Search results for "multivariate"
showing 10 items of 1520 documents
Adverse events as potential predictive factors of activity in patients with advanced hepatocellular carcinoma treated with lenvatinib
2021
Background and Aim: Lenvatinib is a standard of care option in first-line therapy of advanced hepatocellular carcinoma (HCC). In the present study, we aim to identify, in patients with HCC treated with lenvatinib, a possible association between occurrence and grading of adverse events (AEs) and outcome. Methods: We performed a retrospective analysis of 606 Japanese and Italian patients treated with lenvatinib in first-line setting and investigated the possible correlation between the onset of AEs, toxicity grade (G) and outcome measures such as overall survival (OS) and progression-free survival (PFS). Results: The appearance of arterial hypertension G ≥ 2 independently predicted prolonged …
Kullback-Leibler distance as a measure of the information filtered from multivariate data
2007
We show that the Kullback-Leibler distance is a good measure of the statistical uncertainty of correlation matrices estimated by using a finite set of data. For correlation matrices of multivariate Gaussian variables we analytically determine the expected values of the Kullback-Leibler distance of a sample correlation matrix from a reference model and we show that the expected values are known also when the specific model is unknown. We propose to make use of the Kullback-Leibler distance to estimate the information extracted from a correlation matrix by correlation filtering procedures. We also show how to use this distance to measure the stability of filtering procedures with respect to s…
Are better young readers more likely to confuse their mother with their mohter?
2021
One of the most replicated effects in the contemporary word recognition literature is the transposed-letter effect (TL effect): pseudowords created by the transposition of two letters (e.g., MOHTER) are often misread as the real word. This effect ruled out those accounts that assume that letter position is encoded accurately and led to more flexible coding schemes. Here, we examined whether reading skill modulates this effect. The relationship between reading skill and the TL effect magnitude is a contentious issue both empirically and theoretically. The present lexical decision experiment was designed to shed some light on the relationship between reading skill and the TL effect magnitude…
Identification of Volatile Compounds in Blackcurrant Berries: Differences Among Cultivars
2021
Berries of blackcurrant are known to produce a strong flavor. Some previous studies have reported that a given cultivar of blackcurrant can produce berries with a specific profile of volatile compounds. For the Burgundy region in France, the Noir de Bourgogne cultivar is especially important because it is the main ingredient of a liquor with a designation of origin. The aim of the present study was to characterize the volatile fractions of berries from 15 cultivars in order to explore the possibility of using different cultivars for liquor production. The plants were cultivated under the same conditions and harvested in the same year. The volatile fractions of the harvested berries were ana…
Combining Real-Time Segmentation and Classification of Rehabilitation Exercises with LSTM Networks and Pointwise Boosting
2020
Autonomous biofeedback tools in support of rehabilitation patients are commonly built as multi-tier pipelines, where a segmentation algorithm is first responsible for isolating motion primitives, and then classification can be performed on each primitive. In this paper, we present a novel segmentation technique that integrates on-the-fly qualitative classification of physical movements in the process. We adopt Long Short-Term Memory (LSTM) networks to model the temporal patterns of a streaming multivariate time series, obtained by sampling acceleration and angular velocity of the limb in motion, and then we aggregate the pointwise predictions of each isolated movement using different boosti…
A Multisite-Multipollutant Air Quality Index
2013
Abstract In this paper, starting from a multivariate spatio-temporal array, containing air pollution data collected for the main pollutants at different monitoring sites over a 1-year period, a new approach is proposed to get a Multipollutant-Multisite Air Quality Index (AQI) time series. A two steps aggregation, related to space and to pollutants, is considered. For the first aggregation (spatial synthesis) a PCA is performed on data array opportunely rearranged, while the index I2, proposed in Ruggieri and Plaia (2011) , is used for the second aggregation (pollutant synthesis), obtaining the new index I 2 MS . Daily data of four air pollutants from the city of Palermo (Italy) are analyzed…
An Ecological Study to Investigate Links Between Atmospheric Pollutants From Farming and SARS-CoV-2 Mortality
2021
AbstractExposure to atmospheric particulate matter and nitrogen dioxide has been linked to SARS-CoV-2 infection and death. We hypothesized that an interaction between SARS-CoV-2 infection and exposure to farming-related atmospheric pollutants worsens the effect of SARS-CoV-2 on mortality. Our objective was investigate this hypothesis by performing an ecological study in five Italian Regions (Piedmont, Lombardy, Veneto, Emilia-Romagna and Sicily) linking all-cause mortality, by province (administrative entities within regions), to atmospheric particulate matter (PM2.5and PM10) nitrous oxide (N2O), ammonia (NH3) and methane (CH4) mainly produced by agricultural activities. Study outcome was c…
Multivariate analysis of historical data (2004-2013) in assessing the possible environmental impact of the Bellolampo landfill (Palermo).
2017
Multivariate analysis was performed on a large data set of groundwater and leachate samples collected during 9 years of operation of the Bellolampo municipal solid waste landfill (located above Palermo, Italy). The aim was to obtain the most likely correlations among the data. The analysis results are presented. Groundwater samples were collected in the period 2004–2013, whereas the leachate analysis refers to the period 2006–2013. For groundwater, statistical data evaluation revealed notable differences among the samples taken from the numerous wells located around the landfill. Characteristic parameters revealed by principal component analysis (PCA) were more deeply investigated, and corr…
Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations
2015
This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable)
On Inverse Distance Weighting in Pollution Models
2011
When evaluating the impact of pollution, measurements from remote stations are often weighted by the inverse of distance raised to some nonnegative power (IDW). This is derived from Shepard's method of spatial interpolation (1968). The paper discusses the arbitrary character of the exponent of distance and the problem of monitoring stations that are close to the reference point. From elementary laws of physics, it is determined which exponent of distance should be chosen (or its upper bound) depending on the form of pollution encountered, such as radiant pollution (including radioactivity and sound), air pollution (plumes, puffs, and motionless clouds by using the classical Gaussian model),…