163 research outputs found

    The “Good,” the “Bad,” and the Queer Invisible: The Los Angeles May Day Queer Contingent

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    This article explores the evolution of the May Day Queer Contingent (MDQC) as a part of the annual Los Angeles May Day march. The MDQC is a notable example of the political mobilization led by queer women and transgender activists of color of the LGBTQ community, as it relates to the struggle for immigrant rights. Offering reflections from founders and key organizers, this paper considers the development of the MDQC; its engagement with other groups; intersectionality and queer women of color feminisms as a political project to confront a heteropatriarchal immigration reform movement

    Evaluación de dos Métodos para el Aprovechamiento Turístico en Áreas Naturales Protegidas

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    El objetivo general fue realizar un análisis crítico del método de Límites de Cambio Aceptable y Capacidad de Carga Turística en áreas naturales protegidas, con énfasis en la propuesta de Cifuentes et al. (1999) por ser el instrumento más aplicado en América Latina. Se realizó una revisión bibliográfica de artículos científicos referidos al objeto de estudio. Como resultados, se determina que el método Cifuentes se enfoca en aspectos lineales, uni-dimensionales y parciales, no considera la homeóstasis y omite la zonificación previa, lo cual facilita su operacionalización en las áreas naturales protegidas pero genera valores heurísticos. Se sugiere fortalecer el método con la inclusión de aspectos sociales y económicos para integrar las tres dimensiones de la sustentabilidad, así como incorporar la zona de influencia al área natural protegida dentro del análisis integrador en la planificación turística

    Development of a genetic tool for functional screening of anti-malarial bioactive extracts in metagenomic libraries

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    Ajuts: Departamento Administrativo de Ciencias, Tecnología e Innovación (Colciencias), República de Colombia; Convocatoria 489 - 2009, Código 657048925406, Contrato de financiación RC. 427 - 2009 Colciencias - CorpoGen; Programa de Asistencias Graduadas de Universidad de los Andes, Bogotá, Colombia; i Programa Jóvenes Investigadores de ColcienciasBACKGROUND: The chemical treatment of Plasmodium falciparum for human infections is losing efficacy each year due to the rise of resistance. One possible strategy to find novel anti-malarial drugs is to access the largest reservoir of genomic biodiversity source on earth present in metagenomes of environmental microbial communities. METHODS: A bioluminescent P. falciparum parasite was used to quickly detect shifts in viability of microcultures grown in 96-well plates. A synthetic gene encoding the Dermaseptin 4 peptide was designed and cloned under tight transcriptional control in a large metagenomic insert context (30 kb) to serve as proof-of-principle for the screening platform. RESULTS: Decrease in parasite viability consistently correlated with bioluminescence emitted from parasite microcultures, after their exposure to bacterial extracts containing a plasmid or fosmid engineered to encode the Dermaseptin 4 anti-malarial peptide. Here, a new technical platform to access the anti-malarial potential in microbial environmental metagenomes has been develope

    Calidad de vida en personas con VIH-SIDA en tres instituciones de salud de Cali, Colombia

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    Antecedents: The Human Immunodeficiency Virus is currently considered a chronic disease; hence, quality of life is an important goal for those suffering the disease or living with someone afflicted by the virus. Objectives: We sought to measure the quality of life in individuals living with acquired immunodeficiency syndrome virus and establish its relationship with socio-demographic and clinical variables. Methods: This is a cross-sectional, descriptive study with a sample of 137 HIV-infected individuals attending three healthcare institutions in the city of Cali, Colombia. Quality of life was measured via the HIV/AIDS-Targeted Quality of Life (HAT-QoL) instrument. The descriptive analyses included mean and standard deviation calculations. To determine the candidate variables, we used the student t test and the Pearson correlation. The response variable in the multiple linear regression was the score for quality of life. Results: Some 27% of the sample were women and 3% were transgender; the mean age of the sample was 35 + 10.2 years; 88% had some type of health insurance; 27% had been diagnosed with AIDS, and 64% were taking antiretroviral medications at the time of the study. Quality of life was measured through a standard scale with scores from 0 to 100. Participants’ global quality of life mean was 59 + 17.8. The quality-of-life dimensions with the highest scores were sexual function, satisfaction with the healthcare provider, and satisfaction with life. The highest quality-of-life scores were obtained by participants who received antiretroviral therapy, had health insurance, lower symptoms of depression, low frequency and intensity of symptoms, and no prior reports of sexual abuse. Eight variables explained 53% of the variability of the global quality of life. Conclusions: Those receiving antiretroviral therapy and who report fewer symptoms best perceived their quality of life. Implications for practice: Healthcare providers, especially nursing professional face a challenge in caring to alleviate symptoms and contribute to improving the quality of life of their patients. Antecedente: Hoy en día se considera el VIH como una enfermedad crónica; por tanto,la calidad de vida es una meta importante de alcanzar en las personas que viven y conviven con el virus. Objetivos: Medir la calidad de vida en personas que viven con el virus del sida y establecer la relación con variables sociodemográficas y clínicas. Métodos: Estudio transversal, descriptivo, con muestra no probabilística de 137 personas con VIH que asistieron a tres instituciones de salud de Cali, Colombia. La calidad de vida se midió con el instrumento Hiv/Aids-Targeted Quality of Life (HAT-QoL). El análisis descriptivo incluyó los cálculos de promedio y desviación estándar. Para determinar las variables candidatas se utilizaron la prueba t de Student y la correlación de Pearson. La variable respuesta en la regresión lineal múltiple fue el puntaje de calidad de vida. Resultados: De los encuestados27% eran mujeres y 3% transgéneros; la edad promedio fue 35 + 10.2 años; 88% tenían algún tipo de seguro de salud; 27% con diagnóstico de Sida y 64% con tratamiento antirretroviral en el momento del estudio. La calidad de vida se midió con una escala estandarizada de 0 a 100; el promedio de calidad de vida global fue de 59 + 17.8; las dimensiones de calidad de vida que mayor puntaje obtuvieron fueron la función sexual, la satisfacción con el proveedor de cuidados de salud y la satisfacción con la vida. Los puntajes más altos en calidad de vida los obtuvieron personas que recibieron tratamiento antirretroviral, con acceso a algún seguro de salud, menor sintomatología depresiva, baja frecuencia e intensidad de síntomas y sin antecedentes de abuso sexual. Ocho variables explicaron 53% de la variabilidad de la calidad de vida. Conclusión: Las personas que reciben tratamiento antirretroviral y que informan menos síntomas son quienes mejor perciben su calidad de vida. Implicaciones para la práctica. Los proveedores de salud especialmente los profesionales de enfermería tienen un reto en el cuidado para aliviar los síntomas y hacer un aporte a la calidad de vida de los pacientes

    Detection and Quantification of HspX Antigen in Sputum Samples Using Plasmonic Biosensing : Toward a Real Point-of-Care (POC) for Tuberculosis Diagnosis

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    Advancements that occurred during the last years in the diagnosis of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis infection, have prompted increased survival rates of patients. However, limitations related to the inefficiency of an early detection still remain; some techniques and laboratory methods do not have enough specificity and most instruments are expensive and require handling by trained staff. In order to contribute to a prompt and effective diagnosis of tuberculosis, we report the development of a portable, user-friendly, and low-cost biosensor device for its early detection. By using a label-free surface plasmon resonance (SPR) biosensor, we have established a direct immunoassay for the direct detection and quantification of the heat shock protein X (HspX) of Mtb, a well-established biomarker of this pathogen, directly in pretreated sputum samples. The method relies on highly specific monoclonal antibodies that are previously immobilized on the plasmonic sensor surface. This technology allows for the direct detection of the biomarker without amplification steps, showing a limit of detection (LOD) of 0.63 ng mL-1 and a limit of quantification (LOQ) of 2.12 ng mL-1. The direct analysis in pretreated sputum shows significant differences in the HspX concentration in patients with tuberculosis (with concentration levels in the order of 116-175 ng mL-1) compared with non-tuberculosis infected patients (values below the LOQ of the assay)

    Iron deprivation enhances transcriptional responses to in vitro growth arrest of Mycobacterium tuberculosis

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    The establishment of Mycobacterium tuberculosis (Mtb) long-term infection in vivo depends on several factors, one of which is the availability of key nutrients such as iron (Fe). The relation between Fe deprivation inside and outside the granuloma, and the capacity of Mtb to accumulate lipids and persist in the absence of growth is not well understood. In this context, current knowledge of how Mtb modifies its lipid composition in response to growth arrest, depending on iron availability, is scarce. To shed light on these matters, in this work we compare genome-wide transcriptomic and lipidomic profiles of Mtb at exponential and stationary growth phases using cultures with glycerol as a carbon source, in the presence or absence of iron. As a result, we found that transcriptomic responses to growth arrest, considered as the transition from exponential to stationary phase, are iron dependent for as many as 714 genes (iron-growth interaction contrast, FDR <0.05), and that, in a majority of these genes, iron deprivation enhances the magnitude of the transcriptional responses to growth arrest in either direction. On the one hand, genes whose upregulation upon growth arrest is enhanced by iron deprivation were enriched in functional terms related to homeostasis of ion metals, and responses to several stressful cues considered cardinal features of the intracellular environment. On the other hand, genes showing negative responses to growth arrest that are stronger in iron-poor medium were enriched in energy production processes (TCA cycle, NADH dehydrogenation and cellular respiration), and key controllers of ribosomal activity shut-down, such as the T/A system mazE6/F6. Despite of these findings, a main component of the cell envelope, lipid phthiocerol dimycocerosate (PDIM), was not detected in the stationary phase regardless of iron availability, suggesting that lipid changes during Mtb adaptation to non-dividing phenotypes appear to be iron-independent. Taken together, our results indicate that environmental iron levels act as a key modulator of the intensity of the transcriptional adaptations that take place in the bacterium upon its transition between dividing and dormant-like phenotypes in vitro

    Development of a genetic tool for functional screening of anti-malarial bioactive extracts in metagenomic libraries

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    BACKGROUND: The chemical treatment of Plasmodium falciparum for human infections is losing efficacy each year due to the rise of resistance. One possible strategy to find novel anti-malarial drugs is to access the largest reservoir of genomic biodiversity source on earth present in metagenomes of environmental microbial communities. METHODS: A bioluminescent P. falciparum parasite was used to quickly detect shifts in viability of microcultures grown in 96-well plates. A synthetic gene encoding the Dermaseptin 4 peptide was designed and cloned under tight transcriptional control in a large metagenomic insert context (30 kb) to serve as proof-of-principle for the screening platform. RESULTS: Decrease in parasite viability consistently correlated with bioluminescence emitted from parasite microcultures, after their exposure to bacterial extracts containing a plasmid or fosmid engineered to encode the Dermaseptin 4 anti-malarial peptide. CONCLUSIONS: Here, a new technical platform to access the anti-malarial potential in microbial environmental metagenomes has been developed

    La interacción de procesos hidrológicos, químicos y microbiológicos en la formación de películas flotantes ricas en hierro en ambientes acuáticos de pH circumneutro

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    17 páginas.-- 3 figuras.-- 4 tablas.-- 53 referencias.-- Postprint (Versión editorial)[EN]: The direct contribution of microbial activity to the formation of iron-oxide minerals is difficult to prove in wetlands due to the high reactivity of solid iron phases with different compounds and the variety of redox processes that may occur at each oxic-anoxic boundary. Here, we propose an explanation for the formation of iron-oxide films in wetlands and groundwater seepage areas fed by sandy aquifers based on the interaction of hydrological, chemical and microbiological processes under circumneutral conditions. The presence of a floating iron-oxide film was found to create a boundary at the air-water interface that maintains a suboxic and slightly acidic environment below the film compared with the environments obtained in other free-film wetland areas. The water trapped below this film had an average pH of 6.1, was particularly poor in O2, HCO–3, Na+, Ca2+, Mg2+, K+, and Tot-S, and has high concentrations of Tot-P, Tot-Fe, NH+4 and Zn. The formation of a floating iron-oxide film was reproduced under anaerobic conditions after progressive enrichment through the incubation of natural sediment samples in the laboratory. Heterotrophic bacteria belonging to the genus Enterobacter were the dominant bacteria in the enrichments that resulted in the formation of a floating iron-oxide film. The X-ray diffraction patterns showed that the presence of two-line ferrihydrite was common to the iron-oxide films collected in both the natural environment and the laboratory cultures, whereas other iron-oxides (goethite and low-crystalline lepidocrocite) were observed only in the natural environment. This study highlights the role of ubiquitous bacteria, which are generally considered unimportant participants in iron-transformation processes in the environment, and the contribution of both biological and non-biological processes to iron oxidation in natural systems under circumneutral conditions.[ES]: En los humedales, es difícil probar que la actividad microbiana sea la responsable de la formación de óxido de hierro mineral debido, tanto a la gran reactividad del hierro en fase sólida con diferentes sustancias, como a la variedad de procesos redox que pueden ocurrir en cada interfase óxica-anóxica. El presente trabajo propone una explicación, basada en la interacción de procesos hidrológicos, químicos y microbiológicos en condiciones circumneutras, para explicar la formación de un film de óxido de hierro en humedales y manaderos donde aflora agua subterránea proveniente de acuíferos de arenas silíceas. Además, la presencia de un film de óxido de hierro que flota sobre la interfase agua-aire genera condiciones subóxicas y ligeramente ácidas en el agua que queda atrapada debajo, y que son muy distintas a otras zonas libres de film en el mismo humedal. Este agua atrapada bajo el film se caracterizó por presentar un pH medio de 6.1, una menor concentración de O2, HCO–3, Na+, Ca2+, Mg2+, K+, y S total, pero una mayor riqueza en P total, Fe total, NH+4 y Zn. La formación de un film flotante de óxido de hierro se reprodujo en el laboratorio, en condiciones anaeróbicas, tras el enriquecimiento progresivo de las muestras del sedimento natural que habían sido incubadas. En dichos enriquecimientos, donde se produjeron films flotantes de óxido de hierro, la bacteria dominante perteneció al género Enterobacter. Mediante difracción por rayos X, se encontró ferrihidrita con estructura en doble cadena, tanto en el film de muestras naturales como de cultivos de laboratorio. Además se encontraron otros tipos de óxidos minerales (goetita y lepidocrocita de pobre cristalización) sólo en las muestras naturales de film. El presente estudio muestra la relevancia de bacterias ubicuas, hasta ahora consideradas sin importancia en procesos naturales de transformación del hierro, y la participación tanto de procesos bióticos como abióticos en la oxidación del hierro en sistemas naturales sometidos a condiciones circumneutras.We are grateful to Han Golterman for his support and suggestions. We thank Lotte Fleskens and Christien van der Zwart for collaborating with the sediment collection and P-fractionation at the laboratory. This study was partially supported by the Spanish Ministry of Education and Science (CGL2004-03927-C02-01/BOS)Peer reviewe

    A 7-item version of the fatigue severity scale has better psychometric properties among HIV-infected adults : an application of a Rasch model

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    Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Purpose: To examine the psychometric properties of the 9-item Fatigue Severity Scale (FSS) using a Rasch model application. Methods: A convenience sample of HIV-infected adults was recruited, and a subset of the sample was assessed at 6-month intervals for 2 years. Socio-demographic, clinical, and symptom data were collected by self-report questionnaires. CD4 T-cell count and viral load measures were obtained from medical records. The Rasch analysis included 316 participants with 698 valid questionnaires. Results: FSS item 2 did not advanced monotonically, and items 1 and 2 did not show acceptable goodness-of-fit to the Rasch model. A reduced FSS 7-item version demonstrated acceptable goodness-of-fit and explained 61.2% of the total variance in the scale. In the FSS-7 item version, no uniform Differential Item Functioning was found in relation to time of evaluation or to any of the socio-demographic or clinical variables. Conclusion: This study demonstrated that the FSS-7 has better psychometric properties than the FSS-9 in this HIV sample and that responses to the different items are comparable over time and unrelated to socio-demographic and clinical variables
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