1,639 research outputs found
Extraversion and adaptive performance: Integrating trait activation and socioanalytic personality theories at work
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordBoth trait activation and socioanalytic personality theories clarify the personality â performance relationship at work. We argue that extraversion needs to be interactively combined with both social competency (socioanalytic theory) and an activating context (trait activation theory) to demonstrate effects on a relevant type of work performance. Specifically, the aim of the present study was to examine extraversion's association with adaptive performance when combined with social competency and context (i.e., climate for personal initiative). Our results demonstrate that the three-way interaction (i.e., extraversion Ă social competency Ă climate for initiative) has a significant relationship with adaptive performance, such that the extraversionâperformance association is strengthened when both social competency and climate for initiative are heightened. Our findings suggest that personality scholars should consider both socioanalytic and trait activation perspectives when investigating performance prediction. We discuss implications, strengths, limitations, and directions for future research
Political skill and manager performance: exponential and asymptotic relationships due to differing levels of enterprising job demands
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordPolitical skill, a social competence that enables individuals to achieve goals due to their understanding of and influence upon others at work, can play an important role in manager performance. We argue that the political skillâmanager performance relationship varies as a nonlinear function of differing levels of enterprising job demands (i.e., working with and through people). A large number of occupations have some enterprising features, but, across occupations, management roles typically contain even greater enterprising expectations. However, relatively few studies have examined the enterprising work context (e.g., enterprising demands) of managers. Specifically, under conditions of high enterprising job demands, we argue and find that, as political skill increases, there is an associated exponential increase in enterprising performance, with growth beyond the mean of political skill resulting in outsized performance gains. Whereas, under conditions of low (relative to other managers) enterprising job demands, political skill will have an asymptotic relationship with enterprising job performance, such that the positive relationship becomes weaker as political skill grows, with increases on political skill beyond the mean resulting in minimal performance improvements. Our hypotheses are generally supported, and these findings have important implications for managers, as the performance gains in managerial roles were shown to be a joint function of manager political skill and enterprising job demands
Towards sex-specific osteoarthritis risk models: evaluation of risk factors for knee osteoarthritis in males and females
Objectives The aim of this study was to identify sex-specific prevalence and strength of risk factors for the incidence of radiographic knee OA (incRKOA). Methods Our study population consisted of 10â958 Rotterdam Study participants free of knee OA in one or both knees at baseline. One thousand and sixty-four participants developed RKOA after a median follow-up time of 9.6âyears. We estimated the association between each available risk factor and incRKOA using sex stratified multivariate regression models with generalized estimating equations. Subsequently, we statistically tested sex differences between risk estimates and calculated the population attributable fractions (PAFs) for modifiable risk factors. Results The prevalence of the investigated risk factors was, in general, higher in women compared with men, except that alcohol intake and smoking were higher in men and high BMI showed equal prevalence. We found significantly different risk estimates between men and women: high level of physical activity [relative risk (RR) 1.76 (95% CI: 1.29â2.40)] or a Kellgren and Lawrence score 1 at baseline [RR 5.48 (95% CI: 4.51â6.65)] was higher in men. Among borderline significantly different risk estimates was BMI â„27, associated with higher risk for incRKOA in women [RR 2.00 (95% CI: 1.74â2.31)]. The PAF for higher BMI was 25.6% in women and 19.3% in men. Conclusion We found sex-specific differences in both presence and relative risk of several risk factors for incRKOA. Especially BMI, a modifiable risk factor, impacts women more strongly than men. These risk factors can be used in the development of personalized prevention strategies and in building sex-specific prediction tools to identify high risk profile patients
Epidemiological Interactions between Urogenital and Intestinal Human Schistosomiasis in the Context of Praziquantel Treatment across Three West African Countries
© 2015 Knowles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
Tomographic Separation of Composite Spectra. IX. The Massive Close Binary HD 115071
We present the first orbital elements for the massive close binary, HD
115071, a double-lined spectroscopic binary in a circular orbit with a period
of 2.73135 +/- 0.00003 days. The orbital semiamplitudes indicate a mass ratio
of M_2/M_1 = 0.58 +/- 0.02 and yet the stars have similar luminosities. We used
a Doppler tomography algorithm to reconstruct the individual component optical
spectra, and we applied well known criteria to arrive at classifications of
O9.5 V and B0.2 III for the primary and secondary, respectively. We present
models of the Hipparcos light curve of the ellipsoidal variations caused by the
tidal distortion of the secondary, and the best fit model for a Roche-filling
secondary occurs for an inclination of i = 48.7 +/- 2.1 degrees. The resulting
masses are 11.6 +/- 1.1 and 6.7 +/- 0.7 solar masses for the primary and
secondary, respectively, so that both stars are very overluminous for their
mass. The system is one of only a few known semi-detached, Algol-type binaries
that contain O-stars. We suggest that the binary has recently emerged from
extensive mass transfer (possibly through a delayed contact and common envelope
process).Comment: Submitted to Ap
Statistics and characteristics of MgII absorbers along GRB lines of sight observed with VLT-UVES
We analyse the properties of MgII absorption systems detected along the
sightlines toward GRBs using a sample of 10 GRB afterglow spectra obtained with
VLT-UVES over the past six years. The S/N ratio is sufficiently high that we
can extend previous studies to smaller equivalent widths (typically Wr>0.3A).
Over a pathlength of Delta(z)~14 the number of weak absorbers detected is
similar along GRB and QSO lines of sight, while the number of strong systems is
larger along GRB lines of sight with a 2-sigma significance. Using intermediate
and low resolution observations reported in the literature, we increase the
absorption length for strong systems to Delta(z)=31.5 (about twice the path
length of previous studies) and find that the number density of strong MgII
systems is a factor of 2.1+/-0.6 higher (about 3-sigma significance) toward
GRBs as compared to QSOs, about twice smaller however than previously reported.
We divide the sample in three redshift bins and we find that the number density
of strong MgII is larger in the low redshift bins. We investigate in detail the
properties of strong MgII systems observed with UVES. Both the estimated dust
extinction in strong GRB MgII systems and the equivalent width distribution are
consistent with what is observed for standard QSO systems. We find also that
the number density of (sub)-DLAs per unit redshift in the UVES sample is
probably twice larger than what is expected from QSO sightlines which confirms
the peculiarity of GRB lines of sight. These results indicate that neither a
dust extinction bias nor different beam sizes of the sources are viable
explanations for the excess. It is still possible that the current sample of
GRB lines of sight is biased by a subtle gravitational lensing effect. More
data and larger samples are needed to test this hypothesis. (abridged)Comment: 12 pages, 10 figures; accepted for publication in A&A (12 June 2009
Probing the complex environments of GRB host galaxies and intervening systems: high resolution spectroscopy of GRB050922C
The aim of this paper is to investigate the environment of gamma ray bursts
(GRBs) and the interstellar matter of their host galaxies. We use to this
purpose high resolution spectroscopic observations of the afterglow of
GRB050922C, obtained with UVES/VLT 3.5 hours after the GRB event. We found
that, as for most high resolution spectra of GRBs, the spectrum of the
afterglow of GRB050922C is complex. At least seven components contribute to the
main absorption system at z=2.1992. The detection of lines of neutral elements
like MgI and the detection of fine-structure levels of the ions FeII, SiII and
CII allows us to separate components in the GRB ISM along the line of sight.
Moreover, in addition to the main system, we have analyzed the five intervening
systems between z = 2.077 and z = 1.5664 identified along the GRB line of
sight. GRB afterglow spectra are very complex, but full of information. This
can be used to disentangle the contribution of the different parts of the GRB
host galaxy and to study their properties. Our metallicity estimates agree with
the scenario of GRBs exploding in low metallicity galaxiesComment: 11 pages, 12 figures, accepted by A&
UVES - VLT High Resolution Spectroscopy of GRB Afterglows
We present early time, high resolution spectroscopy of three GRB afterglows:
GRB050730, GRB050922C and GRB060418. These data give us precious information on
the kinematics, ionization and metallicity of the interstellar matter of GRB
host galaxies up to a redshift z = 4, and of intervening absorbers along the
line of sight. The absorption spectra show that elements are present both with
high and low ionization states, and even forbidden, fine structure levels are
commonly observed. These features allow us to evaluate the physical parameters
of the absorbing gas. In details, the density of the gas regions lie in the
range n = 10 - 10^6 cm-3, and the temperatures are of the order of T = 10^3 -
10^4 K. The metallicity of the GRB host galaxies is computed using the hydrogen
absorption features. We find undersolar abundances for our GRBs, namely, Z =
0.001 - 0.01. However, depletion has not been considered. It can be taken into
account using as metallicity indicators Zn and Cr, which tend to remain in the
gas phase. We find metallicities higher than the previous values and in
agreement with other measurements for GRB host galaxies. Finally, the observed
[C/Fe] ratio for GRB050730 (z = 3.967) agrees with values expected for a galaxy
younger than a Gyr undergoing bursts of star-formation. In addition, the [C/Fe]
ratio evaluated component by component can give informations on the relative
distances of the components from the GRB explosion site, since Fe dust is more
efficiently destroyed than graphite.Comment: 8 pages, 11 figure, To appear in "The Multicoloured Landscape of
Compact Objects and their Explosive Progenitors: Theory vs Observations"
(Cefalu, Sicily, June 2006). Eds. L. Burderi et al. (New York: AIP
Inhaled PGE1 in neonates with hypoxemic respiratory failure: two pilot feasibility randomized clinical trials.
BackgroundInhaled nitric oxide (INO), a selective pulmonary vasodilator, has revolutionized the treatment of neonatal hypoxemic respiratory failure (NHRF). However, there is lack of sustained improvement in 30 to 46% of infants. Aerosolized prostaglandins I2 (PGI2) and E1 (PGE1) have been reported to be effective selective pulmonary vasodilators. The objective of this study was to evaluate the feasibility of a randomized controlled trial (RCT) of inhaled PGE1 (IPGE1) in NHRF.MethodsTwo pilot multicenter phase II RCTs are included in this report. In the first pilot, late preterm and term neonates with NHRF, who had an oxygenation index (OI) of â„15 and <25 on two arterial blood gases and had not previously received INO, were randomly assigned to receive two doses of IPGE1 (300 and 150 ng/kg/min) or placebo. The primary outcome was the enrollment of 50 infants in six to nine months at 10 sites. The first pilot was halted after four months for failure to enroll a single infant. The most common cause for non-enrollment was prior initiation of INO. In a re-designed second pilot, co-administration of IPGE1 and INO was permitted. Infants with suboptimal response to INO received either aerosolized saline or IPGE1 at a low (150 ng/kg/min) or high dose (300 ng/kg/min) for a maximum duration of 72 hours. The primary outcome was the recruitment of an adequate number of patients (nâ=â50) in a nine-month-period, with fewer than 20% protocol violations.ResultsNo infants were enrolled in the first pilot. Seven patients were enrolled in the second pilot; three in the control, two in the low-dose IPGE1, and two in the high-dose IPGE1 groups. The study was halted for recruitment futility after approximately six months as enrollment targets were not met. No serious adverse events, one minor protocol deviation and one pharmacy protocol violation were reported.ConclusionsThese two pilot RCTs failed to recruit adequate eligible newborns with NHRF. Complex management RCTs of novel therapies for persistent pulmonary hypertension of the newborn (PPHN) may require novel study designs and a longer period of time from study approval to commencement of enrollment.Trial registrationCLINICALTRIALS.GOV: Pilot one: NCT number: 00598429 registered on 10 January 2008. Last updated: 3 February 2011. Pilot two: NCT number: 01467076 17 October 2011. Last updated: 13 February 2013
UVES/VLT high resolution absorption spectroscopy of the GRB080330 afterglow: a study of the GRB host galaxy and intervening absorbers
We study the Gamma Ray Burst (GRB) environment and intervening absorbers by
analyzing the optical absorption features produced by gas surrounding the GRB
or along its line of sight. We analyzed high resolution spectroscopic
observations (R=40000, S/N=3 - 6) of the optical afterglow of GRB080330, taken
with UVES at the VLT ~ 1.5 hours after the GRB trigger. The spectrum
illustrates the complexity of the ISM of the GRB host galaxy at z = 1.51 which
has at least four components in the main absorption system. We detect strong
FeII, SiII, and NiII excited absorption lines associated with the bluemost
component only. In addition to the host galaxy, at least two more absorbers
lying along the line of sight to the afterglow have been detected in the
redshift range 0.8 < z < 1.1, each exhibiting MgII absorption. For the bluemost
component in the host galaxy, we derive information about its distance from the
site of the GRB explosion. We do so by assuming that the excited absorption
lines are produced by indirect UV pumping, and compare the data with a time
dependent photo-excitation code. The distance of this component is found to be
280+40-50 pc, which is lower than found for other GRBs (1 - 6 kpc). We identify
two additional MgII absorbers, one of them with a rest frame equivalent width
larger than 1A. The distance between the GRB and the absorber measured in this
paper confirms that the power of the GRB radiation can influence the conditions
of the interstellar medium up to a distance of at least several hundred pc. For
the intervening absorbers, we confirm the trend that on average one strong
intervening system is found per afterglow, as has been noted in studies
exhibiting an excess of strong MgII absorbers along GRB sightlines compared to
quasars.Comment: 8 Pages, 7 ps figures, A&A in pres
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