981 research outputs found
Limbic Tract Integrity Contributes to Pattern Separation Performance Across the Lifespan.
Accurate memory for discrete events is thought to rely on pattern separation to orthogonalize the representations of similar events. Previously, we reported that a behavioral index of pattern separation was correlated with activity in the hippocampus (dentate gyrus, CA3) and with integrity of the perforant path, which provides input to the hippocampus. If the hippocampus operates as part of a broader neural network, however, pattern separation would likely also relate to integrity of limbic tracts (fornix, cingulum bundle, and uncinate fasciculus) that connect the hippocampus to distributed brain regions. In this study, healthy adults (20-89 years) underwent diffusion tensor imaging and completed the Behavioral Pattern Separation Task-Object Version (BPS-O) and Rey Auditory Verbal Learning Test (RAVLT). After controlling for global effects of brain aging, exploratory skeleton-wise and targeted tractography analyses revealed that fornix integrity (fractional anisotropy, mean diffusivity, and radial diffusivity; but not mode) was significantly related to pattern separation (measured using BPS-O and RAVLT tasks), but not to recognition memory. These data suggest that hippocampal disconnection, via individual- and age-related differences in limbic tract integrity, contributes to pattern separation performance. Extending our earlier work, these results also support the notion that pattern separation relies on broad neural networks interconnecting the hippocampus
The distribution of pre-Norman sculpture in South-West Scotland : provenance, ornament and regional groups.
In 4 volsSIGLEAvailable from British Library Document Supply Centre- DSC:D175400 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Solar Magnetic Tracking. IV. The Death of Magnetic Features
The removal of magnetic flux from the quiet-sun photosphere is important for
maintaining the statistical steady-state of the magnetic field there, for
determining the magnetic flux budget of the Sun, and for estimating the rate of
energy injected into the upper solar atmosphere. Magnetic feature death is a
measurable proxy for the removal of detectable flux. We used the SWAMIS feature
tracking code to understand how nearly 20000 detected magnetic features die in
an hour-long sequence of Hinode/SOT/NFI magnetograms of a region of quiet Sun.
Of the feature deaths that remove visible magnetic flux from the photosphere,
the vast majority do so by a process that merely disperses the
previously-detected flux so that it is too small and too weak to be detected.
The behavior of the ensemble average of these dispersals is not consistent with
a model of simple planar diffusion, suggesting that the dispersal is
constrained by the evolving photospheric velocity field. We introduce the
concept of the partial lifetime of magnetic features, and show that the partial
lifetime due to Cancellation of magnetic flux, 22 h, is 3 times slower than
previous measurements of the flux turnover time. This indicates that prior
feature-based estimates of the flux replacement time may be too short, in
contrast with the tendency for this quantity to decrease as resolution and
instrumentation have improved. This suggests that dispersal of flux to smaller
scales is more important for the replacement of magnetic fields in the quiet
Sun than observed bipolar cancellation. We conclude that processes on spatial
scales smaller than those visible to Hinode dominate the processes of flux
emergence and cancellation, and therefore also the quantity of magnetic flux
that threads the photosphere.Comment: Accepted by Ap
Mixed-monolayer glyconanoparticles for the detection of cholera toxin by surface enhanced raman spectroscopy
The same interactions that a pathogen uses for establishment in a host can be exploited in its detection. The carbohydrates comprising the intestinal cell surface GM1-ganglioside, are targeted by vibrio cholerae via the lectin, cholera toxin, to initiate infection. We report on the preparation of mixed-monolayer, carbohydrate-coated silver nanoparticles (glyconanoparticles) for the sensitive (56 ng/mL), low volume detection of cholera toxin B-subunit (CTB) in synthetic freshwater samples and in 5 minutes by surface enhanced Raman spectroscopy (SERS). The detection limit falls within the recommended detection range and matches WHO approved test limits. PEGylated galactose and sialic acid are added in a specific ratio to coat the particles in GM1-ganglioside mimics for interaction with CTB and display a synergic effect greater than either glycan alone. This demonstrates the first use of a mixed-monolayer glyconanoparticle which mimics the GM1 ligand, allowing selective interaction with CTB
Valuation of Child Behavioral Problems from the Perspective of US Adults
To assess preferences between child behavioral problems and estimate their value on a quality-adjusted life year (QALYs) scale
User-centred design using Gamestorming
© 2016 IMIA and IOS Press. User-centered design (UX) is becoming a standard in software engineering and has tremendous potential in healthcare. The purpose of this tutorial will be to demonstrate and provide participants with practice in usercentred design methods that involve 'Gamestorming', a form of brainstorming where 'the rules of life are temporarily suspended'. Participants will learn and apply gamestorming methods including persona development via empathy mapping and methods to translate artefacts derived from participatory design sessions into functional and design requirements
Increased prevalence of precancerous changes in relatives of gastric cancer patients: critical role of H. pylori
Background & Aims:Helicobacter pylori is believed to predispose to gastric cancer by inducing gastric atrophy and hypochlorhydria. First-degree relatives of patients with gastric cancer have an increased risk of developing gastric cancer. The aim of this study was to determine the prevalence of atrophy and hypochlorhydria and their association with H. pylori infection in first-degree relatives of patients with gastric cancer. Methods:H. pylori status, gastric secretory function, and gastric histology were studied in 100 first-degree relatives of patients with noncardia gastric cancer and compared with those of controls with no family history of this cancer. Results: Compared with healthy controls, relatives of patients with gastric cancer had a higher prevalence of hypochlorhydria (27% vs. 3%) but a similar prevalence of H. pylori infection (63% vs. 64%). Relatives of cancer patients also had a higher prevalence of atrophy (34%) than patients with nonulcer dyspepsia (5%) matched for H. pylori prevalence. Among the relatives of cancer patients, the prevalence of atrophy and hypochlorhydria was increased only in those with evidence of H. pylori infection, was greater in relatives of patients with familial cancer than in relatives of sporadic cancer index patients, and increased with age. Eradication of H. pylori infection produced resolution of the gastric inflammation in each subject and resolution of hypochlorhydria and atrophy in 50% of the subjects. Conclusions: Relatives of patients with gastric cancer have an increased prevalence of precancerous gastric abnormalities, but this increase is confined to those with H. pylori infection. Consequently, prophylactic eradication of the infection should be offered to such subjects
Evidence-Based intervention (Ebi) Mapping: a Systematic approach to Understanding the Components and Logic of Ebis
BACKGROUND: Despite the development of numerous evidence-based interventions (EBIs), many go unused in practice. Hesitations to use existing EBIs may be due to a lack of understanding about EBI components and what it would take to adapt it or implement it as designed. to improve the use of EBIs, program planners need to understand their goals, core components, and mechanisms of action. This paper presents EBI Mapping, a systematic approach based on Intervention Mapping, that can be used to understand and clearly describe EBIs, and help planners put them into practice.
METHODS: We describe EBI Mapping tasks and provide an example of the process. EBI Mapping uses principles from Intervention Mapping, a systematic framework for planning multilevel health promotion interventions. EBI Mapping applies the Intervention Mapping steps retrospectively to help planners understand an existing EBI (rather than plan a new one). We explain each EBI Mapping task and demonstrate the process using the VERB Summer Scorecard (VSS), a multi-level community-based intervention to improve youth physical activity.
RESULTS: EBI Mapping tasks are: 1) document EBI materials and activities, and their audiences, 2) identify the EBI goals, content, and mechanisms of action, 3) identify the theoretical change methods and practical applications of those methods, 4) describe design features and delivery channels, and 5) describe the implementers and their tasks, implementation strategies, and needed resources. By applying the EBI Mapping tasks, we created a logic model for the VSS intervention. The VSS logic model specifies the links between behavior change methods, practical applications, and determinants for both the at-risk population and environmental change agents. The logic model also links the respective determinants to the desired outcomes including the health behavior and environmental conditions to improve the health outcome in the at-risk population.
CONCLUSIONS: EBI Mapping helps program planners understand the components and logic of an EBI. This information is important for selecting, adapting, and scaling-up EBIs. Accelerating and improving the use of existing EBIs can reduce the research-to-practice gap and improve population health
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