Methodological Limitations Research Articles

Influence of social media on maternal decision-making and breastfeeding practices

Breastfeeding practices are influenced by multifactorial determinants including individual characteristics, external support systems, and media influences. This commentary emphasizes such complex factors influencing breastfeeding practices. Potential methodological limitations and the need for diverse sampling in studying breastfeeding practices are highlighted. Further research must explore the interplay between social influences, cultural norms, government policies, and individual factors in shaping maternal breastfeeding decisions.

Investigating the acute cognitive effects of dietary compounds using fNIRS: methodological limitations and perspectives for research targeting healthy adults

Investigating the acute cognitive effects of dietary compounds using fNIRS: methodological limitations and perspectives for research targeting healthy adults

Leveraging Mendelian randomization to inform drug discovery and development for ischemic stroke.

Discovery and development of efficacious and safe pharmacological therapies is fraught with challenges. As proteins constitute the majority of drug targets and are encoded by genes, naturally occurring genetic variation within populations can provide valuable insights to inform drug discovery and development efforts. The drug target Mendelian randomization (MR) paradigm leverages these principles to investigate the causal effects of drug targets in humans. This review examines the application of drug target MR in informing the efficacy and development of therapeutics for ischemic stroke prevention and treatment. We consider applications of MR for existing and novel treatment strategies, including targeting blood pressure, lipid metabolism, coagulation, inflammation and glycemic control. Several of these genetically supported targets are under evaluation in late-stage clinical trials. Methodological limitations of drug target MR are addressed, followed by an outline of future research directions. We anticipate that careful application of drug target MR will enhance the efficiency of drug development for ischemic stroke, consequently accelerating the delivery of effective medications to patients.

Enhancing Paediatric and Strabismus Ophthalmology Departments in Spain Through the Inclusion of Orthoptists: Insights from a Nationwide Survey

Background and objectives: The absence of the orthoptic profession in Spain contrasts with its value and recognition in other countries. This study aimed to gauge Spanish ophthalmologists’ interest in including and promoting orthoptists in paediatric and strabismus departments. Secondary objectives included assessing interest in requesting orthoptists, involvement in their training, and aligning their competencies with European standards. Methodology: Participants were recruited via WhatsApp and flyers during the 30th SEEOP Congress in May 2023 and invited to review a report on orthoptists’ significance followed by completing a 12-question online survey. Profile questions were asked via multiple-choice options. Opinions on integrating orthoptists to enhance care quality, training involvement, and alignment with European standards were rated using a Likert scale. Open-ended questions captured themes, and comments. Results: Forty-two paediatric and strabismologists in Spain participated, mostly hospital-employed with advanced degrees, 90% supported integrating orthoptists into their teams, with 83% interested in having them in their workplace. Nearly 90% believed that collaboration between ophthalmologists and orthoptists would improve care quality and reduce waiting lists, and 83% supported promoting this within national medical organisations. Additionally, 90% advocated level 4 advanced European-standard training for orthoptists and 25% were neutral about participating in training orthoptists. Participants emphasised the importance of qualified orthoptists for treating eye movement abnormalities, distinguishing them from other eye healthcare professionals and advocating for collaboration rather than replacement. Conclusions: This initial survey of paediatric ophthalmologists and strabismologists in Spain highlights support for orthoptists as allied health professionals, though garnering support for their training could be challenging. These conclusions should be considered in light of methodological, sample size, and resource limitations. The survey serves as a pilot for the future, suggesting improvements to explore the feasibility of introducing orthoptists in Spain.

Exploring foreign language classroom emotions and their impact on achievement in China: Validating the Achievement Emotions Questionnaire—Short form

Achievement emotions are crucial for acqussiring a foreign language, yet reliable tools to measure emotions beyond anxiety, enjoyment, and boredom in foreign language classrooms remain scarce. Furthermore, few studies have examined the different predictive effects of various foreign language classroom emotions on language learning achievement. This article presents two studies that aim to address these research gaps. In Study 1, based on the control-value theory of achievement emotions, we adapted and validated the short form of the Achievement Emotions Questionnaire for Foreign Language Classrooms, a self-report instrument that measures eight achievement emotions: enjoyment, hope, pride, anger, anxiety, boredom, hopelessness, and shame. The questionnaire was administered to 1,063 Chinese university students (567 females, mean age = 18.86, SD = 1.04, range = 17‒24 years) enrolled in English as a foreign language courses. The questionnaire exhibited acceptable psychometric properties including construct validity, reliability, measurement invariance, and external validity. In Study 2, we measured students’ English language learning achievement using their scores on a standardized exam. Scores of 202 students were analysed (131 females; mean age = 18.82, SD = 0.82, range = 17‒24 years). Regression analyses indicated that negative emotions were more predictive of achievement than positive emotions (except hope, which was the most influential predictor among the positive emotions). Theoretical, methodological, and practical implications and limitations were discussed.

Investigating droplet emission during speech interaction

AbstractConversations (normal speech) or professional interactions (e.g. projected speech in the classroom) have been identified as situations which increase individuals’ risk of exposure to respiratory viruses (including SARS-CoV-2) due to the high production of potentially infectious droplets. The few studies addressing this topic contain several methodological and linguistic limitations. This paper describes and validates an original combination of various methods, aimed at providing a global understanding of the complex physiological mechanisms underlying droplet emission during speech production. Twenty-one French speakers produced pseudowords and sentences under different phonetic conditions (e.g. loud vs normal intensity). In Experiment 1, we measured the airflow volume and airflow velocity exhaled from the mouth during speech. In Experiment 2, we measured the airflow velocity exhaled from different positions in the space around the mouth. In Experiment 3, we measured the number and size of expelled droplets. In all experiments, participants were asked to produce pseudowords and sentences under different phonetic conditions in an interactive setting. To validate our methodology, we tested the impact of voice intensity on the physiological measurements. We found that pseudowords and sentences spoken with loud intensity generated increased airflow volume and velocity compared to those spoken with normal intensity. Additionally, the number of droplets was higher for pseudowords spoken with loud intensity compared to normal intensity. From a methodological point of view, our study went beyond previous research by using multiple measures characterising droplet emission during speech. Furthermore, we applied an innovative experimental design, considering droplet emission in an interactive linguistic setting.

A bibliometric deep-dive: uncovering key trends, emerging innovations, and future pathways in sustainable employability research from 2014 to 2024

Sustainable employability refers to an individual’s ability to work and maintain employment over a long-term period. Despite significant progress in current research on sustainable employability, improvements are needed in areas such as consistency in definition, research on specific populations, industry-specific challenges, and methodological limitations. The current bibliometric analysis aims to address these areas by systematically studying published articles on sustainable employability from 2014 to 2024. A total of 170 articles on sustainable employability were retrieved from January 2014 to January 2024 using the Web of Science database. Various bibliometric information was collected, including the number of publications, keywords, countries of origin, journal names, research hotspots, national cooperation, and journal citation data. The Netherlands published the highest number of papers on sustainable employability. Additionally, sustainable employability has remained a research hotspot over the past decade. The complexity and multidimensionality of this field highlights the increasing focus on employees’ psychological characteristics, work environment, and health management, emphasizing the importance of interdisciplinary collaboration in research.

The BDNF-Interactive Model for Sustainable Hippocampal Neurogenesis in Humans: Synergistic Effects of Environmentally-Mediated Physical Activity, Cognitive Stimulation, and Mindfulness

This paper bridges critical gaps through proposing a novel, environmentally mediated brain-derived neurotrophic factor (BDNF)-interactive model that promises to sustain adult hippocampal neurogenesis in humans. It explains how three environmental enrichment mechanisms (physical activity, cognitive stimulation, and mindfulness) can integratively regulate BDNF and other growth factors and neurotransmitters to support neurogenesis at various stages, and how those mechanisms can be promoted by the physical environment. The approach enables the isolation of specific environmental factors and their molecular effects to promote sustainable BDNF regulation by testing the environment’s ability to increase BDNF immediately or shortly before it is consumed for muscle repair or brain update. This model offers a novel, feasible method to research environment enrichment and neurogenesis dynamics in real-world human contexts at the immediate molecular level, overcoming the confounds of complex environment settings and challenges of long-term exposure and structural plasticity changes. The model promises to advance understanding of environmental influences on the hippocampus to enhance brain health and cognition. This work bridges fundamental gaps in methodology and knowledge to facilitate more research on the enrichment–neuroplasticity interplay for humans without methodological limitations.

Limits of a single surrogate model development methodology to represent housing stocks

Surrogate models for predicting housing stock thermal comfort, and operational cost, energy or emissions have increasingly gained popularity due to the potential to identify solutions to accelerate and optimise construction. In addition to the potential opportunity to progress towards climate goals and increase resource efficiencies by identifying areas of interest, they are much less time consuming than brute-force simulations of millions of scenarios. Although they are popular due to their promise, analysis of scalability limits for surrogate model development methodologies have been left out. Without this analysis, assurance that these may be used over differing housing stock scales cannot be provided. This work uses black-box model interpretation as well as common predictive performance metrics to assess the scalability of the development methodology presented.The novelty of this work stems from its comparison of the performance of a development methodology through training a learning algorithm with a progressively varied dataset to illustrate its scalability. This validates the use of a single surrogate model to represent numerous bottom-up archetypes used to represent a housing stock.

A Study on the Antecedent Grouping Pattern of ESG Decoupling in New Energy Vehicle Manufacturing Companies

This study explores the decoupling phenomenon of listed companies in the new energy vehicle manufacturing category in terms of ESG (environmental, social, and corporate governance) by using fuzzy set qualitative comparative analysis (fsQCA) and necessity condition analysis (NCA) methods, and identifies four different groupings. These groupings reveal the complexity and diversity of firms' ESG performance and disclosure, including high gearing and low environmental commitment, high management compensation and low social responsibility, high media attention and selective disclosure, and high market competition and inadequate governance. The results of the study show that financial pressure, management incentives, media attention and market competition all significantly affect firms' ESG behavior. Based on this, policy and management recommendations are proposed, such as strengthening the regulation of ESG disclosure, incorporating ESG performance assessment in executive incentives, and balancing short-term financial goals with long-term sustainable development. Although this study reveals the complexity of ESG decoupling in new energy automobile manufacturing firms, the limitations of data source, sample scope and methodology still exist. Future research should expand the sample scope, conduct dynamic analysis, and synthesize multiple methods to deepen the understanding of corporate ESG decoupling behavior and provide scientific guidance for management and policy making.

A SHACL-Based Approach for Enhancing Automated Compliance Checking with RDF Data

Automated Compliance Checking (ACC) has emerged as a critical tool for enforcing legal regulations across various domains. This paper contributes to ongoing research in Semantic Web technologies, particularly focusing on the execution of SHACL-SPARQL rules on RDF data. The RDF, being one of the most widely used knowledge representation (KR) formats, serves as the foundation of our approach, ensuring compatibility with existing standards and enhancing interoperability. Our research enhances the aggregate and temporal aspects of ACC by addressing the limitations of traditional ACC methodologies, which often fall short in managing the nuanced temporal and aggregate requirements essential for legal reasoning. Through a case study analysis of selected regulations with aggregate and temporal facets in LI 2204, which regulates local content and participation in Ghana’s upstream petroleum industry, this paper demonstrates the effectiveness of the proposed solution in achieving these dimensions of ACC. The findings underscore the potential of Semantic Web technologies to transform ACC practices by moving towards standardized, interoperable solutions. All source codes are freely available online together with instructions to locally reproduce the simulations.

Targeted Variant Assessments of Human Endogenous Retroviral Regions in Whole Genome Sequencing Data Reveal Retroviral Variants Associated with Papillary Thyroid Cancer

Papillary thyroid cancer (PTC) is one of the fastest-growing cancers worldwide, lacking established causal factors or validated early diagnostics. Human endogenous retroviruses (HERVs), comprising 8% of human genomes, have potential as PTC biomarkers due to their comparably high baseline expression in healthy thyroid tissues, indicating homeostatic roles. However, HERV regions are often overlooked in genome-wide association studies because of their highly repetitive nature, low sequence coverage, and decreased sequencing quality. Using targeted whole-genome sequence analysis in conjunction with high sequencing depth to overcome methodological limitations, we identified associations of specific HERV variants with PTC. Analyzing WGS data from 138 patients with PTC generated through The Cancer Genome Atlas project and 2015 control samples from the 1000 Genomes Project, we examined the mutational variation in HERVs within a 20 kb radius of known cancer predisposition genes (CPGs) differentially expressed in PTC. We discovered 15 common and 13 rare germline HERV variants near or within 20 CPGs that distinguish patients with PTC from healthy controls. We identified intragenic–intronic HERV variants within RYR2, LRP1B, FN1, MET, TCRVB, UNC5D, TRPM3, CNTN5, CD70, RYR1, RUNX1, CRLF2, and PCDH1X, and three variants downstream of SERPINA1 and RUNX1T1. Sanger sequencing analyses of 20 thyroid and 5 non-thyroid cancer cell lines confirmed associations with PTC, particularly for MSTA HERV-L variant rs200077102 within the FN1 gene and HERV-L MLT1A LTR variant rs78588384 within the CNTN5 gene. Variant rs78588384, in particular, was shown in our analyses to be located within a POL2 binding site regulating an alternative transcript of CNTN5. In addition, we identified 16 variants that modified the poly(A) region in Alu elements, potentially altering the potential to retrotranspose. In conclusion, this study serves as a proof-of-concept for targeted variant analysis of HERV regions and establishes a basis for further exploration of HERVs in thyroid cancer development.

Avatar Intervention in Virtual Reality for Cannabis Use Disorder in Individuals With Severe Mental Disorders: Results From a 1-Year, Single-Arm Clinical Trial.

The dual diagnosis of cannabis use disorder (CUD) and severe mental disorder (SMD) results in clinically complex individuals. Cannabis use is known to have negative consequences on psychiatric symptoms, medication compliance, and disease prognosis. Moreover, the effectiveness of currently available psychotherapeutic treatments is limited in this population. In this context, our research team developed avatar intervention, an approach using virtual reality as a therapeutic tool to treat CUD in individuals with SMD. This pilot clinical trial aimed to evaluate, until the 1-year follow-up, the efficacy of avatar intervention for CUD among 32 participants with a dual diagnosis of SMD and CUD. Over the course of the 8 intervention sessions, participants were given the opportunity to enter a dialogue in virtual reality with an avatar representing a person with a significant role in their consumption, who was animated in real time by a therapist. The primary outcomes were the quantity of cannabis consumed and the frequency of use. Secondary outcomes included severity of problematic cannabis use, motivation for change, protective strategies for cannabis use, consequences of cannabis use, psychiatric symptoms, and quality of life. Changes in reported outcomes during the assessment periods before the intervention; postintervention; and 3, 6, and 12 months after the end of the intervention were assessed using a linear mixed-effects model. Significant reductions were observed in the quantity of cannabis consumed, and these were maintained until the 12-month follow-up visit (d=0.804; P<.001; confirmed by urine quantification). Frequency of cannabis use showed a small significant reduction at the 3-month follow-up (d=0.384; P=.03). Moreover, improvements were observed in the severity of CUD, cannabis-related negative consequences, the motivation to change cannabis use, and the strategies used to mitigate harms related to cannabis use. Finally, moderate benefits were observed for quality of life and psychiatric symptoms. Overall, this unique intervention shows promising results that seem to be maintained up to 12 months after the end of the intervention. With the aim of overcoming the methodological limitations of a pilot study, a single-blind randomized controlled trial is currently underway to compare the avatar intervention for CUD with a conventional addiction intervention.

Sexually dimorphic response to tobacco in the development of chronic kidney disease: a systematic review

IntroductionChronic kidney disease (CKD) demonstrates a complex interaction with tobacco exposure and sex differences, where females and males may experience varying risks and outcomes. This study aims to investigate how sex differences mediate the relationship between tobacco exposure and CKD development, with a secondary focus on regional variability and social determinants of health.Study selection and criteriaComprehensive searches on MEDLINE, EMBASE, clinicaltrials.gov, and MedRxiv until October 6, 2022, were conducted. Eligibility criteria involved any study that reported primary data on the prevalence of CKD, with information pertaining to both sex and tobacco exposure.Data extractionData retrieved include patient socio-demographic characteristics, general study information, diagnostic methods, social determinants of health, and the cause of CKD (e.g., tobacco-related or non-tobacco-related).ResultsStudies were selected through a comprehensive search using key terms such as "chronic kidney disease," "smoking," and "sex differences," which identified 3,025 articles, of which 28 were selected for full texts after screening titles, abstracts. Among the 28 included studies, smoking was consistently identified as a significant risk factor for CKD, with notable disparities related to sex, socioeconomic status, race, and urban versus rural settings. Significant geographical variability in CKD prevalence was observed, ranging from 2.5% to 68.1%, with the highest prevalence in Asia. However, due to high heterogeneity and methodological limitations, a meta-analysis of CKD prevalence stratified by sex and tobacco exposure was not feasible.ConclusionsThe findings emphasize the need for further research to comprehend the intricate relationship between, tobacco exposure, sex, and CKD management, as well as the consideration of cultural, geographical, socioeconomic, political, and structural factors when understanding the pathophysiology and management of CKD.

Mainstreaming Law and Human Rights Education in Indonesia: How the National Training Institute Can Drive Legal and Policy Reform?

This paper explores the integration of law and human rights education in Indonesia, with a focus on the role of the National Training Institute (NTI) in advancing these principles through governmental and public service training programs. As Indonesia continues its commitment to upholding human rights, both domestically and in line with international conventions, the mainstreaming of law and human rights education plays a critical role in promoting justice, equality, and legal literacy across society. Despite legal frameworks aimed at protecting human rights, there remains a significant gap in the effective implementation of such education, particularly within public institutions and civil service training. The study assesses how the NTI has integrated law and human rights topics into its curricula, examining the effectiveness of these programs in building awareness and understanding of legal rights and responsibilities. Drawing from interviews with trainers and participants, the paper identifies both strengths and limitations of current training methodologies, highlighting the challenges of addressing complex human rights issues in a culturally diverse context. Furthermore, the research underscores the importance of law and policy reform in advancing human rights education. It argues that a comprehensive and systematic approach to training in legal rights is not only crucial for improving compliance with national and international human rights standards but is also integral to broader legal reforms aimed at enhancing public participation and accountability in governance. The paper concludes by proposing recommendations for strengthening law and human rights education within the NTI framework, advocating for reforms that expand its reach and effectiveness as a tool for both societal change and legal empowerment.

Quantification of volcanic degassing and analysis of uncertainties using numerical modeling: the case of Stephanos crater (Nisyros Island, Greece)

Nisyros Island (Greece) is affected by widespread gas emissions from fumarolic fields located at the bottom of hydrothermal craters in the southern part of its caldera. This morphology and the current low gas fluxes make Nisyros an ideal site for testing the limits of physics-based gas dispersal models in confined and low-emission conditions. Here, we focused our attention on the local scale volcanic gas dispersion from the Stephanos hydrothermal crater. In April 2023, a 1-week survey was carried out to measure weather data, CO2 and H2S gas fluxes, air concentrations from portable gas stations, and chemical composition of fumarolic gases and to acquire thermal images of the crater floor. These data were used as inputs and boundary conditions for numerical simulations using a DISGAS-2.6.0 model in order to quantify the present-day volcanic degassing and its associated uncertainties, accounting for the meteorological variability. Model results are provided in terms of H2S probabilistic exceedance and persistence maps, showing gas concentrations within the crater that fall below the thresholds indicated for the occurrence of serious respiratory problems. Since DISGAS-2.6.0 does not account for chemical reactions, this study represents a good opportunity to discuss the methodological limits of simulating the dispersion of H2S which is challenging due to its rapid degradation and dilution in the atmosphere. In this regard, we also provided an empirical law of the H2S depletion in low-emission conditions that takes into account the uncertainties related to the field measurements.

Propylthiouracil-induced vasculitis with alveolar hemorrhage after 31 years of treatment: a case report

BackgroundPropylthiouracil is an antithyroid medication that is associated with ANCA positivity, often in the absence of clinically overt vasculitis. Propylthiouracil-induced ANCA-associated vasculitis (AAV) is characterized by multiple antigenicity and presents similarly to other forms of drug-induced vasculitis.Case presentationWe report a case of a 49-year-old woman who developed propylthiouracil-induced AAV after 31 years of intermittent therapy. The patient presented with progressive respiratory and generalized symptoms. She was diagnosed with propylthiouracil-induced AAV with alveolar hemorrhage based on detection of ANCA and anti-MPO antibodies, exclusion of primary vasculitis, and symptom resolution following propylthiouracil withdrawal. The patient was treated with intravenous methylprednisolone, followed by oral prednisolone. Her symptoms resolved, and her laboratory and radiological tests improved within one week.ConclusionsResearch linking the duration of propylthiouracil use to the development of vasculitis is restricted by multiple methodological limitations. Maintaining a high index of clinical suspicion is a more reliable approach to detecting propylthiouracil-induced AAV than regular laboratory monitoring, given that patients with Graves’ disease may show ANCA positivity in the absence of medication use. Therefore, clinicians should remain vigilant for the varied presentations of propylthiouracil-induced AAV. Moreover, further research is recommended to investigate the possible link between the duration of PTU use and the onset of clinically overt vasculitis.

A reinvestigation of cognitive styles in sticklebacks: decision success varies with behavioral type

Abstract The ‘cognitive styles’ hypothesis suggests that individual differences in behavior are associated with variation in cognitive performance via underlying speed-accuracy trade-offs. While this is supported, in part, by a growing body of evidence, some studies did not find the expected relationships between behavioral type and cognitive performance. In some cases, this may reflect methodological limitations rather than the absence of a true relationship. The physical design of the testing arena and the number of choices offered in an assay can hinder our ability to detect inter-individual differences in cognitive performance. Here, we re-investigated the cognitive styles hypothesis in threespine stickleback (Gasterosteus aculeatus), adapting the maze design of a previous study which found no cost to decision success by faster (bolder) individuals. We used a similar design but increased the size of the maze and incorporated an additional choice in the form of a third maze arm. We found, in accordance with cognitive style expectations, that individuals that were consistently slower to emerge from the start chamber made fewer errors than fish that emerged faster. Activity in an open field test, however, did not show evidence of a relationship with decision success, possibly due to the low number of repeated observations per fish in this separate assay. Our results provide further empirical support for the cognitive styles hypothesis and highlight important methodological aspects to consider in studies of inter-individual differences in cognition.

Impact of Endocrine Disrupting Pesticide Use on Obesity: A Systematic Review

Background/Objectives: Endocrine disruptors are substances capable of altering the functions of the endocrine system. There is evidence that some pesticides can be endocrine disruptors and, among some of their effects, we find alterations in pubertal development and in the function of the thyroid gland, which could be related to a greater tendency of obesity. The aim was to evaluate the evidence from clinical and preclinical studies on the association between pesticides used in agriculture and found in plant-based foods with overweight/obesity. Methods: This is a systematic review of articles on the impact of the use of endocrine disrupting pesticides on obesity, conducted according to the PRISMA-2020 guidelines. Results: There was evidence that some pesticides, such as chlorpyrifos, pyrethroids, and neonicotinoids, may promote obesity and other anthropometric changes by altering lipid and glucose metabolism, modifying genes, or altering hormone levels such as leptin. Other studies suggest that perinatal exposure to chlorpyrifos or pesticides such as vinclozolin may alter lipid metabolism and promote weight gain in adulthood, whereas other pesticides such as boscalib, captan, thiacloprid, and ziram were not associated with changes in weight. Exposure to pesticides such as vinclozolin may be associated with a higher prevalence of overweight/obesity in later generations. Conclusions: The few studies that do not show these associations have methodological limitations in data collection with confounding variables. Further studies are needed to provide more and higher quality evidence to determine the true effect of these substances on obesity.

Diets to promote healthy brain ageing.

Diet is a modifiable lifestyle factor with a proven role in cardiovascular disease risk reduction that might also play an important part in cognitive health. Evidence from observational studies has linked certain healthy dietary patterns to cognitive benefits. However, clinical trials of diet interventions have demonstrated either null or, at best, small effects on cognitive outcomes. In this Review, we summarize the currently available evidence from observational epidemiology and clinical trials regarding the potential role of diet in theprevention of cognitive decline and dementia. We further discuss possible methodological limitations that might have hindered the ability of previous diet intervention trials to capture potential neuroprotective effects. Considering the overwhelming and continuously expanding societal, economic and health-care burden of Alzheimer disease and other dementias, future nutritional research must address past methodological challenges to accurately and reliably inform clinical practice guidelines and public health policies. Within this scope, we provide a roadmap for future diet intervention trials for dementia prevention. We discuss study designs involving both intensive personalized interventions - to evaluate pharmacokinetic and pharmacodynamic properties, establish neuroprotective thresholds, and test hypothesized biological mechanisms and effects on brain health and cognition through sensitive and precise biomarker measures - and large-scale, pragmatic public health interventions to study population-level benefits.