118,983 research outputs found
Alcune osservazioni attorno al crocifisso di Badia a Passignano
No full textElisabetta Fadda analizza il Crocifisso ligneo di Badia a Passignano (Tavarnelle in Val di Pesa, Firenze) e ne attribuisce l'esecuzione, assieme ad altre opere gemelle, alla bottega dei del Tasso
Scopolamine and MK801-induced working memory deficits in rats are not reversed by CBD-rich cannabis extracts
No full textSmoking marijuana causes working and short-term memory deficits, an effect that is mediated by cannabinoid receptor (CBI) activation in the brain. While this may be due to the main psychoactive constituent Delta(9)-tetrahydrocannabinol (Delta(9)-THC), plantextracts also contain other cannabinoid and terpenoid compounds with unknown properties. Towards this end, we have recently shown that high concentrations of plant extracts rich in cannabidiol (CBD) can reverse working memory deficits induced by Delta(9)-THC which is a remaining contaminant of this extract [Fadda P, Robinson L, Fratta W. Pertwee RG, Riedel G. Differential effects of THC- and CBD-rich cannabis-ex tracts on working memory in rats. Neuropahrmacology 2004:47:1170-9]. Since this effect was dose-dependent and indicative of memory enhancing qualities of the CBD-rich extract, this prompted a wider investigation into the effects of CBD on other forms of amnesia in order to determine the mechanism of action and to reveal its potency against anticholinergic and antiglutamatergic agents.
We employed a spatial delayed matching to position task in the open-field water maze. Both scopolamine (0.2 mg/kg i.p.) and dizocilpine (MK801: 0.1 mg/kg i.p.) impaired working memory at delays of 30 s and 4 h. Two doses of CBD-rich extracts (5 and 10 mg/kg), which did not affect working memory when given alone, were unable to reverse these deficits when co-administered with scopolamine or MK801.
These data suggest that reversal of working memory deficits by CBD-rich extracts are specific to the cannabinoid system and do not compensate for acutely induced cholinergic or glutamatergic receptor hypoactivity. (c) 2005 Elsevier B.V. All rights reserved
Chronic imipramine, L-sulpiride and mianserin decrease Corticotropin releasing Factor levels in the rat brain
No full textAmong clinically effective antidepressant drugs, the action mechanism of mianserin has recently been related to variations in corticotropin releasing factor (CRF) levels in the rat locus coeruleus. We describe a specific effect on CRF levels after chronic treatment with different antidepressants: mianserin (10 mg/kg), imipramine (20 mg/kg), both for 21 days, or L-sulpiride (1 mg/kg) for 15 days. While all antidepressants used greatly decreased CRF concentrations in the hypothalamus, only mianserin decreased CRF concentrations by 40% in extrahypothalamic sites. Acute treatments failed to modify CRF levels. Chronic treatment with mianserin did not affect CRF density either in the hypothalamus or the extrahypothalamic areas. This new finding may add another facet to the therapeutic action of certain antidepressants and in particular to the atypical profile of mianserin
The assessment of self and collective efficacy in volleyball
No full textSelf–efficacy is defined as belief in one’s capabilities to organize and execute the courses of actions required
to produce given attainments. Perceived Collective efficacy is defined as a group's shared belief in its conjoint
capabilities to organize and execute the courses of action required to produce given levels of attainments
(Bandura, 1997). To evaluate self and collective efficacy in Italian volleyball players at different competitive
levels we have constructed some non-hierarchical scales to assess specific aspects relevant for this sport, as
emotions regulation, approach to training, technical/tactical capabilities and communication. A preliminary
version was administrated to different samples using two_formats of rating scales: an 11-point and a 5-point
Likert scale. Statistical analysis led us to choose the 5-point scale format (Guicciardi, Fadda and Delitala, 2010)
and revealed a factorial structure composed of four dimensions. Based on the results of this study a new
version of the questionnaires was created and it was named VEBS (volleyball efficacy beliefs scales).Efficacy
scales were administered to an élite sample (n=133) along with other psychological tests (TEOSQ, GEQ, BIG
FIVE) to verify the structural validity. The scales showed adequate values of skewness and kurtosis and values
of Cronbach‘s alpha ranging from .69 to .95. Good fit indices emerged in CFA for self-efficacy (÷2=74.4, df=59,
CFI=.97, TLI=.97, RMSEA=.05) confirming the four factors model. In conclusion, the structural validity of
efficacy scales (of VEBS) has been confirmed, as well as their relationships with the task-orientation, cohesion
and some personality traits (energy and openness)
Sleep deprivation in the rat: An animal model of mania
No full textThe model of sleep deprivation in rats by the platform method has been extensively studied in our laboratory as a possible animal model of mania. At the end of the period of sleep deprivation, the rat does not fall asleep as soon as it is returned to its home cage, but shows a period of wakefulness of about 30 min, during which the animal presents a cohort of symptoms that appear to mimic those present in idiopathic mania. In particular, during this period the animal displays insomnia, a high degree of hyperactivity, irritability, aggressiveness, hypersexuality and stereotypy. Haloperidol (0.2 mg/kg) was effective in reducing latency to sleep, while L-sulpiride was much weaker (< 50 mg/kg). The dopamine D-1 receptor antagonist SCH 23390 exhibited an extremely high potency and efficacy in reducing sleep latency, a significant effect being observed with 3 mu g/kg. The administration of the specific D-1 receptor agonist SKF 38393 markedly prolonged the period of insomnia with the correlated behavioral syndrome. When lithium was added to the diet and consumed during the sleep deprivation period in adequate amounts to produce serum lithium levels of 0.7-1.0 mEq/l, sleep latency and locomotor activity were significantly reduced. The administration of naloxone (1-10 mg/kg) reduced the latency to sleep in a dose-related manner. By contrast, morphine (1 and 5 mg/kg, i.p.), beta-endorphin and [D-Ala(2),D-Leu(5)]enkephalin (i.c.v., 2 and 1 mu g, respectively) markedly prolonged the insomnia. The model not only represents a confirmation in the rat that sleep loss often precedes and may trigger a manic episode in man, but suggests that an opioid-dopamine interaction may play a pathogenetic role in mania
L. J. Prieto, ou de la solitude du penseur
No full textThe relation of L. J. Prieto (1926-1996) to the Saussurean legacy and the structuralist network particular enough that the word “ school” cannot be used to describe it. Prieto’s research was solely guided by constantly straining towards consistency, ignoring mainstream ideas. Notwithstanding, it is possible to sketch the network connecting Prieto to other giants of structuralist semiolinguistic thought, and to draw strong analogies between his theories and other, non-structural, forms of semiotics and philosophy of language (mainly pragmatism and analytical philosophy). The final – and less known – result of Prieto’s studies is cto be found in the volumes of Saggi di semiotica, revealing a comprehensive anthroposemiotic vision, dealing in a genuinely Saussurean fashion with problems often ignored by the mainstream structuralist tradition (e. g. a theory of institutions, which could play a role in the current debate in social ontology).L. J. Prieto (1926-1996) avait un rapport caractéristique avec l’héritage saussurien et structuraliste, qui n’était pas conditionné par une adhésion personnelle à une école (pas même par l’amitié avec A. Martinet) – mais seulement par son effort constant de cohérence, indépendamment de toute exigence de confrontation aux autres. Il est néanmoins possible de découvrir des analogies entre les théories priétiennes et d’autres formes, non structuralistes, de sémiotique et de philosophie du langage (principalement le pragmatisme et la philosophie analytique). La pensée de Prieto, arrivée à maturité et telle qu’elle apparaît dans les Saggi di Semiotica, témoigne de cette élaboration personnelle, à la fois pour sa vision anthropo-sémiotique globale et pour la façon dont ce penseur réexamine, dans un cadre saussurien, certains problèmes qui ont été souvent ignorés par la tradition structuraliste (par exemple, la théorie des institutions – ce qui semble être utile par rapport au débat actuel sur l’ontologie sociale).Fadda Emanuele. L. J. Prieto, ou de la solitude du penseur. In: Histoire Épistémologie Langage, tome 37, fascicule 2, 2015. "Faire école" en linguistique au XXe siècle : l'école de Genève. pp. 93-111
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