Corporate governance and the long-run performance of firms issuing seasoned equity: An Australian study

Corporate governance has been propelled to the forefront of contemporary business thinking by a string of high profile corporate collapses and dramatic regulatory responses in the United States, Australia and in other countries as well. A particularly extensive body of research has emerged surrounding the relationship between corporate governance and firm performance. We combine the governance literature with evidence on the long-term underperformance of firms issuing seasoned equity to examine the benefits of corporate governance in a setting where it is more likely to matter. That is, we address the question, Does good corporate governance mitigate post-issue underperformance? For a broad sample of Australian seasoned equity offerings and employing a comprehensive, self-constructed governance database, we first demonstrate that issuing firms substantially underperform a variety of benchmarks over the long term, confirming similar findings in the existing literature. We then find evidence that better-governed firms do not experience the same degree of post-issue underperformance. Our findings, which are robust to a variety of estimation methods and econometric specifications, are consistent with the windows of opportunity hypothesis and with equity raisings being an important channel through which better corporate governance can improve future performance

Ultra low-mass star and substellar formation in sigma Orionis

The nearby young sigma Orionis cluster (~360 pc, ~3 Ma) is becoming one of the most important regions for the study of ultra low-mass star formation and its extension down to the mass regimes of the brown dwarfs and planetary-mass objects. Here, I introduce the sigma Orionis cluster and present three studies that the JOVIAN group is developing: a pilot programme of near-infrared adaptive-optics imaging, intermediate-resolution optical spectroscopy of a large sample of stars of the cluster and a study of the mass function down to the planetary-mass domain. This paper is a summary of the content of four posters that I presented in the Ultra low-mass star formation and evolution Workshop, as single author or on behalf of different collaborations.Comment: 4 pages, 4 figures. Proceeding at the IAC-TNG Workshop on Ultra low-mass star formation and evolution, 28 June - 1 July 2005, La Palma, Canary Islands, Spain. Accepted for publication in Astron. Nach

Interrogating spaces of and for the dead as ‘alternative space’: cemeteries, corpses and sites of Dark Tourism.

This paper considers spaces associated with death and the dead body as social spaces with an ambiguous character. The experience of Western societies has tended to follow a path of an increased sequestration of death and the dead body over the last two centuries. Linked to this, the study of spaces associated with death, dying and bodily disposal and the dead body itself have been marginalised in most academic disciplines over this period. Such studies have therefore been simultaneously ‘alternative’ within an academic paradigm which largely failed to engage with death and involved a focus on types of spaces which have been considered marginal, liminal or ‘alternative’, such as graveyards, mortuaries, heritage tourism sites commemorating death and disaster, and the dead body itself. However, this paper traces more recent developments in society and academia which would begin to question this labelling of such studies and spaces as alternative, or at least blur the boundaries between mainstream and alternative in this context. Through considering the increased presence of death and the dead body in a range of socio-cultural, economic and political contexts we argue that both studies of, and some spaces of, death, dying and disposal are becoming less ‘alternative’ but remain highly ambiguous nonetheless. This argument is addressed through a specific focus on three key interlinked spaces: cemeteries, corpses and sites of dark tourism

The CIDA Variability Survey of Orion OB1. I: the low-mass population of Ori OB 1a and 1b

We present results of a large scale, multi-epoch optical survey of the Ori OB1 association, carried out with the QuEST camera at the Venezuela National Astronomical Observatory. We identify for the first time the widely spread low-mass, young population in the Orion OB1a and OB1b sub-associations. Candidate members were picked up by their variability in the V-band and position in color-magnitude diagrams. We obtained spectra to confirm membership. In a region spanning ~ 68 deg^2 we found 197 new young stars; of these, 56 are located in the Ori OB1a subassociation and 142 in Ori OB1b. Comparison with the spatial extent of molecular gas and extinction maps indicates that the subassociation Ori 1b is concentrated within a ring-like structure of radius ~2 deg (~15 pc at 440 pc), centered roughly on the star epsilon Ori in the Orion belt. The ring is apparent in 13CO and corresponds to a region with an extinction Av>=1. The stars exhibiting strong Ha emission, an indicator of active accretion, are found along this ring, while the center is populated with weak Ha emitting stars. In contrast, Ori OB1a is located in a region devoid of gas and dust. We identify a grouping of stars within a ~3 deg^2 area located in 1a, roughly clustered around the B2 star 25 Ori. The Herbig Ae/Be star V346 Ori is also associated with this grouping, which could be an older analog of sigma Ori. Using using several sets of evolutionary tracks we find an age of 7 - 10 Myr for Ori 1a and of ~4 - 6 Myr for Ori OB1b, consistent with previous estimates from OB stars. Indicators such as the equivalent width of Ha and near-IR excesses show that while a substantial fraction of accreting disks remain at ages ~5 Myr, inner disks are essentially dissipated by 10 Myr.Comment: 44 pages, 12 figures, to appear in the Astronomical Journal. (Abridged abstract - to fit length limit in astroph) Full resolution figures in http://www.cida.ve/~briceno/publications

Stars and brown dwarfs in the sigma Orionis cluster: the Mayrit catalogue

The young sigma Orionis cluster is an indispensable basis for understanding the formation and evolution of stars, brown dwarfs and planetary-mass objects. Our knowledge of its stellar population is, however, incomplete. I present the Mayrit catalogue, that comprises most of the stars and high-mass brown dwarfs of the cluster. The basis of this work is an optical-near infrared correlation between the 2MASS and DENIS catalogues in a circular area of radius 30 arcmin centred on the OB-type binary sigma Ori AB. The analysis is supported on a bibliographic search of confirmed cluster members with features of youth and on additional X-ray, mid-infrared and astrometric data. I list 241 sigma Orionis stars and brown dwarfs with known features of youth, 97 candidate cluster members (40 are new) and 115 back- and foreground sources in the survey area. The 338 cluster members and member candidates constitute the Mayrit catalogue. This catalogue is a suitable input for studying the spatial ditribution, multiplicity, properties and frequency of discs and the complete mass function of sigma Orionis.Comment: accepted for publication in A&A, section 14. Online catalogs and dat

Triggered Star Formation on the Border of the Orion-Eridanus Superbubble

A census of classical T Tauri stars and Herbig Ae/Be stars has been performed around the Orion-Eridanus Superbubble which is ionized and created by the Ori OB1 association. This sample is used to study the spatial distribution of newborn stars, hence the recent star formation sequence, in the region that includes two giant molecular clouds (Orion A and B) and additional smaller clouds (NGC 2149, GN 05.51.4, VdB 64, the Crossbones, the Northern Filament, LDN 1551, LDN 1558, and LDN 1563). Most of the molecular clouds are located on the border of the Superbubble, and associated with H-alpha filaments and star formation activity, except the Northern Filament which is probably located outside the Superbubble. This suggests that while star formation progresses from the oldest Ori OB1a subgroup to 1b, 1c and 1d, the Superbubble compresses and initiates starbirth in clouds such as NGC 2149, GN 05.51.4, VdB 64, and the Crossbones, which are located more than one hundred pc away from the center of the Superbubble, and even in clouds some two hundred pc away, i.e., in LDN 1551, LDN 1558, and LDN 1563. A superbubble appears to have potentially a long-range influence in triggering next-generation star formation in an OB association.Comment: Accepted for publication in Ap

Retrospective survey for sialidase activity in Mycoplasma pneumoniae isolates from cases of community-acquired pneumonia

<p>Abstract</p> <p>Background</p> <p>Sialidase is a well-known virulence factor of other respiratory pathogens, but was only recently documented to occur in some species of <it>Mycoplasma</it>. The sialidase activity expressed can vary quantitatively among strains within a species of mycoplasma, from undetectable to amounts that correlate positively with strain virulence. Very few isolates of <it>Mycoplasma pneumoniae </it>had ever been examined for sialidase activity, so it was unknown whether sialidase may contribute to diseases involving this species.</p> <p>Findings</p> <p>No sialidase activity was detected by spectrofluorometric assay of 15 laboratory strains and 91 clinical isolates of <it>M. pneumoniae </it>banked over many years from patients having radiologically-confirmed, uncomplicated community-acquired pneumonia.</p> <p>Conclusions</p> <p>The annotated genome of strain M129 (GenBank <ext-link ext-link-id="NC_000912" ext-link-type="gen">NC_000912</ext-link>, <ext-link ext-link-id="ATCC29342" ext-link-type="gen">ATCC 29342</ext-link>), also isolated from a patient with pneumonia, accurately represents the absence of sialidase genes from strains of <it>M. pneumoniae </it>typically associated with uncomplicated community-acquired pneumonia. A possible involvement of sialidase in neurologic or other extra-respiratory manifestations of <it>M. pneumoniae </it>mycoplasmosis remains to be investigated.</p

XMM-Newton observations of the sigma Ori cluster. II. Spatial and spectral analysis of the full EPIC field

We present the results of an XMM-Newton observation of the young (~2-4 Myr) cluster around the hot star sigma Orionis. In a previous paper we presented the analysis of the RGS spectrum of the central hot star; here we discuss the results of the analysis of the full EPIC field. We have detected 175 X-ray sources, 88 of which have been identified with cluster members, including very low-mass stars down to the substellar limit. We detected eleven new possible candidate members from the 2MASS catalogue. We find that late-type stars have a median log L_X/L_bol ~ -3.3, i.e. very close to the saturation limit. We detected significant variability in ~40% of late-type members or candidates, including 10 flaring sources; rotational modulation is detected in one K-type star and possibly in another 3 or 4 stars. Spectral analysis of the brightest sources shows typical quiescent temperatures in the range T_1 ~ 0.3-0.8 keV and T_2 ~ 1-3 keV, with subsolar abundances Z ~ 0.1-0.3 Z_sun, similar to what is found in other star-forming regions and associations. We find no significant difference in the spectral properties of classical and weak-lined T Tauri stars, although classical T Tauri stars tend to be less X-ray luminous than weak-lined T Tauri stars.Comment: 20 pages, 10 figures, 6 tables. Accepted by A&