139 research outputs found
Reserva Forestal El Montuoso: Vinculación económica de las comunidades de influencia con su ecosistema
The communities’ economic link to the Forest Reserve El Montuoso (FRM) was analyzed using a stra-tified cluster sampling. Communities depend on the direct benefits from this ecosystem for its survival, through the availability (87 per cent of the homes) and use of their lands for agricultural purposes (74 per cent), in rice and corn crops for self-consumption, and livestock and poultry production (76 per cent), mainly chickens and pigs. Crop and livestock farming allow residents to have access to unpaid jobs or self-employments (53 per cent) and to paid jobs, mainly for temporary farmworkers. Likewise, 67 per cent of the families generate monetary re-venues through the sale of products, mainly livestock. The families’ income indicators are all relatively low evidencing the high state of poverty of these communities. The benefits obtained by the FRM are threatened by the degradation of the ecosystem as a result of deforestation, the use of inappropriate technologies, such as tree-felling and burning, and the non-incorporation of conservation practices. Utilizando un muestreo estratificado por conglomerado, se analizó la vinculación económica de las comunidades con la Reserva Forestal El Montuoso (RFM). Las comunidades dependen, para su supervivencia, de los beneficios directos obtenidos de este ecosistema, a través de la disponibilidad (87% de los hogares) y uso de sus tierras en la agricultura (74%), en cultivos de arroz y maíz para el autoconsumo y en la producción pecuaria (76%), principalmente aves y cerdos. Las actividades agropecuarias permiten a estos habitantes acceder al empleo no asalariado o autoempleo (53%) y al asalariado, sobre todo como jornalero eventual (57%). Igualmente, el 67%de las familias genera ingresos monetarios con la venta de productos mayormente pecuarios. Todos los indica-dores de ingreso familiar son relativamente muy bajos, mostrando estas comunidades un estado de marcada pobreza. Los beneficios obtenidos de la RFM están amenazados por una degradación del ecosistema, caracteri-zado por la deforestación, uso de tecnologías no apropiadas, como tala y quema, y la no incorporación de prác-ticas de conservación
Alternative networks: toward global access to the Internet for all
It is often said that the Internet is ubiquitous in our daily lives, but this holds true only for those who can easily access it. In fact, billions of people are still digitally disconnected, as bringing connectivity to certain zones does not make a good business case. The only solution for these unsatisfied potential users is to directly undertake the building of the infrastructure required to obtaining access to the Internet, typically forming groups in order to share the corresponding cost. This article presents a global classification and a summary of the main characteristics of different Alternative Network deployments that have arisen in recent years with an aim to provide Internet services in places where mainstream network deployments do not exist or are not adequate solutions. The Global Access to the Internet for All Research Group of the Internet Research Task Force, where all authors actively participate, is interested in documenting these emerging deployments. As an outcome of this work, a classification has converged by consensus, where five criteria have been identified and, based on them, four different types of Alternative Networks have been identified and described with real-world examples. Such a classification is useful for a deeper understanding of the common characteristics behind existing and emerging Alternative Networks
Estimativa da ploidia de bananeira pela avaliação da turgescência foliar com wiltmeter®.
A duplicação cromossômica de diploides permite produzir plantas autotetraploides férteis que ao se cruzarem com diploides melhorados geram triploides secundários, podendo, assim, introduzir resistência a pragas e outras características desejáveis nos híbridos gerados (SILVA et al., 2011). No entanto, em trabalhos dessa natureza, há geração de grande número de plantas com diferentes ploidias, tendo necessidade de identificar rapidamente os autotetraplóides a serem mantidos, com o descarte das plantas com as demais ploidias. Para isso, faz-se necessário o uso de métodos diretos (contagem de cromossomos e citometria de fluxo) e indiretos (caracterização anatômica, como diâmetro do grão de pólen, número e tamanho de cloroplastídeos, tamanho de células) (SOUZA; QUEIROZ, 2004), para estimar a ploidia das plantas duplicadas
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Reactivation of low avidity tumor-specific CD8+ T cells associates with immunotherapeutic efficacy of anti-PD-1
Data availability statement:
Data are available on reasonable request. RNA sequencing data have been deposited in the Gene Expression Omnibus (GEO) under accession number GSE221590. All algorithms used for RNAseq analysis were publicly available R packages. Additional information required is available from the lead contact on request.Background: CD8+ T cells are a highly diverse population of cells with distinct phenotypic functions that can influence immunotherapy outcomes. Further insights on the roles of CD8+ specificities and TCR avidity of naturally arising tumor-specific T cells, where both high and low avidity T cells recognizing the same peptide-major histocompatibility complex (pMHC) coexist in the same tumor, are crucial for understanding T cell exhaustion and resistance to PD-1 immunotherapy.
Methods: CT26 models were treated with anti-PD-1 on days 3, 6 and 9 following subcutaneous tumor implantation generating variable responses during early tumor development. Tetramer staining was performed to determine the frequency and avidity of CD8+ T cells targeting the tumor-specific epitope GSW11 and confirmed with tetramer competition assays. Functional characterization of high and low avidity GSW11-specific CD8+ T cells was conducted using flow cytometry and bulk RNA-seq. In vitro cytotoxicity assays and in vivo adoptive transfer experiments were performed to determine the cytotoxicity of high and low avidity populations.
Results: Treatment success with anti-PD-1 was associated with the preferential expansion of low avidity (Tetlo) GSW11-specific CD8+ T cells with Vβ TCR expressing clonotypes. High avidity T cells (Tethi), if present, were only found in progressing PD-1 refractory tumors. Tetlo demonstrated precursor exhausted or progenitor T cell phenotypes marked by higher expression of Tcf-1 and T-bet, and lower expression of the exhaustion markers CD39, PD-1 and Eomes compared with Tethi, whereas Tethi cells were terminally exhausted. Transcriptomics analyses showed pathways related to TCR signaling, cytotoxicity and oxidative phosphorylation were significantly enriched in Tetlo found in both regressing and progressing tumors compared with Tethi, whereas genes related to DNA damage, apoptosis and autophagy were downregulated. In vitro studies showed that Tetlo exhibits higher cytotoxicity than Tethi. Adoptive transfer of Tetlo showed more effective tumor control than Tethi, and curative responses were achieved when Tetlo was combined with two doses of anti-PD-1.
Conclusions: Targeting subdominant T cell responses with lower avidity against pMHC affinity neoepitopes showed potential for improving PD-1 immunotherapy. Future interventions may consider expanding low avidity populations via vaccination or adoptive transfer.Worldwide Cancer Research Fund (20-0229) awarded to TE and Cancer Research UK Programme Grant (A28279) awarded to TE and EJ
Aplicación de un modelo para predecir las reservas de carbono orgánico en un suelo monocultivado con caña de azúcar en condiciones tropicales de cuba
Para la simulación del carbono orgánico del suelo se utilizó el modelo RothC26.3 (Coleman y Jenkinson, 1999), que trabaja a una escala de tiempo mensual y permite determinar el recambio mensual del C mediante procesos cinéticos de primer orden, donde las tasas de descomposición de sus cuatro reservorios activos, son moduladas por la temperatura, la humedad y la cubierta de residuos. La investigación se realizó tomando como base la información de carbono orgánico del suelo y rendimientos agrícolas de experimentos desarrollados en áreas agrícolas de la Estación Provincial de Investigaciones de la Caña de Azúcar (EPICA) ubicada en Jovellanos, provincia Matanzas en el periodo comprendido entre 1981 y 2010. Los datos de carbono orgánico de la capa cultivable del suelo (0-20 cm), clasificado como Ferralsol plantado con caña de azúcar, correspondientes al ciclo caña planta, sirvieron de base para parametrizar el modelo, cuyo comportamiento fue modificado por las variables climáticas, procedentes de la estación meteorológica asociada al lugar. La comparación entre los datos de carbono orgánico del suelo simulados y los observados en el período 1981-2010, resultó en que los primeros expresaron 95,58% de la varianza de los datos experimentales. Se encontró que la cantidad necesaria de carbono orgánico para mantener el nivel que tenía el suelo en 1981fue de 6,28 t ha-1 año-1. Los resultados soportan el uso del modelo RothC26.3 como una herramienta para predecir el comportamiento del COS en condiciones tropicales
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Chemical Fate of Contaminants in the Environment: Chlorinated Hydrocarbons in the Groundwater
Chlorinated hydrocarbons (CHCs) are the most common contaminant found at hazardous waste sites and are the most prevalent contaminants on U.S. Department of Energy (DOE) weapons production sites. Many of the CHCs are either known or suspected carcinogens and thus pose health risks to the public and/or site workers. Unlike simple hydrocarbons, CHCs are resistant to biodegradation, but can degrade by abiotic processes such as hydrolysis, nucleophilic substitution, and dehydrochlorination. Unfortunately, few studies of the reactions of chlorinated hydrocarbons have been reported in literature, and disagreement still exists about the mechanisms and rates of many of the key reactions. In this work, we modeled the reactions involved in the degradation of CHCs in the groundwater. The goals of the research proposed are: • development of a computational approach that will allow reaction pathways and rate constants to be accurately calculated • development of more approximate approaches, evaluated against the more accurate approach, which will lay the groundwork for exploratory studies of more complex CHCs • application of these approaches to study the degradation pathways of CHCs in aqueous liquids • application of the more approximate approaches to study the mechanism of forming complex CHC polychlorinated benzene compounds and dioxins. We examined elementary reactions involved in the aqueous-phase chemistry of chlorinated methanes and ethylenes in an attempt to obtain a detailed understanding of the abiotic processes involved in the degradation of this important class of contaminants. We began by studying the reactions of CHnCl(4-n) and C2HnCl(4-n) with OH¯, as these are thought to be the dominant processes involved in the degradation of these chlorinated species. We used state-of-the-art theoretical techniques to model the elementary reactions of CHCs important in the groundwater. We employed high-accuracy electronic structure methods (e.g., perturbation theory and coupled cluster methods with correlation-consistent basis sets) to determine the energies of the various stable species, intermediates, and transition states involved in the elementary reactions of CHCs. Effects of solvation on the reaction energetics were studied by including small numbers of solvent molecules (microsolvation). Our own N-layered molecular orbital + molecular mechanics (ONIOM) method was used because it allows the number of solvent molecules to be increased, and hybrid quantum mechanical/molecular mechanics (QM/MM) methods and continuum solvation models were used to estimate the effects of bulk solvation. Rate constants for the gas-phase, microsolvated, and bulk-phase reactions were computed using variational transition state theory (VTST)
Acculturation and use of health care services by Turkish and Moroccan migrants: a cross-sectional population-based study
<p>Abstract</p> <p>Background</p> <p>There is insufficient empirical evidence which shows if and how there is an interrelation between acculturation and health care utilisation. The present study seeks to establish this evidence within first generation Turkish and Moroccan migrants, two of the largest migrant groups in present-day Western Europe.</p> <p>Methods</p> <p>Data were derived from the Amsterdam Health Monitor 2004, and were complete for 358 Turkish and 288 Moroccan foreign-born migrants. Use of health services (general practitioner, outpatient specialist and health care for mental health problems) was measured by means of self-report. Acculturation was measured by a structured questionnaire grading (i) ethnic self-identification, (ii) social interaction with ethnic Dutch, (iii) communication in Dutch within one's private social network, (iv) emancipation, and (v) cultural orientation towards the public domain.</p> <p>Results</p> <p>Acculturation was hardly associated with the use of general practitioner care. However, in case of higher adaptation to the host culture there was less uptake of outpatient specialist care among Turkish respondents (odds ratio [OR] = 0.90, 95% confidence interval [CI] = 0.82-0.99) and Moroccan male respondents (OR = 0.81, 95% CI = 0.71-0.93). Conversely, there was a higher uptake of mental health care among Turkish men (OR = 0.81, 95% CI = 0.71-0.93) and women (OR = 0.81, 95% CI = 0.71-0.93). Uptake of mental health care among Moroccan respondents again appeared lower (OR = 0.74, 95% CI = 0.55-0.99). Language ability appeared to play a central role in the uptake of health care.</p> <p>Conclusion</p> <p>Some results were in accordance with the popular view that an increased participation in the host society is concomitant to an increased use of health services. However, there was heterogeneity across ethnic and gender groups, and across the domains of acculturation. Language ability appeared to play a central role. Further research needs to explore this heterogeneity into more detail. Also, other cultural and/or contextual aspects that influence the use of health services require further identification.</p
Maternal Perception of Child Weight Among Mexicans in California and Mexico
The prevalence of childhood overweight is high in Mexican immigrant communities in the United States. Understanding mother’s perceptions of child weight in immigrants’ country of origin may help to understand this high prevalence. The goal of this study was to examine and compare mothers’ perception of weight in Mexico (MX) and in an immigrant community in California (CA). We assessed perceptions of child weight using a pictorial scale with 314 mothers of 5-year-old children in MX and 60 mothers of 5 year-old-children in CA. We compared maternal reports with children’s objectively measured weight. Using chi-square and Analysis of Variance, we investigated associations of maternal perception of and satisfaction with weight according to socio-demographic characteristics. Mothers were more likely to underestimate their children’s weight in CA than in MX. On average, CA mothers wanted their children to be smaller than they currently were and mothers in MX wanted their children to be bigger than they currently were. This differed by weight status in CA with mothers of normal weight and at-risk-for-overweight children wanting them to be bigger and mothers of overweight children wanting them to be smaller. In order for programs to be effective, mothers must be able to recognize their children as overweight and want to address it. Because underestimation of weight and a desire for a larger size is common in this population, programs to address overweight may be more effective if they focus on alternative benefits of weight control strategies, such as healthy child development
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