2,800 research outputs found
Digital literacy linked to engagement and psychological benefits among breast cancer survivors in Internet-based peer support groups
© 2019 John Wiley & Sons Ltd Objective: Internet-based peer support groups (ISGs) represent an innovative, scalable approach to addressing information and support needs of cancer survivors. However, this innovation may not benefit survivors equally due to population variance in digital literacy. This study examined how digital literacy influences level of engagement in and psychological benefits from participating in ISGs for breast cancer (N = 183). Methods: Secondary analysis of data from a randomised trial of ISGs that included behavioural measures of engagement, subjective ratings and psychological distress symptoms. Results: Digital literacy was positively related to education level (p =.005). Relative to women with high digital literacy, those with lower digital literacy were more likely to report difficulties using the ISG and to value the user's guide and facilitator assistance (all p's <.05). Digital literacy was negatively correlated with computer anxiety pre-intervention, distress before and after online chat during the intervention and post-intervention depressive symptoms (all p's <.05). Conclusion: Low digital literacy is associated with computer anxiety and barriers to ISG use, as well as distress during and after ISG use. Digital literacy must be taken into account when designing or delivering innovative digital interventions for cancer survivors
Effect of FK 506 on spontaneous diabetes in BB rats
From days 30-120 after birth, 59 BB rats were treated with water (n = 20) or FK 506 in intragastric doses of 1 mg·kg-1·day-1 (n = 19) or 2 mg·kg-1·day-1 (n = 20). Diabetes developed in 75, 15, and 0% of the 3 groups, respectively. Animals protected from diabetes by FK 506 had normal intraperitoneal glucose tolerance tests, virtual absence histopathologically of autoimmune insulitis, and normal pancreatic insulin content. Forty-five to 75 days after stopping FK 506, ∼75% of the rats that were diabetes free at 120 days remained so
Pathogenic alpha-synuclein aggregates preferentially bind to mitochondria and affect cellular respiration
Abstract
Misfolded alpha-synuclein (αSyn) is a major constituent of Lewy bodies and Lewy neurites, which are pathological hallmarks of Parkinson’s disease (PD). The contribution of αSyn to PD is well established, but the detailed mechanism remains obscure. Using a model in which αSyn aggregation in primary neurons was seeded by exogenously added, preformed αSyn amyloid fibrils (PFF), we found that a majority of pathogenic αSyn (indicated by serine 129 phosphorylated αSyn, ps-αSyn) was membrane-bound and associated with mitochondria. In contrast, only a minuscule amount of physiological αSyn was mitochondrial bound. In vitro, αSyn PFF displayed a stronger binding to purified mitochondria than did αSyn monomer, revealing a preferential mitochondria binding by aggregated αSyn. This selective mitochondrial ps-αSyn accumulation was confirmed in other neuronal and animal αSyn aggregation models that do not require exogenously added PFF and, more importantly, in postmortem brain tissues of patients suffering from PD and other neurodegenerative diseases with αSyn aggregation (α-synucleinopathies). We also showed that the mitochondrial ps-αSyn accumulation was accompanied by defects in cellular respiration in primary neurons, suggesting a link to mitochondrial dysfunction. Together, our results show that, contrary to physiological αSyn, pathogenic αSyn aggregates preferentially bind to mitochondria, indicating mitochondrial dysfunction as the common downstream mechanism for α-synucleinopathies. Our findings suggest a plausible model explaining the formation and the peculiar morphology of Lewy body and reveal that disrupting the interaction between ps-αSyn and the mitochondria is a therapeutic target for α-synucleinopathies.https://deepblue.lib.umich.edu/bitstream/2027.42/148288/1/40478_2019_Article_696.pd
Epstein-Barr virus transcription factor Zta acts through distal regulatory elements to directly control cellular gene expression
Lytic replication of the human gamma herpes virus Epstein-Barr virus (EBV) is an essential prerequisite for the spread of the virus. Differential regulation of a limited number of cellular genes has been reported in B-cells during the viral lytic replication cycle. We asked whether a viral bZIP transcription factor, Zta (BZLF1, ZEBRA, EB1), drives some of these changes. Using genome-wide chromatin immunoprecipitation coupled to next-generation DNA sequencing (ChIP-seq) we established a map of Zta interactions across the human genome. Using sensitive transcriptome analyses we identified 2263 cellular genes whose expression is significantly changed during the EBV lytic replication cycle. Zta binds 278 of the regulated genes and the distribution of binding sites shows that Zta binds mostly to sites that are distal to transcription start sites. This differs from the prevailing view that Zta activates viral genes by binding exclusively at promoter elements. We show that a synthetic Zta binding element confers Zta regulation at a distance and that distal Zta binding sites from cellular genes can confer Zta-mediated regulation on a heterologous promoter. This leads us to propose that Zta directly reprograms the expression of cellular genes through distal elements
Scaling Laws in Human Language
Zipf's law on word frequency is observed in English, French, Spanish,
Italian, and so on, yet it does not hold for Chinese, Japanese or Korean
characters. A model for writing process is proposed to explain the above
difference, which takes into account the effects of finite vocabulary size.
Experiments, simulations and analytical solution agree well with each other.
The results show that the frequency distribution follows a power law with
exponent being equal to 1, at which the corresponding Zipf's exponent diverges.
Actually, the distribution obeys exponential form in the Zipf's plot. Deviating
from the Heaps' law, the number of distinct words grows with the text length in
three stages: It grows linearly in the beginning, then turns to a logarithmical
form, and eventually saturates. This work refines previous understanding about
Zipf's law and Heaps' law in language systems.Comment: 6 pages, 4 figure
Fast flowing populations are not well mixed
In evolutionary dynamics, well-mixed populations are almost always associated
with all-to-all interactions; mathematical models are based on complete graphs.
In most cases, these models do not predict fixation probabilities in groups of
individuals mixed by flows. We propose an analytical description in the
fast-flow limit. This approach is valid for processes with global and local
selection, and accurately predicts the suppression of selection as competition
becomes more local. It provides a modelling tool for biological or social
systems with individuals in motion.Comment: 19 pages, 8 figure
Design and implementation of a low-cost mechatronic shoe for biomechanical analysis of the human locomotion
In this paper the development of a low-cost and easy wearable mechatronic system for the measurement of ground reaction forces (GRF) for the biomechanical analysis of the human locomotion is presented. The system consists of an insole, a conditioning device for the signals produced by the sensors applied to the insole and a data acquisition system connected to a USB portable storage. The sensors applied to the insole can measure the reaction forces in the horizontal and vertical directions during locomotion. The prototype was validated by comparing the data from the sensors with the values obtained using a force platform
Statistical Laws Governing Fluctuations in Word Use from Word Birth to Word Death
We analyze the dynamic properties of 10^7 words recorded in English, Spanish
and Hebrew over the period 1800--2008 in order to gain insight into the
coevolution of language and culture. We report language independent patterns
useful as benchmarks for theoretical models of language evolution. A
significantly decreasing (increasing) trend in the birth (death) rate of words
indicates a recent shift in the selection laws governing word use. For new
words, we observe a peak in the growth-rate fluctuations around 40 years after
introduction, consistent with the typical entry time into standard dictionaries
and the human generational timescale. Pronounced changes in the dynamics of
language during periods of war shows that word correlations, occurring across
time and between words, are largely influenced by coevolutionary social,
technological, and political factors. We quantify cultural memory by analyzing
the long-term correlations in the use of individual words using detrended
fluctuation analysis.Comment: Version 1: 31 pages, 17 figures, 3 tables. Version 2 is streamlined,
eliminates substantial material and incorporates referee comments: 19 pages,
14 figures, 3 table
Census politics in deeply divided societies
Population censuses in societies that are deeply divided along ethnic, religious or linguistic lines can be sensitive affairs – particularly where political settlements seek to maintain peace through the proportional sharing of power between groups. This brief sets out some key findings from a research project investigating the relationship between census politics and the design of political institutions in Bosnia and Herzegovina, Kenya, Lebanon and Northern Ireland
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