Effects of the time of drought occurrence on growth of Pinus taeda L seedlings

Pinus taeda L. es una especie de importancia comercial a nivel mundial y en Argentina en particular, donde ocupa el primer lugar en superficie implantada. En el marco del cambio climático se predice una mayor frecuencia de eventos de sequía en su región de cultivo, lo que se sobreimpone a la expansión de la misma a suelos con menor capacidad de retención hídrica. Existen antecedentes acerca de su respuesta al estrés hídrico, aunque se desconoce el efecto del momento de ocurrencia del mismo, aspecto que fue evaluado en el presente estudio. Además de la situación control, se impuso estrés hídrico a plantines por restricción del riego al inicio y al final de la primavera, y en verano. Se midió periódicamente el crecimiento en altura y diámetro basal del tallo, y al final del ensayo se analizó la producción y partición de biomasa aérea, y la anatomía de las hojas. Durante la primavera se determinaron el potencial hídrico foliar, la conductancia estomática (gs), la capacidad fotosintética, la conductividad hidráulica específica de ramas (ks) y la capacidad de ajuste osmótico. El déficit de agua en el suelo durante la primavera afectó negativamente el crecimiento en altura y diámetro, con distinta capacidad de recuperación en función del momento de ocurrencia del estrés. El estrés en verano no afectó el crecimiento. La disminución del crecimiento en primavera se vio acompañada por cambios a nivel foliar (Amax, gs, tamaño y densidad de estomas), pero sin cambios en la partición de biomasa entre estructuras aéreas,potencial osmótico y en la ks, que impliquen cambios en la arquitectura hidráulica de las plantas.Pinus taeda L. is a commercially important species globally and in Argentina in particular, which ranks first in planted area. In the context of climate change a higher frequency of drought events is predicted in its cultivation region, which is superimposed to its expansion to areas with soils with lower water retention capacity. There is knowledge about the species ́ response to water stress, although it is unknown the effect of the time of occurrence of drought within the growing season, which is the topic evaluated in this study. In addition to control plants, water stress was imposed to other seedlings by restricting watering at the beginning and end of the spring and in summer. Height and stem basal diameter growth was measured periodically. At the end of the experiment, production and biomass partitioning and leaf anatomy were analyzed. During spring, physiological variables such as water potential, stomatal conductance (gs), photosynthesis, branch specific hydraulic conductivity (ks) and osmotic adjustment were determined. The soil water deficit during spring had a marked negative effect on growth with differential resilience depending on the time of stress occurrence. Summer stress did not affect growth. The growth decrease in spring was accompanied by stomatal changes (gs, stomatal size and density). However, no changes were observed in the partitioning of biomass between aerial structures, osmotic potential and ks, suggesting that spring drought did not result in significant changes in the plant hydraulic architecture.Fil: Bulfe, Nardia M. L.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Fernandez, Maria Elena. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Rating the Raters: Evaluating how ESG Rating Agencies Integrate Sustainability Principles

Environmental, social, and governance (ESG) rating agencies, acting as relevant financial market actors, should take a stand on working towards achieving a more sustainable development. In this context, the objective of this paper is, on the one hand, to understand how criteria used by ESG rating agencies in their assessment processes have evolved over the last ten years and, on the other hand, to analyze whether ESG rating agencies are contributing to fostering sustainable development by the inclusion of sustainability principles into their assessment processes and practices according to the ESG criteria. This research is based on a comparative descriptive analysis of the public information provided by the most representative ESG rating and information provider agencies in the financial market in two periods: 2008 and 2018. The findings show that ESG rating agencies have integrated new criteria into their assessment models to measure corporate performance more accurately and robustly in order to respond to new global challenges. However, a deep analysis of the criteria also shows that ESG rating agencies do not fully integrate sustainability principles into the corporate sustainability assessment process

Zircon geochronology of intrusive rocks from Cap de Creus, eastern Pyrenees

New petrological and U–Pb zircon geochronological information has been obtained from intrusive plutonic rocks and migmatites from the Cap de Creus massif (Eastern Pyrenees) in order to constrain the timing of the thermal and tectonic evolution of this northeasternmost segment of Iberia during late Palaeozoic time. Zircons from a deformed syntectonic quartz diorite from the northern Cap de Creus Tudela migmatitic complex yield a mean age of 298.8±3.8 Ma. A syntectonic granodiorite from the Roses pluton in the southern area of lowest metamorphic grade of the massif has been dated at 290.8±2.9 Ma. All the analysed zircons from two samples of migmatitic rocks yield inherited ages from the Precambrian metasedimentary protolith (with two main age clusters at c. 730–542 Ma and c. 2.9–2.2 Ga). However, field structural relationships indicate that migmatization occurred synchronously with the emplacement of the quartz dioritic magmas at c. 299 Ma. Thus, the results of this study suggest that subduction-related calc-alkaline magmatic activity in the Cap de Creus was coeval and coupled with D2 dextral transpression involving NNW–SSE crustal shortening during Late Carboniferous – Early Permian time (c. 299–291 Ma). Since these age determinations are within the range of those obtained for undeformed (or slightly deformed) calc-alkaline igneous rocks from NE Iberia, it follows that the Cap de Creus massif would represent a zone of intense localization of D2 transpression and subsequent D3 ductile wrenching that extended into the Lower Permian during a transitional stage between the Variscan and Cimmerian cycles

Cluster expansion in the canonical ensemble

We consider a system of particles confined in a box \La\subset\R^d interacting via a tempered and stable pair potential. We prove the validity of the cluster expansion for the canonical partition function in the high temperature - low density regime. The convergence is uniform in the volume and in the thermodynamic limit it reproduces Mayer's virial expansion providing an alternative and more direct derivation which avoids the deep combinatorial issues present in the original proof

Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy

Rostral floor plate (flexural organ) secretes glycoproteins immunologically similar to subcommissural organ glycoproteins in dogfish (Scyliorhinus canicula) embryos

The subcommissural organ of vertebrates secretes glycoproteins into the cerebrospinal fluid of the third cerebral ventricle. This material polymerizes in Reissner's fiber. During ontogenetic development, besides the subcommissural organ, the ependyma lining the pontine flexure constitutes an additional Reissner's fiber-secreting gland named flexural organ. We have studied the secretion of the flexural organ and the subcommissural organ in dogfish (Scyliorhinus canicula) embryos using three different antisera and the lectins concanavalin A and wheat germ agglutinin. AFRU is an antiserum against the bovine Reissner's fiber; Ab-600 is an antiserum against 600 kDa dogfish subcommissural organ glycoproteins; and APSO is an antiserum against immunoaffinity purified bovine subcommissural organ secretory glycoproteins. These three antisera immunostained the flexural organ indicating that it contains epitopes similar to those present in bovine and dogfish subcommissural organ glycoproteins. It seems highly probable that the flexural or an and the subcommissural organ of dogfish embryos secrete similar compound(s). Other ependymal regions were also immunostained with Ab-600 and APSO antisera. Then, Reissner's fiber-like glycoproteins were transiently expressed by most embryonary ependymal cells. These glycoproteins might play a role in the development of the central nervous system of vertebrates. (C) 1997 Elsevier Science B.V

Identification of Reissner's fiber-like glycoproteins in two species of freshwater planarians (Tricladida), by use of specific polyclonal and monoclonal antibodies

By using one polyclonal antiserum raised against bovine Reissner's fiber and seven monoclonal antibodies raised against bovine Reissner's fiber and against immunopurified bovine subcommissural organ glycoproteins, we have investigated two freshwater planarian species (Girardia tigrina, Schmidtea mediterranea) by light- and electron-microscopic immunocytochemistry. ELISA probes showed that the monoclonal antibodies recognized different, nonoverlapping, unrepeated, proteinaceous epitopes present in the same compounds of bovine Reissner's fiber. Cells immunoreactive to the polyclonal and monoclonal antibodies were found in the dorsal and ventral integument of both planarian species. Labeled cuboid epidermal cells bore cilia and displayed several types of secretory granules; they were covered by a film of immunoreactive material. Studies on adjacent thin and semithin sections revealed coexistence of label in the same regions and in the same cells when two different monoclonal antibodies were used. These results indicate that a secretory substance immunologically similar to the secretion of the vertebrate subcommissural organ is present in primitive tripoblasts such as planarians, suggesting that these secretions are ancient and well conserved in phylogeny

Hot topics, urgent priorities, and ensuring success for racial/ethnic minority young investigators in academic pediatrics.

BackgroundThe number of racial/ethnic minority children will exceed the number of white children in the USA by 2018. Although 38% of Americans are minorities, only 12% of pediatricians, 5% of medical-school faculty, and 3% of medical-school professors are minorities. Furthermore, only 5% of all R01 applications for National Institutes of Health grants are from African-American, Latino, and American Indian investigators. Prompted by the persistent lack of diversity in the pediatric and biomedical research workforces, the Academic Pediatric Association Research in Academic Pediatrics Initiative on Diversity (RAPID) was initiated in 2012. RAPID targets applicants who are members of an underrepresented minority group (URM), disabled, or from a socially, culturally, economically, or educationally disadvantaged background. The program, which consists of both a research project and career and leadership development activities, includes an annual career-development and leadership conference which is open to any resident, fellow, or junior faculty member from an URM, disabled, or disadvantaged background who is interested in a career in academic general pediatrics.MethodsAs part of the annual RAPID conference, a Hot Topic Session is held in which the young investigators spend several hours developing a list of hot topics on the most useful faculty and career-development issues. These hot topics are then posed in the form of six "burning questions" to the RAPID National Advisory Committee (comprised of accomplished, nationally recognized senior investigators who are seasoned mentors), the RAPID Director and Co-Director, and the keynote speaker.Results/conclusionsThe six compelling questions posed by the 10 young investigators-along with the responses of the senior conference leadership-provide a unique resource and "survival guide" for ensuring the academic success and optimal career development of young investigators in academic pediatrics from diverse backgrounds. A rich conversation ensued on the topics addressed, consisting of negotiating for protected research time, career trajectories as academic institutions move away from an emphasis on tenure-track positions, how "non-academic" products fit into career development, racism and discrimination in academic medicine and how to address them, coping with isolation as a minority faculty member, and how best to mentor the next generation of academic physicians