1,335 research outputs found

    Avant-Propos

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    The deep conservation of the Lepidoptera Z chromosome suggests a non canonical origin of the W

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    Moths and butterflies (Lepidoptera) usually have a pair of differentiated WZ sex chromosomes. However, in most lineages outside of the division Ditrysia, as well as in the sister order Trichoptera, females lack a W chromosome. The W is therefore thought to have been acquired secondarily. Here we compare the genomes of three Lepidoptera species (one Dytrisia and two non-Dytrisia) to test three models accounting for the origin of the W: (1) a Z-autosome fusion; (2) a sex chromosome turnover; and (3) a non-canonical mechanism (e.g., through the recruitment of a B chromosome). We show that the gene content of the Z is highly conserved across Lepidoptera (rejecting a sex chromosome turnover) and that very few genes moved onto the Z in the common ancestor of the Ditrysia (arguing against a Z-autosome fusion). Our comparative genomics analysis therefore supports the secondary acquisition of the Lepidoptera W by a non-canonical mechanism, and it confirms the extreme stability of well-differentiated sex chromosomes

    Small-Angle CMB Temperature Anisotropies Induced by Cosmic Strings

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    We use Nambu-Goto numerical simulations to compute the cosmic microwave background (CMB) temperature anisotropies induced at arcminute angular scales by a network of cosmic strings in a Friedmann-Lemaitre-Robertson-Walker (FLRW) expanding universe. We generate 84 statistically independent maps on a 7.2 degree field of view, which we use to derive basic statistical estimators such as the one-point distribution and two-point correlation functions. At high multipoles, the mean angular power spectrum of string-induced CMB temperature anisotropies can be described by a power law slowly decaying as \ell^{-p}, with p=0.889 (+0.001,-0.090) (including only systematic errors). Such a behavior suggests that a nonvanishing string contribution to the overall CMB anisotropies may become the dominant source of fluctuations at small angular scales. We therefore discuss how well the temperature gradient magnitude operator can trace strings in the context of a typical arcminute diffraction-limited experiment. Including both the thermal and nonlinear kinetic Sunyaev-Zel'dovich effects, the Ostriker-Vishniac effect, and the currently favored adiabatic primary anisotropies, we find that, on such a map, strings should be ``eye visible,'' with at least of order ten distinctive string features observable on a 7.2 degree gradient map, for tensions U down to GU \simeq 2 x 10^{-7} (in Planck units). This suggests that, with upcoming experiments such as the Atacama Cosmology Telescope (ACT), optimal non-Gaussian, string-devoted statistical estimators applied to small-angle CMB temperature or gradient maps may put stringent constraints on a possible cosmic string contribution to the CMB anisotropies.Comment: 17 pages, 9 figures. v2: matches published version, minor clarifications added, typo in Eq. (8) fixed, results unchange

    Non-Parametric Analysis of ENSO Impacts on Yield Distributions: Implications for GRP Contract Design

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    The paper reports preliminary results of non-parametric analysis of historical and crop model generated peanut yield series in the Southwest Georgia. The results suggest ENSO phase dependent differences in yield distributions that are similar for both the simulated and actual series. The differences are magnified in GRP insurance premiums.Crop Production/Industries,

    Machine vision based system for flower counting in strawberry plants

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    Background: For strawberry production, accurate yield prediction is very important to help growers increase their profit by efficiently managing their harvesting operation and setting their contracts with buyers. Strawberry plants produce flowers and fruits simultaneously throughout the season. Strawberry flowers are white in color with a yellow pollen at the center, which later becomes a fruit. Strawberry yield can be estimated by counting the number of flowers in a field in advance of harvesting. The objective of this project is to count the number of flowers using image processing techniques, create a map of flower counts using gee-tagging and provide farmers with an estimate of the yield in a given area. Methods: Strawberry flowers could be at different stages of maturation during imaging. We pre-process images using edge-preserving smoothing filter to remove noise without removing fine features. The next stage involves segmentation of flowers from the background. Since flowers are brighter than most other components of plants, simple thresholding with segmentation algorithm will produce candidate pixels. Then flower detection will be conducted using traditional feature engineering along with a classifier such as Histogram of Oriented Gradients, Wavelet Transform, Local Binary Patterns, and the Deep Learning based techniques. Results: Once flowers are detected, the number of flowers is counted to provide farmers with an estimate of yield and variability at different locations in the field. Discussions: One of the biggest challenges with outdoor imaging is the variable lighting conditions. We propose a camera mounted autonomous system to go over rows of strawberry plants to capture images with geo-tags. Cameras are positioned to capture images from different angles to capture occluded flowers. Conclusion: A novel image processing method for accurate strawberry yield prediction is proposed by counting the number of flowers from images for efficient crop management

    Hereditary sensory and autonomic neuropathy type IV and orthopaedic complications

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    SummaryHereditary sensory and autonomic neuropathy type IV (HSAN-IV) is a very rare autosomal recessive disorder characterized by recurrent episodes of unexplained fever, extensive anhidrosis, total insensitivity to pain, hypotonia, and mental retardation. The most frequent complications of this disease are corneal scarring, multiple fractures, joint deformities, osteomyelitis, and disabling self-mutilations. We reported the case of a 12-year-old boy. The goal was to discuss our decision-making and compare this case with cases described in the literature
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