680 research outputs found
Stochastic algorithms for discontinuous multiplicative white noise
Stochastic differential equations with multiplicative noise need a mathematical prescription due to different interpretations of the stochastic integral. This fact implies specific algorithms to perform numerical integrations or simulations of the stochastic trajectories. Moreover, if the multiplicative noise function is not continuous then the standard algorithms cannot be used. We present an explicit algorithm to avoid this problem and we apply it to a well controlled example. Finally, we discuss on the existence of higher-order algorithms for this specific situation
SYT mutations membrane fusions with whole plant hypersensitivity to abiotic stresses
Plants undergo continuous exposure to various abiotic stresses in their natural environment. For this reason they have evolved intricate mechanisms to perceive external signals and trigger the physiological changes necessary to adapt and survive under such conditions. The plasma membrane is a physical barrier that separates the intracellular and extracellular environments and its integrity is essential for stress tolerance. Here we present a role for plant synaptotagmins in plasma membrane integrity maintenance through Vesicle-PM fusions. We also evaluate the physiological consequences of the SYT depletion under several abiotic stress conditions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Comparing university performance by legal status: a Malmquist-type index approach for the case of the Spanish higher education system
This is an Accepted Manuscript of an article published by Taylor & Francis in Tertiary Education and Management on 2017, available online: http://www.tandfonline.com/10.1080/13583883.2017.1296966New public management and increasing levels of competition driven by global rankings are bringing the managerial practices of public and private higher education institutions closer together. However, these two types of institutions still maintain different objectives and traditions and enjoy different degrees of autonomy that are reflected in their internal organisational structures. We study the relative efficiency and productivity performance of private and public universities in Spain through two adaptations of the Malmquist Index. Results show that, in 2009/2010, the greater flexibility of private universities meant a better adjustment between inputs and outputs in the private sector. However, in 2013/2014, public universities had caught up with private universities. Because of the economic crisis, the inputs of public universities have decreased, but this decrease had not fully impacted their results in 2013/201
Effect of Preventive Chlamydia abortus Vaccination in Offspring Development in Sheep Challenged Experimentally
Ovine enzootic abortion, caused by Chlamydia abortus, leads to important economic losses worldwide. In addition to reproductive failures, infection may impact lamb growth during the first weeks after birth, yet this effect has not been well characterized. Vaccination can help to control the disease but variable efficacy values have been described, possibly related with factors associated with the host, the vaccine, the parameter used for efficacy determination and the challenge conditions. In this context, we evaluated the efficacy of an inactivated standard commercial vaccine and a 1/2 diluted dose in pregnant sheep challenged with C. abortus by examining multiple indicators ofvaccine effect (including incidence of reproductive failures, bacterial excretion, and evolution of weight gain of viable lambs during the first month of life). Three groups of ewes [control non-vaccinated, C (n = 18); vaccinated with standard dose, SV (n = 16) and vaccinated with 1/2 dose, DV (n = 17)], were challenged approximately 90 days post-mating and tested using direct PCR (tissue samples and vaginal swabs) and ELISA (serum) until 31 days post-reproductive outcome. There were not significant differences in the proportions of reproductive failures or bacterial shedding after birth/abortion regardless the vaccination protocol. However, a beneficial effect of vaccination on offspring growth was detected in both vaccinated groups compared with the controls, with a mean increase in weight measured at 30 days of life of 1.5 and 2.5 Kg (p = 0.056) and an increase in the geometric mean of the daily gain of 8.4 and 9.7% in lambs born from DV and SV ewes compared to controls, respectively. Our results demonstrate the effect of an inactivated vaccine in the development of the offspring of C. abortus-infected ewes at a standard and a diluted dose, an interesting finding given the difficulty in achieving sufficient antigen concentration in the production of EAE-commercial vaccines
Insights into the speleogenesis of Ejulve cave (Iberian Range, NE Spain): quaternary hydrothermal karstification?
We provide first insights into the speleogenesis of Ejulve cave (Teruel province, Iberian Range, NE Spain) by studying cave morphologies and cave deposits, combined with regional geomorphological and hydrothermal observations. Three main hydrogeomorphic evolutionary stages can be distinguised to explain the origin and evolution of the Ejulve endokarstic system. Cave pattern and cave solutional features (calcite vein fillings, tubes with rising ceiling cupolas, pendants and cusps, spongework and micro-corrosion features) suggest that the cave generated in a phreatic environment by ascending water. Cave morphologies and regional hydrothermal springs in this region suggest, but not prove, the involvement of thermal waters and related convection and condensation-corrosion mechanisms in the origin of the cave. Subsequently, the cave underwent a change to epigenic conditions driven by denudation, as a result of regional uplift. Once the karstic system was exhumated, carbonate speleothems formed in a vadose environment. Mineralogical, petrographic, isotopic and chronological (U-series dating) analyses of carbonate speleothems (i.e. stalagmites, flowstones, botryoids, spars, acicular crystals and farmed carbonate) are provided. Calcite, high-Mg calcite and aragonite are the most common minerals, whereas columnar, dendritic, micrite, mosaics and fans are the main fabrics. Mean delta O-18 values of - 7.3 parts per thousand and delta C-13 values of - 9.1 parts per thousand indicate carbonate precipitation from meteoric waters without a hydrothermal origin. Carbonate deposits formed at least since 650 ka BP. Our study suggests that hydrothermal fluid flow may explain, although the evidences are not fully conclusive, the speleogenesis of this cave
Are congenital malformations more frequent in fetuses with intrahepatic persistent right umbilical vein? A comparative study
Objective Persistent right umbilical vein (PRUV) is a vascular anomaly where the right umbilical vein remains as the only conduit that returns oxygenated blood to the fetus. It has classically been described as associated with numerous defects. We distinguish the intrahepatic variant (better prognosis) and the extrahepatic variant (associated with worse prognosis). The objective of this study was to compare rates of congenital malformations in fetuses with intrahepatic PRUV (I-PRUV) versus singleton pregnancies without risk factors. Materials and Methods A multicenter, crossover design, comparative study was performed between 2003 and 2013 on fetuses diagnosed with I-PRUV (n = 56), and singleton pregnancies without congenital malformation risk factors (n = 4050). Results Fifty-six cases of I-PRUV were diagnosed (incidence 1:770). A statistically significant association between I-PRUV and the presence of congenital malformations (odds ratio 4.321; 95% confidence interval 2.15–8.69) was found. This positive association was only observed with genitourinary malformations (odds ratio 3.038; 95% confidence interval 1.08–8.56). Conclusion Our rate of malformations associated with I-PRUV (17.9%) is similar to previously published rates. I-PRUV has shown a significant increase in the rate of associated malformations, although this association has only been found to be statistically significant in the genitourinary system. Noteworthy is the fact that this comparative study has not pointed to a significant increase in the congenital heart malformation rate. Diagnosis of isolated I-PRUV does not carry a worse prognosis
Protein misfolding and clearance in the pathogenesis of a new infantile onset ataxia caused by mutations in PRDX3
Pathogenesis; Ataxia; MutationsPatogénesis; Ataxia; MutacionesPatogènesi; Atàxia; MutacionsPeroxiredoxin 3 (PRDX3) encodes a mitochondrial antioxidant protein, which is essential for the control of reactive oxygen species homeostasis. So far, PRDX3 mutations are involved in mild-to-moderate progressive juvenile onset cerebellar ataxia. We aimed to unravel the molecular bases underlying the disease in an infant suffering from cerebellar ataxia that started at 19 months old and presented severe cerebellar atrophy and peripheral neuropathy early in the course of disease. By whole exome sequencing, we identified a novel homozygous mutation, PRDX3 p.D163E, which impaired the mitochondrial ROS defense system. In mouse primary cortical neurons, the exogenous expression of PRDX3 p.D163E was reduced and triggered alterations in neurite morphology and in mitochondria. Mitochondrial computational parameters showed that p.D163E led to serious mitochondrial alterations. In transfected HeLa cells expressing the mutation, mitochondria accumulation was detected by correlative light electron microscopy. Mitochondrial morphology showed severe changes, including extremely damaged outer and inner membranes with a notable cristae disorganization. Moreover, spherical structures compatible with lipid droplets were identified, which can be associated with a generalized response to stress and can be involved in the removal of unfolded proteins. In the patient’s fibroblasts, PRDX3 expression was nearly absent. The biochemical analysis suggested that the mutation p.D163E would result in an unstable structure tending to form aggregates that trigger unfolded protein responses via mitochondria and endoplasmic reticulum. Altogether, our findings broaden the clinical spectrum of the recently described PRDX3-associated neurodegeneration and provide new insight into the pathological mechanisms underlying this new form of cerebellar ataxia.The Instituto de Salud Carlos III (ISCIII)—Subdirección General de Evaluación y Fomento de la Investigación within the framework of the National R + D + I Plan co-funded with European Regional Development Funds (ERDF) (grants PI18/00147 and PI21/00103 to C.E.); the Spanish Ministry of Economy and Competitiveness (grant SAF2017-89020-R to P.F.); the Fundació La Marató TV3 (grants 20143130 and 20143131 to B.P.-D. and C.E.) and the Generalitat Valenciana (grant PROMETEO/2018/135 to C.E.). Part of the equipment employed in this work was funded by Generalitat Valenciana and co-financed with ERDF (OP ERDF of Comunitat Valenciana 2014-2020). P.F. and A.R.-P. are supported by the Spanish Ministry of Science and Innovation (grants RyC-2014-16410 to P.F. and PRE2018-083562 to A.R.-P.)
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