1,005 research outputs found
Can MRI T1 be used to detect early changes in 5xFAD Alzheimer’s mouse brain?
In the present study, we have tested whether MRI T1 relaxation time is a sensitive marker to detect early stages of amyloidosis and gliosis in the young 5xFAD transgenic mouse, a well-established animal model for Alzheimer's disease.5xFAD and wild-type mice were imaged in a 4.7 T Varian horizontal bore MRI system to generate T1 quantitative maps using the spin-echo multi-slice sequence. Following immunostaining for glial fibrillary acidic protein, Iba-1, and amyloid-β, T1 and area fraction of staining were quantified in the posterior parietal and primary somatosensory cortex and corpus callosum.In comparison with age-matched wild-type mice, we observed first signs of amyloidosis in 2.5-month-old 5xFAD mice, and development of gliosis in 5-month-old 5xFAD mice. In contrast, MRI T1 relaxation times of young, i.e., 2.5- and 5-month-old, 5xFAD mice were not significantly different to those of age-matched wild-type controls. Furthermore, although disease progression was detectable by increased amyloid-β load in the brain of 5-month-old 5xFAD mice compared with 2.5-month-old 5xFAD mice, MRI T1 relaxation time did not change.In summary, our data suggest that MRI T1 relaxation time is neither a sensitive measure of disease onset nor progression at early stages in the 5xFAD mouse transgenic mouse model
User Feedback on Celebratory Technology Model for Reducing Stigma
Social stigma is a complex manifestation that affects humanity, particularly individuals with disabilities and other marginalized groups, including those with physical, cognitive, and emotional conditions. Society often judges these individuals\u27 interactions with the world, and many technologies designed to assist those with disabilities attempt to change their daily interactions and behaviors. Nonetheless, when the emphasis is placed on validating disabled identities, there is a potential for it to be seen as inspiration porn. This approach might inadvertently reduce inclusivity and do little to challenge negative stereotypes; it can also lead to the objectification of individuals with disabilities. Therefore, this project presents the notion of Celebratory Technologies for Neurodiversity, which aims to promote inclusivity and empower stigmatized individuals. This concept strives to level the playing field, rather than serving as a solitary source of inspiration for nondisabled observers. In this context, a Figma diagram and a user survey were created using Maze to gather feedback from students at Chapman University on the concept of Celebratory Technology. This valuable input will help refine and develop Celebratory Technologies for Neurodiversity, drawing upon social change frameworks, principles of the Neurodiversity movement, and insights from marginalized groups on how to reduce stigma. The Figma prototype introduces Celebratory Technology in the form of a colorful visual representation of the participants’ answers to a personality survey, with the goal of showcasing users from different backgrounds and identities in an abstract way. This in turn has a goal of celebrating uniqueness and individuality without implementing labels or alienation. This project serves as a preliminary step in introducing Celebratory Technology and aims to expand the conversation of ways to mitigate social stigma. Initial suggestions for creating supportive Celebratory Technologies for Neurodiversity are provided in this project
Incorporating chemical signalling factors into cell-based models of growing epithelial tissues
In this paper we present a comprehensive computational framework within which the effects of chemical signalling factors on growing epithelial tissues can be studied. The method incorporates a vertex-based cell model, in conjunction with a solver for the governing chemical equations. The vertex model provides a natural mesh for the finite element method (FEM), with node movements determined by force laws. The arbitrary Lagrangian–Eulerian formulation is adopted to account for domain movement between iterations. The effects of cell proliferation and junctional rearrangements on the mesh are also examined. By implementing refinements of the mesh we show that the finite element (FE) approximation converges towards an accurate numerical solution. The potential utility of the system is demonstrated in the context of Decapentaplegic (Dpp), a morphogen which plays a crucial role in development of the Drosophila imaginal wing disc. Despite the presence of a Dpp gradient, growth is uniform across the wing disc. We make the growth rate of cells dependent on Dpp concentration and show that the number of proliferation events increases in regions of high concentration. This allows hypotheses regarding mechanisms of growth control to be rigorously tested. The method we describe may be adapted to a range of potential application areas, and to other cell-based models with designated node movements, to accurately probe the role of morphogens in epithelial tissues
Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort
Cocoa flavanols (CF) positively influence physiological processes in ways that suggest their consumption may improve aspects of cognitive function. This study investigated the acute cognitive and subjective effects of CF consumption during sustained mental demand. In this randomized, controlled, double-blinded, balanced, three period crossover trial 30 healthy adults consumed drinks containing 520 mg, 994 mg CF and a matched control, with a three-day washout between drinks. Assessments included the state anxiety inventory and repeated 10-min cycles of a Cognitive Demand Battery comprising of two serial subtraction tasks (Serial Threes and Serial Sevens), a Rapid Visual Information Processing (RVIP) task and a mental fatigue scale, over the course of 1 h. Consumption of both 520 mg and 994 mg CF significantly improved Serial Threes performance. The 994 mg CF beverage significantly speeded RVIP responses but also resulted in more errors during Serial Sevens. Increases in self-reported mental fatigue were significantly attenuated by the consumption of the 520 mg CF beverage only. This is the first report of acute cognitive improvements following CF consumption in healthy adults. While the mechanisms underlying the effects are unknown they may be related to known effects of CF on endothelial function and blood flow
Time Distribution of the Onset of Chest Pain in Subjects with Acute ST-Elevation Myocardial Infarction: An Eight-Year, Single-Center Study in China
Objective: The objective of this study was to explore the time distribution patterns of the onset of chest pain in subjects with acute ST-elevation myocardial infarction in a Chinese population. Methods: A total of 1467 patients with acute ST-elevation myocardial infarction were enrolled from 2003 to 2010. The hourly, daily, monthly, seasonal and day-of-week fluctuations in the prevalence of acute ST-elevation myocardial infarction were analyzed. Results: A peak was found between the morning hours of 07:31 and 08:30. A second peak was observed between 14:31 and 15:30, and a third peak was found between 23:31 and 00:30 (p,0.001). The monthly maximum was recorded in November and the minimum was in April (p,0.001). The number of daily cases was greatest in autumn and lowest in the spring (p = 0.001). Day-of-the-week variations of ST-elevation acute myocardial infarction were not found, except in patients more than 75-years-old. Conclusions: Periodic variations in the frequency of ST-elevation acute myocardial infarction in Chinese patients showed significant differences with regard to diurnal, monthly and seasonal patterns. The exact mechanisms underlying thes
Characteristics of patients with venous thromboembolism and atrial fibrillation in Venezuela
<p>Abstract</p> <p>Background</p> <p>Studies describing venous thromboembolic event (VTEE) and atrial fibrillation (AF) in South American populations are limited. The aim of this cross-sectional study was to describe the characteristics of Venezuelan patients admitted and treated for these conditions.</p> <p>Methods</p> <p>A retrospective medical record review of 1397 consecutive patients admitted to three private hospitals or clinics between January 2000 and December 2005 was performed. Data was collected on demographics, anthropometrics, hospital visit, comorbidities and treatment.</p> <p>Results</p> <p>Among 401 VTEE and 996 AF patients, men were more likely to have AF (58%) while more women experienced a VTEE (58%). Most patients were admitted via the emergency room (87%) and had only one event during the study period (83%). Common comorbidities included hypertension (46%), heart failure (17%), diabetes (12%) and congestive heart failure (11%). Characteristics of Venezuelan patients with VTEE and AF are similar to that reported in the literature for other populations.</p> <p>Conclusions</p> <p>These results provide background characteristics for future studies assessing risk factors for AF and VTEE in South American populations.</p
The Context of Temporal Processing Is Represented in the Multidimensional Relationships between Timing Tasks
In the present study we determined the performance interrelations of ten different tasks that involved the processing of temporal intervals in the subsecond range, using multidimensional analyses. Twenty human subjects executed the following explicit timing tasks: interval categorization and discrimination (perceptual tasks), and single and multiple interval tapping (production tasks). In addition, the subjects performed a continuous circle-drawing task that has been considered an implicit timing paradigm, since time is an emergent property of the produced spatial trajectory. All tasks could be also classified as single or multiple interval paradigms. Auditory or visual markers were used to define the intervals. Performance variability, a measure that reflects the temporal and non-temporal processes for each task, was used to construct a dissimilarity matrix that quantifies the distances between pairs of tasks. Hierarchical clustering and multidimensional scaling were carried out on the dissimilarity matrix, and the results showed a prominent segregation of explicit and implicit timing tasks, and a clear grouping between single and multiple interval paradigms. In contrast, other variables such as the marker modality were not as crucial to explain the performance between tasks. Thus, using this methodology we revealed a probable functional arrangement of neural systems engaged during different timing behaviors
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