El proceso de recuperación de Residuos de Aparatos Eléctricos y Electrónicos (raee) crece día a día. Desde el punto de vista académico y empresarial, este presenta una notable importancia económica, ...ambiental y tecnológica, y su estudio en nuestro país aún está en su etapa inicial. El presente estudio tiene como objetivo la validación y entendimiento de un modelo de logística inversa para la recuperación de raee a partir del diseño y la construcción de un modelo de simulación continua basado en la perspectiva del pensamiento sistémico soportado con la dinámica de sistemas; Las proyecciones de este estudio se construyeron con base en la información del proceso de recuperación en forma artesanal que utilizan empresas de la región, así como empresas del sector que poseen niveles aceptables de tecnología para realizar las actividades de recuperación. Puntualmente, se tomó como referencia una empresa del sector, que presenta el proceso de recuperación del plástico pet, el cual es adaptable a cualquier proceso de recuperación de diferentes tipos de plástico. Esta primera aproximación permitió iniciar el proceso para la formulación de un sistema de logística inversa para el tratamiento de los residuos que generan los aparatos de las tecnologías de la información. Los resultados obtenidos en el modelo propuesto muestran comportamientos coherentes y este puede ser usado en diferentes escenarios y en otros procesos productivos para la recuperación de los raee. El estudio del sistema para la Recuperación de Aparatos Eléctricos y Electrónicos presenta altos niveles de variabilidad e incertidumbre, que lo convierten en algo complejo; esto obliga a la utilización de herramientas consideradas robustas, como la dinámica de sistemas, para su análisis.
Se ha analizado, mediante un diseño cuasi-experimental con 19 sanitarios (33.7 ± 5.1 años), la importancia de la condición física, cognitiva y el rendimiento al portar un equipo de protección con ...mascarilla quirúrgica durante situaciones de entrenamiento en contextos significativos de intervención militar. Se midieron la frecuencia cardíaca y su variabilidad, los niveles de glucosa, la termorregulación, la fuerza explosiva y el esfuerzo percibido en tareas de rendimiento motor específicas (tapping test, torniquete, municionamiento), y de rendimiento cognitivo y decisional (triaje). Los resultados indican diferencias significativas (p < 05) en función de la condición física (glucemia y fuerza explosiva), del género (fuerza explosiva y torniquete), del hábito tabáquico (esfuerzo percibido) y del cuerpo de pertenencia (nivel de glucemia) en el grupo de estudio. Como conclusión, se destaca la importancia del entrenamiento físico y psicológico para la mejora de la respuesta operativa en situaciones sanitario-militares que requieren el uso de mascarilla quirúrgica.
Un estilo de vida activo puede prevenir la mayoría de enfermedades crónicas. El objetivo de este estudio es conocer las preferencias de tipos de actividad física en una población de alto riesgo ...cardiovascular, lo que permitirá optimizar el consejo profesional en poblaciones similares. La muestra de estudio está formada por 326 personas mayores, obesas y con síndrome metabólico del estudio PREDIMED-Plus de Málaga, a las que se preguntó en la visita basal qué tipo de ejercicio realizan. Las respuestas se estandardizaron y clasificaron. El 47,5 % (155) realiza caminatas deprisa. Tras la caminata, la “Calistenia, esfuerzo ligero o moderado” es el tipo de ejercicio más referido. En conclusión, las personas que refieren realizar algún tipo de ejercicio prefieren actividades de intensidad ligera a moderada, sencillas y/o dirigidas por un monitor. Algunos participantes refieren practicar ejercicio de mayor intensidad y complejidad, pudiendo ser una recomendación factible para personas de características similares.
Analizamos 103 censos de vegetación de la Estepa Magallánica Seca, un área de 12000 km2 de estepas graminosas semiáridas en el SE de la Patagonia. Los objetivos del presente trabajo fueron ampliar el ...relevamiento de vegetación de la región, clasificar las principales comunidades, interpretarlas en función de Modelos de Estados y Transiciones (MEyT), cartografiar su distribución espacial y buscar evidencias de posibles transiciones mediante análisis de contrastes de alambrado. El análisis de conglomerados definió 10 comunidades vegetales, algunas de las cuales no estaban contempladas en el MEyT previo, por lo que fue necesario generar un nuevo MEyT. Este modelo incluye transiciones ya descriptas previamente, en las que la erosión expone horizontes B t y genera condiciones favorables a Estepas Subarbustivas, pero además, otras en las cuales se acumulan sedimentos que favorecen a Pappostipa chrysophylla, una gramínea psamófila invasora. Tres estados que se diferenciaban en el modelo anterior por cambios reversibles de cobertura de pastos cortos fueron combinados para reflejar solamente transiciones irreversibles. Para la cartografía se trazaron polígonos alrededor de cada censo sobre imágenes satelitales LANDSAT, se combinaron de acuerdo con el análisis de agrupamiento, se obtuvieron firmas espectrales, se clasificaron y se agruparon las clases del mapa en cinco estados. La precisión del mapa fue mayor al 61%. El 39% del área correspondió a Coironales en buena condición de conservación, dominantes al sur. Le siguen en importancia las Estepas Subarbustivas con P. chrysophylla (18%) y las Estepas Subarbustivas (15%), ambas degradadas. Los contrastes de alambrados evidenciaron transiciones que habían sido hipotetizadas en el modelo, como las que llevaron a Estepas Subarbustivas degradadas asociadas probablemente a un pastoreo de invernada intenso previo. El mapa y el MEyT que se presentan en este trabajo permiten interpretar mejor la dinámica de la Estepa Magallánica Seca, una de las áreas ecológicas más diversas y productivas de la Patagonia, que muestra extensas áreas degradadas. Estos pastizales deberían ser protegidos en el futuro, ya que no existen prácticamente áreas de conservación. En este sentido, toda la región debería ser conservada por medio de un manejo de cargas ganaderas moderadas y descansos que aseguren el mantenimiento de la biodiversidad, productividad y servicios ecosistémicos.
Mesonephric lesions in the female genital tract are uncommon, with those arising from the upper tract being much less frequent than those developing in the lower tract (mesonephric hyperplasia and ...carcinoma). The most common upper tract lesions include rete cyst/cystadenoma and female adnexal tumour of Wolffian origin (FATWO). The integration of morphological, immunohistochemical and molecular studies on FATWOs has enabled recognition of a novel entity, the STK11 adnexal tumour, which is often associated with Peutz–Jeghers syndrome (~50%) and frequently has a salivary gland morphology but an unknown origin. Similarly, ‘mesonephric‐like’ adenocarcinoma, an entity with striking similarities to mesonephric carcinoma but currently favoured to be of Müllerian derivation based on its association with other Müllerian tumours and molecular findings, has also been recently described, and may histologically mimic both FATWOs and STK11 adnexal tumours. In this review, we provide a historical overview of upper female genital tract mesonephric proliferations and discuss mesonephric lesions, STK11 adnexal tumour, mesonephric‐like adenocarcinoma, and mimickers, the most common being endometrioid carcinoma.
Female adenxal tumor of wolffian origin (A). STK11 adnexal tumour (B). Mesonephric‐like adenocarcinoma (C). Fallopian tube endometrioid carcinoma resembling FATWO (D).
Gene order is not random in eukaryotic chromosomes, and co-regulated genes tend to be clustered. The mechanisms that determine co-regulation of large regions of the genome and its connection with ...chromatin three-dimensional (3D) organization are still unclear however. Here we have adapted a recently described method for identifying chromatin topologically associating domains (TADs) to identify coexpression domains (which we term "CODs"). Using human normal breast and breast cancer RNA-seq data, we have identified approximately 500 CODs. CODs in the normal and breast cancer genomes share similar characteristics but differ in their gene composition. COD genes have a greater tendency to be coexpressed with genes that reside in other CODs than with non-COD genes. Such inter-COD coexpression is maintained over large chromosomal distances in the normal genome but is partially lost in the cancer genome. Analyzing the relationship between CODs and chromatin 3D organization using Hi-C contact data, we find that CODs do not correspond to TADs. In fact, intra-TAD gene coexpression is the same as random for most chromosomes. However, the contact profile is similar between gene pairs that reside either in the same COD or in coexpressed CODs. These data indicate that co-regulated genes in the genome present similar patterns of contacts irrespective of the frequency of physical chromatin contacts between them.
The ultimate goal of defining cancer specific precursors is to facilitate early detection and intervention before the development of invasive malignancy. Unlike other malignancies involving the ...female genital tract such as cervical or endometrial carcinomas, precursor lesions of ovarian carcinomas have not been well characterised, resulting in a failure to develop effective screening programs. Recent clinicopathological and molecular studies have provided new insight into the origin and pathogenesis of ovarian carcinomas. It has been shown that ovarian cancer is comprised of different tumour types differing not only in morphology, but also in pathogenesis, molecular alterations and clinical progression. A dualistic model of ovarian carcinogenesis has been proposed. Type I tumours which include low grade serous, low grade endometrioid, clear cell, mucinous carcinomas and Brenner tumours, are generally indolent and tend to be genetically stable, although clear cell carcinoma would probably belong to an intermediate category. They demonstrate a step-wise progression from a benign precursor such as a benign to borderline tumour or endometriosis and are characterised by genetic aberrations targeting specific cell signalling pathways. Type II tumours comprise high grade serous, high grade endometrioid, and undifferentiated carcinomas as well as malignant mixed mesodermal tumours. They are clinically aggressive and exhibit high genetic instability with frequent p53 mutations. Mounting evidence suggests that many high grade serous carcinomas originate from the epithelium of the distal fallopian tube, and that serous tubal intraepithelial carcinoma (STIC) represents the putative precursor of these neoplasms. Low grade serous carcinomas arise via transformation of benign and borderline serous tumours, thought to be derived from inclusion cysts originating from the ovarian surface or tubal epithelium. Recently it has been suggested that papillary tubal hyperplasia may be a putative precursor lesion for serous borderline tumours. Both endometrioid and clear cell carcinomas develop from endometriosis, via alterations affecting different genetic pathways. The origin of mucinous and transitional cell neoplasms is not well characterised, although new data suggest a possible origin from transitional cell nests present at the tubal-mesothelial junction. Likewise, the pathogenesis of carcinosarcomas is also not well established because of their rarity but there is accumulating evidence that the carcinomatous component determines the course of the disease and gives rise to the malignant mesenchymal component. This review discusses recent developments in the pathogenesis of ovarian carcinoma, with particular emphasis on the putative precursor lesions that give rise to the major histological subtypes. Recognition of these lesions is not only important in improving the understanding of ovarian carcinogenesis, but it will also influence our approach to prevent, detect and treat these tumours.
Identifying how R-loops are generated is crucial to know how transcription compromises genome integrity. We show by genome-wide analysis of conditional yeast mutants that the THO transcription ...complex, prevents R-loop formation in G1 and S-phase, whereas the Sen1 DNA-RNA helicase prevents them only in S-phase. Interestingly, damage accumulates asymmetrically downstream of the replication fork in sen1 cells but symmetrically in the hpr1 THO mutant. Our results indicate that: R-loops form co-transcriptionally independently of DNA replication; that THO is a general and cell-cycle independent safeguard against R-loops, and that Sen1, in contrast to previously believed, is an S-phase-specific R-loop resolvase. These conclusions have important implications for the mechanism of R-loop formation and the role of other factors reported to affect on R-loop homeostasis.
Recent observations have revealed massive galactic molecular outflows that may have the physical conditions (high gas densities) required to form stars. Indeed, several recent models predict that ...such massive outflows may ignite star formation within the outflow itself. This star-formation mode, in which stars form with high radial velocities, could contribute to the morphological evolution of galaxies, to the evolution in size and velocity dispersion of the spheroidal component of galaxies, and would contribute to the population of high-velocity stars, which could even escape the galaxy. Such star formation could provide in situ chemical enrichment of the circumgalactic and intergalactic medium (through supernova explosions of young stars on large orbits), and some models also predict it to contribute substantially to the star-formation rate observed in distant galaxies. Although there exists observational evidence for star formation triggered by outflows or jets into their host galaxy, as a consequence of gas compression, evidence for star formation occurring within galactic outflows is still missing. Here we report spectroscopic observations that unambiguously reveal star formation occurring in a galactic outflow at a redshift of 0.0448. The inferred star-formation rate in the outflow is larger than 15 solar masses per year. Star formation may also be occurring in other galactic outflows, but may have been missed by previous observations owing to the lack of adequate diagnostics.
Undifferentiated and dedifferentiated endometrial carcinomas are rare and highly aggressive subtypes of uterine cancer, not well characterized at a molecular level. To investigate whether ...dedifferentiated carcinomas carry molecular genetic alterations similar to those of pure undifferentiated carcinomas, and to gain insight into the pathogenesis of these tumors, we selected a cohort of 18 undifferentiated endometrial carcinomas, 8 of them with a well-differentiated endometrioid carcinoma component (dedifferentiated endometrioid carcinomas), and studied them by immunohistochemistry and massive parallel and Sanger sequencing. Whole-exome sequencing of the endometrioid and undifferentiated components, as well as normal myometrium, was also carried out in one case. According to The Cancer Genome Atlas classification, we distributed 95% of the undifferentiated carcinomas in this series as follows: (a) hypermutated tumors with loss of any mismatch repair protein expression and microsatellite instability (eight cases, 45%); (b) ultramutated carcinomas carrying mutations in the exonuclease domain of POLE (two cases, 11%); (c) high copy number alterations (copy-number high) tumors group exhibiting only TP53 mutations and high number of alterations detected by FISH (two cases, 11%); and (d) low copy number alterations (copy-number low) tumors with molecular alterations typical of endometrioid endometrial carcinomas (five cases, 28%). Two of the latter cases, however, also had TP53 mutations and higher number of alterations detected by FISH and could have progressed to a copy-number high phenotype. Most dedifferentiated carcinomas belonged to the hypermutated group, whereas pure undifferentiated carcinomas shared molecular genetic alterations with copy-number low or copy-number high tumors. These results indicate that undifferentiated and dedifferentiated endometrial carcinomas are molecularly heterogeneous tumors, which may have prognostic value.
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