1,720,978 research outputs found
The Hedonic Experience Associated with a Gentle Touch Is Preserved in Women with Fibromyalgia
Full text linkBackground/Objectives: Although manual therapies can be used for pain alleviation in fibromyalgia, there is no clear evidence about the processing of gentle, affective touch in this clinical condition. In fact, persistent painful sensations and psychological factors may impact the hedonic experience of touch. Methods: This observational cross-sectional study compared the subjective experience of affective touch between 14 women with fibromyalgia (age range: 35–70; range of years of education: 5–13) and 14 pain-free women (age range: 18–30; range of years of education: 13–19). The participants rated the pleasantness of slow and fast touches delivered by a brush, the experimenter’s hand, and a plastic stick. Tactile stimuli were either imagined or real to disentangle the contribution of top-down and bottom-up sensory components. Additionally, a self-report questionnaire explored the lifetime experiences of affective touch. Results: Akin to healthy counterparts, individuals with fibromyalgia rated slow touches delivered by the experimenter’s hand or a brush as more pleasant than fast touches, regardless of whether they were imagined or real. However, the intensity of pain affects only the imagined pleasantness in our participants with fibromyalgia. Furthermore, despite the fibromyalgia patients reporting fewer experiences of affective touch in childhood and adolescence, this evidence was not associated with the experimental outcomes. Conclusions: The hedonic experience of affective touch seems preserved in fibromyalgia despite poor intimate bodily contact in youth. We confirmed that bottom-up and top-down factors contribute to the affective touch perception in fibromyalgia: bodily pain may impact even more the expected pleasure than the actual experience. Future investigations may introduce neurophysiological measures of the implicit autonomic responses to affective touch in fibromyalgia. To conclude, although preliminary, our evidence may be in favor of manual therapies for pain relief in fibromyalgia
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
When fruits lose to animals: Disorganized search of semantic memory in Parkinson’s Disease.
No full textObjective: The semantic fluency task is widely used in both clinical and research settings to assess both the
integrity of the semantic store and the effectiveness of the search through it. Our aim was to investigate
whether nondemented Parkinson’s disease (PD) patients show an impairment in the strategic exploration of
the semantic store and whether the tested semantic category has an impact on multiple measures of
performance. Method: We compared 74 nondemented PD patients with 254 healthy subjects in a semantic
fluency test using relatively small (fruits) and large (animals) semantic categories. Number of words produced,
number of explored semantic subcategories, and degree of order in the produced sequences were computed
as dependent variables. Results: PD patients produced fewer words than healthy subjects did, regardless of the
category. Number of subcategories was also lower in PD patients than in healthy subjects, without a significant
difference between categories. Critically, PD patients’ sequences were less semantically organized than were
those of controls, but this effect appeared in only the smaller category (fruits), thus pointing to a lack of
strategy in exploring the semantic store. Conclusions: Our results show that the semantic fluency deficit in PD
patients has a strategic component, even though that may not be the only cause of the impaired performance.
Furthermore, our evidence suggests that the semantic category used in the test influences performance, hence
providing an explanation for the failure by previous studies, which often used large categories such as animals,
to detect strategy deficits in PD
When Fruits Lose to Animals: Disorganized Search of Semantic Memory in Parkinson's Disease
No full textObjective: The semantic fluency task is widely used in both clinical and research settings to assess both the integrity of the semantic store and the effectiveness of the search through it. Our aim was to investigate whether nondemented Parkinson's disease (PD) patients show an impairment in the strategic exploration of the semantic store and whether the tested semantic category has an impact on multiple measures of performance. Method: We compared 74 nondemented PD patients with 254 healthy subjects in a semantic fluency test using relatively small (fruits) and large (animals) semantic categories. Number of words produced, number of explored semantic subcategories, and degree of order in the produced sequences were computed as dependent variables. Results: PD patients produced fewer words than healthy subjects did, regardless of the category. Number of subcategories was also lower in PD patients than in healthy subjects, without a significant difference between categories. Critically, PD patients' sequences were less semantically organized than were those of controls, but this effect appeared in only the smaller category (fruits), thus pointing to a lack of strategy in exploring the semantic store. Conclusions: Our results show that the semantic fluency deficit in PD patients has a strategic component, even though that may not be the only cause of the impaired performance. Furthermore, our evidence suggests that the semantic category used in the test influences performance, hence providing an explanation for the failure by previous studies, which often used large categories such as animals, to detect strategy deficits in PD
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
Effetto della polarizzazione catodica sull’infragilimento da idrogeno di un acciaio inossidabile martensitico a elevata resistenza
No full textScopo di questa ricerca è studiare l’effetto del potenziale di polarizzazione catodica, considerando in via conservativa anche l’eventuale presenza di tensioni residue, sul comportamento di acciai a elevata resistenza meccanica nei confronti dell’infragilimento da idrogeno. Infatti è ben noto che tali materiali, specie in ambienti “sour” e in determinate condizioni di protezione catodica, possono essere suscettibili di infragilimento da idrogeno e il loro utilizzo, come riportato da varie normative internazionali (DNV, ISO), è consentito solo considerando anche un limite inferiore per il potenziale di polarizzazione.
Il materiale oggetto di questo lavoro, cioè l’acciaio inossidabile martensitico AISI 420 C, è suscettibile all’infragilimento da idrogeno. La sperimentazione è stata condotta mediante prove a deformazione costante, in soluzione acetica (pH 5,5 a temperatura ambiente) senza solfuri e a diversi potenziali di polarizzazione catodica. Il livello di sforzo nei provini è stato mantenuto in campo elastico, dal 20% al 100% del carico di snervamento, per 720 ore.
Per i provini preparati in accordo alla normativa sono state individuate soglie di potenziale e sforzo applicato per la prevenzione dell’infragilimento, che avviene per valori di sforzo superiori al 60% dello snervamento a potenziali di -0.9 V vs. Ag/AgCl. A potenziali più elevati come -0.60 e -0.70 V vs. Ag/AgCl lo sforzo di soglia aumenta fino al valore dello snervamento. In presenza di sforzi residui dovuti alla lavorazione meccanica lo sforzo di soglia applicato si riduce fino al 20% dello snervamento e il tempo a rottura è molto ridotto; anche una prepolarizzazione catodica peggiora il comportamento, anche se in misura meno severa. I risultati suggeriscono che la prevenzione dell’infragilimento da idrogeno può essere raggiunta mediante polarizzazione catodica, ma le soglie critiche devono essere stabilite in modo più conservativo di quelle previste dalle norme considerando che, nelle applicazioni reali, i difetti possono essere comunque presentiThe goal of this research is to study the effect of the cathodic polarization potential on hydrogen embrittlement behaviour of high strength steels, considering for a conservative approach also the presence of defects (residual stresses). In fact, it is well known that in sour environments and in specific cathodic protection conditions these materials, may suffer hydrogen embrittlement and their use, as reported in different international standards (DNV, ISO) is allowed only considering a minimum threshold for the cathodic potential.
The studied material is a martensitic stainless steel type AISI 420 (quenched and tempered), is susceptible to hydrogen embrittlement. Constant deformation tests (three point bending) have been carried out on Bent-Beam specimens cathodically polarised in acetic solution, pH 5.5 at room temperature, without H2S. The stress level has been imposed in the elastic range, from 20% to 100% of the yield strength.
In absence of residual stresses, for specimens prepared according to standard, threshold for the potential and stress level have been identified: hydrogen embrittlement occurs for stress equal to or higher than 60% of the material yield strength at potential of -0.90 V vs. Ag/AgCl. At nobler potentials as -0.60 and -0.70 V vs. Ag/AgCl the critical stress threshold is increased to the value of the yield strength. The presence of defects, as residual stresses, worsens significantly the behavior: critical stress threshold is lowered to 20% of the yield strength and time to failure is reduced; also a cathodic prepolarisation worsen the behavior, but the effect is less severe. The results suggest that prevention of hydrogen embrittlement can be achieved by
means of cathodic protection, but the critical thresholds should be evaluated in more conservative way assuming that, in field applications, defects are probably present in the material
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
- …
