The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Rural Rio de Janeiro, Dept Biol Anim, Lab Ecol Peixes, Campus Seropedica, Seropedica, RJ, BrazilUniv Fed Rural Rio de Janeiro, Dept Ciencias Meio Ambiente, Campus Tres Rios, Seropedica, RJ, BrazilUniv Fed Sao Paulo, Inst Mar, Lab Ecol & Conservacao Marinha, Campus Baixada Santista, Santos, SP, BrazilLaboratório de Ecologia e Conservação Marinha, Instituto do Mar, Universidade Federal de São Paulo, Campus Baixada Santista, Santos, SP, BrazilWeb of Scienc

The dominance of desmids in tropical monomictic lakes (SE Brazil)

Disturbance is a concept used to explain the structure of communities. This concept emphasizes the effects of disturbance on the "break" of biomass stability in stable environments and the opportunities for the development of other species. The major disturbances in natural warm monomictic lakes include the contrasting effects of seasonal changes and long-term in thermal stability, as well as short-term changes in the mixing layer. This study investigated the effects of disturbance and abiotic environmental factors on the biomass of desmids, based on samples collected monthly from January 2002 through December 2006 in the limnetic region of two natural lakes, Carioca (small and shallow) and Dom Helvécio (large and deep), located in Rio Doce State Park, Minas Gerais State,south east Brazil.At Lake Dom Helvécio,the extensive banks of aquatic macrophytes, the lake's dendritic shape and the period of clear water produced higher richness values and facilitated the occurrence of relatively large (maximum linear dimension >20 µm) desmid species, primarily species belonging to Staurastrum and Staurodesmus. In contrast, less richness and a dominant group of relatively small (maximum linear dimension <20 µm) desmid species, especially species belonging to the genus Cosmarium, were observed at Lake Carioca in conjunction with a sparse macrophyte cover. The lakes showed a seasonal thermal stratification characterized by high temperature (25-32ºC), thermal stability and higher desmid biomass. The stability of the epilimnetic desmid biomass was an indicator of the adaptive flexibility of the desmid species and the capacity of the biomass to recover after the mixing period.La perturbación es un concepto utilizado para explicar la estructura de las comunidades, con énfasis en sus efectos sobre la "ruptura" de la estabilidad de la biomasa en ambientes estables y sobre las oportunidades para el desarrollo de nuevas especies. Entre las perturbaciones más importantes encontradas en lagos naturales monomíticos destaca el efecto de las variaciones estacionales y de largo plazo en la estabilidad térmica, así como los cambios a corto plazo en la profundidad de la mezcla. En este trabajo se describe el efecto de la estratificación y mezcla del lago así como de otros factores abióticos sobre la biomasa de desmidiáceas en lagos tropicales. Los muestreos se realizaron mensualmente entre enero de 2002 y diciembre de 2006 en la región pelágica de dos lagos naturales monomíticos cálidos, Carioca (pequeño y poco profundo) y Dom Helvécio (grande y bastante profundo) ubicados en el Parque Estadual do Rio Doce (Estado Minas Gerais, SE Brasil). En el lago Dom Helvécio, las grandes acumulaciones de macrófitas acuáticas, la forma dendrítica del lago y el período de aguas transparentes influyeron de forma sinérgica en una mayor riqueza de especies y de tamaños grandes, mayores de 20 µm, siendo principalmente especies de Staurastrum y Staurodesmus. Sin embargo, en el Lago Carioca se observó una menor riqueza y el dominio de desmidiáceas de pequeño tamaño (<20 µm), especialmente Cosmarium. Este último lago presentó también una cobertura escasa de macrófitas. Los lagos mostraron un patrón estacional caracterizado, durante la estratificación térmica, por el aumento de la temperatura (25-32ºC), estabilidad térmica y mayor biomasa de desmidiáce. La estabilidad de la biomasa epilimnética fue indicativo de una flexibilidad adaptiva y recuperación después del período de mezcla

Saponins from edible spears of wild asparagus inhibit AKT, p70S6K, and ERK signalling, and induce apoptosis through G0/G1 cell cycle arrest in human colon cancer HCT-116 cells

41 Páginas, 6 Figuras, 1 TablaThe effects of steroidal saponins from edible spears of wild triguero Huetor-Tajar asparagus on some of the oncogenic molecular pathways that are affected in human colon cancer cells were investigated. Reverse-phase chromatography and a new HPLC-MS method were used to respectively isolate and analyse the composition of the steroidal saponins. They were resistant to simulated digestion and, when in contact with HTC-116 human colon carcinoma cells, interfered with extracellular signal-regulated kinase (ERK), S6 kinase (p70S6K, mTOR), and RAC-alpha serine/threonine-protein kinase (AKT) pathways by a downregulation of these proteins. The expressions of cyclins D, E, and A were also decreased, leading to G0/G1 cell cycle arrest. In addition, these steroidal saponins induced typical features of apoptosis by the promotion of caspase-3 activity, poly(ADP-ribose) polymerase 1 (PARP-1) cleavage, and DNA fragmentation. These results offer potential dietary intervention strategy against human colon cancer cells.This study was supported by grants AGL2011-29632 and AGL2011-29008 funded by MICINN. S.L. acknowledges financial support from the Spanish MINECO (JCI-2012-13084, Juan de la Cierva) and the Spanish Research Council (CSIC)/JAE-doc Program (JAEDOC089), a contract cofounded by the European Social Fund (ESF).Peer reviewe

Non-Oberbeck-Boussinesq effects in turbulent thermal convection in ethane close to the critical point

As shown in earlier work (Ahlers et al., J. Fluid Mech. 569, p.409 (2006)), non-Oberbeck Boussinesq (NOB) corrections to the center temperature in turbulent Rayleigh-Benard convection in water and also in glycerol are governed by the temperature dependences of the kinematic viscosity and the thermal diffusion coefficient. If the working fluid is ethane close to the critical point the origin of non-Oberbeck-Boussinesq corrections is very different, as will be shown in the present paper. Namely, the main origin of NOB corrections then lies in the strong temperature dependence of the isobaric thermal expansion coefficient \beta(T). More precisely, it is the nonlinear T-dependence of the density \rho(T) in the buoyancy force which causes another type of NOB effect. We demonstrate that through a combination of experimental, numerical, and theoretical work, the latter in the framework of the extended Prandtl-Blasius boundary layer theory developed in Ahlers et al., J. Fluid Mech. 569, p.409 (2006). The latter comes to its limits, if the temperature dependence of the thermal expension coefficient \beta(T) is significant.Comment: 18 pages, 15 figures, 3 table

A novel model of care for simplified testing of HBV in African communities during the COVID-19 pandemic in Spain

Epidemiology; Health services; Viral hepatitisEpidemiologia; Serveis de salut; Hepatitis viralEpidemiología; Servicios de salud; Hepatitis viralChronic hepatitis B virus (HBV) infection is a major public health threat for migrant populations in Spain and efforts to scale up testing are needed to reach the WHO elimination targets. The Hepatitis B Virus Community Screening and Vaccination in Africans (HBV-COMSAVA) study aims to use point-of-care testing and simplified diagnostic tools to identify, link to care, or vaccinate African migrants in Barcelona during the COVID-19 pandemic. From 21/11/20 to 03/07/2021, 314 study participants were offered HBV screening in a community clinic. Rapid tests for HBsAg screening were used and blood samples were collected with plasma separation cards. Patients received results and were offered: linkage to specialist care; post-test counselling; or HBV vaccination in situ. Sociodemographic and clinical history were collected and descriptive statistics were utilized. 274 patients were included and 210 (76.6%) returned to receive results. The HBsAg prevalence was 9.9% and 33.2% of people had evidence of past resolved infection. Overall, 133 required vaccination, followed by post-test counselling (n = 114), and linkage to a specialist (n = 27). Despite the COVID-19 pandemic, by employing a community-based model of care utilizing novel simplified diagnostic tools, HBV-COMSAVA demonstrated that it was possible to diagnose, link to care, and vaccinate African migrants in community-based settings.This study was carried out by ISGlobal with competitive funding through the Gilead Sciences global HBV-CARE program (IN-ES-988–5799)

Analysis of Strict Social Isolation (SSI-Lockdown) Measures Impacts on Atmospheric Pollutant Emissions and Health Risks on Roads with Intense Vehicle Flow in the City of Fortaleza-Ceara/Brazil

In early 2020, governments of many countries adopted strict social isolation (SSI) measures to contain the spread of the SARS-CoV-2 Disease (COVID-19). Thus, the present work aimed to evaluate the influence of those SSI measures on atmospheric pollutants emissions and their potential health risks in the city of Fortaleza - Ceará. To this end, static and dynamic analyses were carried out in order to investigate the levels of some atmospheric pollutants found in four main avenues during SSI and post-SSI periods.  In addition, some health indicators were investigated by analyzing potential Particulate Matter (PM) deposition in the respiratory tract of populations exposed to those environments. Our results for both dynamic and static analyses show that all pollutant concentrations from those avenues displayed an increase between SSI and the post-SSI period. The total PM2.5 dose deposited in the respiratory tract and potential total PM10 respiratory deposition showed increases between the SSI and post-SSI periods. The inhaled-dose numbers also showed considerable increases for all avenues when comparing SSI and post-SSI periods. According to our results, SSI contributed to decreases in atmospheric pollutant emissions, in potential particulate matter respiratory tract deposition and, consequently, in the inhaled particulate matter dose

Allylic Oxidation of Alkenes Catalyzed by a Copper−Aluminum Mixed Oxide

A strategy for the allylic oxidation of cyclic alkenes with a copper−aluminum mixed oxide as catalyst is presented. The reaction involves the treatment of an alkene with a carboxylic acid employing tert-butyl hydroperoxide as the oxidant. In all cases, the corresponding allylic esters are obtained. When L-proline is employed, the allylic alcohol or ketone is obtained. The oxidation of cyclohexene and valencene has been optimized by design of experiments (DoE) statistical methodology