Abnormal reactivity of resting-state EEG alpha rhythms during eyes open in patients with Alzheimer's and Lewy body diseases

Previous studies suggest that resting-state electroencephalographic (rsEEG) rhythms recorded in old patients with dementia due to different neurodegenerative diseases have a significant heuristic and clinical potential in identifying peculiar abnormalities of the ascending activating systems and reciprocal thalamocortical circuits in which oscillatory (de)synchronizing signals dynamically underpin cortical arousal in the regulation of quiet vigilance. In the present PhD program, a new methodological approach based on rsEEG cortical source estimation and individually-based frequency bands was used to test the hypothesis of significant abnormalities in the neurophysiological oscillatory mechanisms underlying the regulation of the quiet vigilance during the transition from an eyes-closed to an eyes-open condition in patients with the most prevalent neurodegenerative dementing disorders such as Alzheimer’s disease and Lewy Body and Parkinson’s diseases and initial abnormalities in the prodromal stage of ADD, characterized by mild cognitive impairment. Three rsEEG studies were performed for that purpose. In the first study, we tested if the reactivity of posterior rsEEG alpha rhythms from the eye- closed to the eyes-open condition may differ in patients with dementia due to Lewy Bodies (DLB) and Alzheimer’s disease (ADD) as a functional probe of the dominant neural synchronization mechanisms regulating the vigilance in posterior visual systems. We used clinical, demographical, and rsEEG datasets in 28 healthy elderly (Healthy) seniors, 42 DLB, and 48 ADD participants. The eLORETA freeware estimated rsEEG cortical sources at individual delta, theta, and alpha frequencies. Results showed a substantial (> -10%) reduction in the posterior alpha activities during the eyes-open condition in 24 Healthy, 26 ADD, and 22 DLB subjects. There were lower reductions in the posterior alpha activities in the ADD and DLB groups than in the Healthy group. The reduction in the occipital region was lower in the DLB than in the ADD group. These results suggest that DLB patients may suffer a greater alteration in the neural synchronization mechanisms regulating vigilance in occipital cortical systems compared to ADD patients. In the second study, we hypothesized that the vigilance dysregulation seen in PDD patients might be reflected by altered reactivity of posterior rsEEG alpha rhythms during the vigilance transition from an eyes-closed to an eyes-open condition. We used clinical, demographical, and rsEEG datasets in 28 healthy elderly (Healthy), 73 PDD, and 35 ADD participants. We have applied the same methodology used for the first study. Results showed substantial (> -10%) reduction (reactivity) in the posterior alpha source activities from the eyes-closed to the eyes-open condition in 88% of the Healthy seniors, 57% of the ADD patients, and only 35% of the PDD patients. In these alpha-reactive participants, there was lower reactivity in the parietal alpha source activities in the PDD group than in the Healthy and the ADD groups. These results suggest that PDD is characterized by poor reactivity of mechanisms desynchronizing posterior rsEEG alpha rhythms in response to visual inputs. This finding could be an interesting biomarker of impaired vigilance regulation in quiet wakefulness in PDD patients. Indeed, such biomarkers may provide endpoints for pharmacological intervention and brain electromagnetic stimulations to improve the PDD patients’ general ability to regulate vigilance and primary visual consciousness in the activities of daily living. In the third study, we tested the exploratory hypothesis that rsEEG alpha rhythms may predict and be sensitive to mild cognitive impairment due to AD (ADMCI) progression at a 6-month follow- up (a relevant feature for intervention clinical trials). Clinical, neuroimaging, and rsEEG datasets in 52 ADMCI and 60 Healthy seniors were used. We applied the same methodology used for the first and the second studies. Results showed a substantial (> -10%) reduction in the posterior alpha source activities during the eyes-open condition in about 90% and 70% of the Healthy and ADMCI participants, respectively. In the younger ADMCI patients (mean age of 64.3±1.1) with “reactive” rsEEG alpha source activities, posterior alpha source activities during the eyes closed condition predicted the global cognitive status at the 6-month follow-up. In all ADMCI participants with “reactive” rsEEG alpha source activities, posterior alpha source activities during the eyes-closed condition reduced in magnitude at that follow-up. These effects could not be explained by neuroimaging and neuropsychological biomarkers of AD. These results suggest that in ADMCI patients, the true (“reactive”) posterior rsEEG alpha rhythms, when present, predict (in relation to younger age) and are quite sensitive to the effects of the disease progression on neurophysiological mechanisms underpinning vigilance regulation. The results of the three studies unveiled the significant extent to which the well-known impairments in the cholinergic and dopaminergic neuromodulatory ascending systems could affect the brain neurophysiological oscillatory mechanisms underpinning the reactivity of rsEEG alpha rhythms during eyes open and, then, the regulation of quiet vigilance in ADD, PDD, and DLB patients, thus enriching the neurophysiological model underlying their known difficulties to remain awake in quiet environmental conditions during daytime

Inclusions.

The paradigm based on the conceptual dichotomy between inclusion and exclusion – which has affected the modern era of political and legal thought – is definitely ineffective in portraying assets and institutions as well as political and social forms that currently frame the neoliberal governmentality

Population Change and International and Internal Migration in Italy, 2002-2017: Ravenstein Revisited

In 1885, Ravenstein formulated his "laws" of migration, based on the experience of the British Isles. In a further 1889 paper, he extended his analysis as a tour d’horizon of migration and population changes in other nations, including Italy. Even if social and economic processes including globalisation and rising mobility have changed the world since then, Ravenstein's "laws" remain a point of reference today. Harnessing theoretical and methodological advances made since the 19th century, this paper describes and seeks to explain the role of international and internal migration in regional population change in Italy from 2002-2017. This paper provides the first geographically detailed migration analysis for the country's 611 Local Labour Market Areas (LLMAs), using register-based migration and population data. Our contribution focuses on several of Ravenstein's "laws" relating to gender (differences between men and women), natives and non-natives (differences between the Italian and the foreign population), distance migrated from origin to destination, and the role of the economy in shaping push and pull factors of migration. The results show that international migration is more prominent among men than women. In the case of internal moves, the rates of migration among men and women are similar, and internal migration is more prominent among the foreign than the native Italian population. Overall, international migration gains contribute substantially more to population change than internal migration gains and losses do. In Italy, the effects of persistent economic imbalances and of distance on migration patterns are not in line with Ravenstein's hypotheses: not all areas with high unemployment show an effect of dispersion, nor does distance always act as a deterrent to migration. The geographically detailed analysis presented here illustrates the temporal and spatial coexistence of diverse international and internal migration processes depending on local characteristics, as well as the importance of the economic or administrative centres as the driving force behind national patterns. Our results show that, even 130 years after their formulation, Ravenstein’s migration "laws" (more accurately called "hypotheses" today) are still a valuable starting point in assessing and understanding migration processes and their role in regional population change

Separating polarized cosmological and galactic emissions for CMB B-mode polarization experiments

In this work we study the relevance of the component separation technique based on the Independent Component Analysis (ICA) and investigate its performance in the context of a limited sky coverage observation and from the viewpoint of our ability to differentiate between cosmological models with different primordial B-mode content. We focus on the low Galactic emission sky patch, corresponding to the target of several operating and planned CMB experiments and which, in many respects, adequately represents a typical "clean" high latitude sky. We consider two fiducial observations, one operating at low (40, 90 GHz) and one at high (150, 350 GHz) frequencies and thus dominated by the synchrotron and thermal dust emission, respectively. We use a parallel version of the FASTICA code to explore a substantial parameter space including Gaussian pixel noise level, observed sky area and the amplitude of the foreground emission and employ large Monte Carlo simulations to quantify errors and biases pertinent to the reconstruction for different choices of the parameter values. We identify a large subspace of the parameter space for which the quality of the CMB reconstruction is excellent. For both the cosmological models, with and without the primordial gravitational waves, we find that FASTICA performs extremely well even in the cases when the B mode CMB signal is up to a few times weaker than the foreground contamination and the noise amplitude is comparable with the total CMB polarized emission. In addition we discuss limiting cases of the noise and foreground amplitudes, for which the ICA approach fails.Comment: 19 pages, 12 figures, 5 tables, replaced to match published versio

Natural Magnetite Minerals Enhance 1,2-Dichloroethane Reductive Dechlorination

Contamination of soil and groundwater by chlorinated solvents is an environmental issue of primary concern. Recently, electrically conductive iron particles have been proposed as a novel approach to accelerate anaerobic bioremediation processes. In fact, it was demonstrated that conductive particles facilitate the exchange of electrons between microorganisms via Direct Interspecies Electron Transfer (DIET) processes, thus enhancing the pollutant-degrading potential of the microbial community. However, the use of natural minerals in this context has not been reported so far. In this study, we applied, for the first time, natural magnetite and hematite to accelerate the reductive dechlorination of 1,2-dichloroethane by an enrichment culture in lab-scale anaerobic microcosms. After four feeding cycles, low magnetite-amended microcosms (13 mg/L) yielded the highest rate of 1,2-DCA reductive dechlorination and reduced methanogenic activity. By contrast, hematite did not display any apparent stimulatory effect. Surprisingly, in the presence of higher amounts of iron oxides, a weaker effect was obtained, probably because iron(III) present in the minerals competed for the electrons necessary for reductive dechlorination. For all microcosms, the concentration of the toxic byproduct vinyl chloride was negligible throughout the whole study. The SEM/EDS analysis confirmed the close interaction between the conductive iron oxide particles and the dechlorinating bacteria. This work opens the possibility of using natural conductive minerals for bioremediation applications as well as shedding light on the previously unrecognized role of such minerals in contaminated ecosystemsThe authors would like to thank FCT (Portuguese Foundation for Science and Technology) for the financial support of Patrícia Leitão through the Ph.D. grant SFRH/BD/87312/2012info:eu-repo/semantics/publishedVersio

Poor reactivity of posterior electroencephalographic alpha rhythms during the eyes open condition in patients with dementia due to Parkinson's disease

Here, we hypothesized that the reactivity of posterior resting-state electroencephalographic (rsEEG) alpha rhythms during the transition from eyes-closed to -open condition might be lower in patients with Parkinson's disease dementia (PDD) than in patients with Alzheimer's disease dementia (ADD). A Eurasian database provided clinical-demographic-rsEEG datasets in 73 PDD patients, 35 ADD patients, and 25 matched cognitively unimpaired (Healthy) persons. The eLORETA freeware was used to estimate cortical rsEEG sources. Results showed substantial (greater than −10%) reduction (reactivity) in the posterior alpha source activities from the eyes-closed to the eyes-open condition in 88% of the Healthy seniors, 57% of the ADD patients, and only 35% of the PDD patients. In these alpha-reactive participants, there was lower reactivity in the parietal alpha source activities in the PDD group than in the healthy control seniors and the ADD patients. These results suggest that PDD patients show poor reactivity of mechanisms desynchronizing posterior rsEEG alpha rhythms in response to visual inputs. That neurophysiological biomarker may provide an endpoint for (non) pharmacological interventions for improving vigilance regulation in those patients.European Consortium of Dementia ; IRCCS San Raffaele Rome ; World Medical Association ; Ministero della Salute ; Sapienza Università di Rom

Enhancing the anaerobic biodegradation of petroleum hydrocarbons in soils with electrically conductive materials

: Anaerobic bioremediation is a relevant process in the management of sites contaminated by petroleum hydrocarbons. Recently, interspecies electron transfer processes mediated by conductive minerals or particles have been proposed as mechanisms through which microbial species within a community share reducing equivalents to drive the syntrophic degradation of organic substrates, including hydrocarbons. Here, a microcosm study was set up to investigate the effect of different electrically conductive materials (ECMs) in enhancing the anaerobic biodegradation of hydrocarbons in historically contaminated soil. The results of a comprehensive suite of chemical and microbiological analyses evidenced that supplementing the soil with (5% w/w) magnetite nanoparticles or biochar particles is an effective strategy to accelerate the removal of selected hydrocarbons. In particular, in microcosms supplemented with ECMs, the removal of total petroleum hydrocarbons was enhanced by up to 50% relative to unamended controls. However, chemical analyses suggested that only a partial bioconversion of contaminants occurred and that longer treatment times would have probably been required to drive the biodegradation process to completion. On the other hand, biomolecular analyses confirmed the presence of several microorganisms and functional genes likely involved in hydrocarbon degradation. Furthermore, the selective enrichment of known electroactive bacteria (i.e., Geobacter and Geothrix) in microcosms amended with ECMs, clearly pointed to a possible role of DIET (Diet Interspecies Electron Transfer) processes in the observed removal of contaminants