1,477 research outputs found
Body size measures, hemostatic and inflammatory markers and risk of venous thrombosis: The Longitudinal Investigation of Thromboembolism Etiology
Obesity is an important venous thrombosis (VT) risk factor but the reasons for this are unclear
Characteristics of Repetitive Thought Associated with Borderline Personality Features: A Multimodal Investigation of Ruminative Content and Style
Increased ruminative style of thought has been well documented in borderline personality disorder (BPD); however, less is known about how the content of rumination relates to domains of BPD features. Relationships between forms of rumination and BPD features were examined in an undergraduate sample with a wide range of BPD features. Participants completed self-report measures of rumination and a free-writing task about their repetitive thought. Rumination on specific themes, including anger rumination, depressive brooding, rumination on interpersonal situations, anxious rumination, and stress-reactive rumination were significantly associated with most BPD features after controlling for general rumination. Coded writing samples suggested that BPD features are associated with repetitive thought that is negative in valence, difficult to control, prolonged, unhelpful, and unresolved. Although rumination is often described as a form of self-focused attention, BPD relationship difficulties were correlated with greater other-focus in the writing samples, which may reflect more interpersonal themes. Across both self-reports and the writing task, the BPD feature of self-destructive behavior was associated specifically with anger and hostility, suggesting this content may play a particularly important role in fueling impulsive behavior. These findings suggest that both the style and the content of repetitive thought may play a role in BPD features
The variable magnetic field of V889 Her and the challenge of detecting exoplanets around young Suns using Gaussian process regression
Discovering exoplanets orbiting young Suns can provide insight into the
formation and early evolution of our own solar system, but the extreme magnetic
activity of young stars obfuscates exoplanet detection. Here we monitor the
long-term magnetic field and chromospheric activity variability of the young
solar analogue V889 Her, model the activity-induced radial velocity variations
and evaluate the impacts of extreme magnetism on exoplanet detection
thresholds. We map the magnetic field and surface brightness for 14 epochs
between 2004 and 2019. Our results show potential 3-4 yr variations of the
magnetic field which evolves from weak and simple during chromospheric activity
minima to strong and complex during activity maxima but without any polarity
reversals. A persistent, temporally-varying polar spot coexists with weaker,
short-lived lower-latitude spots. Due to their different decay time-scales,
significant differential rotation and the limited temporal coverage of our
legacy data, we were unable to reliably model the activity-induced radial
velocity using Gaussian Process regression. Doppler Imaging can be a useful
method for modelling the magnetic activity jitter of extremely active stars
using data with large phase gaps. Given our data and using Doppler Imaging to
filter activity jitter, we estimate that we could detect Jupiter-mass planets
with orbital periods of 3 d. A longer baseline of continuous observations
is the best observing strategy for the detection of exoplanets orbiting highly
active stars.Comment: Accepted by MNRA
The spectral variability and magnetic field characteristics of the Of?p star HD 148937
We report magnetic and spectroscopic observations and modeling of the Of?p
star HD 148937 within the context of the MiMeS LP at the CFHT. Thirty-two high
signal-to-noise ratio circularly polarised (Stokes V) spectra and 13
unpolarised (Stokes I) spectra of HD 148937 were acquired in 2009 and 2010. A
definite detection of a Stokes V Zeeman signature is obtained in the grand mean
of all observations (in both LSD mean profiles and individual spectral lines).
The longitudinal magnetic field inferred from the Stokes V LSD profiles is
consistently negative, in contrast to the essentially zero field strength
measured from the diagnostic null profiles. A period search of equivalent width
measurements confirms the previously-reported 7.03 d variability period. The
variation of equivalent widths is not strictly periodic: we present evidence
for evolution of the amount or distribution of circumstellar plasma.
Interpreting the 7.03 d period as the stellar rotational period within the
context of the ORM, we have phased the equivalent widths and longitudinal field
measurements. The longitudinal field measurements show a weak sinusoidal
variation of constant sign, with extrema out of phase with the H{\alpha}
variation by about 0.25 cycles. The inferred magnetic configuration confirms
the suggestion of Naz\'e et al (2010), who proposed that the weaker variability
of HD 148937 as compared to other members of this class is a consequence of the
stellar geometry. Based on the derived magnetic properties and published wind
characteristics, we find a wind magnetic confinement parameter \eta\ast \simeq
20 and rotation parameter W = 0.12, supporting a picture in which the Halpha
emission and other line variability have their origin in an oblique, rigidly
rotating magnetospheric structure resulting from a magnetically channeled wind.
(Abridged.)Comment: 13 pages, MNRAS. Version 2, small change to Fig. 1
Incorporating social practices in BDI agent systems
When agents interact with humans, either through embodied agents or because
they are embedded in a robot, it would be easy if they could use fixed
interaction protocols as they do with other agents. However, people do not keep
fixed protocols in their day-to-day interactions and the environments are often
dynamic, making it impossible to use fixed protocols. Deliberating about
interactions from fundamentals is not very scalable either, because in that
case all possible reactions of a user have to be considered in the plans. In
this paper we argue that social practices can be used as an inspiration for
designing flexible and scalable interaction mechanisms that are also robust.
However, using social practices requires extending the traditional BDI
deliberation cycle to monitor landmark states and perform expected actions by
leveraging existing plans. We define and implement this mechanism in Jason
using a periodically run meta-deliberation plan, supported by a
metainterpreter, and illustrate its use in a realistic scenario.Comment: An extended abstract of this paper has been accepted for the
Eighteenth International Conference on Autonomous Agents and Multiagent
Systems (AAMAS), 201
A genetic variant on chromosome 9p21 and incident heart failure in the ARIC study
Recent studies showed that polymorphisms on chromosome 9p21 are associated with coronary heart disease (CHD), but few studies examined the association with heart failure (HF), stroke, or other subclinical atherosclerotic diseases. We tested the association of chromosome 9p21 polymorphisms with non-coronary atherosclerotic diseases
Validity of self-report of lipid medication use: The Atherosclerosis Risk in Communities (ARIC) Study
To evaluate the validity of self-reported lipid medication use in an epidemiological study
Pericardial Fat and Myocardial Perfusion in Asymptomatic Adults from the Multi-Ethnic Study of Atherosclerosis
BACKGROUND:Pericardial fat has adverse effects on the surrounding vasculature. Previous studies suggest that pericardial fat may contribute to myocardial ischemia in symptomatic individuals. However, it is unknown if pericardial fat has similar effects in asymptomatic individuals. METHODS:We determined the association between pericardial fat and myocardial blood flow (MBF) in 214 adults with no prior history of cardiovascular disease from the Minnesota field center of the Multi-Ethnic Study of Atherosclerosis (43% female, 56% Caucasian, 44% Hispanic). Pericardial fat volume was measured by computed tomography. MBF was measured by MRI at rest and during adenosine-induced hyperemia. Myocardial perfusion reserve (PR) was calculated as the ratio of hyperemic to resting MBF. RESULTS:Gender-stratified analyses revealed significant differences between men and women including less pericardial fat (71.9±31.3 vs. 105.2±57.5 cm(3), p<0.0001) and higher resting MBF (1.12±0.23 vs. 0.93±0.19 ml/min/g, p<0.0001), hyperemic MBF (3.49±0.76 vs. 2.65±0.72 ml/min/g, p<0.0001), and PR (3.19±0.78 vs. 2.93±0.89, p = 0.03) in women. Correlations between pericardial fat and clinical and hemodynamic variables were stronger in women. In women only (p = 0.01 for gender interaction) higher pericardial fat was associated with higher resting MBF (p = 0.008). However, this association was attenuated after accounting for body mass index or rate-pressure product. There were no significant associations between pericardial fat and hyperemic MBF or PR after multivariate adjustment in either gender. In logistic regression analyses there was also no association between impaired coronary vasoreactivity, defined as having a PR <2.5, and pericardial fat in men (OR, 1.18; 95% CI, 0.82-1.70) or women (OR, 1.11; 95% CI, 0.68-1.82). CONCLUSIONS:Our data fail to support an independent association between pericardial fat and myocardial perfusion in adults without symptomatic cardiovascular disease. Nevertheless, these findings highlight potentially important differences between asymptomatic and symptomatic individuals with respect to the underlying subclinical disease burden
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