198 research outputs found

    Magnetic Domain Structure of La0.7Sr0.3MnO3 thin-films probed at variable temperature with Scanning Electron Microscopy with Polarization Analysis

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    The domain configuration of 50 nm thick La0.7SrMnO3 films has been directly investigated using scanning electron microscopy with polarization analysis (SEMPA), with magnetic contrast obtained without the requirement for prior surface preparation. The large scale domain structure reflects a primarily four-fold anisotropy, with a small uniaxial component, consistent with magneto-optic Kerr effect measurements. We also determine the domain transition profile and find it to be in agreement with previous estimates of the domain wall width in this material. The temperature dependence of the image contrast is investigated and compared to superconducting-quantum interference device magnetometry data. A faster decrease in the SEMPA contrast is revealed, which can be explained by the technique's extreme surface sensitivity, allowing us to selectively probe the surface spin polarization which due to the double exchange mechanism exhibits a distinctly different temperature dependence than the bulk magnetization

    The Immersive Media Library @ VCU

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    Answering the call issued by John Underkoffler in 2010 about the future of UI, I have imagined the Immersive Media Library (IML) as an annex of the main VCU library, offering a concentration of visually immersive spaces to compliment the space the university is already building in the renovated Cabell Library. The design is new in that the emphasis is placed on the collaboration between librarians and visitors in creating new work. Focusing on the interpersonal might be unexpected from program with such an emphasis on new technology - but I see it as vital part of the new computing paradigm

    Fully Automatic Danger Zone Determination for SBRT in NSCLC

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    Lung cancer is the major cause of cancer death worldwide. The most common form of lung cancer is non-small cell lung cancer(NSCLC). Stereotactic body radiation therapy (SBRT) has emerged as a good alternative to surgery in patients with peripheralstage I NSCLC, demonstrating favorable tumor control and low toxicity. Due to spatial relationship to several critical organs atrisk, SBRT of centrally located lesions is associated with more severe toxicity and requires modification in dose application andfractionation, which is currently evaluated in clinical trials. Therefore a classification of lung tumors into central or peripheralis required. In this work we present a novel, highly versatile, mulitmodality tool for tumor classification which requires no userinteraction. Furthermore the tool can automatically segment the trachea, proximal bronchial tree, mediastinum, gross target volumeand internal target volume. The proposed work is evaluated on 19 cases with different image modalities assessing segmentationquality as well as classification accuracy. Experiments showed a good segmentation quality and a classification accuracy of 95 %.These results suggest the use of the proposed tool for clinical trials to assist clinicians in their work and to fasten up the workflowin NSCLC patients treatment

    A Characterization of Cancer Patients in Inpatient Rehabilitation Facilities: A Retrospective Cohort Study

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    OBJECTIVES: To identify the types of cancer patients admitted to inpatient medical rehabilitation and to describe their rehabilitation outcomes. DESIGN: Retrospective cohort study. SETTING: U.S. inpatient rehabilitation facilities (IRFs). PARTICIPANTS: Adult patients (N=27,952) with a malignant cancer diagnosis admitted to an IRF with a cancer-related impairment between October 2010 and September 2012 were identified from the Uniform Data System for Medical Rehabilitation database. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Demographic, medical, and rehabilitation characteristics for patients with various cancer tumor types were summarized using data collected from the Inpatient Rehabilitation Facility-Patient Assessment Instrument. Rehabilitation outcomes included the percentage of patients discharged to the community and acute care settings, and functional change from admission to discharge. Functional status was measured using the FIM instrument. RESULTS: Cancer patients constituted about 2.4% of the total IRF patient population. Cancer types included brain and nervous system (52.9%), digestive (12.0%), bone and joint (8.7%), blood and lymphatic (7.6%), respiratory (7.1%), and other (11.7%). Overall, 72% were discharged to a community setting, and 16.5% were discharged back to acute care. Patients with blood and lymphatic cancers had the highest frequency of discharge back to acute care (28%). On average, all cancer patient groups made significant functional gains during their IRF stay (mean FIM total change ± SD, 23.5±16.2). CONCLUSIONS: In a database representing approximately 70% of all U.S. patients in IRFs, we found that patients with a variety of cancer types are admitted to inpatient rehabilitation. Most cancer patients admitted to IRFs were discharged to a community setting and, on average, improved their function. Future research is warranted to understand the referral patterns of admission to postacute care rehabilitation and to identify factors that are associated with rehabilitation benefit in order to inform the establishment of appropriate care protocols

    The Cenozoic Climatic and Topographic Evolution of the Western North American Cordillera

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    Herein we present oxygen isotope records from Cretaceous to Recent terrestrial sediments in the western North American Cordillera. The purpose of this analysis is to use oxygen isotope records to understand the coupled surface elevation and climate histories of this region through the Cenozoic. To do this we constructed ÎŽÂč⁞(O) maps of surface waters for time intervals that trace the development of topography of western North America. These maps are based on 4861 oxygen isotope analyses from both published (4478) and new (383) data. We determined the ÎŽÂč⁞(O) values of surface waters using paleotemperatures derived previously from floral assemblages and the appropriate isotope fractionation factors. These data suggest that in the late Cretaceous to early Eocene the Sevier hinterland formed a plateau of unknown height. Around 50 Ma, a topographic wave developed in British Columbia and eastern Washington that swept southward reaching northeastern Nevada at ~40 to 38 Ma, and southern Nevada ~23 Ma. This southward encroachment of an Eocene Plateau (SWEEP) caused reorganization of drainage patterns such that the intraforeland basins of Wyoming and Utah drainages extended deep within the Sevier hinterland as the wave swept southward. The landscape within the Sevier hinterland developed into a rugged and high mountain range with the hypsometric mean elevation of ~4 km and relief of ~1.5 km. This Eocene highland was bordered on the west by a high Sierra Nevada ramp and on the east by the intraforeland basins that captured water draining these growing highlands. The spatial and temporal evolution of this highland correlates with the timing of volcanism and extension. These observations support tectonic models that call for north to south removal of the Farallon slab or piecemeal removal of mantle lithosphere. The isotopic data show that prior to growth of this highland the North American Monsoon (NAM) penetrated much farther north in the Paleocene/Eocene than today. The combined effects of global cooling, increasing latitudinal temperature gradients, and the generation of the orographic barrier created by the growing north to south highland produced a southward migration of the NAM front. By the Oligocene the hydrologic regime that we observe today was in place. It has been modified since then as a result of Basin and Range extension and collapse of the highlands in the mid-Miocene. This collapse allowed the NAM to penetrate farther north into the Great Basin of Nevada and Utah

    Arctic ocean chronology confirmed by accelerator 14C dating

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    The role of the Arctic Ocean in Earth's climatic and oceanographic development is significant but has become controversial because of disagreements concerning a reliable Arctic chronology. The first Arctic Ocean chronology based on U-Th and 14C data was in agreement with magnetostratigraphy developed later but these data have been challenged by recent amino acid diagenesis dates. New accelerator 14C data support the earlier U-Th-magnetostratigraphic dates and confirm the reliability of the established Arctic Ocean chronology

    A Study of the Diverse T Dwarf Population Revealed by WISE

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    We report the discovery of 87 new T dwarfs uncovered with the Wide-field Infrared Survey Explorer (WISE) and three brown dwarfs with extremely red near-infrared colors that exhibit characteristics of both L and T dwarfs. Two of the new T dwarfs are likely binaries with L7+/-1 primaries and mid-type T secondaries. In addition, our follow-up program has confirmed 10 previously identified T dwarfs and four photometrically-selected L and T dwarf candidates in the literature. This sample, along with the previous WISE discoveries, triples the number of known brown dwarfs with spectral types later than T5. Using the WISE All-Sky Source Catalog we present updated color-color and color-type diagrams for all the WISE-discovered T and Y dwarfs. Near-infrared spectra of the new discoveries are presented, along with spectral classifications. To accommodate later T dwarfs we have modified the integrated flux method of determining spectral indices to instead use the median flux. Furthermore, a newly defined J-narrow index differentiates the early-type Y dwarfs from late-type T dwarfs based on the J-band continuum slope. The K/J indices for this expanded sample show that 32% of late-type T dwarfs have suppressed K-band flux and are blue relative to the spectral standards, while only 11% are redder than the standards. Comparison of the Y/J and K/J index to models suggests diverse atmospheric conditions and supports the possible re-emergence of clouds after the L/T transition. We also discuss peculiar brown dwarfs and candidates that were found not to be substellar, including two Young Stellar Objects and two Active Galactic Nuclei. The coolest WISE-discovered brown dwarfs are the closest of their type and will remain the only sample of their kind for many years to come.Comment: Accepted to ApJS on 15 January 2013; 99 pages in preprint format, 30 figures, 12 table

    Evaluation of intensity modulated radiation therapy dose painting for localized prostate cancer using 68 Ga-HBED-CC PSMA-PET/CT: A planning study based on histopathology reference

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    AbstractPurposeTo demonstrate the feasibility and to evaluate the tumour control probability (TCP) and normal tissue complication probability (NTCP) of IMRT dose painting using 68Ga-HBED-CC PSMA PET/CT for target delineation in prostate cancer (PCa).Methods and materials10 patients had PSMA PET/CT scans prior to prostatectomy. GTV-PET was generated on the basis of an intraprostatic SUVmax of 30%. Two IMRT plans were generated for each patient: Plan77 which consisted of whole-prostate IMRT to 77Gy, and Plan95 which consisted of whole-prostate IMRT to 77Gy and a simultaneous integrated boost to the GTV-PET up to 95Gy (35 fractions). The feasibility of these plans was judged by their ability to adhere to the FLAME trial protocol. TCP-histo/-PET were calculated on co-registered histology (GTV-histo) and GTV-PET, respectively. NTCPs for rectum and bladder were calculated.ResultsAll plans reached prescription doses whilst adhering to dose constraints. In Plan77 and Plan95 mean doses in GTV-histo were 75.8±0.3Gy and 96.9±1Gy, respectively. Average TCP-histo values for Plan77 and Plan95 were 70% (range: 15–97%), and 96% (range: 78–100%, p77 and Plan95 were 55% (range: 27–82%), and 100% (range: 99–100%, p95 (p=0.25). There were no significant differences in rectal (p=0.563) and bladder (p=0.3) NTCPs.ConclusionsIMRT dose painting using PSMA PET/CT was technically feasible and resulted in significantly higher TCPs without higher NTCPs
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