6 research outputs found
Dimensionality of genomic information and performance of the Algorithm for Proven and Young for different livestock species
International audienceAbstractBackgroundA genomic relationship matrix (GRM) can be inverted efficiently with the Algorithm for Proven and Young (APY) through recursion on a small number of core animals. The number of core animals is theoretically linked to effective population size (Ne). In a simulation study, the optimal number of core animals was equal to the number of largest eigenvalues of GRM that explained 98% of its variation. The purpose of this study was to find the optimal number of core animals and estimate Ne for different species.MethodsDatasets included phenotypes, pedigrees, and genotypes for populations of Holstein, Jersey, and Angus cattle, pigs, and broiler chickens. The number of genotyped animals varied from 15,000 for broiler chickens to 77,000 for Holsteins, and the number of single-nucleotide polymorphisms used for genomic prediction varied from 37,000 to 61,000. Eigenvalue decomposition of the GRM for each population determined numbers of largest eigenvalues corresponding to 90, 95, 98, and 99% of variation.ResultsThe number of eigenvalues corresponding to 90% (98%) of variation was 4527 (14,026) for Holstein, 3325 (11,500) for Jersey, 3654 (10,605) for Angus, 1239 (4103) for pig, and 1655 (4171) for broiler chicken. Each trait in each species was analyzed using the APY inverse of the GRM with randomly selected core animals, and their number was equal to the number of largest eigenvalues. Realized accuracies peaked with the number of core animals corresponding to 98% of variation for Holstein and Jersey and closer to 99% for other breed/species. Ne was estimated based on comparisons of eigenvalue decomposition in a simulation study. Assuming a genome length of 30 Morgan, Ne was equal to 149 for Holsteins, 101 for Jerseys, 113 for Angus, 32 for pigs, and 44 for broilers.ConclusionsEigenvalue profiles of GRM for common species are similar to those in simulation studies although they are affected by number of genotyped animals and genotyping quality. For all investigated species, the APY required less than 15,000 core animals. Realized accuracies were equal or greater with the APY inverse than with regular inversion. Eigenvalue analysis of GRM can provide a realistic estimate of Ne
Collaboration between Civilian and Military Healthcare Professionals: A Better Way for Planning, Preparing, and Responding to All Hazard Domestic Events
Collaboration is used by the US National Security Council as a means to integrate inter-federal government agencies during planning and execution of common goals towards unified, national security. The concept of collaboration has benefits in the healthcare system by building trust, sharing resources, and reducing costs. The current terrorist threats have made collaborative medical training between military and civilian agencies crucial. This review summarizes the long and rich history of collaboration between civilians and the military in various countries and provides support for the continuation and improvement of collaborative efforts. Through collaboration, advances in the treatment of injuries have been realized, deaths have been reduced, and significant strides in the betterment of the Emergency Medical System have been achieved. This review promotes collaborative medical training between military and civilian medical professionals and provides recommendations for the future based on medical collaboration
Low-Frequency Wave Activity Detected by MMS during Dusk Magnetopause Crossings and its Relation to Heating and Acceleration of Particles
International audienceSince the 9th of July, the MMS fleet of four satellites have evolved into a tetrahedral configuration with an average inter-satellite distance of 160 km and an apogee of 12 earth radii on the dusk side. In this study we report on ultra-low (1 mHz to ~10 Hz) and very-low (10 Hz to ~ 4 kHz) frequency wave activity measured by the four satellites during several crossings of the dusk equatorial magnetopause. Since the Larmor radius of magnetosheath protons is of the order of 50 km, this inter-satellite distance allows us to investigate in detail the physics of the magnetopause at proton scales including current structures related to Kelvin-Helmholtz instability as well as other energy transfer processes. From wave polarization analysis, we characterize the different types of emissions and discuss different mechanisms of heating and acceleration of particles. In particular, we focus on the electron heating by kinetic Alfvén waves and lower hybrid waves and the electron acceleration by oblique whistler mode waves, which have been suggested as possible mechanisms from previous Cluster and THEMIS measurements
First MMS measurements of the High Frequency Magnetic Waves
International audienceThe MMS mission was successfully launched on March 13, 2015 into an equatorial, highly elliptical orbit with a low altitude perigee and an apogee of 12 earth radii. Each satellite is equipped by a search-coil magnetometer (SCM) which measures the three components of the magnetic field fluctuations with a nominal frequency range from 1 Hz to 6 kHz. During the past months of the commissioning phase, the SCM waveforms have usually been gathered at 128 or 256 samples per second (S/s). Yet in a few cases, burst data corresponding to 8192 S/s were obtained. Since the launch, the orbit apogee has moved from dawn to dusk. These various conditions allow us to present high frequency wave measurements and wave polarization analysis in the dawn magnetosphere flank as well as associated with local and global dipolarization events in the night side. Furthermore, the SCM is not saturated due to a large amplitude spin modulation even at perigee since the MMS spin frequency is low (50 mHz). Thanks to the onboard spectra computed by the digital signal processor, we are able to continuously monitor the magnetic wave activity through the full SCM frequency range all along the orbit and notably in the radiation belt region. Thus some typical figures of the wave activity in the inner magnetosphere are also briefly described