Comparison of Varying Tissue Freezing Methods on Murine Colonic Tissue

Histology often requires a tissue specimen to be embedded so that it may be sectioned, stained, and mounted on a microscope slide for viewing. One common method of tissue embedding for rapid histology is freezing, since freezing allows tissue to be stored without the need for fixing. Frozen tissue is often embedded in a medium such as Optimal Cutting Temperature (OCT) compound so that it can be sectioned using a cryostat. However, factors such as ice-crystal formation during the freezing process can cause damage to the tissue. As such, the protocol used to freeze the tissue can affect the quality of the slides. The purpose of this project is to compare different freezing methods and examine their strengths and weaknesses when applied to murine colonic tissue. Murine colonic tissue was frozen using two snap-freezing methods, piezoelectric freezing, and two different cold storage methods, each with their own three to four variations. Transverse sections were made in a cryostat, which were mounted on slides and stained using a hematoxylin and eosin (H&E) staining protocol. The sections were then imaged using a light microscope. A blind test was conducted to rate the image quality and inter-rater agreement was calculated using Fleiss’s Kappa. Paraffin embedding obtained the highest score, while OCT embedding inside a -80°C freezer received the second highest score

Spatiotemporal evolution, mineralogical composition, and transport mechanisms of long-runout landslides in Valles Marineris, Mars

Long-runout landslides with transport distances of >50 km are ubiquitous in Valles Marineris (VM), yet the transport mechanisms remain poorly understood. Four decades of studies reveal significant variation in landslide morphology and emplacement age, but how these variations are related to landslide transport mechanisms is not clear. In this study, we address this question by conducting systematic geological mapping and compositional analysis of VM long-runout landslides using high-resolution Mars Reconnaissance Orbiter imagery and spectral data. Our work shows that: (1) a two-zone morphological division (i.e., an inner zone characterized by rotated blocks and an outer zone expressed by a thin sheet with a nearly flat surface) characterizes all major VM landslides; (2) landslide mobility is broadly dependent on landslide mass; and (3) the maximum width of the outer zone and its transport distance are inversely related to the basal friction that was estimated from the surface slope angle of the outer zone. Our comprehensive Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) compositional analysis indicates that hydrated silicates are common in landslide outer zones and nearby trough-floor deposits. Furthermore, outer zones containing hydrated minerals are sometimes associated with longer runout and increased lateral spreading compared to those without detectable hydrated minerals. Finally, with one exception we find that hydrated minerals are absent in the inner zones of the investigated VM landslides. These results as whole suggest that hydrated minerals may have contributed to the magnitude of lateral spreading and long-distance forward transport of major VM landslides

Emeritus Professor J.N. Hutchinson : Historical Landslide Collection : Great Britain

This report describes a collection of material, field documents, aerial photographs, reports, maps and reference material, which was bequeathed to the British Geological Survey by Professor J. N. Hutchinson. Any material pertaining to Great Britain was sorted into geographical regions and catalogued with the remaining material archived within the National GeoSceince Data Centre to be catalogued at a later date

Twenty-first century brain banking. Processing brains for research: the Columbia University methods

Carefully categorized postmortem human brains are crucial for research. The lack of generally accepted methods for processing human postmortem brains for research persists. Thus, brain banking is essential; however, it cannot be achieved at the cost of the teaching mission of the academic institution by routing brains away from residency programs, particularly when the autopsy rate is steadily decreasing. A consensus must be reached whereby a brain can be utilizable for diagnosis, research, and teaching. The best diagnostic categorization possible must be secured and the yield of samples for basic investigation maximized. This report focuses on integrated, novel methods currently applied at the New York Brain Bank, Columbia University, New York, which are designed to reach accurate neuropathological diagnosis, optimize the yield of samples, and process fresh-frozen samples suitable for a wide range of modern investigations. The brains donated for research are processed as soon as possible after death. The prosector must have a good command of the neuroanatomy, neuropathology, and the protocol. One half of each brain is immersed in formalin for performing the thorough neuropathologic evaluation, which is combined with the teaching task. The contralateral half is extensively dissected at the fresh state. The anatomical origin of each sample is recorded using the map of Brodmann for the cortical samples. The samples are frozen at −160°C, barcode labeled, and ready for immediate disbursement once categorized diagnostically. A rigorous organization of freezer space, coupled to an electronic tracking system with its attached software, fosters efficient access for retrieval within minutes of any specific frozen samples in storage. This report describes how this achievement is feasible with emphasis on the actual processing of brains donated for research

Color changes upon cooling of Lepidoptera scales containing photonic nanoarchitectures, and a method for identifying the changes

The effects produced by the condensation of water vapor from the environment in the various intricate nanoarchitectures occurring in the wing scales of several Lepidoptera species were investigated by controlled cooling (from 23° C, room temperature to -5 to -10° C) combined with in situ measurements of changes in the reflectance spectra. It was determined that all photonic nanoarchitectures giving a reflectance maximum in the visible range and having an open nanostructure exhibited alteration of the position of the reflectance maximum associated with the photonic nanoarchitectures. The photonic nanoarchitectures with a closed structure exhibited little to no alteration in color. Similarly, control specimens colored by pigments did not exhibit a color change under the same conditions. Hence, this method can be used to identify species with open photonic nanoarchitectures in their scales. For certain species, an almost complete disappearance of the reflectance maximum was found. All specimens recovered their original colors following warming and drying. Cooling experiments using thin copper wires demonstrated that color alterations could be limited to a width of a millimeter or less. Dried museum specimens did not exhibit color changes when cooled in the absence of a heat sink due to the low heat capacity of the wings

Growth and mass wasting of volcanic centers in the northern South Sandwich arc, South Atlantic, revealed by new multibeam mapping

New multibeam (swath) bathymetric sonar data acquired using an EM120 system on the RRS James Clark Ross, supplemented by sub-bottom profiling, reveals the underwater morphology of a not, vert, similar 12,000 km2 area in the northern part of the mainly submarine South Sandwich volcanic arc. The new data extend between 55° 45′S and 57° 20′S and include Protector Shoal and the areas around Zavodovski, Visokoi and the Candlemas islands groups. Each of these areas is a discrete volcanic center. The entirely submarine Protector Shoal area, close to the northern limit of the arc, forms a 55 km long east–west-trending seamount chain that is at least partly of silicic composition. The seamounts are comparable to small subaerial stratovolcanoes in size, with volumes up to 83 km3, indicating that they are the product of multiple eruptions over extended periods. Zavodovski, Visokoi and the Candlemas island group are the summits of three 3–3.5 km high volcanic edifices. The bathymetric data show evidence for relationships between constructional volcanic features, including migrating volcanic centers, structurally controlled constructional ridges, satellite lava flows and domes, and mass wasting of the edifices. Mass wasting takes place mainly by strong erosion at sea level, and dispersal of this material along chutes, probably as turbidity currents and other mass flows that deposit in extensive sediment wave fields. Large scale mass wasting structures include movement of unconsolidated debris in slides, slumps and debris avalanches. Volcanism is migrating westward relative to the underlying plate and major volcanoes are asymmetrical, being steep with abundant recent volcanism on their western flanks, and gently sloping with extinct, eroded volcanic sequences to their east. This is consistent with the calculated rate of subduction erosion of the fore-arc

Pisces IV submersible observations in the epicentral region of the 1929 Grand Banks earthquake

The PISCES IVsubmersible was used to investigate the upper continental slope around 44 ON, 56 W, near the epicentre of the 1929 Grand Banks earthquake. Four dives in water depths of 800-2000 m were undertaken to observe speci3c features identijied with the SeaMARC I sidescan system in 1983. Two dives were made in the head of Eastern Valley where pebbly mudstones ofprobable Pleistocene age were recognized outcropping on the seafloor. Constructional features of cobbles and boulders, derived by exhumation and reworking of the pebbly mudstone, were also observed. These include gravel/sand bedforms (transverse waves) on the valley floor. Slope failure features in semiconsolidated mudstone were recognized on two dives onto the St. Pierre slope. Exposures in these mudstones are rapidly eroded by intense burrowing by benthic organisms

Colour changes upon cooling of Lepidoptera scales containing photonic nanoarchitectures

The effects produced by the condensation of water vapours from the ambient in the various intricate nanoarchitectures occurring in the wing scales of several Lepidoptera species were investigated by controlled cooling (from room temperature to -5 - -10 {\deg}C) combined with in situ measurement of changes in the reflectance spectra. It was determined that, due to this procedure, all photonic nanoarchitectures giving a reflectance maximum in the visible range and having an open nanostructure exhibited alteration of the position of the reflectance maximum associated with the photonic nanoarchitectures. The photonic nanoarchitectures with a closed structure exhibited little to no alteration in colour. Similarly, control specimens coloured by pigments did not exhibit a colour change under the same conditions. Hence, this effect can be used to identify species with open photonic nanoarchitectures in their scales. For certain species, an almost complete disappearance of the reflectance maximum was found. All specimens recovered their original colours following warming and drying. Cooling experiments using thin copper wires demonstrated that colour alterations could be limited to a millimetre, or below. Dried museum specimens do not exhibit colour changes when cooled in the absence of a heat sink due to the low heat capacity of the wings.Comment: 18 pages, 9 figures, including supplemen

Methods in soil micromorphology : a technique for the preparation of large thin sections

Stiboka onderzoe

Workpiece positioning vise

A pair of jaw assemblies simultaneously driven in opposed reciprocation by a single shaft has oppositely threaded sections to automatically center delicate or brittle workpieces such as lithium fluoride crystal beneath the blade of a crystal cleaving machine. Both jaw assemblies are suspended above the vise bed by a pair of parallel guide shafts attached to the vise bed. Linear rolling bearings, fitted around the guide shafts and firmly held by opposite ends of the jaw assemblies, provide rolling friction between the guide shafts and the jaw assemblies. A belleville washer at one end of the drive shaft and thrust bearings at both drive shaft ends hold the shaft in compression between the vise bed, thereby preventing wobble of the jaw assemblies due to wear between the shaft and vise bed