21 research outputs found
Three-integral multi-component dynamical models and simulations of the nuclear star cluster in NGC 4244
Adaptive optics observations of the flattened nuclear star cluster in the
nearby edge-on spiral galaxy NGC 4244 using the Gemini Near-Infrared Integral
Field Spectrograph (NIFS) have revealed clear rotation. Using these kinematics
plus 2MASS photometry we construct a series of axisymmetric two-component
particle dynamical models with our improved version of NMAGIC, a flexible
Chi^2-made-to-measure code. The models consist of a nuclear cluster disc
embedded within a spheroidal particle population. We find a mass for the
nuclear star cluster of M=1.6^+0.5_-0.2 x 10^7 M_sun within ~42.4 pc (2"). We
also explore the presence of an intermediate mass black hole and show that
models with a black hole as massive as M_bh = 5.0 x 10^5 M_sun are consistent
with the available data. Regardless of whether a black hole is present or not,
the nuclear cluster is vertically anisotropic (beta_z < 0), as was found with
earlier two-integral models. We then use the models as initial conditions for
N-body simulations. These simulations show that the nuclear star cluster is
stable against non-axisymmetric perturbations. We also explore the effect of
the nuclear cluster accreting star clusters at various inclinations. Accretion
of a star cluster with mass 13% that of the nuclear cluster is already enough
to destroy the vertical anisotropy, regardless of orbital inclination.Comment: Replaced with the version accepted for publication in MNRAS. 13
pages, 10 figures, 3 table
An Internet-based survey of factors influencing medical student selection of a general surgery career
Background: This study descriptively analyzes characteristics of general surgery residency and practice and their influence on student interest in surgical careers.
Methods: Fourth-year medical students were invited to complete an Internet-based survey. A 5-point Likert scale described characteristics of general surgery residency and practice influencing medical student specialty selection. The same characteristics of nonsurgical careers were evaluated for students entering other specialties.
Results: A convenience sample of 408 students from 16 medical schools completed the survey. All respondents viewed lifestyles of surgical residents and attending surgeons as negative influences on specialty selection. Workload during surgical residency negatively influenced all respondents’ interest in a surgical career. Role model identification and perceived personality fit were important in selection of all specialties.
Conclusions: Medical students who choose surgical careers are not deterred by a negative perception of lifestyle and workload considerations. Mentoring and personality fit are central in medical student specialty selection
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Fall risk and function in older women after gynecologic surgery
Purpose of study: To examine change in balance-related fall risk and daily functional abilities in the first 2 postoperative weeks and up to 6 weeks after gynecologic surgery. Materials and methods: Prospective cohort study in gynecologic surgery patients age 65 and older. Balance confidence (Activities-specific Balance Confidence Scale) and functional status (basic and instrumental activities of daily living) were recorded pre-and post-operatively daily for 1 week and twice the second week. Physical performance balance and functional mobility were measured pre-and 1 week post-operatively using the Tinetti Fall Risk Scale, Timed Up and Go, and 6-Minute Walk test. Measures were repeated 6 weeks after surgery. Nonparametric tests for paired data were used comparing scores baseline to post-operative (POD) 7 and to POD 42. Results: Median age was 72 years (range 65-88). Fall risk was elevated during the first 2 post-operative weeks, greatest on the median discharge day, POD 2 (p < 0.01). Balance performance and functional mobility at 1 week were significantly lower than baseline (p < 0.01). Functional abilities declined, including new dependence in medication management at home in 22% of these independent and cognitively intact women. Conclusions: After gynecologic surgery, older women's fall risk is highest on POD 2 and remains elevated from baseline for 2 weeks. Functional limitations in the early home recovery period include the anticipated (bathing, cooking, etc.) and some unanticipated (medication management) ones. This information may help with postoperative discharge planning.Published open access.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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The role of the Veterans Affairs Medical Centers in patient care, surgical education, research and faculty development
Veterans Administration (VA) medical centers have had a long history of providing medical care to those who have served their country. Over time, the VA has evolved into a facility that has had a major role in graduate medical education. In surgery, this had provided experience in the medical and surgical management of complex surgical disease involving the head and neck, chest, and gastrointestinal tract, and in the fields of surgical oncology, peripheral vascular disease, and the subspecialties of urology, orthopedics, and neurosurgery. The VA provides a venue for the attending physician and resident to work in concert to allow the resident to shoulder increasing accountability in decision-making and delivery of care in the outpatient arena, the operating room, and the intensive care unit. Medical students assigned to a VA hospital are afforded a great opportunity to be exposed to preoperative planning, discussions leading to informed consent for surgery, the actual operation, and postoperative care. Numerous opportunities at the VA are available for novice and experienced medical faculty members to develop and/or enhance skills and abilities in patient care, medical education, and research. In addition, the VA offers unique opportunities for academic physicians and other healthcare professionals to administer its many programs, thereby developing leadership skills and experience in the process. The VA is uniquely situated to design and conduct multicenter clinical trials. The most important aspect of this is the infrastructure provided by the VA Cooperative Studies Program. Of the four missions of the Department of Veterans Affairs, research and education is essential to provide quality, state of the art clinical care to the veteran. The National Surgical Quality Improvement Program (NSQIP) is an example of how outcomes based research can favorably impact on patient outcome. Looking across the horizon of information solutions available to surgeons, the options are limited. This is not the case for the Department of Veterans Affairs. With the congressionally mandated charge for the VA to compare its quality to private clinicians, the advent of the “Surgery Package” became possible. The VA will continue its leadership position in the healthcare arena if it can successfully address the challenges facing it
Pancreatic cancer as a sentinel for hereditary cancer predisposition
Background: Genes associated with hereditary breast and ovarian cancer (HBOC) and colorectal cancer (CRC) predisposition have been shown to play a role in pancreatic cancer susceptibility. Growing evidence suggests that pancreatic cancer may be useful as a sentinel cancer to identify families that could benefit from HBOC or CRC surveillance, but to date pancreatic cancer is only considered an indication for genetic testing in the context of additional family history. Methods: Preliminary data generated at the Huntsman Cancer Hospital (HCH) included variants identified on a custom 34-gene panel or 59-gene panel including both known HBOC and CRC genes for respective sets of 66 and 147 pancreatic cancer cases, unselected for family history. Given the strength of preliminary data and corresponding literature, 61 sequential pancreatic cancer cases underwent a custom 14-gene clinical panel. Sequencing data from HCH pancreatic cancer cases, pancreatic cancer cases of the Cancer Genome Atlas (TCGA), and an unselected pancreatic cancer screen from the Mayo Clinic were combined in a meta-analysis to estimate the proportion of carriers with pathogenic and high probability of pathogenic variants of uncertain significance (HiP-VUS). Results: Approximately 8.6% of unselected pancreatic cancer cases at the HCH carried a variant with potential HBOC or CRC screening recommendations. A meta-analysis of unselected pancreatic cancer cases revealed that approximately 11.5% carry a pathogenic variant or HiP-VUS. Conclusion: With the inclusion of both HBOC and CRC susceptibility genes in a panel test, unselected pancreatic cancer cases act as a useful sentinel cancer to identify asymptomatic at-risk relatives who could benefit from relevant HBOC and CRC surveillance measures.United States National Institutes of Health (NIH) National Cancer Institute (NCI) [R01CA164138]; NCI [P30CA042014]; Utah Genome Project; Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer program; Government of Canada through Genome Canada; Canadian Institutes of Health Research; Ministere de l'enseignement superieur, de la recherche, de la science, et de la technologie du Quebec through Genome Quebec; NIH NCI Cancer Center Support Grant [P30CA042014]; Huntsman Cancer Foundation; National Human Genome Research Institute [T32HG008962]Open access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]