Search results for "1105"
showing 10 items of 459 documents
The power of empowering team leadership over time: A multi-wave longitudinal study in nuclear power plants
2021
Abstract Team attitudes in critical infrastructures are essential to achieving reliable operations despite internal and external challenges, and empowering team leadership (ETL) may be an important precursor of these attitudes. The present study aimed to test whether ETL was related to teams’ satisfaction trajectories, measured as changes in job satisfaction and safety satisfaction at three time points. Hypotheses were tested in a sample of 48 teams from two Spanish nuclear facilities in three different waves (2008, 2011, and 2014). Growth Modeling using hierarchical linear models with SPSS 20.0 revealed that ETL was positively related to initial levels of teams’ job and safety satisfaction…
Toward a wiser projectification: Macroeconomic effects of firm-level project work
2019
Abstract Several studies have investigated projectification and its effects at the firm level, but the macroeconomic implications of project work have scarcely been considered. This paper analyzes the macroeconomic effects of firm-level projectification. We study the interlinkages between different sectors by extending standard input-output modeling and analyze the static and dynamic effects of projectification. The results indicate that projectification can have positive macroeconomic implications for production/innovativeness, employment and income that differ across economic sectors, but projectification can also have negative impacts. As a major implication, the use of temporary forms o…
Daphnia females adjust sex allocation in response to current sex ratio and density
2018
Cyclical parthenogenesis presents an interesting challenge for the study of sex allocation, as individuals’ allocation decisions involve both the choice between sexual and asexual reproduction, and the choice between sons and daughters. Male production is therefore expected to depend on ecological and evolutionary drivers of overall investment in sex, and those influencing male reproductive value during sexual periods. We manipulated experimental populations, and made repeated observations of natural populations over their growing season, to disentangle effects of population density and the timing of sex from effects of adult sex ratio on sex allocation in cyclically parthenogenetic Daphnia…
Sperm competition in yellow dung flies: No consistent effect of sperm size
2022
The male competition for fertilization that results from female multiple mating promotes the evolution of increased sperm numbers and can impact sperm morphology, with theory predicting that longer sperm can at times be advantageous during sperm competition. If so, males with longer sperm should sire more offspring than competitors with shorter sperm. Few studies have directly tested this prediction, and findings are inconsistent. Here we assessed whether longer sperm provide a competitive advantage in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae). Initially, we let brothers with different temperature-mediated mean sperm lengths compete - thus minimizing confounding…
Assessing Reliability, Heritability and General Cognitive Ability in a Battery of Cognitive Tasks for Laboratory Mice
2005
This report includes the first sibling study of mouse behavior, and presents evidence for a heritable general cognitive ability (g) factor influencing cognitive batteries. Data from a population of male and female outbred mice (n = 84), and a replication study of male sibling pairs (n = 167) are reported. Arenas employed were the T-maze, the Morris water maze, the puzzle box, the Hebb-Williams maze, object exploration, a water plus-maze, and a second food-puzzle arena. The results show a factor structure consistent with the presence of g in mice. Employing one score per arena, this factor accounts for 41% of the variance in the first study (or 36% after sex regression) and 23% in the second…
Androglobin: a chimeric globin in metazoans that is preferentially expressed in mammalian testes
2012
Abstract: Comparative genomic studies have led to the recent identification of several novel globin types in the Metazoa. They have revealed a surprising evolutionary diversity of functions beyond the familiar O2 supply roles of hemoglobin and myoglobin. Here we report the discovery of a hitherto unrecognized family of proteins with a unique modular architecture, possessing an N-terminal calpain-like domain, an internal, circular permuted globin domain, and an IQ calmodulin-binding motif. Putative orthologs are present in the genomes of many metazoan taxa, including vertebrates. The calpain-like region is homologous to the catalytic domain II of the large subunit of human calpain-7. The glo…
The effect of prolonged storage time on asphalt rubber binder properties
2019
Abstract This study wants to provide fundamental understanding of prolonged storage time on asphalt rubber binder properties by performing an investigation on the variation of conventional properties, rheology and morphology of four asphalt rubbers maintained at 180 °C in low shear for different digestion/storage times up to 48 h. The analysed asphalt rubbers were manufactured by combining two different asphalt binder grades, pen 35/50 and pen 50/70, with both cryogenic and ambient crumb rubber. Results have shown that keeping asphalt rubber agitated at the above mentioned processing conditions, up to 48 h, is significantly detrimental when an ambient crumb rubber is used, while it seems no…
The effects of laboratory ageing on rheological and fracture characteristics of different rubberised bitumens
2018
Ageing of bituminous materials can result in loss of the durability of a flexible pavement. Using rubberised bitumens can enhance pavement performance while at the same time it solves a serious waste disposal problem. Combining Warm Mix Asphalt (WMA) additives with rubberised bitumens reduces the difficulties associated with the production of asphalt mixtures using this modified binder. This work was conducted to study the effect of ageing using fundamental parameters based on performance, i.e., CTOD and Glover-Rowe parameters have been related to pavement cracking. Different unmodified bitumens and rubberised bitumens were short-term aged using the Thin Film Oven Test (TFOT) and long- term…
A simple model for the calculation of the axial load-carrying capacity of corroded RC columns
2015
In the present paper, a simplified model is used to determine the axial load-carrying capacity of compressed short reinforced concrete columns subjected to corrosion processes. The model considers members with circular and square cross-sections and accounts for—cover spalling, —concrete core confinement induced by transverse steel reinforcement, —buckling of longitudinal reinforcing bars. Strength reduction in concrete cover and core due to cracking induced by rust formation, reduction of steel area in longitudinal bars and transverse stirrups due to general and pitting corrosion and loss of confinement pressure are considered. The load-carrying capacity and load-axial strain curves here ge…
Shear and flexural strength prediction of corroded R.C. beams
2017
Abstract The purpose of the work was the study of the structural safety of R.C. beams subjected to corrosion processes though the derivation of moment-curvature diagrams and moment-to-shear interaction diagrams. Normal-strength reinforced concrete beams with longitudinal bars in the presence of transverse stirrups and subjected to corrosion processed are considered. Experimental results available in the literature related to corrosion processes, for steel bars, crack openings and bond degradation due to rust formation are reviewed. Then analytical laws relating to crack opening, bond degradation with attack penetration depth, through a rearranged form of Faraday’s law, are presented. An ana…