Search Results (1,457)

Glaciers have been proposed as evolutionary hotspots for microbial evolution; however, direct evidence for glacial microbial population formation and genomic loci undergoing selective sweeps remains limited. To address this knowledge gap, we investigated the genomic diversity, evolutionary pressures, and adaptive strategies of Cryobacterium, a representative genus of glacier environments. Based on recent gene flow analysis, 18 distinct populations of Cryobacterium were identified, each exhibiting clear discontinuities in gene flow and genetic boundaries. Selective pressure analyses revealed purifying selection within populations, maintaining genetic stability, and positive selection between populations, suggesting adaptive divergence from environmental differences. Notably, half of the populations spanned geographically distant glaciers, suggesting widespread dispersal mechanisms such as atmospheric circulation or glacial fauna migrations. We identified 17 genes under strong selective sweeps, involved in metabolic enzymes, transporters, and gene regulation. Based on the reverse ecology principles, these genes (e.g., glucose-6-phosphate dehydrogenase assembly and RNA polymerase-binding gene), are likely to be critical for cold adaptation. This study provided clear genomic evidence of glacial microbial population formation driven by recent gene flow, significantly enhanced our understanding of microbial adaptation in extreme cold ecosystems, and emphasized the importance of deep genomic sequencing in ecological and evolutionary research. Full article

Kaolin is an abundant, low-cost filler for elastomeric compounds. The kaolin used here is primarily kaolinite, chemically clean, and contains a fine particle population. Although agglomeration is evident, it can be mitigated by appropriate physical processing and, when desired, by chemical coupling. This study evaluates kaolin in natural rubber (NR) and examines how adding bis(triethoxysilylpropyl) tetrasulfide (TESPT) during mixing affects filler–matrix compatibility, viscoelastic response, cure stability, and mechanical performance. Kaolin was structurally and morphologically characterized, and the compounds were prepared in a closed mixer coupled to a torque rheometer under controlled dispersion conditions. Part 1 assessed NR with kaolin without a coupling agent, and Part 2 assessed the NR–kaolin with TESPT added during mixing (0.5 and 5 phr). Small-amplitude oscillatory shear (SAOS) was used to probe viscoelastic behavior, while oscillating disk rheometry (ODR) and tensile tests quantified cure and mechanical properties. In Part 1, kaolin increased NR stiffness in SAOS and raised the 100% and 300% moduli by about 40% and 50%, respectively, relative to the unfilled NR compound, while reducing cure reversion from 30% to 10% at 150 °C. In Part 2, TESPT produced a threshold-like response: 0.5 phr caused only minor changes, whereas 5 phr led to pronounced stiffening and cure stabilization. At 5 phr, a low-frequency plateau in G′ below 0.1 Hz with no G′–G″ crossover was observed, accompanied by higher M_H and ΔM in ODR and reversion suppressed to 1% after 30 min. These trends indicate the formation of a more connected filler-rubber network, promoted by TESPT-assisted interfacial coupling/adhesion, while also reflecting the ability of TESPT (tetrasulfide) to contribute sulfur and modify the curing chemistry. Mechanically, kaolin produced marked stiffness increases, with the 100% and 300% moduli increasing by an additional 9% and 36%, respectively, at 5 phr TESPT. At the same time, ultimate tensile strength remained lower than that of neat NR, and elongation at break decreased slightly. Overall, adding TESPT during mixing enhances interfacial coupling and network connectivity and, at higher loading, also influences cure chemistry, yielding higher modulus and strongly improved reversion resistance without increasing ultimate tensile strength relative to neat NR. Full article

Community public sport facilities are core carriers of the national fitness public service system, with their supply–demand alignment directly linked to megacity governance efficiency and residents’ well-being. To address structural issues, such as “human–land imbalance” in facility layout, this study uses the 2010–2024 panel data from Shanghai’s 16 districts, applies supply–demand equilibrium theory, and integrates quantitative methods to analyze spatio-temporal supply–demand coupling and identify key influencing factors. The study yields four key findings: (1) The spatial distribution of facilities and population demonstrates a differentiated evolutionary trajectory marked by “central dispersion and suburban stability”. (2) Supply–demand alignment has continuously improved, as evidenced by the increase in coordinated administrative districts from six to thirteen. Nonetheless, the distance between sports facilities and population centers widened, suggesting that spatial adaptation remains incomplete. (3) Urban population growth exerts a significant positive impact on facility supply. Elasticity coefficients are generally high in suburban areas, while negative elasticity is detected in some central urban areas due to population outflow. (4) Facility construction intensity and residential activity intensity are core driving factors, with economic conditions, transportation infrastructure, and housing prices acting as key supporting factors. This study overcomes traditional aggregate-quantity research limitations, reveals megacity facility supply–demand “spatial mismatch” dynamics, and provides a scientific basis for targeted public sports facility layout and refined governance. Full article

The red fox (Vulpes vulpes) is a widely distributed and highly adaptive small carnivore known by its generalist diet, which includes small mammals, invertebrates, and fruits. Despite its ecological relevance, how habitat heterogeneity affects its diet across the Mediterranean, a biodiversity hotspot shaped by long-term human disturbance, remains insufficiently synthesized. In this review, we synthesized and analyzed published studies that reported habitat-specific data on the red fox diet in the Mediterranean. Only 12 studies met the selection criteria, and no study directly compared two different habitats. The studied areas covered three dominant habitats: forests, scrublands (garrigue), and agroecosystems, and diet items were grouped in 7 categories: birds, carcasses, fruits, invertebrates, lagomorphs, small mammals, and reptiles. Overall diet composition varied significantly, with invertebrates and fruits being the most frequent diet items. In turn, lagomorphs and reptiles were the least frequent. In turn, diet composition varied little across habitats, indicating that diet variation follows specific local resource abundance regardless of habitat type. Despite the analytical limitations associated with the limited availability of habitat-explicit studies. The results highlight the pronounced dietary plasticity of the red fox and its capacity to integrate resource availability across heterogeneous Mediterranean landscape mosaics. This trophic adaptability and top predator role support various ecosystem functions such as controlling invertebrate and small mammal populations, dispersing seeds, and cycling nutrients, reinforcing the potential of the red fox as functional bioindicator in the Mediterranean. Therefore, sustainable land management, especially in agricultural areas, and restoration efforts for degraded areas should consider the beneficial roles of generalist carnivores like the red fox. Full article

Cleisthenes herzensteini is a commercially important demersal fish in the Northwest Pacific. However, the resource stock of this species has undergone a drastic decline due to overfishing and habitat degradation. As a representative taxon for benthic adaptation in the order Pleuronectiformes, the molecular mechanisms underlying its specialized phenotypic traits remain poorly elucidated. Furthermore, population-level studies focusing on the mitochondrial genome of Cleisthenes herzensteini are currently scarce. Given that the mitochondrial genome serves as an ideal genetic tool for deciphering species evolution and population genetics, sequencing of its mitogenome will help fill critical gaps in genetic resources and provide essential support for species conservation and phylogenetic research. In this study, we sequenced, assembled, and annotated its complete mitochondrial genome. The circular mitogenome is 17,171 bp in length and exhibits a typical A + T bias (54.04%). Repeat sequence analysis identified 35 dispersed repeats. Codon usage analysis revealed that leucine was the most frequently encoded amino acid, with CUU being the preferred codon. Several protein-coding genes possessed incomplete stop codons (T--/TA-), and a nucleotide preference for A and C was observed at the third codon position. Phylogenetic reconstruction based on mitogenomes from 23 species supported the monophyly of the order Pleuronectiformes. C. herzensteini showed the closest relationship with Dexistes rikuzenius, forming a distinct clade alongside Hippoglossoides dubius and Limanda aspera. These results provide essential genetic resources for understanding the evolution and population genetics of C. herzensteini and related flatfishes. According to the investigation, this study represents the first report on the sequencing and analysis of the complete mitochondrial genome of the Cleisthenes herzensteini. This not only fills the gap in mitochondrial genetic information for this species but also provides a reference for subsequent investigations into the phylogenetic relationships and evolutionary processes within the family Pleuronectidae. Full article

Accurate information regarding species boundaries is essential for ecological research and conservation planning. This information is particularly difficult to obtain but essential for cryptic amphibian species. The distribution and potential dispersal corridors of two cryptic salamander species, the Korean clawed (Onychodactylus koreanus) and the Yangsan clawed (O. sillanus) salamanders, were investigated using integrated approaches for high-resolution species distribution modeling (SDM), genetic species identification, and habitat connectivity analysis. The SDM results showed high habitat suitability in mid- and high-mountainous areas, but very low suitability in riverine areas for both species. Genetic species identification of the 25 populations delimited the distribution boundary between the two species along the Nakdong and Geumho rivers. Dispersal corridors of the two species commonly involved a detour around the major rivers and produced only one possible dispersal route, where both species moved into the opposite species’ habitat along the east side of the mountainous areas of the Geumho River. The findings not only clarify the distribution range of two cryptic Onychodactylus species in the Republic of Korea but also highlight the importance of the unique dispersal route for studying species interactions and maintaining ecological connectivity. Full article

Based upon density functional theory (DFT) calculations, we present the basic electronic structure of CuPb₉(PO₄)₆O (Cu-doped lead apatite, aka LK-99), in two scenarios: (1) where the structure is constrained to the P3 symmetry and (2) where no symmetry is imposed. At the DFT level, the former is predicted to be metallic while the latter is found to be a charge-transfer insulator. In both cases the filling of these states is nominally $d^9$, consistent with the standard Cu²⁺ valence state, and Cu with a local magnetic moment of order 0.7 μ_B. In the metallic case we find these states to be unusually flat (∼0.2 eV dispersion), giving a very high density of electronic states (DOS) at the Fermi level that we argue can be a host for novel electronic physics. The flatness of the bands is the likely origin of symmetry-lowering gapping possibilities that would remove the spectral weight from $E_F$. Motivated by some initial experimental observations of metallic or semiconducting behavior, we propose that disorder (likely structural) is responsible for closing the gap. Here, we consider a variety of possibilities that could possibly close the charge-transfer gap but limit consideration to kinds of disorder that preserve electron count. Of the possible kinds we considered (spin disorder, O populating vacancy sites, and Cu on less energetically favorable Pb sites), the local Cu moment, and consequently the charge-transfer gap, remains robust. We conclude that disorder responsible for metallic behavior entails some kind of doping where the electron count changes. Further, we claim that the emergence of the flat bands should be due to weak wave function overlap between the orbitals on Cu and O sites, owing to the directional character of the constituent orbitals. Therefore, finding an appropriate host structure for minimizing hybridization between Cu and O while allowing them to still weakly interact should be a promising route for generating flat bands at $E_F$ which can lead to interesting electronic phenomena, regardless of whether LK-99 is a superconductor. Full article

Postsocialist peri-urban spaces are characterized by a chaotic development as a result of the transition from communism to capitalism. Recent research has highlighted that liveability in peri-urban spaces encounters challenges of adaptation to the peri-urban areas. The aim of the present study is to identify and analyze patterns and contrasts that occur between age groups and gender in relation to the level of liveability as well as to better understand the daily mobility practices and commuting dependencies and how mobility shapes key contrasts and emerging tensions within Timișoara’s postsocialist peri-urban spaces. As liveability relates to local development, commuting, and accessibility to service facilities in the residential environment, the identification of patterns and differences is imperative when considering the perception of local residents on potential (un)sustainable liveability in peri-urban areas. This study utilizes a quantitative analysis, informed by a survey of considerable size (N = 954) conducted in peri-urban settlements of Timisoara, Romania, with a view to elucidating the distinctions and commonalities in the perceptions held by the local populace. The findings indicate that the elderly population exhibits a greater reluctance to adapt to the emerging peri-urban environment. In contrast, the younger and more educated demographic demonstrates a higher degree of adaptability to the contemporary challenges posed by peri-urban expansion and hazardous development. Daily mobility, including commuting, is directly influenced by the effects of dispersed and chaotic development (e.g., more than 79% of respondents rely on private cars for commuting), as well as the lack of facilities and services (e.g., 2.21 level of satisfaction regarding cultural events). This highlights Timisoara’s dependence on external services, as well as the significant role of personal vehicles in providing access to the city center and its neighborhoods. Therefore, we can observe the peri-urban area undergoing a transitional phase as it navigates the initial stages of sustainable urban development and pursues an enhanced quality of life. Finally, we propose several policy recommendations for local authorities, offering solutions for enhancing liveability in peri-urban areas. Full article

Streptococcus uberis is a bovine mastitis pathogen with a demonstrated ability to form biofilms. However, the dynamics of this process remain poorly characterized. This study aimed to comprehensively characterize biofilm formation in four S. uberis strains that differed in their biofilm-forming capacity, from weak to strong producers, and in the presence of key virulence-associated genes, such as sua, hasA and hasC. To achieve this, we integrated structural, biochemical, physiological and transcriptional analyses using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), spectral flow cytometry and qRT-PCR. The multi-faceted analysis revealed a coordinated maturation peak at 48 h, characterized by a structured architecture with water channels, a distinct biochemical signature rich in polysaccharides and proteins, and a predominantly viable bacterial population. This peak coincided with a marked upregulation of key virulence-associated genes, with sua expression increasing 2.5-fold and hasA increasing 3-fold at 48 h. This mature biofilm conferred high tolerance to antibiotics, with eradication concentrations (>256 µg/mL) exceeding planktonic MICs, although tetracycline was notably effective. At 72 h, the biofilm entered a dispersion phase characterized by structural collapse and reduced viability. These findings establish S. uberis biofilm maturation as a highly coordinated process, providing new insights into the biofilm lifecycle of this important pathogen and identifying key temporal and molecular targets for future interventions. Full article

Plantations of the valuable Chinese timber species, Chamaecyparis hodginsii, established by planting, primarily rely on seed orchards for propagation. Therefore, effective management of the genetic composition of these orchards is essential to ensure a sustainable supply of high-quality seeds. However, the mating system and pollen dispersal mechanisms in its high-generation seed orchards remain unclear, limiting precise genetic management. To address this, we analyzed 30 parental clones and 75 of their open-pollinated progeny from a second-generation seed orchard using 15 polymorphic EST-SSR markers. Compared to reported natural populations of C. hodginsii, both parental and progeny populations maintained high genetic diversity (mean uHe = 0.438 and 0.449, respectively), with a significant excess of heterozygotes (mean Fis = −0.084 and −0.066, respectively). Population genetic structure analysis indicated weak genetic differentiation among the parental genetic groups (mean Fst = 0.012), which was further reduced in the progeny population (mean Fst = 0.003) due to open pollination, reflecting a trend toward genetic homogenization. The mating system was characterized exclusively by outcrossing (tm = 1.000). However, paternity analysis revealed highly skewed paternal contributions, a low effective number of pollen donors (Nep = 8.13), and contributions of S5, S11, and S17 as dominant pollen parents, with 17.33% external pollen flow. These findings elucidate the mechanisms underlying sustained genetic diversity despite unequal paternal contributions and provide a theoretical basis for optimizing parental configuration and pollen management. Full article

Nitrogen dioxide (NO₂) remains one of the most relevant traffic-related air pollutants in urban environments, despite decades of regulatory efforts and advances in vehicle emission control technologies. This review synthesizes current knowledge on ambient NO₂ concentrations associated with road transport, identifies key determinants of spatial and temporal variability, and evaluates the effectiveness of mitigation approaches under increasingly stringent air quality standards. The study is based on a comprehensive review of peer-reviewed literature reporting NO₂ measurements in urban, traffic, and background environments worldwide, complemented by an assessment of regulatory frameworks and mitigation strategies. The evidence confirms that road transport is the dominant contributor to elevated NO₂ concentrations, particularly at traffic sites, with traffic intensity, fleet composition, driving behavior, cold-start emissions, and street geometry emerging as primary controlling factors. Meteorological conditions influence dispersion but generally play a secondary role compared with emission-related drivers. Urban infrastructure, especially street canyons and tunnels, amplifies near-road NO₂ levels and population exposure. Mitigation measures such as Low Emission Zones, vehicle fleet modernization, and infrastructural interventions can reduce NO₂ concentrations, but their effectiveness is moderate and highly context-dependent. Sustained compliance with EU limit values and World Health Organization guideline levels requires integrated, multi-scale mitigation strategies. Full article

Delphastus Casey (Coleoptera: Coccinellidae: Serangiini) comprises small predatory ladybird beetles that feed on immature whiteflies. Several Delphastus species are utilized as biological control agents. However, Delphastus pallidus (LeConte) has been understudied for the past several decades. Recent landscape surveys in South Florida revealed a marked increase in D. pallidus populations associated with multiple whitefly species. We evaluated whitefly species preferences of D. pallidus using choice and no-choice assays conducted in incubators and insectaries. Seven whitefly species were confirmed as prey and ranked in order of preference: Bemisia tabaci Gennadius > Aleurothrixus trachoides (=Aleurotrachelus trachoides) (Back) > Singhiella simplex (Singh) > Paraleyrodes bondari Peracchi > Aleurodicus rugioperculatus Martin > Asiothrixus antidesmae (Takahashi) > Aleurodicus dugesii Cockerell. Findings indicate that D. pallidus feeds on a taxonomically and morphologically diverse set of whiteflies, including both waxy and non-waxy species, which likely facilitates establishment and dispersal in ornamental and agricultural landscapes. This study is the first to document D. pallidus as a potentially native U.S. predatory beetle that attacks at least seven whitefly species. Knowledge of its prey preferences will inform mass-rearing strategies and potential deployment for whitefly biocontrol. Full article

Human schistosomiasis is a neglected tropical disease caused by six Schistosoma species, the most widespread of which is S. mansoni. Despite its high prevalence in Africa, molecular data on the parasite remain scarce in many regions, including the Republic of Guinea. This study presents the first molecular characterization of S. mansoni from naturally infected Biomphalaria pfeifferi snails in Guinea. Eight cox1 and four nd5 mitochondrial gene fragments, 353–425 bp and 259–271 bp in length, respectively, were sequenced. A new cox1 haplotype of S. mansoni was identified in this study. High genetic diversity was observed in our samples for both cox1 (Hd = 0.75) and nd5 (Hd = 0.84). Phylogeographic analysis revealed that the dominant Guinean cox1 haplotypes are shared with other West African populations, and that one haplotype is globally dispersed, linking West Africa to South America and the Middle East. Phylogenetic reconstructions confirmed the divergence between West and Southeast African populations and supported the hypothesis of a Southeast African origin for S. mansoni, with a subsequent expansion to West Africa and the New World. These results highlight the importance of expanding molecular surveillance to improve our understanding of the spread and population structure of this human pathogen. Full article

Introduction: Rare diseases disperse expertise across institutions and borders, making structured second-opinion systems a pragmatic way to concentrate subspecialty knowledge and reduce diagnostic delays. This scoping review mapped the design, governance, adoption, and impacts of such services across implementation scales. Objectives: To describe how second-opinion services for rare diseases are organized and governed, to characterize technological and workflow models, to summarize benefits and barriers, and to identify priority evidence gaps for implementation. Methods: Using a population–concept–context approach, we included peer-reviewed studies describing implemented second-opinion systems for rare diseases and excluded isolated case reports, purely conceptual proposals, and work outside this focus. Searches in August 2025 covered PubMed/MEDLINE, Scopus, Web of Science Core Collection, Cochrane Library, IEEE Xplore, ACM Digital Library, and LILACS without date limits and were restricted to English, Portuguese, or Spanish. Two reviewers screened independently, and the data were charted with a standardized, piloted form. No formal critical appraisal was undertaken, and the synthesis was descriptive. Results: Initiatives were clustered by scale (European networks, national programs, regional systems, international collaborations) and favored hybrid models over asynchronous and synchronous ones. Across settings, services shared reproducible workflows and provided faster access to expertise, quicker decision-making, and more frequent clarification of care plans. These improvements were enabled by transparent governance and dedicated support but were constrained by platform complexity, the effort required to assemble panels, uneven incentives, interoperability gaps, and medico-legal uncertainty. Conclusions: Systematized second-opinion services for rare diseases are feasible and clinically relevant. Progress hinges on usability, aligned incentives, and pragmatic interoperability, advancing from registries toward bidirectional electronic health record connections, alongside prospective evaluations of outcomes, equity, experience, effectiveness, and costs. Full article

Deep-sea hydrothermal vent fauna is often regarded as highly endemic, although exceptions have been reported. We examined genetic connectivity across broad spatial scales within the alvinocaridid genus Rimicaris, which has undergone substantial adaptive radiation worldwide. We analyzed six Rimicaris species using three genetic markers, cytochrome c oxidase subunit I (COI), 16S ribosomal rRNA gene (16S), and histone h3 (H3), and complete mitogenomes, employing newly generated sequences combined with publicly available sequence data. A genetic tree and haplotype networks were constructed, and divergence analyses were performed. Three clades of paired Rimicaris species were identified, each made up of taxa from different oceanic regions but showing relatively low COI divergence (0.35–1.90%). In Clade I, Rimicaris chacei and Rimicaris hybisae are morphologically similar and exhibit bidirectional gene flow, implying a dispersal route between the Mid-Atlantic Ridge (MAR) and the Mid-Cayman Spreading Center (MCSC). In Clade II, Rimicaris exoculata and Rimicaris kairei are morphologically, genetically, and ecologically distinct, reflecting restricted connectivity between the MAR and the Carlsberg Ridge (CR)–Central Indian Ridge (CIR). In Clade III, Rimicaris variabilis and Rimicaris cf. variabilis differ in nutritional strategies, showing a unidirectional dispersal route from the CIR to the southwestern Pacific (SWP), but morphological data to distinguish them are currently lacking. Some Rimicaris lineages maintain connectivity across distinct oceanic regions while others still form unique regional populations. This finding highlights the need for conservation strategies that incorporate both global-scale connectivity and regional endemism, rather than treating individual vent ecosystems as a single homogeneous management unit. Full article