Different FDG-PET metabolic patterns at single-subject level in the behavioral variant of fronto-temporal dementia.

BACKGROUND: The diagnosis of probable behavioral variant of fronto-temporal dementia (bvFTD) according to current criteria requires the imaging evidence of frontal and/or anterior temporal atrophy or hypoperfusion/hypometabolism. Different variants of this pattern of brain involvement may, however, be found in individual cases, supporting the presence of heterogeneous phenotypes. OBJECTIVE: We examined in a case-by-case approach the FDG-PET metabolic patterns of patients fulfilling clinical criteria for probable bvFTD, assessing the presence and frequency of specific FDG-PET features. MATERIALS AND METHODS: Fifty two FDG-PET scans of probable bvFTD patients were retrospectively analyzed together with clinical and neuropsychological data. Neuroimaging experts rated the FDG-PET hypometabolism maps obtained at the single-subject level with optimized voxel-based Statistical Parametric Mapping (SPM). The functional metabolic heterogeneity was further tested by hierarchical cluster analysis and principal component analysis (PCA). RESULTS: Both the SPM maps and cluster analysis identified two major variants of cerebral hypometabolism, namely the "frontal" and the "temporo-limbic", which were correlated with different cognitive profiles. Executive and language deficits were the cognitive hallmark in the "frontal" subgroup, while poor encoding and recall on long-term memory tasks was typical of the "temporo-limbic" subgroup. DISCUSSION: SPM single-subject analysis indicates distinct patterns of brain dysfunction in bvFTD, coupled with specific clinical features, suggesting different profiles of neurodegenerative vulnerability. These findings have important implications for the early diagnosis of bvFTD and for the application of the recent international consensus criteria

Measurement of the very rare K+→π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

Soil sealing in Padua and green scenarios: the case study of San Lazzaro district

The increase of soil sealing is presently affecting urban areas by concrete surfaces, asphalt, new buildings, and infrastructures. This phenomenon is eroding important urban ecosystem services provided by the soil system: carbon sequestration, micro-climate regulation, mitigation of hydrogeological risk, water and air purification, cultural and aesthetical services. According to ISPRA (2016) soil sealing in Italy is a crucial issue at national scale, so that 21,100 km2 (7%) are, at present, sealed. Veneto is one of the most affected region showing the highest values in the Province of Padua by 40,310 ha sealed from 2012 (18,8%). The city of Padua is one of the 20 municipalities most affected by this phenomenon, showing 4,558 ha sealed only in 2015. In such context the European Commission is addressing urban policies and strategies to implement adaptation and mitigation measures to compensate soil sealing and improve ecosystem services quality (2016). The general aim of this work is evaluating the evolution of the territory in complex macro-area of Padua (the San Lazzaro neighborhood), characterized by an industrial sector, a residential district, broad communication infrastructures, and green areas

Soil sealing in Padua and green scenarios: the case study of San Lazzaro district

The increase of soil sealing is presently affecting urban areas by concrete surfaces, asphalt, new buildings, and infrastructures. This phenomenon is eroding important urban ecosystem services provided by the soil system: carbon sequestration, micro-climate regulation, mitigation of hydrogeological risk, water and air purification, cultural and aesthetical services. According to ISPRA (2016) soil sealing in Italy is a crucial issue at national scale, so that 21,100 km2 (7%) are, at present, sealed. Veneto is one of the most affected region showing the highest values in the Province of Padua by 40,310 ha sealed from 2012 (18,8%). The city of Padua is one of the 20 municipalities most affected by this phenomenon, showing 4,558 ha sealed only in 2015. In such context the European Commission is addressing urban policies and strategies to implement adaptation and mitigation measures to compensate soil sealing and improve ecosystem services quality (2016). The general aim of this work is evaluating the evolution of the territory in complex macro-area of Padua (the San Lazzaro neighborhood), characterized by an industrial sector, a residential district, broad communication infrastructures, and green areas

COVID-19 ICU mortality prediction: a machine learning approach using SuperLearner algorithm

Background: Since the beginning of coronavirus disease 2019 (COVID-19), the development of predictive models has sparked relevant interest due to the initial lack of knowledge about diagnosis, treatment, and prognosis. The present study aimed at developing a model, through a machine learning approach, to predict intensive care unit (ICU) mortality in COVID-19 patients based on predefined clinical parameters. Results: Observational multicenter cohort study. All COVID-19 adult patients admitted to 25 ICUs belonging to the VENETO ICU network (February 28th 2020-april 4th 2021) were enrolled. Patients admitted to the ICUs before 4th March 2021 were used for model training (“training set”), while patients admitted after the 5th of March 2021 were used for external validation (“test set 1”). A further group of patients (“test set 2”), admitted to the ICU of IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan, was used for external validation. A SuperLearner machine learning algorithm was applied for model development, and both internal and external validation was performed. Clinical variables available for the model were (i) age, gender, sequential organ failure assessment score, Charlson Comorbidity Index score (not adjusted for age), Palliative Performance Score; (ii) need of invasive mechanical ventilation, non-invasive mechanical ventilation, O2 therapy, vasoactive agents, extracorporeal membrane oxygenation, continuous venous-venous hemofiltration, tracheostomy, re-intubation, prone position during ICU stay; and (iii) re-admission in ICU. One thousand two hundred ninety-three (80%) patients were included in the “training set”, while 124 (8%) and 199 (12%) patients were included in the “test set 1” and “test set 2,” respectively. Three different predictive models were developed. Each model included different sets of clinical variables. The three models showed similar predictive performances, with a training balanced accuracy that ranged between 0.72 and 0.90, while the cross-validation performance ranged from 0.75 to 0.85. Age was the leading predictor for all the considered model

Search for heavy neutrinos in K+→μ+νμK^+ \rightarrow \mu^+ \nu_{\mu} decays

International audienceThe NA62 experiment recorded a large sample of K+→μ+νμ decays in 2007. A peak search has been performed in the reconstructed missing mass spectrum. In the absence of a signal, limits in the range 2×10−6 to 10−5 have been set on the squared mixing matrix element |Uμ4|2 between muon and heavy neutrino states, for heavy neutrino masses in the range 300–375 MeV/ c2 . The result extends the range of masses for which upper limits have been set on the value of |Uμ4|2 in previous production search experiments