growth of a cold-sensitive, branched-chain fatty acid (BCFA)-deficient mutant at 12°C. Interestingly, we found similar results in the BCFA-sufficient parental strain, supported by the fact that the incorporation of C18:1Δ9 into the membrane increased membrane fluidity in both strains. We show that the incorporation of C18:1Δ9 and its elongation product C20:1Δ11 into membrane lipids was required for growth stimulation and relied on a functional FakAB incorporation system. Lipidomics analysis of the phosphatidylglycerol and diglycosyldiacylglycerol lipid classes revealed major impacts of C18:1Δ9 and temperature on lipid species. Growth at 12°C in the presence of C18:1Δ9 also led to increased production of the carotenoid pigment staphyloxanthin. The enhancement of growth by C18:1Δ9 is an example of homeoviscous adaptation to low temperatures utilizing an exogenous fatty acid. This may be significant in the growth of S. aureus at low temperatures in foods that commonly contain C18:1Δ9 and other SCUFAs in various forms. IMPORTANCE: We show that Staphylococcus aureus can use its known ability to incorporate exogenous fatty acids to enhance its growth at low temperatures. Individual species of phosphatidylglycerols and diglycosyldiacylglycerols bearing one or two degrees of unsaturation derived from the incorporation of C18:1Δ9 at 12°C are described for the first time. In addition, enhanced production of the carotenoid staphyloxanthin occurs at low temperatures. The studies describe a biochemical reality underlying membrane biophysics. This is an example of homeoviscous adaptation to low temperatures utilizing exogenous fatty acids over the regulation of the biosynthesis of endogenous fatty acids. The studies have likely relevance to food safety in that unsaturated fatty acids may enhance the growth of S. aureus in the food environment.

Bio-inspired compensatory strategies for damage to flapping robotic propulsors.

Natural swimmers and flyers can fully recover from catastrophic propulsor damage by altering stroke mechanics: some fish can lose even 76% of their propulsive surface without loss of thrust. We consider applying these principles to enable robotic flapping propulsors to autonomously repair functionality. However, direct transference of these alterations from an organism to a robotic flapping propulsor may be suboptimal owing to irrelevant evolutionary pressures. Instead, we use machine learning techniques to compare these alterations with those optimal for a robotic system. We implement an online artificial evolution with hardware-in-the-loop, performing experimental evaluations with a flexible plate. To recoup thrust, the learned strategy increased amplitude, frequency and angle of attack (AOA) amplitude, and phase-shifted AOA by approximately 110°. Only amplitude increase is reported by most fish literature. When recovering side force, we find that force direction is correlated with AOA. No clear amplitude or frequency trend is found, whereas frequency increases in most insect literature. These results suggest that how mechanical flapping propulsors most efficiently adjust to damage may not align with natural swimmers and flyers.

Competitive interactions affect introgression and population viability amidst maladaptive hybridization.

The deliberate release of captive-bred individuals, the accidental escape of domesticated strains, or the invasion of closely related conspecifics into wild populations can all lead to introgressive hybridization, which poses a challenge for conservation and wildlife management. Rates of introgression and the magnitude of associated demographic impacts vary widely across ecological contexts. However, the reasons for this variation remain poorly understood. One rarely considered phenomenon in this context is soft selection, wherein relative trait values determine success in intraspecific competition for a limiting resource. Here we develop an eco-genetic model explicitly focussed on understanding the influence of such competitive interactions on the eco-evolutionary dynamics of wild populations experiencing an influx of foreign/domesticated individuals. The model is applicable to any taxon that experiences natural or human-mediated inputs of locally maladapted genotypes ('intrusion'), in addition to phenotype-dependent competition for a limiting resource (e.g. breeding sites, feeding territories). The effects of both acute and chronic intrusion depended strongly on the relative competitiveness of intruders versus locals. When intruders were competitively inferior, density-dependent regulation limited their reproductive success (ability to compete for limited spawning sites), which prevented strong introgression or population declines from occurring. In contrast, when intruders were competitively superior, this amplified introgression and led to increased maladaptation of the admixed population. This had negative consequences for population size and population viability. The results were sensitive to the intrusion level, the magnitude of reproductive excess, trait heritability and the extent to which intruders were maladapted relative to locals. Our findings draw attention to under-appreciated interactions between phenotype-dependent competitive interactions and maladaptive hybridization, which may be critical to determining the impact captive breeding programmes and domesticated escapees can have on otherwise self-sustaining wild populations.

Source-free domain adaptation for semantic image segmentation using internal representations.

Semantic segmentation models trained on annotated data fail to generalize well when the input data distribution changes over extended time period, leading to requiring re-training to maintain performance. Classic unsupervised domain adaptation (UDA) attempts to address a similar problem when there is target domain with no annotated data points through transferring knowledge from a source domain with annotated data. We develop an online UDA algorithm for semantic segmentation of images that improves model generalization on unannotated domains in scenarios where source data access is restricted during adaptation. We perform model adaptation by minimizing the distributional distance between the source latent features and the target features in a shared embedding space. Our solution promotes a shared domain-agnostic latent feature space between the two domains, which allows for classifier generalization on the target dataset. To alleviate the need of access to source samples during adaptation, we approximate the source latent feature distribution via an appropriate surrogate distribution, in this case a Gaussian mixture model (GMM).

The cross-cultural adaptation of Chinese international students: an empirical study on sequential-mediated effects.

Using convenience sampling and snowball sampling methods, data from 432 Chinese international students in 10 countries, including the United Kingdom, South Korea, and the United States, were collected to construct a multivariate sequential-mediated mixed model for cross-cultural adaptation. SPSS 23.0 and AMOS 23.0 were employed for aggregated validity, discriminant validity, and sequential-mediated effects analysis. The study found that: Cultural adaptation stress is negatively correlated with positive coping and positively correlated with negative coping, with negative coping having a significant negative impact during the cross-cultural adaptation process. Positive coping is positively correlated with sports participation, while negative coping is negatively correlated with sports participation. Sports participation is positively associated with in-group identification and negatively associated with out-group bias. In-group identification has a positive impact on cross-cultural adaptation, whereas out-group bias cannot effectively predict cross-cultural adaptation.

Investigating the acidophilic microbial community's adaptation for enhancement indium bioleaching from high pulp density shredded discarded LCD panels.

As part of electronic waste (e-waste), the fastest growing solid waste stream in the world, discarded liquid crystal displays (LCDs) contain substantial amounts of both valuable and potentially harmful metal, offering valuable opportunities for resource extraction but posing environmental threats. The present comprehensive study is an investigation into the bioleaching of indium from discarded LCD panels, with a particular focus on high pulp density shredded (Sh-LCDs) and powdered (P-LCDs) materials. This study involved an acidophilic consortium, with two pathways, namely the mixed sulfur-iron pathways and sulfur pathways, being explored to understand the bioleaching mechanisms. Indium bioleaching efficiencies through the mixed sulfur-iron pathway were approximately 60% and 100% for Sh-LCDs and P-LCDs, respectively. Three mechanisms were involved in the extraction of indium from LCD samples: acidolysis, complexolysis, and redoxolysis. The microbial community adapted to a pulp density of 32.5 g/L was streak-plated and it was revealed that sulfur-oxizing bacteria dominated, resulting in the minimum indium extraction of 10% and 55% for both Sh-LCDs and P-LCDs samples, respectively. It was generally accepted that ferric ions as oxidants were effective for indium bioleaching from both the Sh-LCDs and P-LCDs. This implies that the cooperation or interaction within the microbial community used in the bioleaching process had a beneficial impact, enhancing the overall effectiveness of extracting indium from LCD panels. The adapted consortium utilizes a combination of microbial transformation, efflux systems, and chelation through extracellular substances to detoxify heavy metals. The adapted microbial community demonstrated better indium leaching efficiency (50%) compared to the non-adapted microbial community which achieved a maximum of 29% and 5% respectively from Sh-LCDs and P-LCDs at a pulp density of 32.5 g/L. The advantages of an adapted microbial community for indium leaching efficiency, attributing this advantage to factors such as high metabolic activity and improved tolerance to heavy metals. Additionally, the protective role of the biofilm formed by the adapted microbial community is particularly noteworthy, as it contributes to the community's resilience in the presence of inhibitory substances. This information is valuable for understanding and optimizing bioleaching processes for indium recovery, and by extension to possibly other metals.

Correlation between the Colony Phenotype and Amino Acid Sequence of the Variable Vaa Antigen in Clinical Isolates of Mycoplasma hominis.

A new Mycoplasma hominis phenotype forming mini-colonies (MC) on agar and distinct from the phenotype forming typical colonies (TC) not only in size, but also in morphology, growth rate, and resistance to adverse factors, has been previously identified. In this study, the phenotype of colonies was determined and a comparative analysis of the amino acid sequence of the main variable antigen Vaa of the laboratory strain N-34 and seven clinical isolates of M. hominis was performed. It is demonstrated that the amino acid sequence of Vaa in clinical isolates forming TC (similar to the laboratory strain N-34) is entirely analogous to that of laboratory strain. Clinical isolates forming MC carry amino acid substitutions in the variable C-terminal region of Vaa, which can contribute to adhesion to eukaryotic cells and immune evasion. The connection between colony phenotype and amino acid sequence of Vaa is established.

Design Principles for Perfect Adaptation in Biological Networks with Nonlinear Dynamics.

Establishing a mapping between the emergent biological properties and the repository of network structures has been of great relevance in systems and synthetic biology. Adaptation is one such biological property of paramount importance that promotes regulation in the presence of environmental disturbances. This paper presents a nonlinear systems theory-driven framework to identify the design principles for perfect adaptation with respect to external disturbances of arbitrary magnitude. Based on the prior information about the network, we frame precise mathematical conditions for adaptation using nonlinear systems theory. We first deduce the mathematical conditions for perfect adaptation for constant input disturbances. Subsequently, we translate these conditions to specific necessary structural requirements for adaptation in networks of small size and then extend to argue that there exist only two classes of architectures for a network of any size that can provide local adaptation in the entire state space, namely, incoherent feed-forward (IFF) structure and negative feedback loop with buffer node (NFB). The additional positiveness constraints further narrow the admissible set of network structures. This also aids in establishing the global asymptotic stability for the steady state given a constant input disturbance. The proposed method does not assume any explicit knowledge of the underlying rate kinetics, barring some minimal assumptions. Finally, we also discuss the infeasibility of certain IFF networks in providing adaptation in the presence of downstream connections. Moreover, we propose a generic and novel algorithm based on non-linear systems theory to unravel the design principles for global adaptation. Detailed and extensive simulation studies corroborate the theoretical findings.

Drivers of genomic diversity and phenotypic development in early phases of domestication in Hermetia illucens.

The black soldier fly (BSF), Hermetia illucens, has the ability to efficiently bioremediate organic waste into usable bio-compounds. Understanding the impact of domestication and mass rearing on fitness and production traits is therefore important for sustainable production. This study aimed to assess patterns of genomic diversity and its association to phenotypic development across early generations of mass rearing under two selection strategies: selection for greater larval mass (SEL lines) and no direct artificial selection (NS lines). Genome-wide single nucleotide polymorphism (SNP) data were generated using 2bRAD sequencing, while phenotypic traits relating to production and population fitness were measured. Declining patterns of genomic diversity were observed across three generations of captive breeding, with the lowest diversity recorded for the F3 generation of both selection lines, most likely due to founder effects. The SEL cohort displayed statistically significantly greater larval weight com the NS lines with pronounced genetic and phenotypic directional changes across generations. Furthermore, lower genetic and phenotypic diversity, particularly for fitness traits, were evident for SEL lines, illustrating the trade-off between selecting for mass and the resulting decline in population fitness. SNP-based heritability was significant for growth, but was low or non-significant for fitness traits. Genotype-phenotype correlations were observed for traits, but individual locus effect sizes where small and very few of these loci demonstrated a signature for selection. Pronounced genetic drift, due to small effective population sizes, is likely overshadowing the impacts of selection on genomic diversity and consequently phenotypic development. The results hold particular relevance for genetic management and selective breeding for BSF in future.

Clothing color effect as a target of the smallest scale climate change adaptation.

The purpose of this study is to understand a physical mechanism to determine the surface temperature of clothes in calm and fine conditions of outdoors. We observed surface temperatures of polo shirts of the same material and design but different colors. The shirts were placed in unshaded and well-ventilated outdoor, open spaces on sunny summer days. The maximum difference between dark green or black and white was more than 15 °C during calm, fine weather and was greatest when the solar radiation was strong. If the transmission of solar radiation energy through a shirt is ignored to calculate the absorption by the shirt, the difference in solar radiation absorption due to different colors is as much as 24% in the maximum, and if considered, we concluded that an absorption difference of 34% led to a temperature difference of 15℃. When we compared the brightness of the colors, we found that the albedo of both the visible and NIR bands explained why the red and green colors were so different with respect to the surface temperatures we observed. The reflection in the NIR bands was also an important determinant of the surface temperature. An additional experiment using masks showed that the temperature difference between white and black was almost eliminated at a wind speed of ~ 3 m/s. The color of clothing is therefore a target for small-scale adaptation to climate change.

Genome sequencing of Coryphaenoides yaquinae reveals convergent and lineage-specific molecular evolution in deep-sea adaptation.

Abyssal (3501-6500 m) and hadal (>6500 m) fauna evolve under harsh abiotic stresses, characterized by high hydrostatic pressure, darkness and food shortage, providing unique opportunities to investigate mechanisms underlying environmental adaptation. Genomes of several hadal species have recently been reported. However, the genetic adaptation of deep sea species across a broad spectrum of ocean depths has yet to be thoroughly investigated, due to the challenges imposed by collecting the deep sea species. To elucidate the correlation between genetic innovation and vertical distribution, we generated a chromosome-level genome assembly of the macrourids Coryphaenoides yaquinae, which is widely distributed in the abyssal/hadal zone ranging from 3655 to 7259 m in depth. Genomic comparisons among shallow, abyssal and hadal-living species identified idiosyncratic and convergent genetic alterations underlying the extraordinary adaptations of deep-sea species including light perception, circadian regulation, hydrostatic pressure and hunger tolerance. The deep-sea fishes (Coryphaenoides Sp. and Pseudoliparis swirei) venturing into various ocean depths independently have undergone convergent amino acid substitutions in multiple proteins such as rhodopsin 1, pancreatic and duodenal homeobox 1 and melanocortin 4 receptor which are known or verified in zebrafish to be related with vision adaptation and energy expenditure. Convergent evolution events were also identified in heat shock protein 90 beta family member 1 and valosin-containing protein genes known to be related to hydrostatic pressure adaptation specifically in fishes found around the hadal range. The uncovering of the molecular convergence among the deep-sea species shed new light on the common genetic innovations required for deep-sea adaptation by the fishes.

A Chromosome-level Genome Assembly Provides Insights into the Local Adaptation of Tamarix austromongolica in the Yellow River Basin, China.

Tamarix austromongolica is endemic to the Yellow River Basin and has adapted to diverse ecological settings in the region, including the arid areas of northwestern China and the saline soil regions of the Yellow River Delta. However, the genetic basis of its local adaptation remains unclear. We report a chromosome-level assembly of the T. austromongolica genome based on PacBio high-fidelity sequencing and Hi-C technology. The 12 pseudochromosomes cover 98.44% of the 1.32 Gb assembly, with a contig N50 of 52.57 Mb and a BUSCO score of 98.2%. The genome comprises 913.6 Mb (68.83%) of repetitive sequences and 22,374 protein-coding genes. Genome evolution analyses suggest that genes under positive selection and significantly expanded gene families have facilitated T. austromongolica's adaptability to diverse environmental factors and high resistance to diseases. Using genotyping-by-sequencing, we conducted population structure and selection analyses of 114 samples from 15 sites. Two genetic groups were identified, and 114 and 289 candidate genes were assigned to the populations of the northwestern and eastern parts of the Yellow River, respectively. Furthermore, we discovered numerous candidate genes associated with high-altitude adaptability and salt tolerance. This research provides valuable genomic resources for the evolutionary study and genetic breeding of tamarisk.

More efficient adaptation of cardiovascular response to repeated restraint in spontaneously hypertensive rats: the role of autonomic nervous system.

We hypothesized that sympathetic hyperactivity and parasympathetic insuficiency in spontaneously hypertensive rats (SHR) underlie their exaggerated cardiovascular response to acute stress and impaired adaptation to repeated restraint stress exposure compared to Wistar-Kyoto rats (WKY). Cardiovascular responses to single (120 min) or repeated (daily 120 min for 1 week) restraint were measured by radiotelemetry and autonomic balance was evaluated by power spectral analysis of systolic blood pressure variability (SBPV) and heart rate variability (HRV). Baroreflex sensitivity (BRS) was measured by the pharmacological Oxford technique. Stress-induced pressor response and vascular sympathetic activity (low-frequency component of SBPV) were enhanced in SHR subjected to single restraint compared to WKY, whereas stress-induced tachycardia was similar in both strains. SHR exhibited attenuated cardiac parasympathetic activity (high-frequency component of HRV) and blunted BRS compared to WKY. Repeated restraint did not affect the stress-induced increase in blood pressure. However, cardiovascular response during the post-stress recovery period of the 7th restraint was reduced in both strains. The repeatedly restrained SHR showed lower basal heart rate during the dark (active) phase and slightly decreased basal blood pressure during the light phase compared to stress-naive SHR. SHR subjected to repeated restraint also exhibited attenuated stress-induced tachycardia, augmented cardiac parasympathetic activity, attenuated vascular sympathetic activity and improved BRS during the last seventh restraint compared to single-stressed SHR. Thus, SHR exhibited enhanced cardiovascular and sympathetic responsiveness to novel stressor exposure (single restraint) compared to WKY. Unexpectedly, the adaptation of cardiovascular and autonomic responses to repeated restraint was more effective in SHR.

Environmental and social framework to protect marine bivalves under extreme weather events.

Rising ocean temperatures, a consequence of anthropogenic climate change, are increasing the frequency, intensity, and magnitude of extreme marine heatwaves (MHWs). These persistent anomalous warming events can have severe ecological and socioeconomic impacts, threatening ecologically and economically vital organisms such as bivalves and the ecosystems they support. Developing robust environmental and social frameworks to enhance the resilience and adaptability of bivalve aquaculture is critical to ensuring the sustainability of this crucial food source. This review synthesizes the current understanding of the physiological and ecological impacts of MHWs on commercially important bivalve species farmed globally. We propose an integrated risk assessment framework that encompasses environmental monitoring, farm-level preparedness planning, and community-level social support systems to safeguard bivalve aquaculture. Specifically, we examine heatwave prediction models, local mitigation strategies, and social programs that could mitigate the impacts on bivalve farms and vulnerable coastal communities economically dependent on this fishery. At the farm level, adaptation strategies such as selective breeding for heat-tolerant strains, optimized site selection, and adjustments to culture practices can improve survival outcomes during MHWs. Robust disease surveillance and management programs are essential for early detection and rapid response. Furthermore, we highlight the importance of stakeholder engagement, knowledge exchange, and collaborative governance in developing context-specific, inclusive, and equitable safeguard systems. Proactive measures, such as advanced forecasting tools like the California Current Marine Heat Wave Tracker developed by NOAA's Southwest Fisheries Science Center, enable preemptive action before losses occur. Coordinated preparation and response, underpinned by continuous monitoring and adaptive management, promise to protect these climate-vulnerable food systems and coastal communities. However, sustained research, innovation, and cross-sector collaboration are imperative to navigate the challenges posed by our rapidly changing oceans.