6,405 research outputs found
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Loneliness and life satisfaction amongst three cultural groups
Abstract
Studies into loneliness and life satisfaction have rarely assessed the role of culture in moderating the
relationship between these variables. The present study examined the relationship between loneliness and life
satisfaction using data from three nonstudent samples collected from Italian, Anglo-Canadian and
Chinese-Canadian populations. A total of 206 respondents completed the Revised UCLA Loneliness Scale
(Russell, Peplau, & Cutrona, 1980) and the Satisfaction with Life Scale (Diener, Emmons, Larsen, & Griffin,
1985). Two contrasting hypotheses were compared: one, a āpostmodernā hypothesis, predicting that the
relationship between life satisfaction and loneliness would be stronger in our individualist sample of
Anglo-Canadians, and a second, ārelationalā hypothesis predicting this association to be strongest in our
collectivist, Chinese-Canadian sample. Our findings demonstrated that culture has a small but significant
impact on the relationship between loneliness and life satisfaction, and, consistent with the relational
hypothesis, the relationship between the two concepts was strongest among our Chinese-Canadian
respondents and weakest among our Anglo-Canadian participants This finding is discussed in the context
of the strong expectations of social cohesion in collectivist societies
Short-term debt maturity, monitoring and accruals-based earnings management
Most prior studies assume a positive relation between debt and earnings management, consistent with the financial distress theory. However, the empirical evidence for financial distress theory is mixed. Another stream of studies argues that lenders of short-term debt play a monitoring role over management, especially when the firmās creditworthiness is not in doubt. To explore the implications of these arguments on managersā earnings management incentives, we examine a sample of US firms over the period 2003ā2006 and find that short-term debt is positively associated with accruals-based earnings management (measured by discretionary accruals), consistent with the financial distress theory. We also find that this relation is significantly weaker for firms that are of higher creditworthiness (i.e. investment grade firms), consistent with monitoring benefits outweighing financial distress reasons for managing earnings
Characterization of highly-oriented ferroelectric Pb_xBa_(1-x)TiO_3
Pb_xBa_(1-x)TiO_3 (0.2 ā¾ x ā¾ 1) thin films were deposited on single-crystal MgO as well as amorphous Si_3N_4/Si substrates using biaxially textured MgO buffer templates, grown by ion beam-assisted deposition (IBAD). The ferroelectric films were stoichiometric and highly oriented, with only (001) and (100) orientations evident in x-ray diffraction (XRD) scans. Films on biaxially textured templates had smaller grains (60 nm average) than those deposited on single-crystal MgO (300 nm average). Electron backscatter diffraction (EBSD) has been used to study the microtexture on both types of substrates and the results were consistent with x-ray pole figures and transmission electron microscopy (TEM) micrographs that indicated the presence of 90Ā° domain boundaries, twins, in films deposited on single-crystal MgO substrates. In contrast, films on biaxially textured substrates consisted of small single-domain grains that were either c or a oriented. The surface-sensitive EBSD technique was used to measure the tetragonal tilt angle as well as in-plane and out-of-plane texture. High-temperature x-ray diffraction (HTXRD) of films with 90Ā° domain walls indicated large changes, as much as 60%, in the c and a domain fractions with temperature, while such changes were not observed for Pb_xBa_(1-x)TiO_3 (PBT) films on biaxially textured MgO/Si_3N_4/Si substrates, which lacked 90Ā° domain boundaries
Graded ferroelectric capacitors with robust temperature characteristics
Ferroelectric thin films offer the possibility of engineering the dielectric response for tunable components in frequency-agile rf and microwave devices. However, this approach often leads to an undesired temperature sensitivity. Compositionally graded ferroelectric films have been explored as a means of redressing this sensitivity, but experimental observations vary depending on geometry and other details. In this paper, we present a continuum model to calculate the capacitive response of graded ferroelectric films with realistic electrode geometries by accurately accounting for the polarization distribution and long-range electrostatic interactions. We show that graded c-axis poled BaxSr_(1āxT)iO_3 BST parallel plate capacitors are ineffective while graded a-axis poled BST coplanar capacitors with interdigitated electrodes are extremely effective in obtaining high and temperature-stable dielectric properties
Expression of O-linked N-acetylglucosamine modified proteins and production and characterization of chlamydia trachomatis CT663
O-linked Ć¢-N-acetylglucosamine is a regulatory post translational modification. This modification occurs on nearly all functional classes of proteins, in the nucleus and cytoplasm. O-GlcNAc is added to serine or threonine by O-GlcNAc transferase and removed by O-GlcNAcase. Previous attempts to study O-GlcNAc-modified proteins have resulted in low yields, making 3-dimensional structure determination impossible. In this dissertation O-GlcNAc transferase will be co-expressed with domains of human cAMP responsive element-binding protein (CREB1) and Abelson tyrosine-kinase 2 (ABL2) in E. coli, to produce O-GlcNAc-modified protein. The O-GlcNAc-modified protein was expressed in a variety of E. coli cell lines at a variety of conditions, but only small quantities of insoluble protein were produced. A glycosidase was suspected due to the disappearance of the O-GlcNAc modification from the protein. O-(2-acetamido-2-dexoy-dglucopyranosylidene) amino-N-phenylcarbamate (PUGNAc), a Ć¢-N-acetylglucosaminidase inhibitor, was added to the culture media and increased the production of O-GlcNAc-modified protein. This was the first evidence that Ć¢-N-acetylglucosaminidase (NagZ), an E. coli enzyme, cleaves O-GlcNAc from proteins in vivo. NagZ was isolated and shown to cleave O-GlcNAc from a synthetic O-GlcNAc-peptide in vitro. In E. coli, NagZ cleaves the GlcNAc-Ć¢1,4-N-acetylmuramic acid linkage to recycle peptidoglycan in the cytoplasm. A NagZ knockout showed no activity towards the O-GlcNAc-peptide, confirming NagZ as the enzyme responsible for cleaving O-GlcNAc from our glycoprotein expressed in vivo. O-GlcNAc-modified protein produced by the NagZ knockout (āNagZ) co-expression system is highly glycosylated and can be resolubilized from the pellet. The āNagZ is a step closer to production of milligram quantities of O-GlcNAc-modified protein for structure determination
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Fatalism, Social Support and Mental Health in Four Former Soviet Cultures
Research on social support has identified differences in levels of support between cultures, but has provided only a limited explanation of the role of values or beliefs in accounting for such variations. In this paper we examine the relationship between fatalism and perceived support amongst 2672 respondents in four former Soviet States (Russia, Georgia, Ukraine and Belorussia), with participants drawn from groups of manual workers, managers, civil servants, students and the retired in these four countries. We also examine the consequences of such social support for mental health across these nations. Findings indicate a small but significant moderator effect for fatalism on the relationship between social support and mental health. These results are discussed in the context of the continuing economic and social challenges facing the citizens of these nations
The Long-term Dynamical Evolution of Disk-fragmented Multiple Systems in the Solar Neighborhood
The origin of very low-mass hydrogen-burning stars, brown dwarfs (BDs), and planetary-mass objects (PMOs) at
the low-mass end of the initial mass function is not yet fully understood. Gravitational fragmentation of
circumstellar disks provides a possible mechanism for the formation of such low-mass objects. The kinematic and
binary properties of very low-mass objects formed through disk fragmentation at early times (<10 Myr) were
discussed in our previous paper. In this paper we extend the analysis by following the long-term evolution of diskfragmented
systems up to an age of 10 Gyr, covering the ages of the stellar and substellar populations in the
Galactic field. We find that the systems continue to decay, although the rates at which companions escape or
collide with each other are substantially lower than during the first 10 Myr, and that dynamical evolution is limited
beyond 1 Gyr. By t = 10 Gyr, about one third of the host stars are single, and more than half have only one
companion left. Most of the other systems have two companions left that orbit their host star in widely separated
orbits. A small fraction of companions have formed binaries that orbit the host star in a hierarchical triple
configuration. The majority of such double-companion systems have internal orbits that are retrograde with respect
to their orbits around their host stars. Our simulations allow a comparison between the predicted outcomes of disk
fragmentation with the observed low-mass hydrogen-burning stars, BDs, and PMOs in the solar neighborhood.
Imaging and radial velocity surveys for faint binary companions among nearby stars are necessary for verification
or rejection of the formation mechanism proposed in this paper
The effect of the dynamical state of clusters on gas expulsion and infant mortality
The star formation efficiency (SFE) of a star cluster is thought to be the
critical factor in determining if the cluster can survive for a significant
(>50 Myr) time. There is an often quoted critical SFE of ~30 per cent for a
cluster to survive gas expulsion. I reiterate that the SFE is not the critical
factor, rather it is the dynamical state of the stars (as measured by their
virial ratio) immediately before gas expulsion that is the critical factor. If
the stars in a star cluster are born in an even slightly cold dynamical state
then the survivability of a cluster can be greatly increased.Comment: 6 pages, 2 figures. Review talk given at the meeting on "Young
massive star clusters - Initial conditions and environments", E. Perez, R. de
Grijs, R. M. Gonzalez Delgado, eds., Granada (Spain), September 2007,
Springer: Dordrecht. Replacement to correct mistake in a referenc
Highly neurotic never-depressed students have negative biases in information processing
BACKGROUND: Cognitive theories associate depression with negative biases in information processing. Although negatively biased cognitions are well documented in depressed patients and to some extent in recovered patients, it remains unclear whether these abnormalities are present before the first depressive episode. METHOD: High neuroticism (N) is a well-recognized risk factor for depression. The current study therefore compared different aspects of emotional processing in 33 high-N never-depressed and 32 low-N matched volunteers. Awakening salivary cortisol, which is often elevated in severely depressed patients, was measured to explore the neurobiological substrate of neuroticism. RESULTS: High-N volunteers showed increased processing of negative and/or decreased processing of positive information in emotional categorization and memory, facial expression recognition and emotion-potentiated startle (EPS), in the absence of global memory or executive deficits. By contrast, there was no evidence for effects of neuroticism on attentional bias (as measured with the dot-probe task), over-general autobiographical memory, or awakening cortisol levels. CONCLUSIONS: These results suggest that certain negative processing biases precede depression rather than arising as a result of depressive experience per se and as such could in part mediate the vulnerability of high-N subjects to depression. Longitudinal studies are required to confirm that such cognitive vulnerabilities predict subsequent depression in individual subjects
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