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• Derleme MakaleAçık Erişim2026/r/gumushane/16347
  Nanoplastic Translocation Across Biological Barriers (Blood-Brain, Placental, Intestinal): Transport Mechanisms, Tissue-Specific Vulnerabilities, and a Corona-Driven Barrier Selectivity Framework

  Berber, Ahmet Ali; Yildiz, Esra; Berber, Nurcan; Kurnaz, Muammer; Kenanoglu, Nihan Akinci

  Nanoplastics (NPs; <= 1 & micro;m) have been detected in human placenta, blood, lung, atherosclerotic plaque, testis, semen, olfactory bulb, and brain, shifting the field from environmental description toward mechanistic interrogation of barrier crossing. This review synthesises current evidence on NP translocation across the intestinal epithelium, the blood-brain barrier (BBB) and the placental syncytiotrophoblast. We distinguish four evidence categories throughout the review: detection, association, mechanism, and causality. We also apply model-system labels (in silico, in vitro, ex vivo, animal, and human) to every mechanistic claim, so that the strength of each statement can be read off directly. Most current studies use pristine polystyrene nanoplastics at concentrations 3-6 orders of magnitude above plausible human exposure, so the mechanistic conclusions below are hypothesis-generating for human disease rather than definitive. We propose a working conceptual framework-corona-driven barrier selectivity (CDBS)-in which the particle-corona-surface complex, rather than the bare polymer, is hypothesised to dictate which receptor and transport machinery (TfR1, LRP1, FcRn, P-gp/BCRP, caveolae) each barrier engages. CDBS is offered as a hypothesis-stage organising tool requiring experimental validation, not as an established mechanism. We outline reported transport modes, including clathrin- and caveolin-mediated endocytosis, paracellular leakage via ROS-induced tight-junction disassembly, receptor-mediated transcytosis, and the candidate olfactory route. We emphasise that pristine polystyrene-bead doses commonly exceed plausible human exposure by 3-6 orders of magnitude, that detection methods underestimate sub-micrometre particles, and that causal links between NPs and human disease remain hypothesis-generating. A research agenda built on weathered reference materials, microphysiological systems, and integrative human biomarker science is proposed.

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• Derleme MakaleAçık Erişim2026/r/gumushane/16327
  Microplastic Contamination in Amphibians and Reptiles: An Ecotoxicological Synthesis of Exposure, Mechanisms, and Risk Implications

  Berber, Ahmet Ali; Akbulut, Cansu; Demir, Sefika Nur; Kurnaz, Muammer

  Microplastic (MP) contamination has become a defining feature of twenty-first century environmental change, yet the toxicological and ecological consequences for amphibians and reptiles-two vertebrate classes already facing severe extinction pressures-remain fragmented across taxa, regions, and methodological traditions. Here, we synthesize field and experimental evidence from five continents to provide a taxonomically balanced, mechanistically grounded, and geographically explicit assessment of MP exposure, bioaccumulation, and toxicity in herpetofauna, drawing on a structured literature search in Web of Science, Scopus, and PubMed (January 2015-March 2026). Field detection rates of MPs in amphibian larvae range from 26% in conservatively screened Central European populations to 73-80% in anuran tadpoles from high-anthropogenic-pressure Anatolian catchments, with fibrous polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) particles dominating the detected burden. Mechanistic evidence converges on oxidative stress cascades, hypothalamic-pituitary-thyroid axis disruption, gut and cutaneous microbiome dysbiosis, and compromised antiviral and antifungal immunity, with the latter potentially amplifying vulnerability to Batrachochytrium dendrobatidis and to ranavirus. Among reptiles, sea turtles display near-universal MP ingestion with documented maternal transfer to eggs; freshwater turtles, terrestrial squamates, and crocodilians remain critically understudied. Three structural asymmetries constrain current ecotoxicological risk characterization: taxonomic bias toward anurans and sea turtles, geographic bias toward the Global North, and experimental bias toward acute, supra-environmental laboratory exposures using pristine, single-polymer particles that fail to capture the chemical complexity of weathered field mixtures. We argue that MP burden may warrant consideration as a candidate stressor criterion within IUCN Red List assessments and within environmental risk assessment frameworks for freshwater and terrestrial biodiversity once a robust quantitative relationship between MP burden and demographic decline or population-level fitness has been established, and propose six hypothesis-driven research priorities: methodological standardization, reptile toxicokinetics, transgenerational epigenetics, MP-pathogen microbiome interactions and their translation into population viability models, temperature & times; MP interaction under climate warming, and population-genetic consequences of contemporary MP-driven selection, as the most tractable avenues for ecotoxicological progress and for the development of herpetofauna-specific risk characterization frameworks.

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• Derleme MakaleYalnız künye2026/r/gumushane/13858
  Marine microsporidia: Hidden diversity, aquatic emergence and zoonotic risks

  Bekircan, Çağrı; Kurnaz, Muammer

  Marine Microsporidia represent an increasingly important but historically underestimated group of aquatic intracellular parasites. Although traditionally associated with invertebrates and fishes, recent molecular and environmental studies have revealed extensive hidden diversity across marine ecosystems together with unexpected phylogenetic links between aquatic and human-associated lineages. This review synthesizes five decades of research (1975–2025) concerning the biology, evolution, taxonomy, host–pathogen interactions, ecological diversity, and zoonotic significance of marine Microsporidia. Particular emphasis is placed on members of the Enterocytozoonidae, including Enterocytozoon hepatopenaei, Nucleospora spp., and Desmozoon lepeophtherii, which represent major threats to aquaculture sustainability and may contribute to cross-environmental transmission pathways. Environmental DNA studies further indicate that marine microsporidian diversity is substantially underestimated by morphology-based approaches. However, current evidence for zoonotic transmission remains largely indirect, resting chiefly on phylogenetic relatedness, shared genotypes across hosts and environmental (eDNA) detection; direct, seafood-borne human infection has not yet been demonstrated. Current evidence suggests that aquaculture intensification, climate-driven environmental change, and expanding seafood trade may facilitate the emergence and dissemination of zoonotic microsporidian lineages. Integrating marine Microsporidia into One Health surveillance frameworks is therefore increasingly important for both ecosystem and public health management.

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• Derleme MakaleAçık Erişim2026/r/gumushane/13820
  Quaternary palaeoenvironmental archives of the Indian subcontinent and their imprint on herpetofaunal biogeography: A multi-proxy synthesis

  Kurnaz, Muammer

  This review presents the first integrated proxy, mechanism and biotic-response framework for the Indian Quaternary, linking the Subcontinent's dense network of palaeoenvironmental archives to the biogeographic trajectory of its endemic herpetofauna. Speleothem δ18O records, Arabian Sea and Bay of Bengal sediment cores, Karewa and peninsular lake sequences, Siwalik and Narmada alluvium, and Kurnool cave deposits together document Indian Summer Monsoon (ISM) variability on orbital, millennial, centennial and historical timescales (the historical band here denoting the past ∼2000 years, resolved by dated speleothem and documentary records). Against this proxy backbone, the fossil and molecular phylogeographic record of Indian amphibians and reptiles is evaluated as a biogenic assemblage here, the body of biological evidence (fossils, subfossils and the phylogeographic signatures of living taxa) that, like pollen or foraminifera, records past environmental conditions that complements geological and climatological archives. Three patterns emerge. At orbital scale, ISM variability aligns with Plio–Pleistocene diversification slowdowns in Western Ghats ranoids and with the Late Pliocene lineage divergence of the Himalayan toad Duttaphrynus himalayanus across the Thakkhola basin. Abrupt Holocene excursions, including the 8.2 ka and 4.2 ka events, are resolved at high precision in speleothem and marine archives but remain untested against coalescent demographic inference in Indian herpetofauna. Late Pleistocene aridity, most severe at the Last Glacial Maximum, coincides with community-level impoverishment in peninsular cave faunas at Kurnool, although the available evidence establishes co-occurrence rather than a demonstrated causal role for aridity relative to co-varying thermal and vegetation change. Three proxy-calibrated research priorities follow: microvertebrate taphonomy in Narmada and Karewa sequences, population genomics tied to speleothem chronology, and species-distribution hindcasting to the LGM, mid-Holocene and 4.2 ka intervals. The synthesis contributes to a biogenic assessment of Quaternary-to-Recent climate impacts on life on the Indian Subcontinent, aligned with UN Sustainable Development Goals 13 (Climate Action) and 15 (Life on Land), and supports future projections of amphibian and reptile response to ongoing change.

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• MakaleAçık Erişim2026/r/gumushane/13622
  Core–Periphery Organization and Spatial Heterogeneity in Pseudopus apodus (Anguidae) Across Its Western Palearctic Range

  Şahin, Mehmet Kürşat; Topal, Azra; Kurnaz, Muammer

  Understanding the internal spatial structure of widely distributed species is fundamental for biogeographic theory and conservation practice, yet such structure is often masked by extent-based range metrics. We investigated the spatial organisation of Pseudopus apodus (Pallas, 1775), the largest limbless lizard of the Western Palearctic, using 3967 occurrence records spanning 1843–2025. Spatial point pattern analysis revealed a pronounced deviation from complete spatial randomness (Clark–Evans R = 0.105, p < 0.001), with strong fine-scale clustering. Kernel density estimation identified a clear core–periphery organisation: high-density core areas accounted for 30% of records but occupied only 22% of the total extent of occurrence (EOO). The discrepancy between EOO (~8.9 million km2) and area of occupancy (AOO; ~8944 km2) spanned three orders of magnitude, emphasising that only a small fraction of the species’ geographic envelope is actively occupied. Spatial heterogeneity was high (coefficient of variation ≈ 0.99), and core and peripheral occurrences were significantly segregated along both latitudinal and longitudinal gradients. The proportion of core records showed a weak positive temporal trend most plausibly attributable to sampling effort, particularly the recent expansion of citizen-science contributions, rather than to ecological processes. These findings demonstrate that P. apodus exhibits a compact spatial core embedded within a broad, sparsely occupied periphery, underscoring the limitations of EOO-based metrics in the conservation assessment of widely distributed reptiles. We emphasise that this structure is characterised using the density of occurrence records and therefore describes the observed spatial organisation of the available data rather than directly measured population density; ecological interpretations are accordingly framed as hypotheses requiring independent validation.

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• MakaleYalnız künye2026/r/gumushane/13605
  Spatial heterogeneity of microscopically detected Nosema spp. infection in honeybees: Climate-associated patterns in the Eastern Black Sea Region of Türkiye

  Tosun, Onur; Bekircan, Çağrı; Kurnaz, Muammer

  Nosemosis has emerged as the predominant microsporidian infection of honeybees (Apis mellifera L.) in many regions, including Türkiye, yet the climatic drivers of its epidemiology remain insufficiently quantified. This study assessed the effects of temperature and relative humidity on nosemosis prevalence across seven provinces in the climatically diverse Eastern Black Sea region. A dataset of 2688 colony-level observations was analyzed using generalized linear models, mixed-effects models, beta regression, generalized additive models, and spatial autocorrelation. Both temperature and humidity were consistently significant predictors (p < .001). Quadratic temperature terms and nonlinear GAM smooths were consistent with a thermal performance pattern, with infection peaking at intermediate ranges. Humidity exerted threshold-like effects, with disproportionately higher prevalence at upper quantiles. Province-level random effects accounted for ∼18% of variance, underscoring spatial heterogeneity, while elevation was not significant once climatic variables were included. Exploratory spatial analysis (Global Moran's I = −0.476, p = 0.043) tentatively suggested dispersion rather than clustering; however, given the very small number of spatial units (n = 7), this result should be regarded as hypothesis-generating only. The beta mixed-effects model achieved moderate predictive accuracy under cross-validation (RMSE ≈ 0.109). Collectively, these findings indicate that nosemosis prevalence in the region is strongly associated with climatic variability, exhibits nonlinear and threshold-like responses, and shows pronounced spatial heterogeneity. We emphasize that these are statistical associations and that unmeasured factors (e.g., colony strength, nutrition, pesticide exposure, management practices, and co-infections) likely contribute to the unexplained variance. By integrating hierarchical, nonlinear, and spatial approaches, this study establishes a climate-associated epidemiological assessment of nosemosis risk in A. mellifera and highlights the importance of localized climatic suitability under ongoing climate change.

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• Derleme MakaleAçık Erişim2026/r/gumushane/12322
  Physiological responses and adaptive mechanisms of amphibians and reptiles to multiple interacting environmental stressors: an integrative review

  Kurnaz, Muammer

  This integrative review synthesizes current knowledge on the physiological responses and adaptive mechanisms of amphibians and reptiles to multiple interacting environmental stressors, with particular emphasis on synergistic effects among temperature, hydric stress, disease, and pollution. Given the stronger empirical basis for amphibians in the existing literature, amphibian responses are covered in greater depth, while reptile-specific physiology, immunology, and emerging infectious diseases are explicitly addressed in dedicated sections throughout the review. Critical thermal tolerance analyses reveal that approximately 7.5% of amphibian species will exceed their physiological limits under a 4 °C warming scenario, with tropical lowland species already operating near their CTmax thresholds. Thermal plasticity is limited, with acclimation responses averaging only 0.13 °C increase in CTmax per 1 °C environmental warming—insufficient to track rapid climate change. Water balance regulation shows dramatic interspecific variation, with cutaneous resistance ranging from 0.05 s/cm in aquatic amphibians to >1000 s/cm in desert-adapted reptiles. Synergistic interactions between thermal and hydric stress significantly amplify vulnerability, particularly in dehydration scenarios that reduce critical thermal limits. Chemical pollutants, including heavy metals and pesticides, cause developmental abnormalities (535% increase in malformation frequency), immunosuppression, and endocrine disruption across multiple life stages. Emerging infectious diseases, particularly chytridiomycosis (Batrachochytrium dendrobatidis and B. salamandrivorans) and ranaviruses, drive mass mortality events globally, with co-infections exacerbating population declines. Climate change intensifies disease susceptibility through stress-mediated immunosuppression and altered pathogen dynamics. Adaptive capacity varies markedly among species. While amphibians exhibit strong phenological responses (2-4× greater than other taxa), genetic adaptation potential remains limited by narrow dispersal abilities and habitat fragmentation. Microhabitat buffering can reduce thermal extremes by several degrees but depends critically on habitat structural integrity. This review demonstrates that the pace of anthropogenic change challenges the adaptive capacity of most species, necessitating integrated conservation strategies including microhabitat preservation, climate corridor establishment, pollution mitigation, disease surveillance, and ex-situ conservation programs.

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• MakaleYayıncıda açık erişim2026/r/gumushane/12250
  Blinking without eyelids: first video-documented evidence of a blink-like reflex in Ophisops elegans (Reptilia: Lacertidae)

  Çelebi, Turan Meriç; Çelikağı, Yusuf; Kınay, Tuana; Kuyucu, Arda Cem; Kurnaz, Muammer; Şahin, Mehmet Kürşat

  Eyelids play a crucial role in protecting the eyes of vertebrates; however, certain reptile species, such as Ophisops elegans, completely lack movable eyelids. In this study, we present the first video-documented evidence of a blink-like reflex in O. elegans, captured through endoscopic field observations and corroborated by laboratory video analysis. The observed movement consisted of a brief convex deformation of the ocular surface, lasting approximately 0.3 s and resembling a blink despite the presence of a fixed transparent brille. This behavior was observed once in the field and twice under controlled laboratory conditions. We propose that O. elegans may employ subtle contractions of the ocular musculature to mimic the protective function of blinking. These findings indicate a novel compensatory mechanism in eyelidless lizards and underscore the need for further research into ocular adaptations among reptiles.

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• MakaleAçık Erişim2026/r/gumushane/12167
  Citizen-Science Data Reveal Global Diversity Patterns in the Gecko Genus Hemidactylus

  Kurnaz, Muammer; Berber, Ahmet Ali; Akbulut, Cansu

  Understanding how species richness is distributed across space is a central goal of macroecology and biogeography. The gecko genus Hemidactylus ranks among the most speciose and broadly distributed of all squamate genera, with species spanning tropical and subtropical environments on most continents. Yet the large-scale structure of its diversity has rarely been examined at a global scale. Here we assembled georeferenced occurrence data for the genus from the Global Biodiversity Information Facility (GBIF Access data is 14 March 2026) and, following cleaning and quality control, retained 143,858 records covering 157 currently recognized species (approximately 79% of the genus) to characterize broad-scale biodiversity patterns. Our analyses addressed the latitudinal diversity gradient, the distribution of species range sizes, continental richness, spatial clustering of diversity, and regional beta diversity. Richness declined steadily from the tropics toward the poles, producing a pronounced latitudinal diversity gradient (Pearson r = −0.71, p < 0.001). A generalized additive model captured a strong non-linear association between latitude and richness (deviance explained = 98.1%), consistent with tropical regions acting as principal centers of diversity. Range-size distributions were markedly right-skewed, with the majority of species restricted to comparatively small areas; however, these estimates co-varied strongly with per-species sampling effort (r = 0.90) and warrant cautious interpretation. We found only a weak, marginally significant association between range size and latitudinal midpoint, offering little support for Rapoport’s rule in the genus. At the continental scale, Hemidactylus diversity was overwhelmingly concentrated in Afro-Asian tropical regions (Asia, 93 species; Africa, 66), whereas Europe and Oceania supported few species (four each). Spatial analyses indicated significant autocorrelation in richness (Moran’s I = 0.56, p < 0.001) and well-defined diversity hotspots in East Africa, the Indian subcontinent, and Southeast Asia, and regional beta diversity was high (Jaccard dissimilarity up to 0.97), reflecting pronounced faunal turnover among continents.

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• MakaleAçık Erişim2025/r/gumushane/19674
  Unusual Winter Activity of the Ottoman Viper (Montivipera xanthina) in Türkiye

  Sahin, Mehmet Kursat; Kurnaz, Muammer; Bayram, Çağatay

  The seasonal dynamics of reptile species and their responses to fluctuations in environmental temperature play a crucial role in their overall ecological functions. Reptiles are ectothermic organisms, meaning their activity levels are largely influenced by external temperatures. While most reptile species in temperate regions enter a state of hibernation during colder months, some exceptions may occur due to environmental changes. In this study, an unusual instance of winter activity was documented for Montivipera xanthina (Ottoman viper) in the Karalan-Eskişehir region of Turkey. A single individual was observed on November 2, 2024, at an ambient temperature of 18.6°C. This observation provides significant insights into the winter behaviors of reptiles, which are generally considered inactive during this period. A review of existing literature reveals no prior records of Montivipera xanthina exhibiting activity in November or any other winter months. Therefore, this study presents the first known documentation of winter activity in this species, raising questions about the potential effects of climate change on reptilian seasonal behaviors. Rising temperatures and shifting seasonal patterns may be altering the hibernation strategies of reptiles, leading to extended activity periods. Such changes could have ecological consequences, affecting predator-prey interactions, reproductive cycles, and overall species distributions.

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