788 research outputs found

    Discrimination of Individual Tigers (\u3cem\u3ePanthera tigris\u3c/em\u3e) from Long Distance Roars

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    This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha\u27s Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, represented by the number of sequential states in the HMM. Results indicate that the temporal pattern of the vocalization is the most significant factor in accurate discrimination. Overall baseline discrimination accuracy for this data set is about 70% using high level features without complex spectral or temporal models. Accuracy increases to about 80% when more complex spectral models (multiple mixture GMMs) are incorporated, and increases to a final accuracy of 90% when more detailed temporal models (10-state HMMs) are used. Classification accuracy is stable across a relatively wide range of configurations in terms of spectral and temporal model resolution

    Mitigating the risk of Zika virus contamination of raw materials and cell lines in the manufacture of biologicals

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    Ensuring the virological safety of biologicals is challenging due to the risk of viral contamination of raw materials and cell banks, and exposure during in-process handling to known and/or emerging viral pathogens. Viruses may contaminate raw materials and biologicals intended for human or veterinary use and remain undetected until appropriate testing measures are employed. The outbreak and expansive spread of the mosquito-borne flavivirus Zika virus (ZIKV) poses challenges to screening human- and animal -derived products used in the manufacture of biologicals. Here, we report the results of an in vitro study where detector cell lines were challenged with African and Asian lineages of ZIKV. We demonstrate that this pathogen is robustly detectable by in vitro assay, thereby providing assurance of detection of ZIKV, and in turn underpinning the robustness of in vitro virology assays in safety testing of biologicals

    Pyrrole Syntheses Based on Titanium-Catalyzed Hydroamination of Diynes

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    Titanium-catalyzed hydroamination of 1,4- and 1,5-diynes by primary amines leads to imino-alkynes that undergo in situ 5-endo dig and 5-exo dig cyclization reactions, respectively. The products are 1,2,5-trisubstituted pyrroles accessed directly from readily available diyne starting materials

    Pyrrole Syntheses Based on Titanium-Catalyzed Hydroamination of Diynes

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    Titanium-catalyzed hydroamination of 1,4- and 1,5-diynes by primary amines leads to imino-alkynes that undergo in situ 5-endo dig and 5-exo dig cyclization reactions, respectively. The products are 1,2,5-trisubstituted pyrroles accessed directly from readily available diyne starting materials

    Colon polyps in patients with short bowel syndrome before and after teduglutide: post hoc analysis of the STEPS study series

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    Background & aims: Teduglutide promotes intestinal growth and is approved for the treatment of short bowel syndrome and intestinal failure (SBS-IF). Based on the pharmacologic activity and preclinical findings, teduglutide can potentially induce proliferative colonic mucosal changes. The aim of this study is to report the occurrence of colorectal polyps in adult patients with SBS-IF who received teduglutide in clinical studies conducted to date. Methods: A post hoc analysis of the completed Study of Teduglutide Effectiveness in Parenteral Nutrition-Dependent Short Bowel Syndrome Subjects (STEPS) clinical study series (NCT00798967, EudraCT 2008-006193-15; NCT00930644, EudraCT 2009-011679-65; NCT01560403) evaluated electronic case report form data for baseline colonoscopies (performed before treatment) and for surveillance or end-of-study (performed after treatment with teduglutide 0.05 mg/kg/day for 24 and 36 months) post-exposure procedures. Results: In the STEPS studies, 73 patients treated with teduglutide had a baseline colonoscopy. No post-exposure colonoscopy was scheduled in STEPS. In STEPS-2/3, 50 of 65 patients with remnant colon (77%) underwent a protocol-mandated post-exposure colonoscopy. Colon polyps were reported at baseline in 12% (9/73) of patients and post-exposure in 18% (9/50) of patients. Two had polyps both at baseline and post-exposure. On histology, available for 7 patients, 5 had adenomas (1 serrated, 4 tubular) and none had malignancy or high-grade dysplasia. Conclusion: These data support recommendations for colonoscopic screening before teduglutide therapy and subsequent on-therapy colonoscopic surveillance for patients with SBS-IF. Further studies are required to assess the risk of polyp formation in patients with SBS-IF and the most appropriate colon polyp surveillance strategies

    Characterization of wetting using topological principles

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    Hypothesis Understanding wetting behavior is of great importance for natural systems and technological applications. The traditional concept of contact angle, a purely geometrical measure related to curvature, is often used for characterizing the wetting state of a system. It can be determined from Young's equation by applying equilibrium thermodynamics. However, whether contact angle is a representative measure of wetting for systems with significant complexity is unclear. Herein, we hypothesize that topological principles based on the Gauss-Bonnet theorem could yield a robust measure to characterize wetting. Theory and Experiments We introduce a macroscopic contact angle based on the deficit curvature of the fluid interfaces that are imposed by contacts with other immiscible phases. We perform sessile droplet simulations followed by multiphase experiments for porous sintered glass and Bentheimer sandstone to assess the sensitivity and robustness of the topological approach and compare the results to other traditional approaches. Findings We show that the presented topological principle is consistent with thermodynamics under the simplest conditions through a variational analysis. Furthermore, we elucidate that at sufficiently high image resolution the proposed topological approach and local contact angle measurements are comparable. While at lower resolutions, the proposed approach provides more accurate results being robust to resolution-based effects. Overall, the presented concepts open new pathways to characterize the wetting state of complex systems and theoretical developments to study multiphase systems.Comment: 11 pages, 9 figures, 1 tabl

    A Mobile App For Delirium Screening

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    Objective: The objective of this study is to describe the algorithm and technical implementation of a mobile app that uses adaptive testing to assess an efficient mobile app for the diagnosis of delirium. Materials and Methods: The app was used as part of a NIH-funded project to assess the feasibility, effectiveness, administration time, and costs of the 2-step delirium identification protocol when performed by physicians and nurses, and certified nursing assistants (CNA). The cohort included 535 hospitalized patients aged 79.7 (SD¼6.6) years enrolled at 2 different sites. Each patient was assessed on 2 consecutive days by the research associate who performed the reference delirium assessment. Thereafter, physicians, nurses, and CNAs performed adaptive delirium assessments using the app. Qualitative data to assess the experience of administering the 2-step protocol, and the app usability were also collected and analyzed from 50 physicians, 189 nurses, and 83 CNAs. We used extensible hypertext markup language (XHTML) and JavaScript to develop the app for the iOS–based iPad. The App was linked to Research Electronic Data Capture (REDCap), a relational database system, via a REDCap application programming interface (API) that sent and received data from/to the app. The data from REDCap were sent to the Statistical Analysis System for statistical analysis. Results: The app graphical interface was successfully implemented by XHTML and JavaScript. The API facilitated the instant updating and retrieval of delirium status data between REDCap and the app. Clinicians performed 881 delirium assessments using the app for 535 patients. The transmission of data between the app and the REDCap system showed no errors. Qualitative data indicated that the users were enthusiastic about using the app with no negative comments, 82% positive comments, and 18% suggestions of improvement. Delirium administration time for the 2-step protocol showed similar total time between nurses and physicians (103.9 vs 106.5 seconds). Weekly enrollment reports of the app data were generated for study tracking purposes, and the data are being used for statistical analyses for publications. Discussion: The app developed using iOS could be easily converted to other operating systems such as Android and could be linked to other relational databases beside REDCap, such as electronic health records to facilitate better data retrieval and updating of patient’s delirium status
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