Binary open clusters in the Milky Way: photometric and spectroscopic analysis of NGC 5617 and Trumpler 22

Using photometry and high resolution spectroscopy we investigate for the first time the physical connection between the open clusters NGC 5617 and Trumpler 22. Based on new CCD photometry we report their spatial proximity and common age of ~70 Myr. Based on high resolution spectra collected using the HERMES and UCLES spectrographs on the Anglo-Australian telescope, we present radial velocities and abundances for Fe, Na, Mg, Al, Si, Ca and Ni. The measured radial velocities are -38.63 +/-2.25 km/s for NGC 5617 and -38.46 +/-2.08 km/s for Trumpler 22. The mean metallicity of NGC 5617 was found to be [Fe/H] =-0.18 +/-0.02 and for Trumpler 22 was found to be [Fe/H] = -0.17 +/-0.04. The two clusters share similar abundances across the other elements, indicative of a common chemical enrichment history of these clusters. Together with common motions and ages we confirm that NGC 5617 and Trumpler 22 are a primordial binary cluster pair in the Milky Way.Comment: 7 pages, 3 figure, accepted by MNRA

CN anomalies in the halo system and the origin of globular clusters in the Milky Way

We explore the kinematics and orbital properties of a sample of red giants in the halo system of the Milky Way that are thought to have formed in globular clusters based on their anomalously strong UV/blue CN bands. The orbital parameters of the CN-stron

Medical Imaging Utilization Trends in Radiation Oncology over the Past Decade

Purpose/Objective(s): We quantify the increase in use of pre-treatment imaging and verification imaging in radiation oncology over the past decade. We also quantify the trend towards hypofractionation, which has partially led to increased imaging. Materials/Methods: The pre-treatment and verification imaging data used are from a single, tertiary, university-affiliated cancer center. Pre-treatment imaging was defined as magnetic resonance imaging (MRI), positron emission tomography (PET) and four-dimensional computed tomography (4DCT). Verification imaging was defined as cone-beam computed tomography (CBCT). All treatment approved plans were included from 2012 to 2021. Data extraction was performed using custom scripts interfacing with the treatment planning system (TPS) and patient information system. All registered image-sets of planning CT images with either advanced pre-treatment advanced imaging or verification images in the TPS were included. Hypofractionation sub-analysis was performed according to plans above and below 4 Gy per fraction that received a combination of pre-treatment and verification imaging. Results: Between 2012 and 2021, a total of 42,214 plans were included. In 2021, MRI, PET, and 4DCT pre-treatment imaging modalities were used for 14%, 5%, and 3% of patients, respectively, which was an increase from 5%, 2%, and 0%, in 2012. In 2021, 55% of patients received CBCT for verification imaging compared to only 2% of patients in 2012. In the sub-analysis, cohort receiving greater than or equal to 4 Gy per fraction from 2012 to 2021, the percent of patients receiving one of MRI or PET for pre-treatment imaging and CBCT guidance for verification imaging increased from 1% to 22%. For the cohort receiving less than 4 Gy per fraction, there was an increase from 2012 to 2021 of 0% to 14% of patients receiving at least one of MRI or PET pretreatment imaging and CBCT for verification imaging. Table 1: Annual use of advanced pre-treatment, verification imaging, hypofractionation, and associated combination imaging shown. Entries indicate the percent (%) of patients per year with the imaging modality used in their treatment. Conclusion: An increase in the adoption of advanced medical imaging was observed in standard of care treatments over the past 10 years. Imaging utilization continues to increase as clinical trial evidence matures. Further analysis could focus on the gap between desired standard of care for patients and the current offerings as well as the increase in capital and human resource requirement for implementation of these advancements

The Asymptotic Giant Branches of GCs: Selective Entry Only

The handful of available observations of AGB stars in Galactic Globular Clusters suggest that the GC AGB populations are dominated by cyanogen-weak stars. This contrasts strongly with the distributions in the RGB (and other) populations, which generally show a 50:50 bimodality in CN band strength. If it is true that the AGB populations show very different distributions then it presents a serious problem for low mass stellar evolution theory, since such a surface abundance change going from the RGB to AGB is not predicted by stellar models. However this is only a tentative conclusion, since it is based on very small AGB sample sizes. To test whether this problem really exists we have carried out an observational campaign specifically targeting AGB stars in GCs. We have obtained medium resolution spectra for about 250 AGB stars across 9 Galactic GCs using the multi-object spectrograph on the AAT (2df/AAOmega). We present some of the preliminary findings of the study for the second parameter trio of GCs: NGC 288, NGC 362 and NGC 1851. The results indeed show that there is a deficiency of stars with strong CN bands on the AGB. To confirm that this phenomenon is robust and not just confined to CN band strengths and their vagaries, we have made observations using FLAMES/VLT to measure elemental abundances for NGC 6752.We present some initial results from this study also. Our sodium abundance results show conclusively that only a subset of stars in GCs experience the AGB phase of evolution. This is the first direct, concrete confirmation of the phenomenon.Comment: 4 pages, to appear in conference proceedings of "Reading the book of globular clusters with the lens of stellar evolution", Rome, 26-28 November 201

Brief behavioural activation for adolescent depression: working with complexity and risk

Given the long-term negative outcomes associated with depression in adolescence, there is a pressing need to develop brief, evidence based treatments that are accessible to more young people experiencing low mood. Behavioural Activation (BA) is an effective treatment for adult depression, however little research has focused on the use of BA with depressed adolescents, particularly with briefer forms of BA. In this article we outline an adaptation of brief Behavioral Activation Treatment of Depression (BATD) designed for adolescents and delivered in eight sessions (Brief BA). This case example illustrates how a structured, brief intervention was useful for a depressed young person with a number of complicating and risk factors

Building the Galactic halo from globular clusters: evidence from chemically unusual red giants

We present a spectroscopic search for halo field stars that originally formed in globular clusters. Using moderate-resolution SDSS-III/SEGUE-2 spectra of 561 red giants with typical halo metallicities (-1.8 < [Fe/H] < -1.0), we identify 16 stars, 3% of the sample, with CN and CH bandstrength behavior indicating depleted carbon and enhanced nitrogen abundances relative to the rest of the data set. Since globular clusters are the only environment known in which stars form with this pattern of atypical light-element abundances, we claim that these stars are second-generation globular cluster stars that have been lost to the halo field via normal cluster mass-loss processes. Extrapolating from theoretical models of two-generation globular cluster formation, this result suggests that globular clusters contributed significant numbers of stars to the construction of the Galactic halo: we calculate that a minimum of 17% of the present-day mass of the stellar halo was originally formed in globular clusters. The ratio of CN-strong to CN-normal stars drops with Galactocentric distance, suggesting that the inner-halo population may be the primary repository of these stars.Comment: 9 pages including 8 figures, A&A accepte

The Impact of Implementing Hypofractionation Prescription Regimens and Modernizing Delivery Technique on Treatment Resources in Breast Radiotherapy

Purpose/Objective(s): To determine the change in treatment resources due to the implementation of hypofractionated prescription regimen. Materials/Methods: All patients between January 1, 2012 and December 31, 2021 receiving curative intent breast radiotherapy at a tertiary cancer center were included. Plan and patient data were extracted from the patient database with the treatment planning system and direct database query. Treatment plan categorization was completed using data elements to include only curative intent. Treatment plans for seroma boost or supraclavicular irradiation were excluded to ensure this analysis did not double-count regional nodal irradiation contribution or confound boost with hypofractionation. Treatment delivery time is recorded in the database for each patient treatment delivered. Average patient treatment time per year was estimated by multiplying the average fractions each year by average time in the same year. The standard fractionation regimens (95% of patients) are 42.56 Gy in 16, 40 Gy in 16, 27 Gy in 5 (accelerated partial breast irradiation), and 26 Gy in 5 (FAST-Forward). In the analysis, implementation milestones are indicated for new prescription regimens and delivery technique changes including deep inspiration breath hold (DIBH) for left-sided patient treatments and daily verification imaging. Results: A total of 6505 patients were included. Table 1 details the total number of patients per year, the average number of fractions treated per patient, and the average treatment time of each patient plan. The average total fractions per treatment decreased from 17.5 in 2012 to 10.9 in 2021. The average treatment delivery time increased from 12.9 minutes to 21.4 minutes. Conclusion: In considering total treatment resources, the interplay between hypofractionation and modernization delivery techniques is complex. The impact of hypofractionation reduced the average number of fractions but total treatment resources are offset with the implementation of modern treatment delivery techniques. Hypofractionated prescription regimens reduce the time and travel commitment required of patients on an individual basis, contributing to person-centered care

Mass Segregation in the Globular Cluster Palomar 5 and its Tidal Tails

We present the stellar main sequence luminosity function (LF) of the disrupted, low-mass, low-concentration globular cluster Palomar 5 and its well-defined tidal tails, which emanate from the cluster as a result of its tidal interaction with the Milky Way. The results of our deep (B ~ 24.5) wide-field photometry unequivocally indicate that preferentially fainter stars were removed from the cluster so that the LF of the cluster's main body exhibits a significant degree of flattening compared to other globular clusters. There is clear evidence of mass segregation, which is reflected in a radial variation of the LFs. The LF of the tidal tails is distinctly enhanced with faint, low-mass stars. Pal 5 exhibits a binary main sequence, and we estimate a photometric binary frequency of roughly 10%. Also the binaries show evidence of mass segregation with more massive binary systems being more strongly concentrated toward the cluster center.Comment: 14 pages, 12 figures, accepted for publication in the Astronomical Journa