29 research outputs found

    Body size and mobility explain species centralities in the Gulf of California food web

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    Anthropic activities impact ecosystems worldwide thus contributing to the rapid erosion of biodiversity. The failure of traditional strategies targeting single species highlighted ecosystems as the most suitable scale to plan biodiversity management. Network analysis represents an ideal tool to model interactions in ecosystems and centrality indices have been extensively applied to quantify the structural and functional importance of species in food webs. However, many network studies fail in deciphering the ecological mechanisms that lead some species to occupy the most central positions in food webs. To address this question, we built a high-resolution food web of the Gulf of California and quantified species position using 15 centrality indices and the trophic level. We then modelled the values of each index as a function of traits and other attributes (e.g., habitat). We found that body size and mobility are the best predictors of indices that characterize species importance at local, meso- and global scale, especially in presence of data accounting for energy direction. This result extends previous findings that illustrated how a restricted set of traitaxes can predict whether two species interact in food webs. In particular, we show that traits can also help understanding the way species are affected by and mediate indirect effects. The traits allow focusing on the processes that shape the food web, rather than providing case-specific indications as the taxonomy-based approach. We suggest that future network studies should consider the traits to explicitly identify the causal relationships that link anthropic impacts to role changes of species in food webs

    Role of age and comorbidities in mortality of patients with infective endocarditis

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    Purpose: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. Methods: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015. Patients were stratified into three age groups:<65 years, 65 to 80 years, and = 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. Results: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 = 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients =80 years who underwent surgery were significantly lower compared with other age groups (14.3%, 65 years; 20.5%, 65-79 years; 31.3%, =80 years). In-hospital mortality was lower in the <65-year group (20.3%, <65 years;30.1%, 65-79 years;34.7%, =80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%, =80 years; p = 0.003).Independent predictors of mortality were age = 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI = 3 (HR:1.62; 95% CI:1.39–1.88), and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared, the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. Conclusion: There were no differences in the clinical presentation of IE between the groups. Age = 80 years, high comorbidity (measured by CCI), and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

    Differential clinical characteristics and prognosis of intraventricular conduction defects in patients with chronic heart failure

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    Intraventricular conduction defects (IVCDs) can impair prognosis of heart failure (HF), but their specific impact is not well established. This study aimed to analyse the clinical profile and outcomes of HF patients with LBBB, right bundle branch block (RBBB), left anterior fascicular block (LAFB), and no IVCDs. Clinical variables and outcomes after a median follow-up of 21 months were analysed in 1762 patients with chronic HF and LBBB (n = 532), RBBB (n = 134), LAFB (n = 154), and no IVCDs (n = 942). LBBB was associated with more marked LV dilation, depressed LVEF, and mitral valve regurgitation. Patients with RBBB presented overt signs of congestive HF and depressed right ventricular motion. The LAFB group presented intermediate clinical characteristics, and patients with no IVCDs were more often women with less enlarged left ventricles and less depressed LVEF. Death occurred in 332 patients (interannual mortality = 10.8%): cardiovascular in 257, extravascular in 61, and of unknown origin in 14 patients. Cardiac death occurred in 230 (pump failure in 171 and sudden death in 59). An adjusted Cox model showed higher risk of cardiac death and pump failure death in the LBBB and RBBB than in the LAFB and the no IVCD groups. LBBB and RBBB are associated with different clinical profiles and both are independent predictors of increased risk of cardiac death in patients with HF. A more favourable prognosis was observed in patients with LAFB and in those free of IVCDs. Further research in HF patients with RBBB is warranted

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Ictiofauna asociada al manglar del estero el Conchalito,ensenada de La Paz, Baja California Sur, México

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    Se presenta la lista sistemática de los peces recolectados en el manglar del estero El Conchalito, durante junio de 1996 a mayo de 1998. La lista consiste de 1 clase, 11 órdenes, 22 familias, 39 géneros y 55 especies. Las familias mejor representadas en número de especies fueron Haemulidae (11), Gerreidae (7) y Gobiidae (5); once estuvieron representadas por sólo una. Veinticinco (45%) tienen importancia económica, habitan en el ecosistema de manglar del estero durante las primeras etapas de su vida y cuando adultas son capturadas por las pesquerías artesanales de la Bahía de La Paz. Asimismo, otras 18 especies son potencialmente importantes para esas actividades. Se establece la novedad del registro nominal de 5 especies para la Bahía: Centropomus armatus, Epinephelus niphobles, Haemulopsis nitidus, Myrichthys tigrinus y Pomadasys bayanus. Finalmente se discute la importancia del estero, como hábitat primario de crianza, alimentación y reclutamiento para la ictiofauna de los ecosistemas acuáticos adyacentes

    Length–weight relations for 14 fish species of La Paz Bay, Baja California Sur, México

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    The presently reported study provides length–weight relations of 14 fish species from mangrove swamps of La Paz Bay, Baja California Sur, México: Diapterus brevirostris (Sauvage, 1879); Eucinostomus currani Zahuranec, 1980; Eucinostomus dowii (Gill, 1863); Eucinostomus entomelas Zahuranec, 1980; Eucinostomus gracilis (Gill, 1862); Ctenogobius sagittula (Günther, 1862); Haemulopsis nitidus (Steindachner, 1869); Pomadasys bayanus Jordan et Evermann, 1898; Hyporhamphus naos Banford et Collette, 2001; Lutjanus argentiventris (Peters, 1869); Lutjanus novemfasciatus Gill, 1862; Mugil curema Valenciennes, 1836; Paralabrax maculatofasciatus (Steindachner, 1868); Sphoeroides annulatus (Jenyns, 1842). Fish were caught at 8 locations within July 2010–September 2011. Specimens were collected monthly using beach seines (mesh size 2.0 cm), measured with a digital calliper, and weighed with a digital balance to determine the standard length and weight, respectively. Values of b ranged from 2.21 to 3.45

    Identification of gerreid species (Actinopterygii: Perciformes: Gerreidae) from the Pacific coast of Mexico based on sagittal otolith morphology analysis

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    Background. Although the species of the family Gerreidae have been subjected to many studies, their taxonomy at specific- and sometimes generic levels is still confusing. To contribute to the clarification of the taxonomy of the Mexican Pacific mojarras, the morphology of sagittal otoliths among six species of mojarras (Diapterus brevirostris, Eugerres lineatus, Eucinostomus dowii, E entomelas, E. currani, and Gerres cinereus) was compared using size and shape descriptors. Otolith shape has long been known to be species-specific but this has not been tested in species of the family Gerreidae. Therefore, our goal was to explore the effectiveness of otolith descriptors for identifying gerreid fish at species level. Materials and methods. Gerreid fish were captured between January 2009 and January 2010, off the Pacific coast of Mexico. The right- and left sagittae of 160 individuals were extracted for analysis. Size and shape descriptors considered in the presently reported analysis were: surface area, perimeter, length, width, rectangularity, ellipticity, roundness, circularity, aspect ratio, form-factor, Feret length, Feret width, Feret maximum, Feret minimum, diameter maximum, diameter minimum, diameter mean, ratio maximum, and ratio minimum. Other measurements were made in the otolith region of sulcus acusticus, such as: cauda length, ostium length, ostium width, sulcus length, and rostrum width. Canonical discriminant analysis on otoliths morphology was used to identify differences between species. Results. Rectangularity, roundness, otolith length, and Feret length were the main otolith descriptors that explain the inter-specific variability. Significant differences (Wilks’ lambdas (λ), P 90%) allowed the separation of the species by using discriminant functions. Results from both G-test and Cohen’s kappa procedure confirmed the high rates of classification success obtained by the discriminant analysis. Conclusion. These results suggest the usefulness of otolith morphology for differentiation of Gerreidae species from Mexican Pacific waters, thereby demonstrating that otolith shape is species-specific. Otolith morphology descriptions provided in this study is presented for the first time for the species included

    Identification of gerreid species (Actinopterygii: Perciformes: Gerreidae) from the Pacific coast of Mexico based on sagittal otolith morphology analysis

    No full text
    Background. Although the species of the family Gerreidae have been subjected to many studies, their taxonomy at specific- and sometimes generic levels is still confusing. To contribute to the clarification of the taxonomy of the Mexican Pacific mojarras, the morphology of sagittal otoliths among six species of mojarras (Diapterus brevirostris, Eugerres lineatus, Eucinostomus dowii, E entomelas, E. currani, and Gerres cinereus) was compared using size and shape descriptors. Otolith shape has long been known to be species-specific but this has not been tested in species of the family Gerreidae. Therefore, our goal was to explore the effectiveness of otolith descriptors for identifying gerreid fish at species level. Materials and methods. Gerreid fish were captured between January 2009 and January 2010, off the Pacific coast of Mexico. The right- and left sagittae of 160 individuals were extracted for analysis. Size and shape descriptors considered in the presently reported analysis were: surface area, perimeter, length, width, rectangularity, ellipticity, roundness, circularity, aspect ratio, form-factor, Feret length, Feret width, Feret maximum, Feret minimum, diameter maximum, diameter minimum, diameter mean, ratio maximum, and ratio minimum. Other measurements were made in the otolith region of sulcus acusticus, such as: cauda length, ostium length, ostium width, sulcus length, and rostrum width. Canonical discriminant analysis on otoliths morphology was used to identify differences between species. Results. Rectangularity, roundness, otolith length, and Feret length were the main otolith descriptors that explain the inter-specific variability. Significant differences (Wilks’ lambdas (λ), P 90%) allowed the separation of the species by using discriminant functions. Results from both G-test and Cohen’s kappa procedure confirmed the high rates of classification success obtained by the discriminant analysis. Conclusion. These results suggest the usefulness of otolith morphology for differentiation of Gerreidae species from Mexican Pacific waters, thereby demonstrating that otolith shape is species-specific. Otolith morphology descriptions provided in this study is presented for the first time for the species included
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