Search Results (890)

Horses were widely distributed in North America during the Pleistocene epoch and their fossil remains are common in sedimentary deposits of this age. Despite their rich fossil record, the systematics and taxonomy of North American Pleistocene horses remain unresolved. We evaluated a large sample of cranial and postcranial horse fossils of Irvingtonian and Rancholabrean North American Land Mammal Age. In this study, we present Part 1 of our evaluation, which centers on caballine horses, Equus (Equus). We present data (measurements and photographs) and analyses (Simpson’s ratio diagrams, scatter diagrams, and anatomical comparisons) that reveal morphological variation in North American caballine horses. These analyses serve as the basis for recognizing different morphospecies: E. (E.) scotti, E. (E.) alaskae, E. (E.) lambei (the latter two possibly representing “ecological variants” of a single species), E. (E.) niobrarensis, E. (E.) pacificus, and E. (E.) complicatus. How these morphospecies (or chronospecies or ecological variants) were phylogenetically related remains to be evaluated. Equus (E.) hatcheri may be considered as a morphological variant or chronological variant of E. (E.) niobrarensis. Equus holmesi is considered a junior synonym of E. (E.) scotti, while E. bautistensis may be regarded as a junior synonym of E. (E.) pacificus. Equus laurentius is a junior synonym of E. (E.) caballus, a synonymy proposed previously in other studies. We are uncertain about the nature of E. midlandensis. In addition, we identify morphometric and anatomical features that distinguish between Equus (Equus), North American Equus (Amerhippus), and Equus (Hesperohippus) mexicanus. This study aims to advance our understanding of the taxonomy of North American Pleistocene horses, providing a thoroughly documented catalogue as a basis for further studies. Full article

Urticaria is a skin disorder characterized by erythematous, edematous, and pruritic lesions. Intestinal microorganisms can trigger various immunological responses, and Blastocystis has been suggested to affect gut-associated lymphoid tissue homeostasis and induce allergic reactions. This study aimed to evaluate the effect of Blastocystis on the intestinal microbiota in patients with urticaria. A total of 33 patients diagnosed with urticaria and 34 healthy controls were included. Independent sample t-tests, Welch’s t-tests, or Mann–Whitney U tests were applied to assess differences in the Shannon, Simpson, and Chao-1 indices between groups. Significant differences were observed in Proteobacteria (p = 0.015), Bacteroidetes (p = 0.008), Escherichia (p = 0.005), Phocaelcola (p = 0.043), and Prevotella (p = 0.047) between the urticaria and control groups. Bacteroidetes (p = 0.003) and Phocaelcola (p = 0.032) also differed significantly between samples with and without Blastocystis. Overall microbiota composition showed a significant difference between Blastocystis-positive and -negative samples (p = 0.009). The Firmicutes/Bacteroidetes ratio was 4.1 in healthy controls and 6.4 in urticaria patients. In conclusion, both urticaria and Blastocystis infection significantly influence intestinal microbiota composition, suggesting a potential interaction between Blastocystis colonization and host immune regulation in urticaria. Full article

The grasslands and shrublands of northern and central Mexico cover nearly 25% of the country and harbor high biodiversity. However, they are increasingly degraded by agriculture, urbanization, infrastructure development, and water overexploitation. To assess the status of medium- and large-sized mammals in these threatened ecosystems, we quantified species richness, relative abundance, and naïve occupancy across vegetation types and seasons. From April 2023 to February 2024, monthly track surveys and camera trapping were performed, and the data were analyzed in R. We documented 16 species representing four orders and nine families, with Carnivora being the most diverse (eight species). The species richness varied by habitat, ranging from 11 in montane forest to 13 in semi-desert grassland, the latter habitat having the highest Shannon and Simpson indices, particularly in the dry season. Odocoileus virginianus and Sylvilagus audubonii were consistently the most abundant species in montane forest and desert scrub, whereas Cynomys mexicanus predominated in semi-desert grasslands, accounting for >90% of detections during the rainy season. Rare species included Lynx rufus, Taxidea taxus, and Ursus americanus, each with isolated detections. Rarefaction and sample coverage curves approached asymptotes (>99%), indicating sufficient sampling effort. Naïve occupancy and encounter rates were highest for O. virginianus (0.82) and S. audubonii (0.68), with a strong positive correlation between the two metrics (r² = 0.92). These findings provide robust baseline information on mammalian diversity, abundance, and habitat associations in semi-arid anthropogenic landscapes, supporting future monitoring and conservation strategies. Full article

Persistent diarrhea remains a significant cause of morbidity in young children, yet the role of gut microbiota has not been fully clarified. This prospective study evaluated the diversity and predicted functions of the gut microbiota in 30 children aged 6–24 months with persistent diarrhea of unknown etiology (patient group, PG) and 30 healthy controls (healthy group, HG). Nearly full-length 16S rRNA genes from fecal bacterial metagenomic DNA were sequenced and taxonomically annotated. Subsequently, all downstream analyses, including diversity assessment, differential abundance and functional prediction analyses, and data visualization, were performed using R software (version 4.5.0, 2025). The PG showed lower Shannon and higher Simpson indices than the HG (p < 0.05), reflecting reduced microbial diversity. At the phylum level, Firmicutes predominated in the PG, whereas Actinobacteriota, Bacteroidota, and Verrucomicrobiota were more abundant in the HG (|log₂FC| > 1 and FDR < 0.05). At the genus and species levels, the PG exhibited a marked depletion of essential commensals such as Bifidobacterium longum, Faecalibacterium, Lactobacillus, and Eubacterium, alongside an enrichment of opportunistic taxa including Klebsiella, Enterococcus lactis, and Streptococcus spp. (FDR < 0.05). Functional predictions using PICRUSt2 indicated an enrichment of carbohydrate metabolism and reductions in amino acid metabolism, B-vitamin pathways, and the biosynthesis of endogenous antibiotics (FDR < 0.05). These findings suggest that the PG harbors a dysbiotic gut microbiota characterized by reduced diversity, depletion of key commensal taxa, expansion of opportunistic bacteria, and potentially adverse shifts in metabolic functions. Full article

Northern artificial forests play a vital role in enhancing carbon sequestration and ecosystem services, yet quantitative evidence on how different management measures affect understory biodiversity and productivity remains limited. This study focused on Larix gmelinii var. principis-rupprechtii (Mayr) Pilg. plantations in Weichang, Hebei Province, and compared three forest management regimes: target-tree management, homogeneous management, and un-managed stands. We systematically examined understory plant diversity indices (Shannon, Simpson, Margalef, Gleason, and Pielou), shrub–herb layer biomass, soil organic carbon (SOC), and total nitrogen (TN), and employed correlation analysis and random forest modeling to identify the main driving factors. Results showed that target-tree management significantly enhanced both understory biodiversity and shrub–herb biomass, followed by homogeneous management, while unmanaged stands had the lowest values. Differences in SOC and TN among treatments were not significant. Stand structural factors were the dominant drivers: stand density and basal area were negatively correlated with diversity and biomass, while community evenness (Pielou) was positively correlated with biomass. Random forest analysis further indicated that basal area and stand density had the highest relative importance, followed by evenness, whereas soil factors contributed less. Mechanistically, target-tree management improved light availability and spatial distribution by reducing stand density, thereby increasing evenness and promoting biomass accumulation. Overall, optimizing stand structure, rather than merely increasing species richness, proved more effective in simultaneously enhancing biodiversity and productivity in light-limited Larix plantations. From a management perspective, target-tree management combined with density regulation and structural optimization is recommended to achieve near-natural management goals and enhance multiple ecological functions. Full article

Mastitis continues to impose considerable economic losses on the dairy industry; however, the epidemiological characteristics and genetic diversity of Nocardia cyriacigeorgica remain poorly characterized. In the present study, two large-scale Chinese dairy farms experiencing mastitis outbreaks were investigated, with a total of 666 milk and 288 environmental samples collected. From the milk samples, 85 isolates of N. cyriacigeorgica were identified, corresponding to detection rates of 22.7% in clinical mastitis, 11.2% in subclinical mastitis, and 28.0% in healthy milk. Whole genome sequencing combined with multilocus sequence analysis demonstrated markedly limited genetic diversity, with the majority of isolates clustering within a few closely related lineages (Simpson’s Index: 0.12 for clinical and 0.037 for subclinical samples). Furthermore, qPCR screening detected N. cyriacigeorgica in 21.9% of environmental samples, with the highest detection frequencies observed on nasal swabs (62.5%), teat skin (56.3%), interdigital spaces (56.3%), and milking equipment (45.8%). Taken together, these findings are consistent with shared environmental exposure within farms and suggest a role for persistent reservoirs in repeated cow exposure. This investigation provides a comprehensive characterization of the population structure and distribution of N. cyriacigeorgica in Chinese dairy herds and underscores the importance of environment-focused management strategies for reducing infection pressure and enhancing mastitis control. Full article

Transgenic Bt maize commercialization has become a critical pest management strategy against lepidopteran insects in southwest China, but its ecological impact on arthropod biodiversity remains insufficiently characterized. This two-year field investigation (2023–2024) conducted in Bazhong City, Sichuan Province utilized systematic field monitoring to compare arthropod community dynamics between conventional maize and Bt-Cry1Ab maize (DBN9936) cultivation systems. This study documented 575,970 arthropod specimens representing 80 species/types across 45 families and 17 orders. Analysis of variance revealed significant differences (p < 0.05) between non-Bt and Bt maize in the abundance and species richness of target herbivorous pests, non-target herbivorous pests, and natural enemy insects. Field investigations revealed a notable absence of Macrocentrus cingulum, a key larval parasitoid of Ostrinia furnacalis, in Bt-maize plots compared to conventional counterparts. The populations of non-target herbivorous pests and natural enemies such as Aphididae, Chrysoperla sinica, Frankliniella tenuicornis, and Orius sauteri were higher in Bt maize fields than in non-Bt maize fields, while the populations of target herbivorous pests including O. furnacalis and Mythimna loreyi were lower than those in non-Bt maize fields. However, no significant differences (p > 0.05) were observed in arthropod abundance, species richness, or in a suite of ecological indices including the Simpson diversity index, Shannon–Wiener diversity index, Pielou evenness index, McIntosh diversity index, and community stability indices (N_n/N_p, N_d/N_p, and S_d/S_p). Redundancy analysis identified maize growth stages (6.75% variance explained) and interannual variations (2.44%) as principal drivers of arthropod community dynamics, with maize genotype contributing minimally (1.53%). These findings demonstrate that Bt-Cry1Ab maize (DBN9936) cultivation maintains functional arthropod community structure while effectively controlling target pests, providing substantial empirical evidence to support its sustainable deployment in southern China’s agricultural landscapes. Full article

Agricultural landscapes often exhibit low tree cover and homogeneity, leading to various environmental challenges. Traditional farmsteads, as scattered built environments in agricultural landscapes with diverse woody vegetation, enhance ecological heterogeneity and provide significant ecosystem services (ES), yet their dendroflora remains understudied. This study assesses woody vegetation on ten traditional farmsteads in Vojvodina, Serbia as case studies, through field surveys of woody species, biodiversity indices, GIS-based spatial analyses, and classification of species according to functional and ecosystem-related traits, offering insights into ecological patterns within these landscapes. The analysis examines species composition, abundance, origin, structural traits (tree cover, density, age, height, and crown width), and functional roles in ES provision. The vegetation shows potential to contribute to ES, especially through melliferous species (about 80%), food sources (about 82% for humans; 91% for birds, 91% for small mammals, 87% for domestic animals), and windbreak functions (about 76%). Phytoncide-producing species (about 62%) suggest a potential provision of air quality benefits, while entomophilous species (about 83%) indicate a potential provision of pollination support. Traditional farmsteads support biodiversity conservation, habitat provision, and preservation of genetic resources, particularly through old and rare species. Integrating these systems into agroforestry and biodiversity-friendly practices may increase ecological resilience and balance in intensive farming areas. Recognising traditional farmsteads as biodiversity reservoirs is vital for sustainable land use, and for conserving cultural and natural heritage within agricultural landscapes. Full article

Improving growth and health at weaning remains a priority in pig production. This study investigates whether supplementation with galacto-oligosaccharides (GOSs) followed by xylo-oligosaccharides (XOSs) improves performance and gut health of healthy 28-day old weaning piglets. Pigs received either a control basal (CON) diet, the CON diet containing 1% GOS for 7 days followed by the CON diet containing 0.017% XOS for 47 days (GXOS), or the CON diet for 7 days followed by the CON diet containing 0.017% XOS for 47 days (XOS). Body weight, average daily gain, average daily feed intake, and feed conversion ratio did not differ between diets from day 1 of weaning (d1) to d54. At d7, GXOS pigs showed increased jejunal and caecal α-diversity (Shannon, inverse Simpson), distinct ileal β-diversity (Yu and Clayton, Bray–Curtis, Jaccard), and greater short-chain fatty acid-producing Lactobacillus and Veillonella; no taxa remained differentially abundant by d22, and the XOS group showed no microbiota shifts throughout the study. Jejunal goblet cell density was lower in GXOS pigs at d7. Jejunal and caecal IL-1β, IL-6, IL-8, and IL-10 gene expression was transiently greater at d7 in GXOS pigs, whereas by d22 cytokine/chemokine differences resolved, whilst intestinal alkaline phosphatase was upregulated in the ileum and caecum (XOS) and colon (GXOS and XOS). Sequential prebiotic switching and delayed XOS onset likely missed the immediate post-weaning window, during which the gut microbiota is most receptive to dietary modulation, consequently limiting potential performance gains; therefore, prebiotic timing, sequence, and duration are critical to achieving functional benefits at weaning. Full article

Triclocarban (TCC), a synthetic antimicrobial compound prevalent in personal care products, has emerged as a typical contaminant in aquatic ecosystems. Intestinal microbiota maintains the host’s health homeostasis by regulating nutrient metabolism and immunity and is regarded as a sensitive biomarker for the risk assessment of pollutants. Currently, there is still a lack of toxicity assessment of TCC on the intestinal microbiota homeostasis of shrimp. Therefore, this study employed 16S rDNA sequencing to explore intestinal microbiota perturbations in Penaeus monodon following subchronic exposure (14 days) to graded TCC concentrations (1 and 10 μg/L). The results showed that TCC exposure altered intestinal microbiota diversity, marked by increases in the ACE, Chao1, and Shannon indices and a decrease in the Simpson index; however, none of these changes reached statistical significance (p > 0.05). Furthermore, the community composition was also altered, characterized by a significant increase in Bacteroidetes and a significant decrease in Tenericutes (p < 0.05), alongside non-significant increases in Proteobacteria and decreases in Firmicutes (p > 0.05). The abundances of some putative beneficial bacterial genera (Alloprevotella, Bacteroidales S24-7 group_norank, Cetobacterium, Enterococcus and Lactobacillus) and harmful bacteria (Photobacterium and Aeromonas) were decreased (p > 0.05); the abundance of Vibrio was decreased in the T1 group but increased in the T10 group (p > 0.05). Additionally, the predicted functions of the intestinal microbiota, such as glycan biosynthesis and degradation, steroid and isoflavone biosynthesis, and nucleotide metabolism, were enhanced. These results indicated that TCC exposure had a negative effect on the homeostasis of the intestinal microbiota of P. monodon. Full article

Corn–soybean strip intercropping (abbr. CSSI system) can enhance species biodiversity and ecological services for ecological control of insect pests. To improve its effectiveness and fully utilize it to improve ecological control of insect pests and crop production, two monoculture types of corn (C) and soybean (S), and two strip intercropping patterns (i.e., C3S3 and C3S4, indicating three rows of corn strip intercropped with three and four rows of soybeans respectively), were conducted to assess the CSSI system’s (i.e., C3S3 and C3S4) impacts on the abundance of insect pests and crop yields by a two-year field experiment. The results indicated that a total of 11 species of insect pests were found in the CSSI system. Compared with C or S monoculture, the community indexes of insect pests (including the Shannon–Wiener diversity index (H), the Pielou’s evenness index (E), and the Margalef’s richness index (D)) increased, and the Simpson’s dominance index (C) decreased in the C3S3 and C3S4 patterns in 2022. Compared to the C and S monoculture, the CSSI system decreased the population dynamics of total insect pests and the key insect pests Trialeurodes vaporariorum on corn and soybean plants, respectively. In the CSSI system, T. vaporariorum exhibited higher population dynamics on corn plants than on soybean plants, indicating a preference for corn plants under the CSSI system. Moreover, the corn yield per hectare in the C3S4 pattern was significantly higher than that of the C monoculture in 2022–2023. The biomass per plant and the 1000-grain weight of corn in the C3S3 pattern were significantly lower than that in the C monoculture and C3S4 pattern in 2022. The biomass per plant, the 1000-grain weight and yield per hectare of soybean in the C3S3 and C3S4 patterns were significantly lower than that in the S monoculture in 2022–2023. The land equivalent ratio (LER) was <1.0 in the CSSI system, posing yield loss risk for soybeans in the CSSI system. The competitive ratio (CR) of corn was greater than soybean in the CSSI system. In addition, the yield of corn and soybeans were not significantly correlated with the abundance of total insect pests, while the soybean yield was significantly positively correlated to the abundance of T. vaporariorum. In conclusion, it is presumed that the CSSI system can decrease the abundances of insect pests, particularly key insect pests, and maintain their community stability, thereby preventing insect pests’ outbreak. However, the CSSI system is disadvantageous for soybean yield, as it cannot fully utilize land resources and may pose a risk of system yield loss. Full article

Global biodiversity assessments have traditionally emphasized species richness; however, a comprehensive understanding of marine biodiversity patterns requires incorporating measures of evenness to capture differences in dominance and rarity among species. In this study, we evaluate the evenness in diversity globally of sea anemones (Actiniaria), a cosmopolitan group of understudied marine invertebrates. We assembled a dataset of 247,542 occurrence records from GBIF (Global Biodiversity Information Facility), converted them into incidence data, and estimated diversity at multiple spatial scales using rarefaction, extrapolation, and coverage-standardized Shannon and Simpson indices. We find the highest evenness-based diversity in areas where marine provinces and current systems converge, notably the Philippines, Chile, South Africa, the eastern United States, and Haida Gwaii, British Columbia. Regions with high evenness globally only overlapped with regions of greatest species richness globally in one case, Haida Gwaii. Integration of evenness-based metrics alongside species richness improves the comprehensiveness of biodiversity assessments and points to regions and species in need of further exploration. Full article

This study investigates landslide occurrence in Taiwan, a region highly susceptible to landslides due to steep mountains and frequent typhoons (TYPs). The primary objective is to understand how both geomorphological factors and TYP characteristics contribute to landslide occurrence, which is essential for improving hazard prediction and risk management. The research analyzed landslide events that occurred during the TYP seasons of 2019 and 2023. The methodology involved using satellite-derived landslide inventories from SPOT imagery for events larger than 0.1 hectares, tropical cyclone track and intensity data from IBTrACS v4 (classified by Saffir–Simpson Hurricane Scale), and detailed topographic variables (elevation, slope, aspect, Stream Power Index) extracted from a 30 m Shuttle Radar Topography Mission Digital Elevation Model (SRTM-DEM). Land use and land cover classifications were based on Landsat imagery. To establish a timeline, landslides were matched with TYPs within a ±3-day window, and proximity was analyzed using buffer zones ranging from 50 to 500 km around storm centers. Key findings revealed that landslide susceptibility results from a complex interplay of meteorological, topographic, and land cover factors. The critical controls identified include elevations above 2000 m, slope angles between 30 and 45 degrees, southeast- and south-facing aspects, and low Stream Power Index values typical of headwater and upper slope locations. Landslides were most frequent during Category 3 TYPs and were concentrated 300 to 350 km from storm centers, where optimal rainfall conditions for slope failures exist. Interestingly, despite the stronger storms in 2023, the number of landslides was higher in 2019. This emphasizes the importance of interannual variability and terrain preparedness. These findings support sustainable disaster risk reduction and climate-resilient development, aligning with Sustainable Development Goals 11 (Sustainable Cities and Communities) and 13 (Climate Action). Furthermore, they provide a foundation for improving hazard assessment and risk mitigation in Taiwan and similar mountainous, TYP-prone regions. Full article

Ziziphus lotus (L.) Lam., (Rhamnaceae) a resilient shrub native to Moroccan’s arid regions, functions as a keystone species by creating microhabitats that buffer temperature extremes, retain soil moisture, and accumulate organic matter. However, its role in structuring soil fungal diversity and community composition in these environments remains largely unexplored. This study investigated the spatial distribution of fungal communities associated with Z. lotus in barley-planted and non-planted fields. Soil samples were collected at 0, 3, and 6 m from shrub clusters during the barley harvest. The fungal community was dominated by Ascomycota (93.5%). Alpha diversity indices (Shannon–Wiener and Simpson) were significantly higher near shrub bases (0 and 3 m) compared to more distant soils (6 m), indicating a clear decline in diversity with distance (0 m vs. 6 m: p = 0.0012; 3 m vs. 6 m: p = 0.0007). Soil physicochemical parameters, including calcium carbonate content, nitrate, and salinity, significantly influenced fungal diversity (p ≤ 0.05). Beta diversity analysis revealed significant spatial differentiation in fungal community composition (PERMANOVA: p = 0.001). Overall, fungal richness and diversity were highest near shrub. Genera such as Cladosporium, Fusarium, and Alternaria were more abundant near shrub bases, while taxa like Didymellaceae and Alfaria were specially restricted. Functional predictions indicated dominance of fungi with mixed trophic modes (pathotroph–saprotroph–symbiotroph), suggesting ecological plasticity. Despite barley cultivation, the fungal community structure remained largely similar between the planted and non-planted fields. Overall, our findings underscore the ecological importance of Z. lotus as a reservoir of stress-tolerant fungi and as a potential keystone species for restoring degraded arid ecosystems. Full article

This study explores the effects of afforestation in infertile mountainous areas on soil microbial communities and functional nutrient cycling genes in young Cyclobalanopsis gilva forests, aiming to provide a scientific basis for promoting C. gilva growth. Employing metagenomic sequencing coupled with integrative analyses of microbial community structure and functional genes, this study took 7-year-old C. gilva forest stands in infertile mountainous areas of Shouchang Forest Farm, Zhejiang Province as the research object, using adjacent 7-year-old C. gilva forest in woodland areas as a control, to analyze the differences in soil microbial community structure and nutrient cycling functional genes in the rhizosphere (SCG) and non-rhizosphere (SNR) of infertile mountainous areas, as well as from the rhizosphere (FCG) and non-rhizosphere (FNR) of control woodland areas, and further explore their relationships with the growth of C. gilva. The results indicated that the contents of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and microbial biomass nitrogen (MBN) in SNR were significantly lower than those in FNR by 59.50%, 39.57%, 29.32%, and 53.13%, respectively. Bradyrhizobium and Trebonia were the dominant genera in both site conditions; however, the relative abundance of these genera was lower in infertile mountainous areas compared to the control. Notably, the Shannon and Simpson indices of SCG were significantly lower by 0.49 and 0.01 than those of SNR (p < 0.05), respectively. Additionally, the relative abundances of carbon fixation and nitrogen fixation of SCG were significantly higher than those of SNR. And the relative abundances of functional genes involved in carbon cycling (glyA, fdhA), nitrogen cycling (nasA, narfC, narC, and nirB), and phosphorus cycling (phoB) in infertile mountainous areas were significantly higher than those in the control. The nutrient cycling processes and the expression of functional genes in SCG are coordinately regulated by soil nutrients (SOC and TN) and microbial biomass [MBC (microbial biomass carbon) and MBN]. This work provides a mechanistic foundation for optimizing afforestation strategies and ecological restoration in nutrient-limited mountainous ecosystems, highlighting the critical role of microbial functional plasticity in overcoming edaphic constraints. Full article