The Luminosity Function for L>L* Galaxies at z > 3

Through use of multiband (U, B, R, I) photometry we have isolated high redshift (3.0<z<3.5) galaxy candidates in a survey of 1.27 deg^2 to R = 21.25 and a survey of 0.02 deg^2 to R = 23.5. Our pool of candidates constrains the nature of the 3.0 < z < 3.5 luminosity function over the range L* < L < 100 L*, if we grant a similar level of completeness to these data as for very faint samples (to R = 25.5) selected in a similar fashion. Our constraints agree with the high redshift sky density at R = 20.5 estimated from Yee et al.'s (1996) serendipitous discovery of a bright, z = 2.7 galaxy, as well as the density at R ~ 23 by Steidel et al. (1996b). We strongly rule out -- by more than two orders of magnitude at M(R) = -25 -- the L > L* luminosity function for z = 3-5 galaxies obtained by a photometric redshift analysis of the Hubble Deep Field (HDF) by Gwyn & Hartwick (1996). Our results at R ~ 23 are more consistent with the photometric redshift analysis of the faint HDF galaxies by Sawicki & Yee (1996), but our present upper limits at the brightest magnitudes (R < 21.5, M(R) < -24) allow more generous volume densities of these super-L* galaxies.Comment: Accepted for publication in ApJ Letters; 14 pages Latex, including 3 figure

Measurement of radiotherapy x-ray skin dose on a chest wall phantom

Sufficient skin dose needs to be delivered by a radiotherapy chest wall treatment regimen to ensure the probability of a near surface tumor recurrence is minimized. To simulate a chest wall treatment a hemicylindrical solid water phantom of 7.5 cm radius was irradiated with 6 MV x-rays using 20×20 cm2 and 10×20 cm2 fields at 100 cm source surface distance (SSD) to the base of the phantom. A surface dose profile was obtained from 0 to 180°, in 10° increments around the circumference of the phantom. Dosimetry results obtained from radiochromic film (effective depth of 0.17 mm) were used in the investigation, the superficial doses were found to be 28% (of Dmax) at the 0° beam entry position and 58% at the 90° oblique beam position. Superficial dose results were also obtained using extra thin thermoluminescent dosimeters (TLD) (effective depth 0.14 mm) of 30% at 0°, 57% at 90°, and a metal oxide semiconductor field effect transistor (MOSFET) detector (effective depth 0.5 mm) of 43% at 0°, 62% at 90°. Because the differences in measured superficial doses were significant and beyond those related to experimental error, these differences are assumed to be mostly attributable to the effective depth of measurement of each detector. We numerically simulated a bolus on/bolus off technique and found we could increase the coverage to the skin. Using an alternate “bolus on,” “bolus off” regimen, the skin would receive 36.8 Gy at 0° incidence and 46.4 Gy at 90° incidence for a prescribed midpoint dose of 50 Gy. From this work it is evident that, as the circumference of the phantom is traversed the SSD increases and hence there is an inverse square fluence fall-off, this is more than offset by the increase in skin dose due to surface curvature to a plateau at about 90°. Beyond this angle it is assumed that beam attenuation through the phantom and inverse square fall-off is causing the surface dose to reduce

Reinitiation of compensatory lung growth after subsequent lung resection

ObjectiveIn experimental animals, pneumonectomy results in rapid, hyperplastic compensatory growth of the remaining lung. The limits of this induced growth are unknown. We tested the hypothesis that compensatory growth can be reinitiated in the same lung after subsequent lung resection.MethodsA left thoracotomy (Sham group) or left pneumonectomy (PNX group) was performed in Sprague–Dawley rats. A third group underwent left pneumonectomy followed 4 weeks later by a bilobectomy of the right upper and middle lobes (PNX+LBX group). Four weeks after bilobectomy in the PNX+LBX group (8 weeks in the Sham and PNX groups), right ventricular pressures were measured by using the open chest technique, and total lung weight and lower plus cardiac lobe weight indices were measured. Lungs were inflation fixed at 25 cm H2O to measure lobe volume index and to perform morphometric measurements on lung sections. Right ventricle/left ventricle plus septum weight index was measured as another index of pulmonary hypertension.ResultsTotal lung weight index was similar in all groups. Pneumonectomy resulted in increased lower plus cardiac lobe weight and volume indices, which were significantly augmented in the PNX+LBX group. The PNX+LBX group underwent a significant increase in total volume of respiratory region, airspace, and tissue and a decrease in alveolar surface density versus the PNX group. The PNX+LBX group also had significantly increased right ventricular systolic pressure and right ventricle/left ventricle plus septum index.ConclusionThese results demonstrate that compensatory growth can be reinitiated in lungs that had previously undergone postpneumonectomy compensatory growth. This subsequent growth, however, is more hypertrophic, and pulmonary hypertension develops despite subsequent compensatory growth

Cultural respect encompassing simulation training: being heard about health through broadband

Background. Cultural Respect Encompassing Simulation Training (CREST) is a learning program that uses simulation to provide health professional students and practitioners with strategies to communicate sensitively with culturally and linguistically diverse (CALD) patients. It consists of training modules with a cultural competency evaluation framework and CALD simulated patients to interact with trainees in immersive simulation scenarios. The aim of this study was to test the feasibility of expanding the delivery of CREST to rural Australia using live video streaming; and to investigate the fidelity of cultural sensitivity – defined within the process of cultural competency which includes awareness, knowledge, skills, encounters and desire – of the streamed simulations. Design and Methods. In this mixed-methods evaluative study, health professional trainees were recruited at three rural academic campuses and one rural hospital to pilot CREST sessions via live video streaming and simulation from the city campus in 2014. Cultural competency, teaching and learning evaluations were conducted. Results. Forty-five participants rated 26 reliable items before and after each session and reported statistically significant improvement in 4 of 5 cultural competency domains, particularly in cultural skills (P<0.05). Qualitative data indicated an overall acknowledgement amongst participants of the importance of communication training and the quality of the simulation training provided remotely by CREST. Conclusions. Cultural sensitivity education using live video-streaming and simulation can contribute to health professionals’ learning and is effective in improving cultural competency. CREST has the potential to be embedded within health professional curricula across Australian universities to address issues of health inequalities arising from a lack of cultural sensitivity training

Optically Faint Microjansky Radio Sources

We report on the identifications of radio sources from our survey of the Hubble Deep Field and the SSA13 fields, both of which comprise the deepest radio surveys to date at 1.4 GHz and 8.5 GHz respectively. About 80% of the microjansky radio sources are associated with moderate redshift starburst galaxies or AGNs within the I magnitude range of 17 to 24 with a median of I = 22 mag. Thirty-one (20%) of the radio sources are: 1) fainter than $I>$25 mag, with two objects in the HDF $I_{AB}>$28.5, 2) often identified with very red objects $I-K>$4, and 3) not significantly different in radio properties than the brighter objects. We suggest that most of these objects are associated with heavily obscured starburst galaxies with redshifts between 1 and 3. However, other mechanisms are discussed and cannot be ruled out with the present observations.Comment: to appear in Astrophysical Journal Letters, 3 figures, 1 tabl

Adenosine A1 receptor activation attenuates lung ischemia–reperfusion injury

ObjectivesIschemia–reperfusion injury contributes significantly to morbidity and mortality in lung transplant patients. Currently, no therapeutic agents are clinically available to prevent ischemia–reperfusion injury, and treatment strategies are limited to maintaining oxygenation and lung function. Adenosine can modulate inflammatory activity and injury by binding to various adenosine receptors; however, the role of the adenosine A1 receptor in ischemia–reperfusion injury and inflammation is not well understood. The present study tested the hypothesis that selective, exogenous activation of the A1 receptor would be anti-inflammatory and attenuate lung ischemia–reperfusion injury.MethodsWild-type and A1 receptor knockout mice underwent 1 hour of left lung ischemia and 2 hours of reperfusion using an in vivo hilar clamp model. An A1 receptor agonist, 2-chloro-N6-cyclopentyladenosine, was administered 5 minutes before ischemia. After reperfusion, lung function was evaluated by measuring airway resistance, pulmonary compliance, and pulmonary artery pressure. The wet/dry weight ratio was used to assess edema. The myeloperoxidase and cytokine levels in bronchoalveolar lavage fluid were measured to determine the presence of neutrophil infiltration and inflammation.ResultsIn the wild-type mice, 2-chloro-N6-cyclopentyladenosine significantly improved lung function and attenuated edema, cytokine expression, and myeloperoxidase levels compared with the vehicle-treated mice after ischemia–reperfusion. The incidence of lung ischemia–reperfusion injury was similar in the A1 receptor knockout and wild-type mice; and 2-chloro-N6-cyclopentyladenosine had no effects in the A1 receptor knockout mice. In vitro treatment of neutrophils with 2-chloro-N6-cyclopentyladenosine significantly reduced chemotaxis.ConclusionsExogenous A1 receptor activation improves lung function and decreases inflammation, edema, and neutrophil chemotaxis after ischemia and reperfusion. These results suggest a potential therapeutic application for A1 receptor agonists for the prevention of lung ischemia–reperfusion injury after transplantation

Optical Spectroscopy of Active Galactic Nuclei in SA57

The cosmological evolution of X-ray-selected and optically selected Active Galactic Nuclei (AGNs) show different behaviours interpreted in terms of two different populations. The difference is evident mainly for low luminosity AGNs (LLAGNs), many of which are lost by optical photometric surveys. We are conducting a spectroscopical study of a composite sample of AGN candidates selected in SA57 following different searching techniques, to identify low luminosity AGNs and break down the sample into different classes of objects. AGN candidates were obtained through optical variability and/or X-ray emission. Of special interest are the extended variable objects, which are expected to be galaxies hosting LLAGNs. Among the 26 classified objects a fair number (9) show typical AGN spectra. 10 objects show Narrow Emission Line Galaxy spectra, and in most of them (8/10) optical variability suggests the presence of LLAGNs.Comment: 7 pages, 8 figures, to appear in A&

Cl 1205+44, a fossil group at z = 0.59

This is a report of Chandra, XMM-Newton, HST and ARC observations of an extended X-ray source at z = 0.59. The apparent member galaxies range from spiral to elliptical and are all relatively red (i'-Ks about 3). We interpret this object to be a fossil group based on the difference between the brightness of the first and second brightest cluster members in the i'-band, and because the rest-frame bolometric X-ray luminosity is about 9.2x10^43 h70^-2 erg s^-1. This makes Cl 1205+44 the highest redshift fossil group yet reported. The system also contains a central double-lobed radio galaxy which appears to be growing via the accretion of smaller galaxies. We discuss the formation and evolution of fossil groups in light of the high redshift of Cl 1205+44.Comment: 21 pages, 13 figures, minor corrections to match published ApJ versio

Internal kinematics of spiral galaxies in distant clusters. Part II. Observations and data analysis

We have conducted an observing campaign with FORS at the ESO-VLT to explore the kinematical properties of spiral galaxies in distant galaxy clusters. Our main goal is to analyse transformation- and interaction processes of disk galaxies within the special environment of clusters as compared to the hierarchical evolution of galaxies in the field. Spatially resolved MOS-spectra have been obtained for seven galaxy clusters at 0.3<z<0.6 to measure rotation velocities of cluster members. For three of the clusters, Cl0303+17, Cl0413-65, and MS1008-12, for which we presented results including a TF-diagram in Ziegler et al. 2003, we describe here in detail the observations and data analysis. Each of them was observed with two setups of the standard FORS MOS-unit.With typical exposure times of >2 hours we reach an S/N>5 in the emission lines appropriate for the deduction of the galaxies' internal rotation velocities from [OII], Hbeta, or [OIII] profiles. Preselection of targets was done on the basis of available redshifts as well as from photometric and morphological information gathered from own observations, archive data, and from the literature. Emphasis was laid on the definition of suitable setups to avoid the typical restrictions of the standard MOS unit for this kind of observations. In total we assembled spectra of 116 objects of which 50 turned out to be cluster members. Position velocity diagrams, finding charts as well as tables with photometric, spectral, and structural parameters of individual galaxies are presented.Comment: 18 pages, 6 figures, accepted for publication in Astronomy and Astrophysics. A version with full resolution figures can be downloaded from http://www.uni-sw.gwdg.de/~vwgroup/publications.htm