Search results for "Interest"
showing 10 items of 624 documents
Integrated simulation and optimization models for tracking international fixed income indices
2001
Portfolio managers in the international fixed income markets must address jointly the interest rate risk in each market and the exchange rate volatility across markets. This paper develops integrated simulation and optimization models that address these issues in a common framework. Monte Carlo simulation procedures generate jointly scenarios of interest and exchange rates and, thereby, scenarios of holding period returns of the available securities. The portfolio manager’s risk tolerance is incorporated either through a utility function or a (modified) mean absolute deviation function. The optimization models prescribe asset allocation weights among the different markets and also resolve b…
Linear and nonlinear interest rate exposure in Spain
2010
PurposeThis paper aims to carry out a comprehensive analysis of the influence of interest rate risk on Spanish firms at the industry level.Design/methodology/approachThe methodology employed has its origin in the two‐index linear regression model proposed by Stone. This traditional interest rate exposure model has been extended in this paper to allow for a nonlinear exposure component as well as the presence of asymmetric behaviour in the exposure pattern.FindingsInterest rate exposure is not homogeneous for all the Spanish industries. In line with other markets, highly leveraged industries (construction and real estate), regulated industries (electrical and utilities), and banking industry…
Perfusion MRI in normal and abnormal pituitary gland. A preliminary study.
1997
Perfusion MRI (magnetic resonance imaging) of the pituitary gland was performed in 20 healthy volunteers and 63 patients with various lesions involving the pituitary gland. All patients underwent sequential contrast-enhanced MRI using spoiled gradient recalled sequences with high temporal resolution (7 seconds). Four pituitary areas (pituitary stalk, posterior lobe, postero-superior, and antero-inferior adenohypophysis) were tested with a selected region of interest. Maximal contrast percentual variation was calculated. The timing of enhancement in normal patients matched perfectly with normal pituitary vascularization. Abnormal timing in pathological condition was investigated.
Emergence of ovulatory cycles with aging in women with polycystic ovary syndrome (PCOS) alters the trajectory of cardiovascular and metabolic risk fa…
2013
Abstract STUDY QUESTION: What alters cardiovascular and metabolic risk factors with aging in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Lipid parameters, mainly low-density lipoprotein (LDL) cholesterol, increase with aging, but not in women who attain ovulatory cycles. WHAT IS KNOWN ALREADY: Cardiovascular and metabolic parameters tend to increase with aging, but this has not been shown in a prospective longitudinal study in women with PCOS. Correlates of these changes have not been identified. STUDY DESIGN: A prospective cohort of 118 hyperandrogenic women with PCOS who were followed from the age of 20-25 years at 5 year intervals for 20 years. PARTICIPANTS/MATERIALS, SE…
A semi-automatic approach for epicardial adipose tissue segmentation and quantification on cardiac CT scans
2019
Abstract Many studies have shown that epicardial fat is associated with a higher risk of heart diseases. Accurate epicardial adipose tissue quantification is still an open research issue. Considering that manual approaches are generally user-dependent and time-consuming, computer-assisted tools can considerably improve the result repeatability as well as reduce the time required for performing an accurate segmentation. Unfortunately, fully automatic strategies might not always identify the Region of Interest (ROI) correctly. Moreover, they could require user interaction for handling unexpected events. This paper proposes a semi-automatic method for Epicardial Fat Volume (EFV) segmentation a…
Correlation of cerebral blood flow and treatment effects of repetitive transcranial magnetic stimulation in depressed patients.
2002
The aims of this study were to: (1) assess the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity in depressed patients as measured by single photon emission tomography (SPECT); (2) evaluate the predictive value of brain SPECT on the antidepressant efficacy of rTMS. Patients (n=17) received 1600 rTMS stimuli at a rate of 10 Hz, 5 days per week for 2 weeks to the left dorsolateral prefrontal cortex. Whole brain SPECT data were acquired using Tc99m-Bicisate. Regional cerebral blood flow (rCBF) was correlated with the % change in the 28-item Hamilton Depression Rating Scale Score (Δ-HDRS) and a semiquantitative region of interest (ROI) analysis was conducted. Prio…
Digital assessment of MRI for lumbar disc desiccation. A comparison of digital versus subjective assessments and digital intensity profiles versus di…
1994
During magnetic resonance imaging, a vast amount of digital data on anatomic structures is translated into images, which are then assessed subjectively. The development of an objective, sensitive method to directly assess the digital data would have clear benefits, particularly for clinical research on disc degeneration. The study goals were to develop a method of digital assessment of disc desiccation and to compare digital signal intensity profiles with discographic patterns and macroanatomic findings. Proton density-weighted MRIs were obtained from 45 males (9-77 years) and digital analysis was done with a freely selectable region of interest facility. The adjacent cerebrospinal fluid (C…
Resting-State Functional Connectome in Patients with Brain Tumors Before and After Surgical Resection
2020
Purpose: High-grade glioma surgery has evolved around the principal belief that a safe maximal tumor resection improves symptoms, quality of life, and survival. Mapping brain function has been recently improved by resting-state functional magnetic resonance imaging (rest-fMRI), a novel imaging technique that explores networks connectivity at “rest.” Methods: This prospective study analyzed 10 patients with high-grade glioma in whom rest-fMRI connectivity was assessed both in single-subject and in group analysis before and after surgery. Seed-based functional connectivity analysis was performed with CONN toolbox. Network identification focused on 8 major functional connectivity networks. A v…
Presurgical evaluation of bony implant sites using panoramic radiography and cone beam computed tomography—influence of medical education
2017
The aim of this study was to compare the subjective quality rating of panoramic radiography (PAN) and CBCT in the planning of dental implant procedures by clinicians with different educational backgrounds.Radiographic images (PAN and CBCT) of 42 patients were examined as follows: the maxillary (MX) anterior region of patients, the MX posterior region of 16 patients and the mandibular (MD) posterior region of 16 patients. These sites were used for planning of dental implant insertion. Data sets were analyzed by examiners with different training backgrounds: three general practitioners (GP), three oral surgeons (OS) and three maxillofacial surgeons (MS). A standardized questionnaire in a stan…
Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload.
2011
Purpose To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. Materials and Methods Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated. Results For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was su…