1,720,961 research outputs found
Advancing Neuropsychiatric Practice, Training, and Research for 30 Years: ANPA's Committee on Research.
No full textChemical transmitters and modulation of sleep vs. wake promoting neurons
No full textAlthough evidence has suggested a dual role of the basal forebrain (BF) in arousal and sleep generation, the neurotransmitter identity and activity of BF neurons serving these different functions have remained uncertain. Furthermore, few studies have been done to clarify how the wake vs. sleep promoting neurons may be modulated to generate their differential activity and sleep-wake cycle. Using a paradigm of sleep deprivation and sleep recovery and examining c-Fos expression as an indicator of cell activity, we found that across the BF and the adjacent preoptic area, more cells including cholinergic neurons were active during waking than during sleep and thus contribute to generating a waking state. On the other hand, the proportion of c-Fos expressing neurons that were GABAergic was higher during sleep recovery than sleep deprivation, indicating that particular GABAergic cells are involved in generating sleep.Although the posterior hypothalamus has long been known to play a critical role in the maintenance of waking, the neurotransmitter identity of neurons fulfilling this role was not known. Here using c-Fos, we show that Orexin (Orx) neurons are active during waking. On the other hand, we show that co-distributed cells containing melanin concentrating hormone (MCH) are more active during sleep recovery than sleep deprivation, suggesting an opposite role of MCH to that of Orx neurons in sleep vs. waking regulation.Sleep vs. wake promoting cells could be differently modulated by noradrenaline (NA) and accordingly would bear different adrenergic receptors. We found that the majority of GABAergic BF cells expressing c-Fos during sleep bear alpha2 adrenergic receptors (alpha2AAR). They would accordingly be inhibited during waking through these receptors. We also found that many Orx cells in the hypothalamus bear alpha1AAR and thus would be excited by NA during waking. Like the BF GABAergic cells, many MCH neurons were endowed with alpha2AAR and thus would be inhibited during waking.Activation vs. inhibition of sleep or wake-active cells could also be modulated by changes in the availability of cell surface receptors across behavioral states. We show that following sleep deprivation, the presence and the intensity of GABAARs on the BF cholinergic cell membrane were increased. Such activity dependent changes of GABAARs could underlie homeostatic regulation of wake promoting cells across the sleep-waking cycle.These studies identify clearly for the first time the specific neurotransmitter-containing neurons that are active during and thus generative for waking vs. sleep through the BF, the preoptic area and the posterior hypothalamus. They moreover illuminate how by bearing different receptors or changing membrane receptor availability, different cells can be modulated to generate the sleep-waking cycle
Frontotemporal Dementia-related glucose metabolic pattern assessed by FDG-PET
No full textAlzheimer's disease (AD) and Frontotemporal Dementia (FTD) are leading causes of dementia
Neuropsychiatry's Role in the Postacute Sequelae of COVID-19: Report From the American Neuropsychiatric Association Committee on Research.
No full textThe postacute sequelae of COVID-19 infection (PASC), also known as post-COVID condition or "long COVID," refers to symptoms that persist after the initial acute phase of the infection. PASC symptoms may occur in patients who had mild acute disease. On the basis of current data, commonly reported neurological and psychiatric symptoms in PASC include sleep problems, fatigue, cognitive impairment, headache, sensorimotor symptoms, dizziness, anxiety, irritability, and depression. Knowledge from neuropsychiatric sequelae of other viral infections, such as other coronaviruses, provides us with information about the heterogeneity and similarities of neuropsychiatric clinical presentations that may follow viral illnesses over a long period. Several, possibly overlapping, pathophysiological mechanisms have been proposed to explain neuropsychiatric PASC: direct effects of the virus and immunological, vascular, functional, iatrogenic, and other etiologies. The authors present practice considerations for clinicians confronted with the challenge of evaluating and treating patients who have neuropsychiatric PASC. A comprehensive neuropsychiatric approach reviews historical factors, provides an objective assessment of symptoms, carefully considers all potential etiologies, and offers a therapeutic approach aimed at restoring premorbid functioning. Given the currently limited therapeutic options for neuropsychiatric PASC, unless an alternative etiology is identified, treatment should be symptom based and guided by evidence as it emerges
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
Opportunities and challenges in using virtual reality to improve cognitive functioning of the elderly
No full textOver the past decade, researchers have utilized novel technologies to improve the lives of the elderly population. Virtual Reality (VR) is among the most promising platforms that could help the elderly stay cognitively active; However, the extent to which this population is willing to seek out and engage in VR activities remains unclear. In this document, we have discussed our two studies regarding VR and seniors. Our first study is a pilot project including three senior residents of Winnipeg. In this study, we assessed the impact of VR game name “DoVille” on the cognitive capacities of the elderly. We designed a two-week procedure with 20 minutes of VR sessions per day. While the comparison of pre-DoVille and post-DoVille test scores were statistically insignificant, we have gained valuable information about the feasibility and possible challenges of similar projects in the future. Among these issues, we have discussed the eligibility criteria, VR sessions’ setting and length of training sessions for the seniors. The second study is a survey project assessing the attitudes of the elderly toward VR during the COVID-19 pandemic. All senior residents of Manitoba between the ages of 65 and 90 were eligible to participate in the study. The survey was administered online and by phone, and 103 individuals responded to our questionnaire. Our results suggest that a large proportion of elderly individuals have become interested in VR technology as a result of the COVID-19 pandemic. We developed two models for VR use based on the responses. Our model of VR use for communication/interaction could account for approximately 50% of the variance in interest levels in VR, and our model of VR use for cognitive benefits accounted for 35% of the variance. These models included variables such as previous experience with technology, age and gender. In conclusion, these two studies provide us with a better understanding of the elderly’s interest in technology and how we could implement new VR interventions for them in the future.February 202
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
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