90 research outputs found

    Remarks on SHD spaces and more divergence properties

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    The class of SHD spaces was recently introduced in [12]. The first part of this paper focuses on answering most of the questions presented in that article. For instance, we exhibit an example of a non-SHD Tychonoff space XX such that F[X]\mathscr{F}[X], the Pixley-Roy hyperspace of XX, βX\beta X, the Stone-\v{C}ech compactification of XX, and Cp(X)C_p(X), the ring of continuous functions over XX equipped with the topology of pointwise convergence, are SHD. In the second part of this work we will present some variations of the SHD notion, namely, the WSHD property and the OHD property. Furthermore, we will pay special attention to the relationships between XX and F[X]\mathscr{F}[X] regarding these new concepts

    Influence of sugarcane burning on soil carbon and nitrogen release under drought and evapotranspiration conditions in a Mexican sugarcane supply zone

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    "Sugarcane cultivation is an agricultural activity of worldwide importance. This crop has been cultivated in Mexico for centuries, impacting important productive areas like the study region called Huasteca Potosina which is located at the Central-East part of Mexico. The relationship between soil conditions, weather and production per hectare allows identifying the edaphological and climatic conditions (aptitude levels) for cultivating sugarcane in the study area. The objective of this research work is to analyze the relation between the cultivated hectares and production of sugarcane. Likewise, to explain its behavior and interpret the contribution of N and C released to the atmosphere for burning sugar cane in association with events and meteorological parameters involved in the flux of water between soil and atmosphere such as drought, evapotranspiration and rainfall. The methods and indicators for burning waste provided by the Intergovernmental Panel on Climate Change (IPCC), the value of potential evapotranspiration as Thornthwaite and drought severity index were applied in order to understand the correlations between the drought severity index and potential evapotranspiration, and between C and N release and potential rainfall availability. The results show the increment of harvested hectares and the loss of water from the soil by the increase of periods of drought events and evapotranspiration. The volatilized nutrients in soil varied from 1.32 x 105 to 2.17 x 105 t for C and from 1.32 x 103 t to 2.17 x 103 t for N during the burning of sugarcane, affecting production levels with values fluctuating between 38 t/ha to 77 t/ha for the term of 1990-2010.""El cultivo de caña de azúcar es una actividad agrícola de importancia mundial llevada a cabo en México durante siglos, impactando importantes áreas productivas como la región de estudio llamada Huasteca Potosina, localizada al este central de México. La relación entre las condiciones del suelo, clima y producción por hectárea permite identificar las condiciones edafológicas y climáticas (niveles de aptitud) para cultivar la caña de azúcar en el área de estudio. Bajo este contexto, el objetivo fue analizar la relación entre las hectáreas cultivadas y la producción de caña de azúcar y explicar su comportamiento al interpretar las contribuciones del N y C liberados a la atmósfera por la quema de caña asociados a eventos y parámetros meteorológicos involucrados en el flujo de agua entre el suelo y la atmósfera como sequía, evapotranspiración y lluvia. Los métodos e indicadores para la quema de residuos provistos por el Panel Intergubernamental del Cambio Climático (IPCC. por sus siglas en inglés), el valor de la evapotranspiración potencial por Thornthwaite y el índice de severidad de la sequía fueron aplicados para comprender las correlaciones entre el índice de severidad de la sequía y la evapotranspiración potencial, así como entre el C y el N liberados y la disponibilidad potencial de lluvia. Los resultados muestran el incremento en las hectáreas cosechadas y la pérdida de agua del suelo por el aumento de los periodos de sequía y la evapotranspiración. Los nutrientes del suelo volatilizados, varían de 1.32 x 105 ton a 2.17 x 105 ton para C y 1.32 x 103 ton a 2.17 x 103 ton para N durante la quema de caña de azúcar, lo que afecta sus niveles de producción con valores que fluctúan entre 38 t/ha y 77 t/ha durante el periodo 1990-2010.

    Depopulation impacts on ecosystem services in Mediterranean rural areas

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    Despite the exponential increase in human population at global scale, some rural areas have experienced a progressive abandonment over the last decades. Under particular socioecological and policy contexts, changes in demography may promote land-use changes and, consequently, alter ecosystem services (ES) supply. However, most studies on this topic have targeted urban population increase, whereas depopulation has been rarely addressed. Here, we examined how shifts in demographic variables (human population, population density, and number of villages) affect provisioning (water supply, food and biomass production) and regulating (soil retention, water and nutrient regulation) ES in Mediterranean rural areas with contrasting environmental, so-cioeconomic and land-use contexts. When depopulation results in underuse of socio-ecological systems, we ex-pected a decrease of provisioning and an increase of regulating ES, whereas we expected the opposite pattern when it results in land-use intensification. To test this hypothesis, we compared demographic data and ES estimated with Soil and Water Assessment Tool (SWAT) linked to land-use changes between the 1950s and 2000s in three rural areas of Arag ́on (NE Spain). Generalized Additive Mixed Models and Linear Mixed-Effect Models were used to analyze demographic trends, ES changes and the relationship between them. We found severe depopulation (− 42% inhabitants) and associated land-use changes in the three areas, which was particularly evident in isolated mountainous zones (− 63% inhabitants). Depopulation trends significantly affected land use and, consequently, all of the ES evaluated. In mountainous depopulated areas, land abandonment and rewilding resulted in the increase in water regulation (>1000%) and soil retention (>400%). In contrast, agriculture was intensified in more fertile and easy-to-access lowland areas, boosting the food production service (>600%). Accordingly, the interactions among depopulation, crop production and regulating ES should be considered in the management schemes and policies targeting rural areas for a balanced and sustainable supply of ES in the long term

    Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines

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    Background: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools. Methods: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, see Supplementary data) concluded the following: Results: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50–200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico. Conclusions: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed

    Estudios actuales de literatura comparada. Teorías de la literatura y diálogos interdisciplinarios

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    Estos dos volúmenes constituyen una contribución al desarrollo de la comparatística que se realiza, principalmente, desde América Latina. El primer volumen está organizado en tres partes y consta de 22 artículos, mientras que el segundo reúne 24 capítulos.UCR::Vicerrectoría de Docencia::Artes y Letras::Facultad de Letras::Escuela de Filología, Lingüística y LiteraturaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Sistema de Educación General::Escuela de Estudios GeneralesUCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Artes y Letras::Maestría Académica en Literatura FrancesaUCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Artes y Letras::Maestría Académica en Literatura LatinoamericanaUCR::Vicerrectoría de Docencia::Artes y Letras::Facultad de Letras::Escuela de Lenguas Moderna

    Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

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    Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

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    Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
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