Mutations in the SPAST gene causing hereditary spastic paraplegia arerelated to global topological alterations in brain functional networks

Aim: Our aim was to describe the rearrangements of the brain activity related to genetic mutations in the SPAST gene. Methods: Ten SPG4 patients and ten controls underwent a 5 min resting state magnetoencephalography recording and neurological examination. A beamformer algorithm reconstructed the activity of 90 brain areas. The phase lag index was used to estimate synchrony between brain areas. The minimum spanning tree was used to estimate topological metrics such as the leaf fraction (a measure of network integration) and the degree divergence (a measure of the resilience of the network against pathological events). The betweenness centrality (a measure to estimate the centrality of the brain areas) was used to estimate the centrality of each brain area. Results: Our results showed topological rearrangements in the beta band. Specifically, the degree divergence was lower in patients as compared to controls and this parameter related to clinical disability. No differences appeared in leaf fraction nor in betweenness centrality. Conclusion: Mutations in the SPAST gene are related to a reorganization of the brain topology

Probing background ionization: Positive streamers with varying pulse repetition rate and with a radioactive admixture

Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive Krypton 85. We find that the general morphology of a positive streamer discharge in high purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding Krypton 85, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.Comment: 30 pages, 13 figure

Supplements consumption, health oriented behaviour and beyond

The dietary supplements use is constantly growing as proof that people pay always more attention to their diet and their physical status. Italy recorded the highest growth in the European market within 2008 and 2012. The reasons and the factors behind the consumption of dietary supplements are complex, combining social, psychological, knowledge and economic factors. In order to provide consumers’ profiles and to estimate the following relationship between them and the socio-demo, lifestyle, health-related behaviour, a survey study was conducted on a sample of 400 Italian consumers. The main results highlight the presence of four different profiles, distinguished mainly by different lifestyle, health needs and self-perceived health status. Through a logit regression it was also estimated the probability to consume the different categories of supplements for each profile. In this way, this study could provide useful hints to implement public health guidelines and to avoid a no-proper use of supplements

Dem reconstruction of coastal geomorphology from dinsar

The paper is focused on Digital Elevation Model (DEM) reconstruction from differential interferometry synthetic aperture radar (DInSAR). In doing so, conventional DInSAR procedures are implemented to three repeat passes of RADARSAT-1 SAR fine mode data (F1). Further, the multichannel MAP height estimator is implemented with phase unwrapping technique. Consequently, the multichannel MAP height estimator is used to eliminate the phase decorrelation impact from the interferograms. The study shows the performance of DInSAR method using the multichannel MAP height estimator is better than DInSAR technique which is validated by a lower range of error (0.01±0.11 m) with 90% confidence intervals. In conclusion, integration of the multichannel MAP height estimator with phase unwrapping produce accurate 3-D coastal geomorphology reconstruction

Valorization of second cheese whey through cultivation of extremophile microalga Galdieria sulphuraria

Second cheese whey (SCW) or “scotta” in Italian, is a side-stream from the manufacturing of “Ricotta” cheese, obtained after thermal coagulation of whey proteins residue in the cheese whey. Galdieria sulphuraria is a thermophilic red algae well known for its metabolic capabilities to grow on wastewater and other saline effluents. In this work, the valorisation of SCW as nutrient source for the growth of G. sulphuraria has been investigated using different concentrations of SCW. The biochemical and fatty acids composition of the biomass obtained has been evaluated too. Small differences have been observed in terms of biomass obtained after 12 days of cultivation between the SCW media and the relative control with the same amount of reducing sugars. The fatty acids composition of G. sulphuraria grown in SCW showed a higher content of polyunsaturated fatty acids compared to the control. The biomass productivity using SCW media has also been optimized through response surface methodologies with supplementation of nitrogen source obtaining a biomass dry weight higher than 10 g L−1

Flexible brain dynamics underpins complex behaviours as observed in Parkinson’s disease

Rapid reconfigurations of brain activity support efficient neuronal communication and flexible behaviour. Suboptimal brain dynamics is associated to impaired adaptability, possibly leading to functional deficiencies. We hypothesize that impaired flexibility in brain activity can lead to motor and cognitive symptoms of Parkinson’s disease (PD). To test this hypothesis, we studied the ‘functional repertoire’—the number of distinct configurations of neural activity—using source-reconstructed magnetoencephalography in PD patients and controls. We found stereotyped brain dynamics and reduced flexibility in PD. The intensity of this reduction was proportional to symptoms severity, which can be explained by beta-band hyper-synchronization. Moreover, the basal ganglia were prominently involved in the abnormal patterns of brain activity. Our findings support the hypotheses that: symptoms in PD relate to impaired brain flexibility, this impairment preferentially involves the basal ganglia, and beta-band hypersynchronization is associated with reduced brain flexibility. These findings highlight the importance of extensive functional repertoires for correct behaviour

Brain connectivity study by multichannel system based on superconducting quantum magnetic sensors

In the present paper, we will report results about experimental study of brain functional connectivity performed by using a multichannel magnetoencephalographic system based on superconducting quantum interference devices. Such quantum devices exhibit magnetic field sensitivity high enough as to measure the extremely weak magnetic signals generated by the electrical neuronal activity. This powerful tool allows to study the temporal relation of spatially neurophysiological events, i.e. the functional connectivity, which recently captured attention in the field of brain function exploration. The paper reports system and sensors performance as well as data acquisition system and a detailed pipeline data analysis will be described. Brain connectivity measurements relative to parents of children with autism spectrum disorder will be shown, highlighting the preliminary results in topological metrics for different sub-items of autism-spectrum quotient test

Neuronal Avalanches to Study the Coordination of Large-Scale Brain Activity: Application to Rett Syndrome

Many complex systems, such as the brain, display large-scale coordinated interactions that create ordered patterns. Classically, such patterns have been studied using the framework of criticality, i.e., at a transition point between two qualitatively distinct patterns. This kind of system is generally characterized by a scale-invariant organization, in space and time, optimally described by a power-law distribution whose slope is quantified by an exponent α. The dynamics of these systems is characterized by alternating periods of activations, called avalanches, with quiescent periods. To maximize its efficiency, the system must find a trade-off between its stability and ease of propagation of activation, which is achieved by a branching process. It is quantified by a branching parameter σ defined as the average ratio between the number of activations in consecutive time bins. The brain is itself a complex system and its activity can be described as a series of neuronal avalanches. It is known that critical aspects of brain dynamics are modeled with a branching parameter σ =, and the neuronal avalanches distribution fits well with a power law distribution exponent α = -3/2. The aim of our work was to study a self-organized criticality system in which there was a change in neuronal circuits due to genetic causes. To this end, we have compared the characteristics of neuronal avalanches in a group of 10 patients affected by Rett syndrome, during an open-eye resting-state condition estimated using magnetoencephalography, with respect to 10 healthy subjects. The analysis was performed both in broadband and in the five canonical frequency bands. We found, for both groups, a branching parameter close to 1. In this critical condition, Rett patients show a lower distribution parameter α in the delta and broadband. These results suggest that the large-scale coordination of activity occurs to a lesser extent in RTT patients

Acute alcoholic hepatitis, end stage alcoholic liver disease and liver transplantation: An Italian position statement.

lcoholic liver disease encompasses a broad spectrum of diseases ranging from steatosis steatohepatitis, fibrosis, and cirrhosis to hepatocellular carcinoma. Forty-four per cent of all deaths from cirrhosis are attributed to alcohol. Alcoholic liver disease is the second most common diagnosis among patients undergoing liver transplantation (LT). The vast majority of transplant programmes (85%) require 6 mo of abstinence prior to transplantation; commonly referred to as the "6-mo rule". Both in the case of progressive end-stage liver disease (ESLD) and in the case of severe acute alcoholic hepatitis (AAH), not responding to medical therapy, there is a lack of evidence to support a 6-mo sobriety period. It is necessary to identify other risk factors that could be associated with the resumption of alcohol drinking. The "Group of Italian Regions" suggests that: in a case of ESLD with model for end-stage liver disease < 19 a 6-mo abstinence period is required; in a case of ESLD, a 3-mo sober period before LT may be more ideal than a 6-mo period, in selected patients; and in a case of severe AAH, not responding to medical therapies (up to 70% of patients die within 6 mo), LT is mandatory, even without achieving abstinence. The multidisciplinary transplant team must include an addiction specialist/hepato-alcohologist. Patients have to participate in self-help groups