117,537 research outputs found
The neural correlates of developmental dyslexia: a new meta-analysis of 48 neuroimaging studies
No full textOver the last two decades, developmental dyslexia has been the focus of much research using functional neuroimaging. A wide range of paradigms, tackling different neurocognitive domains, has been used to assess its neural correlates. The main trust of this work is that typical developmental dyslexics have dysfunction of the phonological and orthography to phonology conversion systems, normally housed in the left occipitotemporal cortex. It remains to be seen whether, besides this well replicated finding, there is a systematic co-occurrence of dysfunctional patterns of different functional systems perhaps converging on the same brain regions associated with the reading deficit. Such evidence would be relevant for theories of dyslexia like, for example, the magnocellular one. To address this problem, we performed a meta-analysis based on an optimized hierarchical clustering algorithm (Cattinelli et al., 2012) which automatically grouped 1982 activation peaks, extracted from 48 neuroimaging studies (fMRI and PET), into clusters in which the activation peaks had minimized spatial variance. The data was based on the literature published up to December 2011 including experiments on reading but also on phonological awareness, motor control, visual motion perception and so forth.
The clustering analysis identified 82 clusters. The functional role of the clusters was assessed on the basis of statistical criteria. In particular, the binomial test was used to identify which clusters showed a specific activation effect for dyslexics rather than for controls.
The left inferior parietal lobule, the left middle temporal gyrus, the left fusiform gyrus and the left cerebellum showed a specific association with the normal control groups, not being active in the dyslexics; on the other hand early subdivisions of visual cortices, bilaterally, the left insula and the right opercular portion of the inferior frontal gyrus showed a specific association with the dyslexic subjects.
A qualitative analysis of each cluster was also performed to evaluate the distribution of the activations peaks in relation to the experimental task (e.g. reading, phonological awareness, motor learning, visual motion discrimination, etc.).
We found that the aforementioned difference in left fusiform gyrus was selectively due to a lack of commitment to reading in adult dyslexics while the same region showed occasional activation for more basic visual tasks. On the other hand, the specific activation of early visual cortices in dyslexics was associated with a variety of visual tasks with reading tasks playing a major role.
We conclude that the available literature demonstrates a specific lack of activation of the left occipitotemporal cortex in dyslexics that is specific for reading and for visuo-phonological tasks. The larger early occipital activations in dyslexics may represent a compensatory effort for the visual analysis of printed words in the absence of a higher-level visual-word form neural expertise.
References
Cattinelli I., Borghese A.N., Gallucci M., Paulesu E. (In Press) Reading the reading brain: a new meta-analysis of functional imaging data of reading. J. Neurolinguistic
Il pacchetto sicurezza 2009. Commento al d.l 23 febbraio 2009 n.11 conv. in l. 23 aprile 2009 n. 38 e alla l. 15 luglio 2009 n. 94, a cura di Mazza-Viganò, Torino, 2009.
No full textPerquisizioni "sul posto"
No full textPer contrastare le nuove forme di ciminalità legate al terrorismo interno ed internazionale il Legislatore ha recentemente recuperato lo strumento della perquisizione "sul posto" (art. 18-bis l. 31 luglio 2005 n. 155) in passato ampiamente utilizzato in altri contesti. Il lavoro ne analizza struttura e funzioni soffermandosi criticamente, in una prospettiva costituzionalmente orientata, sulle numerose incognite legate all'impiego di tale strumento
The neural correlates of developmental dyslexia: a new meta-analysis of PET and fMRI activation studies
No full textINTRODUZIONE
Developmental dyslexia has been the focus of much functional anatomical research. The main trust of this work is that typical developmental dyslexics have a dysfunction of the phonological and orthography to phonology conversion systems, in which the left occipito-temporal cortex has a crucial role.
It remains to be seen whether there is a systematic co-occurrence of dysfunctional patterns of different functional systems perhaps converging on the same brain regions associated with the reading deficit. Such evidence would be relevant for theories like, for example, the magnocellular/attentional or the motor/cerebellar ones, which postulate a more basic and anatomically distributed disorder in dyslexia.
METODO
We addressed this issue with a meta-analysis of all the imaging literature published until September 2013 using a combination of hierarchical clustering and activation likelihood estimates.
RISULTATI
The clustering analysis on 2360 peaks identified 193 clusters, 92 of which proved significant for spatial extent. Following binomial tests on the clusters, we found a normal-control specific (i.e. reduced involvement in dyslexics) left hemispheric network involving the left inferior frontal, premotor, supramarginal cortices and the left infero-temporal and fusiform region: these were specific for reading and the visual-to-phonology processes. There was also a more dorsal left fronto-parietal network: these clusters included peaks from tasks involving phonological manipulation, but also motoric or visuo-spatial perception/attention. No cluster was identified in area V5 for no task. No significant effects were found for cerebellar clusters either.
CONCLUSIONI
We conclude that the available literature demonstrates a specific lack of activation of the left occipitotemporal cortex in dyslexics that is specific for reading and reading-like behaviours and for visuo-phonological tasks. Additional deficits may be associated with dorsal fronto-parietal deficits
Prenatal Nutrition Containing Bisphenol A Affects Placenta Glucose Transfer: Evidence in Rats and Human Trophoblast
No full textThis work aims to clarify the effect of dietary supplementation with Bisphenol A (BPA), a chemical widely present in beverage and food containers, on placental glucose transfer and pregnancy outcome. The study was performed on female Sprague Dawley rats fed with a diet containing BPA (2.5, 25 or 250 μg/Kg/day) for a period of a month (virgin state) plus 20 days during pregnancy. Western blot analysis and immunohistochemistry were performed in placental tissues for glucose type 1 transporter (GLUT1). Furthermore, human trophoblast, HTR8-SV/neo cells, were used to evaluate the effect of BPA on glucose transport and uptake. Studies in rats showed that food supplementation with BPA, produces a higher fetal weight (FW) to placenta weight (PW) ratio at the lowest BPA concentration. Such low concentrations also reduced maternal weight gain in late pregnancy and up-regulated placental expression of GLUT1. Treatment of HTR8-SV/neo with the non-toxic dose of 1 nM BPA confirmed up-regulation of GLUT1 expression and revealed higher activity of the transporter with an increase in glucose uptake and GLUT1 membrane translocation. Overall, these results indicate that prenatal exposure to BPA affects pregnancy and fetal growth producing changes in the placental nutrients-glucose transfer
Reading the dyslexic brain: Multiple dysfunctional routes revealed by a new meta-analysis of PET and fMRI activation studies
No full textDevelopmental dyslexia has been the focus of much functional anatomical research. The main trust of this work is that typical developmental dyslexics have a dysfunction of the phonological and orthography to phonology conversion systems, in which the left occipito-temporal cortex has a crucial role. It remains to be seen whether there is a systematic co-occurrence of dysfunctional patterns of different functional systems perhaps converging on the same brain regions associated with the reading deficit. Such evidence would be relevant for theories like, for example, the magnocellular/attentional or the motor/cerebellar ones, which postulate a more basic and anatomically distributed disorder in dyslexia. We addressed this issue with a meta-analysis of all the imaging literature published until September 2013 using a combination of hierarchical clustering and activation likelihood estimation methods. The clustering analysis on 2360 peaks identified 193 clusters, 92 of which proved spatially significant. Following binomial tests on the clusters, we found left hemispheric network specific for normal controls (i.e., of reduced involvement in dyslexics) including the left inferior frontal, premotor, supramarginal cortices and the left infero-temporal and fusiform regions: these were preferentially associated with reading and the visual-to-phonology processes. There was also a more dorsal left fronto-parietal network: these clusters included peaks from tasks involving phonological manipulation, but also motoric or visuo-spatial perception/attention. No cluster was identified in area V5 for no task, nor cerebellar clusters showed a reduced association with dyslexics. We conclude that the examined literature demonstrates a specific lack of activation of the left occipito-temporal cortex in dyslexia particularly for reading and reading-like behaviors and for visuo-phonological tasks. Additional deficits of motor and attentional systems relevant for reading may be associated with altered functionality of dorsal left fronto-parietal corte
Endocrine control of reptilian viviparity. Signal molecules in human and animal gestation.
No full textCapitolo
The role of educative thought in the life and work of Antonio Gramsci
No full textMany philosophers have propounded a vision of an improved society, what distinguishes Antonio Gramsci is his continuous effort to make it happen by understanding the process in order to put into practice. Gramsci's conviction about the importance of educative development came from both theory and experience. While there has been considerable examination of Gramsci's work in relation to the Prison Notebooks, this study will seek to address a lacuna in Gramsci scholarship. Using Gramsci's philological method, I analyse Gramsci's pre-prison activity; his pre-prison articles and letters, which, together with his letters from prison, formed part of his educative mission. This educative process was necessary, in order to construct a new party which would develop a collective will, collaboratively, with the masses.In this study therefore, I explore the contexts and formative experiences of the first part of his life together with the intellectual sources from which Gramsci developed his later theories, making central hitherto underemphasised connections between them which informed his writing and ideas. I intend to illustrate that Gramsci's underlying purpose in his writing, and political activity, was not only practical, on how to create a new socialist ruling class, but also educative in forming the mindset and values of his comrades. So that in addition to outlining his vision of a new order, he implicitly guided or explicitly explained the processes by which the necessary changes in social relations and moral climate could be made in order to achieve it. Each person had to engage with the values of the new order so that each could contribute to the construction of a new robust state. It was essential to build a hegemony at the most profound level, one which was dependent on collective understandings and a collective will
The lymphatic route. VII. Distribution of recombinant human interleukin-2 in rabbit plasma and lymph
No full textAdministration of IL-2 via the lymphatic route in laboratory animals. The study shows that lymphatic route could be a valid alternative to iv administratio
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