530 research outputs found

    Relationship between visual field loss and maximal combined electroretinographic responses in retinitis pigmentosa : comparison among genetically different types

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    1984年から1996年までに千葉大学眼科を受診した定型網膜色素変性症228例について常優26例, 常劣64例, 孤発例138例に分け動的量的視野および網膜電図を検討した。Goldmann視野におけるV-4イソプターでは5から10cm^2までと150から250cm^2までの2群に別れ, 1-4イソプターでは5cm^2以下の群のみ認められた。加齢及び遺伝形式による差異は認められなかった。網膜電図ではa, b波ともに正常対照群より減少してはいるものの, 遺伝形式による差異は認められなかった。また, 網膜電図で振幅を認められる割合はV-4イソプターおよびI-4イソプターの面積と相関していることが示唆されたが, 遺伝形式による差異は認められなかった。網膜電図の振幅の比であるb/a比は正常対象群に対して疾患群は減少していたが, 常備は特に他に比べ有意に減少していた。定型網膜色素変性症の網膜電図や視野の検討は数多くなされてきたが, b/a比について統計的考察がなされてきたことはない。a波およびb波は組織学的に発生起源が異なっており, b波はa波のインパルスによって二次的に引き起こされることは以前より知られてきている。網膜電図において常備のb/a比が有意な低下を示すことは, 網膜障害の機序が他と異なる可能性が示唆された。Analyses were performed on 228 Japanese patients with retinitis pigmentosa (RP) who were classified with autosomal dominant (ADRP, n=26), autosomal recessive (ARRP, n=64), and simplex (simplex RP, rc=138) inheritance. Visual fields were tested with Goldmann perimetry. Maximal combined responses of electroretinogram (ERG) with 20-Joule white flash stimulation were recorded after dark adaptation for 20 minutes. The visual field with the V-4 isopter demonstrated two unique groups, represented by dense areas between 5 and 10cm^2 and between 150 and 250cm^2, while only one unique group was observed within the 5cm^2 area with the 1-4 isopter. No age or inheritance type of effect was seen. A-and b-wave amplitudes were equally low in the 3 groups, as compared with normal subjects. The b/a ratio was significantly smaller in the ADRP group, compared with the others. The rate of detectable ERG responses decreased as the visual field became smaller. There was no inheritance effect. A lower b/a ratio in ADRP patients suggested that retinal functional abnormalities differed from ARRP and simplex RP patients

    “Caracterización de los sistemas de producción de ovinos de pelo en el suroeste del departamento de Matagalpa 2010”

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    Con el objetivo de caracterizar los sistemas de producción de ovinos de pelo en el territorio suroeste del departamento de Matagalpa 2010. (Sébaco, Ciudad Darío, San Isidro y Matagalpa). Se aplicó una encuesta a 103 productores que poseen ovinos de pelo, la muestra se definió aleatoriamente utilizando la ecuación planteada por Scheaffer (1987), se utilizó la técnica de muestreo de bola de nieve, planteada por Frey et al (2000). Esta investigación permitió conocer las debilidades y oportunidades en los sistemas de explotación de esta especie promisoria para la zona seca del país. Con los resultados obtenidos de las encuestas se procedió ha elaborar una base de datos en el programa SPSS versión 11.5 en español. Encontrando un predominio del sexo femenino como titulares de las explotaciones ovinas, 58.3% cursó educación primaria, el 98% de las explotaciones cuentan con raza pelibuey, el 100% de las explotaciones realizan destete y monta de forma natural, una media de mortalidad de corderos de 1, alimentan a las ovejas con potrero sin división (81.6%), se suministra pasto de corte, pastoreo, leguminosas y se suplementa sal común 49.5%, aplican vacunas contra ántrax y pierna negra (63.1%), desparasitaciones internas y externas (66%), ambos con una frecuencia de 2 veces al año, en el manejo productivo no se lleva control en la actividad ovina (100%), los equipo e instalaciones son rústicas, los corrales ovinos el son elaborados con alambre y/o madera, techado con plástico y/o zinc (49.51%), en cuanto a asistencia técnica el 58.3% ha recibid

    Visualization 2.avi

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    the theoretical incident pupil fields and corresponding focused beams for the spin axis rotation in Fig. 8

    Freeze–Thaw Sample Preparation Method Improves Detection of Volatile Compounds in Insects Using Headspace Solid-Phase Microextraction

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    Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) is commonly used in analyzing insect volatiles. To improve the detection of volatiles in insects, a freeze–thaw method was applied to insect samples before the HS-SPME–GC–MS analysis. Insect samples were first frozen at −80 °C for 10 min and then thawed at 25 °C for 5 min before SPME extraction was performed. The freeze–thaw method clearly improved the detection of volatile compounds for all six tested insect species, including red imported fire ants, <i>Solenopsis invicta</i> Buren, black imported fire ants, <i>Solenopsis richteri</i> Forel, little black ants, <i>Monomorium minimum</i> (Buckley), pharaoh ants, <i>Monomorium pharaonis</i> (Linnaeus), eastern subterranean termites, <i>Reticulitermes flavipes</i> (Kollar), and spotted lady beetles, <i>Coleomegilla maculate</i> De Geer. This method helped identify various volatile compounds in the tested insects which have never been reported previously. This improved method may facilitate the identification of insect derived volatiles such as insect semiochemicals

    Life events and hopelessness depression: The influence of affective experience

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    <div><p>This study explored the association of the affective experience (AE) of life events on hopelessness depression (HD). Undergraduates (N = 301) participating in a 12-week prospective study completed measures of HD, cognitive style, and psychological stress. The results indicate AE is an underlying mechanism influencing the longitudinal link between life events and HD. Negative life events with clear negative AE directly promoted the development of HD. Positive life events with clear positive AE directly impeded the development of HD. Neutral life events with mixed AE directly and interacting with negative cognitive style promoted the development of HD. The results should increase understanding of the hopelessness theory of depression, and suggest that neutral life events should be important elements in depression therapy.</p></div

    Measurement techniques for mode detection in aeroengine inter-stage sections

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    The sound field within an aeroengine duct can be expressed as a superimposition of acoustic modes. Knowledge of the modal pressure amplitude is useful for providing insight into the noise generation mechanism, assist in the design of sound absorbing liners, and is invaluable for determining the sound power. In-duct modal analysis allows the amplitude of each modal component to be determined from the sound pressure measured at the duct wall. Previous research has demonstrated the feasibility of using axial microphone arrays to detect the modes in the tonal and broadband sound fields. Broadband noise generally comprises all propagating modes, which would require at least as many microphones to deduce the amplitude for each mode index pair (m,n). Most existing studies have focussed on the modal analysis of broadband noise at the inlet or bypass sections of aeroengines. Meanwhile, all existing modal analysis techniques assume that the modes in the sound field are mutually uncorrelated. It is commonly believed that the broadband noise is mainly generated from the interaction of wake turbulence from the rotor with the leading edge of the Outlet Guide Vane (OGV), and the interaction of the boundary turbulence with the trailing edge of rotor blade. However, no work has been undertaken into modal analysis based on measurements in the engine inter-stage section aimed at understanding this interaction noise mechanism. The space restriction of the inter-stage section constrains the number of microphones that can be used. Therefore, innovative measurement techniques must be developed which can detect the modes in the limited spacing between the rotor and the OGV. This paper investigates two different measurement techniques suitable for this purpose. The first is based on measurements of the coherence function of the acoustic pressure between two measurement positions at the duct wall. The second uses a beamformer formed from an axial array of microphones at the duct wall. In this paper we present a simple acoustic model for the sound field in the engine inter-stage due to a rotating fan and an OGV. The model has a number of simplifying assumptions but includes realistic spanwise correlation characteristics through the use of simple semi-empirical turbulence models, which is necessary for predicting the correct modal correlation behaviour. The swirl is treated simply as a rigid body rotation. Based on the simulated acoustic pressure at the duct wall, the actual mode amplitude distribution and the estimated mode amplitude distribution from two techniques are compared. The modal information is obtained in the form of the mode amplitude versus modal cuton ratio for both rotor and OGV. Thus, the methods are effective as a means of determining the dominant noise source in the engine. The relationship between the two methods is explored

    Effects of negative life events and negative cognitive style on hopelessness depression.

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    <p>Note: NLEs = Negative Life Events; NCS = Negative Cognitive Style; HD = Hopelessness Depression.</p

    Means, standard deviations, and intercorrelations of study variables.

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    <p>Means, standard deviations, and intercorrelations of study variables.</p

    Fixed effects.

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    <p>Fixed effects.</p

    Effects of neutral life events and cognitive style on hopelessness depression.

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    <p>Note: NeuLEs = Neutral Life Events; NCS = Negative Cognitive Style; ECS = Enhancing Cognitive Style; HD = Hopelessness Depression.</p
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