88,229 research outputs found
Structural MRI Correlates of Episodic Memory Processes in Parkinson's Disease Without Mild Cognitive Impairment.
BackgroundChanges in episodic memory are common early in Parkinson's disease (PD) and may be a risk factor for future cognitive decline. Although medial temporal lobe (MTL) memory and frontostriatal (FS) executive systems are thought to play different roles in distinct components of episodic memory impairment in PD, no study has investigated whether different aspects of memory functioning are differentially associated with MTL and FS volumes in nondemented patients without mild cognitive impairment (PD-woMCI).ObjectivesThe present study investigated MRI markers of different facets of memory functioning in 48 PD-woMCI patients and 42 controls.MethodsRegional volumes were measured in structures comprising the MTL and FS systems and then correlated with key indices of memory from the California Verbal Learning Test.ResultsIn PD-woMCI patients, memory was impaired only for verbal learning, which was not associated with executive, attention/working memory, or visuospatial functioning. Despite an absence of cortical atrophy, smaller right MTL volumes in patients were associated with poorer verbal learning, long delayed free recall, long delayed cued recall, and recognition memory hits and false positives. Smaller right pars triangularis (inferior frontal) volumes were also associated with poorer long delayed cued recall and recognition memory hits. These relationships were not found in controls.ConclusionsThe findings indicate that MTL volumes are sensitive to subtle changes in almost all facets of memory in PD-woMCI, whereas FS volumes are sensitive only to memory performances in cued-testing formats
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Women can bear a bigger burden: ante- and post-mortem evidence for reserve in the face of tau.
In this study, we aimed to assess whether women are able to withstand more tau before exhibiting verbal memory impairment. Using data from 121 amyloid-β-positive Alzheimer's Disease Neuroimaging Initiative participants, we fit a linear model with Rey Auditory Verbal Learning Test score as the response variable and tau-PET standard uptake value ratio as the predictor and took the residuals as an estimate of verbal memory reserve for each subject. Women demonstrated higher reserve (i.e. residuals), whether the Learning (t = 2.78, P = 0.006) or Delay (t = 2.14, P = 0.03) score from the Rey Auditory Verbal Learning Test was used as a measure of verbal memory ability. To validate these findings, we examined 662 National Alzheimer's Coordinating Center participants with a C2/C3 score (Consortium to Establish a Registry for Alzheimer's Disease) at autopsy. We stratified our National Alzheimer's Coordinating Center sample into Braak 1/2, Braak 3/4 and Braak 5/6 subgroups. Within each subgroup, we compared Logical Memory scores between men and women. Men had worse verbal memory scores within the Braak 1/2 (Logical Memory Immediate: β = -5.960 ± 1.517, P < 0.001, Logical Memory Delay: β = -5.703 ± 1.677, P = 0.002) and Braak 3/4 (Logical Memory Immediate: β = -2.900 ± 0.938, P = 0.002, Logical Memory Delay: β = -2.672 ± 0.955, P = 0.006) subgroups. There were no sex differences in Logical Memory performance within the Braak 5/6 subgroup (Logical Memory Immediate: β = -0.314 ± 0.328, P = 0.34, Logical Memory Delay: β = -0.195 ± 0.287, P = 0.50). Taken together, our results point to a sex-related verbal memory reserve
Neurocognitive impairment is associated with lower health literacy among persons living with HIV infection.
This study sought to determine the effects of HIV-associated neurocognitive disorders (HAND) on health literacy, which encompasses the ability to access, understand, appraise, and apply health-related information. Participants included 56 HIV seropositive individuals, 24 of whom met Frascati criteria for HAND, and 24 seronegative subjects who were comparable on age, education, ethnicity, and oral word reading. Each participant was administered a brief battery of well-validated measures of health literacy, including the Expanded Numeracy Scale (ENS), Newest Vital Sign (NVS), Rapid Estimate of Adult Literacy in Medicine (REALM), and Brief Health Literacy Screen (BHLS). Results revealed significant omnibus differences on the ENS and NVS, which were driven by poorer performance in the HAND group. There were no significant differences on the REALM or the BHLS by HAND status. Among individuals with HAND, lower scores on the NVS were associated with greater severity of neurocognitive dysfunction (e.g., working memory and verbal fluency) and self-reported dependence in activities of daily living. These preliminary findings suggest that HAND hinders both fundamental (i.e., basic knowledge, such as numeracy) and critical (i.e., comprehension and application of healthcare information) health literacy capacities, and therefore may be an important factor in the prevalence of health illiteracy. Health literacy-focused intervention may play an important role in the treatment and health trajectories among persons living with HIV infection
Semantic Sentiment Analysis of Twitter Data
Internet and the proliferation of smart mobile devices have changed the way
information is created, shared, and spreads, e.g., microblogs such as Twitter,
weblogs such as LiveJournal, social networks such as Facebook, and instant
messengers such as Skype and WhatsApp are now commonly used to share thoughts
and opinions about anything in the surrounding world. This has resulted in the
proliferation of social media content, thus creating new opportunities to study
public opinion at a scale that was never possible before. Naturally, this
abundance of data has quickly attracted business and research interest from
various fields including marketing, political science, and social studies,
among many others, which are interested in questions like these: Do people like
the new Apple Watch? Do Americans support ObamaCare? How do Scottish feel about
the Brexit? Answering these questions requires studying the sentiment of
opinions people express in social media, which has given rise to the fast
growth of the field of sentiment analysis in social media, with Twitter being
especially popular for research due to its scale, representativeness, variety
of topics discussed, as well as ease of public access to its messages. Here we
present an overview of work on sentiment analysis on Twitter.Comment: Microblog sentiment analysis; Twitter opinion mining; In the
Encyclopedia on Social Network Analysis and Mining (ESNAM), Second edition.
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Novel cruzain inhibitors for the treatment of Chagas' disease.
The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas' disease, affects millions of individuals and continues to be an important global health concern. The poor efficacy and unfavorable side effects of current treatments necessitate novel therapeutics. Cruzain, the major cysteine protease of T. cruzi, is one potential novel target. Recent advances in a class of vinyl sulfone inhibitors are encouraging; however, as most potential therapeutics fail in clinical trials and both disease progression and resistance call for combination therapy with several drugs, the identification of additional classes of inhibitory molecules is essential. Using an exhaustive virtual-screening and experimental validation approach, we identify several additional small-molecule cruzain inhibitors. Further optimization of these chemical scaffolds could lead to the development of novel drugs useful in the treatment of Chagas' disease
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Genetic Toolkit for Assessment and Prediction of Population-Level Impacts of Bridge Construction on Birds
Recent studies have highlighted alarming rates of declines in bird populations across the country. The State of California is home to over 650 resident and migrant avian species. Legislation for protecting these species has existed for over a century now, yet tools for identifying populations and understanding seasonal movement remain limited. Recently, genetic and genomic tools have provided a method for understanding population structure, allowing for more informed delineation of management units. The goal of this project was to create a genetic toolkit for identifying breeding populations and assigning individuals to those populations. Ultimately, such tools could be used to assess population-level impacts when there are conflicts with birds at infrastructure construction sites. As a test case, we sequenced entire genomes for 40 individual Anna’s hummingbirds (Calypte anna) from across the state. Based on this initial data, we found low levels of differentiation between sampled locations, suggesting that C. anna in California are not subdivided into different population units. However, there was a weak signal of geography suggesting there may be localized genetic differences in a small proportion of the genome. Follow-up work will focus on a broader sampling across the state of California to clarify any possible population subdivision or geographical patterns of differentiation.View the NCST Project Webpag
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Environmental public health tracking of childhood asthma using California health interview survey, traffic, and outdoor air pollution data.
BackgroundDespite extensive evidence that air pollution affects childhood asthma, state-level and national-level tracking of asthma outcomes in relation to air pollution is limited.ObjectivesOur goals were to evaluate the feasibility of linking the 2001 California Health Interview Survey (CHIS), air monitoring, and traffic data; estimate associations between traffic density (TD) or outdoor air pollutant concentrations and childhood asthma morbidity; and evaluate the usefulness of such databases, linkages, and analyses to Environmental Public Health Tracking (EPHT).MethodsWe estimated TD within 500 feet of residential cross-streets of respondents and annual average pollutant concentrations based on monitoring station measurements. We used logistic regression to examine associations with reported asthma symptoms and emergency department (ED) visits/hospitalizations.ResultsAssignment of TD and air pollution exposures for cross-streets was successful for 82% of children with asthma in Los Angeles and San Diego, California, Counties. Children with asthma living in high ozone areas and areas with high concentrations of particulate matter < 10 microm in aerodynamic diameter experienced symptoms more frequently, and those living close to heavy traffic reported more ED visits/hospitalizations. The advantages of the CHIS for asthma EPHT include a large and representative sample, biennial data collection, and ascertainment of important socio-demographic and residential address information. Disadvantages are its cross-sectional design, reliance on parental reports of diagnoses and symptoms, and lack of information on some potential confounders.ConclusionsDespite limitations, the CHIS provides a useful framework for examining air pollution and childhood asthma morbidity in support of EPHT, especially because later surveys address some noted gaps. We plan to employ CHIS 2003 and 2005 data and novel exposure assessment methods to re-examine the questions raised here
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