Showing papers by "University of Córdoba (Spain) published in 2015"

Increasing aridity reduces soil microbial diversity and abundance in global drylands

Abstract: Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands.

Expert consensus document: European Consensus Statement on congenital hypogonadotropic hypogonadism—pathogenesis, diagnosis and treatment

Abstract: Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder caused by the deficient production, secretion or action of gonadotropin-releasing hormone (GnRH), which is the master hormone regulating the reproductive axis. CHH is clinically and genetically heterogeneous, with >25 different causal genes identified to date. Clinically, the disorder is characterized by an absence of puberty and infertility. The association of CHH with a defective sense of smell (anosmia or hyposmia), which is found in ∼50% of patients with CHH is termed Kallmann syndrome and results from incomplete embryonic migration of GnRH-synthesizing neurons. CHH can be challenging to diagnose, particularly when attempting to differentiate it from constitutional delay of puberty. A timely diagnosis and treatment to induce puberty can be beneficial for sexual, bone and metabolic health, and might help minimize some of the psychological effects of CHH. In most cases, fertility can be induced using specialized treatment regimens and several predictors of outcome have been identified. Patients typically require lifelong treatment, yet ∼10-20% of patients exhibit a spontaneous recovery of reproductive function. This Consensus Statement summarizes approaches for the diagnosis and treatment of CHH and discusses important unanswered questions in the field.

Data quality aware analysis of differential expression in RNA-seq with NOISeq R/Bioc package

Abstract: European Union Seventh Framework Programme [FP7/2007-2013, 306000]; Spanish Ministry of Science and Innovation [MICINN, BIO2008-04638-E], in the framework of ERA-Net Pathogenomics; MICINN [DPI2008-06880-C03-03/DPI]. Funding for open access charge: University of Florida, Publication Funds.

A Tutorial on Multilabel Learning

Abstract: Multilabel learning has become a relevant learning paradigm in the past years due to the increasing number of fields where it can be applied and also to the emerging number of techniques that are being developed. This article presents an up-to-date tutorial about multilabel learning that introduces the paradigm and describes the main contributions developed. Evaluation measures, fields of application, trending topics, and resources are also presented.

Understanding nitrate assimilation and its regulation in microalgae.

Abstract: Nitrate assimilation is a key process for nitrogen (N) acquisition in green microalgae. Among Chlorophyte algae, Chlamydomonas reinhardtii has resulted to be a good model system to unravel important facts of this process, and has provided important insights for agriculturally relevant plants. In this work, the recent findings on nitrate transport, nitrate reduction and the regulation of nitrate assimilation are presented in this and several other algae. Latest data have shown nitric oxide (NO) as an important signal molecule in the transcriptional and posttranslational regulation of nitrate reductase and inorganic N transport. Participation of regulatory genes and proteins in positive and negative signaling of the pathway and the mechanisms involved in the regulation of nitrate assimilation, as well as those involved in Molybdenum cofactor synthesis required to nitrate assimilation, are critically reviewed.

Monounsaturated Fatty Acid–Enriched High-Fat Diets Impede Adipose NLRP3 Inflammasome–Mediated IL-1β Secretion and Insulin Resistance Despite Obesity

Abstract: Saturated fatty acid (SFA) high-fat diets (HFDs) enhance interleukin (IL)-1β-mediated adipose inflammation and insulin resistance. However, the mechanisms by which different fatty acids regulate IL-1β and the subsequent effects on adipose tissue biology and insulin sensitivity in vivo remain elusive. We hypothesized that the replacement of SFA for monounsaturated fatty acid (MUFA) in HFDs would reduce pro-IL-1β priming in adipose tissue and attenuate insulin resistance via MUFA-driven AMPK activation. MUFA-HFD-fed mice displayed improved insulin sensitivity coincident with reduced pro-IL-1β priming, attenuated adipose IL-1β secretion, and sustained adipose AMPK activation compared with SFA-HFD-fed mice. Furthermore, MUFA-HFD-fed mice displayed hyperplastic adipose tissue, with enhanced adipogenic potential of the stromal vascular fraction and improved insulin sensitivity. In vitro, we demonstrated that the MUFA oleic acid can impede ATP-induced IL-1β secretion from lipopolysaccharide- and SFA-primed cells in an AMPK-dependent manner. Conversely, in a regression study, switching from SFA- to MUFA-HFD failed to reverse insulin resistance but improved fasting plasma insulin levels. In humans, high-SFA consumers, but not high-MUFA consumers, displayed reduced insulin sensitivity with elevated pycard-1 and caspase-1 expression in adipose tissue. These novel findings suggest that dietary MUFA can attenuate IL-1β-mediated insulin resistance and adipose dysfunction despite obesity via the preservation of AMPK activity.

Biomass-Derived Porous Carbon Materials: Synthesis and Catalytic Applications

Abstract: Novel biomass-derived porous carbons are attractive candidates for the preparation of carbon-supported catalysts with a wide range of catalytic applications. Such carbonaceous catalysts are environmentally benign and could provide a cost-competitive advantage as compared to existing heterogeneous catalysts. Tunable surface properties of carbon materials and excellent physical properties (e.g., hydrophobicity, chemically inert nature, etc.) are compatible with diverse catalysis reactions including organic transformations, as well as electro- and photochemical processes in aqueous solutions. This contribution provides an overview on the utilization of different biomass feedstocks and/or biomass-derived precursors for the synthesis of carbonaceous materials to design advanced catalytic systems and their emerging applications in catalysis.

Prenatal exposure to bisphenol A and phthalates and childhood respiratory tract infections and allergy

Abstract: Background There is growing concern that prenatal exposure to bisphenol A (BPA) and phthalates, which are widely used in consumer products, might affect susceptibility to infections and the development of allergy and asthma in children, but there are currently very few prospective studies. Objective We sought to evaluate whether prenatal exposure to BPA and phthalates increases the risk of respiratory and allergic outcomes in children at various ages from birth to 7 years. Methods We measured BPA and metabolites of high-molecular-weight phthalates, 4 di-(2-ethylhexyl) phthalate (DEHP) metabolites (Σ 4 DEHP) and mono-benzyl phthalate (MBzP), and 3 low-molecular-weight phthalate (LMWP) metabolites (Σ 3 LMWP) in urine samples collected during the first and third trimesters in pregnant women participating in the Infancia y Medio Ambiente–Sabadell birth cohort study. The occurrence of chest infections, bronchitis, wheeze, and eczema in children was assessed at ages 6 and 14 months and 4 and 7 years through questionnaires given to the mothers. Atopy (specific IgE measurement) and asthma (questionnaire) were assessed at ages 4 and 7 years, respectively. Results The relative risks (RRs) of wheeze (RR, 1.20; 95% CI, 1.03-1.40; P = .02), chest infections (RR, 1.15; 95% CI, 1.00-1.32; P = .05), and bronchitis (RR, 1.18; 95% CI, 1.01-1.37; P = .04) at any age increased for each doubling in concentration of maternal urinary BPA. Σ 4 DEHP metabolites were associated with the same outcomes (wheeze: RR, 1.25; 95% CI, 1.04-1.50, P = .02; chest infections: RR, 1.15; 95% CI, 0.97-1.35; P = .11; bronchitis: RR, 1.20; 95% CI, 1.01-1.43; P = .04). MBzP was associated with higher risk of wheeze (RR, 1.15; 95% CI, 1.00-1.33; P = .05). The risk of asthma at age 7 years was also increased with increasing prenatal BPA, Σ 4 DEHP, and MBzP exposure. There were no other exposure-outcome associations. Conclusions Prenatal exposure to BPA and high-molecular-weight phthalates might increase the risk of asthma symptoms and respiratory tract infections throughout childhood.

Graphene quantum dots in analytical science

Abstract: Graphene quantum dots (GQDs) are small fluorescent nanoparticles with unique properties that make them attractive tools for research in various fields. We review their state of the art in analytical chemistry and summarize their analytical applications. Also, we deal with GQDs as target analytes, a scarcely explored aspect in analytical nanoscience and nanotechnology, and suggest potential future directions for GQD-based analytical research.

Olive domestication and diversification in the Mediterranean Basin

Abstract: Summary Olive (Olea europaea ssp. europaea) is the most important oil fruit crop in temperate areas, but the origin of the cultivated olive remains unclear. The existence of one or several domestication events in the Mediterranean Basin (MB) is still debated. We analyzed a dataset of 387 cultivated and wild accessions that were genotyped at 25 simple-sequence repeat (SSR) loci. The sample represented genetic diversity at the geographic extremes of the MB. We inferred relationships among samples and also applied approximate Bayesian computation to estimate the most probable demographic model of our samples. Cultivated olives clustered into three different gene pools (Q1, Q2 and Q3), corresponding loosely to the west, central and eastern MB, respectively. Q1 consisted primarily of accessions from southern Spain, retained the fingerprint of a genetic bottleneck, and was closely related to accessions from the eastern MB. Q2 showed signs of recent admixture with wild olives and may derive from a local domestication event in the central MB. Overall our results suggest that admixture shaped olive germplasm and perhaps also local domestication events.

Literature review on rebound effect of water saving measures and analysis of a Spanish case study

Abstract: The hypothesis of a rebound effect as a consequence of water saving investments is taken analogically from the Jevons paradox models in energy economics. The European Commission (EC) alert about the consequences in water stressed regions that are investing heavily in modernization of irrigation networks and systems. This paper reviews the literature, linking water savings with water diversion and water depletion, both from theoretical models and empirical evidence from the published research. In order to increase knowledge of this phenomenon, a new empirical case study is presented based on a survey of 36,000 ha of recently modernized irrigated areas in the Guadalquivir basin (southern Spain). The results of the case study illustrates the conditions that may avoid rebound effect, although the results of the available empirical evidence and the published theoretical research are diverse and lead to contradictory results. Further research is therefore needed to determine the causes and solutions of water saving investment impacts and the possible speculative rebound effect.

Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands

Abstract: Summary � We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity (FD) and community-weighted mean trait values (CWM)), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e. the provision of several ecosystem functions simultaneously). � Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or nonsprouting shrub species considered. � FD and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g. vegetative height or lateral spread) and leaf traits (e.g. specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r 2 = 0.63). FD also

Diffuse Reflectance Spectroscopy

Abstract: The appearance of a soil results from the interaction of its different constituents with incident light. Color and various other attributes of the appearance of soil are highly sensitive to the nature, proportion, particle size and morphology, and spatial association of its mineral and organic components. In fact, color has been used for more than 75 yr to obtain information about these soil properties with a goal of characterizing and distinguishing soil types. The demand for a standardized method to describe soil color was met by the adoption of the Munsell notation by the USA Soil Survey Program in 1949 and, about 10 yr later, by the International Society of Soil Science (Simonson, 1993). Since then, Munsell Soil Color Charts (Munsell Color, 1975) have been systematically used by pedologists. Visual estimation of soil color, however, is subject to substantial error due to various psychophysical and physical factors. For this reason, the use of colorimeters and spectrophotometers has gained widespread acceptance among soil scientists as a means to measure color accurately and precisely. Moreover, different types of spectrophotometers afford the elucidation of the spectrum of light reflected by a soil illuminated in various ways. Reflectance, which is the base quantity that characterizes the process of reflection, is defined as the ratio of the reflected radiant flux (or power) to the incident radiant flux (or power) (Wyszecki and Stiles, 1982). Generally, the reflectance of a soil at any wavelength λ can be considered to be the sum of two components: regular (or specular, or mirror) reflectance and diffuse (or volume or nondirectional) reflectance (defined in more detail below). Reflectance measurements in the field are usually made on relatively large areas (>10 cm2). Under these conditions, both specular and diffuse reflectance usually contribute to the total reflectance of a soil surface, the magnitude of which depends on particle size, structure, microrelief, and other properties that define the “surface state” (Escadafal, 1989). In contrast, laboratory measurements of soil reflectance are usually made on small areas (<10 cm2) of disturbed soil materials that are usually sieved or ground to a small size. In this case diffuse reflectance predominates, which depends mainly on soil composition. This chapter describes available laboratory methods for recording diffuse reflectance spectra for soil materials and ways to handle the information to identify and characterize soil minerals. Only the visible and narrow vicinal ultraviolet (UV) and infrared (IR) regions of the spectrum are considered here because reflectance in the IR region is the subject of another chapter (Johnston and Aochi, 1996)).

Variation of the group 5 grass pollen allergen content of airborne pollen in relation to geographic location and time in season.

Abstract: Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergens from pollen. Objective: We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. Methods: Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-volume cascade impactor at 10 sites across Europe for 3 consecutive years. Group 5 allergen was determined with a Phl p 5 specific ELISA in two fractions of ambient air: Particulate Matter (PM) >10μm and 10μm>PM>2.5μm. Mediator release by ambient air was determined in FceR1-humanized basophils. Origin of pollen was modeled and condensed to pollen potency maps. Results: On average grass pollen released 2.3 pg Phl p 5/pollen. Allergen release per pollen (potency) varied substantially, ranging from 0 to 9 pg Phl p 5/pollen (5 to 95% percentile). The main variation was locally day-to-day. Average potency maps across Europe varied between years. Mediator release from basophilic granulocytes correlated better with allergen/m3 (r2=0.80, p<0.001) than with pollen/m3 (r2=0.61, p<0.001). In addition, pollen released different amounts of allergen in the nonpollen bearing fraction of ambient air depending on humidity. Conclusion: Across Europe, the same amount of pollen released substantially different amounts of group 5 grass pollen allergen. This variation in allergen release is on top of variations in pollen counts. Molecular aerobiology, i.e. determining allergen in ambient air, may be a valuable addition to pollen counting.

Contemporary practice and technical aspects in coronary intervention with bioresorbable scaffolds: A European perspective

Abstract: Aims Next to patient characteristics, the lack of a standardised approach for bioresorbable vascular scaffold (BVS) implantation is perceived as a potential explanation for the heterogeneous results reported so far To provide some guidance, we sought to find a consensus on the best practices for BVS implantation and management across a broad array of patient and lesion scenarios Methods and results Fourteen European centres with a high volume of BVS procedures combined their efforts in an informal collaboration To get the most objective snapshot of different practices among the participating centres, a survey with 45 multiple choice questions was prepared and conducted The results of the survey represented a basis for the technical advice provided in the document, whereas areas of controversy are highlighted Conclusions Consensus criteria for patient and lesion selection, BVS implantation and optimisation, use of intravascular imaging guidance, approach to multiple patient and lesion scenarios, and management of complications, were identified

Intransitive competition is widespread in plant communities and maintains their species richness

Abstract: Intransitive competition networks, those in which there is no single best competitor, may ensure species coexistence. However, their frequency and importance in maintaining diversity in realworld ecosystems remain unclear. We used two large data sets from drylands and agricultural grasslands to assess: (1) the generality of intransitive competition, (2) intransitivity–richness relationships and (3) effects of two major drivers of biodiversity loss (aridity and land-use intensification) on intransitivity and species richness. Intransitive competition occurred in > 65% of sites and was associated with higher species richness. Intransitivity increased with aridity, partly buffering its negative effects on diversity, but was decreased by intensive land use, enhancing its negative effects on diversity. These contrasting responses likely arise because intransitivity is promoted by temporal heterogeneity, which is enhanced by aridity but may decline with land-use intensity. We show that intransitivity is widespread in nature and increases diversity, but it can be lost with environmental homogenisation.

Can we expand the indications for laparoscopic liver resection? A systematic review and meta-analysis of laparoscopic liver resection for patients with hepatocellular carcinoma and chronic liver disease.

Abstract: Liver resection (LR) for patients with hepatocellular carcinoma (HCC) and chronic liver disease (CLD) poses a high risk of serious postoperative complications and multicentric metachronous lesions requiring repeated treatment. The efficacy of laparoscopic LR (LLR) for such patients has yet to be established. The objective of this study is to test the outcomes of LLR for HCC with the aim of considering potential expansion of the indications for LLR. We performed a systematic review of the pertinent English-language literature. Our search yielded four meta-analyses and 23 comparative studies of LLR for HCC. On the basis of the findings from these studies and our newly conducted meta-analysis, the possibility for expanding the indications for LLR to HCC was examined. The studies show that LLR (vs open) for HCC generally yields better short-term outcomes without compromising long-term outcomes, and that incidences of postoperative ascites and liver failure are decreased with LLR. Several studies show the benefits of LLR for patients with severe CLD and for repeat surgery. Reductions of postoperative ascites and liver failure are among the advantages of LLR. These characteristics of LLR may allow us to expand the indications of LLR to HCC with CLD.

A semi-supervised system for weed mapping in sunflower crops using unmanned aerial vehicles and a crop row detection method

Abstract: Graphical abstractDisplay Omitted HighlightsThe problem of constructing a weed mapping model via machine learning techniques is assessedThe combination of spectral properties with vegetation indexes and crop rows helps the predictionA semi-supervised classifier has been proved to perform well for the classification problem assessed with very few information provided by the userAn extended experimental design for weed mapping could be performed considering other crops This paper presents a system for weed mapping, using imagery provided by unmanned aerial vehicles (UAVs) Weed control in precision agriculture is based on the design of site-specific control treatments according to weed coverage A key component is precise and timely weed maps, and one of the crucial steps is weed monitoring, by ground sampling or remote detection Traditional remote platforms, such as piloted planes and satellites, are not suitable for early weed mapping, given their low spatial and temporal resolutions Nonetheless, the ultra-high spatial resolution provided by UAVs can be an efficient alternative The proposed method for weed mapping partitions the image and complements the spectral information with other sources of information Apart from the well-known vegetation indexes, which are commonly used in precision agriculture, a method for crop row detection is proposed Given that crops are always organised in rows, this kind of information simplifies the separation between weeds and crops Finally, the system incorporates classification techniques for the characterisation of pixels as crop, soil and weed Different machine learning paradigms are compared to identify the best performing strategies, including unsupervised, semi-supervised and supervised techniques The experiments study the effect of the flight altitude and the sensor used Our results show that an excellent performance is obtained using very few labelled data complemented with unlabelled data (semi-supervised approach), which motivates the use of weed maps to design site-specific weed control strategies just when farmers implement the early post-emergence weed control

Benefits of Chromium Substitution in Na3V2(PO4)3 as a Potential Candidate for Sodium‐Ion Batteries

Abstract: The effect of low-level chromium substitution in Na3V2-xCrx(PO4)3 (0≤x≤0.4), a potential cathode material in Na-ion cells, has been examined. A suitable synthesis procedure is developed to obtain composites of crystalline NASICON phosphate and an amorphous carbon phase to enhance the electrical conductivity of the electrode. The optimized cathode materials were characterized by using X-ray diffraction and spectroscopic techniques. The electrochemical evaluation was carried out by using galvanostatic and potentiostatic methods. The activity of the V5+/V4+ redox couple at approximately 4 V is remarkable for the samples containing chromium. A reversible capacity of 107 mAh g−1 with a coulombic efficiency of 99 % was determined for Na3V1.9Cr0.1(PO4)3 after 40 cycles. The observed performance correlates with a good kinetic response, resulting from low charge-transfer resistance and high diffusion coefficient.