Gause's exclusion principle revisited: artificial modified species and competition

Gause's principle of competition between two species is studied when one of them is sterile. We study the condition for total extinction in the niche, namely, when the sterile population exterminates the native one by an optimal use of resources. A mathematical Lotka-Volterra non linear model of interaction between a native and sterile species is proposed. The condition for total extinction is related to the initial number $M_{o}$ of sterile individuals released in the niche. In fact, the existence of a critical sterile-population value $M_{c}$ is conjectured from numerical analysis and an analytical estimation is found. When spatial diffusion (migration) is considered a critical size territory is found and, for small territory, total extinction exist in any case. This work is motived by the extermination agriculture problem of fruit flies in our region.Comment: 11 pages. Published in Jour.Phys.A Math.Gen. 33, 4877 (2000

A systematic review and narrative synthesis of footwear and orthotic devices used in the management of ankle haemarthrosis and haemarthropathy in haemophilia

Introduction Haemarthrosis is a clinical feature of haemophilia leading to haemarthropathy. The ankle joint is most commonly affected, resulting in significant pain, disability and a reduction in health-related quality of life. Footwear and orthotic devices are effective in other diseases that affect the foot and ankle, such as rheumatoid arthritis, but little is known about their effect in haemophilia. Aims To review the efficacy and effectiveness of footwear and orthotic devices in the management of ankle joint haemarthrosis and haemarthropathy in haemophilia. Methods A systematic literature review was conducted. Two review authors independently screened studies for inclusion and appraised methodological quality using Joanna Briggs Institute Critical Appraisal checklists. A narrative analysis was undertaken. Results Ten studies involving 271 male participants were eligible for inclusion. All studies were quasi-experimental; three employed a within-subject design. Two studies included an independent comparison or control group. A range of footwear and orthotic devices were investigated. Limited evidence from non-randomised studies suggested that footwear and orthotic devices improve the number of ankle joint bleeding episodes, gait parameters, and patient-reported pain. Conclusion This review demonstrates a lack of robust evidence regarding the efficacy and effectiveness of footwear and orthotic devices in the management of ankle joint haemarthrosis and haemarthropathy in haemophilia. Methodological heterogeneities and limitations with the study designs, small sample sizes and limited follow-up of participants exist. Future studies utilising randomised designs, larger sample sizes, long-term follow-up, and validated patient-reported outcome measures are needed to inform the clinical management of ankle joint haemarthrosis and haemarthropathy

Ionic Liquid Aqueous Two-Phase Systems for the Enhanced Paper-Based Detection of Transferrin and Escherichia coli

Aqueous two-phase systems (ATPSs) have been widely utilized for liquid-liquid extraction and purification of biomolecules, with some studies also demonstrating their capacity as a biomarker concentration technique for use in diagnostic settings. As the limited polarity range of conventional polymer-based ATPSs can restrict their use, ionic liquid (IL)-based ATPSs have been recently proposed as a promising alternative to polymer-based ATPSs, since ILs are regarded as tunable solvents with excellent solvation capabilities for a variety of natural compounds and proteins. This study demonstrates the first application of IL ATPSs to point-of-care diagnostics. ATPSs consisting of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) and sodium phosphate salt were utilized to quickly concentrate biomarkers prior to detection using the lateral-flow immunoassay (LFA). We found the phase separation speed of the IL ATPS to be very rapid and a significant improvement upon the separation speed of both polymer-salt and micellar ATPSs. This system was successfully applied to both sandwich and competitive LFA formats and enhanced the detection of both Escherichia coli bacteria and the transferrin protein up to 8- and 20-fold, respectively. This system's compatibility with a broad range of biomolecules, rapid phase separation speed, and tunability suggest wide applicability for a large range of different antigens and biomarkers

Better together: data harmonization and cross-study analysis of abdominal MRI data from UK Biobank and the German National Cohort

OBJECTIVES: The UK Biobank (UKBB) and German National Cohort (NAKO) are among the largest cohort studies, capturing a wide range of health-related data from the general population, including comprehensive magnetic resonance imaging (MRI) examinations. The purpose of this study was to demonstrate how MRI data from these large-scale studies can be jointly analyzed and to derive comprehensive quantitative image-based phenotypes across the general adult population. MATERIALS AND METHODS: Image-derived features of abdominal organs (volumes of liver, spleen, kidneys, and pancreas; volumes of kidney hilum adipose tissue; and fat fractions of liver and pancreas) were extracted from T1-weighted Dixon MRI data of 17,996 participants of UKBB and NAKO based on quality-controlled deep learning generated organ segmentations. To enable valid cross-study analysis, we first analyzed the data generating process using methods of causal discovery. We subsequently harmonized data from UKBB and NAKO using the ComBat approach for batch effect correction. We finally performed quantile regression on harmonized data across studies providing quantitative models for the variation of image-derived features stratified for sex and dependent on age, height, and weight. RESULTS: Data from 8791 UKBB participants (49.9% female; age, 63 ± 7.5 years) and 9205 NAKO participants (49.1% female, age: 51.8 ± 11.4 years) were analyzed. Analysis of the data generating process revealed direct effects of age, sex, height, weight, and the data source (UKBB vs NAKO) on image-derived features. Correction of data source-related effects resulted in markedly improved alignment of image-derived features between UKBB and NAKO. Cross-study analysis on harmonized data revealed comprehensive quantitative models for the phenotypic variation of abdominal organs across the general adult population. CONCLUSIONS: Cross-study analysis of MRI data from UKBB and NAKO as proposed in this work can be helpful for future joint data analyses across cohorts linking genetic, environmental, and behavioral risk factors to MRI-derived phenotypes and provide reference values for clinical diagnostics

Living with foot and ankle disorders in rheumatic and musculoskeletal diseases: A systematic review of qualitative studies to inform the work of the OMERACT foot and ankle working group

ObjectivesThis study aimed to determine outcome domains of importance to patients living with foot and ankle disorders in rheumatic and musculoskeletal diseases (RMDs), by exploring the symptoms and impact of these disorders reported in existing qualitative studies.MethodsSix databases were searched from inception to March 2022. Studies were included if they used qualitative interview or focus group methods, were published in English, and involved participants living with RMDs (inflammatory arthritis, osteoarthritis, crystal arthropathies, connective tissue diseases, and musculoskeletal conditions in the absence of systemic disease) who had experienced foot and ankle problems. Quality was assessed using the Critical Appraisal Skills Programme qualitative tool and confidence in the findings was assessed using the Grading of Recommendations Assessment, Development and Evaluation Confidence in the Evidence from Reviews of Qualitative research (GRADE-CERQual) approach. All data from the results section of included studies were extracted, coded and synthesised to develop themes.ResultsOf 1,443 records screened, 34 studies were included, with a total of 503 participants. Studies included participants with rheumatoid arthritis (n = 18), osteoarthritis (n = 5), gout (n = 3), psoriatic arthritis (n = 1), lupus (n = 1), posterior tibial tendon dysfunction (n = 1), plantar heel pain (n = 1), Achilles tendonitis (n = 1), and a mixed population (n = 3), who live with foot and ankle disorders. Seven descriptive themes were generated from the thematic synthesis: pain, change in appearance, activity limitations, social isolation, work disruption, financial burden and emotional impact. Descriptive themes were inductively analysed further to construct analytical themes relating to potential outcome domains of importance to patients. Foot or ankle pain was the predominant symptom experienced by patients across all RMDs explored in this review. Based on grading of the evidence, we had moderate confidence that most of the review findings represented the experiences of patients with foot and ankle disorders in RMDs.ConclusionsFindings indicate that foot and ankle disorders impact on multiple areas of patients’ lives, and patients’ experiences are similar regardless of the RMD. This study will inform the development of a core domain set for future foot and ankle research and are also useful for clinicians, helping to focus clinical appointments and measurement of outcomes within clinical practice

'You give us rangoli, we give you talk': using an art-based activity to elicit data from a seldom heard group

<p>Abstract</p> <p>Background</p> <p>The exclusion from health research of groups most affected by poor health is an issue not only of poor science, but also of ethics and social justice. Even if exclusion is inadvertent and unplanned, policy makers will be uninformed by the data and experiences of these groups. The effect on the allocation of resources is likely to be an exacerbation of health inequalities.</p> <p>Discussion</p> <p>We subject to critical analysis the notion that certain groups, by virtue of sharing a particular identity, are inaccessible to researchers - a phenomenon often problematically referred to as 'hard to reach'. We use the term 'seldom heard' to move the emphasis from a perceived innate characteristic of these groups to a consideration of the methods we choose as researchers. Drawing on a study exploring the intersections of faith, culture, health and food, we describe a process of recruitment, data collection and analysis in which we sought to overcome barriers to participation. As we were interested in the voices of South Asian women, many of whom are largely invisible in public life, we adopted an approach to data collection which was culturally in tune with the women's lives and values. A collaborative activity mirroring food preparation provided a focus for talk and created an environment conducive to data collection. We discuss the importance of what we term 'shoe leather research' which involves visiting the local area, meeting potential gatekeepers, and attending public events in order to develop our profile as researchers in the community. We examine issues of ethics, data quality, management and analysis which were raised by our choice of method.</p> <p>Summary</p> <p>In order to work towards a more theoretical understanding of how material, social and cultural factors are connected and influence each other in ways that have effects on health, researchers must attend to the quality of the data they collect to generate finely grained and contextually relevant findings. This in turn will inform the design of culturally sensitive health care services. To achieve this, researchers need to consider methods of recruitment; the makeup of the research team; issues of gender, faith and culture; and data quality, management and analysis.</p

Identification of priority health conditions for field-based screening in urban slums in Bangalore, India

BACKGROUND: Urban slums are characterised by unique challenging living conditions, which increase their inhabitants' vulnerability to specific health conditions. The identification and prioritization of the key health issues occurring in these settings is essential for the development of programmes that aim to enhance the health of local slum communities effectively. As such, the present study sought to identify and prioritise the key health issues occurring in urban slums, with a focus on the perceptions of health professionals and community workers, in the rapidly growing city of Bangalore, India. METHODS: The study followed a two-phased mixed methods design. During Phase I of the study, a total of 60 health conditions belonging to four major categories: - 1) non-communicable diseases; 2) infectious diseases; 3) maternal and women's reproductive health; and 4) child health - were identified through a systematic literature review and semi-structured interviews conducted with health professionals and other relevant stakeholders with experience working with urban slum communities in Bangalore. In Phase II, the health issues were prioritised based on four criteria through a consensus workshop conducted in Bangalore. RESULTS: The top health issues prioritized during the workshop were: diabetes and hypertension (non-communicable diseases category), dengue fever (infectious diseases category), malnutrition and anaemia (child health, and maternal and women's reproductive health categories). Diarrhoea was also selected as a top priority in children. These health issues were in line with national and international reports that listed them as top causes of mortality and major contributors to the burden of diseases in India. CONCLUSIONS: The results of this study will be used to inform the development of technologies and the design of interventions to improve the health outcomes of local communities. Identification of priority health issues in the slums of other regions of India, and in other low and lower middle-income countries, is recommended

A multidisciplinary systematic review of the use of diagrams as a means of collecting data from research subjects: application, benefits and recommendations

BACKGROUND: In research, diagrams are most commonly used in the analysis of data and visual presentation of results. However there has been a substantial growth in the use of diagrams in earlier stages of the research process to collect data. Despite this growth, guidance on this technique is often isolated within disciplines. METHODS: A multidisciplinary systematic review was performed, which included 13 traditional healthcare and non-health-focused indexes, non-indexed searches and contacting experts in the field. English-language articles that used diagrams as a data collection tool and reflected on the process were included in the review, with no restriction on publication date. RESULTS: The search identified 2690 documents, of which 80 were included in the final analysis. The choice to use diagrams for data collection is often determined by requirements of the research topic, such as the need to understand research subjects' knowledge or cognitive structure, to overcome cultural and linguistic differences, or to understand highly complex subject matter. How diagrams were used for data collection varied by the degrees of instruction for, and freedom in, diagram creation, the number of diagrams created or edited and the use of diagrams in conjunction with other data collection methods. Depending on how data collection is structured, a variety of options for qualitative and quantitative analysis are available to the researcher. The review identified a number of benefits to using diagrams in data collection, including the ease with which the method can be adapted to complement other data collection methods and its ability to focus discussion. However it is clear that the benefits and challenges of diagramming depend on the nature of its application and the type of diagrams used. DISCUSSION/CONCLUSION: The results of this multidisciplinary systematic review examine the application of diagrams in data collection and the methods for analyzing the unique datasets elicited. Three recommendations are presented. Firstly, the diagrammatic approach should be chosen based on the type of data needed. Secondly, appropriate instructions will depend on the approach chosen. And thirdly, the final results should present examples of original or recreated diagrams. This review also highlighted the need for a standardized terminology of the method and a supporting theoretical framework