996 resultados para minor planets, asteroids: individual (Euphrosyne)
Resumo:
Previous research on Human Resource Management (HRM) has focused extensively on the potential relationships between the use of HRM practices and organizational performance. Extant research in HRM has been based on the underlying assumption that HRM practices can enhance organizational performance through their impact on positive employee attitudes and performance, that is, employee reactions to HRM. At the current state of research however, it remains unclear how employees come to perceive and react to HRM practices and to what extent employees in organizations, units and teams react to such practices in similar or widely different ways. In fact, recent HRM studies indicate that employee reactions to HRM may be far less homogeneous than assumed. This raises the question of whether or not the linkage between HRM and organizational outcomes can be explained by employee reactions in terms of attitudes and performance, if these reactions are largely idiosyncratic. Accordingly, this thesis aims to shed light on the processes that shape individuals’ reactions to HRM practices and how these processes may influence the variance or sharedness in such reactions among employees in organizations, units and teams. By theoretically developing and empirically examining the effects of employee perceptions of HRM practices from the perspective of ‘HRM as signaling’ and psychological contract theory, the main contributions of this thesis focus on the following research questions: i) How employee perceptions of the HRM practices relate to individual and collective employee attitudes and performance. ii) How employee perceptions of HRM practices relates to variance in employee attitudes and performance. iii) How collective employee performance mediates the relationship between employee perceptions of HRM practices and organizational performance. Regarding the first research questions the findings indicate that individuals do respond positively to HRM practices by adjusting their felt obligations towards the employer. This finding is in line with the idea of HRM as a signaling device where each HRM practice, implicitly or explicitly, sends signals to employees about promised rewards (inducements) and behaviors (obligations) expected in return. The relationship was also confirmed at the group level of analysis. What is more, variance was found to play an important role in that employee groups with more similar perceptions about the HRM system displayed a stronger relationship between HRM and employee obligations. Concerning the second question the findings were somewhat contradictory in that a strong HRM system was found negatively related to variance in employee performance but not employee obligations. Regarding the third question, the findings confirmed linkages between the HRM system and organizational performance at the group level and the HRM system and employee performance at the individual level. Also, the entire chain of links from the HRM system through variance in employee performance, and further through the level of employee performance to organizational performance was significant.
Resumo:
Adult male Nilgiri langurs (Presbytis johnii) utter loud call bouts consisting of one or more phrases. Phrases are made up of several units showing similar or different structural features. The units involved differ with respect to not only their physical structure but also their overall utilization: three vocal patterns are uttered exclusively by mature males living in bisexual groups or all-male bands and, in addition to being part of loud call bouts, are given during encounters with terrestrial predators; two vocal patterns are uttered by males and females, again not just as constituents of loud calls; and one vocal pattern is given exclusively by mature males living in bisexual groups. Within a given bout, phrases differ not only with respect to their composition but also in their temporal organization. In addition to the acoustic components, loud calls are regularly accompanied by stereotyped motoric displays. The motoric and acoustic components of loud call displays appear independently of each other and at different times during ontogeny. The development of the display is characterized by combination of units with different structural features and synchronization of vocal and motoric components. Although more evidence is needed, our observations suggest that the development of loud call displays coincides with the aquisitation of social maturation and competence and requires not only social experience but also a certain amount of motoric training. In spite of the high degree of ritualization, loud call displays are not completely fixed in form, but instead are open to individual- and population-specific variation.
Resumo:
The modern subject is what we can call a self-subjecting individual. This is someone in whose inner reality has been implanted a more permanent governability, a governability that works inside the agent. Michel Foucault s genealogy of the modern subject is the history of its constitution by power practices. By a flight of imagination, suppose that this history is not an evolving social structure or cultural phenomenon, but one of those insects (moth) whose life cycle consists of three stages or moments: crawling larva, encapsulated pupa, and flying adult. Foucault s history of power-practices presents the same kind of miracle of total metamorphosis. The main forces in the general field of power can be apprehended through a generalisation of three rationalities functioning side-by-side in the plurality of different practices of power: domination, normalisation and the law. Domination is a force functioning by the rationality of reason of state: the state s essence is power, power is firm domination over people, and people are the state s resource by which the state s strength is measured. Normalisation is a force that takes hold on people from the inside of society: it imposes society s own reality its empirical verity as a norm on people through silently working jurisdictional operations that exclude pathological individuals too far from the average of the population as a whole. The law is a counterforce to both domination and normalisation. Accounting for elements of legal practice as omnihistorical is not possible without a view of the general field of power. Without this view, and only in terms of the operations and tactical manoeuvres of the practice of law, nothing of the kind can be seen: the only thing that practice manifests is constant change itself. However, the backdrop of law s tacit dimension that is, the power-relations between law, domination and normalisation allows one to see more. In the general field of power, the function of law is exactly to maintain the constant possibility of change. Whereas domination and normalisation would stabilise society, the law makes it move. The European individual has a reality as a problem. What is a problem? A problem is something that allows entry into the field of thought, said Foucault. To be a problem, it is necessary for certain number of factors to have made it uncertain, to have made it lose familiarity, or to have provoked a certain number of difficulties around it . Entering the field of thought through problematisations of the European individual human forms, power and knowledge one is able to glimpse the historical backgrounds of our present being. These were produced, and then again buried, in intersections between practices of power and games of truth. In the problem of the European individual one has suitable circumstances that bring to light forces that have passed through the individual through centuries.
Resumo:
Light scattering, or scattering and absorption of electromagnetic waves, is an important tool in all remote-sensing observations. In astronomy, the light scattered or absorbed by a distant object can be the only source of information. In Solar-system studies, the light-scattering methods are employed when interpreting observations of atmosphereless bodies such as asteroids, atmospheres of planets, and cometary or interplanetary dust. Our Earth is constantly monitored from artificial satellites at different wavelengths. With remote sensing of Earth the light-scattering methods are not the only source of information: there is always the possibility to make in situ measurements. The satellite-based remote sensing is, however, superior in the sense of speed and coverage if only the scattered signal can be reliably interpreted. The optical properties of many industrial products play a key role in their quality. Especially for products such as paint and paper, the ability to obscure the background and to reflect light is of utmost importance. High-grade papers are evaluated based on their brightness, opacity, color, and gloss. In product development, there is a need for computer-based simulation methods that could predict the optical properties and, therefore, could be used in optimizing the quality while reducing the material costs. With paper, for instance, pilot experiments with an actual paper machine can be very time- and resource-consuming. The light-scattering methods presented in this thesis solve rigorously the interaction of light and material with wavelength-scale structures. These methods are computationally demanding, thus the speed and accuracy of the methods play a key role. Different implementations of the discrete-dipole approximation are compared in the thesis and the results provide practical guidelines in choosing a suitable code. In addition, a novel method is presented for the numerical computations of orientation-averaged light-scattering properties of a particle, and the method is compared against existing techniques. Simulation of light scattering for various targets and the possible problems arising from the finite size of the model target are discussed in the thesis. Scattering by single particles and small clusters is considered, as well as scattering in particulate media, and scattering in continuous media with porosity or surface roughness. Various techniques for modeling the scattering media are presented and the results are applied to optimizing the structure of paper. However, the same methods can be applied in light-scattering studies of Solar-system regoliths or cometary dust, or in any remote-sensing problem involving light scattering in random media with wavelength-scale structures.
Resumo:
The details of the first total synthesis of a natural thapsane lg containing three contiguous quaternary carbon atoms, starting from cyclogeraniol (9) '5 described. The Claisen rearrangement of 9 with methoxypropene in the presence of a catalytic amount of propionic acid produced ketone 10. Rhodium acetate-catalyzed intramolecular cyclopropanation of a-diazo-&keto ester 12, obtained from 10 via 8-keto ester 8, furnished cyclopropyl keto ester 7. Lithium in liquid ammonia reductive cleavage of cyclopropyl compound 7 gave a 1:l mixture of hydrindanone 6 and keto1 13. Wittig methylenation of 6 furnished ester 21. Epoxidation of 21, followed by BF3-OEt2-catalyzed rearrangement of epoxide 23 afforded hemiacetal 25. Treatment of hemiacetal 25 with triethylsilane in trifluoroacetic acid furnished lactone 22, a degradation product of various thapsanes. Finally, DIBAH reduction of lactone 22 generated the thapsane
Resumo:
The effect of fourteen minor elements (Al, As, B, Bi, C, Ga, Ge, In, N, P, Pb, S, Sb and Sn) on the solubility of oxygen in silicon melt has been estimated using a recently developed theoretical equation, with only fundamental physical parameters such as hard sphere diameter, atomic volume and molar heat of solution at infinite dilution as inputs. The results are expressed in the form of interaction parameters. Although only limited experimental data are available for comparison, the theoretical approach appears to predict the correct sign, but underestimates the magnitude of the interaction between oxygen and alloying elements. The present theoretical approach is useful in making qualitative predications on the effect of minor elements on the solubility of oxygen in silicon melt, when direct measurements are not available.
Resumo:
The enzyme telomerase synthesizes the G-rich DNA strands of the telomere and its activity is often associated with cancer. The telomerase may be therefore responsible for the ability of a cancer cell-to escape apoptosis. The G-rich DNA sequences often adopt tetra-stranded structure, known as the G-quadruplex DNA (G4-DNA). The stabilization of the telomeric DNA into the G4-DNA structures by small molecules has been the focus of many researchers for the design and development of new anticancer agents. The compounds which stabilize the G-quadruplex in the telomere inhibit the telomerase activity. Besides telomeres, the G4-DNA forming sequences are present in the genomic regions of biological significance including the transcriptional regulatory and promoter regions of several oncogenes. Inducing a G-quadruplex structure within the G-rich promoter sequences is a potential way of achieving selective gene regulation. Several G-quadruplex stabilizing ligands are known. Minor groove binding ligands (MGBLs) interact with the double-helical DNA through the minor grooves sequence-specifically and interfere with several DNA associated processes. These MGBLs when suitably modified switch their preference sometimes from the duplex DNA to G4-DNA and stabilize the G4-DNA as well. Herein, we focus on the recent advances in understanding the G-quadruplex structures, particularly made by the human telomeric ends, and review the results of various investigations of the interaction of designed organic ligands with the G-quadruplex DNA while highlighting the importance of MGBL-G-quadruplex interactions.
Resumo:
By means of N-body simulations we investigate the impact of minor mergers on the angular momentum and dynamical properties of the merger remnant. Our simulations cover a range of initial orbital characteristics and gas-to-stellar mass fractions (from 0 to 20%), and include star formation and supernova feedback. We confirm and extend previous results by showing that the specific angular momentum of the stellar component always decreases independently of the orbital parameters or morphology of the satellite, and that the decrease in the rotation velocity of the primary galaxy is accompanied by a change in the anisotropy of the orbits. However, the decrease affects only the old stellar population, and not the new population formed from gas during the merging process. This means that the merging process induces an increasing difference in the rotational support of the old and young stellar components, with the old one lagging with respect to the new. Even if our models are not intended specifically to reproduce the Milky Way and its accretion history, we find that, under certain conditions, the modeled rotational lag found is compatible with that observed in the Milky Way disk, thus indicating that minor mergers can be a viable way to produce it. The lag can increase with the vertical distance from the disk midplane, but only if the satellite is accreted along a direct orbit, and in all cases the main contribution to the lag comes from stars originally in the primary disk rather than from stars in the satellite galaxy. We also discuss the possibility of creating counter-rotating stars in the remnant disk, their fraction as a function of the vertical distance from the galaxy midplane, and the cumulative effect of multiple mergers on their creation.
Resumo:
Addition of boron to cast Ti-6Al-4V alloy leads to significant refinement in grain size, which in turn improves processibilty as well as the mechanical properties of the as-cast alloy. Room temperature tensile and fatigue properties of Wrought Ti-6Al-4V-B alloys with B up to 0.09 wt.% are investigated. Thermo-mechanical processing at 950 degrees C caused kinking of alpha lamellae and alignment of TiB particles in the flow direction with a negligible change in prior beta grain and colony sizes, indicating the absence of dynamic recrystallisation during forging. Characterisation with the aid of X-ray and electron back scattered diffraction reveal a strong basal texture in B free alloy which gets randomised with the 0.09B addition in the forged condition. Marginal enhancement in tensile and fatigue properties upon forging is noted. B free wrought Ti-6Al-4V alloy exhibits better tensile strength as compared to B containing alloy, due to the operation of < c+a > slip on pyramidal planes with high value of CRSS as compared to < a > slip on basal and prismatic planes. Decrease in fatigue strength of Ti-6Al-4V-0.04B in as-cast and the wrought state is observed due to increase in the volume fraction of grain boundary a phase with B addition, which acts as a crack nucleation site. No significant effect of TiB particles on tensile and fatigue properties is observed. (C) 2012 Elsevier B.V. All rights reserved.