168 research outputs found
La messa in sicurezza dell'area industriale di Priolo-Augusta rispetto ai rischi da terremoto e maremoto
I recenti forti terremoti che hanno interessato zone particolarmente industrializzate in
Turchia ed in India (terremoto del 17.8.1999, Kocaeli, Turchia, Mw = 7.4; e terremoto
di Guyarat, India, del 26.01.2001, Mw =7.7) hanno messo in evidenza che al
danno prodotto dal terremoto si pu\uf2 aggiungere quello dovuto alle conseguenze di
incidenti e/o rotture negli impianti, cosiddetti, \u201ca rischio di incidente rilevante\u201d. Il rischio
totale nell\u2019area pu\uf2 quindi assumere valori estremamente elevati in termini economici,
ambientali, e talvolta con perdita di vite umane. Ad esempio, nel caso del terremoto turco,
il danneggiamento della raffineria Tupras di IZMIT ha provocato l\u2019incendio della stessa
e la fuoriuscita di una quantit\ue0 rilevante di olio (Foto 1). Sulla base di quanto sopra e di quanto conosciuto, il presente studio si propone come
elemento di base per l\u2019impostazione di interventi strutturali sugli impianti e sul territorio
con l\u2019obiettivo di mettere il tutto in condizioni di sicurezza a fronte del terremoto
(ed eventuale maremoto associato) atteso nell\u2019area.
A questo scopo \ue8 stata realizzata un\u2019analisi per mettere in evidenza l\u2019entit\ue0 e la frequenza
dei fenomeni naturali (terremoti e maremoti) che possono determinare significativi
impatti sia sull\u2019ambiente fisico che su quello antropizzato (infrastrutture) nell\u2019area
di Priolo-Augusta. Il progetto ha avuto come obiettivo iniziale la valutazione dei carichi
dovuti a fenomeni naturali che, trasformati in termini ingegneristici, devono essere utilizzati per la verifica della idoneit\ue0 progettuale degli impianti industriali presenti
nelle aree studiate. In particolare \ue8 stato valutato, dapprima, il terremoto di riferimento
per la progettazione, in termini di picco massimo di accelerazione e spettro di risposta
associato. In tale fase si \ue8 anche provveduto alla costruzione di scenari associati ad
un eventuale maremoto. I siti prescelti sono esposti ad un elevato rischio sismico la cui
definizione ha richiesto l\u2019adozione delle metodologie pi\uf9 avanzate disponibili. A tale
scopo sono stati applicati diversi approcci innovativi sia di tipo sismologico che ingegneristico
Hemodynamic and EEG Time-Courses During Unilateral Hand Movement in Patients with Cortical Myoclonus. An EEG-fMRI and EEG-TD-fNIRS Study.
Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TD-fNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated O(2)Hb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the alpha and beta bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TD-fNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in O(2)Hb and the decrease in BOLD. The post-movement beta rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG beta-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies
EEG-informed fMRI analysis during a hand grip task: estimating the relationship between EEG rhythms and the BOLD signal.
In the last decade, an increasing interest has arisen in investigating the relationship between the electrophysiological and hemodynamic measurements of brain activity, such as EEG and (BOLD) fMRI. In particular, changes in BOLD have been shown to be associated with changes in the spectral profile of neural activity, rather than with absolute power. Concurrently, recent findings showed that different EEG rhythms are independently related to changes in the BOLD signal: therefore, it would be also important to distinguish between the contributions of the different EEG rhythms to BOLD fluctuations when modeling the relationship between the two signals. Here we propose a method to perform EEG-informed fMRI analysis where the changes in the spectral profile are modeled, and, at the same time, the distinction between rhythms is preserved. We compared our model with two other frequency-dependent regressors modeling using simultaneous EEG-fMRI data from healthy subjects performing a motor task. Our results showed that the proposed method better captures the correlations between BOLD signal and EEG rhythms modulations, identifying task-related, well localized activated volumes. Furthermore, we showed that including among the regressors also EEG rhythms not primarily involved in the task enhances the performance of the analysis, even when only correlations with BOLD signal and specific EEG rhythms are explore
Specific Activation of Estrogen Receptor Alpha and Beta Enhances Male Sexual Behavior and Neuroplasticity in Male Japanese Quail
Two subtypes of estrogen receptors (ER), ERα and ERβ, have been identified in humans and numerous vertebrates, including the Japanese quail. We investigated in this species the specific role(s) of each receptor in the activation of male sexual behavior and the underlying estrogen-dependent neural plasticity. Castrated male Japanese quail received empty (CX) or testosterone-filled (T) implants or were daily injected with the ER general agonist diethylstilbestrol (DES), the ERα-specific agonist PPT, the ERβ-specific agonist DPN or the vehicle, propylene glycol. Three days after receiving the first treatment, subjects were alternatively tested for appetitive (rhythmic cloacal sphincter movements, RCSM) and consummatory aspects (copulatory behavior) of male sexual behavior. 24 hours after the last behavioral testing, brains were collected and analyzed for aromatase expression and vasotocinergic innervation in the medial preoptic nucleus. The expression of RCSM was activated by T and to a lesser extent by DES and PPT but not by the ERβagonist DPN. In parallel, T fully restored the complete sequence of copulation, DES was partially active and the specific activation of ERα or ERβ only resulted in a very low frequency of mount attempts in few subjects. T increased the volume of the medial preoptic nucleus as measured by the dense cluster of aromatase-immunoreactive cells and the density of the vasotocinergic innervation within this nucleus. DES had only a weak action on vasotocinergic fibers and the two specific ER agonists did not affect these neural responses. Simultaneous activation of both receptors or treatments with higher doses may be required to fully activate sexual behavior and the associated neurochemical events
Arterially Perfused Neurosphere-Derived Cells Distribute Outside the Ischemic Core in a Model of Transient Focal Ischemia and Reperfusion In Vitro
BACKGROUND: Treatment with neural stem cells represents a potential strategy to improve functional recovery of post-ischemic cerebral injury. The potential benefit of such treatment in acute phases of human ischemic stroke depends on the therapeutic viability of a systemic vascular delivery route. In spite of the large number of reports on the beneficial effects of intracerebral stem cells injection in experimental stroke, very few studies demonstrated the effectiveness of the systemic intravenous delivery approach. METODOLOGY/PRINCIPAL FINDINGS: We utilized a novel in vitro model of transient focal ischemia to analyze the brain distribution of neurosphere-derived cells (NCs) in the early 3 hours that follow transient occlusion of the medial cerebral artery (MCA). NCs obtained from newborn C57/BL6 mice are immature cells with self-renewal properties that could differentiate into neurons, astrocytes and oligodendrocytes. MCA occlusion for 30 minutes in the in vitro isolated guinea pig brain preparation was followed by arterial perfusion with 1x10(6) NCs charged with a green fluorescent dye, either immediately or 60 minutes after reperfusion onset. Changes in extracellular pH and K(+) concentration during and after MCAO were measured through ion-sensitive electrodes. CONCLUSION/SIGNIFICANCE: It is demonstrated that NCs injected through the vascular system do not accumulate in the ischemic core and preferentially distribute in non-ischemic areas, identified by combined electrophysiological and morphological techniques. Direct measurements of extracellular brain ions during and after MCA occlusion suggest that anoxia-induced tissue changes, such as extracellular acidosis, may prevent NCs from entering the ischemic area in our in vitro model of transitory focal ischemia and reperfusion suggesting a role played by the surrounding microenviroment in driving NCs outside the ischemic core. These findings strongly suggest that the potential beneficial effect of NCs in experimental focal brain ischemia is not strictly dependent on their homing into the ischemic region, but rather through a bystander mechanism possibly mediated by the release of neuroprotective factors in the peri-infarct region
Parma consensus statement on metabolic disruptors
A multidisciplinary group of experts gathered in Parma Italy for a workshop hosted by the University of Parma, May 16–18, 2014 to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders. The objectives of the workshop were to: 1. Review findings related to the role of environmental chemicals, referred to as “metabolic disruptors”, in obesity and metabolic syndrome with special attention to recent discoveries from animal model and epidemiology studies; 2. Identify conclusions that could be drawn with confidence from existing animal and human data; 3. Develop predictions based on current data; and 4. Identify critical knowledge gaps and areas of uncertainty. The consensus statements
are intended to aid in expanding understanding of the role of metabolic disruptors in the obesity and metabolic disease epidemics, to move the field forward by assessing the current state of the science and to identify research needs on the role of environmental chemical exposures in these diseases. We propose broadening the definition of obesogens to that of metabolic disruptors, to encompass chemicals that play a role in altered susceptibility to obesity, diabetes and related metabolic disorders including metabolic syndrome
Activational effects of estradiol and dihydrotestosterone on social recognition and the arginine-vasopressin immunoreactive system in male mice lacking a functional aromatase gene.
In rodents, parts of the arginine-vasopressin (AVP) neuronal system are sexually dimorphic with males having more AVP-immunoreactive cells/fibers than females. This neuropeptide neuronal system is highly sensitive to steroids and has been proposed to play an important role in the processing of olfactory cues critical to the establishment of a social memory. We demonstrate here that gonadally intact male aromatase knockout (ArKO) mice, which cannot aromatize androgens into estrogens due to a targeted mutation in the aromatase gene, showed severe deficits in social recognition as well as a reduced AVP-immunoreactivity in several brain regions. To determine whether this reduction is due to a lack of organizational or activational effects of estrogens, we assessed social recognition abilities and AVP-immunoreactivity in male ArKO and wild-type (WT) mice when treated with estradiol benzoate (EB) in association with dihydrotestosterone propionate (DHTP) in adulthood. Adult treatment with EB and DHTP restored social recognition abilities in castrated ArKO males since they showed normal female-oriented ultrasonic vocalizations and were able to recognize an unfamiliar female using a habituation-dishabituation paradigm. Furthermore, adult treatment also restored AVP-immunoreactivity in the lateral septum of ArKO males to levels observed in intact WT males. These results suggest that social recognition in adulthood and stimulation of AVP expression in the adult mouse forebrain depend predominantly on the estrogenic metabolite of testosterone. Furthermore, our results are in line with the idea that the organization of the AVP system may depend on androgen or sex chromosomes rather than estrogens
Inglese con la LIM alla scuola primaria
In questo libro gli insegnanti troveranno le riflessioni di esperti di applicazioni delle nuove tecnologie nell\u2019ambito della didattica dell\u2019inglese come L2 e tre moduli didattici per la scuola primaria.
Il volume fa parte della collana \uabCLIM (Classe Interattiva Multimediale)\ubb, che mette a disposizione degli insegnanti della scuola primaria e della secondaria di primo grado gli studi e gli strumenti pi\uf9 aggiornati sulla didattica con la Lavagna Interattiva Multimediale (LIM) e, pi\uf9 in generale, con le nuove tecnologie.
L\u2019obiettivo \ue8 di far acquisire le competenze teoriche e pratiche per introdurre in aula i dispositivi didattici digitali \u2014 primo fra tutti la Lavagna Interattiva Multimediale \u2014 attraverso la presentazione di alcuni percorsi di insegnamento e delle modalit\ue0 corrette per allestire e gestire i materiali inclusi in ogni volume della serie (italiano, storia, scienze, ecc.)
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