525 research outputs found
Associations between Cognition, Gender and Monocyte Activation among HIV Infected Individuals in Nigeria.
The potential role of gender in the occurrence of HIV-related neurocognitive impairment (NCI) and associations with markers of HIV-related immune activity has not been previously examined. In this study 149 antiretroviral-naïve seropositive subjects in Nigeria (SP, 92 women and 57 men) and 58 seronegative (SN, 38 women and 20 men) were administered neuropsychological testing that assessed 7 ability domains. From the neuropsychological test scores was calculated a global deficit score (GDS), a measure of overall NCI. Percentages of circulating monocytes and plasma HIV RNA, soluble CD163 and soluble CD14 levels were also assessed. HIV SP women were found to be younger, more educated and had higher CD4+ T cell counts and borderline higher viral load measures than SP men. On the neuropsychological testing, SP women were more impaired in speed of information processing and verbal fluency and had a higher mean GDS than SN women. Compared to SP men, SP women were also more impaired in speed of information processing and verbal fluency as well as on tests of learning and memory. Numbers of circulating monocytes and plasma sCD14 and sCD163 levels were significantly higher for all SP versus all SN individuals and were also higher for SP women and for SP men versus their SN counterparts. Among SP women, soluble CD14 levels were slightly higher than for SP men, and SP women had higher viral load measurements and were more likely to have detectable virus than SP men. Higher sCD14 levels among SP women correlated with more severe global impairment, and higher viral load measurements correlated with higher monocyte numbers and sCD14 and sCD14 levels, associations that were not observed for SP men. These studies suggest that the risk of developing NCI differ for HIV infected women and men in Nigeria and, for women, may be linked to effects from higher plasma levels of HIV driving activation of circulating monocytes
Financial Transaction Tax: Small is Beautiful
The case for taxing financial transactions merely to raise more revenues from the financial sector is not particularly strong. Better alternatives to tax the financial sector are likely to be available. However, a tax on financial transactions could be justified in order to limit socially
undesirable transactions when more direct means of doing so are unavailable for political or
practical reasons. Some financial transactions are indeed likely to do more harm than good,
especially when they contribute to the systemic risk of the financial system. However, such a
financial transaction tax should be very small, much smaller than the negative externalities in
question, because it is a blunt instrument that also drives out socially useful transactions.
There is a case for taxing over-the-counter derivative transactions at a somewhat higher rate
than exchange-based derivative transactions. More targeted remedies to drive out socially
undesirable transactions should be sought in parallel, which would allow, after their
implementation, to reduce or even phase out financialtransaction taxes
MicroRNAs in Tumor Endothelial Cells: Regulation, Function and Therapeutic Applications
Tumor endothelial cells (TECs) are key stromal components of the tumor microenvironment,
and are essential for tumor angiogenesis, growth and metastasis. Accumulating evidence has
shown that small single-stranded non-coding microRNAs (miRNAs) act as powerful endogenous
regulators of TEC function and blood vessel formation. This systematic review provides an upto-date overview of these endothelial miRNAs. Their expression is mainly regulated by hypoxia,
pro-angiogenic factors, gap junctions and extracellular vesicles, as well as long non-coding RNAs
and circular RNAs. In preclinical studies, they have been shown to modulate diverse fundamental
angiogenesis-related signaling pathways and proteins, including the vascular endothelial growth
factor (VEGF)/VEGF receptor (VEGFR) pathway; the rat sarcoma virus (Ras)/rapidly accelerated
fibrosarcoma (Raf)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated
kinase (ERK) pathway; the phosphoinositide 3-kinase (PI3K)/AKT pathway; and the transforming
growth factor (TGF)-β/TGF-β receptor (TGFBR) pathway, as well as krüppel-like factors (KLFs),
suppressor of cytokine signaling (SOCS) and metalloproteinases (MMPs). Accordingly, endothelial
miRNAs represent promising targets for future anti-angiogenic cancer therapy. To achieve this, it will
be necessary to further unravel the regulatory and functional networks of endothelial miRNAs and
to develop safe and efficient TEC-specific miRNA delivery technologies
Nuclear RNA sequencing of the mouse erythroid cell transcriptome.
In addition to protein coding genes a substantial proportion of mammalian genomes are transcribed. However, most transcriptome studies investigate steady-state mRNA levels, ignoring a considerable fraction of the transcribed genome. In addition, steady-state mRNA levels are influenced by both transcriptional and posttranscriptional mechanisms, and thus do not provide a clear picture of transcriptional output. Here, using deep sequencing of nuclear RNAs (nucRNA-Seq) in parallel with chromatin immunoprecipitation sequencing (ChIP-Seq) of active RNA polymerase II, we compared the nuclear transcriptome of mouse anemic spleen erythroid cells with polymerase occupancy on a genome-wide scale. We demonstrate that unspliced transcripts quantified by nucRNA-seq correlate with primary transcript frequencies measured by RNA FISH, but differ from steady-state mRNA levels measured by poly(A)-enriched RNA-seq. Highly expressed protein coding genes showed good correlation between RNAPII occupancy and transcriptional output; however, genome-wide we observed a poor correlation between transcriptional output and RNAPII association. This poor correlation is due to intergenic regions associated with RNAPII which correspond with transcription factor bound regulatory regions and a group of stable, nuclear-retained long non-coding transcripts. In conclusion, sequencing the nuclear transcriptome provides an opportunity to investigate the transcriptional landscape in a given cell type through quantification of unspliced primary transcripts and the identification of nuclear-retained long non-coding RNAs
NWP-based lightning prediction using flexible count data regression
A method to predict lightning by postprocessing numerical weather prediction
(NWP) output is developed for the region of the European Eastern Alps.
Cloud-to-ground (CG) flashes – detected by the ground-based Austrian
Lightning Detection & Information System (ALDIS) network – are counted on
the 18×18 km2 grid of the 51-member NWP ensemble of the European
Centre for Medium-Range Weather Forecasts (ECMWF). These counts serve as the
target quantity in count data regression models for the occurrence of
lightning events and flash counts of CG. The probability of lightning
occurrence is modelled by a Bernoulli distribution. The flash counts are
modelled with a hurdle approach where the Bernoulli distribution is combined
with a zero-truncated negative binomial. In the statistical models the
parameters of the distributions are described by additive predictors, which
are assembled using potentially nonlinear functions of NWP covariates.
Measures of location and spread of 100 direct and derived NWP covariates
provide a pool of candidates for the nonlinear terms. A combination of
stability selection and gradient boosting identifies the nine (three) most
influential terms for the parameters of the Bernoulli (zero-truncated
negative binomial) distribution, most of which turn out to be associated with
either convective available potential energy (CAPE) or convective
precipitation. Markov chain Monte Carlo (MCMC) sampling estimates the final
model to provide credible inference of effects, scores, and
predictions. The selection of terms and MCMC sampling are applied for data of
the year 2016, and out-of-sample performance is evaluated for 2017. The
occurrence model outperforms a reference climatology – based on 7 years of
data – up to a forecast horizon of 5 days. The flash count model is
calibrated and also outperforms climatology for exceedance probabilities,
quantiles, and full predictive distributions.</p
Sleep analysis for elderly care using a low-resolution visual sensor network
Nearly half of the senior citizens report difficulty initiating and maintaining sleep. Frequent visits to the bathroom in the middle of the night is considered as one of the major reasons for sleep disorder. This leads to serious diseases such as depression and diabetes. In this paper, we propose to use a network of cheap low-resolution visual sensors (30 x 30 pixels) for long-term activity analysis of a senior citizen in a service flat. The main focus of our research is on elderly behaviour analysis to detect health deterioration. Specifically, this paper treats the analysis of sleep patterns. Firstly, motion patterns are detected. Then, a rule-based approach on the motion patterns is proposed to determine the wake up time and sleep time. The nightly bathroom visit is identified using a classification-based model. In our evaluation, we performed experiments on 10 months of real-life data. The ground truth is collected from the diaries in which the senior citizen wrote down his sleep time and wake up time. The results show accurate extraction of the sleep durations with an overall Mean Absolute Error (MAE) of 22.91 min and Spearman correlation coefficient of 0.69. Finally, the nightly bathroom visits analysis indicate sleep disorder in several nights
The electronic structure of (C59N)2 from high energy spectroscopy
We report the results of a detailed study of the occupied and unoccupied electronic structure of dimers of the new heterofullerene C59N by means of photoemission and electron energy-loss spectroscopy. A close similarity is found between the electronic structures of pristine (C59N)2 and C60 with an additional broadening of the spectra in the former due to the distortion of the fullerene cage caused both by dimerization and the chemical substitution. Both the occupied and unoccupied electronic states, as well as the interband transitions between them, attest to the high degree of molecular character retained in the solid state. Comparison of the shake-up structures in the C1s and N1s X-ray photo emission spectra confirm that the highest lying occupied states in the heterofullerene have a strong degree of N character, whereas the lowest lying unoccupied states have mainly C character. We also present the optical conductivity of the heterofullerene (derived from the loss function), which shows an optical gap of 1.4 eV, some 0.4 eV smaller than that of C60
On the structure of maximal solvable extensions and of Levi extensions of nilpotent algebras
We establish an improved upper estimate on dimension of any solvable algebra
s with its nilradical isomorphic to a given nilpotent Lie algebra n. Next we
consider Levi decomposable algebras with a given nilradical n and investigate
restrictions on possible Levi factors originating from the structure of
characteristic ideals of n. We present a new perspective on Turkowski's
classification of Levi decomposable algebras up to dimension 9.Comment: 21 pages; major revision - one section added, another erased;
author's version of the published pape
All solvable extensions of a class of nilpotent Lie algebras of dimension n and degree of nilpotency n-1
We construct all solvable Lie algebras with a specific n-dimensional
nilradical n_(n,2) (of degree of nilpotency (n-1) and with an (n-2)-dimensional
maximal Abelian ideal). We find that for given n such a solvable algebra is
unique up to isomorphisms. Using the method of moving frames we construct a
basis for the Casimir invariants of the nilradical n_(n,2). We also construct a
basis for the generalized Casimir invariants of its solvable extension s_(n+1)
consisting entirely of rational functions of the chosen invariants of the
nilradical.Comment: 19 pages; added references, changes mainly in introduction and
conclusions, typos corrected; submitted to J. Phys. A, version to be
publishe
Realizations of Real Low-Dimensional Lie Algebras
Using a new powerful technique based on the notion of megaideal, we construct
a complete set of inequivalent realizations of real Lie algebras of dimension
no greater than four in vector fields on a space of an arbitrary (finite)
number of variables. Our classification amends and essentially generalizes
earlier works on the subject.
Known results on classification of low-dimensional real Lie algebras, their
automorphisms, differentiations, ideals, subalgebras and realizations are
reviewed.Comment: LaTeX2e, 39 pages. Essentially exetended version. Misprints in
Appendix are correcte
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