Search results for "Regression"
showing 10 items of 2619 documents
Political risk and export promotion: evidence from Germany
2008
Political risk represents an important hidden transaction cost that reduces international trade. This paper investigates the claim that German public export credit guarantees (Hermes guarantees) mitigate this friction to trade flows and hence promote exports. We employ an empirical trade gravity model, where we explicitly control for political risk in the importing country in order to evaluate the effect of export guarantees. The idea behind export promotion through public export credit agencies (ECAs) is that the private market is unable to provide adequate insurance for all risks associated with exports. As a consequence, firms' export activities are limited in the absence of insurance pr…
Transanal Endoscopic Microsurgery for T1 and T2 Rectal Cancers: A Meta–Analysis and Meta-Regression Analysis of Outcomes
2011
The objective of this study is to assess transanal endoscopic microsurgery (TEM) as a surgical strategy for stage I rectal cancer. The literature lacks level I and level II evidence of the oncologic competence of TEM. Three randomized controlled, one prospective, and seven retrospective comparative studies were evaluated. End-points included perioperative outcomes, margin involvement, disease-free and overall survival, and recurrence. The number of patients with major (odds ratio (OR) = 0.24,95% confidence interval (CI) 0.07–0.91) and overall postoperative complications (OR = 0.16, 95% CI 0.06-0.38) were significantly lower in TEM. The disease-free survival was higher in standard resection…
Finnish salmon resistant to Gyrodactylus salaris: a long-term study at fish farms.
1996
Abstract The occurrence of Gyrodactylus salaris on Baltic salmon ( Salmo salar ), sea trout ( S. trutta m. trutta ) and brown trout ( S. trutta m. lacustris ) was examined from 1984 to 1993 at 4 fish farms (A, B, C and D) that produce smolts for stocking in northern Finland. No G. salaris was found on the sea or brown trout, but it did occur on salmon for 6–7 years at farms B, C and D, the prevalences of infection being 9.5%, 17.7% and 8.8% for salmon yearlings and smolts during that time, respectively, but less than 1.2% for fingerlings at farms B and C. Only brood stock salmon were infected at farm A in 4 years. The abundances of G. salaris increased during the second winter of each year …
Increase in rear-end collision risk by acute stress-induced fatigue in on-road truck driving.
2021
Increasing road crashes related to occupational drivers’ deteriorating health has become a social problem. To prevent road crashes, warnings and predictions of increased crash risk based on drivers’ conditions are important. However, in on-road driving, the relationship between drivers’ physiological condition and crash risk remains unclear due to difficulties in the simultaneous measurement of both. This study aimed to elucidate the relationship between drivers’ physiological condition assessed by autonomic nerve function (ANF) and an indicator of rear-end collision risk in on-road driving. Data from 20 male truck drivers (mean ± SD, 49.0±8.2 years; range, 35–63 years) were analyzed. Over …
From COVID-19 to future electrification: Assessing traffic impacts on air quality by a machine-learning model
2021
The large fluctuations in traffic during the COVID-19 pandemic provide an unparalleled opportunity to assess vehicle emission control efficacy. Here we develop a random-forest regression model, based on the large volume of real-time observational data during COVID-19, to predict surface-level NO(2), O(3), and fine particle concentration in the Los Angeles megacity. Our model exhibits high fidelity in reproducing pollutant concentrations in the Los Angeles Basin and identifies major factors controlling each species. During the strictest lockdown period, traffic reduction led to decreases in NO(2) and particulate matter with aerodynamic diameters <2.5 μm by –30.1% and –17.5%, respectively, bu…
Ranking world tourist destinations with a composite indicator of competitiveness: To weigh or not to weigh?
2019
Abstract This paper contributes a weighted composite indicator of competitiveness for 136 world tourist destinations. To that end, Data Envelopment Analysis and Multi-Criteria-Decision-Making techniques are used with raw indicators from the 2017 edition of the Travel & Tourism Competitiveness Report of the World Economic Forum (WEF). An outstanding feature of our approach is that weights are endogenously generated. Furthermore, the role played by several variables in tourism competitiveness is assessed using truncated regression and bootstrapping. The ranking of world tourist destinations produced by our weighted composite indicator of competitiveness is, however, fairly similar to that der…
Langzeitverlauf 10 Jahre nach transpupillarer Thermotherapie (TTT) kleiner, posteriorer maligner Aderhautmelanome
2011
Background The aim of this study was to evaluate the long-term results of transpupillary thermotherapy (TTT) for small malignant choroidal melanomas. Patients and methods In the time period 1/1998 to 10/1999 in a prospective non-randomised analysis 26 eyes with small malignant melanomas (located posterior to the equator with base ≤ 12 and thickness ≤ 4.5 mm) were primary treated with the TTT standard protocol (follow-up over a time span of at least 10 years). Results Thirteen women and thirteen men (mean age: 64 years) underwent TTT. The mean preoperative tumour thickness was 2.45 mm (0.8 - 4.5 mm). Ten years postoperatively tumour regression without recurrence after 1.4 treatment sessions …
The impact of healthy lifestyles on academic achievement among Italian adolescents
2021
AbstractWe evaluated the association between healthy lifestyles and academic achievement in a sample of 373 adolescent Italian students. Specifically, we investigated on the association between use of illegal drugs, habits to practice a regular physical, typology of diet, levels of social support, levels of self-esteem, level of Internet use, perceived stress and amount of sleep and academic achievement. Academic performance was positively correlated with good diet, perceived social support, and self-esteem. A statistically significant difference emerged between students with high versus low correct grade point averages in relation to lifetime and current use of illegal drugs. Last, academi…
Using the Breeder genetic algorithm to optimize a multiple regression analysis model used in prediction of the mesiodistal width of unerupted teeth
2014
For the prediction of the unerupted canine and premolars mesiodistal size, have been proposed different variants of multiple linear regression equations (MLRE). These are based on the amount of the upper and lower permanent incisors with a tooth of the lateral support. Aim of present study was to develop a method for optimization of MLRE, using a genetic algorithm for determining a set of coefficients that minimizes the prediction error for the sum of permanent premolars and canines dimensions from a group of young people in an area Romania's central city represented by Sibiu. To test the proposed method, we used a multiple linear regression equation derived from the estimation method propo…
258 Helicobacter Pylori Infection in Allergic Children
2010
Background and aims: Studies have suggested that Helicobacter pylori (H.pylori) infection could be considered as a protective factor against development of allergic illnesses. The goal of our study was to compare the prevalence of H. pylori infection in allergic patients and children without allergy. Methods: The total patient sample consisted of 147 children aged 1-10 yrs (mean age 5.2): 58 children had allergy diagnosis and 89 were healthy children or children with minor health problems. Parents were asked to bring a faecal samples of the child and to fill out a questionnaire (demographic data, socio-economical factors). Presence of active H. pylori infection was detected by stool antigen…