Specimen Preparation and Chamber for Confocal Microscopy of the Ex Vivo Eye

A chamber is described for maintaining the mechanical and physiological stability of the ex vivo eye during observation with confocal microscopy. The mechanical stability is provided by a plastic ring situated on the limbal region of the eye. The ring and supporting chamber are designed to reduce mechanical motion of the specimen. The ring and chamber size vary with the species and size of the eye under examination. The physiological stability over a period of approximately one hour is provided by immersing the eye in a bicarbonate Ringer\u27s solution that is exchanged every five minutes. This fluid exchange is made between periods of microscopic observation. The suggested method for confocal microscopic observation of cornea and ocular lens in an ex vivo eye is to use a non-contact water immersion microscopic objective with a high numerical aperture. This is a non-invasive, non-applanating system for the confocal microscopical observation of ex vivo rabbit or human eye. Sample preparation and the specimen chamber are described. Optical sections of the cornea and lens obtained with a confocal microscope from a freshly removed ex vivo rabbit eye are presented as examples of applications of this technique

Confocal Microscopy and Three-Dimensional Reconstruction of Thick, Transparent, Vital Tissue

The three-dimensional visualization of the 400 micron thick, transparent, in situ cornea is described to demonstrate the use of confocal light microscopy for noninvasive imaging of living cells and thick tissues in their normal, vital conditions. Specimen preparation and physiological stability, as well as light attenuation corrections are critical to data acquisition. The technique to provide mechanical stability of the specimen during the duration of the image acquisition is explained. A laser scanning confocal light microscope (LSCM) was used to obtain optical serial sections from rabbit eyes that were freshly removed and placed in a physiological Ringer\u27s solution. This study demonstrates the capability of the confocal light microscope to obtain a series of high contrast images, with a depth resolution of one micron, across the full thickness of living, transparent tissue. The problems of nonisotropic sampling and the limited eight-bit dynamic range are discussed. The three-dimensional reconstructions were obtained by computer graphics using the volume visualization projection technique. The three-dimensional visualization of the cornea in the in situ eye is presented as an example of image understanding of thick, viable biological cells and tissues. Finally, the criterion of image fidelity is explained. The techniques of confocal light microscopy with its enhanced lateral and axial resolution, improved image contrast, and volume visualization provides microscopists with new techniques for the observation of vital cells and tissues, both in vivo and in vitro

Photoacoustic Imaging and Spectroscopy [Book Review]

Photoacoustic Imaging and Spectroscopy is a multiauthored reference book that presents an advanced series of disparate chapters on the mathematical foundations, instrumentation, and applications of photoacoustic and thermoacoustic imaging. Lihong Wang, an eminent author, educator, scientist, and leader in the field of photoacoustic imaging and spectroscopy, is the editor of this book. Clearly this field is extremely active as evidenced by the diversity, the scope, and the quality of the field’s published literature. Nevertheless, I was surprised to read the back cover, which I think is overreaching with the claim that photoacoustics may make as dynamic a contribution to modern medicine as the discovery of the x ray once did. While this may be a “typical” overstatement by the publisher’s marketing team, it should be noted that within one year of the discovery of x rays there were more than one thousand publications related to the topic

Photoacoustic Imaging and Spectroscopy [Book Review]

Photoacoustic Imaging and Spectroscopy is a multiauthored reference book that presents an advanced series of disparate chapters on the mathematical foundations, instrumentation, and applications of photoacoustic and thermoacoustic imaging. Lihong Wang, an eminent author, educator, scientist, and leader in the field of photoacoustic imaging and spectroscopy, is the editor of this book. Clearly this field is extremely active as evidenced by the diversity, the scope, and the quality of the field’s published literature. Nevertheless, I was surprised to read the back cover, which I think is overreaching with the claim that photoacoustics may make as dynamic a contribution to modern medicine as the discovery of the x ray once did. While this may be a “typical” overstatement by the publisher’s marketing team, it should be noted that within one year of the discovery of x rays there were more than one thousand publications related to the topic

Regenerative agriculture in Aotearoa New Zealand - research pathways to build science-based evidence and national narratives.

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Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report

This report describes the 2014 study by the Science Definition Team (SDT) of the Wide-Field Infrared Survey Telescope (WFIRST) mission. It is a space observatory that will address the most compelling scientific problems in dark energy, exoplanets and general astrophysics using a 2.4-m telescope with a wide-field infrared instrument and an optical coronagraph. The Astro2010 Decadal Survey recommended a Wide Field Infrared Survey Telescope as its top priority for a new large space mission. As conceived by the decadal survey, WFIRST would carry out a dark energy science program, a microlensing program to determine the demographics of exoplanets, and a general observing program utilizing its ultra wide field. In October 2012, NASA chartered a Science Definition Team (SDT) to produce, in collaboration with the WFIRST Study Office at GSFC and the Program Office at JPL, a Design Reference Mission (DRM) for an implementation of WFIRST using one of the 2.4-m, Hubble-quality telescope assemblies recently made available to NASA. This DRM builds on the work of the earlier WFIRST SDT, reported by Green et al. (2012) and the previous WFIRST-2.4 DRM, reported by Spergel et. (2013). The 2.4-m primary mirror enables a mission with greater sensitivity and higher angular resolution than the 1.3-m and 1.1-m designs considered previously, increasing both the science return of the primary surveys and the capabilities of WFIRST as a Guest Observer facility. The addition of an on-axis coronagraphic instrument to the baseline design enables imaging and spectroscopic studies of planets around nearby stars.Comment: This report describes the 2014 study by the Science Definition Team of the Wide-Field Infrared Survey Telescope mission. 319 pages; corrected a misspelled name in the authors list and a typo in the abstrac

Intraneuronal Aβ immunoreactivity is not a predictor of brain amyloidosis-β or neurofibrillary degeneration

Amyloid β (Aβ) immunoreactivity in neurons was examined in brains of 32 control subjects, 31 people with Down syndrome, and 36 patients with sporadic Alzheimer’s disease to determine if intraneuronal Aβ immunoreactivity is an early manifestation of Alzheimer-type pathology leading to fibrillar plaque formation and/or neurofibrillary degeneration. The appearance of Aβ immunoreactivity in neurons in infants and stable neuron-type specific Aβ immunoreactivity in a majority of brain structures during late childhood, adulthood, and normal aging does not support this hypothesis. The absence or detection of only traces of reaction with antibodies against 4–13 aa and 8–17 aa of Aβ in neurons indicated that intraneuronal Aβ was mainly a product of α- and γ-secretases (Aβ(17–40/42)). The presence of N-terminally truncated Aβ(17–40) and Aβ(17–42) in the control brains was confirmed by Western blotting and the identity of Aβ(17–40) was confirmed by mass spectrometry. The prevalence of products of α- and γ -secretases in neurons and β- and γ-secretases in plaques argues against major contribution of Aβ-immunopositive material detected in neuronal soma to amyloid deposit in plaques. The strongest intraneuronal Aβ(17–42) immunoreactivity was observed in structures with low susceptibility to fibrillar Aβ deposition, neurofibrillary degeneration, and neuronal loss compared to areas more vulnerable to Alzheimer-type pathology. These observations indicate that the intraneuronal Aβ immunoreactivity detected in this study is not a predictor of brain amyloidosis or neurofibrillary degeneration. The constant level of Aβ immunoreactivity in structures free from neuronal pathology during essentially the entire life span suggests that intraneuronal amino-terminally truncated Aβ represents a product of normal neuronal metabolism

Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods - recursive partitioning and regression - to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; Pcombined = 2.01 × 10-19 and 2.35 × 10-13, respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes. ©2007 Nature Publishing Group

New Frontiers-class Uranus Orbiter: Exploring the feasibility of achieving multidisciplinary science with a mid-scale mission

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