A Multiple Imputation Strategy for Eddy Covariance Data

Half-hourly time series of net ecosystem exchange (NEE) of CO2, latent heat flux (LE) and sensible heat flux (H) measured through the micro-meteorological eddy covariance (EC) technique are noisy and show a high percentage of missing data. By using EC measurements that are part of the FLUXNET2015 dataset, we evaluate the performance of a multiple imputation (MI) strategy based on an efficient computational strategy introduced in Honaker and King (2010), combining the classic Expectation-Maximization (EM) algorithm with a bootstrap approach, in order to take draws from a suitable approximation of posterior distribution of model parameters. Armed with these instruments, we are able to introduce three new multiple imputation models, characterized by an increasing level of complexity, and built on top of multivariate normality assumption: 1) MLR, which imputes EC missing values using a static multiple linear regression of observed values of suitable input variables; 2) ADL, which enriches with dynamic properties the static specification of MLR, by considering an autoregressive distributed lag specification; 3) PADL, which adds further complexity by embedding the ADL model in a panel-data perspective. Under several artificial gap scenarios, we show that PADL has a better ability in modeling the complex dynamics of ecosystem fluxes and reconstructing missing data points, thus providing unbiased imputations and preserving the original sampling distribution. The added flexibility arising from the time series cross section structure of PADL warrants improved performances, outperforming those of other imputation methods, as well as of the marginal distribution sampling algorithm (MDS), a widely used gap- filling approach introduced by Reichstein et al. (2005), especially in the case of nighttime flux data. It is expected that the strategy proposed in this paper will become useful in creating multiple imputations for a variety of EC datasets, providing valid inferences for a broad range of scientific estimands (such as annual budgets)

Transplanting Credibility into a Foreign Voice. An Experiment on Synthesized L2 Italian

This study intends to verify through perceptual tests conducted on original and artificially modified speech whether a relationship exists among the degree of comprehensibility of an utterance, the foreign accent and the credibility of the message. Four bizarre-but-true news read in Italian by four non-native speakers were artificially modified with Praat and WaveSurfer. Each piece of news was transplanted, so that segmental and prosodic features of a text read by a native speaker were transferred onto the same text uttered by a non-native speaker. The corpus was administered to 265 native Italian listeners, who were requested to indicate the degree of comprehensibility, the level of foreign accent and the truthfulness of each item. The results point out the existence of a close inverse relationship between comprehensibility and credibility. The presence of foreign accent, providing an impediment to the understanding of the message, tends to create an attitude of distrust in the listener. The most important features for the foreign accent reduction are the suprasegmental ones and, in particular, the durations of the phones and the pitch movement

The Uncovered Role of Immune Cells and NK Cells in the Regulation of Bone Metastasis

Bone is one of the main metastatic sites of solid tumors like breast, lung, and prostate cancer. Disseminated tumor cells (DTCs) and cancer stem cells (CSCs) represent the main target to counteract bone metastatization. These cells often localize in bone marrow (BM) at level of pre-metastatic niche: they can remain dormant for years or directly grow and create bone lesion, according to the different stimulations received in BM. The immune system in bone marrow is dampened and represents an appealing site for DTCs/CSCs. NK cells have an important role in controlling tumor progression, but their involvement in bone metastasis formation is an interesting and not fully investigated issue. Indeed, whether NK cells can interfere with CSC formation, kill them at the site of primary tumor, during circulation or in the pre-metastic niche needs to be elucidated. This review focuses on different aspects that regulate DTC/CSC life in bone and how NK cells potentially control bone metastasis formation

The Logic of Probability: A Trip through Uncertainty

In real life we have to deal with uncertainty, imprecision and vagueness. Many ideas were introduced and studied in detail to manage with these problems. Now we briefly expose the main formal concepts which describe non-ideal situations, i.e. Probability, Statistics and Fuzzy Logic. Probability has recent origins with respect to other branches of mathematics which have deep roots in the past, like geometry or algebra.We may say all this started with Antoine Gombaud, Chevalier de Méré (1607–1684), who asked Blaise Pascal (1623–1662) about gambling with dice. The correspondence between Pierre de Fermat and Blaise Pascal, which began in 1654, initially on these questions, led to the introduction of basic concepts, i.e. probability and expectation. Only in 1657, Christian Huygens in "De Ratiociniis in ludo aleae" proposed a first systematic study of the new branch of mathematics. However, the need of an axiomatic construction of the theory of probability arose to analyze more general and complex situations than gambling. A strong formalization was supplied by the monograph "Foundations of the theory of probability" (1933) by Andrey Nikolaevich Kolmogorov.Statistics represent the most popular application of probability theory, providing research tools in several areas, including physical and natural sciences, technology, psychology, economics and medicine. Statistics are the bridge that connects experimental data to the mathematical theory behind itself.Fuzzy logic, sometime confused with probability, wants to express and formalize all the sentences which are not true or false at all; the philosophical idea is that "everything is a matter of degree" (Zadeh). La logica della probabilità: un viaggio attraverso l’incertezzaNella vita reale ci si trova di fronte a molte situazioni caratterizzate da incertezza, imprecisione, vaghezza. Sono state introdotte diverse modellizzazioni per il trattamento di tali concetti e problemi. Ci proponiamo di esporre sinteticamente alcuni lineamenti fondamentali di Probabilità, Statistica e Fuzzy Logic.La probabilità ha origini recenti rispetto alle altre branche della matematica che hanno profonde radici nel passato, come la geometria o l’algebra.Possiamo dire che un passaggio iniziale importante si è avuto con Antoine Gombaud, Chevalier de Méré (1607-1684), che pose a Blaise Pascal (1623-1662) una questione riguardante il gioco dei dadi. La corrispondenza tra Pierre de Fermat e Blaise Pascal, che ha avuto inizio nel 1654, su questioni simili, ha portato all'introduzione di concetti di base, come probabilità e aspettativa. Successivamente Christian Huygens, in "De ludo Ratiociniis in aleae", ha proposto un primo studio sistematico della nuova branca della matematica. Tuttavia, la necessità di una costruzione assiomatica della teoria della probabilità sorse per l’esigenza di analizzare situazioni più generali e complesse rispetto al gioco d'azzardo. Una forte formalizzazione è stata fornita dalla monografia "Fondamenti della teoria della probabilità" (1933) di Andrey Nikolaevich Kolmogorov.La statistica rappresenta l'applicazione più popolare della teoria della probabilità, fornendo strumenti di ricerca in diversi settori, tra cui le scienze fisiche e naturali, la tecnologia, la psicologia, l'economia e la medicina. In un certo senso essa rappresenta il ponte che collega i dati sperimentali con la teoria matematica.La Logica Fuzzy, da non confondere con la probabilità, si occupa del trattamento formale delle proposizioni di cui non si può affermare senza ambiguità che siano vere o false; l'idea filosofica è che "tutto è una questione di gradualità" (Zadeh).Parole Chiave: Incertezza, Probabilità, Statistica, Fuzz

Occurrence of a case of influenza A(H1N1)pdm09 and B co-infection during the epidemic season 2012–2013

We report the detection of one case of co-infection with influenza A(H1N1)pdm09 and B, occurred during the 2012–2013 influenza season in Sicily. The dual infection was identified in a 18-year-old boy, who was not covered by specific vaccination and who had no other pre-existing risk factors. He presented classical symptoms of influenza-like illness developing no respiratory complications. A(H1N1)pdm09 viral concen- tration was initially about 10-fold higher than B virus, whereas its clearance was more rapidly achieved than in the case of B virus infection. Although influenza co-infection appears to be a rare event, a contin- ued influenza surveillance activity is recommended, in order to evaluate diversity and evolution, but also to support public health prevention measures

VtoV: a perceptual cue for rhythm identification

Current metrics for the quantification of speech rhythm take into account parameters not easily detectable by listeners. To overcome this limit, in this study we propose a new model based on a parameter that account for listeners' ability to discriminate between different rhythmic patterns. Starting from the results of a spectro-acoustic analysis conducted on singing, we found that Perceptual Centres align close to Vowel Onset Points (VOP). To test the perceptual relevance of interval between two consecutive VOPs, that we call VtoV intervals, we analyzed a multilingual corpus of TV news, advertisings and recited speech. The signal was segmented into vocalic/consonantal portions and into VtoV intervals. The standard deviation of all parameters was calculated. The results of the analysis show that VtoV is a crucial parameter both to classify languages on a rhythmic basis and to account for intra-linguistic speech style variations

Trimetazidine improves left ventricular function in diabetic patients with coronary artery disease: a double-blind placebo-controlled study

BACKGROUND: Patients with diabetic cardiomyopathy have an impaired myocardial glucose handling and distal distribution of coronary atherosclerosis. Trimetazidine, an anti-ischemic metabolic agent, improves myocardial glucose utilization though inhibition of fatty acid oxidation. Aim of the present study was to evaluate whether the metabolic effect of trimetazidine on left ventricular function in patients with diabetic cardiomyopathy. METHODS: 32 patients (24 males and 8 females, mean (SE) age = 67 ± 6 years) with type 2 diabetes and ischemic cardiomyopathy were randomized to receive either trimetazidine (20 mg, t.d.s.) or placebo (t.d.s.) for six months in a randomized parallel study. Patients performed an echocardiogram at baseline and after 6 months. RESULTS: Demographic data were comparable between the two groups. After six month baseline left ventricular end-diastolic diameters increased from 62.4 ± 1.7 to 63 ± 2.1 mm in the placebo group, while decreased from 63.2 ± 2.1 to 58 ± 1.6 mm (p < 0.01 compared to baseline) in the trimetazidine group. Compared to baseline, left ventricular ejection fraction increased by 5.4 ± 0.5% (p < 0.05) in the trimetazidine group while remained unchanged in the placebo group -2.4 ± 1.1% (NS), p < 0.01 between groups. A significant improvement in wall motion score index and in the E/A wave ratio was detected in patients treated with trimetazidine, but not in those receiving placebo. CONCLUSION: in diabetic patients with ischemic heart disease trimetazidine added to standard medical therapy has beneficial effect on left ventricular volumes and on left ventricular ejection fraction compared to placebo. This effect may be related to the effect of trimetazidine upon cardiac glucose utilization

Imitation/self-imitation in computer-assisted prosody training for Chinese learners of L2 Italian.

Recent studies on L2 acquisition, speech synthesis and automatic identification of foreign accents argue for a major role of prosody in the perception of non-native speech. Research on the relationship between pronunciation improvement and student/teachers’ voice similarities has also shown that the better the match between the learners' and native speakers' voices in terms of f0 and articulation rate, the more positive the impact on pronunciation training. This study investigates the effects of imitation and self-imitation on the acquisition of L2 suprasegmental patterns. Degree of foreign accent, improvements in intelligibility, and effectiveness of communication were measured to determine the success of each technique. For this purpose, a prosodic transplantation technique and a computer-assisted learning methodology were used. Recent studies on L2 acquisition, speech synthesis and automatic identification of foreign accents argue for a major role of prosody in the perception of non-native speech. Research on the relationship between pronunciation improvement and student/teachers’ voice similarities has also shown that the better the match between the learners' and native speakers' voices in terms of f0 and articulation rate, the more positive the impact on pronunciation training. This study investigates the effects of imitation and self-imitation on the acquisition of L2 suprasegmental patterns. Degree of foreign accent, improvements in intelligibility, and effectiveness of communication were measured to determine the success of each technique. For this purpose, a prosodic transplantation technique and a computer-assisted learning methodology were used