98 research outputs found
Modificaciones de la vegetación y del paisaje litoral del NW Ibérico en relación con los cambios climáticos ocurridos en la transición entre los estadios isotópicos 3 y 2. El depósito pleistoceno de Caamaño
XV lnternational A.P.L.E. Symposium of Palynolog
Transport through a quantum wire with a side quantum-dot array
A noninteracting quantum-dot array side-coupled to a quantum wire is studied.
Transport through the quantum wire is investigated by using a noninteracting
Anderson tunneling Hamiltonian. The conductance at zero temperature develops an
oscillating band with resonances and antiresonances due to constructive and
destructive interference in the ballistic channel, respectively. Moreover, we
have found an odd-even parity in the system, whose conductance vanishes for an
odd number of quantum dots while becomes for an even number. We
established an explicit relation between this odd-even parity, and the
positions of the resonances and antiresonances of the conductivity with the
spectrum of the isolated QD arrayComment: 5 pages, 4 figures, submitted to PR
Salud y medio ambiente
Erradicación microbasurales y difusión de cultura de entornoFloraciones algales nocivas (FAN): ¿Cómo se vigilan y controlan las intoxicaciones en Chile?Medioambiente y salud en el pregrado: desafío pendienteNiveles de dioxinas y furanos en leche matern
The role of Xpert MTB/RIF in diagnosing pulmonary tuberculosis in post-mortem tissues
The extent to which the Xpert MTB/RIF (Gene Xpert) contributes
to tuberculosis (TB) diagnosis in samples other than sputum and
cerebrospinal fluid remains uncertain. We aimed to assess the
role of Xpert MTB/RIF for detecting M. tuberculosis in
post-mortem tissues. We conducted a study among 30 complete
diagnostic autopsies (CDA) performed at the Maputo Central
Hospital (Mozambique). Lung tissues were screened for TB in all
cases. In addition other tissues were tested when compatible
lesions were identified in the histological exam. We used
in-house real time PCR and LAMP assays to confirm the presence
of M. tuberculosis DNA. The diagnosis of tuberculosis at death
was established based on microbiological and histopathological
results. Eight out of 30 cases (26.7%) were diagnosed of
tuberculosis. Xpert had a sensitivity to detect TB in lung
tissue of 87.5% (95% CI 47.3-99.7) and a specificity of 95.7%
(95% CI: 78.1-99.9). In-house DNA amplification methods and
Xpert showed 93.6% concordance for lung tissue and 100%
concordance for brain and liver tissues. The final cause of
death was attributable to tuberculosis in four cases. Xpert
MTB/RIF may represent a valuable, easy-to perform technique for
post-mortem TB diagnosis
Integrated metatranscriptomic and metagenomic analyses of stratified microbial assemblages in the open ocean
As part of an ongoing survey of microbial community gene expression in the ocean, we sequenced and compared ~38 Mbp of community transcriptomes and ~157 Mbp of community genomes from four bacterioplankton samples, along a defined depth profile at Station ALOHA in North Pacific subtropical gyre (NPSG). Taxonomic analysis suggested that the samples were dominated by three taxa: Prochlorales, Consistiales and Cenarchaeales, which comprised 36–69% and 29–63% of the annotated sequences in the four DNA and four cDNA libraries, respectively. The relative abundance of these taxonomic groups was sometimes very different in the DNA and cDNA libraries, suggesting differential relative transcriptional activities per cell. For example, the 125 m sample genomic library was dominated by Pelagibacter (~36% of sequence reads), which contributed fewer sequences to the community transcriptome (~11%). Functional characterization of highly expressed genes suggested taxon-specific contributions to specific biogeochemical processes. Examples included Roseobacter relatives involved in aerobic anoxygenic phototrophy at 75 m, and an unexpected contribution of low abundance Crenarchaea to ammonia oxidation at 125 m. Read recruitment using reference microbial genomes indicated depth-specific partitioning of coexisting microbial populations, highlighted by a transcriptionally active high-light-like Prochlorococcus population in the bottom of the photic zone. Additionally, nutrient-uptake genes dominated Pelagibacter transcripts, with apparent enrichment for certain transporter types (for example, the C4-dicarboxylate transport system) over others (for example, phosphate transporters). In total, the data support the utility of coupled DNA and cDNA analyses for describing taxonomic and functional attributes of microbial communities in their natural habitats.Gordon and Betty Moore FoundationUnited States. Dept. of EnergyNational Science Foundation (U.S.) (Science and Technology Center Award EF0424599
Fire and brief human occupations in Iberia during MIS 4: Evidence from Abric del Pastor (Alcoy, Spain)
There is a relatively low amount of Middle Paleolithic sites in Europe dating to MIS 4. Of the few that
exist, several of them lack evidence for anthropogenic fire, raising the question of how this period
of global cooling may have affected the Neanderthal population. The Iberian Peninsula is a key area
to explore this issue, as it has been considered as a glacial refugium during critical periods of the
Neanderthal timeline and might therefore yield archaeological contexts in which we can explore
possible changes in the behaviour and settlement patterns of Neanderthal groups during MIS 4.
Here we report recent data from Abric del Pastor, a small rock shelter in Alcoy (Alicante, Spain) with
a stratified deposit containing Middle Palaeolithic remains. We present absolute dates that frame
the sequence within MIS 4 and multi-proxy geoarchaeological evidence of in situ anthropogenic fire,
including microscopic evidence of in situ combustion residues and thermally altered sediment. We also
present archaeostratigraphic evidence of recurrent, functionally diverse, brief human occupation of the
rock shelter. Our results suggest that Neanderthals occupied the Central Mediterranean coast of the
Iberian Peninsula during MIS 4, that these Neanderthals were not undergoing climatic stress and they
were habitual fire users.This research was funded by a Leakey Foundation General Grant, Spanish Ministry of Science, Innovation
and Universities Projects HAR2008-06117/HIST and HAR2015-68321-P, Junta de Castilla y León-FEDER
Project BU235P18, the LabEx Sciences Archéologiques de Bordeaux (LaScArBx ANR-10-LABX-52) and ERC
Consolidator Grant ERC-CoG-2014. Archaeological excavations at Abric del Pastor are supported by the
Archaeological Museum of Alcoy and the Government of Valencia Cultural Heritage Department
Controlo químico de infestantes
Uma planta é considerada infestante quando nasce espontaneamente num local e momento indesejados, podendo interferir negativamente com a cultura instalada.
As infestantes competem com as culturas para o espaço, a luz, água e nutrientes, podendo atrasar e prejudicar as operações de colheita, depreciar o produto final e assegurarem a reinfestação nas culturas seguintes.
Dado o modo de propagação diferenciado das diversas espécies de infestantes, com as anuais a propagarem-se por semente e as perenes ou vivazes a assegurarem a sua propagação através de órgãos vegetativos (rizomas, bolbos, tubérculos, etc.), assim, também o seu controlo quer químico, quer mecânico terá que ser diferenciado, ou seja, para controlar infestantes anuais será suficiente destruir a sua parte aérea, enquanto para controlar infestantes perenes teremos que destruir os seus órgãos reprodutivos.
O controlo de infestantes poderá ser químico, através da utilização de herbicidas, ou mecânico pela utilização de alfaias agrícolas, tais como a charrua de aivecas, a charrua de discos, a grade de discos, o escarificador e a fresa. Quando a técnica utilizada na instalação das culturas é a sementeira directa, o controlo das infestantes terá que ser obrigatoriamente químico, enquanto se o recurso à mobilização do solo for a técnica mais utilizada (sistema de mobilização tradicional ou sistema de mobilização reduzida), o controlo das infestantes tanto poderá ser químico como mecânico.
Neste trabalho iremos abordar apenas, o controlo químico de infestantes
Genomic Characterization of Host Factors Related to SARS-CoV-2 Infection in People with Dementia and Control Populations: The GR@ACE/DEGESCO Study
Emerging studies have suggested several chromosomal regions as potential host genetic factors involved in the susceptibility to SARS-CoV-2 infection and disease outcome. We nested a COVID-19 genome-wide association study using the GR@ACE/DEGESCO study, searching for susceptibility factors associated with COVID-19 disease. To this end, we compared 221 COVID-19 confirmed cases with 17,035 individuals in whom the COVID-19 disease status was unknown. Then, we performed a meta-analysis with the publicly available data from the COVID-19 Host Genetics Initiative. Because the APOE locus has been suggested as a potential modifier of COVID-19 disease, we added sensitivity analyses stratifying by dementia status or by disease severity. We confirmed the existence of the 3p21.31 region (LZTFL1, SLC6A20) implicated in the susceptibility to SARS-CoV-2 infection and TYK2 gene might be involved in COVID-19 severity. Nevertheless, no statistically significant association was observed in the COVID-19 fatal outcome or in the stratified analyses (dementia-only and non-dementia strata) for the APOE locus not supporting its involvement in SARS-CoV-2 pathobiology or COVID-19 prognosis
Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks : The GR@ACE project
Introduction: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. Methods: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. Results: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. Discussion: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series
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