Abstract: The degree of polarization is usually obtained from the coherency matrix or, equivalently, from the mean Stokes vector of a partially polarized optical field. Here, we adopt a complementary geometric viewpoint by representing normalized local Stokes vectors as random directions on the Poincaré sphere. When these directions are described by an effective unimodal von Mises–Fisher distribution, the concentration parameter gives a direct one-to-one description of the degree of polarization through the mean resultant length. This formulation does not define a new independent polarization observable. Instead, it gives the degree of polarization a rotation-invariant information-theoretic meaning, expressed in terms of directional concentration and angular disorder. Within this framework, we derive closed-form expressions for the differential entropy of the von Mises–Fisher distribution and for the Kullback–Leibler divergence between two directional polarization states. The symmetrized divergence further incorporates both differences in concentration and relative orientation on the Poincaré sphere. We also discuss the assumptions, range of validity, and limitations of the single-vMF model, particularly in relation to Gaussian-field statistics and to more general directional models needed for anisotropic or multimodal polarization fluctuations. Overall, this formalism establishes a model-based theoretical framework for entropy and divergence descriptors of unimodal directional polarization and suggests natural extensions toward mixtures of vMF, Bingham, or Kent distributions.

Abstract: Background/Objectives: In Brazil, its rates remain persistently high and disproportionate, highlighting severe racial and social inequities that predominantly affect the Black population. The objective is to analyze racial inequalities in maternal mortality in Brazil (2000–2023), identifying sociodemographic, regional, clinical and temporal patterns, with an emphasis on the impact on Black women. Methods: A retrospective population-based cohort study was conducted using data from Brazil's Mortality Information System between 2000 and 2023. A total of 40,907 maternal deaths among women aged 10–49 years were included. Maternal mortality ratios were calculated, and adjusted Poisson regression models were used to examine associations between maternal mortality and race/skin colour, age, education level and region of residence. Results: Black and Brown women accounted for 59.2% of maternal deaths and experienced a significantly higher risk of maternal mortality than White women, while Indigenous women had more than twice the risk. Lower educational attainment, residence in the North and Northeast regions, and maternal age ≥40 years were also independently associated with increased mortality risk. Direct obstetric causes accounted for 65.9% of maternal deaths, with hypertensive disorders and childbirth-related complications among the most frequent causes. The immediate postpartum period represented the highest-risk period, accounting for 47% of deaths. More than half of women had no more than primary-level education, and 50.3% were single. Conclusions: Maternal mortality in Brazil remains characterised by substantial racial, educational and regional inequalities. Indigenous, Black and Brown women, women with lower educational attainment, and those residing in the North and Northeast regions experienced disproportionately higher mortality risks. These findings highlight the need for targeted public health and maternity care interventions to reduce preventable maternal deaths and improve equity in maternal health outcomes.

Abstract: Background: Fournier's gangrene (FG) is a rare, rapidly progressive necrotizing soft-tissue infection associated with high mortality. Early identification of high-risk patients remains essential, but the comparative performance of prognostic scores and the impact of Sepsis-3 classification and malignancy status remain incompletely de-fined. Methods: We conducted a retrospective observational cohort study including 21 con-secutive adults with surgically confirmed FG treated at a tertiary referral center be-tween 2019 and 2025. Clinical characteristics, Sepsis-3 classification, malignancy sta-tus, and admission severity scores (FGSI, SFGSI, LRINEC, and NLR) were analyzed. Prognostic performance was assessed using ROC analysis, while associations with in-hospital mortality were evaluated using Fisher's exact test and Firth's bias-reduced logistic regression. Results: In-hospital mortality was 19.0% (4/21). FGSI showed the highest predictive accuracy (AUC 0.934), followed by SFGSI (AUC 0.919), while LRINEC performed well (AUC 0.860) and NLR showed limited discrimination (AUC 0.574). Confirmed Sepsis-3-defined sepsis occurred in 33.3% of patients and was strongly associated with mortality (57.1% vs. 0%; p = 0.006). Although 76.2% presented with confirmed or probable sepsis, all deaths occurred exclusively in patients with or-gan dysfunction. Metastatic malignancy was observed only in non-survivors and was significantly associated with mortality (100.0% vs. 10.5%; p = 0.029). No severity score correlated with hospital length of stay. Conclusions: FGSI and SFGSI demonstrated excellent prognostic performance. Sepsis-3-defined organ dysfunction and metastatic malignancy emerged as strong predictors of mortality, suggesting that their integra-tion into future prognostic models may improve early risk stratification and individu-alized management in patients with FG.

Abstract: Unmanned aerial vehicle (UAV) swarms increasingly operate in GNSS-denied environments, where cooperative localization provides relative positioning by fusing onboard odometry with inter-agent range measurements, for which ultra-wideband (UWB) two-way ranging is a common infrastructurefree choice. Beyond accuracy, safe swarm autonomy needs a trustworthy measure of positioning uncertainty, since collision-avoidance and formation-keeping decisions derive their safety margins from the reported covariance. Under sustained agile flight, both are hard to achieve at once: motion within each time-division polling round induces a ranging bias well above the UWB noise floor, and reusing shared information across the network drives the reported covariance below the true error. To address these two problems jointly rather than in isolation, we propose a modular architecture coupling an online maximum-likelihood polynomial least-squares (MPLS) ranging front-end with a fading split covariance intersection (SCI) cooperative back-end through a per-link variance interface: online MPLS compensates the motion-induced bias and reports a calibrated, time-varying variance that fading SCI consumes as measurement noise while its continuous-time fading factor bounds the reused-information covariance. Monte Carlo simulation over anchored and anchor-free 16-node swarms shows the two effects to be empirically decoupled, with front-end ranging quality governing positioning accuracy and back-end correlation handling governing estimator consistency. The method attains sub-meter positioning accuracy in both settings and, without per-scenario tuning, keeps consistency—quantified by the average normalized estimation error squared (ANEES)—within a trusted band; comparably accurate extended Kalman filter and covariance-intersection baselines fall outside it, becoming overconfident and over-conservative, respectively. It thus delivers the trustworthy uncertainty that safety-critical swarm decisions require in GNSS-denied flight.

Abstract: This paper investigates hallucinations in large language models from the perspective of structured extraction, using prompt-based Semantic Role Labeling (SRL) as a controlled case study. SRL requires exact span boundaries and role assignments, while prompting constrained by rationales exposes the reasoning trace associated with each prediction. Our approach employs a DSPy-based pipeline with rule-grounded signatures to show that hallucinations in constrained extraction are systematic, rationale-associated, and thus amenable to targeted mitigation through signature design. Experiments on a representative subset of the CoNLL-2012 dataset show that hallucinations persist even under constrained settings and are systematically associated with failures of rule grounding. Because each prediction is required to cite a single governing rule, errors can be organized and aggregated at the rule level without necessitating additional classification. Leveraging these observations, we introduce a Rationale-Oriented (RO) optimizer that targets such failures by selectively rewriting the relevant parts of the signature. This process mitigates systematic failure modes and leads to measurable improvements in precision, recall, and F1 across multiple evaluation settings, using a representative subset of argument roles aligned with a 5W+1H schema and no model fine-tuning. Signature-perturbation experiments show that cited rules act as diagnostic proxies rather than per-instance causal explanations: the model's parametric priors also contribute to extraction. Even so, rule-level aggregation remains a reliable predictor of where errors occur. These findings suggest that hallucination in structured tasks is closely linked to failures in instruction grounding, and that rule-level feedback and refinement offer a framework for improving reliability in prompt-based systems.

Abstract: The present study was conducted to investigate the effect of dietary supplementation with the probiotic Zoovit LL – alone or combined with phytogenic additives – on bone mor-phometry and bone mineral composition in broiler chickens via computed tomography (CT) and bone mineral profile analysis. To this end, 180 day-old male ROSS 308 chicks were randomly divided in three groups: control (standard diet), experimental supple-mented with Zoovit LL probiotic (0.25%) and experimental supplemented with Zoovit LL probiotic (0.25%) combined with Silybum marianum, Urtica dioica and Taraxacum officinale phytogenic additives (1%). At the end of the trial period, femoral bone samples were col-lected for CT morphometric and densitometric analysis consisting of bone length, cortical thickness and radiodensity determinations. Also, sternum samples were obtained for ICP-MS analysis of the mineral bone composition (calcium, phosphorus and magnesium). The trial duration was 42 days, under controlled rearing conditions. The results showed statistically significantly lower femur length in the probiotic-supplemented group compared to the probiotic-herb group. Regarding the other studied morphometric param-eters, cortical bone density, cortical structural indices and bone mineral content, no statis-tically significant between-group differences were found. Bone density tended to be greater in supplemented groups, especially when the probiotic was co-administered with phyto-genic substances.

Abstract: Decades of progress in global sexual and reproductive health programming and data availability are threatened as over 80% of donor funding for family planning (FP) comes from governments that have announced significant cuts to Official Development Assistance. This commentary examines how FP2030 is adapting its Measurement Framework and annual reporting given uncertainty around the future of household surveys, such as the Demographic and Health Survey, and the loss of technical resources. FP2030 will pivot from reporting on 22 indicators to a “minimum set” of 15 priority indicators. FP2030 arrived at these recommendations through consensus built during a series of working meetings with its Performance Monitoring and Evidence Working Group (PME WG), a group of FP measurement experts. The 15 indicators leverage existing mathematical models and health management information systems (HMIS). Moreover, this commentary provides a complementary set of indicators that should be prioritized if new data collection opportunities arise. Ultimately, while FP2030 and the PME WG believe that models and HMIS data will become more essential, these tools cannot fully replace household surveys. Continued investment in FP data availability remains critical to ensuring the community can review data that protects the rights and needs of individuals through current programming.

Abstract: Recombinant AAV (rAAV) production in HEK293 cells has advanced through separate optimizations of individual intervention points: raising ATP levels, inhibiting the proteasome, suppressing apoptosis, or increasing Rep52/40 stoichiometry. However, when these results are considered together, each intervention produces counterintuitive trade-offs. This paper argues that these trade-offs are not anomalies but the expected behavior of a coupled system in which intracellular ATP serves as a shared control variable for three manufacturing outputs: particle yield, capsid integrity, and producer-cell longevity. I describe four mechanistic couplings that link ATP to these outputs. First, ATP directly fuels the Rep52/40 packaging motor, making the encapsidation rate sensitive to the cytosolic energy supply. Second, physiological millimolar ATP suppresses 26S proteasome activity in a biphasic, concentration-dependent manner, sparing nascent capsid precursors and Rep proteins (productive arm) while simultaneously stabilizing p53 and sensitizing cells to apoptosis (destructive arm). Third, proteasome suppression also spares the MRN replication-restriction complex, predicting a non-monotonic, window-shaped yield response to increasing ATP. Fourth, the apoptosis node receives at least three mechanistically distinct death inputs, none of which is fully addressed by single-branch interventions. From this coupling structure, the model makes five falsifiable commitments, each specifying experimental results that would challenge it. The framework re-derives recent trade-off findings in the field, including contradictory results from pan-caspase and HIF1α inhibition, as predictable outcomes of a constrained system rather than isolated anomalies. It further predicts that coordinated improvement in yield requires joint control of both the ATP set-point and the apoptosis node.

Abstract: Engineering laboratory pedagogy is often framed through binaries such as collaboration versus autonomy, structure versus flexibility, and in-person participation versus alternative modes of engagement. This exploratory mixed-methods study examines how these preferences coexist within individual students rather than treating them as mutually exclusive orientations. Data were drawn from an end-of-term self-reflection survey completed by 50 students in an undergraduate engineering laboratory course at a public university in the US. Closed-ended responses were analyzed through theoretically defined cross-classifications, descriptive comparisons, effect-size estimates, and exact tests, while open-ended responses were used to interpret the resulting preference configurations. The findings revealed substantial overlap among seemingly contradictory preferences. Among students who preferred structured, in-person laboratory sessions, 41.9% also expressed strong interest in greater spatial-temporal flexibility, while 46.5% rated temporal flexibility as highly important. Similarly, 51.1% of students who felt comfortable contributing in groups nevertheless perceived students who prefer working alone as disadvantaged. Students who frequently completed coursework outside standard hours were also especially likely to value temporal flexibility. These findings suggest that engineering students cannot be meaningfully divided into fixed categories of collaborative versus independent or traditional versus flexible learners. Instead, inclusive laboratory pedagogy may be better understood as a configurable learning ecology that preserves structure and social connection while providing meaningful autonomy, flexibility, and multiple pathways for participation.

Abstract: Background: Health literacy (HL), the ability to understand and apply health information, impacts pregnancy outcomes. While group prenatal care (GPC) models emphasize education and social support, no existing reviews evaluate its ability to improve HL relative to traditional prenatal care (TPC). This review aims to evaluate the evidence for GPC as a health literacy intervention compared to TPC. Methods: We searched MEDLINE (Ovid), CINAHL (EBSCOhost), Web of Science (Clarivate Analytics), Embase (Elsevier), APA PsycInfo (ProQuest), Cochrane Library (Wiley), CAB Abstracts (Ovid), and Global Health (Ovid) for peer‑reviewed studies. Eligible studies directly compared pregnant patients in GPC versus TPC, used randomized controlled trial, cohort, or pre–post designs, and assessed HL or shared decision‑making (SDM). No restrictions were applied based on age, risk level, language, or geographic location. We extracted and synthesized HL knowledge scores using the Cochrane RevMan web tool. Risk of bias was assessed using Cochrane RoB 2.0 and ROBINS‑I. Data were pooled using standardized mean differences, as appropriate. We quantified between-study heterogeneity using I2. Results: Eight studies met inclusion criteria, with substantial heterogeneity in design and HL measures. Among four randomized studies, the standardized mean difference was 0.31 points between GPC and TPC (p<.001; 95% CI: 0.24, 0.37; I²=0%). In four non‑randomized studies, women in GPC scored 1.36 points lower than those in TPC, with no statistically significant difference (p=.64; 95% CI: −1.37, 0.85; I²=97%). No studies assessed SDM. Conclusions: GPC is associated with improved HL compared to TPC, particularly in randomized designs, suggesting potential effectiveness as an HL intervention; however, additional high‑quality studies are needed.

Abstract: This study aims to investigate osmoprotectant rhizobacteria producing glycine betaine, marked with the Green Fluorescent Protein (GFP) gene, in the rhizosphere of mung bean plants under drought stress conditions. The transformation of the GFP gene was performed on isolates Bl-19 and Am-7. Seeds were soaked for 30 minutes in bacterial suspensions containing either Bl-19-gfp or Am-7-gfp at a density of 106 cells mL-1, in a volume of 500 mL. The seeds were then planted under drought stress at 60% field ca-pacity and sterile media. The results showed that inoculation of Bl-19-gfp isolates with an initial density of 10⁶ CFU led to a decrease in bacterial density to 1.4 x 10⁵ CFU 1 week after inoculation. Similarly, inoculation of Am-7-gfp isolates with an initial density of 10⁶ CFU caused a decrease to 1.7 x 10⁵ CFU after 1 week of inoculation. Subsequently, the densities of both isolates remained stable from week 2 to week 4. The dry weight of mung bean plants at soil moisture conditions of 60% field capacity using isolates Bl-19 and Am-7 increased by 40.13% and 52.44%, respectively. Based on the results, both isolate increased dry weight below 60% of field capacity in sterile media.

Abstract: Background: Radiography integrates scientific knowledge and technical skill with effective patient interaction and sound ethical judgment to provide quality patient care. Sustained ethical conduct is central to safe, trustworthy radiographic service delivery. However, the extent to which radiographers uphold these standards in Nigerian settings, including Kano metropolis remain in deficit. Objective: This study evaluated adherence to ethics of patient care, professional responsibilities, and continuous professional development among practicing radiographers in Kano metropolis. Methods: A cross-sectional survey was conducted among practicing radiographers in Kano metropolis between April and October 2019 using a validated, structured, self-administered questionnaire. It was distributed to 35 consented radiographers selected by non-probability sampling. Only 27 responded, with a response rate of 77.1%. Data were analyzed descriptively using SPSS version 23.0. Results: Most respondents always adhered to core patient care ethics: accurate patient identification (100%), respect for patient rights and dignity (92.6%), justification of medical exposure (88.9%), and confidentiality (85.2%). Only 29.6% always implemented equipment quality assurance programmes, with 40.7% doing so only sometimes and 7.4% never. Adherence to professional responsibilities and continuous professional development was similarly high (77.8%). Conclusion: Radiographers in Kano metropolis showed strong ethical commitment to patient care and professional responsibility. However, equipment quality assurance implementation was inadequate. Strengthening institutional quality assurance and regulatory oversight is recommended.

Abstract: Aspergillus species are saprophytes, found in soil, decaying matter and on the surface of plants. Some species are pathogens of humans, other animals or plants or cause food spoilage. Invasive aspergillosis affects three million people, mostly immunocompromised individuals, and mortality is around 50% where treatment is provided and almost 100% without treatment. Allergic bronchopulmonary aspergillosis affects five million people, particularly asthmatics and cystic fibrosis patients. Resistance to azole antifungals is rising, possible because of agricultural use of azoles. This review discusses Aspergillus species, aspergillosis and allergic conditions caused by Aspergillus, immune reactions and ways in which Aspergilli counteract immune responses, the rise of antifungal resistance and the dispersal of Aspergillus spores and mycelial fragments and suggests future prospects, including possible research directions and methods of detection and treatment.

Abstract: A set of pointlike inhomogeneities placed on the flat surface of an elastic half-space is put forward as a model for large urban agglomerations, consisting of buildings, constructions, erected on a limited area on Earth’s surface (e.g., cities). Under the action of an incident plane seismic wave a hierarchy of scattered waves arising from these inhomegeneities is identified, and their effect on the pointlike inhomogeneities is analyzed. We show that in the long-wavelength limit the first-order scattered waves are of Coulomb type, i.e. the displacement in these waves goes like the inverse distance from the scattering centres. We estimate the displacement produced by the scattered waves in this case, and find that it is large for large and agglomerated buildings, constructions, placed over large distances, i.e. precisely for what we call "large urban agglomerations". In the short-wavelength limit the Coulomb-like dependence acquires an oscillating factor. In this case we identify a divergent displacement produced by the scattered waves when the incident wave propagates parallel to the surface; leaving aside this special case, a necessary condition for the convergence of the series produced by the hierarchy of the scattered waves is a rare (sparse) distribution of small-size inhomogeneites.

Abstract: International climate finance is widely presumed to accelerate green technological innovation in recipient economies, and recent studies report positive effects. This study examines whether that proposition survives systematic scrutiny. Using OECD ENV-TECH patent indicators and OECD DAC Rio Marker climate-mitigation commitments for 118 developing economies between 2004 and 2022, the analysis estimates 180 specifications based on two estimators, three treatment scalings, five denominator thresholds, alternative trend specifications, and sample restrictions. Although 90% of the estimates are positive and 34% reach conventional significance, significance is confined to two identifiable dependencies. Count-based (quasi-Poisson) models are dominated by China, which accounts for 78.7% of the sample’s inventions despite representing only 10.7% of the world total: all thirty count specifications are significant with China included, and none is significant once China and India are excluded. Fractional-response models on the green invention share are invariant to dropping large recipients but derive their significance entirely from country-years with fewer than four total inventions, where a single patent moves the outcome by tens of percentage points. Of the 48 specifications that both exclude China and impose a minimally informative denominator, none is significant; the median standardised effect is 0.03. The findings indicate no reliable evidence that bilateral climate-mitigation finance raises green innovation, and identify a structural weighting problem that plausibly explains positive results in smaller samples.

Abstract: Background: Tuberculosis (TB) remains a leading cause of infectious morbidity worldwide, with increasing recognition of post-tuberculosis lung disease (PTLD). Structural lung damage begins early in the disease course, often preceding clinical or radiographic detection. Methods: The objective of this study was to review diagnostic approaches for detecting early structural lung damage in TB. A structured narrative review was conducted using PRISMA principles, including studies published between 2018 and 2025. Results: We found high-resolution computed tomography (HRCT) is the most sensitive modality for early structural abnormalities such as tree-in-bud nodules and ground-glass opacities. Pulmonary function tests, particularly DLCO, detect early impairment. Biomarkers such as matrix metalloproteinases (MMPs) and cytokines reflect ongoing tissue damage. Conclusion: We concluded that a multimodal diagnostic approach integrating imaging, functional assessment, and biomarkers enables early detection and may prevent progression to chronic lung disease.

Abstract: Paper mills pose a serious threat to the reliability of the scholarly record, and public critics have often identified cross-journal patterns that conventional editorial processes failed to detect. The legitimacy of this work, however, does not remove the need to calibrate public terminology. When a severe organisational label such as "paper mill" is combined with a national descriptor, the apparent scope of the claim can expand from a defined set of papers to authors, institutions, or an entire research community. This Perspective develops an evidence-and-scope framework for evaluating that expansion. It draws on research about paper mills, citation manipulation, image anomalies, stigma, and research assessment, and it uses the publicly available Science Integrity Digest post "The Iranian Plant Paper Mill" as an illustrative case. The analysis does not determine whether the papers discussed in that post originated from a paper mill and does not allege misconduct by the post's author, commenters, or any researcher mentioned there. Instead, it examines the relationship among the evidence described, the title's geographic referent, the procedural status of the allegations, the use of pseudonymous observations, and the expansion of claims through comments. The article argues that national descriptors are not inherently improper, but they require an explicit analytic purpose, a defined unit of attribution, proportional treatment of transnational participation, and visible uncertainty and update mechanisms. It proposes a staged evidence-to-label vocabulary and a disclosure standard covering dataset boundaries, geographic meaning, verification, right of reply, comment moderation, and post-publication revision. These safeguards are intended to strengthen, rather than restrain, public research-integrity criticism by making serious warnings more precise, auditable, and resistant to collective overgeneralisation.

Abstract: Gonadotropin-releasing hormone agonists are used to treat central precocious puberty and are increasingly prescribed in gender-affirming care. Despite well-established reproductive effects, their broader physiological effects during puberty remain poorly understood. Male and female Wistar rats received a depot triptorelin injection at pubertal onset. Body mass, food intake, and locomotor activity were monitored. After 28 days, reproductive function was assessed, and pituitary and hypothalamic gene expression was analyzed. Changes in gonadal weight, estrous cycle, folliculogenesis, seminiferous tubules’ morphology, and sperm count confirmed the suppression of pubertal maturation. Triptorelin downregulated Gnrhr and Lhb, demonstrating suppression of gonadotrope function. Despite comparable reproductive suppression, metabolic responses to triptorelin were strongly sex-dependent. Females exhibited increased body weight gain accompanied by delayed hyperphagia, whereas males showed reduced body weight gain, unchanged food intake, and increased mean locomotor speed. Female-specific transcriptional remodeling was observed in the hypothalamus, characterized by downregulation of Lepr and Npy and upregulation of Sst and Kiss1 expression. Collectively, these findings demonstrate that pubertal triptorelin treatment induces profound reproductive suppression in both sexes while eliciting sex-specific hypothalamic adaptations in pathways regulating energy homeostasis. This suggests that puberty blockers exert broader neuroendocrine effects beyond the suppression of reproductive maturation.

Abstract: Jeffreys‑rule Bayesian inference for the Poisson mean was retrospectively applied to cytokinesis‑block micronucleus (CBMN) data from four studies conducted in a single laboratory (2001–2026), covering ionising‑radiation exposures in human lymphocytes and an ¹³¹I biodosimetry study (29 experimental groups). The CBMN assay is widely used for cytogenetic biodosimetry and for evaluating radioprotective agents, but classical analysis of net micronucleus (MN) yield becomes unreliable when effective radioprotectors reduce MN frequencies towards background, leading to near‑zero or negative net counts with poorly characterised uncertainty. In our reanalysis, the Bayesian correction systematically modified magnitude-of-protection and dose-reduction estimates in low-count, high‑protection conditions in comparison with the classical approach. Using Bayesian net counts to recalculate standard radioprotective metrics revealed that, while the overall ranking of radioprotective potency was preserved, Bayesian magnitudes of protection and dose reduction factors were consistently lower than their classical counterparts for the most effective radioprotectors administered before irradiation, providing more conservative efficacy estimates with quantified uncertainty. In the ¹³¹I biodosimetry cohort and in patients undergoing diagnostic nuclear medicine procedures, post‑exposure MN yields remained within the spontaneous background variability of the assay, and the Bayesian framework is fully compatible with the practical absence of detectable chromosomal damage at the doses used in routine clinical practice. Taken together, these results demonstrate that Jeffreys‑rule Bayesian inference provides a statistically coherent and practically feasible framework for CBMN analysis in the low‑count regime, stabilising net MN estimates, avoiding artefactual negative values and supplying confidence intervals for radioprotective efficacy metrics. As a concrete methodological recommendation, Bayesian analysis should be adopted as the default approach whenever post‑exposure MN counts are within approximately a factor of two of background, with classical methods remaining adequate at higher count levels.

Abstract: The selection of separation-pier layouts for side inlet/outlet structures in pumped-storage power stations is still largely experience-based, and direct hydraulic comparisons among practical layouts remain limited. This study compares one-, two-, three-, and four-pier layouts under inflow and outflow operation. A three-pier layout from a lower-reservoir side inlet/outlet was used as the reference, while the other layouts followed previously recommended pier-head positions and channel-width ratios. The total trash-rack flow area and the principal longitudinal and elevation dimensions were kept constant. A three-dimensional simulation based on the Reynolds stress model was validated against physical-model measurements; the maximum relative deviations of the evaluated hydraulic indices were below 5%. All four layouts met the prescribed discharge-distribution criterion in both flow directions. Under outflow, however, the maximum velocity non-uniformity coefficients for the one- and two-pier layouts were 2.168 and 2.068, exceeding the allowable value of 2.0, whereas the three- and four-pier layouts yielded 1.920 and 1.838. The head-loss coefficient increased monotonically with pier number in both directions. Consequently, the three-pier layout provided the most favorable engineering trade-off among the four evaluated configurations for the investigated geometry and operating conditions. These results represent a comparison of practical layouts rather than a strict single-factor test of pier number.