Radial departures and plane embeddings of arc-like continua

We study the problem of Nadler and Quinn from 1972, which asks whether, given an arc-like continuum $X$ and a point $x \in X$, there exists an embedding of $X$ in $\mathbb{R}^2$ for which $x$ is an accessible point. We develop the notion of a radial departure of a map $f \colon [-1,1] \to [-1,1]$, and establish a simple criterion in terms of the bonding maps in an inverse system on intervals to show that there is an embedding of the inverse limit for which a given point is accessible. Using this criterion, we give a partial affirmative answer to the problem of Nadler and Quinn, under some technical assumptions on the bonding maps of the inverse system.Comment: 23 pages, 8 figure

Mouse Natural Killer (NK) Cells Express the Nerve Growth Factor Receptor TrkA, which Is Dynamically Regulated

Background: Nerve growth factor (NGF) is a neurotrophin crucial for the development and survival of neurons. It also acts on cells of the immune system which express the NGF receptors TrkA and p75 NTR and can be produced by them. However, mouse NK cells have not yet been studied in this context. Methodology/Principal Findings: We used cell culture, flow cytometry, confocal microscopy and ELISA assays to investigate the expression of NGF receptors by NK cells and their secretion of NGF. We show that resting NK cells express TrkA and that the expression is different on NK cell subpopulations defined by the relative presence of CD27 and CD11b. Expression of TrkA is dramatically increased in IL-2-activated NK cells. The p75 NTR is expressed only on a very low percentage of NK cells. Functionally, NGF moderately inhibits NK cell degranulation, but does not influence proliferation or cytokine production. NK cells do not produce NGF. Conclusions/Significance: We demonstrate for the first time that mouse NK cells express the NGF receptor TrkA and tha

CHARACTERIZATION OF DEFECT CENTRES IN SEMICONDUCTORS BY ADVANCED ENDOR TECHNIQUES

The advanced magnetic resonance techniques and their application to the studies of defects in semiconductors will be reviewed. Transient and stationary ENDOR, opticalły detected ENDOR and doubłe ENDOR variations will be briefly discussed while special attention will be given to the Field-Stepped-ENDOR technique. The successful application of the advanced ENDOR techniques for the structure determination of complex defects will be illustrated by the examples concerning the boron-vacancy complex and thermal donors in silicon and the gallium vacancy in gallium phosphide

Long-term survival and transmission of INI1-mutation via nonpenetrant males in a family with rhabdoid tumour predisposition syndrome

Rhabdoid tumour predisposition syndrome (RTPS) is a rare syndrome caused by inheritance of a mutated INI1 gene for which only two multigeneration families have been reported. To further characterise the genotype and phenotype of RTPS, we present a third family in which at least three cousins developed an atypical teratoid/rhabdoid tumour (AT/RT) at a young age. Two of these patients showed unusual long survival, and one of these developed an intracranial meningioma and a myoepithelioma of the lip in adulthood. Mutation analysis of INI1 revealed a germline G>A mutation in the donor splice site of exon 4 (c.500+1G>A) in the patients and in their unaffected fathers. This mutation prevents normal splicing and concomitantly generates a stop codon, resulting in nonsense-mediated mRNA decay. Biallelic inactivation of INI1 in the tumours, except for the meningioma, was confirmed by absence of nuclear INI1-protein staining. The myoepithelioma of one of the patients carried an identical somatic rearrangement in the NF2 gene as the AT/RT, indicating that both tumours originated from a common precursor cell. In conclusion, this study demonstrates for the first time transmission of a germline INI1-mutation in a RTPS family via nonpenetrant males, long-term survival of two members of this family with an AT/RT, and involvement of INI1 in the pathogenesis of myoepithelioma

First-principle study of excitonic self-trapping in diamond

We present a first-principles study of excitonic self-trapping in diamond. Our calculation provides evidence for self-trapping of the 1s core exciton and gives a coherent interpretation of recent experimental X-ray absorption and emission data. Self-trapping does not occur in the case of a single valence exciton. We predict, however, that self-trapping should occur in the case of a valence biexciton. This process is accompanied by a large local relaxation of the lattice which could be observed experimentally.Comment: 12 pages, RevTex file, 3 Postscript figure

Secondary meningioma in a long-term survivor of atypical teratoid/rhabdoid tumour with a germline INI1 mutation

OBJECTIVE: We report on a patient who developed a meningioma more than two decades after removal at a young age of an atypical teratoid/rhabdoid tumour (AT/RT), which was due to a germline INI1 mutation, and radio- and chemotherapy. MATERIALS AND METHODS: We present genetic evidence that the meningioma is not a recurrence or metastasis of the AT/RT and not due to the INI1 mutation, but is a radiation-induced tumour. CONCLUSION: This is the first case illustrating that improved survival of young patients with an AT/RT after aggressive treatment may be gained at the cost of an increased risk for the development of radiation-induced, non-INI1-related tumours