Item selection by Latent Class-based methods

The evaluation of nursing homes is usually based on the administration of questionnaires made of a large number of polytomous items. In such a context, the Latent Class (LC) model represents a useful tool for clustering subjects in homogenous groups corresponding to different degrees of impairment of the health conditions. It is known that the performance of model-based clustering and the accuracy of the choice of the number of latent classes may be affected by the presence of irrelevant or noise variables. In this paper, we show the application of an item selection algorithm to real data collected within a project, named ULISSE, on the quality-of-life of elderly patients hosted in italian nursing homes. This algorithm, which is closely related to that proposed by Dean and Raftery in 2010, is aimed at finding the subset of items which provides the best clustering according to the Bayesian Information Criterion. At the same time, it allows us to select the optimal number of latent classes. Given the complexity of the ULISSE study, we perform a validation of the results by means of a sensitivity analysis to different specifications of the initial subset of items and of a resampling procedure

The role of social identification and hedonism in affecting tourist re-patronizing behaviours: The case of an Italian festival

Since the 1990s Europe and other continents have been organising a significantly larger number of festivals with the objective of stimulating tourism and exploiting potential economic opportunities. The prominence of these events has led to intense competition between festivals in attracting visitors and it has become important to analyse factors which might influence attendees’ retention. Drawing on existing literature on retail and service sectors, this study aims to identify the role played by emotions, hedonism, satisfaction, and social identification in mediating the effects of environmental factors on attendees’ re-patronizing intention. This study includes an on-site survey of 449 visitors attending an Italian festival gaining in popularity, and analyses data using a structural equations model. Results suggest that hedonism and social identification are key-facilitators between environmental cues and attendees’ re-patronizing intention

Gcn5 histone acetyltransferase is present in the mitoplasts

In Saccharomyces cerevisiae the Lysine-acetyltransferase Gcn5 (KAT2) is part of the SAGA complex and is responsible for histone acetylation widely or at specific lysines. In this paper we report that GCN5 deletion differently affects the growth of two strains. The defective mitochondrial phenotype is related to a marked decrease in mtDNA content, which also involves the deletion of specific regions of the molecule. We also show that in wild-type mitochondria the Gcn5 protein is present in the mitoplasts, suggesting a new mitochondrial function independent from the SAGA complex and possibly a new function for this protein connecting epigenetics and metabolism

Sinergia di processi chimico-fisici per la riqualificazione di acque contaminate da composti organici

L’acqua è una delle risorse critiche del pianeta e l’acqua dolce accessibile all’uomo rappresenta meno dell’1% delle risorse idriche; da questi numeri si capisce quanto siano importanti la prevenzione dell’inquinamento ambientale e i processi di depurazione delle acque reflue. A partire dagli anni ’70, grazie anche al miglioramento delle tecniche analitiche, sono iniziati monitoraggi degli inquinanti nelle acque superficiali e sotterranee e sono state riscontrate concentrazioni di inquinanti, i cui effetti di tossicità cronica sull’uomo e l’ecosistema non sempre sono trascurabili. Inoltre si è rilevato che alcune molecole di sintesi sono difficilmente biodegradabili e non sono mineralizzate con i trattamenti convenzionali di depurazione; perciò l’Unione Europea ha emanato delle direttive per preservare le risorse idriche in cui è contenuto un elenco di sostanze prioritarie, per le quali sono stati fissati gli standard di qualità ambientale. Nel 2013 è stata anche istituita una watch list che contiene dieci sostanze sulle quali raccogliere dati di monitoraggio ambientale e effetti sugli ecosistemi. Di qui la ricerca costante di nuovi trattamenti di depurazione delle acque, tra i quali i processi di ossidazione avanzata attirano molto interesse perché promettono di mineralizzare i composti bio-recalcitranti senza produrre fanghi da smaltire o sottoprodotti pericolosi. Oggetto della presente tesi sperimentale, svolta presso il Consiglio Nazionale delle Ricerche, nell’Istituto per la Sintesi Organica e la Fotoreattività, è stato lo studio della de-gradazione e mineralizzazione di una miscela di cinque molecole (diclofenac, carbama-zepina, triton X-100, benzofenone-3, benzofenone-4), scelte per le diverse caratteristiche chimico-fisiche, utilizzando radiazione ultravioletta e ultrasuoni, in presenza di biossido di titanio come fotocatalizzatore o perossido d'idrogeno come additivo per produrre radicali idrossile e avviare catene di reazioni ossidative. A partire dai fenomeni fotochimici o fotocatalitici così ottenuti, eventualmente assistiti da ultrasuoni, sono stati studiati gli effetti delle variazioni dei parametri operativi sulla degradazione dei componenti della miscela e sono stati valutati i consumi energetici della strumentazione prototipale per unità di massa del contaminante degradato. La parte sperimentale è stata preceduta da un’accurata ricerca bibliografica riguardo gli effetti di tossicità degli inquinanti ritrovati nelle acque, la legislazione europea ed italiana in materia ambientale e delle acque e i processi di ossidazione avanzata

A model based in the radius of vesicles to predict the number of unilamellar liposomes

In particulate systems such as liposomes, concentration units are not enough to describe the drug distribution, as suspensions are not homogeneous. In certain in vitro assays, exposure to different number of particles introduces an extra variable regarding to contact phenomena. the aim is to achieve a rapid estimation of the number of unilamellar liposomes in a suspension. A simple mathematical method was developed; variables were the area and molecular weight of lipids, and the mean size of the liposomes. Unilamellar liposomes were prepared. Size was determined by dynamic light scattering, and then the number of particles were determined by tunable resistive pulse sensing. there was about a 90% coincidence between the theoretical results and the number of counted liposomes. This model could be useful for interpretation of in vitro experiments, when results could depend on the distribution of actives into different quantities of liposomes.Fil: Martinetti Montanari, Jorge Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Bucci, Paula Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Alonso, Silvia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; Argentin

Psychometric properties of the Jefferson Scale of Empathy-Health Professional Student's version: an Italian validation study with nursing students.

This methodological study was conducted to test the psychometric properties of the Jefferson Scale of Empathy - Health Professional Student's version (JSE-HPS). It used a convenience sample of 797 Italian nursing students and also aimed to describe their empathic engagement. Data were subjected to exploratory and confirmatory factor analysis, test-retest, correlation analysis, t-test, and analysis of variance method. Principal component factor extraction with Oblimin rotation on the first half of the sample was conducted. The analysis suggested a three-factor solution for 14 items: compassionate care/emotional engagement, perspective-taking, and standing in the patient's shoes. Confirmatory factor analysis on the second half of the sample showed good fit indexes for the 14-item solution, indicated by the exploratory factor analysis, and the 20 item solution of the scale, with the exception of one item. Test-retest correlation was 0.50 (P < -0.001) for the overall scale. Results from group comparisons and correlations are also provided and discussed. The Italian version of the JSE-HPS is a psychometrically sound tool. The translated 20-item solution is also suitable to carry out cross-cultural comparisons

Item selection by an extended Latent Class model: An application to nursing homes evaluation

The evaluation of nursing homes and the assessment of the quality of the health care provided to their patients are usually based on the administration of questionnaires made of a large number of polytomous items. In applications involving data collected by questionnaires of this type, the Latent Class (LC) model represents a useful tool for classifying subjects in homogenous groups. In this paper, we propose an algorithm for item selection, which is based on the LC model. The proposed algorithm is aimed at finding the smallest subset of items which provides an amount of information close to that of the initial set. The method sequentially eliminates the items that do not significantly change the classification of the subjects in the sample with respect to the classification based on the full set of items. The LC model, and then the item selection algorithm, may be also used with missing responses that are dealt with assuming a form of latent ignorability. The potentialities of the proposed approach are illustrated through an application to a nursing home dataset collected within the ULISSE project, which concerns the quality-of-life of elderly patients hosted in Italian nursing homes. The dataset presents several issues, such as missing responses and a very large number of items included in the questionnaire

Item selection by an extended Latent Class model: An application to nursing homes evaluation

The evaluation of nursing homes and the assessment of the quality of the health care provided to their patients are usually based on the administration of questionnaires made of a large number of polytomous items. In applications involving data collected by questionnaires of this type, the Latent Class (LC) model represents a useful tool for classifying subjects in homogenous groups. In this paper, we propose an algorithm for item selection, which is based on the LC model. The proposed algorithm is aimed at finding the smallest subset of items which provides an amount of information close to that of the initial set. The method sequentially eliminates the items that do not significantly change the classification of the subjects in the sample with respect to the classification based on the full set of items. The LC model, and then the item selection algorithm, may be also used with missing responses that are dealt with assuming a form of latent ignorability. The potentialities of the proposed approach are illustrated through an application to a nursing home dataset collected within the ULISSE project, which concerns the quality-of-life of elderly patients hosted in Italian nursing homes. The dataset presents several issues, such as missing responses and a very large number of items included in the questionnaire

Survival, growth, and biogenic amine production of Enterococcus faecium FC12 in response to extracts and essential oils of Rubus fruticosus and Juniperus oxycedrus

Enterococci are lactic acid bacteria (LAB) usually found as food contaminants in fermented products such as cheeses and fermented sausages. Due to their antibiotic resistance, the presence of virulence factors, and the ability to produce biogenic amines (BAs), the determination of these bacteria is crucial to assure food quality and safety. BAs production and consequent accumulation in foods can cause toxicological eects on human health. Plant phenolic compounds are promising alternatives to chemical preservatives and reflect consumers’ demand for “green” solutions. In this study, the antimicrobial eect of blackberry (Rubus fruticosus) leaves and prickly juniper (Juniperus oxycedrus) needles, both as phenolic extracts (PE) and essential oils (EO), were evaluated against Enterococcus faecium FC12, a known tyramine-producing strai