404 research outputs found
Seguiment de mol·luscs opistobranquis a la platja des Caials (Cadaqués, Alt Empordà). Contribució al catàleg del Parc Natural de Cap de Creus
Es presenten els resultats de les observacions de mol•luscs opistobranquis realitzades a la platja des Caials (Cadaqués, Parc Natural de Cap de Creus). Els mostrejos es realitzaren durant el dia, entre els 0 i 28 metres de fondària, que comprenien comunitats d’algues fotòfiles de llocs encalmats, comunitats infralapidícoles, alguers de posidònia, comunitats d’algues esciàfiles de llocs encalmats o precoral•ligen, coral•ligen i fons detrítics, incloent les restes del vaixell enfonsat Llanishen, que constitueixen un substrat entre els 13 i 17 metres de fondària. El número d’espècies observades ha estat 48: Cephalaspidea (1), Anaspidea (2), Notaspidea (1), Umbraculoidea (2), Ascoglossa (4); Nudibranchia (38) desglossats en: Doridacea (18)
Arminacea (1),Dendronotacea (3) iAeolidacea (16). Es cita per primer cop a Catalunya
l’eolidaci Piseinotecus gabinierei.This paper presents the results of our observations of opisthobranch molluscs in platja (beach) des Caials (Cadaqués, Cap de Creus Natural Park, Girona, Spain). Samplings were conducted during the day, between 0 and 28 meters of water, including well lit algal communities, species that live beneath stones, Posidonia meadows, poorly lit algal environments, precoralligenous, coralligenous and detritic biocoenosis, and the remains of the Llanishen shipwreck, that conform a biotope between 13 and 17 meters
of depth. The total number of species positively identified was 48, distributed as follows: Cephalaspidea (1),Anaspidea (2), Notaspidea (1), Umbraculoidea (2), Ascoglossa (4); Nudibranchia (38) subdivided into Doridacea (18) Arminacea (1), Dendronotacea (3) i Aeolidacea (16). Among these, for the first time in the Catalonian coastal waters, we recorded the aeolidacean Piseinotecus gabinierei
The UlaG protein family defines novel structural and functional motifs grafted on an ancient RNase fold
Background: Bacterial populations are highly successful at colonizing new habitats and adapting to changing environmental conditions, partly due to their capacity to evolve novel virulence and metabolic pathways in response to stress conditions and to shuffle them by horizontal gene transfer (HGT). A common theme in the evolution of new functions consists of gene duplication followed by functional divergence. UlaG, a unique manganese-dependent metallo-b-lactamase (MBL) enzyme involved in L-ascorbate metabolism by commensal and symbiotic enterobacteria, provides a model for the study of the emergence of new catalytic activities from the modification of an ancient fold. Furthermore, UlaG is the founding member of the so-called UlaG-like (UlaGL) protein family, a recently established and poorly characterized family comprising divalent (and perhaps trivalent)metal-binding MBLs that catalyze transformations on phosphorylated sugars and nucleotides. Results: Here we combined protein structure-guided and sequence-only molecular phylogenetic analyses to dissect the molecular evolution of UlaG and to study its phylogenomic distribution, its relatedness with present-day UlaGL protein sequences and functional conservation. Phylogenetic analyses indicate that UlaGL sequences are present in Bacteria and Archaea, with bona fide orthologs found mainly in mammalian and plant-associated Gramnegative and Gram-positive bacteria. The incongruence between the UlaGL tree and known species trees indicates exchange by HGT and suggests that the UlaGL-encoding genes provided a growth advantage under changing conditions. Our search for more distantly related protein sequences aided by structural homology has uncovered that UlaGL sequences have a common evolutionary origin with present-day RNA processing and metabolizing MBL enzymes widespread in Bacteria, Archaea, and Eukarya. This observation suggests an ancient origin for the UlaGL family within the broader trunk of the MBL superfamily by duplication, neofunctionalization and fixation. Conclusions: Our results suggest that the forerunner of UlaG was present as an RNA metabolizing enzyme in the last common ancestor, and that the modern descendants of that ancestral gene have a wide phylogenetic distribution and functional roles. We propose that the UlaGL family evolved new metabolic roles among bacterial and possibly archeal phyla in the setting of a close association with metazoans, such as in the mammalian gastrointestinal tract or in animal and plant pathogens, as well as in environmental settings. Accordingly, the major evolutionary forces shaping the UlaGL family include vertical inheritance and lineage-specific duplication and acquisition of novel metabolic functions, followed by HGT and numerous lineage-specific gene loss events
A Metabolomics Signature Linked To Liver Fibrosis In The Serum Of Transplanted Hepatitis C Patients
Liver fibrosis must be evaluated in patients with hepatitis C virus (HCV) after liver transplantation because its severity affects their prognosis and the recurrence of HCV. Since invasive biopsy is still the gold standard to identify patients at risk of graft loss from rapid fibrosis progression, it becomes crucial the development of new accurate, non-invasive methods that allow repetitive examination of the patients. Therefore, we have developed a non-invasive, accurate model to distinguish those patients with different liver fibrosis stages. Two hundred and three patients with HCV were histologically classified (METAVIR) into five categories of fibrosis one year after liver transplantation. In this cross-sectional study, patients at fibrosis stages F0-F1 (n = 134) were categorised as "slow fibrosers" and F2-F4 (n = 69) as "rapid fibrosers". Chloroform/methanol serum extracts were analysed by reverse ultra-high performance liquid chromatography coupled to mass spectrometry. A diagnostic model was built through linear discriminant analyses. An algorithm consisting of two sphingomyelins and two phosphatidylcholines accurately classifies rapid and slow fibrosers after transplantation. The proposed model yielded an AUROC of 0.92, 71% sensitivity, 85% specificity, and 84% accuracy. Moreover, specific bile acids and sphingomyelins increased notably along with liver fibrosis severity, differentiating between rapid and slow fibrosers
Theoretical characterization of transition state dynamical resonances in heavy-light-heavy reactions
The resonant reactivity of three elementary Heavy-Light-Heavy reactions is presented and discussed. Collinear reactivity, in which a vibrational adiabatic model is constructed, is used for a detailed analysis of resonance phenomena, which appear as a direct consequence of transition state metastable states in the strong interaction region of the potential energy surface. Their influence on the detailed mechanism of the elementary process is also discussed. The shape of the resonant peak, and the phase and the Argand plot of the S-matrix are used for a further characterization.Three-dimensional approximate calculations are used to test the evolution of the energy dependent structure present in detailed quantities when sums and integrations over all partial waves contributing to reaction are taken into account to obtain the usual averaged global quantities such as integral state-to-state cross sections
Intrinsic alignment as an RSD contaminant in the DESI survey
We measure the tidal alignment of the major axes of luminous red galaxies (LRGs) from the Legacy Imaging Survey and use it to infer the artificial redshift-space distortion signature that will arise from an orientation-dependent, surface-brightness selection in the Dark Energy Spectroscopic Instrument (DESI) survey. Using photometric redshifts to downweight the shape–density correlations due to weak lensing, we measure the intrinsic tidal alignment of LRGs. Separately, we estimate the net polarization of LRG orientations from DESI’s fibre-magnitude target selection to be of order 10-2 along the line of sight. Using these measurements and a linear tidal model, we forecast a 0.5 per cent fractional decrease on the quadrupole of the two-point correlation function for projected separations of 40–80 h-1 Mpc. We also use a halo catalogue from the ABACUSSUMMIT cosmological simulation suite to reproduce this false quadrupole
The complex influence of ENSO on droughts in Ecuador
48 Pags.- 1 Tabl.- 18 Figs. The definitive version is available at: http://link.springer.com/journal/382In this study, we analyzed the influence of El Niño–Southern Oscillation (ENSO) on the spatio-temporal variability of droughts in Ecuador for a 48-year period (1965–2012). Droughts were quantified from 22 high-quality and homogenized time series of precipitation and air temperature by means of the Standardized Precipitation Evapotranspiration Index. In addition, the propagation of two different ENSO indices (El Niño 3.4 and El Niño 1 + 2 indices) and other atmospheric circulation processes (e.g., vertical velocity) on different time-scales of drought severity were investigated. The results showed a very complex influence of ENSO on drought behavior across Ecuador, with two regional patterns in the evolution of droughts: (1) the Andean chain with no changes in drought severity, and (2) the Western plains with less severe and frequent droughts. We also detected that drought variability in the Andes mountains is explained by the El Niño 3.4 index [sea surface temperature (SST) anomalies in the central Pacific], whereas the Western plains are much more driven by El Niño 1 + 2 index (SST anomalies in the eastern Pacific). Moreover, it was also observed that El Niño and La Niña phases enhance droughts in the Andes and Western plains regions, respectively. The results of this work could be crucial for predicting and monitoring drought variability and intensity in Ecuador.This work was supported by the EPhysLab (UVIGO-CSIC Associated Unit) and the research projects I-COOP H2O 2013CD0006: “Test multisectorial y actividades demostrativa sobre el potencial desarrollo de sistemas de monitorización de sequías en tiempo real en la región del oeste de Sudamérica” financed by the Spanish National Research Council, CGL2011-27574-CO2-02, CGL2014-52135-C03-01 and Red de variabilidad y cambio climático RECLIM (CGL2014-517221-REDT), financed by the Spanish Commission of Science and Technology and FEDER, and “LIFE12 ENV/ES/000536-Demonstration and validation of innovative methodology for regional climate change adaptation in the Mediterranean area (LIFE MEDACC)” financed by the LIFE programme of the European Commission. Cesar Azorin-Molina was supported by the JCI-2011-10263 Grant. Arturo Sanchez-Lorenzo was supported by the JCI-2012-12508 Grant. Miquel Tomas-Burguera was supported by a doctoral grant by the Ministry of Economy and Competitiveness and Natalia Martin-Hernandez was supported by a doctoral grant by the Aragón Regional Government. E. Aguilar was funded by the Grant CCI-009-ATN/OC-12439-RG-2012 from the Banco Iberoamericano de Desarrollo.Peer reviewe
The two-point correlation function covariance with fewer mocks
We present FITCOV an approach for accurate estimation of the covariance of two-point correlation functions that requires fewer mocks than the standard mock-based covariance. This can be achieved by dividing a set of mocks into jackknife regions and fitting the correction term first introduced in Mohammad & Percival (2022), such that the mean of the jackknife covariances corresponds to the one from the mocks. This extends the model beyond the shot-noise limited regime, allowing it to be used for denser samples of galaxies. We test the performance of our fitted jackknife approach, both in terms of accuracy and precision, using lognormal mocks with varying densities and approximate EZmocks mimicking the Dark Energy Spectroscopic Instrument LRG and ELG samples in the redshift range of z = [0.8, 1.1]. We find that the Mohammad–Percival correction produces a bias in the two-point correlation function covariance matrix that grows with number density and that our fitted jackknife approach does not. We also study the effect of the covariance on the uncertainty of cosmological parameters by performing a full-shape analysis. We demonstrate that our fitted jackknife approach based on 25 mocks can recover unbiased and as precise cosmological parameters as the ones obtained from a covariance matrix based on 1000 or 1500 mocks, while the Mohammad–Percival correction produces uncertainties that are twice as large. The number of mocks required to obtain an accurate estimation of the covariance for the two-point correlation function is therefore reduced by a factor of 40–60. The FITCOV code that accompanies this paper is available at this GitHub repository
Risk factors and outcomes of organ-space surgical site infections after elective colon and rectal surgery
Background: organ-space surgical site infections (SSI) are the most serious and costly infections after colorectal surgery. Most previous studies of risk factors for SSI have analysed colon and rectal procedures together. The aim of the study was to determine whether colon and rectal procedures have different risk factors and outcomes for organ-space SSI. Methods: a multicentre observational prospective cohort study of adults undergoing elective colon and rectal procedures at 10 Spanish hospitals from 2011 to 2014. Patients were followed up until 30 days post-surgery. Surgical site infection was defined according to the Centers for Disease Control and Prevention criteria. Oral antibiotic prophylaxis (OAP) was considered as the administration of oral antibiotics the day before surgery combined with systemic intravenous antibiotic prophylaxis. Results: of 3,701 patients, 2,518 (68%) underwent colon surgery and 1,183 (32%) rectal surgery. In colon surgery, the overall SSI rate was 16.4% and the organ-space SSI rate was 7.9%, while in rectal surgery the rates were 21.6% and 11.5% respectively (p < 0.001). Independent risk factors for organ-space SSI in colon surgery were male sex (Odds ratio -OR-: 1.57, 95% CI: 1.14-2.15) and ostomy creation (OR: 2.65, 95% CI: 1.8-3.92) while laparoscopy (OR: 0.5, 95% CI: 0.38-0.69) and OAP combined with intravenous antibiotic prophylaxis (OR: 0.7, 95% CI: 0.51-0.97) were protective factors. In rectal surgery, independent risk factors for organ-space SSI were male sex (OR: 2.11, 95% CI: 1.34-3.31) and longer surgery (OR: 1.49, 95% CI: 1.03-2.15), whereas OAP with intravenous antibiotic prophylaxis (OR: 0.49, 95% CI: 0.32-0.73) was a protective factor. Among patients with organ-space SSI, we found a significant difference in the overall 30-day mortality, being higher in colon surgery than in rectal surgery (11.5% vs 5.1%, p = 0.04). Conclusions: organ-space SSI in colon and rectal surgery has some differences in terms of incidence, risk factors and outcomes. These differences could be considered for surveillance purposes and for the implementation of preventive strategies. Administration of OAP would be an important measure to reduce the OS-SSI rate in both colon and rectal surgeries
Improving the detection of infectious diseases in at-risk migrants with an innovative integrated multi-infection screening digital decision support tool (IS-MiHealth) in primary care : a pilot cluster-randomized-controlled trial
There are major shortfalls in the identification and screening of at-risk migrant groups. This study aims to evaluate the effectiveness of a new digital tool (IS-MiHealth) integrated into the electronic patient record system of primary care centres in detecting prevalent migrant infections. IS-MiHealth provides targeted recommendations to health professionals for screening multiple infections, including human immunodeficiency virus (HIV), hepatitis B and C, active tuberculosis (TB), Chagas disease, strongyloidiasis and schistosomiasis, based on patient characteristics (including variables of country of origin, age and sex). A pragmatic pilot cluster-randomized-controlled trial was deployed from March to December 2018. Eight primary care centres in Catalonia, Spain, were randomly allocated 1:1 to use of the digital tool for screening, or to routine care. The primary outcome was the monthly diagnostic yield of all aggregated infections. Intervention and control sites were compared before and after implementation with respect to their monthly diagnostic yield using regression models. This study is registered on international standard randomised controlled trial number (ISRCTN) (ISRCTN14795012). A total of 15 780 migrants registered across the eight centres had at least one visit during the intervention period (March-December 2018), of which 14 598 (92.51%) fulfilled the criteria to be screened for at least one infection. There were 210 (2.57%) individuals from the intervention group with new diagnoses compared with 113 (1.49%) from the control group [odds ratio: 2.08, 95% confidence interval (CI) 1.63-2.64, P < 0.001]. The intervention centres raised their overall monthly diagnosis rate to 5.80 (95% CI 1.23-10.38, P = 0.013) extra diagnoses compared with the control centres. This monthly increase in diagnosis in intervention centres was also observed if we consider all cases together of HIV, hepatitis B and C, and active TB cases [2.72 (95% CI 0.43-5.00); P = 0.02] and was observed as well for the parasitic infections' group (Chagas disease, strongyloidiasis and schistosomiasis) 2.58 (95% CI 1.60-3.57; P < 0.001). The IS-MiHealth increased screening rate and diagnostic yield for key infections in migrants in a population-based primary care setting. Further testing and development of this new tool is warranted in larger trials and in other countries
A framework to measure the properties of intergalactic metal systems with two-point flux statistics
The abundance, temperature, and clustering of metals in the intergalactic
medium are important parameters for understanding their cosmic evolution and
quantifying their impact on cosmological analysis with the Ly forest.
The properties of these systems are typically measured from individual quasar
spectra redward of the quasar's Ly emission line, yet that approach
may provide biased results due to selection effects. We present an alternative
approach to measure these properties in an unbiased manner with the two-point
statistics commonly employed to quantify large-scale structure. Our model
treats the observed flux of a large sample of quasar spectra as a continuous
field and describes the one-dimensional, two-point statistics of this field
with three parameters per ion: the abundance (column density distribution),
temperature (Doppler parameter) and clustering (cloud-cloud correlation
function). We demonstrate this approach on multiple ions (e.g., C IV, Si IV, Mg
II) with early data from the Dark Energy Spectroscopic Instrument (DESI) and
high-resolution spectra from the literature. Our initial results show some
evidence that the C IV abundance is higher than previous measurements and
evidence for abundance evolution over time. The first full year of DESI
observations will have over an order of magnitude more quasar spectra than this
study. In a future paper we will use those data to measure the growth of
clustering and its impact on the Ly forest, as well as test other DESI
analysis infrastructure such as the pipeline noise estimates and the resolution
matrix.Comment: 15 pages, 14 figure
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