Accretion-ejection connection in the young brown dwarf candidate ISO-Cha1 217

As the number of observed brown dwarf outflows is growing it is important to investigate how these outflows compare to the well studied jets from young stellar objects. A key point of comparison is the relationship between outflow and accretion activity and in particular the ratio between the mass outflow and accretion rates ($\dot{M}_{out}$/$\dot{M}_{acc}$). The brown dwarf candidate ISO-ChaI 217 was discovered by our group, as part of a spectro-astrometric study of brown dwarfs, to be driving an asymmetric outflow with the blue-shifted lobe having a position angle of $\sim$ 20$^{\circ}$. The aim here is to further investigate the properties of ISO-ChaI 217, the morphology and kinematics of its outflow, and to better constrain ($\dot{M}_{out}$/$\dot{M}_{acc}$). The outflow is spatially resolved in the $[SII]\lambda \lambda 6716,6731$ lines and is detected out to $\sim$ 1\farcs6 in the blue-shifted lobe and ~ 1" in the red-shifted lobe. The asymmetry between the two lobes is confirmed although the velocity asymmetry is less pronounced with respect to our previous study. Using thirteen different accretion tracers we measure log($\dot{M}_{acc}$) [M$_{sun}$/yr]= -10.6 $\pm$ 0.4. As it was not possible to measure the effect of extinction on the ISO-ChaI 217 outflow $\dot{M}_{out}$ was derived for a range of values of A$_{v}$, up to a value of A$_{v}$ = 2.5 mag estimated for the source extinction. The logarithm of the mass outflow ($\dot{M}_{out}$) was estimated in the range -11.7 to -11.1 for both jets combined. Thus $\dot{M}_{out}$/$\dot{M}_{acc}$ [\Msun/yr] lies below the maximum value predicted by magneto-centrifugal jet launching models. Finally, both model fitting of the Balmer decrements and spectro-astrometric analysis of the H$\alpha$ line show that the bulk of the H I emission comes from the accretion flow.Comment: accepted by Astronomy & Astrophysic

Supporting Coordinators of Large Units An Integrated, Team Approach - The OK Caral Model – From Peru’s Sandy Caral To Academe’s Stony Walls - Collaboration for Professional Development is OK!

In 2001, the Queensland University of Technology (QUT) Teaching and Learning Committee approved funding for a professional development program for Coordinators of Large Units (CLU) for 2002. This program is jointly facilitated by the Human Resources Department (HR) and Teaching and Learning Support Services (TALSS). The program is unique in both its focus and the way it has harnessed the distinct development responsibilities of two departments – HR for development in management and leadership and TALSS for development in teaching and learning. The CLU program facilitation team comprises two staff members from each Department along with joint administrative support. The focus of the CLU program is twofold: a) to support CLUs as a staff cohort with unique and specific needs and b) to acknowledge and make visible the systemic issues associated with teaching large groups of students

Continuous-flow laboratory simulation of stream water quality changes downstream of an untreated wastewater discharge.

In regions of the world with poor provision of wastewater treatment, raw sewage is often discharged directly into surface waters. This paper describes an experimental evaluation of the fate of two organic chemicals under these conditions using an artificial channel cascade fed with a mix of settled sewage and river water at its upstream end and operated under continuous steady-state conditions. The experiments underpin an environmental risk assessment methodology based on the idea of an “impact zone” (IZ) – the zone downstream of wastewater emission in which water quality is severely impaired by high concentrations of unionised ammonia, nitrite and biochemical oxygen demand (BOD). Radiolabelled dodecane-6-benzene sulphonate (DOBS) and aniline hydrochloride were used as the model chemical and reference compound respectively. Rapid changes in 14C counts were observed with flow-time for both these materials. These changes were most likely to be due to complete mineralisation. A dissipation half-life of approximately 7.1 h was observed for the 14C label with DOBS. The end of the IZ was defined as the point at which the concentration of both unionised ammonia and nitrite fell below their respective predicted no-effect concentrations for salmonids. At these points in the cascade, approximately 83 and 90% of the initial concentration of 14C had been removed from the water column, respectively. A simple model of mineral nitrogen transformations based on Michaelis–Menten kinetics was fitted to observed concentrations of NH4, NO2 and NO3. The cascade is intended to provide a confirmatory methodology for assessing the ecological risks of chemicals under direct discharge co

Searching for Galactic White Dwarf Binaries in Mock LISA Data using an F-Statistic Template Bank

We describe an F-statistic search for continuous gravitational waves from galactic white-dwarf binaries in simulated LISA Data. Our search method employs a hierarchical template-grid based exploration of the parameter space. In the first stage, candidate sources are identified in searches using different simulated laser signal combinations (known as TDI variables). Since each source generates a primary maximum near its true "Doppler parameters" (intrinsic frequency and sky position) as well as numerous secondary maxima of the F-statistic in Doppler parameter space, a search for multiple sources needs to distinguish between true signals and secondary maxima associated with other, "louder" signals. Our method does this by applying a coincidence test to reject candidates which are not found at nearby parameter space positions in searches using each of the three TDI variables. For signals surviving the coincidence test, we perform a fully coherent search over a refined parameter grid to provide an accurate parameter estimation for the final candidates. Suitably tuned, the pipeline is able to extract 1989 true signals with only 5 false alarms. The use of the rigid adiabatic approximation allows recovery of signal parameters with errors comparable to statistical expectations, although there is still some systematic excess with respect to statistical errors expected from Gaussian noise. An experimental iterative pipeline with seven rounds of signal subtraction and re-analysis of the residuals allows us to increase the number of signals recovered to a total of 3419 with 29 false alarms.Comment: 29 pages, 11 figures; submitted to Classical and Quantum Gravit

Cannabinoid signalling in TNF-alpha induced IL-8 release

Original article can be found at: http://www.sciencedirect.com/science/journal/00142999 Copyright Elsevier B.V. DOI : 10.1016/j.ejphar.2006.04.015Peer reviewe

F-statistic search for white-dwarf binaries in the first Mock LISA Data Challenge

The F-statistic is an optimal detection statistic for continuous gravitational waves, i.e. long-duration (quasi-)monochromatic signals with slowlyvarying intrinsic frequency. This method was originally developed in the context of ground-based detectors, but it is equally applicable to LISA where many signals fall into this class of signals. We report on the application of a LIGO/GEO Fstatistic code to LISA data-analysis using the long-wavelength limit (LWL), and we present results of our search for white-dwarf binary signals in the ¯rst Mock LISA Data Challenge. Somewhat surprisingly, the LWL is found to be su±cient { even at high frequencies { for detection of signals and their accurate localization on the sky and in frequency, while a more accurate modelling of the TDI response only seems necessary to correctly estimate the four amplitude parameters

Meiotic sex chromosome cohesion and autosomal synapsis are supported by Esco2.

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion

Technology that Touches Lives: Teleconsultation to Benefit Persons with Upper Limb Loss

While over 1.5 million individuals are living with limb lossin the United States (Ziegler-Graham et al., 2008), only 10% of these individuals have a loss that affects an upper limb. Coincident with the relatively low incidence of upper limb loss, is a shortage of the community-based prosthetic rehabilitation experts that can help prosthetic users to more fully integrate their devices into their daily routines. This article describes how expert prosthetists and occupational therapists at Touch Bionics, a manufacturer of advanced upper limb prosthetic devices, employ Voice over the Internet Protocol (VoIP) videoconferencing software telehealth technologies to engage in remote consultation with users of prosthetic devices and/or their local practitioners. The Touch Bionics staff provide follow-up expertise to local prosthetists, occupational therapists, and other health professionals. Contrasted with prior telephone-based consultations, the video-enabled approach provides enhanced capabilities to benefit persons with upper limb loss.  Currently, the opportunities for Touch Bionics occupational therapists to fully engage in patient-based services delivered through telehealth technologies are significantly reduced by their need to obtain and maintain professional licenses in multiple states