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

Predicting transmittance spectra of electrophotographic color prints

For dry toner electrophotographic color printers, we present a numerical simulation model describing the color printer response based on a physical characterization of the different electrophotographic process steps. The proposed model introduces a Cross Transfer Efficiency designed to predict the color transmittance spectra of multi-color prints by taking into account the transfer influence of each deposited color toner layer upon the other layers. The simulation model leads to a better understanding of the factors that have an impact on printing quality. In order to avoid the additional optical non-linearities produced by light reflection on paper (dot-gain), we have limited the present investigation to transparency prints. The proposed model succeeded to predict the transmittance spectra of printed wedges combining two color toner layers with a mean deviation less than CIE-LAB ΔE = 2.5

Ground-based off-line aerosol measurements at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: Microphysical properties and mineralogy

A large field experiment of the Saharan Mineral Dust Experiment (SAMUM) was performed in Praia, Cape Verde, in January and February 2008. This work reports on the aerosol mass concentrations, size distributions and mineralogical composition of the aerosol arriving at Praia. Three dust periods were recorded during the measurements, divided by transitional periods and embedded in maritime-influenced situations. The total suspended particle mass/PM10/PM2.5 were 250/180/74μg/m3 on average for the first dust period (17–21 January) and 250/230/83μg/m3 for the second (24–26 January). The third period (28 January to 2 February) was the most intensive with 410/340/130 μg/m3. Four modes were identified in the size distribution. The first mode (50–70 nm) and partly the second (700–1100 nm) can be regarded as of marine origin, but some dust contributes to the latter. The third mode (2–4 μm) is dominated by advected dust, while the intermittently occurring fourth mode (15–70 μm) may have a local contribution. The dust consisted of kaolinite (dust/maritime period: 35%wt./25%wt.),K-feldspar (20%wt./25%wt.), illite (14%wt./10%wt.), quartz (11%wt./8%wt.), smectites (6%wt./4%wt.), plagioclase (6%wt./1%wt.), gypsum (4%wt./7%wt.), halite (2%wt./17%wt.) and calcite (2%wt./3%wt.)

Steady-state response of a random dynamical system described with Padé approximants and random eigenmodes

Designing a random dynamical system requires the prediction of the statistics of the response, knowing the random model of the uncertain parameters. Direct Monte Carlo simulation (MCS) is the reference method for propagating uncertainties but its main drawback is the high numerical cost. A surrogate model based on a polynomial chaos expansion (PCE) can be built as an alternative to MCS. However, some previous studies have shown poor convergence properties around the deterministic eigenfrequencies. In this study, an extended Pade approximant approach is proposed not only to accelerate the convergence of the PCE but also to have a better representation of the exact frequency response, which is a rational function of the uncertain parameters. A second approach is based on the random mode expansion of the response, which is widely used for deterministic dynamical systems. A PCE approach is used to calculate the random modes. Both approaches are tested on an example to check their efficiency

Sphagnum farming from species selection to the production of growing media : a review

Sphagnum farming - the production of Sphagnum biomass on rewetted bogs - helps towards achieving global climate goals by halting greenhouse gas emissions from drained peat and by replacing peat with a renewable biomass alternative. Large-scale implementation of Sphagnum farming requires a wide range of know-how, from initial species selection up to the final production and use of Sphagnum biomass based growing media in horticulture. This article provides an overview of relevant knowledge accumulated over the last 15 years and identifies open questions.Peer reviewe

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

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

Chromosome evolution in Neotropical butterflies

Peer reviewe

Identification, frequency, activation and function of CD4+ CD25highFoxP3+ regulatory T cells in children with juvenile idiopathic arthritis

The aim of the study was to test the frequency of CD4+ CD25highFoxP3 regulatory T cells in JIA patients and to assess their activation status and functional activity. The study involved 12 children with JIA and 35 healthy control subjects. PBMC were stained with monoclonal antibodies (anti-CD25, anti-CD4, anti-CD127, anti-CD69, anti-CD71, and anti-FoxP3). The samples were evaluated using flow cytometer. CD4+ CD25− and CD4+ CD25+ cells were isolated by negative and positive selection with magnetic microbeads. CD4+ CD25+ and CD4+ CD25− cells were cultured separately and co-cultured (1:1) with or without PHA. The percentage of Tregs in JIA patients was significantly decreased in comparison with controls (median, 3.2 vs. 4.6; P = 0.042). Relative fluorescence intensities of FoxP3 were higher in JIA patients than in controls (median, 9.1 vs. 6.8). The percentage of activated Tregs (CD71+) was significantly higher in JIA patients in comparison with controls (median, 6.5 vs. 2.8; P = 0.00043). CD4+ CD25+ cells derived from JIA patients and controls were anergic upon PHA stimulation, while CD4+ CD25− cells showed intensive proliferative response. The proliferation rate of CD4+ CD25− cells stimulated by PHA was decreased in co-cultures. In JIA patients, the inhibition of proliferation of CD4+ CD25− cells by CD4+ CD25+ cells was 37.9%, whereas in controls it was significantly lower (55.7%, P = 0.046). JIA patients had statistically lower percentage of Tregs in peripheral blood compared to controls. CD4+ CD25+ cells sorted from peripheral blood of JIA patients had statistically lower ability to suppress CD4+ CD25− cell proliferation in comparison with cells obtained from controls