Search results for "Regression Analysis"
showing 10 items of 807 documents
Quaternary diversification in European alpine plants: pattern and process
2004
Molecular clock approaches applied previously to European alpine plants suggest that Primula sect. Auricula , Gentiana sect. Ciminalis and Soldanella diversified at the beginning of the Quaternary or well within this period, whereas Globularia had already started diversifying in the (Late–)Tertiary. In the first part of this paper we present evidence that, in contrast to Globularia and Soldanella , the branching patterns of the molecular internal transcribed spacer phylogenies of both Primula and Gentiana are incompatible with a constant–rates birth–death model. In both of these last two taxa, speciation probably decreased through Quaternary times, perhaps because of some niche–filling pro…
Global retention models and their application to the prediction of chromatographic fingerprints
2020
Abstract The resolution of samples containing unknown compounds of different nature, or without standards available, as is the case of chromatographic fingerprints, is still a challenge. Possibly, the most problematic aspect that prevents systematic method development is finding models that describe without bias the retention behaviour of the compounds in the samples. In this work, the use of global models (able to describe the whole sample) is proposed as an alternative to the use of individual models for each solute. Global models contain parameters that are specific for each solute, while other parameters ‒related to the column and solvent‒ are common for all solutes. A special regressio…
Methane oxidation at a surface-sealed boreal landfill.
2009
Abstract Methane oxidation was studied at a closed boreal landfill (area 3.9 ha, amount of deposited waste 200,000 tonnes) equipped with a passive gas collection and distribution system and a methane oxidative top soil cover integrated in a European Union landfill directive-compliant, multilayer final cover. Gas wells and distribution pipes with valves were installed to direct landfill gas through the water impermeable layer into the top soil cover. Mean methane emissions at the 25 measuring points at four measurement times (October 2005–June 2006) were 0.86–6.2 m 3 ha −1 h −1 . Conservative estimates indicated that at least 25% of the methane flux entering the soil cover at the measuring…
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 …
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…
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…
Satisfaction with the clinical practice among nursing students using regression models and qualitative comparative analysis
2020
Abstract Background Clinical practice is considered fundamental in nursing studies for the effective education of nurses and students' satisfaction. Both the clinical environment and the clinical educator are key factors in students´ satisfaction. Objectives To analyze the influence of the socio-demographic variables of clinical educators and nursing students on satisfaction with the clinical practice. Design This was an observational, cross-sectional study. Settings A clinical practice course at a private university in Valencia, Spain. Participants The study included 527 nursing students enrolled on the clinical practice, supervised by 187 clinical educators. Methods Two statistical method…
Relationship between Perception and Socio-Economic Characteristics of Culture Community in the Development of Marine Ecotourism in Nusmapi Island
2021
Marine tourism is a type of special interest tourism, namely by managing and utilizing marine and coastal landscapes, both those that are managed directly such as swimming, boating, snorkeling, diving, or indirectly such as picnics and beach sports. Nusmapi Island has the potential to be developed as a marine tourism object which has the potential for waters and coral reefs that are in good condition. The purpose of this study was to determine the relationship between the level of public perception and the socio-economic conditions of the local community on Nusmapi Island. In October-November 2020 this research was carried out on Nusmapi Island, Manokwari Regency. The descriptive explorator…