902 research outputs found
Diversidad genética en pacientes embarazadas seropositivas para el VIH-1 en la comunidad balear
Objetivo: El objetivo de este estudio es analizar la prevalencia de los diferentes subtipos del VIH-1 en pacientes gestantes de la Comunidad Balear. Métodos: Se incluyeron de forma retrospectiva todas las gestantes seropositivas para el VIH-1 genotipadas en el Servicio de Microbiología y la Unidad de Secuenciación del Hospital Universitario Son Dureta, entre los años 2005 y 2010, en total 45. Durante el seguimiento se realizó la cuantificación de la carga viral, el recuento de linfocitos T CD4+ y el genotipado mediante la secuenciación el gen pol del VIH-1. Las secuencias FASTA obtenidas fueron analizadas con la plataforma informática HIVDB Program de la Universidad de Stanford. Resultados: De las 45 gestantes incluidas en el estudio, 26 (57,8%) presentaban un subtipo B y 19 (42,2%) un subtipo no B, siendo más frecuentes las formas recombinantes (CRFs) (68,8%). Conclusión: La introducción de subtipos no B en la comunidad balear es importante y el análisis de estas variantes en la población embarazada es de gran utilidad para monitorizar la entrada en nuestro país de variantes nuevas con implicaciones epidemiológicas y terapéuticas.Aim: The aim of this study was to asses the prevalence of HIV-1 subtypes in pregnant women in the Balearic Community. Methods: We retrospectively included all HIV-1 seropositive pregnant women genotyped in the Service of Microbiology and the Sequencing Unit of the University Hospital Son Dureta between 2005 and 2010 (n=45). During the follow-up, quantification of viral load, CD4+ T lymphocytes count and genotyping of HIV-1 throw sequencing of pol gene, were performed. FASTA sequences were analyzed using the HIVDB Program of the Stanford University. Results: From a total of 45 HIV-1 seropositive women included, 26 (57.8%) were infected with clade B HIV- 1 whereas in the remaining 19 (42.2%,) sequencing studies shown a non-B viral subtype, being the circulating recombinant forms (CRFs) the most frequent (68.8% of the non-B subtypes). Conclusion: HIV-1 non-B subtypes have spread in our community. Analysis of these variants in the pregnant woman population could be a useful tool fo
Understanding the structure and reactivity of NiCu nanoparticles: An atomistic model
The structure of bimetallic NiCu nanoparticles (NP) is investigated as a function of their composition and size by means of Lattice MonteCarlo (LMC) and molecular dynamics (MD) simulations. According to our results, copper segregation takes place at any composition of the particles. We found that this feature is not size-dependent. In contrast, nickel segregation depends on the NP size. When the size increases, Ni atoms tend to remain in the vicinity of the surface and deeper. For smaller NPs, Ni atoms are located at the surface as well. Our results also showed that most of the metal atoms segregated at the surface area were found to decorate edges and/or form islands. Our findings agree qualitatively with the experimental data found in the literature. In addition, we comment on the reactivity of these nanoparticles.Fil: Quaino, Paola Monica. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belletti, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; ArgentinaFil: Shermukhamedov, S. A.. Kazan National Research Technological University; RusiaFil: Glukhov, D. V.. Kazan National Research Technological University; RusiaFil: Santos, Elizabeth del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Institute of Theoretical Chemistry; Alemania. Universitat Ulm; AlemaniaFil: Schmickler, Wolfgang. Universitat Ulm; Alemania. Institute of Theoretical Chemistry; AlemaniaFil: Nazmutdinov, Renat. Kazan National Research Technological University; Rusi
Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon
Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002
Population Connectivity and Phylogeography of a Coastal Fish, Atractoscion aequidens (Sciaenidae), across the Benguela Current Region: Evidence of an Ancient Vicariant Event
Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of contemporary and historical mechanisms shaping the evolutionary history of warm-temperate fish species. Using the genetic variation in the mitochondrial DNA Control Region and eight nuclear microsatellite DNA loci, we identified the presence of two highly divergent populations in a vagile and warm-temperate fish species, Atractoscion aequidens, across the Benguela region. The geographical distributions of the two populations, on either side of the perennial upwelling cell, suggest a strong correlation between the oceanographic features of the system and the breakdown of gene flow within this species. Genetic divergence (mtDNA φ (ST) = 0.902, microsatellite F (ST) = 0.055: probability of genetic homogeneity for either marker = p<0.001), absence of migrants (less than 1% per generation) between populations and coalescent estimates of time since most recent common ancestor suggest that the establishment of the main oceanographic features of the system (2 million years ago), particularly the strengthening and position of the perennial upwelling cell, is the most likely mechanism behind the observed isolation. Concordance between mitochondrial and nuclear genetic markers indicates that isolation and divergence of the northern and southern Benguela populations of A. aequidens occurred deep in the past and has continued to the present day. These findings suggest that the Benguela Current system may constitute an ancient and impermeable barrier to gene flow for warm-temperate fish species
An Overview of the Circular Economy among SMEs in the Basque Country: A Multiple Case Study.
Purpose: This research analyzes the maturity of environmental management as well as the degreeof to which the Circular Economy has been implemented in Basque SMEs.Design/methodology/approach:A total of 17 case studies were carried out in industrialSMEs companies in the Basque Country.Findings:The main results show that companies are limited to complying with the law and inmany cases are worried about the image of the company, although they are not committed toenvironmental issues. There is still a lot to do in SMEs, as they are the companies that face thebiggest challenges due to a lack of resources.Originality/value: Circular Economy aims to change a linear economy into promotingsustainability of the economy while also engaging in sustainable environmental protection. Thisresearch has focused on small and medium enterprises as they represent a 99% of companies inEurope and they are the ones that have the most difficulty reaching a stage of environmentalexcellence due to their limited resources
Predicting environmental concentrations and the potential risk of Plant Protection Products (PPP) on non-target soil organisms accounting for regional and landscape ecological variability in european soils
[EN] Plant Protection Products (PPP) raise concerns as their application may cause effects on some soil organisms considered non-target species which could be highly sensitive to some pesticides. The European Food and Safety Authority (EFSA), in collaboration with the Joint Research Centre (JRC) of the European Commission, has developed guidance and a software tool, Persistence in Soil Analytical Model (PERSAM), for conducting soil exposure assessments. EFSA PPR Panel has published recommendations for the risk assessment of non-target soil organisms. We have used PERSAM for calculating PPPs predicted environmental concentrations (PECs); and used the estimated PEC for assessing potential risks using Toxicity Exposure Ratios (TER) for selected soil organisms and good agricultural practices. Soil characteristics and environmental variables change along a latitudinal axis through the European continent, influencing the availability of PPP, their toxicity upon soil biota, and hence, impacting on the risk characterization. Although PERSAM includes as input geographical information, the in-formation is aggregated and not further detailed in the model outputs. Therefore, there is a need to develop landscape based environmental risk assessment methods addressing regional variability. The objective was to integrate spatially explicit exposure (PECs) and effect data (biological endpoints i.e. LC50, NOEC, etc.) to estimate the risk quotient (TER) of four PPP active substances (esfenvalerate, cyclaniliprole, picoxystrobin, fenamidone) on non-target species accounting European landscape and agricultural variability. The study was focused on the effects produced by the above-mentioned pesticides on two soil organisms: E. fetida earthworms and Folsomia sp. collembolans. After running PERSAM assuming a worst case application of PPPs, PECs in total soil and pore water were obtained for different depths in northern, central and southern European soils. With this data, soil variability and climatic differences among soils divided in three large Euroregions along a latitudinal transect (Northern, Central, Southern Europe) were analysed. Summarising, a trend to accumulate higher PECs and TERs in total soil was observed in the north decreasing towards the south. Higher PECs and TERs could be expected in pore water in southern soils, decreasing towards the north. The risk disparity between pollutant concentrations at different soils compartments should be taken into account for regulatory purposes, as well as the potential landscape variabilities among different Euroregions.This work has been partially funded by European Food Safety Authority (EFSA) through the grant NP/EFSA/AFSCO/2016/03. The authors Miguel Santos and Jose V Tarazona are employed with the EFSA in the Pesticides Peer Review and the Scientific Committee and Emerging Risks Units. However, the present article is published under the sole responsibility of the authors and may not be considered as an EFSA scientific output. The positions and opinions presented in this article are those of the authors alone and do not represent the views of EFSA
Molecular genetic, life-history and morphological variation in a coastal warm-temperature sciaenid fish:Evidence for an upwelling-driven speciation event
The marine environment is punctuated by biogeographical barriers that limit dispersal and gene flow in otherwise widespread species (Teske et al., 2011a,b; Briggs & Bowen, 2012; Luiz et al., 2012). These barriers may be physical obstacles such as landmasses (e.g. Isthmus of Panama) or less intuitive features such as deep water (Lessios et al., 2003), freshwater outflows (Floeter et al., 2008) or oceanographic features (Shaw et al., 2004; Galarza et al., 2009; von der Heyden et al., 2011). Upwelling cells and sea surface temperature (SSTs) gradients in particular are known to disrupt gene flow, leading to divergence of allopatric populations and species (Waters & Roy, 2004; Teske et al., 2011a; Henriques et al., 2012, 2014, 2015). However, as oceanographic features are seldom permanent and frequently subject to considerable environmental variability, many barriers often permit some level of permeability to dispersal (Floeter et al., 2008). Other processes may influence the persistence of differentiated allopatric taxa across such physical barriers (Bradbury et al., 2008), with ecological divergence (and diversifying selection) being reported as a major evolutionary process influencing the biogeographical distributions of marine species (Pelc et al., 2009; Teske et al., 2011a; Gaither et al., 2015)
Cartography of the urban land register, and its use in a GIS environment. Its application to the study of residential development in the south of Madrid
Ontogenetic and seasonal shifts in the diet of Diplodus cervinus hottentotus (Pisces: Sparidae) in southern Angola
Fishes of the family Sparidae occupy a diverse range of trophic niches, from herbivores to generalist omnivores and specialist predators (Hanel and Tsigenopoulos 2011). Feeding specialisation in this family is facilitated by diversity in tooth type and anterior jaw arrangement (Vandewalle et al. 1995). Other fish families, such as Cyprinidae and Labridae, have developed crushing pharyngeal teeth to process their food. Sparids, however, have retained a simple pharyngeal tooth arrangement and instead have developed molariform teeth to process hard-shelled molluscs and invertebrate prey. Hanel and Tsigenopoulos (2011) suggested that this alternate strategy is a major factor facilitating the trophic diversity in sparid fishes
Determining the daily spawning cycle of the chokka squid, Loligo reynaudii off the South African Coast
The study investigated the duration and peak of the daily spawning cycle of the chokka squid Loligo reynaudii, and the possibility of estimating the spawning frequency by means of classification and grouping (by age) of postovulatory follicles. Post-ovulatory follicles were classified into three types: new, intermediate or old, based in part on the degree of resorption of the follicles determined from histological sections. Ovulation in this species appears to be a rapid process, seen by the occurrence of both mature oocytes and post-ovulatory follicles in partially spent ovaries. Results suggest that chokka squid present a diel timing of spawning, with successive periods of egg accumulation at night, interrupted by periods of active spawning during the day. The ovarian cycle for this species appears typical of serial spawners. During the spawning phase ovaries go through ripe, partially spent and recovering stages by undergoing a process of maturation, ovulation and redeveloping, where a new batch of advanced oocytes is recruited. The cycle typically appears to last between 24 and 36 h, and may depend on a number of factors such as environmental conditions and the presence of predators. The short-lived (about 14 h) nature of the post-ovulatory follicles precludes the calculation of the exact spawning interval and does not allow us to accurately predict the spawning frequency. Together with the degree of oviduct fullness they do however give a good indication of imminent or recent spawning
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