Advances in nanocatalysts design for biofuels production

The exploitation of nanocatalysts, at the boundary between homogeneous and heterogeneous catalysis, is tracking new efficient ways to produce renewable biofuels in environmentally friendly conditions. Their solid state makes them recyclable, and their nanomateric particle size enables high activities approaching those offered by homogeneous catalysts, as well as novel and unique catalytic behaviors not accessible to solids above the nanometer range. Furthermore, the use of magnetically active materials has led to the development of nanocatalysts easily recoverable through the application of magnetic fields. In this mini-review, latest achievements in the production of advanced biofuels using stable, highly active, cheap and reusable nanocatalysts are described. Specifically, biodiesel and high density fuels have been chosen as major topics of research for the design of catalytic nanomaterials

Developmental history and stress responsiveness are related to response inhibition, but not judgement bias, in a cohort of European starlings (Sturnus vulgaris)

Judgement bias tasks are designed to provide markers of affective states. A recent study of European starlings (Sturnus vulgaris) demonstrated modest familial effects on judgement bias performance, and found that adverse early experience and developmental telomere attrition (an integrative marker of biological age) both affected judgement bias. Other research has shown that corticosterone levels affect judgement bias. Here, we investigated judgement bias using a modified Go/No Go task in a new cohort of starlings (n = 31) hand-reared under different early-life conditions. We also measured baseline corticosterone and the corticosterone response to acute stress in the same individuals. We found evidence for familial effects on judgement bias, of a similar magnitude to the previous study. We found no evidence that developmental treatments or developmental telomere attrition were related to judgement bias per se. We did, however, find that birds that experienced the most benign developmental conditions, and birds with the greatest developmental telomere attrition, were significantly faster to probe the learned unrewarded stimulus. We also found that the birds whose corticosterone levels were faster to return towards baseline after an acute stressor were slower to probe the learned unrewarded stimulus. Our results illustrate the potential complexities of relationships between early-life experience, stress and affectively mediated decision making. For judgement bias tasks, they demonstrate the importance of clearly distinguishing factors that affect patterns of responding to the learned stimuli (i.e. response inhibition in the case of the Go/No Go design) from factors that influence judgements under ambiguity

The relationship of telomere length to baseline corticosterone levels in nestlings of an altricial passerine bird in natural populations

Artículo de publicación ISIBackground: Environmental stressors increase the secretion of glucocorticoids that in turn can shorten telomeres via oxidative damage. Modification of telomere length, as a result of adversity faced early in life, can modify an individual's phenotype. Studies in captivity have suggested a relationship between glucocorticoids and telomere length in developing individuals, however less is known about that relationship in natural populations. Methods: In order to evaluate the effect of early environmental stressors on telomere length in natural populations, we compared baseline corticosterone (CORT) levels and telomere length in nestlings of the same age. We collected blood samples for hormone assay and telomere determination from two geographically distinct populations of the Thorn-tailed Rayadito (Aphrastura spinicauda) that differed in brood size; nestlings body mass and primary productivity. Within each population we used path analysis to evaluate the relationship between brood size, body mass, baseline CORT and telomere length. Results: Within each distinct population, path coefficients showed a positive relationship between brood size and baseline CORT and a strong and negative correlation between baseline CORT and telomere length. In general, nestlings that presented higher baseline CORT levels tended to present shorter telomeres. When comparing populations it was the low latitude population that presented higher levels of baseline CORT and shorter telomere length. Conclusions: Taken together our results reveal the importance of the condition experienced early in life in affecting telomere length, and the relevance of integrative studies carried out in natural conditions.FONDECYT Grant 11130245 FONDECYT 1140548 USA National Science Foundation Grant IOS-0750540 ICM-005-002 PFB-23-CONICY

Progress in Understanding Harmful Algal Blooms: Paradigm Shifts and New Technologies for Research,Monitoring, and Management

The public health, tourism, fisheries, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past few decades. This has led to heightened scientific and regulatory attention, and the development of many new technologies and approaches for research and management. This, in turn, is leading to significant paradigm shifts with regard to, e.g.,our interpretation of the phytoplankton species concept (strain variation), the dogma of their apparent cosmopolitanism, the role of bacteria and zooplankton grazing in HABs, and our approaches to investigating the ecological and genetic basis for the production of toxins and allelochemicals. Increasingly,eutrophication and climate change are viewed andmanaged as multifactorial environmental stressors that will further challenge managers of coastal resources and those responsible for protecting human health. Here we review HABscience with an eye toward new concepts and approaches,emphasizing, where possible, the unexpected yet promising new directions that research has taken in this diverse field

Immune and stress responses covary with melanin-based coloration in the barn swallow

Eumelanin and pheomelanin are the main endogenous pigments in animals and melanin-based coloration has multiple functions. Melanization is associated with major life-history traits, including immune and stress response, possibly because of pleiotropic effects of genes that control melanogenesis. The net effects on pheo- versus eumelanization and other life-history traits may depend on the antagonistic effects of the genes that trigger the biosynthesis of either melanin form. Covariation between melanin-based pigmentation and fitness traits enforced by pleiotropic genes has major evolutionary implications particularly for socio-sexual communication. However, evidence from non-model organisms in the wild is limited to very few species. Here, we tested the hypothesis that melanin-based coloration of barn swallow (Hirundo rustica) throat and belly feathers covaries with acquired immunity and activation of the hypothalamic-pituitary-adrenal (HPA) axis, as gauged by corticosterone plasma levels. Individuals of both sexes with darker brownish belly feathers had weaker humoral immune response, while darker males had higher circulating corticosterone levels only when parental workload was experimentally reduced. Because color of belly feathers depends on both eu- and pheomelanin, and its darkness decreases with an increase in the concentration of eu- relative to pheomelanin, these results are consistent with our expectation that relatively more eu- than pheomelanized individuals have better immune response and smaller activation of the HPA-axis. Covariation of immune and stress response arose for belly but not throat feather color, suggesting that any function of color as a signal of individual quality or of alternative life-history strategies depends on plumage region

Gene–environment interactions increase the risk of pediatric-onset multiple sclerosis associated with ozone pollution

BackgroundWe previously reported a relationship between air pollutants and increased risk of pediatric-onset multiple sclerosis (POMS). Ozone is an air pollutant that may play a role in multiple sclerosis (MS) pathoetiology. CD86 is the only non-HLA gene associated with POMS for which expression on antigen-presenting cells (APCs) is changed in response to ozone exposure.ObjectivesTo examine the association between county-level ozone and POMS, and the interactions between ozone pollution, CD86, and HLA-DRB1*15, the strongest genetic variant associated with POMS.MethodsCases and controls were enrolled in the Environmental and Genetic Risk Factors for Pediatric MS study of the US Network of Pediatric MS Centers. County-level-modeled ozone data were acquired from the CDC's Environmental Tracking Network. Participants were assigned ozone values based on county of residence. Values were categorized into tertiles based on healthy controls. The association between ozone tertiles and having MS was assessed by logistic regression. Interactions between tertiles of ozone level and the GG genotype of the rs928264 (G/A) single nucleotide polymorphism (SNP) within CD86, and the presence of DRB1*15:01 (DRB1*15) on odds of POMS were evaluated. Models were adjusted for age, sex, genetic ancestry, and mother's education. Additive interaction was estimated using relative excess risk due to interaction (RERI) and attributable proportions (APs) of disease were calculated.ResultsA total of 334 POMS cases and 565 controls contributed to the analyses. County-level ozone was associated with increased odds of POMS (odds ratio 2.47, 95% confidence interval (CI): 1.69-3.59 and 1.95, 95% CI: 1.32-2.88 for the upper two tertiles, respectively, compared with the lowest tertile). There was a significant additive interaction between high ozone tertiles and presence of DRB1*15, with a RERI of 2.21 (95% CI: 0.83-3.59) and an AP of 0.56 (95% CI: 0.33-0.79). Additive interaction between high ozone tertiles and the CD86 GG genotype was present, with a RERI of 1.60 (95% CI: 0.14-3.06) and an AP of 0.37 (95% CI: 0.001-0.75) compared to the lowest ozone tertile. AP results indicated that approximately half of the POMS risk in subjects can be attributed to the possible interaction between higher county-level ozone carrying either DRB1*15 or the CD86 GG genotype.ConclusionsIn addition to the association between high county-level ozone and POMS, we report evidence for additive interactions between higher county-level ozone and DRB1*15 and the CD86 GG genotype. Identifying gene-environment interactions may provide mechanistic insight of biological processes at play in MS susceptibility. Our work suggests a possible role of APCs for county-level ozone-induced POMS risk