Search results for " Nonparametric"

Distribution Dynamics and Nonlinear Growth

2003

How do normalization schemes affect net spillovers? A replication of the Diebold and Yilmaz (2012) study

2019

Abstract This paper replicates the Diebold and Yilmaz (2012) study on the connectedness of the commodity market and three other financial markets: the stock market, the bond market, and the FX market, based on the Generalized Forecast Error Variance Decomposition, GEFVD. We show that the net spillover indices (of directional connectedness), used to assess the net contribution of one market to overall risk in the system, are sensitive to the normalization scheme applied to the GEFVD. We show that, considering data generating processes characterized by different degrees of persistence and covariance, a scalar-based normalization of the Generalized Forecast Error Variance Decomposition is pref…

Landmark identification on direct digital versus film-based cephalometric radiographs: A human skull study

2002

The purpose of this study was to investigate differences in landmark identification on vertically scanned, direct digital and conventional (18 x 24 cm) cephalometric radiographs. Eight observers, all orthodontists or postgraduate orthodontic students, recorded 6 landmarks twice on 3 digital and 3 conventional cephalograms obtained from 3 human skulls in a standardized fashion. Digital images were displayed on a 15.1-in TFT monitor in 3:1 mode (20 x 26 cm). Recordings were transferred into standardized coordinate systems and evaluated separately for each coordinate. After correcting for magnification, precision was assessed with Maloney-Rastogi tests, and intraobserver and interobserver repr…

Evaluation of a digital radiography to estimate working length

1997

The working lengths obtained with different methods in single-rooted teeth were compared. An endodontic rule in millimeters and calipers was used as a direct method of measurement (on endodontic files). As indirect methods, measurements were taken from conventional x-rays with calipers and with a digital radiological measurement system. No statistically significant differences were obtained between the direct and indirect methods. Three vertical angulations were taken for the indirect methods (0 degree, 15 degrees, and 30 degrees). No significant differences were found between results for the two indirect methods versus the standard method except for the 30 degrees angulation, which resulte…

Acute effects of 1,1,1-trichloroethane on human olfactory functioning.

2004

Background Animal experiments indicate that 1,1,1-trichloroethane can cause degeneration of the olfactory epithelium. The effects of 1,1,1-trichloroethane on human odor perception still have not been investigated. The goal of this study was to learn more about acute effects of 1,1,1-trichloroethane. Methods Twelve healthy, nonsmoking students were exposed to 200 and 20 ppm (control) 1,1,1-trichloroethane in an exposure chamber for 4 hours according to a crossover design. Olfactory functioning was investigated with the Sniffin’ Sticks. The test includes the determination of the detection threshold for n-butanol and an odor identification test. Results After 1 hour of exposure to 200 ppm 1,1,…

Is first-line single-agent mitoxantrone in the treatment of high-risk metastatic breast cancer patients as effective as combination chemotherapy? No …

2002

BACKGROUND: To determine whether patients with high-risk metastatic breast cancer draw benefit from combination chemotherapy as first-line treatment. PATIENTS AND METHODS: A total of 260 women with measurable metastatic breast cancer fulfilling high-risk criteria, previously untreated with chemotherapy for their metastatic disease, were randomized to receive either mitoxantrone 12 mg/m(2) or the combination of fluorouracil 500 mg/m(2), epirubicin 50 mg/m(2) and cyclophosphamide 500 mg/m(2) (FEC) every 3 weeks. Treatment was continued until complete remission plus two cycles, or until disease progression. In the case of partial remission or stable disease, treatment was stopped after 12 cycl…

Apolipoprotein E genotype does not influence the progression of multiple sclerosis

2003

OBJECTIVE: To investigate the association between apolipoprotein E (APOE) polymorphisms and the progression of MS. METHODS: We investigated 428 subjects affected by clinically defined MS, with a disease duration of at least three years. We collected data concerning the age at onset of MS, clinical type, disease duration and disability according to the expanded disability status scale (EDSS). We also calculated the progression index (PI) to evaluate disease progression. APOE genotyping and the -491 A/T polymorphism of the APOE promoter were determined. RESULTS: No association was observed between the APOE epsilon4 allele and clinical characteristics of our study population. We also investiga…

No evidence of beneficial effects of plasmapheresis in natalizumab-associated PML

2017

Objective:To examine retrospectively the effects of plasmapheresis (PLEX) on the survival and clinical outcomes of patients with multiple sclerosis (MS) and natalizumab (NTZ)–associated progressive multifocal leukoencephalopathy (PML).Methods:The medical literature was searched for the terms natalizumab and progressive multifocal leukoencephalopathy. A total of 193 international and 34 Italian NTZ-PML cases were included. Clinical outcome was determined by comparing the patients' clinical status at PML diagnosis with status after PML resolution. The effects on survival and clinical outcome of PLEX, sex, age, country, pre-PML Expanded Disability Status Scale score, NTZ infusion number, prior…

A randomized trial comparing tamoxifen therapy vs. tamoxifen prophylaxis in bicalutamide-induced gynecomastia.

2012

BACKGROUND: Tamoxifen (TAM) has been shown to be active against the bicalutamide-induced breast events (BEs) gynecomastia, and breast pain in patients with prostate cancer (PC). Optimal doses and schedules are not yet established. Debate still exists about whether prophylaxis with TAM is more effective than treatment of BEs when diagnosed. The results of a randomized study comparing TAM prophylaxis vs. TAM therapy are presented. METHODS: One hundred seventy-six patients with prostate cancer (PC) who were candidates for bicalutamide monotherapy were randomized to receive TAM 20 mg daily orally within 1 month from the onset of BEs (arm A) vs. TAM 10 mg daily starting simultaneously with bical…

Radiographic Investigation of Location and Angulation of Curvatures in Human Maxillary Incisors

2008

The aim of this radiographic study was to evaluate the degree and location of root canal curvatures of human maxillary incisors. A total of 286 extracted human maxillary incisors (145 central and 141 lateral incisors) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. For this in vitro study, the teeth were fixed in a special device and digitally x-rayed with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvature and the according angle were recorded. The results were analyzed descriptively, and p values were calculated with the Wilcoxon Mann-Whitney test. The …