First XMM-Newton observations of strongly magnetic cataclysmic variables I: spectral studies of DP Leo and WW Hor

We present an analysis of the X-ray spectra of two strongly magnetic cataclysmic variables, DP Leo and WW Hor, made using XMM-Newton. Both systems were in intermediate levels of accretion. Hard optically thin X-ray emission from the shocked accreting gas was detected from both systems, while a soft blackbody X-ray component from the heated surface was detected only in DP Leo. We suggest that the lack of a soft X-ray component in WW Hor is due to the fact that the accretion area is larger than in previous observations with a resulting lower temperature for the re-processed hard X-rays. Using a multi-temperature model of the post-shock flow, we estimate that the white dwarf in both systems has a mass greater than 1 Msun. The implications of this result are discussed. We demonstrate that the `soft X-ray excess' observed in many magnetic cataclysmic variables can be partially attributed to using an inappropriate model for the hard X-ray emission.Comment: Accepted by MNRAS as a letter, 5 pages, 2 figure

Targeting the tumor microenvironment in colorectal peritoneal metastases

Peritoneal metastasis (PM) occurs in approximately one in four colorectal cancer (CRC) patients. The pathophysiology of colorectal PM remains poorly characterized. Also, the efficacy of current treatment modalities, including surgery and intraperitoneal (IP) delivery of chemotherapy, is limited. Increasingly, therefore, efforts are being developed to unravel the PM cascade and at understanding the PM-associated tumor microenvironment (TME) and peritoneal ecosystem as potential therapeutic targets. Here, we review recent insights in the structure and components of the TME in colorectal PM, and discuss how these may translate into novel therapeutic approaches aimed at re-engineering the metastasis-promoting activity of the stroma

Relative effectiveness of robot-assisted and standard laparoscopic prostatectomy as alternatives to open radical prostatectomy for treatment of localised prostate cancer : a systematic review and mixed treatment comparison meta-analysis

© 2013 The Authors. BJU International © 2013 BJU International.Peer reviewedPublisher PD

First XMM-Newton observations of strongly magnetic cataclysmic variables - II. Timing studies of DP Leo and WW Hor

XMM-Newton was used to observe two eclipsing, magnetic cataclysmic variables, DP Leo and WW Hor, continuously for three orbital cycles each. Both systems were in an intermediate state of accretion. For WW Hor we also obtained optical light curves with the XMM-Newton Optical Monitor and from ground-based observations. Our analysis of the X-ray and optical light curves allows us to constrain physical and geometrical parameters of the accretion regions and derive orbital parameters and eclipse ephemerides of the systems. For WW Hor we directly measure horizontal and vertical temperature variations in the accretion column. From comparisons with previous observations we find that changes in the accretion spot longitude are correlated with the accretion rate. For DP Leo the shape of the hard X-ray light curve is not as expected for optically thin emission, showing the importance of optical depth effects in the post-shock region. We find that the spin period of the white dwarf is slightly shorter than the orbital period and that the orbital period is decreasing faster than expected for energy loss by gravitational radiation alone.Comment: Accepted for publication in MNRAS, 12 pages, 6 figure

Development of an Outcomes-Based Undergraduate Curriculum in Homeland Security

As a professional discipline, homeland security is complex, dynamic, and interdisciplinary and not given to facile definition. As an academic discipline, homeland security is relatively new and growing, and its workforce aging. As such, there is an acknowledged need to develop academic homeland security programs to try and meet anticipated workforce needs. However, the lack of an accreditation system or a set of available published outcomes (or standards) have complicated efforts towards homeland security program development. At present, determining which courses to teach and which outcomes in each course to pursue must be left to anecdotal conversations, reviews of the scant textbooks available, and idiosyncratic experience and judgment. Consequently, as homeland security programs have proliferated throughout the country even a cursory review of these programs on the Center for Homeland Defense and Security (CHDS) website reveals an uneven and inconsistent set of core student outcomes. Using practicing professionals in a variety of homeland security areas as subject matter experts, this study was designed to elucidate a set of core academic areas and student learning outcomes that could characterize the intellectual underpinnings of the discipline and the outcomes on which an undergraduate degree in homeland security could be based

The Effects of Furnishings and Technology on Pedagogical Agility and Student Engagement Across Flexible Learning Spaces

We explored how furnishings and technology impact pedagogical agility and student engagement across three flexible learning spaces. We collected various data sources from students and faculty teaching in multiple learning spaces, such as focus group interviews with students, faculty responses to reflection prompts, and pre-and post-occupancy surveys with faculty and students. Flexible furniture configuration was found to support various instructional strategies and facilitate interaction between student-student and student-instructor. A writable surface is beneficial to facilitate student engagement during group activities. Digital displays with content sharing capabilities promote collaborative learning. Specific recommendations for learning space designs and faculty development are provided