Isomorphisms of algebras of Colombeau generalized functions

We show that for smooth manifolds X and Y, any isomorphism between the special algebra of Colombeau generalized functions on X, resp. Y is given by composition with a unique Colombeau generalized function from Y to X. We also identify the multiplicative linear functionals from the special algebra of Colombeau generalized functions on X to the ring of Colombeau generalized numbers. Up to multiplication with an idempotent generalized number, they are given by an evaluation map at a compactly supported generalized point on X.Comment: 10 page

Multiwavelength Observations of the Runaway Binary HD 15137

HD 15137 is an intriguing runaway O-type binary system that offers a rare opportunity to explore the mechanism by which it was ejected from the open cluster of its birth. Here we present recent blue optical spectra of HD 15137 and derive a new orbital solution for the spectroscopic binary and physical parameters of the O star primary. We also present the first XMM-Newton observations of the system. Fits of the EPIC spectra indicate soft, thermal X-ray emission consistent with an isolated O star. Upper limits on the undetected hard X-ray emission place limits on the emission from a proposed compact companion in the system, and we rule out a quiescent neutron star in the propellor regime or a weakly accreting neutron star. An unevolved secondary companion is also not detected in our optical spectra of the binary, and it is difficult to conclude that a gravitational interaction could have ejected this runaway binary with a low mass optical star. HD 15137 may contain an elusive neutron star in the ejector regime or a quiescent black hole with conditions unfavorable for accretion at the time of our observations.Comment: Accepted to A

Expression of telomeric repeat binding factor-1 in astroglial brain tumors

OBJECTIVE: In human somatic cells, telomeres shorten with successive cell divisions, resulting in progressive genomic instability, altered gene expression, and cell death. Recently, telomere-specific deoxyribonucleic acid-binding proteins, such as telomeric repeat binding factor-1 (TRF1), have been proposed as candidates for the role of molecules regulating telomerase activity, and they have been suggested to play key roles in the maintenance of telomere function. The present study was designed to assess TRF1 expression in human astroglial brain tumors and to speculate on the clinical implications of its expression. METHODS: Twenty flash-frozen surgical specimens obtained from adult patients who underwent craniotomy for microsurgical tumor resection, histologically verified as World Health Organization Grade II to IV astrocytomas, were used. Expression of TRF1 in astrocytomas of different grades was studied by means of both immunohistochemical and Western blotting analysis. The correlation between the extent of TRF1 expression and histological grading, performance status, and length of survival of patients underwent statistical analyses. RESULTS: TRF1 was expressed in all tumor samples. The level of its expression was variable, decreasing from low-grade through high-grade astrocytomas (P 0.0032). TRF1 expression correlated with the patient’s length of survival (P 0.001) and performance status (P 0.001) and proved to be an independent indicator of length of survival. CONCLUSION: Our findings suggest that the loss of TRF1 expression capability, as a result of down-regulation of TRF1 expression in malignant gliomas cells, may play a role in the malignant progression of astroglial brain tumors

HD 259440: The Proposed Optical Counterpart of the gamma-ray Binary HESS J0632+057

HD 259440 is a B0pe star that was proposed as the optical counterpart to the gamma-ray source HESS J0632+057. Here we present optical spectra of HD 259440 acquired to investigate the stellar parameters, the properties of the Be star disk, and evidence of binarity in this system. Emission from the H-alpha line shows evidence of a spiral density wave in the nearly edge-on disk. We find a best fit stellar effective temperature of 27500-30000 K and a log surface gravity of 3.75-4.0, although our fits are somewhat ambiguous due to scattered light from the circumstellar disk. We derive a mass of 13.2-19.0 M_sun and a radius of 6.0-9.6 R_sun. By fitting the spectral energy distribution, we find a distance between 1.1-1.7 kpc. We do not detect any significant radial velocity shifts in our data, ruling out orbital periods shorter than one month. If HD 259440 is a binary, it is likely a long period (> 100 d) system.Comment: ApJ, in pres

Deep Chandra observations of TeV binaries I: LSI +61 303

We report on a 95ks Chandra observation of the TeV emitting High Mass X-ray Binary LSI +61 303, using the ACIS-S camera in Continuos Clocking mode to search for a possible X-ray pulsar in this system. The observation was performed while the compact object was passing from phase 0.94 to 0.98 in its orbit around the Be companion star (hence close to the apastron passage). We did not find any periodic or quasi-periodic signal (at this orbital phase) in a frequency range of 0.005-175 Hz. We derived an average pulsed fraction 3 sigma upper limit for the presence of a periodic signal of ~10% (although this limit is strongly dependent on the frequency and the energy band), the deepest limit ever reached for this object. Furthermore, the source appears highly variable in flux and spectrum even in this very small orbital phase range, in particular we detect two flares, lasting thousands of seconds, with a very hard X-ray spectrum with respect to the average source spectral distribution. The X-ray pulsed fraction limits we derived are lower than the pulsed fraction of any isolated rotational-powered pulsar, in particular having a TeV counterpart. In this scenario most of the X-ray emission of LSI +61 303 should necessarily come from the interwind or inner-pulsar wind zone shock rather than from the magnetosphere of the putative pulsar. Furthermore, we did not find evidence for the previously suggested extended X-ray emission (abridged).Comment: 9 pages, 6 figures, MNRAS in pres

Deep Chandra observations of TeV binaries II: LS 5039

We report on Chandra observations of the TeV emitting High Mass X-ray Binary LS 5039, for a total exposure of ~70ks, using the ACIS-S camera in Continuos Clocking mode to search for a possible X-ray pulsar in this system. We did not find any periodic or quasi-periodic signal in the 0.3-0.4 and 0.75-0.9 orbital phases, and in a frequency range of 0.005-175 Hz. We derived an average pulsed fraction 3sigma upper limit for the presence of a periodic signal of ~15% (depending on the frequency and the energy band), the deepest limit ever reached for this object. If the X-ray emission of LS 5039 is due (at least in part) to a rotational powered pulsar, the latter is either spinning faster than ~5.6 ms, or having a beam pointing away from our line of sight, or contributing to ~15% of the total X-ray emission of the system in the orbital phases we observed.Comment: 9 pages, 5 figures, MNRAS in pres

Fermi LAT Observations of LS I +61 303: First detection of an orbital modulation in GeV Gamma Rays

This Letter presents the first results from the observations of LSI +61 303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 +/- 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 +/- 0.03(stat) +/- 0.07(syst) 10^{-6} ph cm^{-2} s^{-1}, with a cutoff at 6.3 +/- 1.1(stat) +/- 0.4(syst) GeV and photon index Gamma = 2.21 +/- 0.04(stat) +/- 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest the link between HE and VHE gamma rays is nontrivial.Comment: 7 pages, 5 figures, accepted for publication in ApJ Letters 21 July 200

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Phase II Randomized, Double-Masked, Vehicle-Controlled Trial of Recombinant Human Nerve Growth Factor for Neurotrophic Keratitis

Purpose: To evaluate the safety and efficacy of topical recombinant human nerve growth factor (rhNGF) for treating moderate-to-severe neurotrophic keratitis (NK), a rare degenerative corneal disease resulting from impaired corneal innervation. Design: Phase II multicenter, randomized, double-masked, vehicle-controlled trial. Participants: Patients with stage 2 (moderate) or stage 3 (severe) NK in 1 eye. Methods: The REPARO phase II study assessed safety and efficacy in 156 patients randomized 1:1:1 to rhNGF 10 \u3bcg/ml, 20 \u3bcg/ml, or vehicle. Treatment was administered 6 drops per day for 8 weeks. Patients then entered a 48- or 56-week follow-up period. Safety was assessed in all patients who received study treatment, whereas efficacy was by intention to treat. Main Outcome Measures: Corneal healing (defined as <0.5-mm maximum diameter of fluorescein staining in the lesion area) was assessed by masked central readers at week 4 (primary efficacy end point) and week 8 (key secondary end point) of controlled treatment. Corneal healing was reassessed post hoc by masked central readers using a more conservative measure (0-mm staining in the lesion area and no other persistent staining). Results: At week 4 (primary end point), 19.6% of vehicle-treated patients achieved corneal healing (<0.5-mm lesion staining) versus 54.9% receiving rhNGF 10 \u3bcg/ml (+35.3%; 97.06% confidence interval [CI], 15.88\u201354.71; P < 0.001) and 58.0% receiving rhNGF 20 \u3bcg/ml (+38.4%; 97.06% CI, 18.96\u201357.83; P < 0.001). At week 8 (key secondary end point), 43.1% of vehicle-treated patients achieved less than 0.5-mm lesion staining versus 74.5% receiving rhNGF 10 \u3bcg/ml (+31.4%; 97.06% CI, 11.25\u201351.49; P = 0.001) and 74.0% receiving rhNGF 20 \u3bcg/ml (+30.9%; 97.06% CI, 10.60\u201351.13; P = 0.002). Post hoc analysis of corneal healing by the more conservative measure (0-mm lesion staining and no other persistent staining) maintained statistically significant differences between rhNGF and vehicle at weeks 4 and 8. More than 96% of patients who healed after controlled rhNGF treatment remained recurrence free during follow-up. Treatment with rhNGF was well tolerated; adverse effects were mostly local, mild, and transient. Conclusions: Topical rhNGF is safe and more effective than vehicle in promoting healing of moderate-to-severe NK