897 research outputs found
Temporary Jobs in Ireland: Does Class Influence Job Quality?
Fixed term and casual employment have become increasingly common in OECD countries in the last decade. Research suggests that non-permanent contracts are associated with lower job quality. This paper examines differentials in three indicators of job quality in Ireland: hourly wage, probability of training and level of autonomy. The paper also examines four hypotheses on job quality derived from transaction cost and insider-outsider theories which suggest an important interaction between social class position, non-permanent employment and job quality. Results show that fixed term and casual contracts are associated with lower earnings, less training and lower autonomy.
Inevitability of Plate Tectonics on Super-Earths
The recent discovery of super-Earths (masses less or equal to 10
earth-masses) has initiated a discussion about conditions for habitable worlds.
Among these is the mode of convection, which influences a planet's thermal
evolution and surface conditions. On Earth, plate tectonics has been proposed
as a necessary condition for life. Here we show, that super-Earths will also
have plate tectonics. We demonstrate that as planetary mass increases, the
shear stress available to overcome resistance to plate motion increases while
the plate thickness decreases, thereby enhancing plate weakness. These effects
contribute favorably to the subduction of the lithosphere, an essential
component of plate tectonics. Moreover, uncertainties in achieving plate
tectonics in the one earth-mass regime disappear as mass increases:
super-Earths, even if dry, will exhibit plate tectonic behaviour.Comment: 13 pages, 2 figures and 1 table; in press in ApJ
Rheology of the Mantle
There have been two main avenues of investigation of the rheology of the mantle: theoretical and laboratory studies of the mechanical behavior of solids and direct estimates obtained by comparing geologic observations with model calculations in which rheological parameters are the principal variables. Studies of large-scale mantle flow, such as convection, might also put some constraints on mantle rheology, although at the present better knowledge of the rheology is needed to specify suitable models for investigation.
The main advances of the last 4 years in our understanding of mantle rheology have been in the realization that the lower mantle may be less resistant to creep than was previously believed and in the realization and preliminary investigation of the complexities of the convection problem
The development of a handbook for prospective college students at Somerset High School, Somerset, Massachusetts
Thesis (Ed.M.)--Boston Universit
Does Intraindividual Variability of Personality States Improve Perspective Taking? An Ecological Approach Integrating Personality and Social Cognition
Research integrating cognitive abilities and personality has focused on the role of personality traits. We propose a theory on the role of intraindividual variability of personality states (hereafter state variability) on perspective taking, in particular, the ability to infer other peoples’ mental states. First, we review the relevant research on personality psychology and social cognition. Second, we propose two complementary routes by which state variability relates to anchoring and adjustment in perspective taking. The first route, termed ego-dispersion, suggests that an increased state variability decreases egocentric bias, which reduces anchoring. The second route, termed perspective-pooling, suggests that an increased state variability facilitates efficient adjustment. We also discuss how our theory can be investigated empirically. The theory is rooted in an ecological interpretation of personality and social cognition, and flags new ways for integrating these fields of research
Dynamics of submergence and uplift of a sedimentary basin underlain by a phase-change boundary
A procedure is given for calculating the evolution of a sedimentary basin underlain by a phase-change boundary that is in isostatic equilibrium. The equation of motion of the water depth w(t) as a function of the water depth and as a function of the sedimentation rate ds/dt is Q_w(w) dw/dt + Q_s ds/dt + (1 - ρ_1/ρ_2) dl/dt = 0 where l(t) is the lag of the phase boundary behind the transient equilibrium position. Numerically precise integrals of this equation are given for different time regimes by use of certain approximations for the temperature field that determine dl/dt. Solutions are demonstrated that are attenuated, explosive, or near periodic, depending on the physical parameters used. The results clearly show the possibility of depositing very thick sedimentary sections and the existence of self-sustained oscillations (above and below sea level) for a sedimentary basin of this type
Dynamics of the motion of a phase change boundary to changes in pressure
Because of the significance of both shallow and deep phase changes to geophysical problems, the dynamical response of a phase change to pressure loading was investigated. It was found that the characteristic behavior of the system may be analyzed in terms of simple parameters of the system by using analytic expressions that apply for the initial part and the final part of the motion of the phase boundary. These expressions are obtained from approximations based on generalizations of Neumann's solution for melting at a constant temperature or from simple physical approximations based on the over-all geometry of the model. The range of applicability of the approximations can be obtained from the approximations themselves. The analytic results compare very favorably with exact numerical solutions. The distribution of heat sources and convective heat transport are shown to be generally of minor importance on the motion of the phase boundary; the effect of convective heat transport can be estimated from the analytic approximation. The important parameters are the latent heat of the phase change and the difference in slope between the Clapeyron curve and the temperature distribution in the earth. In addition, the long-term motion depends primarily on the over-all geometry of the model and the boundary condition at depth. The analytic results indicate the time at which thermal blanketing by sediments becomes important and the effect of the rate of sedimentation on the response of the system; they also define slow and fast sedimentation and secular equilibrium. The effect of isostasy in conjunction with a shallow phase change is shown to be of major importance, and for certain cases the sediment thickness that can accumulate in a sedimentary basin may depend only on the sedimentation rate and not the initial depth of the basin. The analytic results permit a more physical discussion of the problem, since the functional dependence of the solution on the parameters may be seen. In addition, important results for a variety of models can be obtained by relatively simple calculations, without resorting to separate numerical solutions for each model considered
O'Connell Receives 2000 Inge Lehmann Medal
Richard J. O'Connell was awarded the Inge Lehmann Medal at the AGU Fall Meeting Honors Ceremony, which was held on December 17, 2000, in San Francisco, California. The medal recognizes outstanding contributions to the understanding of the structure, composition, and dynamics of the Earth's mantle and core
The Use of Time in Storytelling
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A total of 18 experimental corpora of spontaneous speech in five languages (English, Finnish, French, German, and Spanish) were examined under the hypothesis that they are characterized by commonalities in the use of time. Each study was based on the same speech type, story telling elicited by pictorial materials. The temporal measures were speech and articulation rates, pause duration, phrase length, and percentage of pause time/total time. The hypothesis was confirmed except for studies carried out with identifiably variant methodologies. Further support for the hypothesis was found by contrasting the use of time characteristic of interviewees' speech
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