490 research outputs found
La edición y el editor hoy aproximaciones a sus funciones y competencias
Esta monografía revisa las funciones editoriales y el papel del editor en el presente. También indaga en la historicidad tanto de la edición como de la figura del editor, a nivel local y global, para mostrar los grandes hitos que han marcado el acontecer del mundo de los libros y sus impactos socioculturales. En ese recorrido, se destacan problemas como la invisibilidad del editor, la profesionalización de su oficio, el impacto de las nuevas tecnologías, entre otras. El trabajo concluye observando los grandes desafíos que enfrenta el editor y las nuevas condiciones que le plantea la era digital.Comunicador (a) SocialPregrad
Functional diversity of motoneurons in the oculomotor system
Extraocular muscles contain two types of muscle fibers according to their innervation pattern: singly innervated muscle fibers (SIFs), similar to most skeletal muscle fibers, and multiply innervated muscle fibers (MIFs). Morphological studies have revealed that SIF and MIF motoneurons are segregated anatomically and receive different proportions of certain afferents, suggesting that while SIF motoneurons would participate in the whole repertoire of eye movements, MIF motoneurons would contribute only to slow eye movements and fixations. We have tested that proposal by performing single-unit recordings, in alert behaving cats, of electrophysiologically identified MIF and SIF motoneurons in the abducens nucleus. Our results show that both types of motoneuron discharge in relation to eye position and velocity, displaying a tonic–phasic firing pattern for different types of eye movement (saccades, vestibulo-ocular reflex, vergence) and gaze-holding. However, MIF motoneurons presented an overall reduced firing rate compared with SIF motoneurons, and had significantly lower recruitment threshold and also lower eye position and velocity sensitivities. Accordingly, MIF motoneurons could control mainly gaze in the off-direction, when less force is needed, whereas SIF motoneurons would contribute to increase muscle tension progressively toward the on-direction as more force is required. Anatomically, MIF and SIF motoneurons distributed intermingled within the abducens nucleus, with MIF motoneurons being smaller and having a lesser somatic synaptic coverage. Our data demonstrate the functional participation of both MIF and SIF motoneurons in fixations and slow and phasic eye movements, although their discharge properties indicate a functional segregation.Ministerio de Ciencia, Innovación y Universidades – Fondo Europeo de Desarrollo Regional (BFU2015-64515-P)Junta de Andalucía (BIO-297
Restoration enhances wetland biodiversity and ecosystem service supply, but results are context-dependent: a meta-analysis
Wetlands are valuable ecosystems because they harbor a huge biodiversity and provide key services to societies. When natural or human factors degrade wetlands, ecological restoration is often carried out to recover biodiversity and ecosystem services (ES). Although such restorations are routinely performed, we lack systematic, evidence-based assessments of their effectiveness on the recovery of biodiversity and ES. Here we performed a meta-analysis of 70 experimental studies in order to assess the effectiveness of ecological restoration and identify what factors affect it. We compared selected ecosystem performance variables between degraded and restored wetlands and between restored and natural wetlands using response ratios and random-effects categorical modeling. We assessed how context factors such as ecosystem type, main agent of degradation, restoration action, experimental design, and restoration age influenced post-restoration biodiversity and ES. Biodiversity showed excellent recovery, though the precise recovery depended strongly on the type of organisms involved. Restored wetlands showed 36% higher levels of provisioning, regulating and supporting ES than did degraded wetlands. In fact, wetlands showed levels of provisioning and cultural ES similar to those of natural wetlands; however, their levels of supporting and regulating ES were, respectively, 16% and 22% lower than in natural wetlands. Recovery of biodiversity and of ES were positively correlated, indicating a win-win restoration outcome. The extent to which restoration increased biodiversity and ES in degraded wetlands depended primarily on the main agent of degradation, restoration actions, experimental design, and ecosystem type. In contrast, the choice of specific restoration actions alone explained most differences between restored and natural wetlands. These results highlight the importance of comprehensive, multi-factorial assessment to determine the ecological status of degraded, restored and natural wetlands and thereby evaluate the effectiveness of ecological restorations. Future research on wetland restoration should also seek to identify which restoration actions work best for specific habitats
Edible coatings as a natural packaging system to improve fruit and vegetable shelf life and quality
In the past years, consumers have increased their interest in buying healthier food products, rejecting those products with more additives and giving preference to the fresh ones. Moreover, the current environmental situation has made society more aware of the importance of reducing the production of plastic and food waste. In this way and considering the food industry’s need to reduce food spoilage along the food chain, edible coatings have been considered eco-friendly food packaging that can replace traditional plastic packaging, providing an improvement in the product’s shelf life. Edible coatings are thin layers applied straight onto the food material’s surface that are made of biopolymers that usually incorporate other elements, such as nanoparticles or essential oils, to improve their physicochemical properties. These materials must provide a barrier that can prevent the passage of water vapor and other gasses, microbial growth, moisture loss, and oxidation so shelf life can be extended. The aim of this review was to compile the current data available to give a global vision of the formulation process and the different ways to improve the characteristics of the coats applied to both fruits and vegetables. In this way, the suitability of compounds in by-products produced in the food industry chain were also considered for edible coating production.Agencia Estatal de Investigación | Ref. RYC-2017-22891Xunta de Galicia | Ref. ED431F 2020/12Xunta de Galicia | Ref. ED481A2021/31
Cell immobilization of Streptomyces coelicolor : effect on differentiation and actinorhodin production
Streptomycetes are mycelium-forming bacteria that produce two thirds of the clinically relevant secondary metabolites. Despite the fact that secondary metabolite production is activated at specific developmental stages of the Streptomyces spp. life cycle, different streptomycetes show different behaviors, and fermentation conditions need to be optimized for each specific strain and secondary metabolite. Cell-encapsulation constitutes an interesting alternative to classical fermentations, which was demonstrated to be useful in Streptomyces, but development under these conditions remained unexplored. In this work, the influence of cell-encapsulation in hyphae differentiation and actinorhodin production was explored in the model Streptomyces coelicolor strain. Encapsulation led to a delay in growth and to a reduction of mycelium density and cell death. The high proportion of viable hyphae duplicated extracellular actinorhodin production in the encapsulated cultures with respect to the non-encapsulated ones. [Int Microbiol 2014; 17(2):75-80]Keywords: Streptomyces coelicolor · encapsulation · differentiation · antibiotics · cell deat
Cell immobilization of Streptomyces coelicolor : effect on differentiation and actinorhodin production
Streptomycetes are mycelium-forming bacteria that produce two thirds of the clinically relevant secondary metabolites. Despite the fact that secondary metabolite production is activated at specific developmental stages of the Streptomyces spp. life cycle, different streptomycetes show different behaviors, and fermentation conditions need to be optimized for each specific strain and secondary metabolite. Cell-encapsulation constitutes an interesting alternative to classical fermentations, which was demonstrated to be useful in Streptomyces, but development under these conditions remained unexplored. In this work, the influence of cell-encapsulation in hyphae differentiation and actinorhodin production was explored in the model Streptomyces coelicolor strain. Encapsulation led to a delay in growth and to a reduction of mycelium density and cell death. The high proportion of viable hyphae duplicated extracellular actinorhodin production in the encapsulated cultures with respect to the non-encapsulated ones. [Int Microbiol 2014; 17(2):75-80]Keywords: Streptomyces coelicolor · encapsulation · differentiation · antibiotics · cell deat
A Single Intraventricular Injection of VEGF Leads to Long-Term Neurotrophic Effects in Axotomized Motoneurons
Vascular endothelial growth factor (VEGF) has been recently demonstrated to induce neuroprotective and synaptotrophic effects on lesioned neurons. Hitherto, the administration of VEGF in different animal models of lesion or disease has been conducted following a chronic protocol of administration. We questioned whether a single dose of VEGF, administered intraventricularly, could induce long-term neurotrophic effects on injured motoneurons. For this purpose, we performed in cats the axotomy of abducens motoneurons and the injection of VEGF into the fourth ventricle in the same surgical session and investigated the discharge characteristics of axotomized and treated motoneurons by single-unit extracellular recordings in the chronic alert preparation. We found that injured motoneurons treated with a single VEGF application discharged with normal characteristics, showing neuronal eye position (EP) and velocity sensitivities similar to control, thereby preventing the axotomy-induced alterations. These effects were present for a prolonged period of time (50 d) after VEGF administration. By confocal immunofluorescence we also showed that the synaptic stripping that ensues lesion was not present, rather motoneurons showed a normal synaptic coverage. Moreover, we demonstrated that VEGF did not lead to any angiogenic response pointing to a direct action of the factor on neurons. In summary, a single dose of VEFG administered just after motoneuron axotomy is able to prevent for a long time the axotomy-induced firing and synaptic alterations without any associated vascular sprouting. We consider that these data are of great relevance due to the potentiality of VEGF as a therapeutic agent in neuronal lesions and diseases.Ministerio de Economía y Competitividad-FEDER (BFU2015-64515-P)Ministerio de Ciencia, Innovación y Universidades (PGC2018-094654- B-100
Análisis de la estructura porosa y ciclo de vida de morteros de reparación en base cemento con polímeros
Los
morteros
de
reparación
deben
ser
capaces
de
reproducir,
o
incluso
superar,
las
prestaciones
del
soporte
en
términos
de
resistencia
y
durabilidad.
Además,
los
morteros
de
reparación
deben
tener
una
adherencia
al
soporte
suficiente
para
garantizar
el
buen
comportamiento
de
la
estructura
reparada.
Se
presentan
los
resultados
de
una
campaña
experimental
llevada
a
cabo
con
dos
morteros
de
reparación
de
base
cemento,
uno
de
los
cuales
ha
sido
formulado
con
un
contenido
de
polímero
de
un
3,2%
de
la
masa
total.
Los
morteros
han
sido
evaluados
conforme
a
los
estándares
de
la
norma
europea
UNE-EN
1504
para
morteros
estructurales
R4;
además,
se
ha
estudiado
el
comportamiento
de
ambos
morteros
en
estado
fresco
y
su
estructura
porosa
y
microestructura
mediante
porosimetría
por
intrusión
de
mercurio;
adicionalmente,
se
han
realizado
ensayos
de
propiedades
durables.
Los
resultados
obtenidos
indican
un
refinamiento
de
poros
en
el
mortero
con
polímeros,
mejorando
sus
prestaciones.
Por
último,
se
incluye
un
análisis
comparativo
del
ciclo
de
vida
de
ambos
morteros
en
dos
ambientes
con
distinto
nivel
de
agresividad,
con
objeto
de
evaluar
la
sostenibilidad
y
la
repercusión
a
lo
largo
de
la
vida
útil
de
la
incorporación
de
polímero
a
los
morteros
de
reparación
Aprendizaje Interactivo de un ERP de Código Abierto
El software empresarial ERP es un sistema de planificación de recursos y de gestión de la información. Este tipo de software suele ser complejo, de coste elevado y difícil de implantar.Para solucionar estos problemas el ERP de código abierto (OSS), frente al software propietario, puede ser utilizado, copiado, modificado y distribuido. En este trabajo, aprovechando las ventajas del código abierto, realizamos un estudio sobre la difusión, aprendizaje y utilización de un OSS por 460 alumnos de tercer curso de la Diplomatura de Empresariales (Universidad de Sevilla). Los resultados obtenidos demuestran una autonomía en el proceso de aprendizaje y una elevada utilización del material y colaboracionismo. Entre las principales mejoras para el desarrollo de futuras experiencias encontramos la necesidad anticiparse a los problemas técnicos así como el fomento de las consultas en el despacho del profesor.The ERP software is a resource planning and information management system. This kind of software is usually complex, expensive and difficult to implement. In order to solve these problems The Open Source Software (OSS) as opposed to propietary software can be used, copied, modified and even distributed. Due to the advantages the Open Source Software, in
this paper we made a study on the diffusion, learning and use of a OSS by 460 students of third course of the Degree on Business Studies (University of Seville). The results confirm an autonomy in the learning process, a high use of the material and a high collaboration of the students. The main improvements for the development of future research include to anticipate
to technical problems and the promotion of the office hours
Microstructural, chemical, and mechanical characterization of extruded Al-Cu-Li rods
This work investigates the influence of the alloying elements in rods of the alloys Al-Cu-Li produced by novel powder metallurgy routes. In the first route, the powders were mixed and uniaxial cold-pressed, followed by hot extrusion to produce 5 mm diameter rods. The second route introduced an intermediate step of heat treatment that was carried out at 525 ºC for 1 h in a pure N2 atmosphere before the extrusion. This was done to evaluate the importance of homogenization of the alloying elements during the heat treatment, as well as the tendency to form new phases in the extruded rods. The obtained rods were characterized by SEM, EBSD, Vickers micro-hardness, chemical composition (ICP-OES), and tensile tests. The results obtained showed that the alloy 1 (AA2060) presents a more homogeneous microstructure than alloy 2 (AA2196), and it is observed the benefit of Mg addition, which improves the microstructure after HT. The EBSD analysis showed a typical preferential orientation of a duplex fiber texture. The ICP-OES analysis reports losses of Li and Mg for both alloys. Regarding to the measurement of hardness, the results were very different depending on the alloy and the HT prior to the extrusion process.Paula Rodriguez Gonzalez reports financial support was provided by the Regional Government of Madrid through the project ADITIMAT-CM (Ref. S2018/NMT-4411) and by the Universidad Carlos III de Madrid (Read & Publish Agreement CRUE-CSIC 2023)
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