1,721,208 research outputs found
Transcranial cerebellar direct current stimulation (tcDCS): motor control, cognition, learning and emotions
Full text linkThe neurological manifestations of cerebellar diseases range from motor to cognitive or behavioral abnormalities. Experimental data in healthy subjects extend the cerebellar role to learning, emotional and mood control. The need for a non-invasive tool to influence cerebellar function in normal and pathological conditions led researchers to develop transcranial cerebellar direct current stimulation (tcDCS). tcDCS, like tDCS, depends on the principle that weak direct currents delivered at around 2. mA for minutes over the cerebellum through surface electrodes induce prolonged changes in cerebellar function. tcDCS modulates several cerebellar skills in humans including motor control, learning and emotional processing. tcDCS also influences the cerebello-brain interactions induced by transcranial magnetic stimulation (TMS), walking adaptation, working memory and emotional recognition. Hence tcDCS is a simple physiological tool that can improve our physiological understanding of the human cerebellum, and should prove useful also in patients with cerebellar dysfunction or psychiatric disorders and those undergoing neurorehabilitation to enhance neuroplasticity
LA STIMOLAZIONE TRANSCRANICA A CORRENTI DIRETTE (TDCS) NEL TRATTAMENTO DELLA DEPRESSIONE: EFFETTI TERAPEUTICI E INTERAZIONE CON LA TERAPIA PSICOFARMACOLOGICA.
Full text linkINTRODUZIONE
La stimolazione transcranica con correnti dirette (transcranial Direct Current Stimulation, tDCS) è una metodica di stimolazione cerebrale non invasiva che consiste nell’applicazione sullo scalpo di corrente continua di bassa intensità non percepibile dal soggetto stimolato; la corrente è in grado di attraversare la teca cranica fino alla corteccia cerebrale. Negli ultimi anni tale metodica è stata utilizzata nello studio dei processi cognitivi, sia nei soggetti sani che nei pazienti affetti da disturbi neurologici e psichiatrici. Nessuno tra gli studi pubblicati ha sinora riportato gravi effetti collaterali o reazioni avverse. Nell’ambito specifico delle patologie psichiatriche la tDCS ha trovato già dagli anni ‘60 numerose applicazioni evidenziando effetti benefici. Tali risultati sono ulteriormente consolidati in recenti studi in cui la tDCS sembra svolgere un ruolo importante nella modulazione di quelle aree che nella depressione risultano essere ipoattive e iperattive ed esercitare così un effetto antidepressivo. Gli studi sulla depressione lieve e moderata hanno dimostrato che la tDCS ha un’efficacia terapeutica significativamente superiore al placebo e sovrapponibile a quella della Fluoxetina, ma con maggiore rapidità di azione e minori effetti collaterali rispetto a quest’ultima.
In questo studio abbiamo esaminato le interazioni tra la tDCS e la terapia farmacologica in 82 pazienti depressi (unipolari e bipolari) che erano refrattari ad almeno un trattamento farmacologico.
METODOLOGIA
Il campione è composto da 82 pazienti affetti da depressione maggiore grave e farmaco resistente. Tutti i soggetti sono stati sottoposti ad un trattamento con tDCS (Corteccia Prefrontale Dorsolaterale), somministrato due volte al giorno a distanza di 4h, per 5 giorni consecutivi (intensità di corrente: 2 mA per la durata di 20 minuti). Tutti i soggetti sono stati valutati in due tempi con la Beck depression Inventory (BDI), la Hamilton Depression Rating Scale: prima dell’inizio del trattamento (T0), alla fine dei 5 giorni di trattamento (T1).
RISULTATI
Dopo cinque giorni di trattamento la metodica ha prodotto un miglioramento significativo in entrambe le scale (BDI 29% ± 36%, p<0.01; HDRS 18% ± 9%, p<0.01),
I risultati hanno dimostrato che l’uso delle benzodiazepine è associato ad un aumento dei punteggi alla scala BDI (+5.8 punti) (p<0.01) mentre gli altri antidepressivi hanno un effetto contrario (p<0.01).
CONCLUSIONI
In conclusione, la tDCS può essere una strategia terapeutica complementare ed adiuvante nella malattia depressiva. L'uso di benzodiazepine ostacola l'efficacia tDCS mentre l'uso degli antidepressivi sembra avere un effetto migliorativo, pertanto, il trattamento farmacologico deve essere sempre considerato nell'interpretazione dei dati.Background: Transcranial direct current stimulation (tDCS) is a non-invasive,
neuromodulatory technique with an emerging role for treating major depression.
Objective: To investigate the interactions between tDCS and drug therapy in unipolar and bipolar depressed patients who were refractory for at least one pharmacological treatment.
Methods: This was a naturalistic study using data from 54 female and 28 male patients (mean age of 54 years) that consecutively visited our psychiatric unit. They received active tDCS (five consecutive days, 2mA, anodal stimulation over the left and cathodal over the right dorsolateral prefrontal cortex, twice a day, 20 minutes). The outcome variable (mood) was evaluated using the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HDRS). Predictor variables were age, gender, disorder and pharmacological treatment (seven dummy variables). We performed univariate and multivariate analyses as to identify predictors associated to the outcome.
Results: After 5 days of treatment BDI and HDRS scores decreased significantly (29% ± 36%, 18% ± 9%, respectively, p<0.01 for both). Benzodiazepine use was independently associated with a worse outcome in both univariate (β=4.92, p<0.01) and multivariate (β=5.8, p<0.01) analyses; whereas use of dual-reuptake inhibitors positively changed tDCS effects in the multivariate model (β=-4.7, p=0.02). A similar trend was observed for tricyclics (β=-4, p=0.06) but not for antipsychotics, non-benzodiazepine anticonvulsants and other drugs.
Conclusion: Anodal tDCS over the left DLPFC acutely improved depressive symptoms. Besides the inherent limitations of our naturalistic design, our results suggest that tDCS effects might vary according to prior pharmacological treatment, notably benzodiazepines and some antidepressant classes. This issue should be further explored in controlled studies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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