2,595 research outputs found

    Mindfulness and job control as moderators of the relationships between demands and innovative work behaviours

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    Innovation enables organizations to respond successfully to rapid changes in a business environment. This innovation capability largely relies on employees. Although workers are required to be innovative, their jobs frequently contain higher demands that might make it difficult for them to innovate at work. The Job Demands-Control model active hypothesis suggests that highly demanding jobs that allow individuals enough discretion enhance innovative performance. Improving an important attentional resource such as mindfulness at work might also play a similar role, although there is a need for more research at this level. The main aim of this study is to examine the relative contribution of job control and increases in mindfulness as moderators in the job demands-innovation work behaviours relationship. The results obtained with 221 workers indicated that in previous situations characterized by high job demands (T1), workers who increase their capacity for mindfulness are more innovative in the future (T2)

    An overview on the Prus-Szczepanik condition

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    In 2005 Prus and Sczcepanik introduced a large class of Banach spaces with the fixed point property for nonexpansive mappings. We say that this class satisfies the PSz condition. Checking that a given Banach space belongs to this class is not an easy task. Here we study the relationship between the PSz condition and other well-known geometrical properties of Banach spaces, and we give easier sufficient conditions for a Banach space to satisfy it.Consejo Nacional de Ciencia y Tecnologia (México)Ministerio de Economía y Competitivida

    Electrical properties of individual tin oxide nanowires contacted to platinum electrodes

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    A simple and useful experimental alternative to field-effect transistors for measuring electrical properties free electron concentration nd, electrical mobility , and conductivity in individual nanowires has been developed. A combined model involving thermionic emission and tunneling through interface states is proposed to describe the electrical conduction through the platinum-nanowire contacts, fabricated by focused ion beam techniques. Current-voltage I-V plots of single nanowires measured in both two- and four-probe configurations revealed high contact resistances and rectifying characteristics. The observed electrical behavior was modeled using an equivalent circuit constituted by a resistance placed between two back-to-back Schottky barriers, arising from the metal-semiconductor-metal M-S-M junctions. Temperature-dependent I-V measurements revealed effective Schottky barrier heights up to BE= 0.4 eV

    Phytochemical evaluation of white (Morus alba L.) and black (Morus nigra L.) mulberry fruits, a starting point for the assessment of their beneficial properties

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    Abstract This study evaluated, for the first time, the phenolic content of white ( Morus alba ) and black mulberry ( Morus nigra ) fruits with proven market aptitudes and grown in Spain, one of the main European producers. The antioxidant activity and mineral composition of these promising berry fruits were also assessed. Black mulberry clones showed higher antioxidant activity and amounts of phenolic compounds than white mulberry clones, although a wide intra-species variability was noted, according to principal component analysis. The total anthocyanins varied significantly among clones of M. nigra . These results are keys for the design of future dietary intervention studies examining the role of mulberry fruits in disease risk reduction. They can also be used for the development of mulberry derived-products rich in phenolic compounds

    (Poly)phenolic compounds and antioxidant activity of white (Morus alba) and black (Morus nigra) mulberry leaves: Their potential for new products rich in phytochemicals

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    Abstract The (poly)phenolic fingerprint and antioxidant activities of the leaves of white and black mulberry clones grown in Spain, one of the main European producers, were evaluated for the first time in order to examine their phytochemical potential. Data showed that mulberry leaves are rich in caffeoylquinic acids (6.8–8.5 mg/g dw) and flavonols (3.7–9.8 mg/g dw). It was also evidenced that a wide intra-species variability existed according to principal component analysis. These results can be useful for value-added utilisation of this underused vegetal matrix by the food/pharma industries. In addition, owing to their (poly)phenolic composition with proven biological activities, these data can serve as starting point for further nutritional studies with mulberry leaf-derived products

    Deep ocean prokaryotes and fluorescent dissolved organic matter reflect the history of the water masses across the Atlantic Ocean

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    Organic matter is known to influence community composition and metabolism of marine prokaryotes. However, few studies have addressed this linkage in the deep ocean. We studied the relationship between fluorescent dissolved organic matter and prokaryotic community composition in meso- and bathypelagic water masses along a surface productivity gradient crossing the subtropical and tropical Atlantic Ocean. Four fluorescence components were identified, three humic-like and one protein-like. The distributions of the humic-like components were significantly explained by water mass mixing, apparent oxygen utilisation (AOU) and epipelagic productivity proxies in varying degrees, while the protein-like component was explained only by water mass mixing and epipelagic productivity. The diversity and taxonomic composition of the prokaryotic community differed between water masses: the Nitrosopumilales order dominated in water masses with high AOU and humic-like fluorescence (notably, the SubPolar Mode Water), and tended to co-occur with Marine Group II archaea, the SAR324 clade and Thiomicrospirales, while bathypelagic water masses displayed greater abundances of members of Marinimicrobia, SAR202 and SAR324. Water mass mixing regression models suggested that the distribution of some taxa (e.g., Marinimicrobia, SAR202) was dominated by mixing and selection within the water masses during ageing, while others (chiefly, Alteromonadales) were mostly influenced by local processes. Our results suggest a link between the composition of the prokaryotic community, oxygen utilisation and the signal of fluorescent dissolved organic matter, and has implications for our understanding of the processes that shape carbon cycling and prokaryotic communities in the deep ocean.3,26

    Unraveling the origin of magnetism in mesoporous Cu-doped SnO₂ magnetic semiconductor

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    The origin of magnetism in wide-gap semiconductors doped with non-ferromagnetic 3d transition metals still remains intriguing. In this article, insights in the magnetic properties of ordered mesoporous Cu-doped SnO₂ powders, prepared by hard-templating, have been unraveled. Whereas, both oxygen vacancies and Fe-based impurity phases could be a plausible explanation for the observed room temperature ferromagnetism, the low temperature magnetism is mainly and unambiguously arising from the nanoscale nature of the formed antiferromagnetic CuO, which results in a net magnetization that is reminiscent of ferromagnetic behavior. This is ascribed to uncompensated spins and shape-mediated spin canting effects. The reduced blocking temperature, which resides between 30 and 5 K, and traces of vertical shifts in the hysteresis loops confirm size effects in CuO. The mesoporous nature of the system with a large surface-to-volume ratio likely promotes the occurrence of uncompensated spins, spin canting, and spin frustration, offering new prospects in the use of magnetic semiconductors for energy-efficient spintronics

    Periodic lateralized epileptiform discharges as manifestation of pneumococcal meningoencephalitis

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    Periodic Lateralized Epileptiform Discharges (PLEDs) are usually seen in the context of destructive structural lesions of the cortex, more frequently in acute ischemic stroke and less common in tumours and meningoencephalitis, specially herpes simplex virus. Its origin and prognosis are uncertain but it is known that PLEDs are linked to epilectic seizures, including status epilepticus

    Forest decline evaluation in Antarctic Beech Forests (Nothofagus antarctica) in Chilean Patagonia by using Landsat TM and ETM+

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    Antarctic beech forests (Nothofagus antarctica (G. Forst.) Oerst.) have shown a major decline process in the past few decades, together with an important lack of specific studies on this type of forest. The aim of this work was to create cartography of the surface of Antarctic beech forests and to evaluate decline levels in the XII Region of Chile. A study area was selected between the cities of Puerto Natales and Punta Arenas (latitudes 50º40’S to 52º40’S) and from latitudes 60º15’W to 74º15’W, where a random stratified sampling was carried out in 68 plots, in which the forest cover, mortality, height, normal diameter and regeneration were measured. Using two Landsat images (1986-2002), the study area was classified in terms of vegetation cover and forest mortality, by means of the normalized vegetation index (NDVI). The forests in this study area are characterized by their high density, and, in over half their surface (27,873 ha) they exhibit some degree of mortality, with 7,585 ha of forest completely affected. The distribution of the mortality in Antarctic beech on the period 1986-2002 showed an improvement on forests condition, which seems to corroborate the hypothesis of a change on perturbation pattern as the major reason for this forest decline process.Los bosques de ñirre (Nothofagus antarctica) han experimentado en las últimas décadas un importante proceso de mortalidad. El objetivo de este trabajo fue elaborar una cartografía de las masas de ñirre en función de la fracción de cabida cubierta del dosel arbóreo y el nivel de mortalidad en la XII Región de Chile. En una zona entre las ciudades de Puerto Natales y Punta Arenas (50º40’ - 52º40’ S y 69º15’ - 74º15’ O) se realizó un muestreo estratificado en 68 parcelas, donde se midieron: fracción de cabida cubierta, mortandad del arbolado, altura, diámetro normal (DAP) y regeneración. Mediante clasificación de dos imágenes Landsat TM (1986) y ETM+ (2002) se estudiaron el estado de las masas de ñirre y la evolución de la mortandad en un periodo de 16 años, utilizando el índice de vegetación normalizado (NDVI). En el año 2002 los bosques de ñirre se caracterizaban por una elevada fracción de cabida cubierta, tallas y diámetros medios, y una escasa regeneración. Más de la mitad de la superficie de estudio (casi 28.000 ha) presentaba algún grado de mortandad del arbolado, con 7.585 ha de bosques totalmente muertos. El patrón de mortandad, por comparación con el estado del arbolado en 1986, indicó una tendencia a mejorar el estado del arbolado en los últimos 16 años, lo cual parece confirmar la hipótesis de que los procesos de mortandad en esta especie no están asociados a un cambio en el patrón climático en la zona, sino más bien a la modificación del régimen de perturbaciones

    Non-Excitatory Amino Acids, Melatonin, and Free Radicals: Examining the Role in Stroke and Aging

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    The aim of this review is to explore the relationship between melatonin, free radicals, and non-excitatory amino acids, and their role in stroke and aging. Melatonin has garnered significant attention in recent years due to its diverse physiological functions and potential therapeutic benefits by reducing oxidative stress, inflammation, and apoptosis. Melatonin has been found to mitigate ischemic brain damage caused by stroke. By scavenging free radicals and reducing oxidative damage, melatonin may help slow down the aging process and protect against age-related cognitive decline. Additionally, non-excitatory amino acids have been shown to possess neuroprotective properties, including antioxidant and anti-inflammatory in stroke and aging-related conditions. They can attenuate oxidative stress, modulate calcium homeostasis, and inhibit apoptosis, thereby safeguarding neurons against damage induced by stroke and aging processes. The intracellular accumulation of certain non-excitatory amino acids could promote harmful effects during hypoxia-ischemia episodes and thus, the blockade of the amino acid transporters involved in the process could be an alternative therapeutic strategy to reduce ischemic damage. On the other hand, the accumulation of free radicals, specifically mitochondrial reactive oxygen and nitrogen species, accelerates cellular senescence and contributes to age-related decline. Recent research suggests a complex interplay between melatonin, free radicals, and non-excitatory amino acids in stroke and aging. The neuroprotective actions of melatonin and non-excitatory amino acids converge on multiple pathways, including the regulation of calcium homeostasis, modulation of apoptosis, and reduction of inflammation. These mechanisms collectively contribute to the preservation of neuronal integrity and functions, making them promising targets for therapeutic interventions in stroke and age-related disorders.This work was supported by MICIU (grant number PID2021-128133NB-I00/AEI/FEDER10.13039/501100011033) to J.M.H.-G. and V.J.C. enjoys a contract from the CAM “Investigo” program (PIP/2022-09971). A.R. thanks UCJC (INFLAMAMEL 2022-07 project) for its continued support
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