Efecto del estrés hídrico a distintas temperaturas sobre la germinación de semillas de Bulnesia retama (Gill. ex. Hook.) Griseb. -Zigofiláceas - en San Luis, Argentina

Se estudió la germinación de semillas de Bulnesia retama frente a condiciones de estrés hídrico, simulado con PEG6000 a distintas temperaturas, y su recuperación ante el estrés. Las semillas recolectadas en San Luis (Argentina) se colocaron a germinar en bolsas de polietileno, con soluciones de PEG6000, para simular potenciales agua: 0 (Control con agua destilada); -0,25; -0,5; -0,75; -1; -1,25 y -1,5 MPa en estufa de cultivo y en oscuridad a temperaturas de 18º, 25º y 32 ºC. Las semillas que no germinaron ante el estrés simulado fueron lavadas y colocadas a germinar nuevamente en agua destilada a 25 ºC. Se registró el porcentaje y la velocidad de germinación de las semillas. Las semillas colocadas en agua destilada germinaron con porcentajes superiores al 70% en el rango de 18º a 32 ºC sin diferencias entre temperaturas. A 18 ºC, el porcentaje y la velocidad de germinación disminuyeron significativamente en todos los tratamientos con PEG, mientras que a 25 ºC la respuesta germinativa fue afectada a partir de -1 MPa. A 32 ºC la germinación no difirió del control en las primeras 48 horas hasta potenciales osmóticos de -1 MPa, pero luego la velocidad y porcentaje de germinación disminuyeron significativamente. El porcentaje de germinación en la recuperación después del estrés fue similar al porcentaje del control original, lo que demuestra que las semillas no germinan si no tienen determinadas condiciones hídricas y térmicas. Estos resultados pueden ser el resultado de la adaptación de la especie a las condiciones ambientales propias de la región.Se estudió la germinación de semillas de Bulnesia retama frente a condiciones de estrés hídrico, simulado con PEG6000 a distintas temperaturas, y su recuperación ante el estrés. Las semillas recolectadas en San Luis (Argentina) se colocaron a germinar en bolsas de polietileno, con soluciones de PEG6000, para simular potenciales agua: 0 (Control con agua destilada); -0,25; -0,5; -0,75; -1; -1,25 y -1,5 MPa en estufa de cultivo y en oscuridad a temperaturas de 18º, 25º y 32 ºC. Las semillas que no germinaron ante el estrés simulado fueron lavadas y colocadas a germinar nuevamente en agua destilada a 25 ºC. Se registró el porcentaje y la velocidad de germinación de las semillas. Las semillas colocadas en agua destilada germinaron con porcentajes superiores al 70% en el rango de 18º a 32 ºC sin diferencias entre temperaturas. A 18 ºC, el porcentaje y la velocidad de germinación disminuyeron significativamente en todos los tratamientos con PEG, mientras que a 25 ºC la respuesta germinativa fue afectada a partir de -1 MPa. A 32 ºC la germinación no difirió del control en las primeras 48 horas hasta potenciales osmóticos de -1 MPa, pero luego la velocidad y porcentaje de germinación disminuyeron significativamente. El porcentaje de germinación en la recuperación después del estrés fue similar al porcentaje del control original, lo que demuestra que las semillas no germinan si no tienen determinadas condiciones hídricas y térmicas. Estos resultados pueden ser el resultado de la adaptación de la especie a las condiciones ambientales propias de la región

Enhanced plasmonic behavior of bimetallic (Ag-Au) multilayered spheres

In this article we study the plasmonic behavior of some stable, highly biocompatible bimetallic metal-dielectric-metal (MDM) and double concentric nanoshell (DCN) structures. By simply switching the material of the inner structure from Au to Ag, the intensity of their surface plasmon resonance could be increased in the optical transparency region of the human tissues up to 20 and 60 percent for the MDM and DCN, respectively, while the biocompatibility is retained. The obtained results indicate that these novel structures could be highly suitable for surface enhanced Raman scattering and photothermal cancer therapy

Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

<div><p>Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway <i>i</i>.<i>e</i>., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times <i>vs</i>. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.</p></div

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

Accelerating magnetic induction tomography‐based imaging through heterogeneous parallel computing

Magnetic Induction Tomography (MIT) is a non‐invasive imaging technique, which has applications in both industrial and clinical settings. In essence, it is capable of reconstructing the electromagnetic parameters of an object from measurements made on its surface. With the exploitation of parallelism, it is possible to achieve high quality inexpensive MIT images for biomedical applications on clinically relevant time scales. In this paper we investigate the performance of different parallel implementations of the forward eddy current problem, which is the main computational component of the inverse problem through which measured voltages are converted into images. We show that a heterogeneous parallel method that exploits multiple CPUs and GPUs can provide a high level of parallel scaling, leading to considerably improved runtimes. We also show how multiple GPUs can be used in conjunction with deal.II, a widely‐used open source finite element library

A global perspective on marine photosynthetic picoeukaryote community structure

A central goal in ecology is to understand the factors affecting the temporal dynamics and spatial distribution of microorganisms and the underlying processes causing differences in community structure and composition. However, little is known in this respect for photosynthetic picoeukaryotes (PPEs), algae that are now recognised as major players in marine CO2 fixation. Here, we analysed dot blot hybridisation and cloning–sequencing data, using the plastid-encoded 16S rRNA gene, from seven research cruises that encompassed all four ocean biomes. We provide insights into global abundance, α- and β-diversity distribution and the environmental factors shaping PPE community structure and composition. At the class level, the most commonly encountered PPEs were Prymnesiophyceae and Chrysophyceae. These taxa displayed complementary distribution patterns, with peak abundances of Prymnesiophyceae and Chrysophyceae in waters of high (25:1) or low (12:1) nitrogen:phosphorus (N:P) ratio, respectively. Significant differences in phylogenetic composition of PPEs were demonstrated for higher taxonomic levels between ocean basins, using Unifrac analyses of clone library sequence data. Differences in composition were generally greater between basins (interbasins) than within a basin (intrabasin). These differences were primarily linked to taxonomic variation in the composition of Prymnesiophyceae and Prasinophyceae whereas Chrysophyceae were phylogenetically similar in all libraries. These data provide better knowledge of PPE community structure across the world ocean and are crucial in assessing their evolution and contribution to CO2 fixation, especially in the context of global climate change

The p.(Cys150Tyr) variant in CSRP3 is associated with late-onset hypertrophic cardiomyopathy in heterozygous individuals

INTRODUCTION AND OBJECTIVES: Up to 50% of patients with hypertrophic cardiomyopathy (HCM) show no disease-causing variants in genetic studies. Mutations in CSRP3 have been associated with HCM, but evidence supporting pathogenicity is inconclusive. In this study, we describe an HCM cohort with a missense variant in CSRP3 (p.Cys150Tyr) with supporting evidence for pathogenicity and a description of the associated phenotype. METHODS: CSRP3 was sequenced in 6456 index cases with a diagnosis of HCM and in 5012 probands with other cardiomyopathies. In addition, 3372 index cases with hereditary cardiovascular disorders other than cardiomyopathies (mainly channelopathies and aortopathies) were used as controls. RESULTS: The p.(Cys150Tyr) variant was identified in 11 unrelated individuals of the 6456 HCM probands, and it was not identified in patients with other cardiomyopathies (p < 0.0001) or in our control population (p < 0.0001). Ten of the index cases were heterozygous and one was homozygous. Homozygous had a more severe phenotype. Family screening identified 17 other carriers. Wild-type individuals showed no signs of disease. The mean age at diagnosis of affected individuals was 55 ± 13 years, and the mean left ventricular wall thickness was 18 ± 3 mm. The variant showed highly age-dependent penetrance. After a mean follow-up of 11 (±8) years, no adverse events were reported in any of the HCM patients. CONCLUSIONS: The p.(Cys150Tyr) variant in CSRP3 causes late-onset and low risk form of hypertrophic cardiomyopathy in heterozygous carriers

The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

Comparison of the impact of atrial fibrillation on the risk of early death after stroke in women versus men

BACKGROUND: Atrial fibrillation (AF) is considered a predictive factor of poor clinical outcome in patients with an ischemic stroke (IS). This study addressed whether the impact of AF on the in-hospital mortality after first ever IS is different according to the patient’s gender. METHODS: We prospectively studied 1678 patients with first ever IS consecutively admitted to two University Hospitals. We recorded demographic data, vascular risk factors, and the stroke severity (NIHSS) at admission analyzing their impact on the in-hospital mortality and on the combined mortality-dependency at discharge using a Cox proportional hazards model. Two variable interactions between those factors independently related to in-hospital mortality and combined mortality-dependency at discharge were tested. RESULTS: Overall in-hospital mortality was 11.3%. Cox proportional hazards model showed that NIHSS at admission (HR: 1.178 [95% CI 1.149–1.207]), age (HR: 1.044 [95% CI 1.026–1.061]), AF (HR: 1.416 [95% CI 1.048–1.913]), male gender (HR: 1.853 [95% CI 1.323–2.192) and ischemic heart disease (HR: 1.527 [95% CI 1.063–2.192]) were independent predictors of in-hospital mortality. A significant interaction between gender and AF was found (p = 0.017). Data were stratified by gender, showing that AF was an independent predictor of poor outcome just for woman (HR: 2.183 [95% CI 1.403–3.396]; p < 0.001). The independent predictors of combined mortality-disability at discharge were NIHSS at admission (HR: 1.052 [95% CI 1.041–1.063]), age (HR: 1.011 [95% CI 1.004–1.018]), AF (HR: 1.197 [95% CI 1.031–1.390]), ischemic heart disease (HR: 1.222 [95% CI 1.004–1.488]), and smoking (HR: 1.262 [95% CI 1.033–1.541]). CONCLUSIONS: The impact of AF is different in the twogenders and appears as a specific ischemic stroke predictor of in-hospital mortality just for women

Phytochemicals as antibiotic alternatives to promote growth and enhance host health

There are heightened concerns globally on emerging drug-resistant superbugs and the lack of new antibiotics for treating human and animal diseases. For the agricultural industry, there is an urgent need to develop strategies to replace antibiotics for food-producing animals, especially poultry and livestock. The 2nd International Symposium on Alternatives to Antibiotics was held at the World Organization for Animal Health in Paris, France, December 12-15, 2016 to discuss recent scientific developments on strategic antibiotic-free management plans, to evaluate regional differences in policies regarding the reduction of antibiotics in animal agriculture and to develop antibiotic alternatives to combat the global increase in antibiotic resistance. More than 270 participants from academia, government research institutions, regulatory agencies, and private animal industries from >25 different countries came together to discuss recent research and promising novel technologies that could provide alternatives to antibiotics for use in animal health and production; assess challenges associated with their commercialization; and devise actionable strategies to facilitate the development of alternatives to antibiotic growth promoters (AGPs) without hampering animal production. The 3-day meeting consisted of four scientific sessions including vaccines, microbial products, phytochemicals, immune-related products, and innovative drugs, chemicals and enzymes, followed by the last session on regulation and funding. Each session was followed by an expert panel discussion that included industry representatives and session speakers. The session on phytochemicals included talks describing recent research achievements, with examples of successful agricultural use of various phytochemicals as antibiotic alternatives and their mode of action in major agricultural animals (poultry, swine and ruminants). Scientists from industry and academia and government research institutes shared their experience in developing and applying potential antibiotic-alternative phytochemicals commercially to reduce AGPs and to develop a sustainable animal production system in the absence of antibiotics.Fil: Lillehoj, Hyun. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Liu, Yanhong. University of California; Estados UnidosFil: Calsamiglia, Sergio. Universitat Autònoma de Barcelona; EspañaFil: Fernandez Miyakawa, Mariano Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; ArgentinaFil: Chi, Fang. Amlan International; Estados UnidosFil: Cravens, Ron L.. Amlan International; Estados UnidosFil: Oh, Sungtaek. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Gay, Cyril G.. United States Department of Agriculture. Agricultural Research Service; Argentin