97 research outputs found
Analisi ecologica dei flebotomi vettori della leishmaniosi canina in Italia nord-orientale attraverso l'utilizzo di Sistemi Informativi Geografici (GIS) e Modelli di Distribuzione di Specie
Since the 1990s, new foci of Canine Leishmaniosis have being detected in northern Italy, previously regarded as non-endemic. The disease has increased gradually in the regions of the Alps and entomological surveys demonstrated the established presence of two vectors of the disease, P. perniciosus and P. neglectus, in several localities of the area. The changing pattern of the disease is mainly due to movement of infected dogs from endemic areas, to the increase in human and animal travels and goods trade and to climatic changes, critical to the establishment of the vectors.
The study describes the results of the 12-years entomological survey in Veneto, Friuli Venezia Giulia and Trentino Alto Adige Regions, analysed through the use of GIS tools and Species Distribution Models (SDMs), based on remote sensing environmental data. Several climatic and environmental features were explored in regard to the entomological data, in order to better understand the ecology of the vectors and the epidemiology of the disease, to create a tool in support of surveillance activities.
Sandfly trapping was conducted from 2001 to 2012 in 175 sites, using sticky traps (n=114 sites), CDC light traps (n=53) and CO2 traps (n=66). GPS coordinates were acquired for all sites and potential risk factors (altitude, number and species of domestic bait animals, structural characteristics of site and level of urbanization) were identified and registered. The presence/absence of sandflies were compared with the risk factors considered and environmental variables, such as MODIS data (Normalized Difference Vegetation Index and Land Surface Temperature), a land cover map (Corine Land Cover 2006), a Digital Elevation Model (GTOPO30) and a bioclimatic variable taken from the database WorldClim (BIO 18, precipitation of Warmest Quarter). The environmental features resulted more relevant, were used to built a predictive model of presence of P. perniciosus and sandflies in Veneto, Friuli Venezia Giulia and Trentino Alto Adige Regions, using the software MaxEnt (Maximum Entropy Modeling System).
Overall, 6.144 sandflies were collected and identified and P. perniciosus was the most abundant species (3.797, 61,8%), with density values comparable to endemic areas of southern and central Italy. The ecological analyses of risk factors identified the altitudinal range between 100 and 300 m as the optimal environment for sandflies. The analyses of eco-climatic variables showed that the species P. perniciosus and the sandflies prefer hilly areas, characterized by temperate climate, high vegetation cover and moderate rainfall.
The SDMs developed showed a high predictive power and demonstrated to be realistic, since areas highly suitable for sandflies overlap with Canine Leishmaniosis foci in the study area.
Visualisation of patterns of distribution of vector species in ecological space, using SDMs, was a useful tool for the understanding of the ecological requirements of the sandfly vectors. The used approach may be considered a new resource for the proper identification of the surveillance actions for the control of Canine Leishmaniosis
The Forgotten Role of Central Volume in Low Frequency Oscillations of Heart Rate Variability
The hypothesis that central volume plays a key role in the source of low frequency (LF) oscillations of heart rate variability (HRV) was tested in a population of end stage renal disease patients undergoing conventional hemodialysis (HD) treatment, and thus subject to large fluid shifts and sympathetic activation. Fluid overload (FO) in 58 chronic HD patients was assessed by whole body bioimpedance measurements before the midweek HD session. Heart Rate Variability (HRV) was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. Time domain and frequency domain analyses were performed on HRV signals. Patients were retrospectively classified in three groups according to tertiles of FO normalized to the extracellular water (FO/ECW%). These groups were also compared after stratification by diabetes mellitus. Patients with the low to medium hydration status before the treatment (i.e. 1st and 2nd FO/ECW% tertiles) showed a significant increase in LF power during last 30 min of HD compared to dialysis begin, while no significant change in LF power was seen in the third group (i.e. those with high pre-treatment hydration values). In conclusion, several mechanisms can generate LF oscillations in the cardiovascular system, including baroreflex feedback loops and central oscillators. However, the current results emphasize the role played by the central volume in determining the power of LF oscillations
Towards improved, cost-effective surveillance of Ixodes ricinus ticks and associated pathogens using species distribution modelling
Various ticks exist in the temperate hilly and pre-alpine areas of Northern Italy, where Ixodes ricinus is the more important. In this area different tick-borne pathogen monitoring projects have recently been implemented; we present here the results of a twoyear field survey of ticks and associated pathogens, conducted 2009-2010 in North-eastern Italy. The cost-effectiveness of different sampling strategies, hypothesized a posteriori based on two sub-sets of data, were compared and analysed. The same two subsets were also used to develop models of habitat suitability, using a maximum entropy algorithm based on remotely sensed data. Comparison of the two strategies (in terms of number of ticks collected, rates of pathogen detection and model accuracy) indicated that monitoring at many temporary sites was more cost-effective than monthly samplings at a few permanent sites. The two model predictions were similar and provided a greater understanding of ecological requirements of I. ricinus in the study area. Dense vegetation cover, as measured by the normalized difference vegetation index, was identified as a good predictor of tick presence, whereas high summer temperatures appeared to be a limiting factor. The study suggests that it is possible to obtain realistic results (in terms of pathogens detection and development of habitat suitability maps) with a relatively limited sampling effort and a wellplanned monitoring strategy
Effects of fluid overload on heart rate variability in chronic kidney disease patients on hemodialysis
BACKGROUND: While fluid overload (FO) and alterations in the autonomic nervous system (ANS) such as hypersympathetic activity, are known risk factors for cardiovascular morbidity and mortality in patients on chronic hemodialysis (HD), their relationship has not been thoroughly studied. METHODS: In this observational study involving 69 patients on chronic HD, FO was assessed by whole body bioimpedance measurements before the midweek HD session and ANS activity reflected by Heart Rate Variability (HRV) was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. In total, 13 different HRV indices were analyzed, comprising a mixture of time domain, frequency domain and complexity parameters. A correlation analysis was performed between the HRV indices and hydration status indices. Successively, patients were retrospectively assigned to a high FO (H, FO > 2.5 L) or low FO (L, FO ≤ 2.5 L) group and these were further compared also after stratification by diabetes mellitus. Finally, a small number of patients without diabetes with significant and persistent FO were followed up for 3 months post-study to investigate how normalization of fluid status affects HRV. RESULTS: SDANN, VLF, LZC and HF% parameters significantly correlate with FO (correlation coefficients were respectively r = –0.40, r = –0.37, r = –0.28 and r = 0.26, p-value < 0.05). Furthermore, LF% and LF/HF were inversely correlated with hydration status (correlation coefficients were respectively r = –0.31 and r = -0.33, p-value < 0.05). These results indicate an association between FO and reduced HRV, higher parasympathetic activation and reduced sympathetic response to the HD session. Indeed, group H tended to have lower values of SDANN, VLF and LZC, and higher values of HF% than patients in the L group. Finally, there was a trend towards lower LF% measured during the last 30 minutes of HD for the H group versus the L group. Reduction in FO achieved over 3 months by implementation of a strict fluid management plan resulted in an increase of HRV. CONCLUSIONS: Our results suggest that depressed HRV is associated with fluid overload and that normalization of hydration status is accompanied by improved HRV
Complexity analysis of the fetal heart rate variability: early identification of severe intrauterine growth-restricted fetuses
The main goal of this work is to suggest new indices for a correct identification of the intrauterine growth-restricted (IUGR) fetuses on the basis of fetal heart rate (FHR) variability analysis performed in the antepartum period. To this purpose, we analyzed 59 FHR time series recorded in early periods of gestation through a Hewlett Packard 1351A cardiotocograph. Advanced analysis techniques were adopted including the computation of the Lempel Ziv complexity (LZC) index and the multiscale entropy (MSE), that is, the entropy estimation with a multiscale approach. A multiparametric classifier based on k-mean cluster analysis was also performed to separate pathological and normal fetuses. The results show that the proposed LZC and the MSE could be useful to identify the actual IUGRs and to separate them from the physiological fetuses, providing good values of sensitivity and accuracy (Se = 77.8%, Ac = 82.4%)
Investigation of the molecular mechanisms which contribute to the survival of the polychaete Platynereis spp. under ocean acidification conditions in the CO2 vent system of Ischia Island (Italy)
The continuous increase of CO2 emissions in the atmosphere due to anthropogenic activities is one of the most important factors that contribute to Climate Change and generates the phenomenon known as Ocean Acidification (OA). Research conducted at the CO2 vents of Castello Aragonese (Ischia, Italy), which represents a natural laboratory for the study of OA, demonstrated that some organisms, such as polychaetes, thrive under acidified conditions through different adaptation mechanisms. Some functional and ecological traits promoting tolerance to acidification in these organisms have been identified, while the molecular and physiological mechanisms underlying acclimatisation or genetic adaptation are still largely unknown. Therefore, in this study we investigated epigenetic traits, as histone acetylation and methylation, in Platynereis spp. individuals coming from the Castello vent, and from a nearby control site, in two different periods of the year (November-June). Untargeted metabolomics analysis was also carried out in specimens from the two sites. We found a different profile of acetylation of H2B histone in the control site compared to the vent as a function of the sampling period. Metabolomic analysis showed clear separation in the pattern of metabolites in polychaetes from the control site with respect to those from the Castello vent. Specifically, a significant reduction of lipid/sterols and nucleosides was measured in polychaetes from the vent. Overall results contribute to better understand the potential metabolic pathways involved in the tolerance to OA
Analisi ecologica dei flebotomi vettori della leishmaniosi canina in Italia nord-orientale attraverso l'utilizzo di Sistemi Informativi Geografici (GIS) e Modelli di Distribuzione di Specie
Since the 1990s, new foci of Canine Leishmaniosis have being detected in northern Italy, previously regarded as non-endemic. The disease has increased gradually in the regions of the Alps and entomological surveys demonstrated the established presence of two vectors of the disease, P. perniciosus and P. neglectus, in several localities of the area. The changing pattern of the disease is mainly due to movement of infected dogs from endemic areas, to the increase in human and animal travels and goods trade and to climatic changes, critical to the establishment of the vectors.
The study describes the results of the 12-years entomological survey in Veneto, Friuli Venezia Giulia and Trentino Alto Adige Regions, analysed through the use of GIS tools and Species Distribution Models (SDMs), based on remote sensing environmental data. Several climatic and environmental features were explored in regard to the entomological data, in order to better understand the ecology of the vectors and the epidemiology of the disease, to create a tool in support of surveillance activities.
Sandfly trapping was conducted from 2001 to 2012 in 175 sites, using sticky traps (n=114 sites), CDC light traps (n=53) and CO2 traps (n=66). GPS coordinates were acquired for all sites and potential risk factors (altitude, number and species of domestic bait animals, structural characteristics of site and level of urbanization) were identified and registered. The presence/absence of sandflies were compared with the risk factors considered and environmental variables, such as MODIS data (Normalized Difference Vegetation Index and Land Surface Temperature), a land cover map (Corine Land Cover 2006), a Digital Elevation Model (GTOPO30) and a bioclimatic variable taken from the database WorldClim (BIO 18, precipitation of Warmest Quarter). The environmental features resulted more relevant, were used to built a predictive model of presence of P. perniciosus and sandflies in Veneto, Friuli Venezia Giulia and Trentino Alto Adige Regions, using the software MaxEnt (Maximum Entropy Modeling System).
Overall, 6.144 sandflies were collected and identified and P. perniciosus was the most abundant species (3.797, 61,8%), with density values comparable to endemic areas of southern and central Italy. The ecological analyses of risk factors identified the altitudinal range between 100 and 300 m as the optimal environment for sandflies. The analyses of eco-climatic variables showed that the species P. perniciosus and the sandflies prefer hilly areas, characterized by temperate climate, high vegetation cover and moderate rainfall.
The SDMs developed showed a high predictive power and demonstrated to be realistic, since areas highly suitable for sandflies overlap with Canine Leishmaniosis foci in the study area.
Visualisation of patterns of distribution of vector species in ecological space, using SDMs, was a useful tool for the understanding of the ecological requirements of the sandfly vectors. The used approach may be considered a new resource for the proper identification of the surveillance actions for the control of Canine Leishmaniosis.A partire dagli anni '90, sono stati evidenziati nuovi focolai autoctoni di leishmaniosi canina in Italia settentrionale, area fino agli anni precedenti considerata indenne. Gradualmente, la malattia si è diffusa nelle Regioni dell’arco alpino e i monitoraggi entomologici condotti, hanno evidenziato la presenza stabile di due vettori della malattia, P. perniciosus e P. neglectus, in diverse aree del Territorio. Il cambiamento della distribuzione della malattia sembra legato principalmente al movimento dei cani infetti dalle aree endemiche, all’aumento degli spostamenti di merci, animali e persone ed ai cambiamenti climatici, determinanti per la sopravvivenza dei vettori.
Lo studio descrive i risultati di 12 anni di campionamenti entomologici, condotti in Veneto, Friuli Venezia Giulia e Trentino Alto Adige, analizzati attraverso l’utilizzo di strumenti GIS e modelli di distribuzione di specie (SDMs) basati su dati ambientali ottenuti tramite remote sensing. Sono state analizzate diverse caratteristiche climatiche ed ambientali, relazionandole con i dati relativi ai monitoraggi, con la finalità di comprendere meglio l’ecologia dei vettori e l’epidemiologia della malattia, per creare uno strumento di supporto alle attività di sorveglianza.
Il monitoraggio è stato condotto dal 2001 al 2012 in 175 siti, utilizzando sticky traps (n=114 siti), CDC light traps (n=53 siti) e CO2 traps (n=66 siti). I siti sono stati geo-referenziati ed alcuni possibili fattori di rischio (altitudine, numero e specie di animali esca, tipologia di sito e livello di urbanizzazione) sono stati individuati e registrati sul campo. I dati di presenza/assenza dei flebotomi sono stati analizzati in funzione dei fattori di rischio considerati, di due variabili ambientali ottenute dal sensore MODIS (Normalized Difference Vegetation Index e Land Surface Temperature), di una mappa di uso del suolo (Corine Land Cover 2006), di un modello digitale del terreno (GTOPO30) e di una variabile climatica ottenuta dal data set WorldClim (BIO 18), relativa alle precipitazioni medie registrate nei trimestri più caldi.
Le variabili risultate più rilevanti sono state utilizzate per elaborare un modello predittivo della presenza di P. perniciosus e dei flebotomi in Triveneto, utilizzando il software MaxEnt (Maximum Entropy Modeling System).
In totale sono stati raccolti e identificati 6.144 flebotomi e P. perniciosus si è dimostrato essere la specie più rappresentata nel territorio (3.797 esemplari, 61,8%), con densità paragonabili a quelle registrate nelle aree endemiche del centro-sud Italia. L’analisi ecologica dei fattori di rischio ha individuato la fascia altitudinale tra i 100 e i 300 m s.l.m. come quella più idonea ai flebotomi. L’analisi delle variabili ambientali ha evidenziato che i flebotomi e P. perniciosus prediligono ambienti collinari, caratterizzati da un clima mite, elevata copertura vegetazionale e precipitazioni non abbondanti. Il modello di distribuzione di specie elaborato, ha mostrato un buon potere predittivo e si è dimostrato realistico, in quanto l’area risultata più idonea alla presenza dei flebotomi nel territorio si sovrappone in modo chiaro con le aree interessate da focolai di leishmaniosi canina.
La visualizzazione dei pattern di distribuzione dei flebotomi vettori nello spazio ecologico, attraverso l’utilizzo di modelli di distribuzione di specie, si è dimostrata essere un valido strumento per comprendere quali fattori condizionano maggiormente la presenza degli stessi. Gli strumenti utilizzati possono essere considerati una nuova risorsa da integrare alle azioni di sorveglianza per la prevenzione della leishmaniosi canina, con il fine di destinare le risorse correttamente e di sviluppare strategie sempre più appropriate
Il fenomeno della violenza di genere: azioni di contrasto e ruolo delle istituzioni all’Isola d’Elba e in Toscana
Il presente lavoro di tesi si propone di affrontare ed analizzare il sommerso fenomeno della violenza di genere, con l’obbiettivo di mettere in luce le caratteristiche e le forme con le quali si presenta, con lo scopo quindi di offrire un quadro conoscitivo ed uno spazio di riflessione. Nell’intento di fronteggiare un problema di tale portata emerge la necessità di andare a rintracciare quei fenomeni sociali che innescano la violenza e di conseguenza, mettere in atto azioni di prevenzione, educazione e sostegno alle vittime, per accompagnarle nel percorso di uscita dalla violenza, renderle libere, consapevoli ed indipendenti, il tutto, nell’ottica di un lavoro di rete multidisciplinare attuato da diversi professionisti, con il coinvolgimento e la partecipazione attiva della comunità, con il fine di sviluppare una cultura del rispetto, della non violenza e caratterizzata da un’auspicabile parità di genere
Comparison between fetal heart rate standard parameters and complexity indexes for the identification of severe intra uterine growth restriction
Objectives: The intrauterine growth restriction (IUGR) is a pathological state: the fetus is ot risk of hypoxia and this condition is associated with increased perinatal morbidity and mortality. However, evidence-based guidelines for clinical surveillance are poor and lack reliable indexes. This study introduces new procedures to extract parameters from the fetal heart rate signal in order to identify severe intrauterine growth restricted (IUGR) fetuses Methods: Standard parameters (time domain and frequency domain indexes) are compared to a new parameter, the Lempel Ziv complexity, and to two regularity estimators (approximate entropy and sample entropy). The paper analyzes the robustness of the indexes coming from the parameter extraction procedure. Results and Conclusions: The results show that the LZ complexity is a stable parameter and it is able to significantly discriminate the severe IUGR (preterm delivered) from moderate IUGR (at term delivered) and from healthy fetuses. © 2007 Schattauer GmbH
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