1,721,312 research outputs found
Adultos mayores sanos y deterioro cognitivo leve: funciones ejecutivas y reserva cognitiva
No full textEl deterioro cognitivo leve (MCI, por la sigla en inglés de mildcognitiveimpairment) es un trastorno heterogéneo caracterizado por un deterioro de las funciones cognitivas, variando su prevalencia entre un 3% a un 40%, diferencia que depende de la definición de MCI, de los test utilizados y de los baremos. Muchos estudios indican una alta probabilidad de conversión de un tipo de demencia, pero también la reversibilidad, lo que hace relevante un diagnóstico precoz y eficaz. La disfunción ejecutiva parece común en los pacientes con MCI y se relaciona con un pronóstico peor. Sin embargo, tanto la naturaleza de estos déficits como factores protectores (e.g., reserva cognitiva) son objeto de estudio. En este estudio se evaluaron las diferencias entre un grupo de 20 adultos mayores sanos y uno de 30 adultos mayores con MCI de la ciudad de Roma, respecto de varias características psicológicas y funciones executivas especialmente relacionadas con la flexibilidad cognitiva y los mecanismos inhibitorios cognitivos y motores. Los resultados indican que el nivel escolar es el factor protector más importante. De particular interés es el resultado en las pruebas de praxia que resulta comprometida en los pacientes con MCI. Generalmente, los trastornos apráxicos se manifiestan en estados avanzados de demencia. Las alteraciones observadas en este estudio podrían ser consideradas como un indicador precoz de demencia
Effects of blood pressure on cognitive performance in aging: a systematic review
Full text linkIntroduction: Cognitive functions play a crucial role in daily functioning. Unfortunately, some cognitive abilities decline in the process of healthy aging. An increasing body of evidence has highlighted the role of lifestyle habits and cardiovascular diseases, such as high blood pressure, in increasing the risk of cognitive decline. Surprisingly, although hypertension is a modifiable risk factor for cerebrovascular damage, the role of hypertension on cognitive impairment development is not still clear. Several key questions remain unresolved, and there are many inconsistent results in studies considering this topic. This review is aimed to systematically analyze the results found by the studies that investigated whether high blood pressure, in both hypertensive and healthy people, is related to cognitive performance. Furthermore, it points to evaluate the role of age in this relationship. Method: The review process was conducted according to the PRISMA statement. Restrictions were made, selecting the studies in English and published in peer‐review journals, including at least one cognitive measure and blood pressure measurement. Studies that included participants with medical conditions, dementia, psychiatric disorders, strokes, and brain injury were excluded. Cross‐sectional and longitudinal studies were analyzed separately. Finally, blood pressure measured at young life (18–39 years), midlife (age 40–64 years), elderly (65–74 years), and old age (≥75 years) were considered. Results: The review allows 68 studies to be selected, which include 154,935 participants. The results provided evidence of an adverse effect of exposure to high blood pressure on cognitive performance. High blood pressure in midlife was linked with poorer cognitive functioning; this evidence was found in cross‐sectional and longitudinal studies. However, this association declines with increasing age and tends to become inconsistent. In older people, the relationship between blood pressure and cognitive performance is non‐linear, highlighting a beneficial effect of high blood pressure on cognition. Conclusions: Despite some limitations, this review showed that cardiovascular and neuro‐cognitive systems do not operate in isolation, but they are related. Blood pressure can be considered an early biomarker of cognitive impairment, and the necessity of early blood pressure measurement and control was underlined
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
FIGURE 24 in The Neotropical genus Ginungagapus gen. nov. (Hesperiidae, Hesperiinae, Moncini): phylogenetic position and taxonomic review
No full textFIGURE 24. Geographical distribution of species of Ginungagapus Carneiro, Mielke & Casagrande, gen. nov.Published as part of Carneiro, Eduardo, Mielke, Olaf H. H. & Casagrande, M. M., 2015, The Neotropical genus Ginungagapus gen. nov. (Hesperiidae, Hesperiinae, Moncini): phylogenetic position and taxonomic review, pp. 196-220 in Zootaxa 3931 (2) on page 205, DOI: 10.11646/zootaxa.3931.2.2, http://zenodo.org/record/23341
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
- …
