120 research outputs found

    Rhodoliths and rhodolith beds

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    Rhodolith (maërl) beds, communities dominated by free living coralline algae, are a common feature of subtidal environments worldwide. Well preserved as fossils, they have long been recognized as important carbonate producers and paleoenvironmental indicators. Coralline algae produce growth bands with a morphology and chemistry that record environmental variation. Rhodoliths are hard but often fragile, and growth rates are only on the order of mm/yr. The hard, complex structure of living beds provides habitats for numerous associated species not found on otherwise entirely sedimentary bottoms. Beds are degraded locally by dredging and other anthropogenic disturbances, and recovery is slow. They will likely suffer severe impacts worldwide from the increasing acidity of the ocean. Investigations of rhodolith beds with scuba have enabled precise stratified sampling that has shown the importance of individual rhodoliths as hot spots of diversity. Observations, collections, and experiments by divers have revolutionized taxonomic studies by allowing comprehensive, detailed collection and by showing the large effects of the environment on rhodolith morphology. Facilitated by in situ collection and calibrations, corallines are now contributing to paleoclimatic reconstructions over a broad range of temporal and spatial scales. Beds are particularly abundant in the mesophotic zone of the Brazilian shelf where technical diving has revealed new associations and species. This paper reviews selected past and present research on rhodoliths and rhodolith beds that has been greatly facilitated by the use of scuba

    Damage on a Main Gas Pipeline Due to Landslide of Soils Derived From Volcanic Ashes in Colombia

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    In December 2011 a great proportion slope failed affecting the main gas pipeline (20” diameter) that supplies Colombia’s southwest area. The landslide involved materials formed by soils derived from volcanic ashes and residual soils, typical in Colombia’s central zone, which acquired great energy flowing in an avalanche through the natural watercourse. The avalanche generated soil erosion over the torrent banks, generating the watercourse deepening and the deterioration of adjacent slopes over which the pipeline runs. There were identified as landslides triggering aspects the atypical raining period due to “La Niña” climatic phenomenon and the soils removal at the slope base due to a minor stream. The article contains an analysis based on the characterization of this particular soil and the main landslide and avalanche incidence on the adjacent slopes stability. Additionally, it presents the results of the numerical soil-pipe interaction analysis with finite elements models that was completed to define and design the stabilization works

    Introduction To The Special Edition On Latina/o/x Prek-12 Education

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    Listening to Latina/o/x Voices: Maximizing Opportunities and Minimizing Obstacles in Distinct Educational Context

    Spatial distribution modeling for invasive exotic trees in the Pre-Delta National Park (Entre Ríos, Argentina)

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    Se estudió la distribución espacial de árboles exóticos invasores (AEI) en el Parque Nacional Pre-Delta (PNPD-Entre Ríos, Argentina) mediante el empleo de técnicas de muestreo a distancia. Se modeló la distribución potencial mediante la técnica de interpolación Kriging. Se comparó la cartografía generada con un mapa de zonificación del PNPD y con cartografía de unidades ambientales identificadas en función de un gradiente topográfico. Se registraron datos estructurales del bosque, fenológicos de los árboles y de las acciones de control por parte del personal del PNPD, a fin de caracterizar los procesos de invasión. Se obtuvo cartografía de la distribución potencial de Melia azedarach L., Broussonetia papyrifera (L.) L'Hér. ex Vent., Ligustrum lucidum W.T. Aiton, Brachychiton populneus (Schott & Endl.) R. Br., Fraxinus sp. L. y Morus alba L. Esta última resultó ser dominante en el PNPD en los tres sectores estudiados (barrancas, islas y zona alta). En cuanto a las acciones de manejo de especies exóticas de los agentes del PNPD, cerca del 50% de los ejemplares de M. alba sujeto a aplicaciones de control mecánico (técnica de anillado) presentaron rebrotes, indicando su alta capacidad de supervivencia.Spatial distribution of alien trees was studied on Pre-Delta National Park (PNPD-Entre Ríos, Argentina), by distance sampling techniques. Potential distribution was modelled by Kriging interpolation technique. Generated maps were overlapped with PNPD zonification map and environmental units map. We recorded forest structural data, tree phenology and tree control management actions, in order to characterize the processes of invasion. We obtained maps of potential distribution of Melia azedrach, Broussonetia papyrifera, Ligustrum lucidum, Brachychiton populneus, Fraxinus sp. and Morus alba L. The latter was the dominant species in all studied sectors (cliffs, islands and highlands). As for the management actions carried out with trees of the PNPD, about 50% of the specimens of M. alba subjected to mechanical control (banding technique) showed regrowth, indicating its high survival capacity.Fil: Torresin, Jerónimo A.. Provincia de Misiones. Ministerio de Ecología; ArgentinaFil: Zamboni, L. Pamela. Universidad Autonoma de Entre Rios. Facultad de Ciencia y Tecnologia; ArgentinaFil: Sione, Walter F.. Universidad Autonoma de Entre Rios. Facultad de Ciencia y Tecnologia; Argentina. Universidad Nacional de Luján; ArgentinaFil: Rodriguez, Estela Elizabeth. Universidad Autonoma de Entre Rios. Facultad de Ciencia y Tecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Aceñolaza, Pablo Gilberto. Universidad Autonoma de Entre Rios. Facultad de Ciencia y Tecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin

    Observations About the Seismic Response of RC Buildings in Mexico City

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    Over 2000 buildings were surveyed by members of the Colegio de Ingenieros (CICM) and Sociedad Mexicana de Ingenieria Estructural (SMIE) in Mexico City following the Puebla-Morelos Earthquake of 2017. This inventory of surveyed buildings included nearly 40 collapses and over 600 buildings deemed to have structural damage. Correlation of damage with peak ground acceleration (PGA), peak ground velocity (PGV), predominant spectral period, building location, and building properties including height, estimated stiffness, and presence of walls or retrofits was investigated for the surveyed buildings. The evidence available suggests that (1) ground motion intensity (PGV) drove the occurrence of damage and (2) buildings with more infill and stiff retrofit systems did better than other buildings

    Efficacy and outcomes of ramucirumab and docetaxel in patients with metastatic non-small cell lung cancer after disease progression on immune checkpoint inhibitor therapy: Results of a monocentric, retrospective analysis

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    Current first-line standard therapy for metastatic non-small cell lung cancer without driver mutations involves chemotherapy and immunotherapy combination. Prior to the advent of immune checkpoint inhibition, REVEL, a randomized phase III trial demonstrated improved progression-free and overall survival with ramucirumab and docetaxel (ram+doc) in patients who failed platinum-based first-line therapy. Long-term outcomes related to second-line ramucirumab and docetaxel after first-line immunotherapy exposure remain unknown. We analyzed outcomes for 35 patients from our center whom received ramucirumab and docetaxel following disease progression on chemotherapy and immunotherapy combination. Median progression-free survival among patients who received ram+doc after exposure to immunotherapy was 6.6 months (95% CI = 5.5 to 14.9 months; p<0.0001), and median overall survival was 20.9 months (95% CI = 13.4 months to infinity; p<0.0001). These outcomes suggest that there may a synergistic benefit to combining chemotherapy with anti-angiogenic therapy after immunotherapy exposure. Future analyses should be evaluated prospectively and among a larger patient subset

    No Place Like Home: Examining a Bilingual-Bicultural, Self-Run Substance Abuse Recovery Home for Latinos

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    Latinos often do not seek substance abuse services, and this might be correlated to the lack of culturally-modified substance abuse treatment approaches. Oxford House is the largest self-help residential recovery program in the U.S., yet few Latinos are among their current residents. In an effort to change this, bilingual-bicultural recovery homes were recently developed for Latinos. This article describes the process in opening these bilingual-bicultural houses and how sociocultural factors such as the family, simpatía, and gender roles impacted the living environment of these houses. In addition, language is highlighted as a key factor to the comfort and success of Latinos living in Oxford Houses. Based on these experiences, the article addresses several obstacles/barriers that impacted this process and possible feasible solutions to these challenges. One challenge is the Latino family system. While this may provide a supportive, cost-effective option for some; it can also perpetuate a cycle of codependence and substance abuse

    High resolution human leukocyte antigen (HLA) class I and class II allele typing in Mexican mestizo women with sporadic breast cancer: case-control study

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    <p>Abstract</p> <p>Background</p> <p>The development of breast cancer is multifactorial. Hormonal, environmental factors and genetic predisposition, among others, could interact in the presentation of breast carcinoma. Human leukocyte antigen (HLA) alleles play an important role in immunity (cellular immunity) and may be important genetic traits. HLAAllele-specific interaction has not been well established. Recently, several studies had been conducted in order to do so, but the results are controversial and in some instances contradictory.</p> <p>Methods</p> <p>We designed a case-control study to quantify the association of HLA class I and II genes and breast cancer. HLA typing was performed by high resolution sequence-specific oligotyping after DNA amplification (PCR-SSOP) of 100 breast cancer Mexican mestizo patients and 99 matched healthy controls.</p> <p>Results</p> <p>HLA-A frequencies that we were able to observe that there was no difference between both groups from the statistical viewpoint. HLA-B*1501 was found three times more common in the case group (OR, 3.714; <it>p </it>= 0.031). HLA-Cw is not a marker neither for risk, nor protection for the disease, because we did not find significant statistical differences between the two groups. DRB1*1301, which is expressed in seven cases and in only one control, observing an risk increase of up to seven times and DRB1*1602, which behaves similarly in being present solely in the cases (OR, 16.701; 95% CI, 0.947 – 294.670). DQ*0301-allele expression, which is much more common in the control group and could be protective for the presentation of the disease (OR, 0.078; 95% CI, 0.027–0.223, <it>p </it>= 0.00001).</p> <p>Conclusion</p> <p>Our results reveal the role of the MHC genes in the pathophysiology of breast cancer, suggesting that in the development of breast cancer exists a disorder of immune regulation. The triggering factor seems to be restricted to certain ethnic groups and certain geographical regions since the relevant MHC alleles are highly diverse. This is the first study in Mexican population where high resolutions HLA typing has been performed in order to try to establish an association with malignancy.</p
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