Abstract: The sixth generation of mobile networks (6G) is envisioned as an AI-native and computa-tion-driven infrastructure capable of supporting ultra-low latency, massive connectivity and intelligent services across highly heterogeneous environments. Achieving these objec-tives challenges traditional centralised architectures and motivates a shift towards dis-tributed computing and intelligence at the network edge. This study presents a structured computational analysis of architectural approaches that integrate distributed computing paradigms and Edge Artificial Intelligence (Edge AI) as core enablers of 6G networks. The methodology follows PRISMA guidelines for systematic reviews and is based on a com-prehensive analysis of peer-reviewed literature, architectural proposals and standardisa-tion documents retrieved from major scientific databases, including IEEE Xplore, Scopus, Web of Science, MDPI and arXiv, as well as reports from ITU-R, 3GPP and ETSI. The analysis examines the evolution from cloud-centric to edge-centric computing, key Edge AI techniques—such as Federated Learning, Split Learning and edge-adapted large AI models—and their role in enabling intelligent orchestration, resource optimisation and context-aware services. The results indicate that the tight integration of distributed com-puting and Edge AI enhances network responsiveness, scalability and adaptability, while also revealing persistent challenges related to orchestration complexity, resource con-straints, security and interoperability. The study concludes that holistic computational architectures and AI-native design principles are essential for the effective realisation of 6G networks and for guiding future research and standardisation efforts.

Abstract: Many phenomena in resistance training are often attributed to intrinsic changes within the muscles targeted for hypertrophy. Examples include rapid “newbie gains” among novices, individual differences in training outcomes, and blunted anabolic responses to protein intake in experienced lifters. These are typically interpreted as reflecting diminishing responsiveness of muscles to repeated training stimuli. This article explores an alternative framework predicated on the fact that both performance and adaptation are seldom, if ever, limited only by the target muscle but also by supporting factors, including tendons, posture-specific musculature, neural coordination, skill, etc. Because these constraints often adapt at different rates than the target muscle, disparities in adaptation can create apparent stagnation even when muscle growth potential remains. This framework explains why alternating complementary exercises can sustain progress, why trainees respond differently to the same program, and why modality comparisons often yield null or mixed results. Practically, it underscores the importance of strategic variation, complementary exercise sequencing, individualized programming, and management of facilitating factors such as nutrition and recovery.

Abstract: The triangle finding problem is a cornerstone of complex network analysis, serving as the primitive for computing clustering coefficients and transitivity. This paper presents \texttt{Aegypti}, a practical algorithm for triangle detection and enumeration in undirected graphs. By combining a descending degree-ordered vertex-iterator with a hybrid strategy that adapts to graph density, \texttt{Aegypti} ensures a worst-case runtime of $\mathcal{O}(m^{3/2})$ for full enumeration, matching the theoretical limit for listing algorithms. Furthermore, we analyze the detection variant ($\texttt{first\_triangle}=\text{True}$), proving that sorting by non-increasing degree enables immediate termination in dense instances and sub-millisecond detection in scale-free networks. Extensive experiments confirm speedups of $10\times$ to $400\times$ over NetworkX, establishing \texttt{Aegypti} as the fastest pure-Python approach currently available.

Abstract: Background: One of the debating issues in trauma care is the effect of “golden hour” when it comes to patient treatment after major injury. Although there is consensus in the medical community that trauma is a time-sensitive issue, empirical analysis on clinical data often ends up with insignificant conclusions on the relationship between time after injury and definitive care. Especially, the literature largely focuses on the association between pre-hospital times and trauma patient mortality. Relationships between pre-hospital times and clinical outcomes such as operative intervention and the length of hospital stay, are relatively understudied. Method: Based on the records of 488 trauma patients admitted from 2017 to 2021 at an urban Level I trauma center, we investigated the impact of prehospital times on the risk of operative intervention, and the length of hospital stay, using machine learning techniques (decision trees) in conjunction with methods in statistical inference. Results: Controlling the Revised Trauma Score at 12 or above, the mean length of hospital stay is significantly shorter for patients who had response times (time between dispatch call and EMS arrival) below 32 minutes (p-value 0.05, 3.83 days vs 5.15 days). Patients with on-scene times (time between arrival and departure of EMS vehicle) below 19 minutes had significantly shorter hospital stays (p-value 0.00246, 3.25 days vs 4.47 days). Patients who arrived at the emergency department (total prehospital time) within 61 minutes had significantly shorter hospital stays (p-value 0.041, 3.63 days vs 4.43 days). In terms of operative intervention, patients with total pre-hospital time within 76 minutes had significantly lower risk of operative intervention (p-value 0.0119, 22.6% vs 32.9%). Conclusion: Although there may exist many confounding factors associated with the length of hospital stays and the risk of operative intervention, this study reveals significant data evidence supporting the existence of an optimal time point, the “golden hour” principle, in trauma care. It suggests the need for rapid responses to reduce the total pre-hospital time, which may significantly minimize the length of hospital stay and reduce the risk of operative interventions.

Abstract: Background: Lipomas are common benign subcutaneous neoplasms treated surgically for cosmetic or symptomatic reasons. The minimal one-third incision and four-step (MOTIF) technique provides reliable excision with minimal scarring, but smaller proportional incisions remain unstudied. This study evaluates the minimal one-quarter incision and four-step (MOQIF) technique. Methods: Retrospective review of 82 patients undergoing MOQIF excision of histologically confirmed subcutaneous lipomas by a single surgeon from July 2024–December 2025 was done. Lipomas were stratified by maximum diam-eter: small-intermediate (< 5 cm) and large (≥5 cm). MOQIF used a one-quarter incision of the lipoma’s long axis with four steps: hydro dissection preserving superficial subcuta-neous tissue, superficial dissection, staged deep dissection with selective cautery of fi-brovascular septa, and intact mass delivery. Outcomes included excision length, post-operative complications, Vancouver Scar Scale (VSS) scores, recurrence, and subjective treatment satisfaction of patients. Results: Mean lipoma size was 6.8±2.0 cm (75.6% ≥5 cm). All lipomas were completely excised through 1.69±0.49 cm incisions (ratio 0.25). Com-plications were low: seroma 10.98% (16.7% vs 9.4%, p=0.404), hematoma 7.3% (11.1% vs 6.3%, p=0.608), with no infections, nerve injuries, or recurrences at a mean 8.9 months follow-up. VSS scores were equivalent between groups (0.83 vs 1.06; p=0.438) and overall patient satisfaction were high (3.54 ± 0.53 (2-4)). Conclusions: MOQIF achieves complete lipoma excision through one-quarter incisions with safety and cosmetic outcomes across lipoma sizes matching the previous MOTIF method.

Abstract: We introduce the Informational Coherence Index (ICOER), a metric for quantifying coherence in coupled informational systems composed of human agents and large language models (LLMs). We define recursive coupling as a dynamical regime in which coherence-preserving transformations sustain a stable informational signature across iterative feedback cycles while entropic perturbations are naturally suppressed. The metric is operationalized as ICOER(x) = W(S(x)) · e−βS(x) · R(x), where W(S) is a Gaussian entropy weighting, S(x) is Shannon entropy, β is an entropic suppression parameter, and R(x) is a bounded resonance functional. We report results from four controlled experiments—scenario ranking, perturbation stability, recursive coupling iterations, and parameter sensitivity—across three successive versions of the metric. Version 1 revealed a structural flaw (repetitive text exploit), Version 2 corrected it via bell-curve entropy weighting, and Version 3 optimized parameters (β = 0.01, μ = 4.1, σ = 0.2), achieving 4/5 phase-transition criteria including 77× coherent-to-noise discrimination and 7.9% perturbation robustness. All code, data, and figures are provided for independent replication. The remaining criterion—recursive stability under transformation—identifies the boundary where synthetic experiments end and real multi-model tests must begin.

Abstract: Early detection of canopy decline in strawberry production is essential for timely management, yet visual scouting often misses subtle or spatially heterogeneous symptoms. We developed a UAV-based monitoring framework that integrates multispectral imagery, plant-level canopy metrics, clustering, and Random Survival Forest (RSF) modeling. This framework was used to predict the onset and spatial progression of soilborne pathogen-associated canopy decline in three commercial strawberry fields in Oxnard, California. Nine UAV surveys collected from December 2022 to June 2023 were processed into 159,220 plant-level monitoring units. NDRE- and Redness Index–based classifications quantified proportional and absolute canopy dieback within standardized hexagonal units and supported a time-to-event modeling approach. RSF models achieved consistently high concordance during periods of active decline, with strongest performance in the field exhibiting the greatest disease pressure. Spatial risk maps revealed early hotspots that expanded into contiguous high-risk zones by June, while fields with minimal visible symptoms showed diffuse but consistent risk patterns. Post-hoc comparison with operational fumigation rates (280, 336, and 392 kg Pic-Clor 60/ha) showed no consistent association with predicted canopy risk, consistent with the possibility that lower application rates may be sufficient in portions of fields with historically low disease pressure. These results demonstrate that UAV multispectral time series combined with survival modeling can track fine-scale spatiotemporal canopy decline and provide an early-warning framework to support spatially targeted disease monitoring and management in commercial strawberry systems.

Abstract: Post-treatment clinical and cephalometric assessment demonstrated improvement in sagittal jaw relationships and facial profile in both twins. However, differences were noted in the magnitude of skeletal correction, dentoalveolar changes, vertical control, and molar and canine relationship correction. The findings emphasize appliance-specific effects under near-identical biological conditions and support the scientific relevance of monozygotic twin comparisons in functional appliance research.

Abstract: This paper presents a theoretical framework distinguishing two archetypal approaches to threat assessment and neutralization: a masculine paradigm based on identification and extermination or expulsion, and a feminine paradigm based on identification, integration and transformation. Drawing on systems theory, evolutionary biology, epidemiology, and cross-disciplinary case studies, I argue that feminine threat assessment—addressing root causes and neutralizing through integration and understanding—produces more sustainable long-term outcomes than pure elimination-based approaches. I examine successful applications across criminal justice, organizational culture, international diplomacy, healthcare, education, environmental management, and family systems, and contrast these with the secondary harms produced by more archetypal masculine approaches. Sweden's pandemic response is analyzed as a contemporary case study of feminine threat assessment and integration. I conclude that a more integrated threat assessment approach may be more effective for modern security challenges.

Abstract: In 1637, Pierre de Fermat asserted that the equation aⁿ + bⁿ = cⁿ has no positive integer solutions for any exponent n > 2, famously claiming to possess a proof too large for the margin. Although Andrew Wiles established the full theorem in 1994 using deep methods from algebraic geometry and modular forms, the possibility of a more elementary argument has remained a topic of enduring interest. In this work we give a classical proof of the nonexistence of solutions to the Fermat equation for prime exponents under a natural local constraint: we assume that for an odd prime p, any hypothetical primitive solution triple (a, b, c) to a^p + b^p = c^p satisfies a + b − c < 2p. The proof proceeds by establishing that the difference δ = a + b − c must satisfy δ ≥ 2p, thereby contradicting the hypothesis. This follows from three elementary observations: first, by the binomial theorem, (a + b)^p > a^p + b^p = c^p, ensuring δ > 0; second, by Fermat’s Little Theorem applied modulo p, we have p | δ, yielding δ ≥ p; third, parity considerations force 2 | δ, which combined with δ ≥ p gives δ ≥ 2p. The argument relies solely on elementary number theory and congruence techniques, remaining close to the arithmetic framework available in Fermat’s time.

Abstract: The N88S mutation in human seipin causes a dominant motor neuron disease marked by ER stress and inclusion body formation, lipid imbalance, and oxidative damage. Yet the metabolic mechanisms connecting these defects remain poorly understood. Previous proteomic profiling revealed decreased protein levels of enzymes involved in the tricarboxylic acid cycle, fatty acid and carboxylic acid metabolism, and the glyoxylate cycle, suggesting impaired downstream utilization of peroxisome-derived acetyl-CoA. Guided by these findings, we investigated how peroxisomal function contributes to cellular dyshomeostasis. N88S seipin-expressing cells exhibited increased peroxisome abundance but defective routing of acetyl-CoA into mitochondrial and glyoxylate pathways, resulting in elevated reactive oxygen species (ROS), impaired glyoxylate cycle activation, and reduced metabolic adaptability to non-fermentable carbon sources. Loss of peroxisomes or forced cytosolic redirection of acetyl-CoA further exacerbated ER stress, ROS accumulation, lipid peroxidation, and the growth defect on N88S seipin-expressing cells, whereas inhibition of fatty acid synthesis mitigated oxidative damage. These findings demonstrate that N88S seipin triggers a futile cycle in which misrouted cytosolic acetyl-CoA drives lipogenesis, amplifying oxidative damage and ER stress. We conclude that defective peroxisome-mitochondria metabolic coupling and acetyl-CoA misrouting may represent central pathogenic mechanisms driving cellular dysfunction in N88S-linked seipinopathy.

Abstract:

Background: While Plasmodium falciparum (Pf) genomes are constantly evolving to counter new antimalarial drugs, Pf parasites currently allow ancient Pf-malaria-combating red blood cell (RBC) genetic variants to markedly protect humans against onset of severe Pf disease and death. The prevalences of sickle-trait hemoglobin (HbAS) RBCs and “dual-gene protection” type-O HbAS RBCs are substantial in Pf-endemic regions thousands of years after the “sickle” HbS hemoglobin allele (HBB gene variant) and the type-O ABO blood group first emerged. Do Pf-human coevolution data and growing interest in transfusion services in Africa suggest rescue exchanges of “evolution-engineered” RBCs warrant evaluation? Methods: We reviewed transfusion-related publications and data regarding Pf-combating RBC genetic variants and a worrisome Pf genotype (Pfsa+++) that completely eliminates HbAS survival-promotion. Results: Clinicians in Africa are eager to advance transfusion therapies and exploit automated continuous-flow apheresis machines for RBC exchange. There is no evidence the low prevalence of Pfsa+++ is increasing or the combination of the survival-promoting effects of HbAS hemoglobin and type-O blood group provides less than an additive increase in protection. Conclusions: Geneticists can support evaluating therapeutic use of HbAS RBCs by explaining how the prevalence of the worrisome Pfsa+++ genotype might be low and unchanging due to an equilibrium between competing selection pressures and “fitness costs.” Since HbAS hemoglobin alone provides 90% protection against death, conceivably, no human with type-O HbAS RBCs has ever died from Pf malaria. So, it seems prudent to evaluate converting children with life-threatening Pf infections into type-O HbAS patients via exchange transfusion – now.

Abstract: Subalpine grasslands represent highly sensitive ecosystems that are increasingly exposed to climate extremes, yet their long-term disturbance dynamics remain poorly documented. This study investigates climate-driven dieback of subalpine grasslands in Central Europe using a harmonized, multi-decadal satellite time series. We analyzed Landsat (TM, ETM+, OLI, OLI-2) and Sentinel-2 imagery spanning 1984–2024 to detect changes in grassland condition, supported by field-based validation, climatic indices, and geomorphological analysis. Several spectral indices related to non-photosynthetic vegetation were evaluated, with the Normalized Burn Ratio (NBR) showing the highest ability to discriminate dead grassland biomass from live vegetation. Retrospective mapping revealed four distinct dieback events since 2000, comprising two short-term episodes with rapid within-season recovery and two long-term events characterized by persistent degradation and slow regeneration. Dieback timing corresponded closely with climatic extremes, particularly droughts of varying duration, while winter frost under shallow soil conditions likely contributed to long-term damage in some cases. Geomorphological analysis indicated that wind exposure, elevation, and terrain convexity strongly modulate dieback susceptibility, highlighting the importance of fine-scale environmental controls. Our results demonstrate the value of long-term, multi-sensor satellite observations for detecting and interpreting climate-driven disturbances in subalpine grasslands and provide a transferable framework to support monitoring and conservation of mountain ecosystems under ongoing climate change.

Abstract:

Digital transformation in public institutions is increasingly understood as a socio-technical and organizational process rather than a purely technological upgrade. This study presents the design of an ICT-based digital transformation roadmap aimed at improving administrative efficiency and citizen service delivery in a municipal public utility in Ecuador. A mixed-methods diagnostic approach was adopted, combining qualitative evidence from direct observation and a semi-structured interview with the head of the IT department, and quantitative data from a structured online survey administered to citizens. Baseline Key Performance Indicators (KPIs) were established using institutional records, service logs, and workflow analysis conducted over a three-month diagnostic window. Post-implementation KPI values are explicitly treated as {ex ante} projections, derived from process redesign analysis, benchmarking with comparable public utilities, and scenario-based assumptions, rather than empirically observed outcomes. The empirical results demonstrate high citizen readiness and acceptance of proposed digital services, including remote service portals, electronic invoicing, and automated support channels. The projected operational improvements—such as reductions in response and administrative processing times and increased digital transaction rates—are therefore presented as expected performance scenarios. A risk and alternative scenario analysis further examines how organizational constraints, resource availability, governance capacity, and change-management factors may moderate these outcomes. The study contributes a transparent and replicable framework for diagnosing digital readiness and planning ICT-driven transformation initiatives in resource-constrained public utilities, while emphasizing the need for future longitudinal validation using post-implementation data.

Abstract: This study examined the knowledge of journalists in the newsroom to determine what they know, what they do, and how they could improve their reporting of climate change in Nigeria. The study population included 15,000 registered members of the Nigeria Union of Journalists (NUJ) from 37 councils (chapters). It was a mixed method that employed both quantitative and qualitative data. The sample size was 403. A purposive sampling procedure was applied while gathering data from the respondents via the Internet. It was found that journalists in Nigeria do not have sufficient knowledge of critical issues around climate change, such as mitigation and adaptation strategies. The study also found that only 14% of journalists regularly report climate change issues. This study concludes that professional deficiency was the reason why the majority of journalists do not report on climate change. It recommended training, retraining, and exposure to awards and other opportunities to encourage journalists to report climate change frequently.

Abstract: Background: Over the last two decades, there has been a substantial change in the understanding of post-traumatic hypopituitarism which is no longer regarded as a marginal phenomenon. Clinical manifestations of pituitary hormone deficiency are frequently nonspecific, with fatigue and cognitive dysfunction predominating. Given that head injuries currently constitute a global burden for healthcare systems, the aim of the present study was to determine whether self-reported post-mTBI symptoms that may indicate hypopituitarism reflect true pituitary insufficiency or are attributable to other hormonal aberrations. Objective: Assessment of the relationship between self-reported symptoms of post-traumatic hypopituitarism and hormonal test results following mild Traumatic Brain Injury (mTBI). Setting: Patients were recruited from a tertiary trauma center emergency department (ED) in northern Poland from January 2023 to October 2025. Participants: Adult (18>y.o.) individuals with mTBI meeting the inclusion criteria. Design: Prospective cohort study. During their post-head injury admission to the ED patients had a blood sample taken. The procedure was repeated consecutively after 3,6 and 12 months. After 6 and 12 months, patients were asked to complete a questionnaire. Method: Pituitary and thyroid hormones were measured using Chemiluminescence Immunoassay method (CLIA) and Heterogenous immunochemiluminescence method (CMIA). The questionnaire used was designed for the purposes of this study Questionnaire for the Assessment of Symptoms of Anterior Pituitary Insufficiency in Patients After Mild Traumatic Brain Injury (mTBI) Hospitalized in the Emergency Department. Results: Self-reported symptoms suggestive of anterior pituitary dysfunction following mTBI were not confirmed by laboratory assessment of pituitary hormones. However, after 6 months, a statistically significant correlation was found between the number of reported symptoms and prolactin levels (ρ = 0.730; p = 0.0013), whereas after 12 months a downward trend in fT3 levels was observed compared with baseline. Conclusion: Persistent symptoms observed in patients after mTBI at 6 and 12 months, particularly those related to increased fatigue and impaired concentration, appear to be associated primarily with prolactin levels (6-month observation) and with a decrease in fT3 levels (12-month observation) rather than true post-traumatic hypopituitarism (PTHP).

Abstract: Peritoneal membrane–related technical failure remains a major limitation of peritoneal dialysis (PD), yet simple predictive biomarkers are lacking. The uric acid–to–HDL cholesterol ratio (UHR) is an integrative marker of metabolic-inflammatory burden. This retrospective cohort study included 214 adult patients who initiated PD between 1997-2025 at a tertiary center. Baseline UHR was calculated from laboratory measurements obtained within three months after PD initiation. The primary outcome was peritoneal membrane–related technical failure, defined as permanent transfer to hemodialysis due to ultrafiltration failure, inadequate solute clearance, or progressive membrane dysfunction. Among 214 patients, 62 (29%) developed membrane failure during follow-up. A UHR cut-off value of 14 was identified by ROC analysis (AUC 0.644). In multivariable Cox regression, UHR &gt;14 was independently associated with increased risk of membrane failure (HR 1.836, 95% CI 1.040–3.241, p = 0.036). A history of kidney transplantation prior to PD initiation also emerged as a strong independent predictor (HR 3.971, 95% CI 1.668–9.455, p = 0.002). Elevated baseline UHR is independently associated with peritoneal membrane–related technical failure. As a simple, inexpensive, and routinely available biomarker, UHR may support early risk stratification and individualized management in PD patients.

Abstract: Background: Drug development is one of the most complex, costly, and prolonged processes in biomedical sciences, yet comprehensive reviews integrating quantitative attrition data across all phases with global equity perspectives remain scarce. Objective: To provide a comprehensive scientific review of the pharmaceutical drug lifecycle during the Research and Development (R&D) phase, from initial discovery through Phase III clinical trials, analyzing success rates, timelines, costs, and disparities between developed and developing countries. Methods: A narrative review was conducted synthesizing evidence from peer-reviewed literature, regulatory agency reports, and published systematic reviews. Sources were identified through PubMed, Scopus, and Web of Science databases, with selection criteria emphasizing quantitative data on attrition rates, development timelines, costs, and geographic disparities in pharmaceutical R&D. Results: The complete drug development process typically requires 10–15 years, with costs ranging from $897 million to $1.9 billion per approved drug. Only 9.6–21.5% of compounds entering clinical trials achieve regulatory approval. Preclinical attrition reaches 95%, with Phase I-to-II progression at 50%, Phase II-to-III at 34%, and Phase III-to-approval at 52%. Lack of efficacy accounts for 56% of Phase II/III failures, followed by safety concerns (28%). Therapeutic area variability is substantial: Alzheimer's disease shows a 0.4% success rate versus 21.5% overall. Critical disparities exist between developed and developing countries in R&D capacity, regulatory infrastructure, and disease priorities, with clinical trials in emerging markets costing up to 60% less but raising ethical and quality standards challenges. Conclusions: Drug development efficiency remains a critical challenge for global health. Improving preclinical predictability, adopting biomarker-driven patient selection, implementing adaptive trial designs, and addressing global R&D inequities through innovative financing mechanisms represent key strategies to improve development efficiency and health equity. Future research should focus on generating systematic data from low- and middle-income countries to better characterize and address global pharmaceutical R&D disparities.

Abstract: Urban green space (UGS) is a critical component of sustainable cities and a modifiable determinant of mental health (MH). This review synthesizes 113 empirical studies and 929 bibliometric records to map theoretical advances, methodological evolution, and governance implications in the UGS–MH field. We integrate six validated pathways into a unified socio-ecological framework, including attention restoration, stress recovery, behavioral activation, physiological regulation, social cohesion, and environmental buffering. Methodological trends indicate a shift from static greenness proxies to street view and multimodal exposure measures, and from cross sectional correlations to models that address spatial heterogeneity, causal identification, and AI enabled prediction. Bibliometric mapping shows increasing interdisciplinarity, geographic diversification, and a growing focus on dynamic exposure science. Persistent challenges include exposure outcome spatial and temporal misalignment, reliance on single modality indicators, limited causal inference, and constrained cross cultural generalizability. Building on these insights, we propose a governance oriented framework to support sustainable and healthy cities through equitable green access, behavior informed planning, nature based interventions, and data driven decision support. Overall, this review strengthens the evidence to action bridge at the interface of urban sustainability and population mental health.

Abstract: This study investigates ice crystal sedimentation calculation errors arising from three-moment bulk cloud scheme. Both offline tests and one-dimensional cloud model simulations indicate that sedimentation calculation errors are most pronounced at both the cloud bottom and cloud top. At the cloud bottom, the error stems from how the bulk method treats ice crystal sedimentation. Specifically, the method uses three weighted fall velocities (corresponding to the three moments) to represent instantaneous fluxes through a fixed altitude, which inherently assumes that falling ice crystals can only affect the adjacent model layer below. This assumption artificially constrains the falling distance of larger ice crystals. At the cloud top, the differences among these three weighted fall velocities can give rise to physical inconsistencies. This issue is handled by artificial adjustment, which leads to a spurious narrow size distribution shape of ice crystals, especially under model configurations with coarse temporal resolution (large dT) and fine vertical resolution (small dH). If only the sedimentation process is considered, the above calculation errors can be effectively minimized by lowering the dT/dH ratio.