1,311 research outputs found
Who changes the course of history? Historical agency in the narratives of Spanish pre-service primary teachers
Brief narratives created by pre-service teachers on a primary education degree course at the University of Murcia (Spain) were analysed to identify the ways in
which they presented historical agents in European and Spanish history. The main units of analysis were categorized by the type of agent introduced in each
narrative (individual, collective and institutional), then by identifying agents as either active or passive, and finally by describing the characteristics of their actions in terms of reasons and causes/consequences. The results reveal an emphasis on individual agents and the persistence of a superficial historical master narrative
that perpetuates a distorted image of history
Clinal variation of dormancy progression in apricot
AbstractThe aim of this study was to determine the bud dormancy progression in apricot at different latitudes and altitudes. Six locations in regions with a Mediterranean climate in South Africa (SA) and Spain were chosen. The study was carried out during two consecutive years, 2007 and 2008, in SA and results were compared to those obtained in Spain in 2008. Locations ranged from low-chill areas, such as Ladismith and Villiersdorp in SA and Campotéjar in Spain, to high-chill areas, such as Ceres in SA and Barranda in Spain. A number of apricot cultivars comprising the range of chilling requirements in both countries were selected. In addition, a second, parallel study was performed to evaluate the paradormancy progression in ‘Palsteyn’ (SA) and ‘Rojo Pasión’ (Spain). Deeper dormancy was not observed in high-chill cultivars located in cold areas than in low-chill cultivars in warm areas. However, low-chill cultivars located in warm areas entered and released from dormancy earlier than high chill cultivars in warm areas. Thus, a clinal variation in dormancy progression under warm temperatures in apricot cultivars is suggested. The role of photoperiod and minimum temperatures is proposed to have a key role in dormancy onset. Paradoxically, an earlier maximum depth of dormancy was found in those areas with higher minimum temperatures at the end of summer. Before the beginning of winter, all cultivars showed an important increase of budburst rate, which indicated the end of endodormancy. Afterwards an ecodormancy period followed during winter, while chilling continued to accumulate. These results contrast with the assumed concept of the breaking of dormancy through chilling accumulation during winter and suggest a possible mediation by photoperiod in overcoming of dormancy. On the other hand, paradormancy exerted a reduction in budburst rate during dormancy entry, whereas decapitation increased the budburst rate throughout the dormant season, indicating interaction between different plant parts during this period
Plasma cytokines as potential biomarkers of kidney damage in patients with systemic lupus erythematosus
Background: Systemic lupus erythematosus is a heterogeneous chronic inflammatory autoimmune
disorder characterized by an exacerbated expression of cytokines and chemokines in
different tissues and organs. Renal involvement is a significant contributor to the morbidity
and mortality of systemic lupus erythematosus, and its diagnosis is based on renal biopsy,
an invasive procedure with a high risk of complications. Therefore, the development of
alternative, non-invasive diagnostic tests for kidney disease in patients with systemic lupus
erythematosus is a priority. Aim: To evaluate the plasma levels of a panel of cytokines and
chemokines using multiplex xMAP technology in a cohort of Colombian patients with active
and inactive systemic lupus erythematosus, and to evaluate their potential as biomarkers of
renal involvement. Results: Plasma from 40 systemic lupus erythematosus non-nephritis
patients and 80 lupus nephritis patients with different levels of renal involvement were analyzed
for 39 cytokines using Luminex xMAP technology. Lupus nephritis patients had significantly
increased plasma eotaxin, TNF-a, interleukin-17-a, interleukin-10, and interleukin-15
as compared to the systemic lupus erythematosus non-nephritis group. Macrophage-derived
chemokine, growth regulated oncogene alpha, and epidermal growth factor were significantly
elevated in systemic lupus erythematosus non-nephritis patients when compared to lupus
nephritis individuals. Plasma eotaxin levels allowed a discrimination between systemic lupus
erythematosus non-nephritis and lupus nephritis patients, for which we performed a receiver
operating characteristic curve to confirm. We observed a correlation of eotaxin levels with
active nephritis (Systemic Lupus Erythematosus Disease Activity Index). Our data indicate
that circulating cytokines and chemokines could be considered good predictors of renal
involvement in individuals with systemic lupus erythematosus
The Influence of the Coach’s Autonomy Support and Controlling Behaviours on Motivation and Sport Commitment of Youth Soccer Players
The coach is one of the most influential agents in the sport commitment of youth players. Grounded in self-determination theory (SDT), numerous studies have examined the influence of the coach’s autonomy-supportive behaviours on athletes’ motivation. However, fewer studies have examined the influence of the coach’s controlling behaviours. The aim of this cross-sectional study was to analyse the influence of young soccer players’ perception of their coach’s autonomy-supportive and controlling behaviours on the satisfaction and frustration of their basic psychological needs (BPN) and sport commitment. A total of 203 soccer players (86% boys), aged 10–19 years (M = 14.88; SD = 1.54) participated. Coach autonomy support positively predicted BPN satisfaction which, in turn, positively explained sport commitment. Coach intimidation behaviours positively predicted BPN frustration, which, in turn, negatively explained sport commitment. In cross-relationships, autonomy support negatively explained BPN frustration, while intimidation behaviours and the controlling use of rewards negatively predicted BPN satisfaction. To conclude, these results suggest that it is important for the coach not only to support autonomy, but also to avoid the use of controlling behaviours, especially intimidation and controlling use of rewards, because of their influence on the motivational processes and sport commitment of youth soccer players
Desarrollo sustentable y cambio global
En agosto de 2004 falleció Víctor L. Urquidi, uno de los intelectuales más destacados y originales de México y de América Latina en nuestro tiempo. Su obra académica, escrita a lo largo de más de sesenta años, es de enorme trascendencia. Víctor L. Urquidi fue también un gran constructor de instituciones e impulsor de importantes proyectos nacionales e internacionales. Como funcionario del Banco de México, de la Secretaría de Hacienda y Crédito Público y de Naciones Unidas en los decenios de 1940 y 1950, contribuyó al desarrollo del país y a notables iniciativas de integración regional. Fue presidente de El Colegio de México de 1966 a 1985, donde promovió infatigablemente las humanidades y ciencias sociales en sus vertientes más sólidas y novedosas. Sus intereses alcanzaron un vasto paisaje académico y se encuentran resumidos en una obra escrita que por extensa y diversa no está fácilmente al alcance del público lector. El Colegio de México —casa de Víctor L. Urquidi— ha considerado de suma importancia rendir homenaje al maestro, mediante la publicación de una selección de sus textos ordenados temáticamente a lo largo de varios volúmenes de esta colección de sus Obras escogidas, prologados y seleccionados por especialistas en la materia. Este libro editado por Alejandro Nadal es un buen ejemplo. Víctor L. Urquidi trabajó sobre temas fundamentales, como economía y desarrollo, política demográfica, integración regional y ciencia y tecnología
Assessment of Muscle Coordination Changes Caused by the Use of an Occupational Passive Lumbar Exoskeleton in Laboratory Conditions
[EN] The introduction of exoskeletons in industry has focused on improving worker safety. Exoskeletons have the objective of decreasing the risk of injury or fatigue when performing physically demanding tasks. Exoskeletons' effect on the muscles is one of the most common focuses of their assessment. The present study aimed to analyze the muscle interactions generated during load-handling tasks in laboratory conditions with and without a passive lumbar exoskeleton. The electromyographic data of the muscles involved in the task were recorded from twelve participants performing load-handling tasks. The correlation coefficient, coherence coefficient, mutual information, and multivariate sample entropy were calculated to determine if there were significant differences in muscle interactions between the two test conditions. The results showed that muscle coordination was affected by the use of the exoskeleton. In some cases, the exoskeleton prevented changes in muscle coordination throughout the execution of the task, suggesting a more stable strategy. Additionally, according to the directed Granger causality, a trend of increasing bottom-up activation was found throughout the task when the participant was not using the exoskeleton. Among the different variables analyzed for coordination, the most sensitive to changes was the multivariate sample entropy.This study was funded by Fundación Prevent.Iranzo-Egea, S.; Belda-Lois, J.; Martínez-De-Juan, JL.; Prats-Boluda, G. (2023). Assessment of Muscle Coordination Changes Caused by the Use of an Occupational Passive Lumbar Exoskeleton in Laboratory Conditions. Sensors. 23(24):1-14. https://doi.org/10.3390/s23249631114232
Patología implanto-endodóncica: concepto, tipos, diagnóstico, tratamiento y prevención.
La patología implanto-endodóncica (PIE) está descrita en la literatura implantológica como una de
las causas de periimplantitis apical, entendida como la lesión osteolítica en la región apical del
implante, con normal osteointegración de su porción coronal, provocada por la infección por contigüidad
a partir de la lesión periapical del diente adyacente. Pero el concepto de PIE no sólo
abarca la periimplantitis retrógrada por contaminación diente-a-implante, sino también los procesos
inflamatorios periapicales en dientes adyacentes al implante por contaminación implante-adiente,
cuando la colocación del implante provoca la necrosis del diente adyacente y la consiguiente
periodontitis apical. Incluso podríamos incluir dentro de la PIE los casos de periimplantitis
apical en implantes postextracción provocada por la infección residual presente en el alvéolo de
un diente extraído con periodontitis apical. En definitiva, la PIE incluye las lesiones endodóncicas e
implantarias apicales que son el resultado de infecciones residuales o por contigüidad entre diente
e implante. En esta revisión bibliográfica se define y clasifica la PIE, repasándose la casuística
publicada así como su influencia en el resultado del tratamiento implantológico
Direct visualization reveals dynamics of a transient intermediate during protein assembly
Interactions between proteins underlie numerous biological functions. Theoretical work suggests that protein interactions initiate with formation of transient intermediates that subsequently relax to specific, stable complexes. However, the nature and roles of these transient intermediates have remained elusive. Here, we characterized the global structure, dynamics, and stability of a transient, on-pathway intermediate during complex assembly between the Signal Recognition Particle (SRP) and its receptor. We show that this intermediate has overlapping but distinct interaction interfaces from that of the final complex, and it is stabilized by long-range electrostatic interactions. A wide distribution of conformations is explored by the intermediate; this distribution becomes more restricted in the final complex and is further regulated by the cargo of SRP. These results suggest a funnel-shaped energy landscape for protein interactions, and they provide a framework for understanding the role of transient intermediates in protein assembly and biological regulation
Reclassification of Geobacillus pallidus (Scholz et al. 1988) Banat et al. 2004 as Aeribacillus pallidus gen. nov., comb., nov.
Although Anoxybacillus and Geobacillus, two genera of thermophilic bacteria close to the genus Bacillus, have only been described recently, the number of species in these genera has increased rapidly. Four thermophilic, lipolytic strains (DR01, DR02, DR03 and DR04) isolated from a hot spring in Veracruz (Mexico), which could not be identified phenotypically, were subjected to 16S rRNA gene sequence analysis. Three strains were identified as belonging to the genus Anoxybacillus, but strain DR03 was identified as Geobacillus pallidus. This result led us to perform a phylogenetic analysis of the genera Anoxybacillus and Geobacillus based on 16S rRNA gene sequences from all the type strains of these genera. Phylogenetic trees showed three major clusters, Anoxybacillus-Geobacillus tepidamans, Geobacillus sensu stricto and Geobacillus pallidus, while the 16S rRNA gene sequences of G. pallidus (DR03 and the type strain) showed low similarity to sequences of Anoxybacillus (92.5-95.1 %) and Geobacillus (92.8-94.5 %) species, as well as to Bacillus subtilis (92.2-92.4 %). In addition, G. pallidus could be differentiated from Anoxybacillus and Geobacillus on the basis of DNA G+C content and fatty acid and polar lipid profiles. From these results, it is proposed that Geobacillus pallidus should be classified in a novel genus, for which we propose the name Aeribacillus, as Aeribacillus pallidus gen. nov., comb. nov. The type strain of Aeribacillus pallidus is H12T (=ATCC 51176T =DSM 3670T =LMG 19006T)
Recovering Tomato Landraces to Simultaneously Improve Fruit Yield and Nutritional Quality Against Salt Stress
Salt stress generally induces important negative effects on tomato (Solanum lycopersicum) productivity but it may also cause a positive effect improving fruit quality, one of the greatest challenges in nowadays agriculture. Because of the genetic erosion of this horticultural species, the recovery of locally adapted landraces could play a very important role in avoiding, at least partially, production losses and simultaneously improving fruit quality. Two tomato landraces endemic of the Spanish Southeast area, characterized by the harsh climatic conditions of the Mediterranean basin, have been selected: Negro Yeste (NY) characterized by its dark-red colored fruits and Verdal (V), which fruits did not achieve the characteristic red color at ripening. Here the agronomic, physiological, and metabolic responses of these landraces were compared with the reference tomato commercial cv. Moneymaker (MM), in plants grown without salt (control) and with salt stress (100 mM NaCl) for 70 days. The higher salt tolerance of both landraces was mainly reflected in the fruit number, as NY only reduced the fruit number in salt stress by 20% whereas in MM it was reduced till 43%, and in V the fruit number even showed an increase of 33% with salt stress. An important fruit quality parameter is soluble solids content, which increases induced by salinity were significantly higher in both landraces (60 and 78% in NY and V, respectively) compared with MM (34%). Although both landraces showed a similar response in relation to the high chlorophyll accumulation detected in their fruits, the fruit metabolic profiles were very different. Increased carotenoids levels were found in NY fruits, especially lycopene in ripe fruit, and this characteristic was observed in both control and salt stress. Contrarily, the carotenoid biosynthesis pathway was disrupted in V ripe fruits, but other metabolites, such as Ca2+, mannose, formate, and glutamate were accumulated. These results highlight the potential of tomato landraces to improve nutritional fruit quality and maintain fruit yield stability under salt stress
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