129 research outputs found
Applying Deep Learning to Predicting Dementia and Mild Cognitive Impairment
Dementia has a large negative impact on the global healthcare and society. Diagnosis is rather challenging as there is no standardised test. The purpose of this paper is to conduct an analysis on ADNI data and determine its effectiveness for building classification models to differentiate the categories Cognitively Normal (CN), Mild Cognitive Impairment (MCI), and Dementia (DEM), based on tuning three Deep Learning models: two Multi-Layer Perceptron (MLP1 and MLP2) models and a Convolutional Bidirectional Long Short-Term Memory (ConvBLSTM) model. The results show that the MLP1 and MLP2 models accurately distinguish the DEM, MCI and CN classes, with accuracies as high as 0.86 (SD 0.01). The ConvBLSTM model was slightly less accurate but was explored in view of comparisons with the MLP models, and for future extensions of this work that will take advantage of time-related information. Although the performance of ConvBLSTM model was negatively impacted by a lack of visit code data, opportunities were identified for improvement, particularly in terms of pre-processing
Educational Homogamy Lowers the Odds of Reproductive Failure
Assortative mating based on education is a common phenomenon. We investigated whether it affected parameters of reproductive performance such as childlessness, offspring number and age at first marriage. On the basis of the US census from 1980 (n = 670,631 married US couples), we find that the proportion of childless individuals is usually minimal in women married to a husband of the same educational level. This holds particularly true in the highest and the lowest educated women. Educational homogamy is also associated with a lower average age at first marriage. No obvious effect of educational homogamy on a woman's average offspring number is found, where mean offspring number generally increases both with decreasing woman's and decreasing husband's educational attainment. We conclude that educational homogamy reduces the likelihood of reproductive failure
Awareness of vaccination status and its predictors among working people in Switzerland
BACKGROUND: Adult vaccination status may be difficult to obtain, often requiring providers to rely on individual patient recall. To determine vaccination status awareness and the sociodemographic predictors of awareness for tetanus, hepatitis A and B, tick born encephalitis (TBE) and influenza vaccination. METHODS: Multivariate analyses were used to evaluate a questionnaire survey of 10 321 employees (4070 women and 6251 men aged 15–72 years) of two companies in Switzerland. RESULTS: Among 10 321 respondents, 75.5% reported knowing their tetanus vaccination status, 64.1% hepatitis A, 61.1% hepatitis B, 64.3% TBE and 71.9% influenza. Between 1 in 4 and 1 in 3 employees were not aware of their vaccination status. Differences in awareness for the five vaccinations considered correlated with gender and language. These differences persisted in multivariate analyses. CONCLUSION: Women employees, German-speaking employees and employees who paid more attention to their diet were more often aware of their vaccination status. A more reliable and readily accessible data source for vaccination status is needed in order to capitalize on opportunities to update vaccinations among Swiss employees
How Humans Differ from Other Animals in Their Levels of Morphological Variation
Animal species come in many shapes and sizes, as do the individuals and populations that make up each species. To us, humans might seem to show particularly high levels of morphological variation, but perhaps this perception is simply based on enhanced recognition of individual conspecifics relative to individual heterospecifics. We here more objectively ask how humans compare to other animals in terms of body size variation. We quantitatively compare levels of variation in body length (height) and mass within and among 99 human populations and 848 animal populations (210 species). We find that humans show low levels of within-population body height variation in comparison to body length variation in other animals. Humans do not, however, show distinctive levels of within-population body mass variation, nor of among-population body height or mass variation. These results are consistent with the idea that natural and sexual selection have reduced human height variation within populations, while maintaining it among populations. We therefore hypothesize that humans have evolved on a rugged adaptive landscape with strong selection for body height optima that differ among locations
Expression profiling identifies novel candidate genes for ethanol sensitivity QTLs
The Inbred Long Sleep (ILS) and Inbred Short Sleep (ISS) mouse strains have a 16-fold difference in duration of loss of the righting response (LORR) following administration of a sedative dose of ethanol. Four quantitative trait loci (QTLs) have been mapped in these strains for this trait. Underlying each of these QTLs must be one or more genetic differences (polymorphisms in either gene coding or regulatory regions) influencing ethanol sensitivity. Because prior studies have tended to focus on differences in coding regions, genome-wide expression profiling in cerebellum was used here to identify candidate genes for regulatory region differences in these two strains. Fifteen differentially expressed genes were found that map to the QTL regions and polymorphisms were identified in the promoter regions of four of these genes by direct sequencing of ILS and ISS genomic DNA. Polymorphisms in the promoters of three of these genes, Slc22a4, Rassf2, and Tax1bp3, disrupt putative transcription factor binding sites. Slc22a4 and another candidate, Xrcc5, have human orthologs that map to genomic regions associated with human ethanol sensitivity in genetic linkage studies. These genes represent novel candidates for the LORR phenotype and provide new targets for future studies into the neuronal processes underlying ethanol sensitivity
Convergence in the physical appearance of spouses
This study attempted to determine whether people who live with each other for a long period of time grow physically similar in their facial features. Photographs of couples when they were first married and 25 years later were judged for physical similarity and for the likelihood that they were married. The results showed that there is indeed an increase in apparent similarity after 25 years of cohabitation. Moreover, increase in resemblance was associated with greater reported marital happiness. Among the explanations of this phenomenon that were examined, one based on a theory of emotional efference emerged as promising. This theory proposes that emotional processes produce vascular changes that are, in part, regulated by facial musculature. The facial muscles are said to act as ligatures on veins and arteries, and they thereby are able to divert blood from, or direct blood to, the brain. An implication of the vascular theory of emotional efference is that habitual use of facial musculature may permanently affect the physical features of the face. The implication holds further that two people who live with each other for a longer period of time, by virtue of repeated empathic mimicry, would grow physically similar in their facial features. Kin resemblance, therefore, may not be simply a matter of common genes but also a matter of prolonged social contact.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45361/1/11031_2004_Article_BF00992848.pd
Evolution of Assortative Mating in a Population Expressing Dominance
In this article, we study the influence of dominance on the evolution of
assortative mating. We perform a population-genetic analysis of a two-locus
two-allele model. We consider a quantitative trait that is under a mixture
of frequency-independent stabilizing selection and density- and frequency-dependent
selection caused by intraspecific competition for a continuum of resources.
The trait is determined by a single (ecological) locus and expresses intermediate
dominance. The second (modifier) locus determines the degree of assortative
mating, which is expressed in females only. Assortative mating is based on
similarities in the quantitative trait (‘magic trait’ model).
Analytical conditions for the invasion of assortment modifiers are derived
in the limit of weak selection and weak assortment. For the full model, extensive
numerical iterations are performed to study the global dynamics. This allows
us to gain a better understanding of the interaction of the different selective
forces. Remarkably, depending on the size of modifier effects, dominance can
have different effects on the evolution of assortment. We show that dominance
hinders the evolution of assortment if modifier effects are small, but promotes
it if modifier effects are large. These findings differ from those in previous
work based on adaptive dynamics
Dopamine Receptor Activation Increases HIV Entry into Primary Human Macrophages
Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers
Plötzliche Todesfälle an Schweizer Volksläufen 1978-1987: eine epidemiologisch-pathologische Studie
Between 1984 and 1987 there were 7 cases of sudden cardiac death during organized mass runs in Switzerland, and between 1978 and 1987 there were 3 cases during the nine largest mass running events (total 8 cases of sudden death during the race). Based on numbers of participants in all events 1984-1987, or in the nine largest events 1978-1987, an incidence of 1 sudden death per 129,500 hrs. of running (95% confidence interval 1/62,500-1/263,000 hrs.), or 1 sudden death per 117,000 hrs. of running (1/45,000-1/311,000 hrs.) respectively, was estimated. This estimate is higher than the rate of 1 sudden death per 396,000 hrs. of noncompetitive jogging found in a study from the United States (Thompson et al.: J. Amer. med. Ass. 1982; 247: 2535-2538). The Swiss incidence of sudden cardiac death during organized mass runs was 50 to 1000 times higher than the incidence expected by chance alone (as estimated from national death register data). All 8 cases of the study were men, the younger four aged 23 yrs. on average (range 20-31 yrs.), the older four aged 49 yrs. (46-53 yrs.). Autopsy in three of the younger men identified hypertrophic cardiomyopathy in one instance whereas in the two other cases no plausible cause of death could be found. The two autopsies performed in older men both showed severe coronary heart disease. Only in 1 case out of the 8 were possible prodromal symptoms of the subsequent death, such as fatigue and nausea, observed, and the average prevalence of known cardiovascular risk factors was low. None of the 8 runners dying suddenly was completely untrained, but 6 out of 8 had only modest running experience, i.e. a low number of years of running. This study confirms that there is probably a clearly increased risk of sudden death during running events with a competitive character, but this acute elevation of risk should probably not be overstated in view of both its very low population - attributable risk and the important potential of regular exercise for overall coronary risk reduction and health promotion
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