335 research outputs found

    Foragebeef.ca Web Site: A Model for Technology Transfer

    Get PDF
    We live in an age of information overload. As budgets for technology transfer of scientific information and extension education continue to fall, new ways to disseminate agricultural knowledge are needed. Research findings, published in many scientific journals and reports, are seldom readily available to extension agents and farmers. Over time some of this material is lost. This program aimed to locate the best information on various forage and beef topics relative to Canada and the Northern USA and to summarise them in condensed form and in scientific review papers for a web-based site

    Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries

    Get PDF
    Few observational constraints exist for the tidal synchronization rate of late-type stars, despite its fundamental role in binary evolution. We visually inspected the light curves of 2278 eclipsing binaries (EBs) from the Kepler Eclipsing Binary Catalog to identify those with starspot modulations, as well as other types of out-of-eclipse variability. We report rotation periods for 816 EBs with starspot modulations, and find that 79% of EBs with orbital periods less than ten days are synchronized. However, a population of short period EBs exists with rotation periods typically 13% slower than synchronous, which we attribute to the differential rotation of high latitude starspots. At 10 days, there is a transition from predominantly circular, synchronized EBs to predominantly eccentric, pseudosynchronized EBs. This transition period is in good agreement with the predicted and observed circularization period for Milky Way field binaries. At orbital periods greater than about 30 days, the amount of tidal synchronization decreases. We also report 12 previously unidentified candidate δ\delta Scuti and γ\gamma Doradus pulsators, as well as a candidate RS CVn system with an evolved primary that exhibits starspot occultations. For short period contact binaries, we observe a period-color relation, and compare it to previous studies. As a whole, these results represent the largest homogeneous study of tidal synchronization of late-type stars.Comment: Accepted for publication in the Astronomical Journal. EB rotation periods and classifications available at https://github.com/jlurie/decatur/blob/master/decatur/data/final_catalog.cs

    A Gyrochronology and Microvariability Survey of the Milky Way's Older Stars Using Kepler's Two-Wheels Program

    Full text link
    Even with the diminished precision possible with only two reaction wheels, the Kepler spacecraft can obtain mmag level, time-resolved photometry of tens of thousands of sources. The presence of such a rich, large data set could be transformative for stellar astronomy. In this white paper, we discuss how rotation periods for a large ensemble of single and binary main- sequence dwarfs can yield a quantitative understanding of the evolution of stellar spin-down over time. This will allow us to calibrate rotation-based ages beyond ~1 Gyr, which is the oldest benchmark that exists today apart from the Sun. Measurement of rotation periods of M dwarfs past the fully-convective boundary will enable extension of gyrochronology to the end of the stellar main-sequence, yielding precise ages ({\sigma} ~10%) for the vast majority of nearby stars. It will also help set constraints on the angular momentum evolution and magnetic field generation in these stars. Our Kepler-based study would be supported by a suite of ongoing and future ground-based observations. Finally, we briefly discuss two ancillary science cases, detection of long-period low-mass eclipsing binaries and microvariability in white dwarfs and hot subdwarf B stars that the Kepler Two-Wheels Program would facilitate.Comment: Kepler white pape

    Plan, execute, and discuss vibration measurements and correlations to evaluate a NASTRAN finite element model of the AH-64 helicopter airframe

    Get PDF
    A ground vibration test was performed on the AH-64 (Apache) helicopter to determine the frequency response of the airframe. The structure was excited at both the main and tail rotor hubs, separately, and response measurements were taken at 102 locations throughout the fuselage structure. Frequency responses were compared and correlated with results from a NASTRAN finite element model of AH-64. In addition, natural frequencies and mode shapes were estimated from the frequency response data and were correlated with analytical results

    Long-Term Outcomes of Autologous Stem Cell Transplantation for Follicular Non-Hodgkin Lymphoma: Effect of Histological Grade and Follicular International Prognostic Index

    Get PDF
    AbstractAlthough results of autologous stem cell transplantation (SCT) for recurrent follicular non-Hodgkin lymphoma (NHL) have been previously reported, the long-term results and evaluation of prognostic factors in a large patient population receiving this therapy are difficult to find in the literature. To address these issues, we evaluated 248 patients with recurrent follicular NHL treated with high-dose chemotherapy and autologous SCT between 7/87 and 6/03. According to the World Health Organization (WHO) classification system, 64 patients (26%) had follicular NHL grade 1 (FL 1), 98 (40%) had FL 2, and 86 (35%) had FL 3. At the time of transplantation, 88 of the patients (35%) had a Follicular Lymphoma International Prognostic Index (FLIPI) score of low risk, 87 (35%) had an intermediate-risk FLIPI score, 37 (15%) had a high-risk FLIPI score, and 36 (15%) had at least 1 missing value, preventing calculation of the FLIPI score. The 5-year overall survival (OS) for all patients was 63%, and the 5-year progression-free survival (PFS) was 44%. In a multivariate analysis, a histological grade of FL 3, a high-risk FLIPI score at the time of transplantation, and having received 3 or more previous chemotherapy regimens were significant factors for predicting a worse OS. In addition, the use of a transplantation regimen including a monoclonal antibody decreased the relative risk of progressive lymphoma. These data suggest that transplantation earlier in the course of the disease for patients with follicular lymphoma with use of a monoclonal antibody–based regimen may lead to improved outcomes

    Einfluss der Umnutzung eines 20-jährigen Miscanthusbestands auf die Humusgehalte und -qualität einer Parabraunerde

    Get PDF
    In einem Feldversuch nahe Freiburg soll der Einfluss einer ackerbaulichen Nutzung nach Miscanthusumbruch auf die Humusgehalte und –qualität einer Parabraunerde untersucht werden. In einem ersten Schritt wurden die Corg-Gehalte einer 20-jährigen Miscanthusfläche räumlich hoch aufgelöst bis 60 cm Tiefe untersucht und mit den Corg-Gehalten einer angrenzenden Ackerfläche verglichen. Mit 75,6 t C ha-1 wurden auf der Miscanthusfläche um 20 Tonnen höhere Corg-Gehalte gemessen als auf der benachbarten Ackerfläche. Dies entspricht somit einer jährlichen Zunahme der Corg-Gehalte von 1 t a-1. Die größte C-Zunahme wurde dabei in den obersten 10 Zentimeters des Bodens ermittelt. In einem Brutversuch mit Oberboden der beiden Versuchsflächen (25°C, 34 Tage) wurden bei Miscanthus 4,3% des organischen C als CO2 freigesetzt. Im Ackerboden waren dies lediglich 2,3% des organischen C. Das deutet auf einen höheren Anteil an labilem C bei Miscanthus hin und wurde durch einen ca. 3-fach höheren Anteil an heißwasserlöslichem C des Miscanthusbodens gegenüber dem Ackerboden bestätigt. 12C/13C-Isotopenmessungen ergaben zudem, dass das im Brutversuch freigesetzte CO2 nahezu vollständig Miscanthus-bürtig war. Auf dem Miscanthusfeld wurde 2015 ein Parzellenversuch etabliert. Auf vier Parzellen wird Miscanthus weiterhin genutzt, auf weiteren vier Parzellen wurde der Miscanthus im Frühjahr 2015 umgebrochen und eine Kleegrasmischung eingesät. Während sich die Corg-Gehalte der Miscanthusparzellen zwischen Frühjahr 2015 und Frühjahr 2016 nicht veränderten, wurde in der Umbruchvariante eine Abnahme der Corg-Gehalte um 2,8 t ha-1 ermittelt
    • …
    corecore