Abundance analysis of Am binaries and search for tidally driven abundance anomalies - III. HD116657, HD138213, HD155375, HD159560, HD196544 and HD204188

We continue here the systematic abundance analysis of a sample of Am binaries in order to search for possible abundance anomalies driven by tidal interaction in these binary systems. New CCD observations in two spectral regions (6400-6500, 6660-6760 AA) of HD116657, HD138213, HD155375, HD159560, HD196544 and HD204188 were obtained. Synthetic spectrum analysis was carried out and basic stellar properties, effective temperatures, gravities, projected rotational velocities, masses, ages and abundances of several elements were determined. We conclude that all six stars are Am stars. These stars were put into the context of other Am binaries with 10 < Porb < 200 days and their abundance anomalies discussed in the context of possible tidal effects. There is clear anti-correlation of the Am peculiarities with v sin i. However, there seems to be also a correlation with the eccentricity and may be with the orbital period. The dependence on the temperature, age, mass, and microturbulence was studied as well. The projected rotational velocities obtained by us were compared to those of Royer et al. (2002) and Abt & Morrell (1995).Comment: 11 pages, 3 tables, 12 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

New Precision Orbits of Bright Double-Lined Spectroscopic Binaries. I: RR Lyncis, 12 Bootis, and HR 6169

Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coude' feed telescope at KPNO provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8IV), and HR 6169 (A2V). We derive orbital dimensions and minimum masses with accuracies of 0.06 to 0.9 %. The three systems, which have V magnitudes of 5.54, 4.83, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the prospect, when our spectroscopic observations are complemented by interferometric observations, of fully-determined orbits, precise masses, and distances. In the case of RR Lyn, which is also a detached eclipsing binary with a well-determined orbital inclination, we are able to determine the semimajor axis of the relative orbit, a = 29.32 +/- 0.04 Rsun, primary and secondary radii of 2.57 +/- 0.02 Rsun and 1.59 +/- 0.03 Rsun, respectively; and primary and secondary masses of 1.927 +/- 0.008 Msun and 1.507 +/- 0.004 Msun, respectively. Comparison of our new systemic velocity determination, gamma = -12.03 +/- 0.04 km/s, with an earlier one, gamma = -11.61 +/- 0.30 km/s, shows no evidence of any change in the systemic velocity in the 40 years separating the two measurements, a null result that neither confirms nor contradicts the presence of the low-mass third component proposed by Khaliullin & Khaliullina (2002). Our spectroscopic orbit of 12 Boo is more precise that that of Boden et al. (2005), but confirms their results about this system. Our analysis of HR 6169 has produced a major improvement in its orbital elements. The minimum masses of the primary and secondary are 2.20 +/- 0.01 and 1.64 +/- 0.02 Msun, respectively.Comment: To appear in the May A

Primary skin fibroblasts as a model of Parkinson's disease

Parkinson's disease is the second most frequent neurodegenerative disorder. While most cases occur sporadic mutations in a growing number of genes including Parkin (PARK2) and PINK1 (PARK6) have been associated with the disease. Different animal models and cell models like patient skin fibroblasts and recombinant cell lines can be used as model systems for Parkinson's disease. Skin fibroblasts present a system with defined mutations and the cumulative cellular damage of the patients. PINK1 and Parkin genes show relevant expression levels in human fibroblasts and since both genes participate in stress response pathways, we believe fibroblasts advantageous in order to assess, e.g. the effect of stressors. Furthermore, since a bioenergetic deficit underlies early stage Parkinson's disease, while atrophy underlies later stages, the use of primary cells seems preferable over the use of tumor cell lines. The new option to use fibroblast-derived induced pluripotent stem cells redifferentiated into dopaminergic neurons is an additional benefit. However, the use of fibroblast has also some drawbacks. We have investigated PARK6 fibroblasts and they mirror closely the respiratory alterations, the expression profiles, the mitochondrial dynamics pathology and the vulnerability to proteasomal stress that has been documented in other model systems. Fibroblasts from patients with PARK2, PARK6, idiopathic Parkinson's disease, Alzheimer's disease, and spinocerebellar ataxia type 2 demonstrated a distinct and unique mRNA expression pattern of key genes in neurodegeneration. Thus, primary skin fibroblasts are a useful Parkinson's disease model, able to serve as a complement to animal mutants, transformed cell lines and patient tissues

Auditory Spatial Acuity Approximates the Resolving Power of Space-Specific Neurons

The relationship between neuronal acuity and behavioral performance was assessed in the barn owl (Tyto alba), a nocturnal raptor renowned for its ability to localize sounds and for the topographic representation of auditory space found in the midbrain. We measured discrimination of sound-source separation using a newly developed procedure involving the habituation and recovery of the pupillary dilation response. The smallest discriminable change of source location was found to be about two times finer in azimuth than in elevation. Recordings from neurons in its midbrain space map revealed that their spatial tuning, like the spatial discrimination behavior, was also better in azimuth than in elevation by a factor of about two. Because the PDR behavioral assay is mediated by the same circuitry whether discrimination is assessed in azimuth or in elevation, this difference in vertical and horizontal acuity is likely to reflect a true difference in sensory resolution, without additional confounding effects of differences in motor performance in the two dimensions. Our results, therefore, are consistent with the hypothesis that the acuity of the midbrain space map determines auditory spatial discrimination

Degradation of 4-fluorophenol by Arthrobacter sp. strain IF1

A Gram-positive bacterial strain capable of aerobic biodegradation of 4-fluorophenol (4-FP) as the sole source of carbon and energy was isolated by selective enrichment from soil samples collected near an industrial site. The organism, designated strain IF1, was identified as a member of the genus Arthrobacter on the basis of 16S ribosomal RNA gene sequence analysis. Arthrobacter strain IF1 was able to mineralize 4-FP up to concentrations of 5 mM in batch culture. Stoichiometric release of fluoride ions was observed, suggesting that there is no formation of halogenated dead-end products during 4-FP metabolism. The degradative pathway of 4-FP was investigated using enzyme assays and identification of intermediates by gas chromatography (GC), GC–mass spectrometry (MS), high-performance liquid chromatography, and liquid chromatography–MS. Cell-free extracts of 4-FP-grown cells contained no activity for catechol 1,2-dioxygenase or catechol 2,3-dioxygenase, which indicates that the pathway does not proceed through a catechol intermediate. Cells grown on 4-FP oxidized 4-FP, hydroquinone, and hydroxyquinol but not 4-fluorocatechol. During 4-FP metabolism, hydroquinone accumulated as a product. Hydroquinone could be converted to hydroxyquinol, which was further transformed into maleylacetic acid and β-ketoadipic acid. These results indicate that the biodegradation of 4-FP starts with a 4-FP monooxygenase reaction that yields benzoquinone, which is reduced to hydroquinone and further metabolized via the β-ketoadipic acid pathway

Roles for the coactivators CBP and p300 and the APC/C E3 ubiquitin ligase in E1A-dependent cell transformation

Adenovirus early region 1A (E1A) possesses potent transforming activity when expressed in concert with activated ras or E1B genes in in vitro tissue culture systems such as embryonic human retinal neuroepithelial cells or embryonic rodent epithelial and fibroblast cells. Early region 1A has thus been used extensively and very effectively as a tool to determine the molecular mechanisms that underlie the basis of cellular transformation. In this regard, roles for the E1A-binding proteins pRb, p107, p130, cyclic AMP response element-binding protein (CBP)/p300, p400, TRRAP and CtBP in cellular transformation have been established. However, the mechanisms by which E1A promotes transformation through interaction with these partner proteins are not fully delineated. In this review, we focus on recent advances in our understanding of CBP/p300 function, particularly with regard to its relationship to the anaphase-promoting complex/cyclosome E3 ubiquitin ligase, which has recently been shown to interact and affect the activity of CBP/p300 through interaction domains that are evolutionarily conserved in E1A

JKA97, a Novel Benzylidene Analog of Harmine, Exerts Anti-Cancer Effects by Inducing G1 Arrest, Apoptosis, and p53-Independent Up-Regulation of p21

JKA97, a benzylidene analog of harmine, has been found to be a promising drug candidate for human cancer therapy, although the underlying molecular mechanisms have not been fully demonstrated. In this study, we evaluated the effects of JKA97 on human breast cancer cells in vitro and in vivo. JKA97 inhibited the growth and proliferation of MCF7 (p53 wild-type), MCF7 (p53 knockdown), and MDA-MB-468 (p53 mutant) cells in a dose-dependent manner. Treatment with JKA97 arrested breast cancer cells in G1 phase and induced apoptosis. JKA97 also significantly suppressed the growth of MCF7 and MDA-MB-468 xenograft tumors. It regulated the expression levels of G1 phase regulators, such as p21, p27, cyclinE, and cylinD1. JKA97 activated p21 transcription, independent of p53, but had little effect on p21 protein stability/degradation. In summary, our results suggest that JKA97 inhibits human breast cancer cell growth through activating p21, independent of p53, which provides a basis for developing this compound as a novel drug for human breast cancer therapy

Human papillomavirus prevalence in women attending routine cervical screening in South Wales, UK: a cross-sectional study

In this cross-sectional population-based study we determine human papillomavirus (HPV) prevalence in South Wales to provide comprehensive baseline data for future assessment of the impact of prophylactic HPV vaccination and to help inform future screening strategies. Liquid-based cytology samples from women attending routine cervical screening were collected (n=10 000: mean age 38 years, 93% cytology negative, and 64.8% from the 50% least deprived LSOA according to social deprivation score (SDS)). High-Risk (HR) and Low-Risk HPV screening was performed using HPV PCR-EIA with genotyping of HR positives and data correlated with age, SDS and cytology. Overall HPV prevalence was 13.5% (9.3% age standardised) and the most frequent HR types were HPV 16, 31, 18 and 58. In HR HPV-positive cases 42.4% had a single HR type and they were predominant in women with severe cytological abnormalities. Here, 66% of all HR HPV cases were in women aged 30 years of age or less and SDS had no significant effect on HPV status. HPV prevalence increased significantly with degree of dyskarosis from 7% in cytology negative samples to 80% in samples with severe cytological abnormalities (P-value <0.0001). Overall, 46% of HR HPV cases were positive for the two HR types targeted by the prophylactic vaccines (HPV 16 and HPV 18). The data presented represents the largest type-specific investigation of HPV prevalence in an unselected UK population

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO