Search Results (4,129)

Accurate modeling of the tooth friction coefficient is central to analyses of efficiency, vibration, and durability in enclosed gear drives. Physics-based models describe these contacts using a large set of coupled thermal, contact, and lubrication laws whose individual parameters have uncertainties that are difficult to propagate. This study proposes a compact alternative: the HAF model, a three-parameter phenomenological description of the friction coefficient as a function of the slide-to-roll ratio (SRR). The three parameters have distinct tribological interpretations: h (hysteresis) governs the steepness of the sigmoidal transition, a (attrition) governs the slope of the plateau, and ν (friction level) governs the overall magnitude. The model is calibrated using nonlinear regression with fourteen two-disc traction curves acquired with a one-factor-at-a-time (star) design around a reference operating point (1.6 GPa, 80 °C, and 20 m/s): the contact pressure (1.2, 1.6, and 1.9 GPa), the injection temperature (40, 80, and 100 °C), and the mean speed (10, 20, and 30 m/s) are each varied in turn, for both smooth and rough discs. Parameter uncertainty is quantified using the residual-resampling bootstrap (BIG) established in a companion paper and applied over 10⁵ iterations; it yields near-Gaussian, weakly correlated parameter distributions. The three HAF parameters are then expressed as linear functions of load, temperature, speed, and roughness; least-squares inference across the fourteen conditions shows that eleven of the fifteen regression coefficients differ significantly from zero at the 5% level, with roughness having the strongest effect on the friction level (t = 7.98). Substituting these laws into the HAF equation and reoptimizing the resulting expression globally yields a single closed-form model that reproduces the measured friction coefficient with a residual spread of σ ≈ 0.001 in friction-coefficient units (R² ≈ 0.996) and approximately Gaussian, zero-mean, and homoscedastic residuals with no evident systematic structure. Being differentiable and equipped with bootstrap confidence intervals, the model predicts friction throughout the tested operating envelope—across which the maximum friction coefficient varies by a factor of eight, from 0.0049 to 0.0388—and supports gradient-based optimization of low-friction operating conditions. The contribution of this study is a compact, interpretable, and statistically characterized predictive law for tooth friction, expressed in closed form as a function of the operating conditions and of the surface state. Full article

Background: Low back pain (LBP) remains the leading global cause of years lived with disability, and image-guided nerve blocks occupy a central position in its diagnostic and therapeutic pathway. Two paraspinal targets separated by only a few centimetres of tissue address entirely different neural territories: the medial branch of the lumbar dorsal ramus, addressed by the medial branch block (MBB), and the ventral rami of L1–L4 that form the lumbar plexus within psoas major, addressed by the psoas compartment block (PCB). Despite this anatomical proximity, the two techniques have matured within largely separate literatures—interventional pain medicine for the MBB and regional anaesthesia for the PCB—and have never been compared head-to-head in a randomised trial. Methods: This narrative review searched PubMed/MEDLINE, Embase, Scopus, the Cochrane Library, and Google Scholar to 1 August 2026 and synthesises evidence on the anatomical rationale, technical performance, effectiveness, and safety of both blocks as they apply to patients presenting with LBP. Results: The MBB is supported by extensive diagnostic-accuracy data and guideline endorsement for facet-mediated axial pain, but requires controlled blocks to constrain false-positive rates and confers only short-lived therapeutic benefit. The PCB reliably produces dense lumbar plexus analgesia and has a well-defined perioperative role, yet direct evidence in chronic LBP is confined to small series, and its complication profile—including epidural spread and retroperitoneal haematoma—is materially more demanding. Conclusions: We propose a phenotype-driven selection framework in which the MBB serves posterior-element axial pain while the PCB is reserved for plexus-mediated, hip–spine overlap, and perioperative indications, and we outline the comparative studies required to test it. Full article

Respiratory allergies are among the most prevalent chronic diseases worldwide, and seasonal allergic rhinitis and asthma place a substantial burden on patients and healthcare systems. Pollen from trees, grasses, and weeds contribute to a wide spectrum of clinical manifestations, while globalization, urban landscaping, biological invasions, and climate change are facilitating the spread of new allergenic plants across continents. Ailanthus altissima (tree of heaven) is a fast-growing deciduous tree native to China that has become widely distributed in North America and Europe, including Romania. Although initially introduced as an ornamental and shade tree, its rapid growth, tolerance of pollution and drought, and ability to colonize disturbed urban habitats have increased its relevance as a potential aeroallergen. This narrative clinical review synthesizes evidence from clinical case reports, sensitization studies, molecular allergen characterization, aerobiological monitoring, and Romanian distribution data. To improve clinical and public health applicability, the review includes summary tables comparing Ailanthus with other emerging allergens such as ragweed and Platanus, outlining Romanian ecological and pollen-monitoring evidence, summarizing diagnostic implications for ENT and allergy practice, identifying evidence gaps, and presenting future research priorities. Current evidence supports A. altissima pollen as an emerging but under-recognized respiratory allergen, particularly in urban areas where the tree is established. However, major limitations remain, including the lack of standardized diagnostic extracts, incomplete molecular allergen validation, limited routine pollen monitoring, and absence of Romanian clinical sensitization studies. Greater clinical awareness, species-specific aerobiological surveillance, standardized allergen characterization, and coordinated Romanian sensitization studies are needed to determine the extent to which A. altissima pollen contributes to allergic rhinitis and asthma. Future research should explicitly distinguish species occurrence, airborne pollen exposure, IgE sensitization, and clinically relevant respiratory disease when evaluating the emerging allergenic importance of A. altissima. Full article

This paper develops a stochastic susceptible–infected–hesitating–removed (SIHR) rumor model with Hill-type saturated incidence and compartment-specific Brownian perturbations. The model focuses on when environmental noise changes a rumor’s deterministic fate and how long-run behavior is organized as an invariant law rather than a fixed level. The hesitating class is interpreted as a post-spreading verification state: users have already engaged with the rumor but temporarily suspend further forwarding before removal. A corrected stochastic local reproduction number is derived from the logarithmic growth rate of the linearized spreader equation along the stochastic rumor-free boundary. Its Itô correction includes the second moment of the susceptible boundary process and therefore depends on the common attrition noise. Global existence and positivity are established from linear-growth and positive-invariance arguments, and the deterministic skeleton is shown to be well-posed, positive, bounded, and globally attracted to the endemic equilibrium when ${\mathcal{R}}_0>1$. Under explicit dissipativity and comparison assumptions, a Foster–Lyapunov argument with the full diffusion covariance matrix yields positive Harris recurrence, a unique invariant probability measure, and an ergodic time-average theorem. A media-debunking control problem is formulated through the stochastic maximum principle, while the implemented numerical schedule is stated as a drift-level open-loop approximation and then evaluated under the full stochastic dynamics. Numerical experiments, including 95% confidence bands, strong-saturation tests, stationary-density diagnostics, sensitivity surfaces, and control comparisons, support the revised threshold, recurrence, and intervention interpretations. Full article

Extensive clinical studies have convincingly demonstrated that fungal infections constitute a mounting global health concern. Candida albicans, C. auris, Aspergillus fumigatus, and Cryptococcus neoformans were classified by the WHO as critical priority fungi due to their widespread prevalence, high mortality rates associated with invasive mycoses, and the increasing spread of resistant strains. The currently available antifungal arsenal, comprising four major classes (azoles, polyenes, echinocandins, and flucytosine), is critically insufficient. Resistance to these agents is escalating worldwide, while the approval of new drugs remains alarmingly slow. This review provides a comprehensive overview of the molecular mechanisms underlying resistance to conventional and emerging antimycotics in critical priority fungi, including recently approved and investigational agents such as oteseconazole, rezafungin, ibrexafungerp, fosmanogepix, and olorofim. It examines current strategies to overcome resistance, including combination therapy, drug repurposing, targeted delivery, antibiofilm approaches, immunotherapy, and the application of natural antifungal compounds. Special emphasis is placed on antifungal peptides (AFPs) derived from plants, animals, bacteria, and fungi, along with their synthetic analogs, all of which have demonstrated efficacy against critical priority fungi. The review primarily focuses on the molecular targets of AFPs and on the development of fungal resistance under prolonged exposure, compared with conventional antifungals, in order to evaluate their potential as prototypes for next-generation antimycotics. Full article

Antimicrobial resistance is a growing global crisis that threatens to return humanity to a pre-antibiotic era where common infections become deadly. This narrative review synthesizes evidence from 2000 to early 2026, including Global Research on Antimicrobial Resistance data and World Health Organization surveillance, to outline the problem’s scale, drivers, and solutions. In 2019, bacterial resistance directly caused 1.27 million deaths and was linked to 4.95 million more. Low- and middle-income countries bear the heaviest burden. ESKAPE pathogens, especially carbapenem-resistant Acinetobacter baumannii and NDM-producing Klebsiella pneumoniae, drive intensive care unit mortality near 50% and cause untreatable neonatal sepsis. One Health drivers include antibiotic overuse in humans, with 30% of prescriptions unnecessary in high-income settings; agriculture, consuming 70% of global antibiotics; and environmental pollution, with resistance genes found in 72% of rivers. Bacteria spread resistance through horizontal gene transfer and mutations such as gyrA S83L, creating pan-drug-resistant strains that make surgeries, transplants, and cancer treatment risky. Economic modeling studies suggest that unchecked antimicrobial resistance could reduce annual global GDP by 1.1–3.8%, with some scenarios projecting losses of up to approximately 5% by 2050, depending on assumptions about healthcare costs, labor productivity, and livestock production. Solutions require subscription-based payment models, enforceable agricultural regulations, integrated genomic surveillance, and equity-focused diagnostics for low- and middle-income countries. Without binding 2030 targets, the post-antibiotic era would become a clinical reality within a decade. Full article

Antimicrobial resistance (AMR) has emerged as a critical global health concern that transcends human, animal, and environmental boundaries. The extensive and often indiscriminate use of antibiotics for disease control and growth promotion has accelerated the evolution and spread of resistant pathogens within the aquaculture sector. This review examines aquaculture-associated AMR through a One Health framework. We explore the molecular mechanisms of resistance such as efflux pumps, enzymatic degradation, mobile genetic elements, and horizontal gene transfer that drive the dissemination of antimicrobial resistance genes among aquatic microorganisms. The review synthesizes evidence linking AMR in aquaculture to public health impacts, including the transmission of resistant bacteria through seafood and environmental exposure. Current regulatory measures and stewardship policies are assessed to identify gaps in implementation, particularly in developing regions where enforcement and public awareness remain limited. Review highlights emerging alternatives such as bacteriophage therapy, engineered probiotics, synthetic microbial communities, and CRISPR-based systems as sustainable approaches to reduce antibiotic dependence. Future research priorities include the integration of genomics, artificial intelligence, and environmental DNA monitoring for precision surveillance. This review emphasis the need for cross-sectoral collaboration, innovation, and global policy coherence to mitigate AMR in aquaculture and safeguard food, environmental, and public health security. Full article

Lumpy skin disease (LSD) is a rapidly spreading viral disease of cattle that threatens livestock productivity and agricultural trade across Africa, the Middle East, and Asia. Despite effective vaccines being available, evidence-based guidance on allocating limited veterinary budgets across competing interventions remains lacking, and no LSD study has yet combined dynamic transmission modelling with a hard budget constraint and formal cost-effectiveness analysis. We develop a deterministic $S_h{V}_h{E}_h{I}_h{R}_h$–$S_v{I}_v$ (SVEIRSI) compartmental model for LSD, embedded within a budget-constrained optimal control framework with three time-dependent controls—vaccination ($u_1$), vector control ($u_2$), and movement restriction ($u_3$)—evaluated across all eight strategy combinations. The basic reproduction number is ${\mathcal{R}}_0=2.7899$. Pontryagin’s Maximum Principle characterises the optimality conditions. The resulting two-point boundary value problem is solved via forward–backward sweep with budget bisection over a 180-day horizon at three budget levels (${\mathcal{W}}_L=\mathrm{NAD}5000$, ${\mathcal{W}}_M=\mathrm{NAD}\mathrm{15,000}$, ${\mathcal{W}}_H=\mathrm{NAD}\mathrm{40,000}$). Vaccination dominates the optimal allocation at every budget, reducing peak infectious prevalence by 54–57% and averting 15,645–17,970 animal-days of cumulative burden relative to the uncontrolled baseline (${\mathcal{I}}_0=\mathrm{97,313}$ animal-days). Shadow-price analysis reveals that the budget constraint is non-binding across all three policy budget levels (actual optimal spend ≈ NAD 572), indicating that logistical (rather than financial) barriers are the true bottleneck, with the shadow price dropping to zero at $\mathcal{W}\approx \mathrm{NAD}1862$. Incremental cost-effectiveness analysis places vaccination alone ($S_1$), vaccination plus vector control ($S_{12}$), and the combined strategy ($S_{123}$) on the efficiency frontier, with ICERs of NAD 0.012, 0.015, and 0.166 per animal-day averted, respectively. One-way sensitivity analysis identifies vaccine efficacy $\epsilon$ as the dominant driver of cases averted (swing $\approx \mathrm{85,601}$ animal-days), while global sensitivity analysis via Latin Hypercube Sampling identifies the midge biting rate a as the strongest driver of cumulative infectious burden ($\mathrm{PRCC}=0.926$, $p<0.001$). These results provide actionable, quantitative guidance for LSD outbreak response in Namibia and comparable resource-limited settings. Full article

Attrition models are tuned for discrimination, but the decision they support is a ranking of retention drivers, and nothing requires that ranking to survive retraining. We treat its reproducibility as an objective: hyperparameter optimization for an ensemble of gradient-boosted and bagged learners becomes a bi-objective program maximizing the cost-sensitive area under the precision–recall curve jointly with the expected agreement of SHapley Additive exPlanations (SHAP) global rankings across bootstrap refits. Four results follow, three specializing standard theory. Hoeffding’s U-statistic theory makes the estimator unbiased with variance $4{\zeta }_1/R+O\left(R^{-2}\right)$, turning “how many refits” into a variance calculation; an elementary spacing argument makes a ranking’s survival a signal-to-noise rather than a noise-magnitude quantity; SHAP linearity makes the retraining variance in the ensemble attributions a quadratic form, so the mixing weights solve a minimum-variance portfolio. The fourth delimits the third: a ranking is invariant to attribution scale, and this variance is not, so attribution variance is no proxy for explanation stability—minimizing it selects the least stable learner on every benchmark—and stability is optimized directly. The cost of the scheme is given in closed form. Our central empirical finding is a caution. Across five public benchmarks spanning $1.4$–$50.6\%$ positives, no test separates the multi-objective solvers from the single-objective ones at a practitioner’s budget, and the objective must be estimated to be optimized: at the refit budget such a search would choose, the estimator’s standard deviation exceeds the spread of true stability across the configurations it ranks, so maximizing the estimate overfits it. Re-estimating each search’s own selection with draws that took no part in selecting it leaves a resolvable stability gain on two of the five benchmarks. Giving the search five and $12.5$ times the budget surfaces gains that survive where the practitioner’s budget surfaces none, so part of what a cheap search misses is real; but the gap between what a search advertises and what survives does not close as the budget grows, and on one benchmark widens. Declaring the objective is worth doing; what it pays cannot be read off the search that declared it. The caution applies to any model selection that resamples to estimate its criterion and then maximizes it. Full article

Background/Objectives: The Mediterranean Sea is highly susceptible to marine bioinvasions, with non-indigenous ascidians frequently introduced and dispersed via maritime traffic. Here, we report the first records of the non-indigenous ascidian Polyclinum constellatum Savigny, 1816 in Maltese waters, identified within Marsaxlokk Harbour, which hosts a major international transshipment hub in the Central Mediterranean. Situated at a crossroads of global shipping lanes, Malta serves as a critical geographic sentinel for monitoring the occurrence and spread of non-indigenous species within the basin. Methods: Two colonies of P. constellatum were collected in 2022 and 2023 respectively. Given the condition of the sampled colonies, the high morphological plasticity and cryptic diversity within the genus Polyclinum Savigny, 1816, species identification was established using molecular taxonomy through DNA barcoding against reference sequences. Results: The obtained sequences from the two colonies were identical and confirmed the species’ identity through a 100% match in GenBank and BOLD. Comparative analysis revealed that the 678 bp sequences obtained here differed by 1 bp from previously documented Mediterranean records while matching others from more distant locations. The structure of the haplotype network based on the homologous sequences, together with the occurrence of multiple mitochondrial haplotypes across the Mediterranean Sea that are shared with geographically distant regions rather than neighbouring Mediterranean localities, supports a scenario involving multiple introductions of P. constellatum into the region, likely associated with maritime transport. Conclusions: These findings highlight the importance of integrating genetic markers into biosecurity monitoring frameworks to resolve taxonomic identities of cryptic taxa, improve understanding of invasion pathways and assess genetic diversity associated with the establishment and spread of non-indigenous species in novel environments. Full article

Background: This study examined training-to-match transferability of positional coordination in semi-professional football players, comparing responses between defensive and midfield/offensive positional sectors. Methods: Twenty-nine players were monitored during the 2023–2024 season. Positional data and external load were collected using global positioning system (GPS) technology. Technical–tactical key performance indicators (KPI) were obtained from SportsBase. Internal training load was assessed using the rating of perceived exertion (RPE), and wellness status was evaluated using the Hooper Index (HI). Results: Official matches were associated with greater total distance, average and maximum speed, speed events, acceleration and deceleration events, and mechanical power outputs (p < 0.001), with the largest effects for maximum speed (d = 1.25), deceleration events (d = 1.14), speed events (d = 1.13), and relative mechanical power (d = 1.05). Positional responses showed distinct training-to-match patterns. In the defensive sector, the official matches showed higher spread rate (SR; p = 0.031, d = −1.83) and contraction time (CT; p = 0.007, d = −2.20). In the midfield/offensive sector, matches showed greater effective playing space, width, length, longitudinal synchronization, distance to sector centroid, and stretch index (p = 0.005–0.017; d = 1.73–2.61), whereas dyadic-distance variability was greater during training (p < 0.001, d = 4.46). Linear mixed-effects models confirmed greater locomotor and high-intensity demands during matches, while positional differences were more selective. No statistically robust tactical-sector differences were observed for KPIs, internal load, or wellness after adjustment for multiple comparisons. Conclusions: Training-to-match transferability was positional sector-dependent, with greater spatial expansion and longitudinal coordination in offensive players and higher overall locomotor demands during matches. Full article

The rapid spread of deepfake content poses a significant threat to the credibility of digital multimedia, creating an urgent need for accurate and robust detection methods. This paper proposes a hybrid deep learning framework that combines EfficientNet-B0 and Vision Transformer (ViT-B/16) through feature concatenation to exploit both local spatial representations and global contextual dependencies for image-level deepfake detection. The proposed model was trained and evaluated on the deepfake and real images dataset. Experimental results demonstrate that the proposed framework achieves an accuracy of 0.9870, an F1-score of 0.9871, and an AUC of 0.9990. Additional cross-dataset evaluation on the CelebDF-v2 image dataset and robustness experiments under common image degradations further demonstrates the strong generalization capability and practical applicability of the proposed approach. These results confirm that integrating CNN-based and Transformer-based feature extraction provides an effective and reliable solution for deepfake image detection. Full article

Various antiviral drug therapies have been developed for the treatment of coronaviruses, particularly SARS-CoV-2. However, the emergence of drug-resistant mutations is detrimental to clinical efficacy and global public health. Antiviral usage exerts selective pressures on viruses that manufacture an environment for resistant strains to emerge, in some cases at a fitness cost. However, the appearance of a compensatory mutation can restore or improve viral fitness, allowing the strain to persist and spread in a population. Here we evaluate the drug resistance mechanisms of multiple SARS-CoV-2 non-structural proteins, including the main protease (Mpro) and the RNA-dependent RNA polymerase (RdRP), which drive polyprotein processing and viral RNA replication, as well as PLPro, EndoU, and Mac1, which contribute to viral replication and counter host innate immune responses. We also discuss several methods that could be used to avoid drug resistance in the future. By integrating the understanding of molecular mechanisms of antiviral treatment with surveillance of resistance-associated mutations and new drug therapies, appropriate clinical approaches can be developed to reduce the impact of drug resistance. Full article

Vector-borne plant pathogens exhibit a remarkable capacity to colonize distantly related hosts, reflecting long-term ecological and evolutionary interactions among pathogens, plants, and insect vectors. Phytoplasmas, which are obligate bacterial parasites transmitted by hemipteran insects, represent a model system for investigating how host–pathogen associations diversify across ecological and evolutionary timescales. Despite extensive knowledge of phytoplasma diversity and vector relationships, the historical processes shaping these associations remain poorly understood. Here, we investigated the eco-evolutionary dynamics of global phytoplasma–hemipteran associations using complementary cophylogenetic approaches that integrate phylogenetic relationships, divergence time estimates, and host association data. We tested the hypothesis that community assembly of phytoplasma–vector networks over the last ~300 million years has been driven by multiple processes, including host switching, lineage duplication, and cospeciation, with additional influences from environmental change and historical biogeography. Our analyses revealed limited evidence for cospeciation across the evolution of the associations. Instead, duplication, host switching, and lineage losses were the predominant processes shaping current associations, with more than 90 inferred incongruent links between phytoplasmas and their insect hosts. A significant cophylogenetic signal was detected only between Psyllidae and phytoplasma group 16SrX, suggesting a history of relative ecological stability or specialization following their concurrent emergence in the Late Cretaceous. Reconstruction of the origins of phytoplasma associations with particular families of insect vectors indicates that the common ancestor of modern Cicadellidae may have already acquired an association with phytoplasmas, but that associations with other vector families were acquired more recently. These findings indicate that phytoplasma–vector associations are largely dynamic and shaped by ecological opportunity rather than strict codiversification. Integrating evolutionary history with ecological interactions provides a framework to better understand the emergence, persistence, and potential future spread of vector-borne plant diseases. Full article

The global spread of multidrug-resistant bacteria, alongside the rising burden of oncological diseases, poses an increasing threat to human health and public healthcare systems worldwide. Substantial efforts are underway to discover new drugs and to reposition or repurpose existing ones. Recently, nifuroxazide introduced into clinical practice in the late 1960s has attracted considerable attention due to its antitumor potential. However, its poor absorption in the intestinal tract limits its applicability as a systemic antitumor agent, a limitation that can be addressed through chemical modification. In this study, we evaluated 11 nifuroxazide analogs featuring systematic modifications to both the five-membered ring (replacement of furan with thiophene) and the six-membered aromatic ring (variation in the position and nature of substituents). MTT cytotoxicity assays performed on HCT116 and HEK293 cell lines revealed that 5-nitrofurfurylidene hydrazide of 2-pyridinecarboxylic acid and 5-nitrothien-2-yl hydrazide of 2-pyridinecarboxylic acid exhibit selective toxicity toward tumor cells while showing significantly lower toxicity to non-tumor cells, indicating potential for further investigation in more complex biological models. Antimicrobial activity testing identified 5-nitrofurfurylidene hydrazide of 3-hydroxybenzoic acid and 5-nitrofurfurylidene hydrazide of 3-pyridinecarboxylic acid as particularly potent. Full article