1,856 research outputs found
Sistema de consulta de notas a través de Páginas Web y de Telefonía Móvil
In this paper we are going to present a system which lets any student at Cordoba University knows what the final qualifications he has obtained in the different subjects he is registered are. The sytem lets him consult the qualifications using Internet and mobile telephony. Teachers who are reagistered in the system can upload tha qualifications without addtional software, they only need the certificate file generated by the UcoActas application. Then, all the registered students in this subject and in this service, will receive an e-mail to notify them that they can consult the qualifications. Then, they can use a Web browser or they can use a specific mobile application to consult them. Currently we are doing functionality tests with voluntary students from different courses.En este artículo se presenta un sistema que permite a cualquier alumno de la Universidad de Córdoba informarse sobre las calificaciones finales obtenidas en las asignaturas en las que está matriculado. El sistema permite consultar las notas de las actas utilizando Internet y Telefonía Móvil. Los profesores que estén dados de alta en el sistema podrán subir las notas sin necesidad de utilizar un tercer "software", directamente con el fichero de las actas generado por el programa UcoActas. Una vez subidas las notas, todos los alumnos matriculados que estén suscritos a este servicio, recibirán un e-mail con el aviso de que la consulta en la Web está disponible. Si el alumno lo desea, también podrá consultar sus notas publicadas utilizando un programa para dispositivos móviles que hará una petición segura al sistema. Actualmente se están realizando pruebas de actualización con estudiantes voluntarios de varias asignaturas
Effect of boron addition on the electrochemical properties of LiFePO4
III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce
Obtención de óxidos de hierro con propiedades fotocatalíticas mediante la transformación de residuos
ActDES- a Curated Actinobacterial Database for Evolutionary Studies
Actinobacteria is a large and diverse phylum of bacteria that contains medically and ecologically relevant organisms. Many members are valuable sources of bioactive natural products and chemical precursors that are exploited in the clinic and made using the enzyme pathways encoded in their complex genomes. Whilst the number of sequenced genomes has increased rapidly in the last 20 years, the large size, complexity and high G+C content of many actinobacterial genomes means that the sequences remain incomplete and consist of large numbers of contigs with poor annotation, which hinders large-scale comparative genomic and evolutionary studies. To enable greater understanding and exploitation of actinobacterial genomes, specialized genomic databases must be linked to high-quality genome sequences. Here, we provide a curated database of 612 high-quality actinobacterial genomes from 80 genera, chosen to represent a broad phylogenetic group with equivalent genome re-annotation. Utilizing this database will provide researchers with a framework for evolutionary and metabolic studies, to enable a foundation for genome and metabolic engineering, to facilitate discovery of novel bioactive therapeutics and studies on gene family evolution. This article contains data hosted by Microreact
The magnetically-active, low-mass, triple system WDS 19312+3607
Aims: We investigated in detail the system WDS 19312+3607, whose primary is
an active M4.5Ve star previously thought to be young (tau ~ 300-500 Ma) based
on high X-ray luminosity. Methods: We collected intermediate- and
low-resolution optical spectra taken with 2 m-class telescopes, photometric
data from the to 8 mum bands, and eleven astrometric epochs with a time
baseline of over 56 years for the two components in the system, G 125-15 and G
125-14. Results: We derived M4.5V spectral types for both stars, confirmed
their common proper motion, estimated the heliocentric distance and projected
physical separation, determined the galactocentric space velocities, and
deduced a most-probable age older than 600 Ma. We discovered that the primary,
G 125-15, is in turn an inflated, double-lined, spectroscopic binary with a
short period of photometric variability of P ~ 1.6 d, which we associated to
orbital synchronisation. The observed X-ray and Halpha emissions, photometric
variability, and abnormal radius and effective temperature of G 125-15 AB
indicate strong magnetic activity, possibly due to fast rotation. Besides, the
estimated projected physical separation between G 125-15 AB and G 125-14 of
about 1200 AU makes WDS 19312+3607 to be one of the widest systems with
intermediate M-type primaries. Conclusions: G 125-15 AB is a nearby (d ~ 26
pc), bright (J ~ 9.6 mag), active spectroscopic binary with a single
proper-motion companion of the same spectral type at a wide separation. They
are thus ideal targets for specific follow-ups to investigate wide and close
multiplicity or stellar expansion and surface cooling due to reduced convective
efficiency.Comment: A&A, in pres
Comparative genomics of the Liberibacter genus reveals widespread diversity in genomic content and positive selection history
‘Candidatus Liberibacter’ is a group of bacterial species that are obligate intracellular plant pathogens and cause Huanglongbing disease of citrus trees and Zebra Chip in potatoes. Here, we examined the extent of intra- and interspecific genetic diversity across the genus using comparative genomics. Our approach examined a wide set of Liberibacter genome sequences including five pathogenic species and one species not known to cause disease. By performing comparative genomics analyses, we sought to understand the evolutionary history of this genus and to identify genes or genome regions that may affect pathogenicity. With a set of 52 genomes, we performed comparative genomics, measured genome rearrangement, and completed statistical tests of positive selection. We explored markers of genetic diversity across the genus, such as average nucleotide identity across the whole genome. These analyses revealed the highest intraspecific diversity amongst the ‘Ca. Liberibacter solanacearum’ species, which also has the largest plant host range. We identified sets of core and accessory genes across the genus and within each species and measured the ratio of nonsynonymous to synonymous mutations (dN/dS) across genes. We identified ten genes with evidence of a history of positive selection in the Liberibacter genus, including genes in the Tad complex, which have been previously implicated as being highly divergent in the ‘Ca. L. capsica’ species based on high values of dN
Expanding Primary Metabolism Helps Generate the Metabolic Robustness To Facilitate Antibiotic Biosynthesis in Streptomyces
Abstract The expansion of the genetic repertoire of an organism by gene duplication or horizontal gene transfer (HGT) can aid adaptation. Streptomyces bacteria are prolific producers of bioactive specialized metabolites that have adaptive functions in nature and have found extensive utility in human medicine. Whilst the biosynthesis of these specialized metabolites is directed by dedicated biosynthetic gene clusters, little attention has been focussed on how these organisms have evolved robustness into their genomes to facilitate the metabolic plasticity required to provide chemical precursors for biosynthesis during the complex metabolic transitions from vegetative growth to specialized metabolite production and sporulation. Here we examine genetic redundancy in Actinobacteria and show that specialised metabolite producing bacterial families exhibit gene family expansion in primary metabolism. Focussing on a gene duplication event we show that the two pyruvate kinases in the genome of S. coelicolor arose by an ancient duplication event and that each have evolved altered enzymatic kinetics, with Pyk1 having a 20-fold higher Kcat than Pyk2 (4703 sec-1 compared to 215 sec-1 respectively) yet both are constitutively expressed. The pyruvate kinase mutants were also found to be compromised in terms of fitness when compared to wild-type Streptomyces. These data suggest that expanding gene familes can help maintain cell functionality during metabolic perturbation such as nutrient limitation and/or specialized metabolite production. Importance The rise of antimicrobial resistant infections has prompted a resurgence in interest in understanding the production of specialized metabolites by Streptomyces such as antibiotics. The presence of multiple genes encoding the same enzymatic function is an aspect of Streptomyces biology that has received little attention, however understanding how the metabolic expansion influences these organisms can help enhance production of clinically useful molecules. Here we show that expanding the number of pyruvate kinases enables metabolic adaptation, increases strain fitness and represents an excellent target for metabolic engineering of industrial specialized metabolite producing bacteria and the activation of cryptic specialized metabolites
Improving Cognitive Visual-Motor Abilities in Individuals with Down Syndrome
Down syndrome causes a reduction in cognitive abilities, with visual-motor skills being
particularly affected. In this work, we have focused on this skill in order to stimulate better learning.
The proposal relies on stimulating the cognitive visual-motor skills of individuals with Down
Syndrome (DS) using exercises with a gestural interaction platform based on the KINECT sensor
named TANGO:H, the goal being to improve them. To validate the proposal, an experimental
single-case study method was designed using two groups: a control group and an experimental
one, with similar cognitive ages. Didactic exercises were provided to the experimental group using
visual cognitive stimulation. These exercises were created on the TANGO:H Designer, a platform that
was designed for gestural interaction using the KINECT sensor. As a result, TANGO:H allows for
visual-motor cognitive stimulation through the movement of hands, arms, feet and head. The “Illinois
Test of Psycholinguistic Abilities (ITPA)” was applied to both groups as a pre-test and post-test in its
four reference sections: visual comprehension, visual-motor sequential memory, visual association,
and visual integration. Two checks were made, one using the longitudinal comparison of the
pre-test/post-test of the experimental group, and another that relied on comparing the difference of the
means of the pre-test/post-test. We also used an observational methodology for the working sessions
from the experimental group. Although the statistical results do not show significant differences
between the two groups, the results of the observations exhibited an improvement in visual-motor
cognitive skills
Diversity of HLA Class I and Class II blocks and conserved extended haplotypes in Lacandon Mayans.
Here we studied HLA blocks and haplotypes in a group of 218 Lacandon Maya Native American using a high-resolution next generation sequencing (NGS) method. We assessed the genetic diversity of HLA class I and class II in this population, and determined the most probable ancestry of Lacandon Maya HLA class I and class II haplotypes. Importantly, this Native American group showed a high degree of both HLA homozygosity and linkage disequilibrium across the HLA region and also lower class II HLA allelic diversity than most previously reported populations (including other Native American groups). Distinctive alleles present in the Lacandon population include HLA-A*24:14 and HLA-B*40:08. Furthermore, in Lacandons we observed a high frequency of haplotypes containing the allele HLA-DRB1*04:11, a relatively frequent allele in comparison with other neighboring indigenous groups. The specific demographic history of the Lacandon population including inbreeding, as well as pathogen selection, may have elevated the frequencies of a small number of HLA class II alleles and DNA blocks. To assess the possible role of different selective pressures in determining Native American HLA diversity, we evaluated the relationship between genetic diversity at HLA-A, HLA-B and HLA-DRB1 and pathogen richness for a global dataset and for Native American populations alone. In keeping with previous studies of such relationships we included distance from Africa as a covariate. After correction for multiple comparisons we did not find any significant relationship between pathogen diversity and HLA genetic diversity (as measured by polymorphism information content) in either our global dataset or the Native American subset of the dataset. We found the expected negative relationship between genetic diversity and distance from Africa in the global dataset, but no relationship between HLA genetic diversity and distance from Africa when Native American populations were considered alone
C-S-H seeding activation of Portland and Belite cements: An enlightening in situ synchrotron powder diffraction study
C-S-H seeding in Portland cements is well known from basic scientific works and field applications. Moreover, this activation approach could be beneficial for low-CO2 cements under development where a general drawback is poor mechanical strengths during the first week of hydration. However, a mechanistic understanding of the different processes taking place when seeding is still not developed. Here, we contribute to this knowledge gap by studying one commercial Portland cement and two industrial-trial belite cements. Three different admixtures are employed, viz. two types of commercial C-S-H seeding and triisopropanolamine as a typical alkanolamine. A multitechnique approach is employed including calorimetry, ultrasonic pulse velocity, thermal analysis and Rietveld analysis of laboratory X-ray powder diffraction data. Chiefly, an in situ X-ray synchrotron diffraction study has allowed mapping out the evolution of every crystalline phase. Furthermore, the use of an internal standard permitted to measure the changes in the overall amorphous content. In a nutshell, alite and belite (phases) hydrations are not significantly accelerated by C-S-H seeding for the three studied cements. Conversely, sulphate and aluminate phase dissolutions are enhanced. Faster ettringite crystallisation contributes to the observed improved mechanical properties at early ages. Moreover, a synergistic effect between C-S-H seeding and alkanolamine addition is proved. The importance of these findings for the possible acceleration of low-CO2 cement hydration is discussed.This research has been partly supported by two research grants PID2020-114650RB-I00 (from Spanish Government) and P18-RT-720 (from Junta de Andalucía, Spain), which are co-funded by ERDF. ALBA synchrotron is thanked for granting beamtime at BL04-MSPD beamline. We also thank the assistance of Dr. Oriol Vallcorba during the synchrotron experiment and thorough discussion of this work with Peter Schwesig (Master Builders Solutions). Funding for open access charge: Universidad de Malaga/CBUA
- …