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Praying mantids are models for a wide variety of behavioral, physiological, and ecological studies, and sex pheromones have been assumed to be important components of their biology. However, no mantid pheromone has ever been identified. We collected volatiles emitted by females of the mantid, Sphodromantis lineola, via solid phase microextraction (SPME). Mass spectral analysis revealed the collected volatiles to be a mixture of pentadecanal and tetradecanal. We prepared a synthetic mixture of these compounds, and found that males were both attracted to this mixture and stimulated to exhibit typical precopulatory behavior. We then examined male antennae with scanning electron microscopy, and confirmed the presence of porous antennal sensilla typical of insect pheromone receptors, i.e., that male mantids are equipped with the appropriate morphological apparatus to receive volatile chemical signals. Pheromones, in conjunction with visual and tactile cues, are thus an important feature of the reproductive biology of this, and undoubtedly other species of mantids. In addition to adding a crucial aspect of behavioral biology to our knowledge of this group, identification and synthesis of mantid pheromones may be a first step in attracting and aggregating these generalist predators for use in pest control. 相似文献
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We have performed angle-dependent reflectance measurements of in situ magnetron sputtered films of B(4)C, C, Mo, Si, and W. The Fresnel relations were used to determine the complex index of refraction from the reflectance data in the region of approximately 35-150 eV. In the cases of Si, C, and B(4)C we found excellent agreement with published data. However, for Mo and W we found that the optical properties from 35 to 60 eV differed significantly from those in the literature. 相似文献
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Sebastiani G Godtliebsen F Jones RA Haraldseth O Muller TB Rinck PA 《IEEE transactions on medical imaging》1996,15(3):268-277
Dynamic magnetic resonance (MR) imaging with contrast agents is a very promising technique for studying tissue perfusion in vivo. A temporal series of magnetic resonance images of the same slice are acquired following the injection of a contrast agent into the blood stream. The image intensity depends on the local concentration of the contrast agent, so that tissue perfusion can be studied by the image series. A new method of analyzing such series is described here. Nonparametric linear regression is used for modeling the image intensity along the series on a pixel by pixel basis. After modeling, some relevant quantities describing the time series are obtained and displayed as images. Due to its flexibility, this approach is preferred to parametric modeling when pathology is present since this can induce a wide spread of patterns for the pixel image intensity along time. Results of the application of the method to series of dynamic magnetic resonance images from ischaemic rat brains after the injection of the susceptibility agent Sprodiamide Inj. (Dy-DTPA-BMA) are shown and compared to results from a related known method. 相似文献
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The polarization properties of solid-state cube-corner retroreflectors, which are uncoated glass or metal-coated glass on the reflecting surfaces, are examined analytically and compared. Experimental verifications are presented for the case of linearly polarized incident light. When the uncoated cube-corner is used in a heterodyne interferometer, the polarization properties reveal that the axial orientation of the corner reflector has an effect on the strength of the beat signal and the nonlinearity error. A theoretical analysis of the effect is presented together with experimental results. 相似文献
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Armstrong MR Boyden K Browning ND Campbell GH Colvin JD DeHope WJ Frank AM Gibson DJ Hartemann F Kim JS King WE LaGrange TB Pyke BJ Reed BW Shuttlesworth RM Stuart BC Torralva BR 《Ultramicroscopy》2007,107(4-5):356-367
Although recent years have seen significant advances in the spatial resolution possible in the transmission electron microscope (TEM), the temporal resolution of most microscopes is limited to video rate at best. This lack of temporal resolution means that our understanding of dynamic processes in materials is extremely limited. High temporal resolution in the TEM can be achieved, however, by replacing the normal thermionic or field emission source with a photoemission source. In this case the temporal resolution is limited only by the ability to create a short pulse of photoexcited electrons in the source, and this can be as short as a few femtoseconds. The operation of the photo-emission source and the control of the subsequent pulse of electrons (containing as many as 5 x 10(7) electrons) create significant challenges for a standard microscope column that is designed to operate with a single electron in the column at any one time. In this paper, the generation and control of electron pulses in the TEM to obtain a temporal resolution <10(-6)s will be described and the effect of the pulse duration and current density on the spatial resolution of the instrument will be examined. The potential of these levels of temporal and spatial resolution for the study of dynamic materials processes will also be discussed. 相似文献
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Leamon TB 《Applied ergonomics》1980,11(3):161-164
The problem of introducing ergonomics into a major chemical industry was tackled by a novel approach which allowed the industry concerned access to a wide range of ergonomics skills. This allowed appropriate expertise to be applied as necessary to the variety of problems arising in the design of a plant. The problems included equipment design and layout, thermal, auditory and visual environments, job design and training aids. The difficulties of identifying the benefits of such an introduction were dealt with by the use of a senior management seminar which employed a 'paired presentation' format to describe both the various contributions made by the ergonomists to the industry and the evaluation by the individual recipients of such contributions. 相似文献