425 research outputs found
Spinor-Vector Duality in Heterotic String Orbifolds
The three generation heterotic-string models in the free fermionic
formulation are among the most realistic string vacua constructed to date,
which motivated their detailed investigation. The classification of free
fermion heterotic string vacua has revealed a duality under the exchange of
spinor and vector representations of the SO(10) GUT symmetry over the space of
models. We demonstrate the existence of the spinor-vector duality using
orbifold techniques, and elaborate on the relation of these vacua to free
fermionic models.Comment: 20 pages. v2 minor corrections. Version to appear on JHEP. v3
misprints correcte
Titanium, Sinusitis, and the Yellow Nail Syndrome
Yellow nail syndrome is characterized by nail changes, respiratory disorders, and lymphedema. In a yellow nail patient with a skeletal titanium implant and with gold in her teeth, we found high levels of titanium in nail clippings. This study aims to examine the possible role of titanium in the genesis of the yellow nail syndrome. Nail clippings from patients with one or more features of the yellow nail syndrome were analyzed by energy dispersive X-ray fluorescence. Titanium was regularly found in finger nails in patients but not in control subjects. Visible nail changes were present in only half of the patients. Sinusitis with postnasal drip and cough was the most common complaint. The dominant source of titanium ions was titanium implants in the teeth or elsewhere. The titanium ions were released through the galvanic action of dental gold or amalgam or through the oxidative action of fluorides. In other patients the titanium was derived from titanium dioxide in drugs and confectionary. Stopping galvanic release of titanium ions or canceling exposure to titanium dioxide led to recovery. In one patient with a titanium implant, the symptoms recurred after renewed exposure to titanium. Yellow nail syndrome is caused by titaniu
Alcohol Intake and Alcohol-SNP Interactions Associated with Prostate Cancer Aggressiveness
Excessive alcohol intake is a well-known modifiable risk factor for many cancers. It is still unclear whether genetic variants or single nucleotide polymorphisms (SNPs) can modify alcohol intake's impact on prostate cancer (PCa) aggressiveness. The objective is to test the alcohol-SNP interactions of the 7501 SNPs in the four pathways (angiogenesis, mitochondria, miRNA, and androgen metabolism-related pathways) associated with PCa aggressiveness. We evaluated the impacts of three excessive alcohol intake behaviors in 3306 PCa patients with European ancestry from the PCa Consortium. We tested the alcohol-SNP interactions using logistic models with the discovery-validation study design. All three excessive alcohol intake behaviors were not significantly associated with PCa aggressiveness. However, the interactions of excessive alcohol intake and three SNPs (rs13107662 [CAMK2D, p = 6.2 × 10-6], rs9907521 [PRKCA,p = 7.1 × 10-5], and rs11925452 [ROBO1,p = 8.2 × 10-4]) were significantly associated with PCa aggressiveness. These alcohol-SNP interactions revealed contrasting effects of excessive alcohol intake on PCa aggressiveness according to the genotypes in the identified SNPs. We identified PCa patients with the rs13107662 (CAMK2D) AA genotype, the rs11925452 (ROBO1) AA genotype, and the rs9907521 (PRKCA) AG genotype were more vulnerable to excessive alcohol intake for developing aggressive PCa. Our findings support that the impact of excessive alcohol intake on PCa aggressiveness was varied by the selected genetic profiles
Non-Perturbative Superpotentials in F-theory and String Duality
We use open-closed string duality between F-theory on K3xK3 and type II
strings on CY manifolds without branes to study non-perturbative
superpotentials in generalized flux compactifications. On the F-theory side we
obtain the full flux potential including D3-instanton contributions and show
that it leads to an explicit and simple realization of the three ingredients of
the KKLT model for stringy dS vacua. The D3-instanton contribution is highly
non-trivial, can be systematically computed including the determinant factors
and demonstrates that a particular flux lifts very effectively zero modes on
the instanton. On the closed string side, we propose a generalization of the
Gukov-Vafa-Witten superpotential for type II strings on generalized CY
manifolds, depending on all moduli multiplets.Comment: 49 pages, harvmac, 1 figure; references & figures adde
Learning to live with Parkinson’s disease in the family unit:an interpretative phenomenological analysis of well-being
We investigated family members’ lived experience of Parkinson’s disease (PD) aiming to investigate opportunities for well-being. A lifeworld-led approach to healthcare was adopted. Interpretative phenomenological analysis was used to explore in-depth interviews with people living with PD and their partners. The analysis generated four themes: It’s more than just an illness revealed the existential challenge of diagnosis; Like a bird with a broken wing emphasizing the need to adapt to increasing immobility through embodied agency; Being together with PD exploring the kinship within couples and belonging experienced through support groups; and Carpe diem! illuminated the significance of time and fractured future orientation created by diagnosis. Findings were interpreted using an existential-phenomenological theory of well-being. We highlighted how partners shared the impact of PD in their own ontological challenges. Further research with different types of families and in different situations is required to identify services required to facilitate the process of learning to live with PD. Care and support for the family unit needs to provide emotional support to manage threats to identity and agency alongside problem-solving for bodily changes. Adopting a lifeworld-led healthcare approach would increase opportunities for well-being within the PD illness journey
Vitamin D receptor ChIP-seq in primary CD4+ cells: relationship to serum 25-hydroxyvitamin D levels and autoimmune disease
PMCID: PMC3710212This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Multi-Locus Sequence Analysis Reveals Profound Genetic Diversity among Isolates of the Human Pathogen Bartonella bacilliformis
Bartonella bacilliformis is the aetiological agent of human bartonellosis, a potentially life threatening infection of significant public health concern in the Andean region of South America. Human bartonellosis has long been recognised in the region but a recent upsurge in the number of cases of the disease and an apparent expansion of its geographical distribution have re-emphasized its contemporary medical importance. Here, we describe the development of a multi-locus sequence typing (MLST) scheme for B. bacilliformis and its application to an archive of 43 isolates collected from patients across Peru. MLST identified eight sequence types among these isolates and the delineation of these was generally congruent with those of the previously described typing scheme. Phylogenetic analysis based on concatenated sequence data derived from MLST loci revealed that seven of the eight sequence types were closely related to one another; however, one sequence type, ST8, exhibited profound evolutionary divergence from the others. The extent of this divergence was akin to that observed between other members of the Bartonella genus, suggesting that ST8 strains may be better considered as members of a novel Bartonella genospecies
Systematically missing confounders in individual participant data meta-analysis of observational cohort studies.
One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154,012 participants in 31 cohort
MultiMSOAR 2.0: An Accurate Tool to Identify Ortholog Groups among Multiple Genomes
The identification of orthologous genes shared by multiple genomes plays an important role in evolutionary studies and gene functional analyses. Based on a recently developed accurate tool, called MSOAR 2.0, for ortholog assignment between a pair of closely related genomes based on genome rearrangement, we present a new system MultiMSOAR 2.0, to identify ortholog groups among multiple genomes in this paper. In the system, we construct gene families for all the genomes using sequence similarity search and clustering, run MSOAR 2.0 for all pairs of genomes to obtain the pairwise orthology relationship, and partition each gene family into a set of disjoint sets of orthologous genes (called super ortholog groups or SOGs) such that each SOG contains at most one gene from each genome. For each such SOG, we label the leaves of the species tree using 1 or 0 to indicate if the SOG contains a gene from the corresponding species or not. The resulting tree is called a tree of ortholog groups (or TOGs). We then label the internal nodes of each TOG based on the parsimony principle and some biological constraints. Ortholog groups are finally identified from each fully labeled TOG. In comparison with a popular tool MultiParanoid on simulated data, MultiMSOAR 2.0 shows significantly higher prediction accuracy. It also outperforms MultiParanoid, the Roundup multi-ortholog repository and the Ensembl ortholog database in real data experiments using gene symbols as a validation tool. In addition to ortholog group identification, MultiMSOAR 2.0 also provides information about gene births, duplications and losses in evolution, which may be of independent biological interest. Our experiments on simulated data demonstrate that MultiMSOAR 2.0 is able to infer these evolutionary events much more accurately than a well-known software tool Notung. The software MultiMSOAR 2.0 is available to the public for free
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