2,442 research outputs found

    Detection and Identification of Molecular Water Pollutants by Laser Raman Spectroscopy

    Get PDF
    Laser Raman spectroscopy is evolving into a primary tool for the Identification of molecular water pollutants. This study pushes the limits of detectivity of carbon disulfide and benzene to ~ 20 ppm in water solutions using a high-resolution Raman spectrometer, cooled detectors, and photon counting techniques. The primary limiting factors were found to be the low throughput and the scattered light performance of the monochromator as well as insufficient laser energy. An optomized design for a pollution-measuring instrument is suggested, and a prototype has been built which is useful with any value of excitation energy short of sample degrading. The present instrument scans spectrum windows with fixed preselecting filters followed by a small single monochromator with high throughput. No detector cooling or refinements in signal processing were attempted. The resulting detectivity with 20 mw of laser power was only 1000 ppm. However, the scattered light background or optical noise is unmeasurable except at the laser frequency, where it was a maximum of six percent of full scale measured against the 992 cm-1 Raman band of benzene. Equipped with an ion laser a practical field instrument capable of detectivity of 1 ppm will cost about 20,000.Theinstrumentdescribedhereincanbebuiltfor20,000. The instrument described herein can be built for 4,000, less laser

    Association of blood pressure with knee cartilage composition and structural knee abnormalities: data from the osteoarthritis initiative.

    Get PDF
    ObjectiveTo investigate the associations of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with changes in knee cartilage composition and joint structure over 48 months, using magnetic resonance imaging (MRI) data from the Osteoarthritis Initiative (OAI).Materials and methodsA total of 1126 participants with right knee Kellgren-Lawrence (KL) score 0-2 at baseline, no history of rheumatoid arthritis, blood pressure measurements at baseline, and cartilage T2 measurements at baseline and 48 months were selected from the OAI. Cartilage composition was assessed using MRI T2 measurements, including laminar and gray-level co-occurrence matrix texture analyses. Structural knee abnormalities were graded using the whole-organ magnetic resonance imaging score (WORMS). We performed linear regression, adjusting for age, sex, body mass index, physical activity, smoking status, alcohol use, KL score, number of anti-hypertensive medications, and number of nonsteroidal anti-inflammatory drugs.ResultsHigher baseline DBP was associated with greater increases in global T2 (coefficient 0.22 (95% CI 0.09, 0.34), P = 0.004), global superficial layer T2 (coefficient 0.39 (95% CI 0.20, 0.58), P = 0.001), global contrast (coefficient 15.67 (95% CI 8.81, 22.53), P < 0.001), global entropy (coefficient 0.02 (95% CI 0.01, 0.03) P = 0.011), and global variance (coefficient 9.14 (95% CI 5.18, 13.09), P < 0.001). Compared with DBP, the associations of SBP with change in cartilage T2 parameters and WORMS subscores showed estimates of smaller magnitude.ConclusionHigher baseline DBP was associated with higher and more heterogenous cartilage T2 values over 48 months, indicating increased cartilage matrix degenerative changes

    Associations between alcohol, smoking, and cartilage composition and knee joint morphology: Data from the Osteoarthritis Initiative

    Get PDF
    Summary: Objective: To determine the cross-sectional associations of alcohol consumption and smoking history with magnetic resonance imaging (MRI) measures of cartilage composition (T2) and joint structure using data from the Osteoarthritis Initiative (OAI). Design: Subjects with radiographic Kellgren Lawrence right knee grades 0–2 were selected from the OAI database, and those with previously analyzed MRI cartilage T2 and semi-quantitative joint morphology gradings (WORMS) were included (n ​= ​2061). Alcohol consumption was categorized as: no drinks to 7 drinks/week. Smoking history was categorized as none, current, or former. Linear regression was used to assess the relationships of alcohol consumption and smoking history with both WORMS scores and cartilage T2. Results: Subjects who consumed >7 drinks/week had significantly higher cartilage T2 than subjects who consumed 7 drinks/week was associated with elevated cartilage T2. Compared to non-smokers, current smokers had a more degenerated cartilage matrix as evidenced by greater cartilage T2

    Integrating LiDAR data and multi-temporal aerial imagery to map wetland inundation dynamics using Google Earth Engine

    Get PDF
    The Prairie Pothole Region of North America is characterized by millions of depressional wetlands, which provide critical habitats for globally significant populations of migratory waterfowl and other wildlife species. Due to their relatively small size and shallow depth, these wetlands are highly sensitive to climate variability and anthropogenic changes, exhibiting inter- and intra-annual inundation dynamics. Moderate-resolution satellite imagery (e.g., Landsat, Sentinel) alone cannot be used to effectively delineate these small depressional wetlands. By integrating fine spatial resolution Light Detection and Ranging (LiDAR) data and multi-temporal (2009–2017) aerial images, we developed a fully automated approach to delineate wetland inundation extent at watershed scales using Google Earth Engine. Machine learning algorithms were used to classify aerial imagery with additional spectral indices to extract potential wetland inundation areas, which were further refined using LiDAR-derived landform depressions. The wetland delineation results were then compared to the U.S. Fish and Wildlife Service National Wetlands Inventory (NWI) geospatial dataset and existing global-scale surface water products to evaluate the performance of the proposed method. We tested the workflow on 26 watersheds with a total area of 16,576 km2 in the Prairie Pothole Region. The results showed that the proposed method can not only delineate current wetland inundation status but also demonstrate wetland hydrological dynamics, such as wetland coalescence through fill-spill hydrological processes. Our automated algorithm provides a practical, reproducible, and scalable framework, which can be easily adapted to delineate wetland inundation dynamics at broad geographic scales

    Discovering compassion in medical training: a qualitative study with curriculum leaders, educators, and learners

    Get PDF
    BackgroundCompassion is considered a fundamental human capacity instrumental to the creation of medicine and for patient-centered practice and innovations in healthcare. However, instead of nurturing and cultivating institutional compassion, many healthcare providers cite the health system itself as a direct barrier to standard care. The trend of compassion depletion begins with medical students and is often attributed to the culture of undergraduate medical training, where students experience an increased risk of depression, substance use, and suicidality.ObjectivesThis qualitative study aims to develop a more comprehensive understanding of compassion as it relates to undergraduate medical education. We used focus groups with key stakeholders in medical education to characterize beliefs about the nature of compassion and to identify perceived barriers and facilitators to compassion within their daily responsibilities as educators and students.MethodsResearchers conducted a series of virtual (Zoom) focus groups with stakeholders: Students (N = 14), Small Group Advisors (N = 11), and Medical Curriculum Leaders (N = 4). Transcripts were thematically analyzed using MAXQDA software.ResultsStudy participants described compassion as being more than empathy, demanding action, and capable of being cultivated. Stakeholders identified self-care, life experiences, and role models as facilitators. The consistently identified barriers to compassion were time constraints, culture, and burnout. Both medical students and those training them agreed on a general definition of compassion and that there are ways to cultivate more of it in their daily professional lives. They also agreed that undergraduate medical education – and the healthcare culture at large – does not deliberately foster compassion and may be directly contributing to its degradation by the content and pedagogies emphasized, the high rates of burnout and futility, and the overwhelming time constraints.DiscussionIntentional instruction in and cultivation of compassion during undergraduate medical education could provide a critical first step for undergirding the professional culture of healthcare with more resilience and warm-hearted concern. Our finding that medical students and those training them agree about what compassion is and that there are specific and actionable ways to cultivate more of it in their professional lives highlights key changes that will promote a more compassionate training environment conducive to the experience and expression of compassion

    Training of Instrumentalists and Development of New Technologies on SOFIA

    Full text link
    This white paper is submitted to the Astronomy and Astrophysics 2010 Decadal Survey (Astro2010)1 Committee on the State of the Profession to emphasize the potential of the Stratospheric Observatory for Infrared Astronomy (SOFIA) to contribute to the training of instrumentalists and observers, and to related technology developments. This potential goes beyond the primary mission of SOFIA, which is to carry out unique, high priority astronomical research. SOFIA is a Boeing 747SP aircraft with a 2.5 meter telescope. It will enable astronomical observations anywhere, any time, and at most wavelengths between 0.3 microns and 1.6 mm not accessible from ground-based observatories. These attributes, accruing from the mobility and flight altitude of SOFIA, guarantee a wealth of scientific return. Its instrument teams (nine in the first generation) and guest investigators will do suborbital astronomy in a shirt-sleeve environment. The project will invest $10M per year in science instrument development over a lifetime of 20 years. This, frequent flight opportunities, and operation that enables rapid changes of science instruments and hands-on in-flight access to the instruments, assure a unique and extensive potential - both for training young instrumentalists and for encouraging and deploying nascent technologies. Novel instruments covering optical, infrared, and submillimeter bands can be developed for and tested on SOFIA by their developers (including apprentices) for their own observations and for those of guest observers, to validate technologies and maximize observational effectiveness.Comment: 10 pages, no figures, White Paper for Astro 2010 Survey Committee on State of the Professio

    Molecular diversity of anthracnose pathogen populations associated with UK strawberry production suggests multiple introductions of three different Colletotrichum species.

    Get PDF
    Fragaria Ă— ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production
    • …
    corecore