On the determination of age and mass functions of stars in young open star clusters from the analysis of their luminosity functions

Based on the CCD observations of remote young open clusters NGC 2383, NGC 2384, NGC 4103, NGC 4755, NGC 7510 and Hogg 15, we constructed their observed luminosity functions (LFs). The observed LFs are corrected for field star contamination determined with the help of galactic star count model. In the case of Hogg 15 and NGC 2383 we also considered the additional contamination from neighbouring clusters NGC 4609 and NGC 2384 respectively. These corrections provided the realistic pattern of cluster LF in the vicinity of the MS turn on point and at fainter magnitudes, revealed the so called H-feature arising due to transition of the Pre-MS phase to MS, which is dependent on the cluster age. The theoretical LFs were constructed representing a cluster population model with continuous star formation for a short time scale and a power law Initial Mass Function (IMF) and these were fitted to the observed LF. As a result we are able to determine for each cluster a set of parameters, describing cluster population (the age, duration of star formation, IMF slope and percentage of field star contamination). It was found that in spite of the non-monotonic behaviour of observed LFs, cluster IMFs can be described as the power law functions with slopes similar to Salpeter's value. The present MS turn on cluster ages are several times lower than those derived from the fitting of theoretical isochrones to the turn off region of the upper Main Sequences.Comment: 17 pages, 5 figures, To appear in MNRA

To the letter vs the spirit: A case analysis of contrasting environmental management responses

Purpose: This paper examines why firms governed by the same environmental management standards within an industry exhibit contrasting responses, with some adhering to the letter and others achieving the spirit behind the standards. Design: Using Arena et al. (2010) as an analytical schema to examine the institutional dynamics behind such contrasting responses, the paper analyses archival and interview data relating to firm strategy, control technology and human expertise in two contrasting Australian forestry firms. Findings: The embedding and decoupling of environmental standards with a firm’s environmental management practices is influenced, first, by the extent to which founder directors and senior management integrate environmental responsibility with the underlying business motives and, second, by the use of organisational beliefs and values systems to institutionalise the integrated strategic rationality throughout the firm. Finally, informed by the institutionalised strategic rationality, the participation and expertise of actors across the organisational hierarchy determines the level to which the design and execution of the eco-control technologies move beyond merely monitoring compliance, and act to facilitate continuous improvement, knowledge integration and organisational learning at the operational level. Originality: This paper responds to institutional theorists’ call for a holistic explanation that considers the interactions among several intra-organisational factors to explain the dynamics behind why some firms decouple while others do not, even though the firms exist in the same social and regulatory context.Campbell Heggen, VG Sridharan and Nava Subramania

Hereditary pattern of cancer

Three thousand nine hundred and twelve patients with cancer in various sites reporting to the out patient department were questioned for history of cancer among blood relatives. A positive history of cancer was obtained in 154 of whom 89 were male and 65 female. Thirty nine patients gave history of cancer among siblings and five gave history of cancer among spouses related by consanguneous marriage. The other 110 gave history of cancer among second and third generation relatives. Sixty one percent maternal relatives of the female patients had cancer as compared to only 33 percent of paternal relatives. This difference was not seen among male patients where there were about 45 percent of maternal and 47 paternal relatives giving history of cancer. Further it was found that 6 of 20 patients with cancer of the breast, 7 of 22 with stomach cancer and 4 of 12 with cervix cancer had blood relatives with the same type of cancer

Membrane Binding of Parkinson's Protein alpha-Synuclein: Effect of Phosphorylation at Positions 87 and 129 by the S to D Mutation Approach

Biological and Soft Matter Physic

Young Clusters in the Magellanic Clouds II

We present the results of a quantitative study of the degree of extension to the boundary of the classical convective core within intermediate mass stars. The basis of our empirical study is the stellar population of four young populous clusters in the Magellanic Clouds which has been detailed in Keller, Bessell & Da Costa (2000). The sample affords a meaningful comparison with theoretical scenarios with varying degrees of convective core overshoot and binary star fraction. Two critical properties of the population, the main-sequence luminosity function and the number of evolved stars, form the basis of our comparison between the observed data set and that simulated from the stellar evolutionary models. On the basis of this comparison we conclude that the case of no convective core overshoot is excluded at a 2 sigma level.Comment: 27 pages, 12 figures, AJ accepte

In-orbit Performance of UVIT on ASTROSAT

We present the in-orbit performance and the first results from the ultra-violet Imaging telescope (UVIT) on ASTROSAT. UVIT consists of two identical 38cm coaligned telescopes, one for the FUV channel (130-180nm) and the other for the NUV (200-300nm) and VIS (320-550nm) channels, with a field of view of 28 $arcmin$. The FUV and the NUV detectors are operated in the high gain photon counting mode whereas the VIS detector is operated in the low gain integration mode. The FUV and NUV channels have filters and gratings, whereas the VIS channel has filters. The ASTROSAT was launched on 28th September 2015. The performance verification of UVIT was carried out after the opening of the UVIT doors on 30th November 2015, till the end of March 2016 within the allotted time of 50 days for calibration. All the on-board systems were found to be working satisfactorily. During the PV phase, the UVIT observed several calibration sources to characterise the instrument and a few objects to demonstrate the capability of the UVIT. The resolution of the UVIT was found to be about 1.4 - 1.7 $arcsec$ in the FUV and NUV. The sensitivity in various filters were calibrated using standard stars (white dwarfs), to estimate the zero-point magnitudes as well as the flux conversion factor. The gratings were also calibrated to estimate their resolution as well as effective area. The sensitivity of the filters were found to be reduced up to 15\% with respect to the ground calibrations. The sensitivity variation is monitored on a monthly basis. UVIT is all set to roll out science results with its imaging capability with good resolution and large field of view, capability to sample the UV spectral region using different filters and capability to perform variability studies in the UV.Comment: 10 pages, To appear in SPIE conference proceedings, SPIE conference paper, 201

Correction: Contribution of the Cpx envelope stress system to metabolism and virulence regulation in Salmonella enterica serovar Typhimurium

[This corrects the article DOI: 10.1371/journal.pone.0211584.]