30 research outputs found
Weedwacking: Providence College\u27s use of OCLC Greenglass
We will present an overview of our recently completed project to remove unused and obsolete titles from our print collection using OCLC Greenglass
Physics Of Eclipsing Binaries. II. Towards the Increased Model Fidelity
The precision of photometric and spectroscopic observations has been
systematically improved in the last decade, mostly thanks to space-borne
photometric missions and ground-based spectrographs dedicated to finding
exoplanets. The field of eclipsing binary stars strongly benefited from this
development. Eclipsing binaries serve as critical tools for determining
fundamental stellar properties (masses, radii, temperatures and luminosities),
yet the models are not capable of reproducing observed data well either because
of the missing physics or because of insufficient precision. This led to a
predicament where radiative and dynamical effects, insofar buried in noise,
started showing up routinely in the data, but were not accounted for in the
models. PHOEBE (PHysics Of Eclipsing BinariEs; http://phoebe-project.org) is an
open source modeling code for computing theoretical light and radial velocity
curves that addresses both problems by incorporating missing physics and by
increasing the computational fidelity. In particular, we discuss triangulation
as a superior surface discretization algorithm, meshing of rotating single
stars, light time travel effect, advanced phase computation, volume
conservation in eccentric orbits, and improved computation of local intensity
across the stellar surfaces that includes photon-weighted mode, enhanced limb
darkening treatment, better reflection treatment and Doppler boosting. Here we
present the concepts on which PHOEBE is built on and proofs of concept that
demonstrate the increased model fidelity.Comment: 60 pages, 15 figures, published in ApJS; accompanied by the release
of PHOEBE 2.0 on http://phoebe-project.or
Optically measured microvascular blood flow contrast of malignant breast tumors.
Microvascular blood flow contrast is an important hemodynamic and metabolic parameter with potential to enhance in vivo breast cancer detection and therapy monitoring. Here we report on non-invasive line-scan measurements of malignant breast tumors with a hand-held optical probe in the remission geometry. The probe employs diffuse correlation spectroscopy (DCS), a near-infrared optical method that quantifies deep tissue microvascular blood flow. Tumor-to-normal perfusion ratios are derived from thirty-two human subjects. Mean (95% confidence interval) tumor-to-normal ratio using surrounding normal tissue was 2.25 (1.92-2.63); tumor-to-normal ratio using normal tissues at the corresponding tumor location in the contralateral breast was 2.27 (1.94-2.66), and using normal tissue in the contralateral breast was 2.27 (1.90-2.70). Thus, the mean tumor-to-normal ratios were significantly different from unity irrespective of the normal tissue chosen, implying that tumors have significantly higher blood flow than normal tissues. Therefore, the study demonstrates existence of breast cancer contrast in blood flow measured by DCS. The new, optically accessible cancer contrast holds potential for cancer detection and therapy monitoring applications, and it is likely to be especially useful when combined with diffuse optical spectroscopy/tomography
Longitudinal Course of Depressive, Anxiety, and Posttraumatic Stress Disorder Symptoms After Heart Surgery: A Meta-Analysis of 94 Studies
OBJECTIVE: This study aimed to analyze the longitudinal course of depression, anxiety, and posttraumatic stress disorder (PTSD) symptoms in patients with cardiac disease after heart surgery (HS).METHODS: We conducted a systematic review and random-effects meta-analysis of cohort studies in patients undergoing HS, measuring anxiety, depressive, and PTSD symptoms before and at least 30 days thereafter. Subgroup and meta-regression analyses, investigation of publication bias, and quality assessment were undertaken.RESULTS: We included 94 studies relating to 15,561 patients. HS included coronary artery bypass graft surgery, valve replacement, implantable cardioverter-defibrillator placement, left ventricular assist device placement, heart transplantation, and other types of HS. Across studies, symptoms of depression (g = 0.32; 95% confidence interval [CI] = 0.25 to 0.39; p < .001) and anxiety improved after HS (g = 0.52; 95% CI = 0.43 to 0.62; p < .001), whereas PTSD symptoms worsened (g = -0.42; 95% CI = -0.80 to -0.04; p = .032). The reduction of depression and anxiety levels was more pronounced for patients with underlying coronary artery disease and heart failure and persisted for 1 year after HS, whereas the increase in PTSD symptoms returned to baseline after 6 months. Depression improvement was inversely associated with older age, diabetes, hypertension, and dyslipidemia and positively with baseline heart failure. No additional clinical or demographic variables were associated with the course of anxiety symptoms. Quality of included studies was low overall. Publication bias was nonsignificant.CONCLUSIONS: Depressive and anxiety symptoms improve for 1 year after HS, whereas PTSD symptoms might worsen. Older patients and those with metabolic comorbidities, valve disease, or ventricular arrhythmias are at higher risk for continued depressive and anxiety symptoms and should be monitored closely
Clinical characteristics of subjects.
<p>For continuous data such as age and body mass index (BMI), mean standard deviations are shown. For each categorical variable, the number of women is given and the percentage of the total number of women in the group appears in parentheses.</p
Definition of relative blood flows based on local regions.
<p>Definition of relative blood flows based on local regions.</p