34,097 research outputs found

    New looks at and for Onespa, Buzyges, and Librita (Lepidoptera: Hesperiidae: Hesperiinae), with new combinations and descriptions of a new genus and six new species

    Get PDF
    Thirteen species of skippers (six newly described; Lepidoptera: Hesperiidae: Hesperiinae: Hesperiini) from higher elevations of Mexico and Central America are reviewed. These are included in four genera (one newly described), some with proposed new combinations. Onespa Steinhauser, 1974, originally described as monotypic, is shown to include three species in addition to its type species, Onespa nubis Steinhauser, 1974. One of these, Atrytone gala Godman, 1900, that has been misplaced in several genera since its description, represents a new combination. The other two species, distributed in montane habitats in northwestern Mexico and in Costa Rica, are described as new. Buzyges Godman, 1900, distributed in Mexico and Central America and also formerly considered monotypic, is shown to embrace four species. Besides the type species, Buzyges idothea Godman, 1900, two species long placed in Poanes Scudder, 1872, Pamphila rolla Mabille, 1883, and Poanes benito Freeman, 1979, are included as new combinations. Another species, known only from Costa Rica, is described as new. These are united by several superficial characters, but especially by genital morphology of both sexes. Librita Evans, 1955, was described to include three species of which one, Librita raspa Evans, 1955, was subsequently removed. Augiades heras Godman, 1900 is here also removed from Librita and placed in a new genus with three previously undescribed species. This completes the disintegration of Librita, which is now monotypic. The four genera, although exhibiting similarities suggesting potential alliance, differ in their unique combinations of several superficial and genital traits from each other and other hesperiine skippers

    Increased Lower Limb Spasticity but Not Strength or Function Following a Single-Dose Serotonin Reuptake Inhibitor in Chronic Stroke

    Get PDF
    Objective: To investigate the effects of single doses of a selective serotonin reuptake inhibitor (SSRI) on lower limb voluntary and reflex function in individuals with chronic stroke. Design: Double-blind, randomized, placebo-controlled crossover trial. Setting: Outpatient research setting. Participants: Individuals (N=10; 7 men; mean age ± SD, 57±10y) with poststroke hemiplegia of \u3e1 year duration who completed all assessments. Interventions: Patients were assessed before and 5 hours after single-dose, overencapsulated 10-mg doses of escitalopram (SSRI) or placebo, with 1 week between conditions. Main Outcome Measures: Primary assessments included maximal ankle and knee isometric strength, and velocity-dependent (30°/s–120°/s) plantarflexor stretch reflexes under passive conditions, and separately during and after 3 superimposed maximal volitional drive to simulate conditions of increased serotonin release. Secondary measures included clinical measures of lower limb coordination and locomotion. Results: SSRI administration significantly increased stretch reflex torques at higher stretch velocities (eg, 90°/s; P=.03), with reflexes at lower velocities enhanced by superimposed voluntary drive (P=.02). No significant improvements were seen in volitional peak torques or in clinical measures of lower limb function (lowest P=.10). Conclusions: Increases in spasticity but not strength or lower limb function were observed with single-dose SSRI administration in individuals with chronic stroke. Further studies should evaluate whether repeated dosing of SSRIs, or as combined with specific interventions, is required to elicit significant benefit of these agents on lower limb function poststroke

    A Comprehensive Method of Estimating Electric Fields from Vector Magnetic Field and Doppler Measurements

    Full text link
    Photospheric electric fields, estimated from sequences of vector magnetic field and Doppler measurements, can be used to estimate the flux of magnetic energy (the Poynting flux) into the corona and as time-dependent boundary conditions for dynamic models of the coronal magnetic field. We have modified and extended an existing method to estimate photospheric electric fields that combines a poloidal-toroidal (PTD) decomposition of the evolving magnetic field vector with Doppler and horizontal plasma velocities. Our current, more comprehensive method, which we dub the "{\bf P}TD-{\bf D}oppler-{\bf F}LCT {\bf I}deal" (PDFI) technique, can now incorporate Doppler velocities from non-normal viewing angles. It uses the \texttt{FISHPACK} software package to solve several two-dimensional Poisson equations, a faster and more robust approach than our previous implementations. Here, we describe systematic, quantitative tests of the accuracy and robustness of the PDFI technique using synthetic data from anelastic MHD (\texttt{ANMHD}) simulations, which have been used in similar tests in the past. We find that the PDFI method has less than 11% error in the total Poynting flux and a 1010% error in the helicity flux rate at a normal viewing angle (θ=0(\theta=0) and less than 2525% and 1010% errors respectively at large viewing angles (θ<60\theta<60^\circ). We compare our results with other inversion methods at zero viewing angle, and find that our method's estimates of the fluxes of magnetic energy and helicity are comparable to or more accurate than other methods. We also discuss the limitations of the PDFI method and its uncertainties.Comment: 56 pages, 10 figures, ApJ (in press

    Perception of Lower Extremity Loads in Stroke Survivors

    Get PDF
    Objective: This study aimed to improve our understanding of static and dynamic lower extremity sensory perception and the impact of sensory impairments on the control of walking in stroke survivors. Methods: Using a custom, real-time unloading system, we tested load perception at heel strike, mid stance and push off in 10 stroke survivors and compared their performance to 10 age-matched and 5 young adult control subjects. Dynamic load perception was based on a judgment of which leg was bearing more load, which was altered on a step by step basis. We also examined lower extremity static load perception, coordination, proprioception, balance, and gait symmetry. Results: The stroke survivors performed significantly worse than the control subjects in dynamic load perception, coordination, proprioception, balance and gait symmetry. Gait symmetry correlated with static and dynamic load perception measures but not with age, proprioception, coordination, and balance. Conclusions: Sensory deficits related to load detection in the impaired limb could result in an increased uncertainty of limb load and a gait strategy in which stroke survivors minimize loading of the impaired limb. Significance: This new method of measuring lower extremity dynamic load perception provides a framework for understanding gait-related sensory impairments in stroke survivors

    \u3ci\u3eAcrobasis\u3c/i\u3e Shoot Moth (Lepidoptera: Pyralidae) Infestation-Tree Height Link in a Young Black Walnut Plantation

    Get PDF
    Acrobasis shoot moth infestations were evaluated in a young black walnut progeny test for 4 years, from ages 3 to 6. Infestation levels were greatest on the largest trees in the fourth and fifth year after plantation establishment, and were declining by the sixth year. Acrobasis infestation appears to be a problem primarily on young trees less than 2.5 m in height. There was no evidence for genetic resistance to Acrobasis infestation in black walnut

    Effects of the pathogenesis of arbovirus infections in cattle on the efficiencies of vectors

    Get PDF

    Photospheric Electric Fields and Energy Fluxes in the Eruptive Active Region NOAA 11158

    Full text link
    How much electromagnetic energy crosses the photosphere in evolving solar active regions? With the advent of high-cadence vector magnetic field observations, addressing this fundamental question has become tractable. In this paper, we apply the "PTD-Doppler-FLCT-Ideal" (PDFI) electric field inversion technique of Kazachenko et al. (2014) to a 6-day HMI/SDO vector magnetogram and Doppler velocity sequence, to find the electric field and Poynting flux evolution in active region NOAA 11158, which produced an X2.2 flare early on 2011 February 15. We find photospheric electric fields ranging up to 22 V/cm. The Poynting fluxes range from [0.6[-0.6 to 2.3]×10102.3]\times10^{10} ergs\cdotcm2^{-2}s1^{-1}, mostly positive, with the largest contribution to the energy budget in the range of [109[10^9-1010]10^{10}] ergs\cdotcm2^{-2}s1^{-1}. Integrating the instantaneous energy flux over space and time, we find that the total magnetic energy accumulated above the photosphere from the initial emergence to the moment before the X2.2 flare to be E=10.6×1032E=10.6\times10^{32} ergs, which is partitioned as 2.02.0 and 8.6×10328.6\times10^{32} ergs, respectively, between free and potential energies. Those estimates are consistent with estimates from preflare non-linear force-free field (NLFFF) extrapolations and the Minimum Current Corona estimates (MCC), in spite of our very different approach. This study of photospheric electric fields demonstrates the potential of the PDFI approach for estimating Poynting fluxes and opens the door to more quantitative studies of the solar photosphere and more realistic data-driven simulations of coronal magnetic field evolution.Comment: 51 pages, 10 figures, accepted by ApJ on August 11, 201
    corecore