2,368 research outputs found

    Globular Cluster Systems in Brightest Cluster Galaxies. III: Beyond Bimodality

    Full text link
    We present new deep photometry of the rich globular cluster (GC) systems around the Brightest Cluster Galaxies UGC 9799 (Abell 2052) and UGC 10143 (Abell 2147), obtained with the HST ACS and WFC3 cameras. For comparison, we also present new reductions of similar HST/ACS data for the Coma supergiants NGC 4874 and 4889. All four of these galaxies have huge cluster populations (to the radial limits of our data, comprising from 12000 to 23000 clusters per galaxy). The metallicity distribution functions (MDFs) of the GCs can still be matched by a bimodal-Gaussian form where the metal-rich and metal-poor modes are separated by ~0.8 dex, but the internal dispersions of each mode are so large that the total MDF becomes very broad and nearly continuous from [Fe/H] = -2.4 to Solar. There are, however, significant differences between galaxies in the relative numbers of \emph{metal-rich} clusters, suggesting that they underwent significantly different histories of mergers with massive, gas-rich halos. Lastly, the proportion of metal-poor GCs rises especially rapidly outside projected radii R > 4 R_eff, suggesting the importance of accreted dwarf satellites in the outer halo. Comprehensive models for the formation of GCs as part of the hierarchical formation of their parent galaxies will be needed to trace the systematic change in structure of the MDF with galaxy mass, from the distinctly bimodal form in smaller galaxies up to the broad continuum that we see in the very largest systems.Comment: In press for Astrophysical Journa

    adjuvant mitotane for adrenocortical cancer working through uncertainty

    Get PDF
    The Journal of Clinical Endocrinology & Metabolism recently published a commentary by Huang and Fojo (1) offering a skeptical view on the efficacy of mitotane as an adjunctive postsurgical measure in patients with adrenocortical cancer (ACC). Their commentary focused on outlining the limitations of our recent study which indicated that adjuvant mitotane may prolong recurrence-free survival (RFS) in patients with radically resected ACC (2). However, we do not agree with several of their conclusions and believe that it is of interest to present our view for a balanced and comprehensive coverage of this important matter. Inprinciple,weagreewithHuangandFojothatourstudysuffers from the important limitation of a retrospective analysis; thus our investigation should be considered as hypothesis generating and certainly does not provide conclusive evidence. This problem has been clearly acknowledged in the paper, and we cautiously concluded that our study should renew interest in adjuvant therapy, whereas prospective, randomized trials will be needed to confirm the efficacyof adjuvantmitotane treatment (2).However, the rarity of ACC precluded organization of a randomized trial either in an adjuvantsettingor inpatientswithadvancedACC(3).Nonetheless, mitotane has been used for treating patients with ACC since the 1960s and is the only drug approved for ACC by the U.S. Food and Drug Administration and the European Medicines Evaluation Agency (4). In this scenario, a study including all consecutive patients treated postoperatively with mitotane in some centers and all consecutive patients left untreated after operation in other centers is thebestway toobtainexplorativedataon theefficacyofadjuvant mitotane, provided that the two groups are comparable. In our study, in fact, mitotane was recommended on the basis of the treatmentpolicyof thecenter, independentof thecharacteristicsofeither the tumorsor thepatients, and this is amajoradvantageminimizing selection bias as compared with other studies that had less clear treatment assignments (5). The major criticism of Huang and Fojo (1) is that we did not demonstrate any benefit on overall survival (OS) for patients treated adjuvantly. However, this is not correct because the hazard ratio of death of the German cohort of nontreated patients was nonsignificantly higher than mitotane-treated patients in univariate analysis, but the difference became significant in multivariate analysis after adjusting for imbalances in prognostic factors (the German cohort included more patients with stage I and II ACC than the Italian cohort of mitotane-treated patients). Even when we accept that the effect of adjuvant mitotane on OS was less impressive than on RFS, we disagree that prolonging a disease-free status is not a clinically meaningful objective even without extending significantly duration of life. In addition, there is a long-standing debate on the most appropriate endpoint for adjuvant trials, and both OS and RFS have been suggested. Analysis of RFS has the advantage of needing a shorter follow-up and being directly related to the treatment tested. The most important disadvantage of RFS is its close relationship to the frequency and quality of evaluation. Bias in follow-up or ascertainment of outcome in observational retrospective series is well recognized, and we have acknowledged this potential limit of our study. However, the follow-up procedures were highly comparable among the different centers and included imaging evaluation of the chest and abdomen every 6 months until disease progression or the end of the study period (2). Even if survival has to be considered as the reference end-point, it may not be a direct result of the study drug because it may be strongly influenced by subsequent treatments and oncologists are increasingly considering RFS as a valid surrogate for OS (6). However, this relationship has never been demonstrated specifically in ACC patients. Another criticism is derived from an ill-conceived reanalysis of our data. Huang and Fojo (1) aimed at demonstrating that the time interval between ACC recurrence and death is higher in patients treated adjuvantly than patients left untreated after surgery. Thus, they assumed important differences in tumor biology of the different cohorts. This conclusion comes from subtracting median time to recurrence from median survival observed in th

    Low-dose aspirin for primary prevention of cardiovascular events in postmenopausal women with type-2 diabetes: The prescriptive approach in the real world

    Get PDF
    Background: The long-Term efficacy of low-dose aspirin for primary prevention of cardiovascular (CV) events in postmenopausal women with type-2 diabetes is controversial. Therefore, it is recommended only on an individual basis, recommendation of grade C. Methods: We enrolled 275 consecutive postmenopausal women with type-2 diabetes, without an increased bleeding risk and without preexisting CV disease as coronary artery disease, stroke, and peripheral vascular disease, but with a high risk assessed by score >10%, aged 60-69 years. All were receiving aspirin (75-100 mg daily), aspirin group (AG). 170 postmenopausal women with type-2 diabetes and without preexisting cardiovascular (CV) disease, but not on aspirin treatment, despite a high risk assessed by score >10%, were control group (CG). Mean age was 66 ± 4 years for AG and 65 ± 7 years for CG. Our goal was to identify the prevalence of low-dose aspirin prescriptions in these populations according to different clinical conditions. Results: Women with only high risk were 41/275 (15%) on AG and 72/170 (42.3%) on CG, Chi-squared 41, Odds ratio 0.2, c.i. 95%, P < 0.0001. Women affected by metabolic syndrome were 105/275 (38.1%) on AG and 47/170 (27.6%) on CG, Chi-squared 5.1, Odds ratio 1.6, c.i. 95%, P < 0.02. Women affected by metabolic cardiomyopathy were 111/275 (40.3%) on AG and 44/170 (25.9%) on CG, Chi-squared 8, Odds ratio 1.8, c.i. 95%, P < 0.004. Women affected by diabetic cardiomyopathy were 18/275 (6.6%) on AG and 7/170 (4.2%) on CG, Chi-squared 1.2, Odds ratio 16, c.i. 95%, P < 0.2 n.s. Conclusions: Low-dose aspirin in our population is prescribed preferentially in postmenopausal women with type-2 diabetes when affected by metabolic syndrome or metabolic cardiomyopathy, at the opposite women with only high risk have lower chance to receive aspirin

    The Search For A Dog-Free Portfolio: Why Unions Matter To Investors

    Get PDF
    This paper uses portfolio filtering and weighting research to create a dog-free portfolio.&nbsp; The variables used to create the dog-free portfolio include level of unionization and book-to-market.&nbsp; The filtered and weighted portfolio is averaging 47 basis points alpha per month from 1991-2007 over the benchmark S&amp;P500, outperforming in 60.8% of the months.&nbsp; Using annual data, the portfolio averages 603 basis points alpha from 1991-2007 over the benchmark S&amp;P500, outperforming 82.4% of the time.&nbsp

    Autonomous Service Drones for Multimodal Detection and Monitoring of Archaeological Sites

    Get PDF
    Constant detection and monitoring of archaeological sites and objects have always been an important national goal for many countries. The early identification of changes is crucial to preventive conservation. Archaeologists have always considered using service drones to automate collecting data on and below the ground surface of archaeological sites, with cost and technical barriers being the main hurdles against the wide-scale deployment. Advances in thermal imaging, depth imaging, drones, and artificial intelligence have driven the cost down and improved the quality and volume of data collected and processed. This paper proposes an end-to-end framework for archaeological sites detection and monitoring using autonomous service drones. We mount RGB, depth, and thermal cameras on an autonomous drone for low-altitude data acquisition. To align and aggregate collected images, we propose two-stage multimodal depth-to-RGB and thermal-to-RGB mosaicking algorithms. We then apply detection algorithms to the stitched images to identify change regions and design a user interface to monitor these regions over time. Our results show we can create overlays of aligned thermal and depth data on RGB mosaics of archaeological sites. We tested our change detection algorithm and found it has a root mean square error of 0.04. To validate the proposed framework, we tested our thermal image stitching pipeline against state-of-the-art commercial software. We cost-effectively replicated its functionality while adding a new depth-based modality and created a user interface for temporally monitoring changes in multimodal views of archaeological sites

    The advantage of sleeve lobectomy over pneumonectomy

    Get PDF
    Answer to Dr. Ludwig about lower sleeve lobectomy, the so-called “Y” sleeve

    Case Report: Successful Staged Ureteroscopic Treatment of a 5 cm Staghorn Renal Calculus

    Get PDF
    It is widely accepted that percutaneous nephrostolithotorny (PCNL) is the standard of choice for the removal of large staghorn renal calculi. Although data exists supporting a stagad ureteroscopic as an alternate treatment for stones up to 3 cm in select patients, little data exists to support a ureteroscopic approach for stones as large as 5 cm. We present a case of a 68 year old female with a 5 cm staghorn renal calculus managed successfully with a staged ureteroscopic approach. A staged ureteroscopic approach can be effective in treating stones as large as 5 cm

    Regularized transport between singular covariance matrices

    Get PDF
    We consider the problem of steering a linear stochastic system between two end-point degenerate Gaussian distributions in finite time. This accounts for those situations in which some but not all of the state entries are uncertain at the initial, t = 0, and final time, t = T. This problem entails non-trivial technical challenges as the singularity of terminal state-covariance causes the control to grow unbounded at the final time T. Consequently, the entropic interpolation (Schroedinger Bridge) is provided by a diffusion process which is not finite-energy, thereby placing this case outside of most of the current theory. In this paper, we show that a feasible interpolation can be derived as a limiting case of earlier results for non-degenerate cases, and that it can be expressed in closed form. Moreover, we show that such interpolation belongs to the same reciprocal class of the uncontrolled evolution. By doing so we also highlight a time-symmetry of the problem, contrasting dual formulations in the forward and reverse time-directions, where in each the control grows unbounded as time approaches the end-point (in the forward and reverse time-direction, respectively)

    Continuous flow left ventricular assist devices do not worsen endothelial function in subjects with chronic heart failure: a pilot study

    Get PDF
    Aims: To evaluate endothelial function in subjects with left ventricular assist devices (LVADs), comparing them with subjects with chronic heart failure with reduced ejection fraction on the list for heart transplant (HT) and with HT patients with a normal systolic cardiac function to identify any differences. Methods: We enrolled 28 subjects with LVAD, 55 subjects with HT, and 42 subjects with heart failure on the transplant list. The subjects underwent a general physical examination, assessment of laboratory blood parameters, and assessment of endothelial function through flow-mediated dilation (FMD) of brachial artery. Results: The three groups were homogeneous as regards age, gender, smoke abuse, C-reactive protein (CRP) and FMD parameters (P&nbsp;=&nbsp;ns). In LVAD group percentage of FMD change showed an inverse correlation with CRP (rho: −0.5, P: 0.003), a well-known marker of inflammation and tissue damage. Conclusions: Continuous flow related to LVAD seems to not worsen endothelial function. Endothelial function was not affected by cardiovascular risk factors (hypertension, hypercholesterolaemia, diabetes, obesity, and tobacco habit), by the functional status expressed by New York Heart Association class, by the left ventricular systolic function and by the presence or absence of ischaemic heart disease in all the populations analysed. CRP was the only factor able to influence percentage of FMD change in patient with LVAD, reinforcing the hypothesis that inflammation is the main determinant of endothelial function
    corecore