Hasil untuk "Arctic medicine. Tropical medicine"

Abolfazl Mohajer

We define and investigate the tropical Prym varieties associated to unramified Galois cyclic covers of tropical curves (or equivalently metric graphs) $\tildeΓ\to Γ$. Our approach here is to study the tropical Prym varieties using group actions on tropical abelian varieties induced by the cyclic Galois group of the cover of tropical curves. We also define and conider the Abel-Prym map for tropical cyclic covers extending that for double covers. As a special case we consider free $\Z_3$-covers of tropical curves and their associated tropical Prym variety and compute its volume generalizing the case of double covers.

Gabrielle Hoyer, Michelle W Tong, Rupsa Bhattacharjee et al.

Precision medicine in musculoskeletal imaging requires scalable measurement infrastructure. We developed a modular system that converts routine MRI into standardized quantitative biomarkers suitable for clinical decision support. Promptable foundation segmenters (SAM, SAM2, MedSAM) were fine-tuned across heterogeneous musculoskeletal datasets and coupled to automated detection for fully automatic prompting. Fine-tuned segmentations yielded clinically reliable measurements with high concordance to expert annotations across cartilage, bone, and soft tissue biomarkers. Using the same measurements, we demonstrate two applications: (i) a three-stage knee triage cascade that reduces verification workload while maintaining sensitivity, and (ii) 48-month landmark models that forecast knee replacement and incident osteoarthritis with favorable calibration and net benefit across clinically relevant thresholds. Our model-agnostic, open-source architecture enables independent validation and development. This work validates a pathway from automated measurement to clinical decision: reliable biomarkers drive both workload optimization today and patient risk stratification tomorrow, and the developed framework shows how foundation models can be operationalized within precision medicine systems.

Haoran Li, Xingye Cheng, Ziyang Huang et al.

Traditional Chinese Medicine diagnosis and treatment principles, established through centuries of trial-and-error clinical practice, directly maps patient-specific symptom patterns to personalised herbal therapies. These empirical holistic mapping principles offer valuable strategies to address remaining challenges of reductionism methodologies in modern biomedicine. However, the lack of a quantitative framework and molecular-level evidence has limited their interpretability and reliability. Here, we present an AI framework trained on ancient and classical TCM formula records to quantify the symptom pattern-herbal therapy mappings. Interestingly, we find that empirical TCM diagnosis and treatment are consistent with the encoding-decoding processes in the AI model. This enables us to construct an interpretable TCM embedding space (TCM-ES) using the model's quantitative representation of TCM principles. Validated through broad and extensive TCM patient data, the TCM-ES offers universal quantification of the TCM practice and therapeutic efficacy. We further map biomedical entities into the TCM-ES through correspondence alignment. We find that the principal directions of the TCM-ES are significantly associated with key biological functions (such as metabolism, immune, and homeostasis), and that the disease and herb embedding proximity aligns with their genetic relationships in the human protein interactome, which demonstrate the biological significance of TCM principles. Moreover, the TCM-ES uncovers latent disease relationships, and provides alternative metric to assess clinical efficacy for modern disease-drug pairs. Finally, we construct a comprehensive and integrative TCM knowledge graph, which predicts potential associations between diseases and targets, drugs, herbal compounds, and herbal therapies, providing TCM-informed opportunities for disease analysis and drug development.

Aliaksandr Marozau, Barbara Karpowicz, Tomasz Kowalewski et al.

Mixed Reality (MR) technologies such as Virtual and Augmented Reality (VR, AR) are well established in medical practice, enhancing diagnostics, treatment, and education. However, there are still some limitations and challenges that may be overcome thanks to the latest generations of equipment, software, and frameworks based on eXtended Reality (XR) by enabling immersive systems that support safer, more controlled environments for training and patient care. Our review highlights recent VR and AR applications in key areas of medicine. In medical education, these technologies provide realistic clinical simulations, improving skills and knowledge retention. In surgery, immersive tools enhance procedural precision with detailed anatomical visualizations. VR-based rehabilitation has shown effectiveness in restoring motor functions and balance, particularly for neurological patients. In mental health, VR has been successful in treating conditions like PTSD and phobias. Although VR and AR solutions are well established, there are still some important limitations, including high costs and limited tactile feedback, which may be overcome with implementing new technologies that may improve the effectiveness of immersive medical applications such as XR, psychophysiological feedback or integration of artificial intelligence (AI) for real-time data analysis and personalized healthcare and training.

Tianai Huang, Jiayuan Chen, Lu Lu et al.

Large language models (LLMs) have demonstrated exceptional capabilities in general domains, yet their application in highly specialized and culturally-rich fields like Traditional Chinese Medicine (TCM) requires rigorous and nuanced evaluation. Building upon prior foundational work such as TCM-3CEval, which highlighted systemic knowledge gaps and the importance of cultural-contextual alignment, we introduce TCM-5CEval, a more granular and comprehensive benchmark. TCM-5CEval is designed to assess LLMs across five critical dimensions: (1) Core Knowledge (TCM-Exam), (2) Classical Literacy (TCM-LitQA), (3) Clinical Decision-making (TCM-MRCD), (4) Chinese Materia Medica (TCM-CMM), and (5) Clinical Non-pharmacological Therapy (TCM-ClinNPT). We conducted a thorough evaluation of fifteen prominent LLMs, revealing significant performance disparities and identifying top-performing models like deepseek\_r1 and gemini\_2\_5\_pro. Our findings show that while models exhibit proficiency in recalling foundational knowledge, they struggle with the interpretative complexities of classical texts. Critically, permutation-based consistency testing reveals widespread fragilities in model inference. All evaluated models, including the highest-scoring ones, displayed a substantial performance degradation when faced with varied question option ordering, indicating a pervasive sensitivity to positional bias and a lack of robust understanding. TCM-5CEval not only provides a more detailed diagnostic tool for LLM capabilities in TCM but aldso exposes fundamental weaknesses in their reasoning stability. To promote further research and standardized comparison, TCM-5CEval has been uploaded to the Medbench platform, joining its predecessor in the "In-depth Challenge for Comprehensive TCM Abilities" special track.

Carmem Aliandra Freire de Sá, Daniele Melo Sardinha, Ricardo José de Paula Souza e Guimarães et al.

Abstract Background Prior to the pandemic, malaria showed a global downward trend due to control and surveillance efforts. The COVID-19 pandemic contributed to the disruption of progress in malaria control, leading to an increase in cases and deaths, particularly in Africa. In its bulletin, the World Health Organization (WHO) reported the interruption of essential activities, such as active case finding and mass treatment for diseases like malaria, during the pandemic. This resulted in a setback for disease control efforts, with the recovery of these activities projected by 2030. In Brazil, there are no studies on the impact of the pandemic on malaria transmission. For this reason, the study aims to assess the impacts of the COVID-19 pandemic on the disease’s transmission. Methods This is an observational, descriptive, and analytical study with a quantitative approach, which analysed secondary data of reported malaria cases in the state of Pará, Brazil, between 2018 and 2023. Data were obtained from Sivep-Malária (Malaria Epidemiological Surveillance Information System) and the Brazilian Ministry of Health’s COVID-19 database. For statistical analysis, the study period was divided into three periods: pre-pandemic (2018–2019), critical period (2020–2021), and less critical period (2022–2023). Comparisons of sociodemographic and occupational variables, parasite species, and case mobility between periods were tested using the Chi-square test. Results A total of 170,245 malaria cases were reported: 79,125 before the pandemic, 44,830 in the critical period, and 47,502 in the less critical period. Cases among miners increased from 17.2% to 58%. Plasmodium falciparum cases rose from 2.6% to 11.3%. Imported cases from other states accounted for 3813 (2.2%) of the cases. The peaks of autochthonous malaria cases in Pará occurred from August to November between 2018 and 2023. Conclusions The seasonality of the disease was observed to be maintained at levels similar to the pre-COVID-19 pandemic period. The reduction in the number of malaria cases during the critical period can be attributed to the control actions of the disease control programme in the state of Pará, while the increase was associated with the resumption of social interaction habits and greater internal mobility, facilitated by COVID-19 vaccination.

Ghulam Raza Mohammadyan, Seyed Aria Nejadghaderi, Hamid Sharifi et al.

Abstract Background Global vaccine coverage improved substantially. In Afghanistan, routine immunization has been expanding since 1978 but remains inadequate, contributing to consistently high under-five mortality rates. This time-trend analysis focused on national routine childhood immunization coverage and the number of Expanded Programme on Immunization (EPI) centers in Afghanistan from 1999 to 2023. Methods Data were drawn from World Health Organization/United Nations Children’s Fund (WHO/UNICEF) estimates and the "Gavi, the Vaccine Alliance" administrative reports (1999–2018). Seven vaccines were assessed: third dose of polio vaccine (Pol3), first and second doses of measles‐containing vaccine (MCV1, MCV2), first and third doses of diphtheria‐tetanus‐pertussis vaccine (DTP1, DTP3), Bacillus Calmette–Guérin (BCG), and third dose of hepatitis B vaccine (HepB3). Linear spline regression, with knots in 2006 and 2018, was validated. Results Between 1999 and 2023, coverage of all seven vaccines increased. WHO/UNICEF data showed Pol3 rising from 27% to 68%, MCV1 from 31% to 55%, DTP1 from 15.2% to 67%, DTP3 from 27% to 60%, and BCG from 38% to 68%, with MCV2 growing from 2% to 42% and HepB3 peaking at 67%. Spline regression revealed rapid growth from 1999 to 2006, slower increases from 2007 to 2018, and declines from 2019 to 2023. Gavi data mirrored these patterns, with DTP3 rising by 7.96% annually from 1999 to 2006 and DTP1 falling by 0.30% from 2007 to 2018. EPI centers expanded by 159.78 per year (2001–2006) and 74.12 (2007–2018). Conclusions Afghanistan’s immunization coverage increased substantially until 2006, grew more slowly from 2007 to 2018, and declined after 2019. These patterns highlight the vulnerability of routine immunization programs to contextual challenges and suggest that sustaining coverage will require continued strengthening of routine services, monitoring subnational disparities, and implementing conflict-sensitive strategies.

Jimin Liu, Jeremy Cheuk-Hin Leung, Wenshou Tian et al.

Shan et al. (2023) recently reported significant seasonal advances of intense tropical cyclones (TCs) in both the Northern Hemisphere (NH) and Southern Hemisphere (SH) since the 1980s, and emphasized the data insensitivity of this conclusion, based on the Advanced Dvorak Technique-Hurricane Satellite (ADT-HURSAT) and the International Best Track Archive for Climate Stewardship (IBTrACS) datasets. However, this conclusion contradicts our recent findings. Following the procedures outlined in Shan et al., our analysis reveals that the seasonal advancing trend of intense TCs does not pass the significance test in the SH. Meanwhile, for the NH, the trend is statistically significant only when using the ADT-HURSAT, but not when using the IBTrACS. These discrepancies may be due to flaws in the calculations performed by Shan et al. The above findings raise doubts about the reproducibility and validity of Shan et al.'s conclusions regarding the global seasonal advance of intense TCs. We argue that the reported seasonal advance of intense TCs since the 1980s is inconclusive, and further investigations are needed.

Jorge P. Rodríguez, Konstantin Klemm, Carlos M. Duarte et al.

The reduction in sea ice cover with Arctic warming facilitates the transit of ships through routes that are remarkably shorter than the traditional shipping routes. Automatic Identification System (AIS), ideally designed to avoid vessel collisions, transmits on vessel navigation information (currently 27 types of messages) such as name, position or speed, is a powerful data source to monitor the progress of Arctic shipping as the ice cover decreases. Based on the analysis of an online platform collecting shipping AIS data, we quantified the spatial distribution of shipping through the Arctic Ocean, its intensity and the temporal evolution, in relation to the area released by the sea ice area. Shipping through the Arctic Ocean is distributed spatially following a heavy-tailed distribution, implying heavy traffic through a limited Arctic area, with an exponent that depends on the vessel category. Fishing is the category with the largest spatial spread, with the width of shipping routes correlated with the proximal sea ice area. The time evolution of these routes is characterized by increasing extended periods of shipping activity through the year. AIS data offers valuable information on the activity of the international fleet worldwide. In the context of the new international agreements, it is a valuable source to monitor shipping, fishing and the potential impact in marine life among other aspects. Here we have focused on the Arctic shipping in recent years, which is rapidly growing, particularly around the Northeastern and Northwest Passage coastal routes, providing an opportunity for the design of shorter shipping routes and reduced greenhouse gas emissions from transport of goods, but at a risk of impacts on the Arctic ecosystem.

Hainau Iddrisu, Emmanuel Ayitey Tagoe, Harriet Affran Bonful

Abstract Background Malaria in pregnancy (MiP) is a public health concern especially for pregnant women living in slums. The World Health Organization recommends at least three doses of Sulfadoxine-Pyrimethamine (SP) to prevent MiP. In Ghana, it is recommended that pregnant women receive a minimum of five doses of the medication. This study sought to determine the level of adherence to IPT5 policy and factors associated with adherence among pregnant women in a slum community in Ghana. Methods This was a cross-sectional study involving 232 nursing mothers and four healthcare workers at the St. Martin’s Memorial Hospital, Sukura, Ghana. Sociodemographic characteristics of nursing mothers were obtained using an interview-administered questionnaire. Data on the number of SP doses and other obstetrics characteristics were collected by reviewing the antenatal record books. To obtain information about healthcare and health system factors associated with adherence to the five-dose policy, four healthcare providers were interviewed. A data extraction form was used to obtain information about the availability of SP at the facility. Results The level of adherence to IPT5 was 8.6% (20/232) (95% CI 5.0–12.3) among the participants. Only 8.4% of the participants received their first dose at 16 weeks. Respondents who began ANC in the second trimester were 81% less likely to adhere to IPT5 than those who began in the first trimester (aOR = 0.19, 95% CI 90.01–0.65, p < 0.008). Healthcare provider and health system factors that influence IPT5 uptake include healthcare providers’ knowledge of IPTp-SP guidelines, the practice of Directly Observed Therapy, education of pregnant women, training of healthcare providers, and availability of water. SP was available at the facility during the period of review. Conclusion Adherence to the IPTp-SP five-dose policy was suboptimal. Pregnant women who started ANC early were more likely to adhere to the policy. Provider knowledge, DOT practice, training, education of pregnant women and water availability were also found to influence adherence. Encouraging early ANC visits and providing healthcare workers with necessary training can substantially improve adherence in slum areas.

Mohamed K. Mwanga, Silas Mirau, Jean M. Tchuenche et al.

Abstract Background Under-five mortality in Tanzania remains a persistent issue, significantly affecting both the health and economic sectors. Despite various interventions, the under-five mortality rate (U5MR) remains high, impeding progress toward global health targets. This study investigates the factors influencing under-five mortality in Tanzania, focusing on the gross domestic product (GDP), malaria incidence, access to water, and access to sanitation. Methods The study employed data sets for Tanzania U5MR, GDP, access to water and sanitation, and malaria incidences from the World Bank for the years 1960–2020. Missing values are generated through the linear trend at point method. To analyses the data, correlation analysis and Bayesian linear regression are employed. Results The analysis reveals significant relationships between the gross domestic product (GDP), malaria incidence, access to water, access to sanitation and under-five mortality. Furthermore, an increase in malaria incidences increase under-five mortality by 0.14 (14%), while access to water and sanitation exhibit an uncertain relationship. On the other hand, results show that an increase in the GDP lowers the likelihood of U5MR. Conclusion These findings underscore the importance of economic development and public health interventions in reducing the child mortality rate. The study provides valuable insights for policymakers aiming to achieve Sustainable Development Goal (SDG) Target 3.2 by 2030, which aims for all countries to accomplish U5MR of 25 or less deaths per 1000 live births. By highlighting the relationships between these variables, the study contributes practical evidence to support efforts towards SDG 3.2, emphasizing the need for targeted interventions in both health and infrastructure sectors.

Dee Jupp, Sherria Ayuandini, Frisca Tobing et al.

Abstract Background By 2022, the Government of Indonesia had successfully eliminated malaria in 389 out of 514 districts but continues to face a challenge in Eastern Indonesia where 95% of the total 2021 malaria cases were reported from Papua, West Papua and Nusa Tenggara Timur provinces. There is an increased recognition that malaria elimination will require a better understanding of the human behavioural factors hindering malaria prevention and treatment, informed by local context and local practice. Methods This research used a light-touch immersion research approach. Field researchers lived in communities over several days to gather data through informal conversations, group-based discussions using visual tools, participant observation and direct experience. The study was conducted in four high malaria endemic areas in Papua, West Papua, and Sumba Islands in Nusa Tenggara Timur. Results The research highlights how people’s perception of malaria has changed since the introduction of effective treatment which, in turn, has contributed to a casual attitude towards early testing and adherence to malaria treatment. It also confirms that people rarely accept there is a link between mosquitoes and malaria based on their experience but nevertheless take precautions against the annoyance of mosquitoes. There is widespread recognition that babies and small children, elderly and incomers are more likely to be seriously affected by malaria and separately, more troubled by mosquitoes than indigenous adult populations. This is primarily explained by acclimatization and strong immune systems among the latter. Conclusions Using immersion research enabled behaviour research within a naturalistic setting, which in turn enabled experiential-led analysis of findings and revealed previously unrecognized insights into attitudes towards malaria in Eastern Indonesia. The research provides explanations of people’s lack of motivation to consistently use bed nets, seek early diagnosis or complete courses of treatment. The felt concern for the wellbeing of vulnerable populations highlighted during light touch immersion provides an entry point for future social behaviour change communication interventions. Rather than trying to explain transmission to people who deny this connection, the research concludes that it may be better to focus separately on the two problems of malaria and mosquitoes (especially for vulnerable groups) thereby resonating with local people’s own experience and felt concerns.

Kelly Zongo, Kelly Zongo, Faraja Lyamuya et al.

Programs focused on elimination of lymphatic filariasis include the provision of surgery to address hydrocele, a complication of infection. Corrective surgical interventions are fully funded so that affected men in Tanzania can live normal and productive lives. Active case finding is used to identify candidates for hydrocele surgery. Oftentimes this results in men being identified as needing a hydrocelectomy when they actually have inguinal hernias. Given different funding streams, men with hernias do not have access to funded surgeries and are turned away during hydrocele surgical camps despite a clear need for surgical intervention; this poses an ethical dilemma. Also, hernias can occur in conjunction with hydroceles or be misdiagnosed as hydrocele. When misdiagnosis is identified during surgery, and there are no prior preparations to address both, complications can occur. Support from the private sector to complement NTD programs as a viable solution to providing hernia surgeries during hydrocelectomy camps has been used on a small scale in Tanzania and could be replicated on a larger scale.

Deeksha Adhikari, N. Rangra

More than 1300 species of the vast genus Acacia are found in tropical habitats. They are crucial economic plants since they produce traditional medicines, timber, and gum. The pharmacological uses of the Acacia genus include anti-diarrheal, anti-malarial, chronic pain relief, wound healing, anti-cancer, anti-rheumatism, and anti-diabetes activities. It is also used for treating various illnesses such as gastroenteritis, allergies, Alzheimer′s disease, cough, and cardiovascular disease. The present review aims to summarize the antimicrobial activities including the antibacterial and antifungal activity of the Acacia genus. The literature was searched in books and online databases including SciFinder, Google Scholar, Scopus, PubMed, and scientific journals using the most relevant keywords: Acacia+antimicrobial, Acacia+antibacterial, and Acacia+antifungal.

J. Meiring, P. Johnston

Several population-based studies have recently published data on the incidence of typhoid fever. 1 – 4 These studies redress gaps in our knowledge of disease burden in speci fi c locations and contribute to improved estimates of the global burden of typhoid fever. 5 These data are increasingly important to decision-makers in typhoid-endemic countries as they consider implementing typhoid conjugate vaccine (TCV) programs and apply for GAVI funding. 6 Although typhoid incidence estimates are informative, we should be cautious in generalizing their fi ndings beyond the period during which data were collected. Typhoid incidence is dynamic, with increases following the introduction of new strains with increased antimicrobial resistance, 7,8 and reductions following the introduction of disease control interventions. 9 Long-term incidence data from single-sites is rare, but can provide crucial insights into how various factors in fl uence rates of typhoid fever. 10 This is why the study by Ng ’ eno et al., published in a recent issue of the American Journal of Tropical Medicine and Hygiene , is so relevant. 11 Ng ’ eno et al. provide a decade of typhoid incidence data from the informal Kenyan settlement of Kibera. The authors report crude incidence rates ranging from 144 to 233 per 100,000 person-years of observation (pyo) between 2010 and 2012. This was followed by a decline in typhoid incidence from 2013 to 2017. Cases rebounded in the fi nal two years of surveillance, reaching 130 per 100,000 pyo in 2019. The authors

S. Trapitsin, O. Granichina, E. Agapova et al.

The attention of Arctic researchers is increasingly turning to the people who inhabit it. One of the objects of such research is the quality of life and subjective well-being of the indigenous peoples of the North, Siberia and the Far East, traditionally determined by the degree of satisfaction of needs, interests and expectations, the level of comfort of the social and natural environment for human life, the degree of trust in social institutions, accessibility and quality of social services, which determine the level of well-being, social, spiritual and physical health of people. Health is one of the key indicators of the quality of life. The analysis of health of youth of the indigenous small-numbered peoples of the North, Siberia and the Far East (ISNPNS and FE) creates the basis for the development of comprehensive health-saving programs, forecasting and organizing effective measures to preserve and strengthen the health of people arriving in the Far North in the conditions of its active industrial development. Health indicators are determined by approaches to its assessment, which involve taking into account a variety of information. Empirical data on the health factors of the ISNPNS and FE have been accumulated in Russia, but there is a lack of knowledge about the degree of their influence on the quality of life of children and youth. Representative data on the peculiarities of the health of adolescents and youth of the ISNPNS and FE of the Russian Federation in various regions, its impact on subjective well-being and quality of life are presented. Behavioral patterns in relation to various aspects of health, experiences of interaction with and attitudes towards official and alternative medicine are analyzed; environmental factors significant in the context of health care are identified.

J. S. Pallister, D. M. Gangardt, A. G. Abanov

We consider a free fermion formulation of a statistical model exhibiting a limit shape phenomenon. The model is shown to have a phase transition that can be visualized as the merger of two liquid regions - arctic circles. We show that the merging arctic circles provide a space-time resolved picture of the phase transition in lattice QCD known as Gross-Witten-Wadia transition. The latter is a continuous phase transition of the third order. We argue that this transition is universal and is not spoiled by interactions if parity and time-reversal symmetries are preserved. We refer to this universal transition as the Merger Transition.

Srikanth Toppaladoddi, Andrew J. Wells

The physics of planetary climate features a variety of complex systems that are challenging to model as they feature turbulent flows. A key example is the heat flux from the upper ocean to the underside of sea ice which provides a key contribution to the evolution of the Arctic sea ice cover. Here, we develop a model of the turbulent ice-ocean heat flux using coupled ordinary stochastic differential equations to model fluctuations in the vertical velocity and temperature in the Arctic mixed layer. All the parameters in the model are determined from observational data. A detailed comparison between the model results and measurements made during the Surface Heat Budget of the Arctic Ocean (SHEBA) project reveals that the model is able to capture the probability density functions (PDFs) of velocity, temperature and heat flux fluctuations. Furthermore, we show that the temperature in the upper layer of the Arctic ocean can be treated as a passive scalar during the whole year of SHEBA measurements. The stochastic model developed here provides a computationally inexpensive way to compute an observationally consistent PDF of this heat flux, and has implications for its parametrization in regional and global climate models.

PLOS Neglected Tropical Diseases Staff

[This corrects the article DOI: 10.1371/journal.pntd.0008328.].

Ana Amélia Nunes Santos, Priscyla Dos Santos Ribeiro, Geórgia Virgínia da França et al.

Rattus norvegicus (Norway rat) is the main reservoir host of pathogenic Leptospira, the causative agent of leptospirosis, in urban environments. Pathogenic Leptospira forms biofilms in the environment, possibly contributing for bacterial survival and maintenance. Nonetheless, biofilms have not yet been studied in natural animal reservoirs presenting leptospiral renal carriage. Here, we described biofilm formation by pathogenic Leptospira inside the renal tubules of R. norvegicus naturally infected and captured in an urban slum endemic for leptospirosis. From the 65 rats carrying Leptospira in their kidneys, 24 (37%) presented biofilms inside the renal tubules. The intensity of leptospiral colonization in the renal tubules (OR: 1.00; 95% CI 1.05-1.1) and the type of occlusion pattern of the colonized renal tubules (OR: 3.46; 95% CI 1.20-9.98) were independently associated with the presence of Leptospira biofilm. Our data showed that Leptospira interrogans produce biofilms during renal chronic colonization in rat reservoirs, suggesting a possible role for leptospiral biofilms in the pathogenesis of leptospirosis and bacterial carriage in host reservoirs.