329 research outputs found
Preliminary experience with the smooth muscle troponin-like protein, calponin, as a novel biomarker for diagnosing acute aortic dissection
Aims The early diagnosis of acute aortic dissection (AD) remains challenging. We sought to determine the utility of the troponin-like protein of smooth muscle, calponin, as a diagnostic biomarker of acute AD. Methods and results Immunoassays against calponin (acidic, basic, and neutral isoforms) were developed and the levels were compared in a convenience sample of 59 patients with radiographically proven AD [34 males, age 59+15 (SD) years] vs. 158 patients suspected of having AD at presentation (116 males, age 63+15 years) but whose final diagnosis was not AD. Basic calponin, which is the most specific and abundant in smooth muscle, and acidic calponin, respectively, showed greater than two-fold and three-fold elevations in patients with acute AD. Diagnostic performance as determined by receiver-operating characteristics curve analysis showed that both acidic and basic calponin have the potential to detect AD in the first 24 h [respective areas under the curve (AUCs) 0.63 and 0.58], with superior performance of basic calponin (when compared with acidic) in the initial 6 h (respective AUCs 0.63 and 0.67). Conclusion Circulating calponin levels were elevated in acute AD compared with controls. These biomarkers have the potential for use as an early diagnostic biomarker for acute AD. Keywords Aortic dissection ? Biomarke
Molecular characterization of the diet of the planktonic community in Málaga Bay (NW Alboran Sea)
The seasonal changes in structure and functioning of the pelagic trophic web in Málaga Bay (NW Alboran Sea) are related to the annual hydrological cycle. However, time series analyses have shown that the relationship between interannual hydrological variability and the plankton community composition is weak. This might be due to different human-induced pressures (nutrient pollution, coastal fisheries) acting on different compartments of the trophic web. The net effect of all these factors would depend on how the ecosystem channels changes in the composition and abundance of each trophic level. Interactions of phytoplankton-ciliates-zooplankton might have a central role in the regulation of the trophic web in Málaga Bay, although the trophic relations of the dominant groups remain still undefined. In order to identify the dominant trophic relationships we aimed to characterise the diet of key ichthyo- and mesozooplankton species in the field. Given that gut content preys (phyto- and microplankton) are fragile and not easy to identify visually, we developed species-specific molecular markers to detect their presence/absence within the predators gut
Genomic transformation and social organization during the Copper Age–Bronze Age transition in southern Iberia
The emerging Bronze Age (BA) of southeastern Iberia saw marked social changes. Late Copper Age (CA) settlements were abandoned in favor of hilltop sites, and collective graves were largely replaced by single or double burials with often distinctive grave goods indirectly reflecting a hierarchical social organization, as exemplified by the BA El Argar group. We explored this transition from a genomic viewpoint by tripling the amount of data available for this period. Concomitant with the rise of El Argar starting ~2200 cal BCE, we observe a complete turnover of Y-chromosome lineages along with the arrival of steppe-related ancestry. This pattern is consistent with a founder effect in male lineages, supported by our finding that males shared more relatives at sites than females. However, simple two-source models do not find support in some El Argar groups, suggesting additional genetic contributions from the Mediterranean that could predate the BA.Introduction Results - Genetic substructure in the Iberian CA - Genetic turnover in the southern Iberian BA and the rise of El Argar - Mediterranean and central European ancestries shaped the genetic profile of southeastern BA groups in Iberia - A late Argar genetic outlier makes links to North Africa and the central Mediterranean - Insights into phenotypic variation, demography, and social correlates of CA and EBA El Argar societies Discussion Material and method
Strategic approaches to restoring ecosystems can triple conservation gains and halve costs.
International commitments for ecosystem restoration add up to one-quarter of the world's arable land. Fulfilling them would ease global challenges such as climate change and biodiversity decline but could displace food production and impose financial costs on farmers. Here, we present a restoration prioritization approach capable of revealing these synergies and trade-offs, incorporating ecological and economic efficiencies of scale and modelling specific policy options. Using an actual large-scale restoration target of the Atlantic Forest hotspot, we show that our approach can deliver an eightfold increase in cost-effectiveness for biodiversity conservation compared with a baseline of non-systematic restoration. A compromise solution avoids 26% of the biome's current extinction debt of 2,864 plant and animal species (an increase of 257% compared with the baseline). Moreover, this solution sequesters 1 billion tonnes of CO2-equivalent (a 105% increase) while reducing costs by US$28 billion (a 57% decrease). Seizing similar opportunities elsewhere would offer substantial contributions to some of the greatest challenges for humankind
Identification of Yeast Transcriptional Regulation Networks Using Multivariate Random Forests
The recent availability of whole-genome scale data sets that investigate complementary and diverse aspects of transcriptional regulation has spawned an increased need for new and effective computational approaches to analyze and integrate these large scale assays. Here, we propose a novel algorithm, based on random forest methodology, to relate gene expression (as derived from expression microarrays) to sequence features residing in gene promoters (as derived from DNA motif data) and transcription factor binding to gene promoters (as derived from tiling microarrays). We extend the random forest approach to model a multivariate response as represented, for example, by time-course gene expression measures. An analysis of the multivariate random forest output reveals complex regulatory networks, which consist of cohesive, condition-dependent regulatory cliques. Each regulatory clique features homogeneous gene expression profiles and common motifs or synergistic motif groups. We apply our method to several yeast physiological processes: cell cycle, sporulation, and various stress conditions. Our technique displays excellent performance with regard to identifying known regulatory motifs, including high order interactions. In addition, we present evidence of the existence of an alternative MCB-binding pathway, which we confirm using data from two independent cell cycle studies and two other physioloigical processes. Finally, we have uncovered elaborate transcription regulation refinement mechanisms involving PAC and mRRPE motifs that govern essential rRNA processing. These include intriguing instances of differing motif dosages and differing combinatorial motif control that promote regulatory specificity in rRNA metabolism under differing physiological processes
Hydroxychloroquine is associated with a lower risk of polyautoimmunity: data from the RELESSER Registry
OBJECTIVES: This article estimates the frequency of polyautoimmunity and associated factors in a large retrospective cohort of patients with SLE. METHODS: RELESSER (Spanish Society of Rheumatology Lupus Registry) is a nationwide multicentre, hospital-based registry of SLE patients. This is a cross-sectional study. The main variable was polyautoimmunity, which was defined as the co-occurrence of SLE and another autoimmune disease, such as autoimmune thyroiditis, RA, scleroderma, inflammatory myopathy and MCTD. We also recorded the presence of multiple autoimmune syndrome, secondary SS, secondary APS and a family history of autoimmune disease. Multiple logistic regression analysis was performed to investigate possible risk factors for polyautoimmunity. RESULTS: Of the 3679 patients who fulfilled the criteria for SLE, 502 (13.6%) had polyautoimmunity. The most frequent types were autoimmune thyroiditis (7.9%), other systemic autoimmune diseases (6.2%), secondary SS (14.1%) and secondary APS (13.7%). Multiple autoimmune syndrome accounted for 10.2% of all cases of polyautoimmunity. A family history was recorded in 11.8%. According to the multivariate analysis, the factors associated with polyautoimmunity were female sex [odds ratio (95% CI), 1.72 (1.07, 2.72)], RP [1.63 (1.29, 2.05)], interstitial lung disease [3.35 (1.84, 6.01)], Jaccoud arthropathy [1.92 (1.40, 2.63)], anti-Ro/SSA and/or anti-La/SSB autoantibodies [2.03 (1.55, 2.67)], anti-RNP antibodies [1.48 (1.16, 1.90)], MTX [1.67 (1.26, 2.18)] and antimalarial drugs [0.50 (0.38, 0.67)]. CONCLUSION: Patients with SLE frequently present polyautoimmunity. We observed clinical and analytical characteristics associated with polyautoimmunity. Our finding that antimalarial drugs protected against polyautoimmunity should be verified in future studies
Genomic transformation and social organization during the Copper Age-Bronze Age transition in southern Iberia
The emerging Bronze Age (BA) of southeastern Iberia saw marked social changes. Late Copper Age (CA) settlements were abandoned in favor of hilltop sites, and collective graves were largely replaced by single or double burials with often distinctive grave goods indirectly reflecting a hierarchical social organization, as exemplified by the BA El Argar group. We explored this transition from a genomic viewpoint by tripling the amount of data available for this period. Concomitant with the rise of El Argar starting ~2200 cal BCE, we observe a complete turnover of Y-chromosome lineages along with the arrival of steppe-related ancestry. This pattern is consistent with a founder effect in male lineages, supported by our finding that males shared more relatives at sites than females. However, simple two-source models do not find support in some El Argar groups, suggesting additional genetic contributions from the Mediterranean that could predate the BA
A feature selection method for classification within functional genomics experiments based on the proportional overlapping score
Background: Microarray technology, as well as other functional genomics experiments, allow simultaneous measurements of thousands of genes within each sample. Both the prediction accuracy and interpretability of a classifier could be enhanced by performing the classification based only on selected discriminative genes. We propose a statistical method for selecting genes based on overlapping analysis of expression data across classes. This method results in a novel measure, called proportional overlapping score (POS), of a feature's relevance to a classification task.Results: We apply POS, along-with four widely used gene selection methods, to several benchmark gene expression datasets. The experimental results of classification error rates computed using the Random Forest, k Nearest Neighbor and Support Vector Machine classifiers show that POS achieves a better performance.Conclusions: A novel gene selection method, POS, is proposed. POS analyzes the expressions overlap across classes taking into account the proportions of overlapping samples. It robustly defines a mask for each gene that allows it to minimize the effect of expression outliers. The constructed masks along-with a novel gene score are exploited to produce the selected subset of genes
Growth Strategies of Tropical Tree Species: Disentangling Light and Size Effects
An understanding of the drivers of tree growth at the species level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in species-rich tropical forests, it is largely unknown how species differ in their response of growth to resource availability and individual size. We use a hierarchical Bayesian approach to quantify the impact of light availability and tree diameter on growth of 274 woody species in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual tree was estimated from yearly vertical censuses of canopy density. The hierarchical Bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare species correctly weighted by their abundance. All species grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all species exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light) varied over a 9-fold range and reflect strong growth-strategy differentiation between the species. As a consequence, growth rankings of the species at low (2%) and high light (20%) were highly correlated. Rare species tended to grow faster and showed a greater sensitivity to light than abundant species. Overall, tree size was less important for growth than light and about half the species were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and tree diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping tree growth in the tropics
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