On localized vegetation patterns, fairy circles and localized patches in arid landscapes

We investigate the formation of localized structures with a varying width in one and two-dimensional systems. The mechanism of stabilization is attributed to strong nonlocal coupling mediated by a Lorentzian type of Kernel. We show that, in addition to stable dips found recently [see, e.g., C. Fernandez-Oto, M. G. Clerc, D. Escaff, and M. Tlidi, Phys. Rev. Lett. {\bf{110}}, 174101 (2013)], exist stable localized peaks which appear as a result of strong nonlocal coupling, i.e. mediated by a coupling that decays with the distance slower than an exponential. We applied this mechanism to arid ecosystems by considering a prototype model of a Nagumo type. In one-dimension, we study the front that connects the stable uniformly vegetated state with the bare one under the effect of strong nonlocal coupling. We show that strong nonlocal coupling stabilizes both---dip and peak---localized structures. We show analytically and numerically that the width of localized dip, which we interpret as fairy circle, increases strongly with the aridity parameter. This prediction is in agreement with filed observations. In addition, we predict that the width of localized patch decreases with the degree of aridity. Numerical results are in close agreement with analytical predictions

Plant clonal morphologies and spatial patterns as self-organized responses to resource-limited environments

We propose here to interpret and model peculiar plant morphologies (cushions, tussocks) observed in the Andean altiplano as localized structures. Such structures resulting in a patchy, aperiodic aspect of the vegetation cover are hypothesized to self-organize thanks to the interplay between facilitation and competition processes occurring at the scale of basic plant components biologically referred to as 'ramets'. (Ramets are often of clonal origin.) To verify this interpretation, we applied a simple, fairly generic model (one integro-differential equation) emphasizing via Gaussian kernels non-local facilitative and competitive feedbacks of the vegetation biomass density on its own dynamics. We show that under realistic assumptions and parameter values relating to ramet scale, the model can reproduce some macroscopic features of the observed systems of patches and predict values for the inter-patch distance that match the distances encountered in the reference area (Sajama National Park in Bolivia). Prediction of the model can be confronted in the future to data on vegetation patterns along environmental gradients as to anticipate the possible effect of global change on those vegetation systems experiencing constraining environmental conditions.Comment: 14 pages, 6figure

Long term management of obstructive sleep apnea and its comorbidities

Obstructive sleep apnea (OSA) is a worldwide highly prevalent disease associated with systemic consequences, including excessive sleepiness, impairment of neurocognitive function and daytime performance, including driving ability. The long-term sequelae of OSA include and increase risk for cardiovascular, cerebrovascular and metabolic syndrome disorders that ultimately lead to premature death if untreated. To ensure optimal long-term outcomes, the assessment and management of OSA should be personalized with the involvement of the appropriate specialist. Most studies have demonstrated inmediate improvement in daytime somnolence and quality of life with CPAP and other therapies, but the effect of long-term treatment on mortality is still under debate. Currently, the long-term management of OSA should be based on a) identifying physiological or structural abnormalities that are treatable at the time of patient evaluation and b) comprehensive lifestyle interventions, especially weight-loss interventions, which are associated with improvements in OSA severity, cardiometabolic comorbidities, and quality of life. In long-term management, attention should be paid to the clinical changes related to a potential reoccurrence of OSA symptoms and it is also necessary to monitor throughout the follow up how the main associated comorbidities evolve

Long term management of obstructive sleep apnea and its comorbidities

Obstructive sleep apnea (OSA) is a worldwide highly prevalent disease associated with systemic consequences, including excessive sleepiness, impairment of neurocognitive function and daytime performance, including driving ability. The long-term sequelae of OSA include and increase risk for cardiovascular, cerebrovascular and metabolic syndrome disorders that ultimately lead to premature death if untreated. To ensure optimal long-term outcomes, the assessment and management of OSA should be personalized with the involvement of the appropriate specialist. Most studies have demonstrated inmediate improvement in daytime somnolence and quality of life with CPAP and other therapies, but the effect of long-term treatment on mortality is still under debate. Currently, the long-term management of OSA should be based on a) identifying physiological or structural abnormalities that are treatable at the time of patient evaluation and b) comprehensive lifestyle interventions, especially weight-loss interventions, which are associated with improvements in OSA severity, cardiometabolic comorbidities, and quality of life. In long-term management, attention should be paid to the clinical changes related to a potential reoccurrence of OSA symptoms and it is also necessary to monitor throughout the follow up how the main associated comorbidities evolve

Proportion and Factors Associated with Zinc Deficiency in Acute Diarrhea Patients

Background: Zinc may affect the intestinal immune response. No data has been available on zinc deficiency in adult patients with diarrhea, especially for Indonesian population. Zinc metabolism, etiologies, pathogenesis and clinical course of diarrhea may have various effects on zinc concentration in different population. This study aimed to determine the proportion of zinc deficiency in patients with acute diarrhea, including its associated factors. Method: A cross-sectional study was conducted in patients with acute diarrhea at outpatient clinics and emergency wards of four hospitals between August 2010 and March 2011. A serum zinc concentration of < 10.7 µmol/L was set as cut-off value for zinc deficiency. Data was analyzed by using Chi-square test. Results: There were 101 subjects, 54.5% were female, the median age was 26 years, median duration of acute diarrhea was 5 days, and the median frequency was 6 times/day. About 95% patients had nutritional status of subjective global assessment (SGA) A and the mean value of body mass index was 19.3 ± 0.70 kg/m2. Approximately 88.1% patients had severe infective diarrhea based on hydration status. About 69.3% patients were zinc deficient with the mean serum zinc concentration of 9.26 ± 2.95 µ mol/L. We found a significant correlation between the severity of diarrhea and zinc deficiency in patients with acute diarrhea. Conclusion: The proportion of zinc deficiency in acute diarrhea patients was quite large although the mean serum zinc level was still below the National Health and Nutrition Examination Survey (NHANES) reference value. The severity of diarrhea has been proven to be significant that affects zinc deficiency in acute diarrhea patients

Digital competence of university teachers of social and legal sciences from a gender perspective

Higher Education institutions must respond to the major challenges posed by the technological transformations of recent years. For this, one of the key aspects is that the teachers working in them are trained to incorporate these technologies in teaching–learning processes, which requires them to be digitally competent. To analyse how gender relates to the level of competence of teachers, the types of ICT tools that they use, and their attitudes towards their implementation in teaching– learning processes, this quantitative research was carried out with the participation of 121 university teachers from the Autonomous Community of Aragon, all of them from the area of Social and Legal Sciences. The results show a differentiated profile between men and women in terms of their attitudes, beliefs, and self-perception regarding their management skills and effectiveness. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Importance of Localized Skin Infection in Tick-Borne Encephalitis Virus Transmission

AbstractArboviruses are transmitted to vertebrates by the ”bite“ of infected arthropods. Events at the site of virus deposition are largely unknown despite increasing evidence that blood-sucking arthropods immunomodulate their skin site of feeding. This question is particularly relevant for ixodid ticks that feed for several days. To examine events under conditions mimicking tick-borne encephalitis (TBE) virus transmission in nature (i.e., infected and uninfectedIxodes ricinusticks feeding on the same animal), infected adult and uninfected nymphal ticks were placed in one retaining chamber (skin site A) and uninfected nymphs were placed within a second chamber posteriorly (skin site B) on two natural host species, yellow-necked field mice (Apodemus flavicollis) and bank voles (Clethrionomys glareolus). Virus transmission from infected to uninfected cofeeding ticks was correlated with infection in the skin site of tick feeding. Furthermore, virus was recruited preferentially to the site in which ticks were feeding compared with uninfested skin sites. Viremia did not correspond with a generalized infection of the skin; virus was not detected in an uninfested skin site (C) of 12/13 natural hosts that had viremia levels ≥2.0 log10ic mouse LD50/0.02 ml blood. To characterize infected cells, laboratory mouse strains were infested with infected ticks and then explants were removed from selected skin sites and floated on culture medium. Numerous leukocytes were found to migrate from the skin explants of tick feeding sites. Two-color immunocytochemistry revealed viral antigen in both migratory Langerhans cells and neutrophils; in addition, the migratory monocyte/macrophages were shown to produce infectious virus. The results indicate that the local skin site of tick feeding is an important focus of viral replication early after TBE virus transmission by ticks. Cellular infiltration of tick feeding sites, and the migration of cells from such sites, may provide a vehicle for transmission between infected and uninfected cofeeding ticks that is independent of a patent viremia. The data support the hypothesis that viremia is a product, rather than a prerequisite, of tick-borne virus transmission