1,718 research outputs found

    Improvement of flowering in Calceolaria by cold treatment and selection.

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    Cold treatment for 4 weeks at 10 deg C resulted in shortening of the uneven flowering period as a consequence of a delay of the early-flowering and an advance of the late-flowering plants. For the selection material used, the effect was notably a delay of the early-flowering plants. The percentage of flowering plants was favourably influenced by cold treatment. The number of simultaneously flowering plants was also increased by selection, although to a lesser extent. (Abstract retrieved from CAB Abstracts by CABI’s permission

    Broadband hyperspectral imaging for breast tumor detection using spectral and spatial information

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    Complete tumor removal during breast-conserving surgery remains challenging due to the lack of optimal intraoperative margin assessment techniques. Here, we use hyperspectral imaging for tumor detection in fresh breast tissue. We evaluated different wavelength ranges and two classification algorithms; a pixel-wise classification algorithm and a convolutional neural network that combines spectral and spatial information. The highest classification performance was obtained using the full wavelength range (450-1650nm). Adding spatial information mainly improved the differentiation of tissue classes within the malignant and healthy classes. High sensitivity and specificity were accomplished, which offers potential for hyperspectral imaging as a margin assessment technique to improve surgical outcome. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

    From Soma to Synapse: Imaging Age-Related Rod Photoreceptor Changes in the Mouse with Visible Light OCT

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    PurposeAlthough the outer nuclear layer (ONL) and outer plexiform layer (OPL) each exhibit a complex internal organization, near-infrared OCT depicts both as monolithic bands. Here, using visible light OCT in the C57BL/6J mouse retina, sublaminar age-related changes in photoreceptor features were imaged and interpreted. These features were (1) oscillations in reflectivity, or striations, in the ONL and (2) a moderately reflective subband in the OPL.DesignCross-sectional study.ParticipantsPigmented mice (C57BL/6J, n = 14).MethodsA 1.0-μm axial resolution visible light spectral/Fourier domain OCT system was used for in vivo retinal imaging. Light and electron microscopy were performed ex vivo. Linear mixed effects models or regression were employed for statistical analysis.Main outcome measuresComparison of OCT subbands with corresponding histological features, as well as quantification of subband thickness and reflectivity.ResultsCorresponding histological comparisons confirm that striations in the ONL arise from the rowlike arrangement of photoreceptor nuclei and reveal that the moderately reflective OPL subband arises from rod spherules. Compression of outer ONL striations with age suggests changes in soma organization. Thinning of the moderately reflective OPL subband with age supports a reduction of synapses in the OPL. Critically, the ONL somas are tightly correlated with the purported spherule layer but not with the rest of the OPL.ConclusionsVisible light OCT imaging of the mouse OPL resolves postsynaptic and synaptic differences. Visible light OCT can study rod photoreceptor changes from the soma to the synapse in the living mouse retina.Financial disclosuresProprietary or commercial disclosure may be found after the references

    Method for coregistration of optical measurements of breast tissue with histopathology : the importance of accounting for tissue deformations

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    For the validation of optical diagnostic technologies, experimental results need to be benchmarked against the gold standard. Currently, the gold standard for tissue characterization is assessment of hematoxylin and eosin (H&E)-stained sections by a pathologist. When processing tissue into H&E sections, the shape of the tissue deforms with respect to the initial shape when it was optically measured. We demonstrate the importance of accounting for these tissue deformations when correlating optical measurement with routinely acquired histopathology. We propose a method to register the tissue in the H&E sections to the optical measurements, which corrects for these tissue deformations. We compare the registered H&E sections to H&E sections that were registered with an algorithm that does not account for tissue deformations by evaluating both the shape and the composition of the tissue and using microcomputer tomography data as an independent measure. The proposed method, which did account for tissue deformations, was more accurate than the method that did not account for tissue deformations. These results emphasize the need for a registration method that accounts for tissue deformations, such as the method presented in this study, which can aid in validating optical techniques for clinical use. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License

    Premi Asuransi Jiwa Gabungan Berjangka dengan Asumsi Gompertz

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    This article discusses the annual premium of term insurance for joint life. In this kind of insurance, the sum assured of two people insured with the age of and is paid if only one of the insureds dies during the coverage period and then no more premium payment. The annual premium is affected by single premium and present value of annuity due, where Gompertz assumption is used in calculation. A bigger premium is obtained using the Gompertz assumption
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