Search Results (290,221)

Background: Peer-assisted learning (PAL) is used in medical education. Its impact in basic medical sciences remains unexplored, namely considering the perspectives of all the populations involved: students, undergraduate teaching assistants (UTAs), and faculty members. We evaluated the educational impact of a PAL programme in Histology and Embryology in a medical course at the Faculty of Medicine of the University of Porto (FMUP). Methods: A cross-sectional convergent mixed-methods study was conducted in the Histology and Embryology course. Tailored online questionnaires comprising Likert-type items and open-ended questions were replied to by students attending theoretical–practical classes with UTAs, the UTAs, and the professors. Internal consistency was assessed using Cronbach’s alpha. Students’ theoretical–practical examination scores were compared between classes with and without UTAs using the Mann–Whitney U test, and effect size (r) was calculated to estimate the magnitude of differences observed. Results: Students (n = 190) reported highly positive perceptions regarding the creation of a more approachable learning environment, clarification of doubts, and identification of histological structures and strongly recommended the extension of UTAs to other courses of the medical school. UTAs (n = 17) described gains in disciplinary understanding, broader perspectives on the medical curriculum, communication and public-speaking skills, teamwork, leadership, self-confidence, and interest in academic careers. Professors (n = 6) valued PAL for improving individual support, facilitating time management, and contributing to UTA training, while highlighting the need for structured pedagogical preparation. Students attending classes with UTAs achieved significantly higher theoretical–practical examination scores (p = 0.04; effect size r = 0.12). Conclusions: PAL was perceived as highly beneficial by all groups involved in the project, enhancing the learning environment, supporting knowledge consolidation, and developing pedagogical and interpersonal skills. A grade analysis indicated that PAL was associated with improved academic performance. These findings reinforce the value of integrating PAL initiatives into preclinical medical education while highlighting the importance of sustained tutor preparation and supervision. Full article

Monitoring the condition of grasslands is essential given their vital role in food security, carbon sequestration and other ecosystem services. Harvested aboveground biomass (HAB) and aboveground net primary production (ANPP) are among the most important grassland state indicators. However, spatially explicit production estimates are largely lacking, and grassland area estimations also remain uncertain. This study addresses these gaps for drought-prone Central European grasslands over 2017–2024. We synthesized grassland extent data, collected extensive field measurements on biomass (BM), and used remote sensing-based biophysical proxies to build an ensemble of six linear models for spatial extrapolation at 10 m resolution. Bayesian framework was used for the linear model fitting that also considers uncertainty of the observations. The ensemble mean ANPP was 310.7 ± 19 gBM m⁻², with modest interannual variability. Upscaled country-wide mean ANPP was 34.3 ± 13.3 Mt year⁻¹. The results indicate that, within the frame of the present study, the remote sensing-based linear model selection has a larger influence on the country totals than the grassland area database selection. The results highlight that both grassland area uncertainty and model construction are major sources of uncertainty in biomass estimation that have to be addressed in future studies. Full article

Background and Objectives: Health systems increasingly require workforce governance approaches that move beyond formal qualifications and make physician skills more visible for planning, education, quality management, and resource allocation. However, evidence remains limited on how physician skill information is organisationally documented and used within hospitals, particularly in small health systems. This study examined how information on physician skills is organisationally documented, interpreted, and used for workforce governance across all Latvian university hospitals, and identified organisational, cultural, and digital barriers to systematic skills monitoring. Materials and Methods: A qualitative, exploratory, multi-institutional design was adopted. Semi-structured interviews were conducted with 12 stakeholders from human resources, education, quality, and finance across all three Latvian university hospitals. Data were analysed using reflexive thematic analysis, with reporting guided by COREQ and SRQR. Results: Eight interrelated themes were identified across three domains. Current practices were fragmented and primarily focused on formal qualifications rather than verifiable practical skills. Internally delivered education was partially documented, whereas externally acquired skills remained largely outside organisational systems. Skill gaps were usually identified reactively through incidents, complaints, or managerial observation. Training needs were determined through decentralised channels, and skill assessment depended heavily on local leadership judgement. Participants also highlighted financial blind spots, weak digital infrastructure, governance ambiguity, cultural resistance, and limited staffing capacity as barriers to implementation. At the same time, respondents consistently reported that improved skill visibility could support strategic workforce planning, targeted education, patient safety, better financial justification, and greater organisational transparency. Conclusions: Latvian university hospitals appear to recognise the organisational value of physician skill visibility but currently lack integrated systems for capturing and using such information systematically. The findings support the need for a context-sensitive, phased approach to skills-based workforce governance and inform a data-informed conceptual framework (Three-Layer Skills Governance Model) for aligning regulatory expectations, organisational processes, and individual skill records in small health systems. Full article

Background: Cervical dumbbell-shaped neurogenic tumors occurring at two noncontiguous levels are rare, and postoperative cerebrospinal fluid (CSF) collection causing cord compression is an uncommon but serious complication after intradural tumor resection. Case Presentation: A 30-year-old man presented with a 3-month history of progressive gait disturbance. Neurological examination revealed grade 3 paraparesis with upper motor neuron signs. Magnetic resonance imaging (MRI) demonstrated two discrete dumbbell-shaped neurogenic tumors located at the C1-2 and C7-T1 levels. The lesions were simultaneously resected. Complete removal of the C1-2 tumor required total sacrifice of the left C2 nerve root, while the C7-T1 lesion was excised through a T-shaped dural incision. The dura was closed primarily with watertight sutures reinforced with dural sealant, and no CSF leakage was observed during intraoperative Valsalva testing. Two months postoperatively, the patient developed worsening upper back and trapezial pain with severe scapular swelling. MRI revealed a large CSF collection extending from C6 to T5, causing moderate cord compression. Urgent revision surgery was performed. Controlled drainage was attempted to prevent intracranial hypotension, but significant CSF egress occurred. The dural defect was repaired using an autologous muscle plug reinforced with fibrin glue. The patient recovered uneventfully after revision surgery and was discharged without recurrence or complications. Conclusions: This case highlights that delayed, extensive postoperative CSF collection can occur despite apparently watertight primary closure and negative intraoperative Valsalva testing. Clinical vigilance for this complication is essential when patients present with new axial pain or localized swelling following cervical intradural surgery, even in the absence of classic low-pressure headaches. Full article

Background: Dermoscopy has increased the excision of very small pigmented lesions in routine practice, yet the diagnostic efficiency of excising lesions ≤ 6 mm judged suspicious for melanoma remains incompletely defined. Objectives: The objectives of this study were to quantify melanoma detection yield and number needed to excise (NNE) for pigmented lesions ≤ 6 mm excised after clinical and dermoscopic suspicion of melanoma and to describe melanoma characteristics according to lesion diameter. Methods: We performed a retrospective observational cross-sectional study at a tertiary dermatologic oncology referral center within the Tuscany Regional Health Service, Florence, Italy. All pigmented lesions excised between 1 January 2022 and 31 December 2023 were screened. Consecutive lesions were included if they were excised because melanoma or suspected melanoma was the preoperative clinicodermoscopic diagnosis; lesions removed for benign or cosmetic indications were excluded. Primary outcomes were melanoma yield and number needed to excise, overall and stratified by clinical diameter. Multivariable logistic regression was performed to assess whether lesion diameter was independently associated with melanoma diagnosis after adjustment for age, sex, and anatomical site. Results: Among 2240 included excisions, 609 melanomas were diagnosed, corresponding to an overall yield of 27.2%. Lesions ≤ 6 mm accounted for 1331 excisions and yielded 175 melanomas, with a yield of 13.1% and a number needed to excise of 7.6. Lesions > 6 mm accounted for 909 excisions and yielded 434 melanomas, with a yield of 47.7% and a number needed to excise of 2.1. Thus, 86.9% of excised lesions ≤ 6 mm were benign on histopathology. Melanomas diagnosed in lesions ≤ 6 mm showed a more favorable histopathologic profile than larger melanomas. In multivariable analysis, lesions > 6 mm had significantly higher odds of melanoma than lesions ≤ 6 mm after adjustment for age, sex, and anatomical site (adjusted odds ratio 4.77, 95% confidence interval 3.81–5.97; p < 0.001). Conclusions: In routine practice, excision of dermoscopically suspicious pigmented lesions ≤ 6 mm has markedly lower melanoma yield and higher NNE than excision of larger lesions. These findings support risk-stratified management approaches and careful consideration of excision thresholds for very small lesions. Full article

Each financial market carries a unique “fractal signature” with its own distinct risk and return pattern. This study comparatively deciphers these fractal signatures of the leading stock market indices of the Emerging Seven (E7) countries (Turkey, India, Brazil, Mexico, Russia, China, Indonesia), using Multifractal Detrended Fluctuation Analysis (MFDFA) with data covering the 2021–2025 period. The findings reveal that all examined markets deviate from the classical random walk model and exhibit distinct multifractal characteristics. However, significant differences were observed among these signatures: in contrast to Russia’s chaotic structure, which showed extreme fragility to geopolitical shocks, the Chinese and Mexican markets presented a more stable and homogeneous risk profile. In all indices, it was found that small-scale fluctuations carry a strong long-memory effect (stable trends), while large-scale fluctuations assume a more random character (sudden shocks). This asymmetric behavior confirms the heterogeneous nature of investor expectations. For example, the generalized Hurst exponents H(q) ranged from 0.22 (RTS, Russia) to 0.73 (BIST100, Turkey), and the spectrum width Δα varied between 0.10 (Mexico) and 0.45 (Russia), confirming significant heterogeneity in market complexity. Turkey’s BIST100 index, with its structure encompassing both predictable and sudden-shock-prone dynamics, occupies a balanced position within this spectrum. Consequently, the study confirms that understanding these unique fractal signatures of emerging markets is a fundamental prerequisite for formulating effective risk management strategies and achieving global portfolio diversification. Full article

The scarcity of resources has constrained the supply of conventional feedstuffs for livestock production. Consequently, mulberry (Morus spp.), known for its high protein content and bioactive compounds, has been developed as a promising alternative feed. However, the optimal water–fertilizer ratio for cultivating feed mulberry and the underlying physiological and agronomic mechanisms remain poorly understood. To address this, a two-year field experiment (2023–2024) was conducted to investigate the effects of water–fertilizer coupling on feed mulberry yield, water use efficiency (WUE), and soil quality. This experiment employed a split-plot design with three irrigation levels (I1 = 45, I2 = 90, and I3 = 135 mm) and four fertilizer rates (F1 = 0, F2 = 150, F3 = 225, and F4 = 300 kg·ha⁻¹). The results demonstrated the following: (1) The variation trends in SWC were consistent with those of soil available N, P, and K contents. Under water–fertilizer coupling, the total water consumption peaked in the I3F3 treatment, with values of 639.9 mm and 703.5 mm in the two years, respectively. (2) The I3F3 treatment produced both the highest yield (37.19 and 41.66 t·ha⁻¹) and the highest leaf N, P, and K contents among all treatments. (3) Water and fertilizer use efficiencies exhibited parabolic trends in response to increasing irrigation and fertilizer inputs. The highest agronomic nitrogen efficiency (AEN) was observed in I2F2. (4) The AMOS 26 model further revealed that soil nutrient content had the strongest direct positive effect on yield (standardized coefficient = 0.68), followed by total water consumption (0.33). And irrigation significantly enhanced soil nutrient availability (standardized coefficient = 0.29). In summary, the I3F3 combination achieved the highest yield and water use efficiency, whereas the I2F2 treatment exhibited the highest AEN. This trade-off suggests that the optimal strategy depends on management objectives (yield maximization vs. resource conservation) in the North China Plain. Full article

Bone is a dynamic specialized connective tissue that undergoes continuous remodeling to preserve its health. Bone health is influenced throughout life by a combination of genetic, hormonal, and environmental factors, as well as physical activity and diet. This study aims to evaluate the effects of diets with different fat content on the femurs of mice fed for 16 or 20 weeks on a normal diet (ND16w and ND20w) or a Western diet (WD16w and WD20w) and for 20 weeks with their combinations on a ketogenic diet (KD) (WD + ND20w, ND + KD20w, and WD + KD20w). Micro-CT analysis on femoral cancellous bone revealed a non-significant trend toward decreased bone volume fraction (BV/TV) and trabecular thickness in mice fed a combined WD + KD20w compared to WD20w. Cortical bone thickness was significantly lower in mice fed WD16w and WD20w compared to those fed ND16w and ND20w (p = 0.049 and p = 0.039, respectively), in mice fed WD20w Ct.Th increased compared to WD + ND20w (p = 0.024) and a strong decrease is evident when comparing WD + ND20w to WD + KD20w (p < 0.0004). Consistently, histological analysis revealed that the number of osteoclasts per bone perimeter on cancellous bone increases compared with ND20w with ND + KD20w (p = 0.007) and WD + ND20w with ND + KD20w (p = 0.0006). In addition, a decrease in osteoblasts was observed (p < 0.041) in cortical bone, comparing ND20w with ND + KD20w; this suggests that the KD may have differential effects depending on the baseline condition. Osteocyte numbers did not significantly change when comparing the different treatments. Masson staining supports micro-CT results on both cortical and cancellous bone. In conclusion, transition from a high-fat diet to a normal diet may partially restore cortical bone health, whereas transition to a ketogenic diet exerts a trend toward additional detrimental effects on trabecular bone. Full article

Background: Pembrolizumab-containing regimens have become the standard of care across the spectrum of triple-negative breast cancer (TNBC). While their use in the neoadjuvant setting is independent of biomarker status, their application in metastatic disease remains strictly contingent upon PD-L1 expression. Given that PD-L1 prevalence can vary significantly by ethnicity and geography, the lack of specific data for the Mexican population creates a challenge for optimizing treatment in the metastatic setting. This study sought to characterize PD-L1 positivity rates in a Mexican TNBC cohort to better define the local molecular landscape. Methods: We conducted a retrospective study across two cancer centers in Mexico to assess PD-L1 positivity in a cohort of women with TNBC (stages I–IV) diagnosed between 2006 and 2021. PD-L1 expression was assessed and evaluated centrally using the 22C3 pharmDx assay, with a Combined Positive Score (CPS) of ≥1 considered positive. We explored the association between PD-L1 expression and clinicopathological features. Results: Of the 298 TNBC patients identified, 285 (96%) had sufficient tissue for CPS evaluation and thus were included in the analysis. PD-L1 positivity was observed in 29.1% of the cohort, and 13.3% of patients had a CPS ≥ 10. PD-L1 positivity was associated with higher histological grades (91.3% vs. 78.5%, p = 0.035) and TILs ≥ 30% (22.2% vs. 10.0%, p = 0.007). Additionally, pre-treatment surgical specimens were more frequently PD-L1 positive than tumor biopsies (56.6% vs. 30.7%, p < 0.001). Conclusions: This study characterizes the PD-L1 landscape in Mexican women with TNBC, reporting a 29.1% prevalence of CPS ≥ 1. The strong association between PD-L1 positivity and high TILs/histological grade highlights the role of the immune microenvironment in these aggressive phenotypes. Given the significant variability observed between specimens (biopsy vs. surgical), clinicians should consider the dynamic nature of PD-L1 expression when choosing treatment strategies. Full article

Cranial cruciate ligament disease (CCLD) is among the most common orthopedic conditions in dogs, and tibial plateau leveling osteotomy (TPLO) is the current standard of care; however, long-term radiographic data on tibial plateau angle (TPA) stability specific to small-breed dogs (<10 kg) remain limited. This retrospective study evaluated radiographic correction and long-term stability of TPA following TPLO in small-breed dogs and assessed whether observed TPA changes fell within the range of measurement error. Thirty stifles from 25 small-breed dogs (body weight 2.56–9.46 kg) that underwent TPLO between 2022 and 2025 were reviewed, with a mean follow-up of 12.6 ± 6.8 months. TPA was measured preoperatively, immediately postoperatively, at 1–2 months, and at ≥6 months using digital orthopedic planning software. Preoperative TPA averaged 31.23 ± 4.60° and decreased to 4.68 ± 1.84° immediately after surgery; at ≥6 months, mean TPA was 5.19 ± 1.83°. The mean change (ΔTPA) was 0.52 ± 0.64° (95% CI: 0.28–0.75°). Although statistically significant (p < 0.001), this fell below the 1.5° intraobserver measurement error previously reported. Body weight showed no correlation with ΔTPA (r = −0.059, p = 0.756). These findings were robust in a sensitivity analysis restricted to one stifle per dog (n = 25; mean ΔTPA 0.56 ± 0.67°) and in the subgroup without concurrent medial patellar luxation (n = 19; mean ΔTPA 0.40 ± 0.49°), both remaining within the reported measurement error. TPLO achieved effective and radiographically stable TPA correction in small-breed dogs. Full article

DeFi perpetual futures have expanded from crypto-native instruments to tokenised equities and commodities, yet the economics of these instruments remain poorly understood. We study 17 assets—5 crypto coins, 8 tokenised equities, and 4 tokenised commodities—on three DeFi perpetual platforms (Hyperliquid, EdgeX, Lighter) over July 2025 to February 2026. Applying a rolling 3-day t-test to identify abnormal trading volume without a predetermined event calendar, we document 1797 statistically significant volume anomalies. DeFi perpetual volume is driven primarily by macroeconomic and policy shocks (ADA $t=+628$ on the U.S. Crypto Strategic Reserve announcement; 15 of 17 assets simultaneously anomalous during January 2026 mega-cap earnings), asset-class-specific catalysts, and a recurring 24/7 market-structure effect tied to weekends and U.S. holidays. Price tracking accuracy reveals a sharp maturity gradient: crypto coin perpetuals exhibit near-perfect price tracking ($\rho \ge 0.999$) and strong TradFi volume co-movement ($\rho \left(0\right)\in [0.72,0.83]$), while equity perpetuals show weaker integration and commodity perpetuals range from adequate (oil, gold) to unreliable (natural gas). We conclude that crypto DeFi perpetuals constitute credible synthetic economic claims on underlying assets, while equity and commodity perpetuals remain at an early developmental stage. Integration with traditional financial markets is well-established for crypto coin perpetuals; for equity and commodity perpetuals, the evidence is preliminary, given short observation windows, and further research with longer time series is needed before definitive conclusions can be drawn. Full article

KRTAP24-1 belongs to the high-sulphur KAP family and has been associated with cashmere fibre diameter in goats, but its role in ovine wool traits remains unclear. This study assessed KRTAP24-1 tissue expression by RT-qPCR and investigated genetic variation and associations with wool traits in 277 Tibetan sheep. Polymorphisms in the coding region were identified by PCR amplification and Sanger sequencing, and genotyping was performed using PARMS. A linear mixed model (LMM) incorporating a genomic relationship matrix (GRM) was used to evaluate associations between SNPs, haplotypes, and 12 wool traits. Bioinformatic analyses were restricted to the five haplotypes observed in the study population and were used as preliminary in silico assessments. Three missense SNPs were identified: c.191C>T (p.L64P), c.527G>A (p.G176D), and c.656C>T (p.A219V). The c.191C>T variant was associated with mean fibre length (MFL), single fibre tenacity (SFT), and scoured yield (SY), whereas c.656C>T was associated with lock length (LL) and clean fleece yield (CFY). Several haplotype combinations were also associated with LL, elongation at break (EB), and CFY. KRTAP24-1 showed high expression in skin. The observed haplotypes showed only minor differences in predicted mRNA secondary structure and mainly local changes in predicted protein features. These findings suggest that KRTAP24-1 may provide a preliminary basis for marker-assisted selection in Tibetan sheep breeding, but its functional role requires further validation in independent populations and experimental systems. Full article