Search results for "regression"
showing 10 items of 2619 documents
Evaluating the predictive power of sun-induced chlorophyll fluorescence to estimate net photosynthesis of vegetation canopies: A SCOPE modeling study
2016
Abstract Progress in imaging spectroscopy technology and data processing can enable derivation of the complete sun-induced chlorophyll fluorescence (SIF) emission spectrum. This opens up opportunities to fully exploit the use of the SIF spectrum as an indicator of photosynthetic activity. Simulations performed with the coupled fluorescence–photosynthesis model SCOPE were used to determine how strongly canopy-leaving SIF can be related to net photosynthesis of the canopy (NPC) for various canopy configurations. Regression analysis between SIF retrievals and NPC values produced the following general findings: (1) individual SIF bands that were most sensitive to NPC were located around the fir…
A global Canopy Water Content product from AVHRR/Metop
2020
Abstract Spatially and temporally explicit canopy water content (CWC) data are important for monitoring vegetation status, and constitute essential information for studying ecosystem-climate interactions. Despite many efforts there is currently no operational CWC product available to users. In the context of the Satellite Application Facility for Land Surface Analysis (LSA-SAF), we have developed an algorithm to produce a global dataset of CWC based on data from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board Meteorological–Operational (MetOp) satellites forming the EUMETSAT Polar System (EPS). CWC reflects the water conditions at the leaf level and information related …
Foreign Direct Investment Drivers in Romania
2013
Foreign Direct Investment (FDI) represents a condition sine qua non for a sustainable development of Romania, taking into consideration the fact that the domestic capital is not enough to assure a positive and significant growth. The present study uses the multiple linear regression to determine the main factors which influence FDI level in Romania. The international reserve and the capital market index BET have a direct and positive impact on the foreign investment flow, while the short, medium and long private and public external debt proved to influence direct, but in a negative way, the FDI.
Evaluation of nutritional parameters in infant formulas and powdered milk by Raman spectroscopy
2007
It has been made a critical evaluation of the application of near infrared Fourier transform-Raman spectroscopy for the simultaneous determination of the most important nutritional parameters such as energetic value, carbohydrate, protein and fat contents of infant formula and powdered milk samples based on the use of partial least squares (PLS) regression analysis. A highly heterogeneous population of 23 samples, covering a wide range of infant food formula and powdered milk, were obtained from the Spanish market. Raman spectra, obtained by excitation with a Nd:YAG laser at 1064 nm, show no disturbing fluorescence effects; therefore sample spectra can be recorded without any previous prepa…
Factors Influencing Soil Organic Carbon Stock Variations in Italy During the Last Three Decades
2010
Soils contain about three times the amount of carbon globally available in vegetation, and about twice the amount in the atmosphere. However, soil organic carbon (SOC) has been reduced in many areas, while an increase in atmospheric CO2 has been detected. Recent research works have shown that it is likely that past changes in land use history and land management were the main reasons for the loss of carbon rather than higher temperatures and changes of precipitation resulting from climate change. The primary scope of this work was to estimate soil organic carbon stock (CS) variations in Italy during the last three decades and to relate them to land use changes. The study was also aimed at f…
Carotid restenosis is associated with plasma ADMA concentrations in carotid endarterectomy patients
2011
Abstract Background: The aim of this work has been to study the association between plasma asymmetric dimethylarginine (ADMA) concentrations and carotid stenosis in a group of 64 patients undergoing carotid endarterectomy (CEA). Methods: Arginine, ADMA and symmetric dimethylarginine (SDMA) were measured using capillary electrophoresis with UV detection. An evaluation of plasma concentrations of total cysteine (tCys) and total homocysteine (tHcy) was also performed. Results: Pearson’s analysis show a positive correlation between ADMA and carotid stenosis (r=0.37, p=0.003), which is also confirmed after stepwise multiple linear regression analysis. ADMA plasma concentrations were significantl…
Fish population size, and not density, as the determining factor of parasite infection: a case study.
2004
The diversity and abundance of parasites vary widely among populations of the same host species. These infection parameters are, to some extent, determined by characteristics of the host population or of its habitat. Recent studies have supported predictions derived from epidemiological models regarding the influence of host population density: parasite abundance and parasite species richness are expected to increase with increasing host population density, at least for directly transmitted parasites. Here, we test this prediction using a natural system in which populations of the crucian carp, Carassius carassius (L.), occur alone, with no other fish species, in a series of 9 isolated pond…
Consumer attitude toward using smart shopping carts: a comparative analysis of Italian and Croatian consumer attitudes
2016
This paper aims to explore consumer attitudes toward using smart shopping cart, considering country of origin, gender, age, and intentions to use smart shopping carts while purchasing. Moreover, it investigates the influence of extracted factors on consumers' attitudes toward using smart shopping carts and the users' levels of digital competence. The data was collected through survey questionnaires using a purposive sample of 313 Croatian and Italian respondents. To this end, we applied statistical methodologies such as binary logistic regression, factor analysis, and analysis of variance. We found that, compared with Croatians, Italian respondents have a more positive attitude toward using…
Heterozygote Advantage Probably Maintains Rhesus Factor Blood Group Polymorphism: Ecological Regression Study
2016
Rhesus factor polymorphism has been an evolutionary enigma since its discovery in 1939. Carriers of the rarer allele should be eliminated by selection against Rhesus positive children born to Rhesus negative mothers. Here I used an ecologic regression study to test the hypothesis that Rhesus factor polymorphism is stabilized by heterozygote advantage. The study was performed in 65 countries for which the frequencies of RhD phenotypes and specific disease burden data were available. I performed multiple multivariate covariance analysis with five potential confounding variables: GDP, latitude (distance from the equator), humidity, medical care expenditure per capita and frequencies of smokers…
Influence of the chemical composition of monolithic zirconia on its optical and mechanical properties. Systematic review and meta-regression.
2021
Este artículo se encuentra disponible en la siguiente URL: https://www.jstage.jst.go.jp/article/jpr/66/2/66_JPR_D_20_00218/_pdf/-char/en Este artículo de investigación pertenece al número especial "Advances in Personalized Nursing Care". Purpose: This systematic review set out to investigate the influence of chemical composition and specimen thickness of monolithic zirconia on its optical and mechanical properties. Meta-analysis and meta-regression analyzed the effects of variations in percentages of yttrium, aluminum, and specimen thickness of monolithic zirconia. Study selection: The review followed recommendations put forward in the PRISMA checklist. An electronic search for relevant art…