Search Results (1,934)

Mammillaria parkinsonii and M. perbella are species endemic to the Queretano–Hidalguense Desert (QHD), a potential globose cacti Pleistocene refuge. We tested if the phylogeographic and genetic structures of these species are temporally consistent with the Pleistocene glacial refuge hypothesis. In this case, there would be high haplotype divergence associated with population contraction during the Last Glacial period (115-11.7 kya). Chloroplast DNA sequences and ISSR nuclear markers were used to estimate genetic diversity and structure, haplotype networks, and divergence times. Changes in paleodistribution were modeled using the Ecological Niche Model (MNE). cpDNA and ISSR markers revealed low-to-moderate genetic diversity in M. pakinsonii and M. perbella (π = 0.0004, 0.0044 respectively; H_S = 0.362–0.434, 0.293–0.400, respectively) and high population differentiation (G_ST = 1, 0.722, respectively; Φ_ST = 0.378, 0.3957, respectively), with no evidence of gene flow (Nm = 0, 0.29, respectively). The estimated divergence times and MNE showed that population divergence began during the Last Glacial in M. perbella and continued into the Holocene for both species. This divergence is associated with population contraction, geographic isolation, and disruption of gene flow. This joint evidence indicated that Pleistocene–Holocene glacial cycles may have driven the recent divergence of these Mammillaria species in the QHD. Full article

Vernal ponds are temporary, isolated bodies of water that lack vertebrate predators like fish. Palmer Park in Detroit, MI, USA, contains an old-growth forest with multiple vernal ponds that are home to numerous invertebrates, including water mites, which are the main focus of this study. These vernal ponds are unique since they are geographically isolated in the middle of an urban landscape. Previous research discovered new species of non-biting midges in Palmer Park vernal ponds, suggesting the potential for the discovery of previously undocumented organisms and relationships in this ecosystem. Here we document the invertebrate species found in the vernal ponds of Palmer Park, both to illustrate their diversity and to determine their cytochrome oxidase I (COI) barcode sequences. COI barcode sequences are used in this study to verify identification and provide reference sequences for comparison to sequences in the diets of water mites also collected from the ponds. Three taxa of water mites found in Palmer Park Pond A are Hydryphantes waynensis, Parathyas sp., and Hydryphantes sp. (distinct from H. waynensis by having a COI barcode sequence 11.6% different from Hydryphantes sp.). This paper also uses Next Generation Sequencing (NGS) to analyze the complex diets of the water mites at Palmer Park. The diets consisted of a diversity of species of oligochaetes, mosquitoes, non-biting midges, crustaceans, flies, and beetles. Beetles identified as whole organisms in the ponds or from diet-detected bar codes in vernal pond water mites include Copelatus glyphicus, Acilius sp., and Hygrotus sayi. The diets of water mites in these vernal ponds are compared to previous molecular studies in which water mites in a riverine lagoon were identified as opportunistic predators of a diverse invertebrate diet. Beetle DNA was consistently detected in association with water mites, suggesting a potential and previously unreported dietary or ecological interaction; however, alternative explanations such as external contamination by environmental DNA or secondary ingestion cannot be excluded. Beetles have not previously been reported in water mite diets, so this finding represents a new discovery. This molecular analysis revealed taxa and novel COI barcode sequences not observed through traditional sampling, highlighting the value of water mites for community characterization. These results support the hypothesis that water mites are opportunistic predators, uniquely reports beetles as putative components of their diets, and emphasizes their ecological importance and utility in assessing vernal pond biodiversity. Full article

Foam cells are central to atherosclerotic plaque development, but their pathological significance in advanced lesions extends beyond lipid accumulation. Under chronic exposure to oxidized lipoproteins, cholesterol crystals, inflammatory cytokines, hypoxia, lysosomal stress, and mitochondrial injury, lipid-loaded foam cells of macrophage and vascular smooth muscle cell (VSMC) origin may acquire maladaptive stress phenotypes. In this focused review, we propose a redox-threshold model, defined as the transition point at which mitochondrial antioxidant and metabolic buffering capacity is exceeded, allowing lipid peroxide accumulation to shift senescence-like foam cells toward ferroptosis susceptibility and defective plaque resolution. Progressive mitochondrial reactive oxygen species (ROS) accumulation, impaired NADPH-dependent antioxidant buffering, defective glutathione and thioredoxin recycling, mitophagy impairment, and reduced GPX4-mediated lipid peroxide detoxification may converge to promote iron-dependent lipid peroxidation. If lipid-peroxidized or dying foam cells are not efficiently cleared, oxidized lipids, cellular debris, and inflammatory signals accumulate, promoting secondary necrosis, necrotic core expansion, plaque non-resolution, and instability. We explicitly distinguish established processes from mechanistically supported inferences and hypothesis-generating links, emphasizing that the complete senescence-like stress-to-ferroptosis-to-non-resolution sequence remains a testable framework rather than an established linear pathway. This focused framework suggests that advanced plaque stabilization may require strategies that preserve mitochondrial redox resilience, limit ferroptotic lipid peroxidation, and enhance efferocytosis-mediated resolution. Full article

Background/Objectives: Bacterial colonization is an under-recognized component of antimicrobial resistance (AMR), particularly among cardiovascular outpatients who frequently interact with healthcare services. While surveillance has traditionally focused on multidrug-resistant (MDR) pathogens causing clinical infection, the ecological characteristics of colonization including multisite carriage, polymicrobial communities, and commensal or low-virulence organisms recovered on antimicrobial-containing media remain poorly defined. This study investigated the burden and ecological patterns of colonization by organisms with reduced antimicrobial susceptibility in cardiovascular outpatients. Methods: In this cross-sectional study, 36 adult cardiovascular outpatients were screened using sputum, nasal, and skin specimens (108 samples) on antimicrobial-supplemented selective media. Isolates were identified by MALDI-TOF mass spectrometry, susceptibility was determined using the VITEK 2 system, and colonization patterns were analyzed using exact statistical methods. Results: Colonization by organisms with reduced antimicrobial susceptibility was detected in 61.1% of patients (95% CI, 44.9–75.2), and at least one validated MDR pathogen in 52.8% (95% CI, 37.0–68.0). Sputum showed the highest colonization prevalence. Multisite colonization occurred in 72.7% of colonized patients, with 40.9% positive at all three anatomical sites. Polymicrobial colonization was common (mean 1.9 species per colonized patient). Resistant commensal bacteria including Neisseria flavescens, Neisseria mucosa, Moraxella catarrhalis, and Lacticaseibacillus casei were recovered alongside recognized pathogens and showed reduced susceptibility across multiple antibiotic classes. Colonization showed significant concordance across anatomical sites, indicating a whole-body colonization state rather than a series of independent site events. Prior hospitalization and concurrent antibiotic therapy were significantly associated with colonization, whereas prior percutaneous coronary intervention and individual comorbidities were not. Conclusions: Cardiovascular outpatients frequently harbour complex bacterial communities characterized by multisite colonization, polymicrobial carriage, commensal and low-virulence organisms recovered on selective media, and MDR pathogens. These findings highlight bacterial colonization as a potential community reservoir of AMR and support targeted pre-procedural screening together with community antimicrobial stewardship. As a single-centre, cross-sectional study of 36 patients, these results are exploratory and hypothesis-generating and require confirmation in larger, multicentre cohorts. Full article

Reliable spatial evidence can support quality assurance and quality control for land use, land-use change and forestry (LULUCF), but land-cover and species-distribution layers do not by themselves identify IPCC Forest Land or species-pure stands. We estimated 2010 and 2020 above- and below-ground living biomass carbon within tree-covered European beech (Fagus sylvatica L.) distribution and occurrence footprints in Greece. Our operational hypothesis was that increasingly restrictive species masks would materially alter the mapped extent and carbon estimates. ESA Climate Change Initiative Biomass v6, ESA WorldCover 2021, European Forest Genetic Resources Programme (EUFORGEN) polygons, and Forest Information System for Europe (FISE) relative probability of presence layers were processed in Google Earth Engine. Biomass was converted with IPCC default carbon fractions and root:shoot ratios, and the results were summarized nationally and for GAUL Level-2 units. The broad EUFORGEN footprint covered 22,133 km², whereas the Combined overlap of EUFORGEN, FISE relative probability of presence ≥ 0.50, and tree cover covered 2742 km². Within the Combined footprint, the pixel mean living biomass carbon density was 60.33 Mg C ha⁻¹ in 2010 and 62.50 Mg C ha⁻¹ in 2020, and the area-integrated change was +0.58 Tg C; the area-normalized regional change was positive in 13 of 17 units and negative in 4. Across masks, the mean decadal change ranged from −0.50 to +3.37 Mg C ha⁻¹ and the approximate area-integrated totals from −1.10 to +0.58 Tg C. These scenario-conditioned estimates are neither official national greenhouse gas inventory estimates nor tests of statistical significance; instead, they provide reproducible spatial screening while making mask sensitivity and unpropagated uncertainty explicit. Full article

Endometrial senescence and the endometrial microbiota have both been implicated in the regulation of endometrial receptivity, yet their relationship remains poorly understood. The aim of this study was to investigate associations between p16-positive endometrial cells and microbiota composition during the implantation window and to determine whether these relationships differ according to implantation outcome. Endometrial senescence was assessed by p16 immunohistochemistry and digital image analysis, whereas microbial composition was characterized by 16S rRNA gene sequencing in endometrial biopsies collected from 68 women prior to undergoing transfer of a single euploid embryo, which was performed within six months of biopsy under the same hormonal preparation protocol. No significant differences in luminal epithelial or stromal p16 abundance were observed according to subsequent implantation outcome. Although senescence was not directly associated with implantation success, stromal p16 expression demonstrated multiple associations with the endometrial microbiota. Increased stromal p16-positivity was associated with lower relative abundance of Lactobacillus and higher abundance of Delftia. Notably, in exploratory subgroup analyses more pronounced associations were observed in women who achieved pregnancy, including a negative correlation between stromal p16 expression and Lactobacillus abundance (ρ = −0.48, p = 0.005) and positive correlation with Delftia abundance (ρ = 0.42, p = 0.016). Species-level analyses revealed implantation outcome-specific associations involving Lactobacillus iners and Limosilactobacillus vaginalis. In addition, stromal p16 expression was associated with differences in microbial co-occurrence networks, indicating broader effects on microbial community organization. Together, these findings suggest that stromal, but not luminal, senescence is closely linked to endometrial microbiota composition and microbial community organization during the window of implantation. The observation that the strongest senescence–microbiota associations occurred in women who subsequently achieved successful implantation supports the hypothesis that coordinated senescence–microbiota relationships may represent a previously underrecognized feature of the receptive endometrial microenvironment. Full article

Pressure ulcers are a major clinical problem in patients with severe immobility; however, their pathophysiology extends beyond mechanical pressure and localized ischemia. Repetitive ischemia–reperfusion promotes sustained reactive oxygen species (ROS) production, leading to persistent inflammation, mitochondrial dysfunction, metabolic stress, and chronic wound refractoriness. In this review, we propose the ROS Gatekeeper Hypothesis, in which a ROS-dominant redox microenvironment functions as the central determinant of signaling permissiveness for gaseous signaling molecules. Within this framework, nitric oxide (NO) serves as the principal redox-responsive signaling axis, whereas hydrogen sulfide (H2S) and carbon monoxide (CO) function as complementary redox-responsive modulators whose biological effects depend on the surrounding redox environment. Under ROS-dominant conditions, NO bioavailability is reduced through superoxide scavenging and endothelial nitric oxide synthase (eNOS) uncoupling, while progressive oxidative stress is proposed to drive a transition toward a redox-constrained state in which responsiveness to all three gasotransmitters becomes increasingly limited. Accordingly, therapeutic efficacy is proposed to depend on preservation or restoration of signaling permissiveness rather than gasotransmitter abundance alone. The ROS Gatekeeper Hypothesis provides a unified conceptual framework for interpreting heterogeneous therapeutic responses and guiding future stage-specific, redox-oriented therapeutic strategies for chronic wounds. Full article

Soil fungi play a key role in nutrient cycling and soil organic matter turnover, yet the influence of pedological context on fungal communities across forest types remains insufficiently understood. Here, we combined soil chemical analyses, Fourier-transform infrared spectroscopy (FTIR), and ITS2 metabarcoding to investigate soil properties and fungal communities in temperate mountain beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst) forests in Italy developed on contrasting geological substrates. Soil horizons were sampled across seasons to characterize the main associations between fungal community structure, inferred functional diversity, and environmental context. Soil chemistry revealed site- and horizon-dependent patterns, particularly in pH, Ca, and P availability, whereas differences related to dominant tree species were comparatively limited. FTIR spectra showed clear variation in organic matter composition among sites, consistent with site- and stand-associated differences in organic matter composition. Fungal community composition was primarily associated with site and soil horizon. Functional guild patterns suggested ectomycorrhizal dominance in Ca-rich soils and greater prevalence of saprotrophs in more acidic soils. Overall, this multi-proxy approach suggests that pedological context was more closely associated with fungal community structure and ecological strategies than with vegetation type or season within the studied stands. These patterns should be interpreted as site-specific and hypothesis-generating because substrate types were not replicated across independent locations. Full article

The electrochemical regeneration of sodium borohydride (NaBH₄) from spent metaborate is a central bottleneck for circular hydrogen storage. (1) Background: The eight-electron reduction of the aqueous borate species B(OH)₄⁻ to BH₄⁻ is thermodynamically out-competed by the hydrogen-evolution reaction (HER) by about 0.41 V at every pH, so selectivity can only be won kinetically. (2) Methods: We advance an ambiphilic-site hypothesis, screen 30 candidate metal centres using entirely experimental, tabulated descriptors (bulk HER exchange current density; gas-phase M-O bond energy) with no new electronic-structure computation, and then audit the transferability of both descriptor axes against published, corrected DFT datasets for nitrogen-coordinated single-atom sites. (3) Results: At the parent-metal level, the two axes are orthogonal (Spearman ρ = 0.02) and the score passes a family-level experimental validation over seven bulk-electrode metals (ρ = 0.69; exact permutation p = 0.050), separating the HER-dominated noble-metal family from the single-atom Mn benchmark. The site-level audit shows that the oxophilicity axis transfers to M-N₄ sites almost quantitatively (ρ = −0.84 pyridine-4N, −0.95 pyrrole-4N, n = 23) while the bulk HER axis does not, and that site-level scaling between oxygen and hydrogen binding narrows the productive window to oxophilic centres that over-bind hydrogen. (4) Conclusions: The site-anchored screen redirects the search from the parent-metal leaders (La, Ce, Y, Ti, Sc) to refractory single-atom centres, with W, Nb and Mo as priority synthesis targets (Re excluded on scarcity; Zr, Hf, Ta as data-supported extensions; Ti as the sustainability-anchored borderline case) and the lanthanides retained only as explicitly extrapolative candidates. All data and analysis code are openly deposited. Full article

One of the leading drivers of biodiversity loss is land use change due to the ever-increasing demand for food, livestock feed, biofiber, and biofuel. The concept of human appropriation of net primary production (HANPP) was developed to measure the impact that humans have on the environment by accounting for biomass removed from the environment in the form of crops, timber, and grazing. The species–energy hypothesis is an established ecological hypothesis postulating that greater species diversity is correlated with higher levels of energy from plant productivity; this can be measured as net primary production minus harvested HANPP or NPP_ecological. Theoretically, a “biodiversity footprint” could be developed by estimating the reduction in species associated with a volume of biomass extraction, reducing NPP_eco. Achieving this would be an advance in sustainability science. We used the USGS Gap Analysis Project (GAP) dataset for bird species diversity and a unique mapping of HANPP_harvest (from crops, grazing, and timber harvests) at the scale of counties in the conterminous US to test whether HANPP reduces bird species richness. Negative binomial regression finds, however, that HANPP_harvest is only a marginally statistically significant stressor of bird species richness. A secondary measure of NPP_ecological/HANPP_harvest is similarly a marginally significant positive predictor. Consistent with recent literature emphasizing the need to account for spatial autocorrelation in ecological research, however, both HANPP_harvest and NPP_ecological/HANPP_harvest are insignificant predictors of bird diversity in the conterminous US at the county scale when spatial autocorrelation, along with county size and coastal adjacency, are accounted for. We conclude that species richness is determined by a complex set of factors that render using data on HANPP to develop a biodiversity footprint speculative and imprecise in the case of bird species richness in the US. Full article

Neonatal candidemia remains a major cause of morbidity and mortality in neonatal intensive care units, particularly among preterm and very-low-birth-weight infants. This retrospective cohort study evaluated the clinical characteristics, microbiological profiles, and factors associated with 28-day all-cause mortality in neonates with culture-proven candidemia admitted to a tertiary neonatal intensive care unit between January 2011 and December 2025. Demographic, clinical, microbiological, treatment, feeding, and outcome data were collected from medical records, and factors associated with mortality were analyzed using univariate and multivariable Firth-penalized logistic regression. A total of 48 neonates were included, with a median gestational age of 28 weeks (IQR 25–36) and a median birth weight of 967.5 g (IQR 765–2400). The incidence of candidemia was 0.4%. Candida albicans was the most frequently isolated species (66.7%). The 28-day all-cause mortality rate was 47.9% (23/48). Non-survivors had lower gestational age and birth weight and developed candidemia earlier than survivors. In the univariable analysis, breast milk exposure before the onset of candidemia was significantly more common among survivors than among nonsurvivors and should be considered a hypothesis-generating finding. In the multivariable analysis, inotropic support (aOR 14.69, 95% CI 2.66–124.74; p = 0.001) and thrombocytopenia (aOR 5.91, 95% CI 1.36–34.44; p = 0.017) were independently associated with 28-day all-cause mortality. In this cohort, inotropic support and thrombocytopenia were independently associated with 28-day all-cause mortality, whereas the association between breast milk exposure and survival was limited to the univariable analysis. Full article

Meat tenderness is a critical quality trait that varies even among carcasses of similar USDA quality grades. In this comparative study of beef cattle and sheep, we investigated how gene expression profiles in muscle and adipose tissues are associated with carcass quality grades and Fat Classes. Fifteen steers and fifteen wethers were raised to produce carcasses spanning Standard, Select, and Choice USDA quality grades (beef) or varying Fat Classes (sheep). In beef, higher quality grade was associated with significantly improved tenderness (lower shear force), while sheep tenderness did not differ consistently across Fat Classes. Exploratory RNA sequencing identified hundreds to thousands of differentially expressed genes (DEGs) between high- and low-quality or fatness groups, particularly in sheep muscle. DEGs were enriched in pathways related to muscle growth, lipid metabolism, and immune signaling. While these transcriptomic differences suggest biological processes associated with carcass traits, the findings are correlational, should be interpreted as hypothesis-generating, and require further validation in larger independent populations. These exploratory findings suggest species-specific differences in the relationship between fatness and tenderness and identify candidate molecular pathways for future investigation. Full article

Background/Objectives: The White-tailed Sea-eagle, Haliaeetus albicilla, experienced severe population declines throughout Europe during the nineteenth and twentieth centuries, followed by a remarkable recovery in recent decades. Although the genetic structure of northern and central European populations has been extensively investigated, the phylogeographic history and contribution of the lower Danube population to the mitochondrial genetic diversity of the species remain poorly understood. Methods: We analyzed mitochondrial control region (MT-CR HVR1) sequences from White-tailed Sea-eagles breeding in the Danube Delta Biosphere Reserve (DDBR) and integrated these data with previously published sequences covering the species’ distribution across Europe and Asia; a total of 480 samples were examined. Results: The analysis revealed 47 haplotypes, including 11 haplotypes unique to the DDBR population. Phylogeographic analyses support the Scandinavian Peninsula as the ancestral source area of the species, followed by an early colonization of Central Europe and subsequent expansion into the Balkan Peninsula through the Danube corridor. The Romanian population exhibited the highest haplotype diversity among the investigated regions (Hd = 0.9367) and was characterized by numerous private haplotypes and a predominance of haplogroup C (approximately 76% of individuals), which was rare or absent in most northern and central European populations. Demographic analyses revealed significant evidence of recent population expansion following historical bottlenecks (Fu’s Fs = −5.736, p = 0.006), whereas gene-flow estimates indicated only moderate connectivity with neighbouring Balkan and Central European populations. Conclusions: The high frequency of private haplotypes, the absence of significant isolation-by-distance patterns, and the distinct distribution of mitochondrial haplogroups, characterized by the predominance of haplogroup C, suggest that the current DDBR population may have originated primarily through local demographic recovery rather than recent large-scale recolonization. Our results indicate that the lower Danube region represents an important reservoir of genetic diversity and support the hypothesis that the Danube Delta may have acted as a potential secondary refugium and center of diversification for H. a. in southeastern Europe. Full article

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host. Research has traditionally focused on bacterial species, particularly Lacticaseibacillus and Bifidobacterium, whose mechanisms are well-characterised. However, probiotic yeasts represent a functionally distinct category, with Saccharomyces boulardii as the most studied representative and Kluyveromyces marxianus as an emerging candidate. Bacterial and yeast probiotics differ in cell biology, antibiotic susceptibility, immune receptor engagement, and metabolic output. Bacterial strains provide mucosal adhesion and direct short-chain fatty acid (SCFA) generation but are susceptible to antibacterial therapy. Yeast strains are intrinsically antibiotic-resistant, offer enzymatic activities such as β-galactosidase and glycosidases, and exert indirect bifidogenic effects that amplify luminal SCFA concentrations beyond what either category achieves alone. These non-overlapping profiles support a complementary rather than competitive conceptualisation of their use. When combined with prebiotic substrates such as fructooligosaccharides or galactooligosaccharides, this integrated approach addresses the principal axes of intestinal homeostasis more comprehensively than any single-organism intervention. Prospective randomised trials are needed to determine whether this mechanistic complementarity translates into additive or synergistic clinical benefit. This review synthesises the available evidence and proposes a framework for their complementary use. The proposed framework is hypothesis-generating: it rests largely on mechanistic and preclinical data, and its clinical validity requires confirmation in adequately powered controlled trials. Full article

Mantidae exhibits the most extensive adaptive radiation within the order Mantodea; however, studies elucidating their internal phylogenetic relationships and spatio-temporal diversification patterns remain scarce. This study aims to resolve the long-standing taxonomic uncertainties within Mantidae by testing the hypothesis that the polyphyletic nature of several subfamilies—specifically Tenoderinae and Hierodulinae—is linked to an incomplete understanding of their mitochondrial genomic evolution. To address this, we assembled 16 complete Mantodea mitochondrial genomes, including seven representatives of the tribe Archimantini (Mantidae: Hierodulinae). Of these, 10 mitogenomes conform to the ancestral insect mitochondrial gene order proposed by Cameron and colleagues, but six mitochondrial gene orders do not conform to the ancestral insect mitochondrial gene order. We identified typical mantodean mitochondrial rearrangement patterns in three species, characterized by gene duplications within the trnA-trnR-trnN-trnS-trnE-trnF and CR-trnI-trnQ-trnM-trnM-ND2 gene cluster. Phylogenetic analyses corroborate the monophyly of Orthoderinae, Mantinae, Choeradodinae, Vatinae, and Archimantini within Mantidae; conversely, Tenoderinae and Hierodulinae are resolved as polyphyletic assemblages. Divergence time estimation indicates that the split between extant Mantodea and Blattodea occurred during the Middle Permian (275.4 Ma, 95% HPD: 207.07–329.09 Ma). Mantidae originated during the Late Cretaceous (87.83 Ma, 95% HPD: 58.89–118.23 Ma), with the diversification of most subfamilies of Mantidae occurring during the Late Cretaceous (80.48 Ma; 95% HPD: 54.86–106.41 Ma). Historical biogeographic analysis and the estimated divergence times suggests that the common ancestor of Mantidae originated within Gondwana during the Late Cretaceous. Ancestral range reconstructions identify Australasia realms and Neotropical realms as the most probable center of origination for Mantidae and achieved a global distribution by expanding along the trans-Antarctic route and leveraging the ‘Indian Ark’ effect. Full article