2,187 research outputs found

    Using VPS (VoxMap Pointshell) as the Basis for Interaction in a Virtual Assembly Environment

    Get PDF
    Realistic part interaction is an important component of an effective virtual assembly application. Both collision detection and part interaction modeling are needed to simulate part-topart and hand-to-part interactions. This paper presents a comparison of several common collision detection algorithms and examines the VoxMap Pointshell (VPS) method as it is used in an application to evaluate proposed assembly methods. Results from several performance tests on VPS are presented. VPS was found to provide realistic collisions and physicallybased modeling interaction with excellent performance. This paper concludes by presenting how VPS has been implemented to handle multiple dynamic part collisions and two-handed assembly using the 5DT dataglove in a projection screen virtual environment

    Microscopic Inner Retinal Hyper-reflective Phenotypes in Retinal and Neurologic Disease

    Get PDF
    Purpose. We surveyed inner retinal microscopic features in retinal and neurologic disease using a reflectance confocal adaptive optics scanning light ophthalmoscope (AOSLO). Methods. Inner retinal images from 101 subjects affected by one of 38 retinal or neurologic conditions and 11 subjects with no known eye disease were examined for the presence of hyper-reflective features other than vasculature, retinal nerve fiber layer, and foveal pit reflex. The hyper-reflective features in the AOSLO images were grouped based on size, location, and subjective texture. Clinical imaging, including optical coherence tomography (OCT), scanning laser ophthalmoscopy, and fundus photography was analyzed for comparison. Results. Seven categories of hyper-reflective inner retinal structures were identified, namely punctate reflectivity, nummular (disc-shaped) reflectivity, granular membrane, waxy membrane, vessel-associated membrane, microcysts, and striate reflectivity. Punctate and nummular reflectivity also was found commonly in normal volunteers, but the features in the remaining five categories were found only in subjects with retinal or neurologic disease. Some of the features were found to change substantially between follow up imaging months apart. Conclusions. Confocal reflectance AOSLO imaging revealed a diverse spectrum of normal and pathologic hyper-reflective inner and epiretinal features, some of which were previously unreported. Notably, these features were not disease-specific, suggesting that they might correspond to common mechanisms of degeneration or repair in pathologic states. Although prospective studies with larger and better characterized populations, along with imaging of more extensive retinal areas are needed, the hyper-reflective structures reported here could be used as disease biomarkers, provided their specificity is studied further

    Research students exhibition catalogue 2011

    Get PDF
    The catalogue demonstrates the scope and vibrancy of current inquiries and pays tribute to the creative capacity and investment of UCA research students. It brings together contributions from students who are at different stages in their research ad/venture. Their explorations are connected by the centrality of contemporary material practices as focal point for the reconsideration of societal values, cultural symbols and rituals and their meaning, and the trans/formation of individual, collective and national identities The media and formats employed range from cloth, jewellery and ceramics to analogue film, the human voice and the representation of dress and fashionin virtual environments. Thematic interests span from explorations at the interface of art and medical science to an investigation of the role of art in contested spaces, or the role of metonymy in ‘how the arts think’ And whilst the projects are motivated by personal curiosity and passion, their outcomes transcend the boundaries of individual practice and offer new insights, under-standing and applications for the benefit of wider society. Prof. Kerstin Me

    Probing folded and unfolded states of outer membrane protein a with steady-state and time-resolved tryptophan fluorescence

    Get PDF
    Steady-state and time-resolved fluorescence measurements on each of five native tryptophan residues in full-length and truncated variants of E. coli outer-membrane protein A (OmpA) have been made in folded and denatured states. Tryptophan singlet excited-state lifetimes are multiexponential and vary among the residues. In addition, substantial increases in excited-state lifetimes accompany OmpA folding, with longer lifetimes in micelles than in phospholipid bilayers. This finding suggests that the Trp environments of OmpA folded in micelles and phospholipid bilayers are different. Measurements of Trp fluorescence decay kinetics with full-length OmpA folded in brominated lipid vesicles reveal that W102 is the most distant fluorophore from the hydrocarbon core, while W7 is the closest. Steady-state and time-resolved polarized fluorescence measurements indicate reduced Trp mobility when OmpA is folded in a micelle, and even lower mobility when the protein is folded in a bilayer. The fluorescence properties of truncated OmpA, in which the soluble periplasmic domain is removed, only modestly differ from those of the full-length form, suggesting similar folded structures for the two forms under these conditions

    Phase I Study of Ipilimumab Combined with Whole Brain Radiation Therapy or Radiosurgery for Melanoma Patients with Brain Metastases

    Get PDF
    Purpose: We performed a phase I study to determine the maximum tolerable dose (MTD) and safety of ipilimumab with stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT) in patients with brain metastases (BM) from melanoma. Methods: Based on intracranial (IC) disease burden, patients were treated with WBRT (Arm A) or SRS (Arm B). Ipilimumab starting dose was 3 mg/kg (every 3 weeks, starting on day 3 of WBRT or 2 days after SRS). Ipilimumab was escalated to 10 mg/kg using a two-stage, 3+3 design. The primary endpoint was to determine the MTD of ipilimumab combined with radiotherapy. Secondary endpoints were overall survival (OS), IC and extracranial (EC) control, progression free survival (PFS), and toxicity. This trial is regis- tered with ClinicalTrials.gov, number NCT01703507. Results: Characteristics of the 16 patients enrolled between 2011 and 2014 were: mean age, 60; median BM, 2 (1 to \u3e10); number with EC disease, 13 (81%). Treatment included WBRT (n=5), SRS (n=11), ipilimumab 3mg/kg (n=7), 10 mg/kg (n=9). Median follow-up was 8 months (Arm A) and 10.5 months (Arm B). There were 21 grade 1-2 neuro- toxic effects with no dose-limiting toxicities (DLTs). One patient experienced grade 3 neurotoxicity prior to ipilimumab administration. Ten additional grade 3 toxicities were reported with gastrointestinal (n=5, 31%) as the most common. There were no grade 4/5 toxicities. Median PFS and OS, respectively, in Arm A were 2.5 months and 8 months, and in Arm B were 2.1 months and not reached. Conclusion: Concurrent ipilimumab 10 mg/kg with SRS is safe. The WBRT arm was closed early due to slow accrual, but demonstrated safety with ipilimumab 3 mg/kg. No patient experienced DLT. Larger studies with ipilimumab 10 mg/kg and SRS are warranted

    Salvage Fractionated Stereotactic Re-irradiation (FSRT) for Patients with Recurrent High Grade Gliomas Progressed after Bevacizumab Treatment

    Get PDF
    Purpose/Objectives: Bevacizumab failure is a major clinical problem in the manage- ment of high grade gliomas (HGG), with a median overall survival of less than 4 months (m). This study evaluated the efficacy of fractionated stereotactic re-irradiation (FSRT) for patients with HGG after progression on Bevacizumab. Materials/Methods: Retrospective review was conducted of patients treated with FSRT after progression on bevacizumab. A total of 36 patients were identified. FSRT was most commonly delivered in 3.5 Gy fractions to a total dose of 35 Gy. Survival from initial diagnosis, as well as from recurrence and re-irradiation, were utilized as study endpoints. Univariate and multivariate analysis was performed. Results: Among the 36 patients, 31 patients had recurrent glioblastoma, and 5 patients had recurrent anaplastic astrocytoma. The median time from initial bevacizumab treatment to FSRT was 8.5 m (range 2.3 – 32.0 m). The median plan target volume for FSRT was 27.5 cc (range 1.95 – 165 cc). With a median follow up of 20.4 m, the overall survival of the patients since initial diagnosis was also 24.9 m. The median overall survival after initiation of bevacizumab was 13.4 months. The median overall survival from FSRT was 4.8 m. FSRT treatment was well tolerated with no Grade \u3e3 toxicity. Conclusions: Favorable outcomes were observed in patients with recurrent HGG who received salvage FSRT after bevacizumab failure. The treatment was well tolerated. Prospective study is warranted to further evaluate the efficacy of salvage FSRT for selected patients with recurrent HGG amenable to FSRT, who had failed bevacizumab treatment

    Imprints, Vol. 2

    Get PDF
    Imprints is the official publication for Sigma Tau Delta, the honorary English fraternity. The editors welcome creative works submitted by contributors and also publish winners of the annual T. E. Ferguson Writing Contest. Especially welcome are poems, fiction pieces and essays of no more than 5,000 words in length. At this time we would like to express our gratitude to David Whitescarver, Sigma Tau Delta faculty advisor, for his unrelenting optimism and valuable help in the preparation of this journal

    Statistical Characterization of the Chandra Source Catalog

    Full text link
    The first release of the Chandra Source Catalog (CSC) contains ~95,000 X-ray sources in a total area of ~0.75% of the entire sky, using data from ~3,900 separate ACIS observations of a multitude of different types of X-ray sources. In order to maximize the scientific benefit of such a large, heterogeneous data-set, careful characterization of the statistical properties of the catalog, i.e., completeness, sensitivity, false source rate, and accuracy of source properties, is required. Characterization efforts of other, large Chandra catalogs, such as the ChaMP Point Source Catalog (Kim et al. 2007) or the 2 Mega-second Deep Field Surveys (Alexander et al. 2003), while informative, cannot serve this purpose, since the CSC analysis procedures are significantly different and the range of allowable data is much less restrictive. We describe here the characterization process for the CSC. This process includes both a comparison of real CSC results with those of other, deeper Chandra catalogs of the same targets and extensive simulations of blank-sky and point source populations.Comment: To be published in the Astrophysical Journal Supplement Series (Fig. 52 replaced with a version which astro-ph can convert to PDF without issues.

    Application of immunocytochemistry and BRAF mutational analysis to direct smears of metastatic melanoma

    Full text link
    BACKGROUND: The cytodiagnosis of melanoma in fine‐needle aspiration (FNA) specimens can be challenging, often requiring the use of immunocytochemistry. As constitutively activating mutations in the BRAF oncogene are present in at least 40% of melanomas, the use of FNA material to interrogate the BRAF mutational status is likely to increase. Because cell blocks, traditionally used for these studies, can occasionally exhibit insufficient tumor cellularity, the authors investigated the utility of direct smears for immunocytochemistry and BRAF mutational analysis. METHODS: Immunocytochemistry for S‐100, HMB‐45, and Mart‐1 was prospectively performed on direct smears in 17 FNAs of metastatic melanoma. Next, BRAF sequencing was performed using DNA isolated from archived Diff‐Quik–stained direct smears for 15 cases. In parallel, sequencing was performed using DNA obtained from corresponding cell blocks. RESULTS: S‐100 positivity in the tumor cells was observed in all 17 cases. HMB‐45 and Mart‐1 positivity was noted in 81% and 88% of cases, respectively. All 3 markers were positive in 76% of cases. Next, of the 15 archived melanoma FNAs tested, BRAF mutations were observed in 8 (53%); 5 and 3 melanomas harbored the V600E and V600K mutation, respectively. Corresponding cell blocks were also tested for all 15 cases, yielding concordant BRAF results in 14 (93%); 1 cell block yielded a false‐negative result. CONCLUSIONS: Cytologic direct smears represent a robust and valuable source of cellular material for immunocytochemistry and molecular studies, especially in instances in which inadequate cell block cellularity is anticipated or encountered. Cancer (Cancer Cytopathol) 2012. © 2011 American Cancer Society. This study demonstrates that direct smears represent a robust and valuable source of cellular material for ancillary studies used in the cytologic diagnosis of melanoma. Direct smears can be effectively used for confirmatory immunocytochemical studies and molecular assays designed to interrogate the BRAF mutational status of melanoma, especially in scenarios in which inadequate cell block cellularity is anticipated or encountered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90193/1/20180_ftp.pd

    Combining Dynamic Modeling With Geometric Constraint Management to Support Low Clearance Virtual Manual Assembly

    Get PDF
    This research presents a novel approach to virtual assembly that combines dynamic modeling with geometric constraint-based modeling to support low clearance manual assembly of CAD models. This is made possible by utilizing the boundary representation solid model data available in most contemporary CAD representations, which enables (a) accurate collision/physics calculations on exact model definitions, and (b) access to geometric features. Application of geometric constraints during run-time, aid the designer during assembly of the virtual models. The feasibility of the approach is demonstrated using a pin and hole assembly example. Results that demonstrate the method give the user the ability to assemble parts without requiring extensive CAD preprocessing and without over constraining the user to arrive at predetermined final part orientations. Assembly is successful with diametral clearance as low as 0.0001 mm, as measured between a 26 mm diameter hole and pin
    corecore