Original Spatial Relationship Research Articles

Contrasting constraints on the temporal and spatial extents of normal faults from the Hilltop and Lewis mining districts, northern Shoshone Range, Nevada, USA

Mapping of rock types, structural geology, and hydrothermal alteration, supported by geochronology and thermochronology, sheds light on the original spatial relationships of hydrothermal systems to intrusions in the northern Shoshone Range in north-central Nevada. Rocks in the Hilltop district are tilted ~35–40°E, as indicated by orientations of flattened pumice fiamme and bedding in sedimentary rocks along a single set of presently low-angle normal faults that initiated at 60–70°W dips. New U-Pb zircon geochronology from two sets of dikes in the Lewis district could suggest late Eocene–early Oligocene extension, but definitive crosscutting relations are lacking to demonstrably support this potential earlier period of normal faulting. Reinterpretation of previously reported apatite fission-track cooling ages with a new palinspastic restoration in the Lewis mining district concurs with middle Miocene extension as documented to the south at the Caetano caldera; however, the depth of burial of the Lewis district—and thus the significance of the apatite fission-track cooling ages—is uncertain. The comparable orientations and tilting history, supported by fault scaling relations, suggest that the temporally coincident extension in the Caetano caldera to the south represents the along-strike continuation of the same system of normal faults as in the Hilltop and Lewis districts, with changes in observed offset, percent extension, and fault spacing attributed to the gradual tipping out of the fault system northward.

A Novel Fully Convolutional Auto-Encoder Based on Dual Clustering and Latent Feature Adversarial Consistency for Hyperspectral Anomaly Detection

With the development of artificial intelligence, the ability to capture the background characteristics of hyperspectral imagery (HSI) has improved, showing promising performance in hyperspectral anomaly detection (HAD) tasks. However, existing methods proposed in recent years still suffer from certain limitations: (1) Constraints are lacking in the deep feature learning process in terms of the issue of the absence of prior background and anomaly information. (2) Hyperspectral anomaly detectors with traditional self-supervised deep learning methods fail to ensure prioritized reconstruction of the background. (3) The architecture of fully connected deep networks in hyperspectral anomaly detectors leads to low utilization of spatial information and the destruction of the original spatial relationship in hyperspectral imagery and disregards the spectral correlation between adjacent pixels. (4) Hypotheses or assumptions for background and anomaly distributions restrict the performance of many hyperspectral anomaly detectors because the distributions of background land covers are usually complex and not assumable in real-world hyperspectral imagery. In consideration of the above problems, in this paper, we propose a novel fully convolutional auto-encoder based on dual clustering and latent feature adversarial consistency (FCAE-DCAC) for HAD, which is carried out with self-supervised learning-based processing. Firstly, density-based spatial clustering of applications with a noise algorithm and connected component analysis are utilized for successive spectral and spatial clustering to obtain more precise prior background and anomaly information, which facilitates the separation between background and anomaly samples during the training of our method. Subsequently, a novel fully convolutional auto-encoder (FCAE) integrated with a spatial–spectral joint attention (SSJA) mechanism is proposed to enhance the utilization of spatial information and augment feature expression. In addition, a latent feature adversarial consistency network with the ability to learn actual background distribution in hyperspectral imagery is proposed to achieve pure background reconstruction. Finally, a triplet loss is introduced to enhance the separability between background and anomaly, and the reconstruction residual serves as the anomaly detection result. We evaluate the proposed method based on seven groups of real-world hyperspectral datasets, and the experimental results confirm the effectiveness and superior performance of the proposed method versus nine state-of-the-art methods.

FONT-SIR: Fourth-Order Nonlocal Tensor Decomposition Model for Spectral CT Image Reconstruction.

Spectral computed tomography (CT) reconstructs images from different spectral data through photon counting detectors (PCDs). However, due to the limited number of photons and the counting rate in the corresponding spectral segment, the reconstructed spectral images are usually affected by severe noise. In this paper, we propose a fourth-order nonlocal tensor decomposition model for spectral CT image reconstruction (FONT-SIR). To maintain the original spatial relationships among similar patches and improve the imaging quality, similar patches without vectorization are grouped in both spectral and spatial domains simultaneously to form the fourth-order processing tensor unit. The similarity of different patches is measured with the cosine similarity of latent features extracted using principal component analysis (PCA). By imposing the constraints of the weighted nuclear and total variation (TV) norms, each fourth-order tensor unit is decomposed into a low-rank component and a sparse component, which can efficiently remove noise and artifacts while preserving the structural details. Moreover, the alternating direction method of multipliers (ADMM) is employed to solve the decomposition model. Extensive experimental results on both simulated and real data sets demonstrate that the proposed FONT-SIR achieves superior qualitative and quantitative performance compared with several state-of-the-art methods.

Interactive multi‐character motion retargeting

AbstractA motion retargeting process is necessary as the body size and proportion of the actors are generally different from those of the target characters. However, the original spatial relationship between the multiple characters and the environment is easily broken when using previous motion retargeting methods, which are generally performed for each character independently. Therefore, time‐consuming manual adjustments by animators are usually required to obtain satisfactory results. To address these issues, we present a novel multicharacter motion retargeting method that preserves various types of spatial relationships between characters and environments. We establish a unified deformation‐based framework for the motion retargeting of multiple characters (more than two) or nonhuman characters with complex interactions. Also, an interactive motion editing interface with immediate feedback to the user is provided. We experimentally show that our method achieves a speedup when compared with previous motion retargeting methods.

Displacement Analysis of Myocardial Mechanical Deformation (DIAMOND) Reveals Segmental Heterogeneity of Cardiac Function in Embryonic Zebrafish.

Zebrafish are increasingly utilized as a model organism for cardiomyopathies and regeneration. Current methods evaluating cardiac function fail to reliably detect segmental mechanics and are not readily feasible in zebrafish. Here we present a semiautomated, open-source method for the quantitative assessment of four-dimensional (4D) segmental cardiac function: displacement analysis of myocardial mechanical deformation (DIAMOND). Transgenic embryonic zebrafish were imaged in vivo using a light-sheet fluorescence microscopy system with 4D cardiac motion synchronization. Acquired 3D digital hearts were reconstructed at end-systole and end-diastole, and the ventricle was manually segmented into binary datasets. Then, the heart was reoriented and isotropically resampled along the true short axis, and the ventricle was evenly divided into eight portions (I-VIII) along the short axis. Due to the different resampling planes and matrices at end-systole and end-diastole, a transformation matrix was applied for image registration to restore the original spatial relationship between the resampled systolic and diastolic image matrices. After image registration, the displacement vector of each segment from end-systole to end-diastole was calculated based on the displacement of mass centroids in three dimensions (3D). DIAMOND shows that basal myocardial segments adjacent to the atrioventricular canal undergo the highest mechanical deformation and are the most susceptible to doxorubicin-induced cardiac injury. Overall, DIAMOND provides novel insights into segmental cardiac mechanics in zebrafish embryos beyond traditional ejection fraction (EF) under both physiological and pathological conditions.

Trabajos previos y paralelos integrados en el proyecto de restauración de la capilla de los Tocino (s. XV) en la iglesia de San Juan de los Caballeros de Jerez de la Frontera

Consecuencia de una profunda reforma decimonónica inacabada, la capilla de los Tocino había perdido su uso y relación espacial original con el ábside de la iglesia de San Juan de los Caballeros de Jerez de la Frontera al que se adosa. La degradación que sufrió la capilla desde ese momento fue enorme. La interpretación de sus lesiones estaba muy condicionada por el devenir del mismo, siendo necesaria una serie de trabajos previos y paralelos a la intervención para reconocer esta complejidad y determinar los valores patrimoniales sobre los que fundamentar el proyecto. Se planteó así una estrategia de acciones de investigación cuyo alcance debía ser proporcional a los recursos económicos disponibles y los enfoques analíticos que pretendíamos integrar. Entre ellas se programó una intervención arqueológica que incorporaba el análisis del subsuelo y estudio paramental. Se expondrá el resultado de un trabajo integrado que se prolongó hasta finalizar su consolidación material, espacial y funcional.

The stratigraphic record of minibasin subsidence, Precaspian Basin, Kazakhstan

AbstractMinibasins are fundamental components of many salt‐bearing sedimentary basins, where they may host large volumes of hydrocarbons. Although we understand the basic mechanics governing their subsidence, we know surprisingly little of how minibasins subside in three‐dimensions over geological timescales, or what controls such variability. Such knowledge would improve our ability to constrain initial salt volumes in sedimentary basins, the timing of salt welding and the distribution and likely charging histories of suprasalt hydrocarbon reservoirs. We use 3D seismic reflection data from the Precaspian Basin, onshore Kazakhstan to reveal the subsidence histories of 16, Upper Permian‐to‐Triassic, suprasalt minibasins. These minibasins subsided into a Lower‐to‐Middle Permian salt layer that contained numerous relatively strong, clastic‐dominated minibasins encased during an earlier, latest Permian phase of diapirism; because of this, the salt varied in thickness. Suprasalt minibasins contain a stratigraphic record of symmetric (bowl‐shaped units) and then asymmetric (wedge‐shaped units) subsidence, with this change in style seemingly occurring at different times in different minibasins, and most likely prior to welding. We complement our observations from natural minibasins in the Precaspian Basin with results arising from new physical sandbox models; this allows us to explore the potential controls on minibasin subsidence patterns, before assessing which of these might be applicable to our natural example. We conclude that due to uncertainties in the original spatial relationships between encased and suprasalt minibasins, and the timing of changes in style of subsidence between individual minibasins, it is unclear why such complex temporal and spatial variations in subsidence occur in the Precaspian Basin. Regardless of what controls the observed variability, we argue that vertical changes in minibasin stratigraphic architecture may not record the initial (depositional) thickness of underlying salt or the timing of salt welding; this latter point is critical when attempting to constrain the timing of potential hydraulic communication between sub‐salt source rocks and suprasalt reservoirs. Furthermore, temporal changes in minibasin subsidence style will likely control suprasalt reservoir distribution and trapping style.

Evaluation of centering ability of XP endo shaper, Edge Evolve and Hyflex CM in simulated curved canals (A comparative study)

Background and objectives: Cleaning and shaping principles of root canal must aim to respect the continuously tapering funnel from the root apex to the coronal access cavity, follow the original canal shape and maintain the apical foramen in its original spatial relationship to the periapical tissues and root surface. This study was conducted to compare centering ability using: XP endo shaper, Edge Evolve and Hyflex CM nickeltitanium instruments in simulated curved canals. Materials and methods: Sixty simulated curved canals of 40°curvature were divided into three groups and prepared to an apical size 30 using single-length technique for XP endo shaper, crown-down technique for Edge Evolve and Hyflex CM instruments. Centering ability was evaluated; the measurements were carried out at five different levels. Pre-and postoperative images of the canals were taken at a standardized position by a digital camera (Nikon D810 – 36 Megapixels, Japan) with 60mm macro lens. An assessment of the shape of the canal was determined using AutoCAD sofware. The data were analyzed statistically using one way ANOVA, Welch ANOVA, Least significant differences (LSD) and Games-Howell post hoc test. Results: the results of this study demonstrated that the Edge Evolve instruments showed a significantly better centering ability than both XP endo shaper and Hyflex CM at four levels of measurements except at last level (HO) which XP endo shaper scores the best centering ability. The Hyflex CM and XP endo shaper instruments scores similar results and were mostly close to each other after Edge Evolve instruments regarding canal centering ratio. Conclusions: The study demonstrated that Edge Evolve file maintained curvature significantly better than Hyflex CM and XP endo shaper files.

A solution method for image distortion correction model based on bilinear interpolation

In the process of the image generation, because the imaging system itself has differences in terms of nonlinear or cameraman perspective, the generated image will face the geometric distortion. Image distortion in general is also a kind of image degradation, which needs the geometric transform to correct each pixel position of the distorted images, so as to regain the original spatial relationships between pixels and the original grey value relation, and which is also one of important steps of image processing. From the point of view of the digital image processing, the distortion correction is actually a process of image restoration for a degraded image. In image processing, in terms of the image quality improvement and correction technology, namely the image restoration, with the wide expansion of digital image distortion correction processing applied, the processing technology of the image restoration has also become a research hotspot. In view of the image distortion issue, this paper puts forward the image distortion correction algorithm based on two-step and one-dimensional linear gray level interpolation to reduce the computation complexity of the bilinear interpolation method, and divide the distorted image into multiple quadrilaterals, and the area of the quadrilateral is associated with the distortion degree of the image in the given region, and express the region distortion of each quadrilateral with the bilinear model, thus determining parameters of bilinear model according to the position of the quadrilateral vertex in the target image and the distorted image. Experiments show that such algorithm in this paper can meet the requirements of distortion correction of most lenses, which can accurately extract the distorted edge of the image, thus making the corrected image closer to the ideal image.

Spatial regularization in subspace learning for face recognition: implicit vs. explicit

In applying traditional statistical method to face recognition, each original face image is often vectorized as a vector. But such a vectorization not only leads to high-dimensionality, thus small sample size (SSS) problem, but also loses the original spatial relationship between image pixels. It has been proved that spatial regularization (SR) is an effective means to compensate the loss of such relationship and at the same time, and mitigate SSS problem by explicitly imposing spatial constraints. However, SR still suffers from two main problems: one is high computational cost due to high dimensionality and the other is the selection of the key regularization factors controlling the spatial regularization and thus learning performance. Accordingly, in this paper, we provide a new idea, coined as implicit spatial regularization (ISR), to avoid losing the spatial relationship between image pixels and deal with SSS problem simultaneously for face recognition. Different from explicit spatial regularization (ESR), which introduces directly spatial regularization term and is based on vector representation, the proposed ISR constrains spatial smoothness within each small image region by reshaping image and then executing 2D-based feature extraction methods. Specifically, we follow the same assumption as made in SSSL (a typical ESR method) that a small image region around an image pixel is smooth, and reshape each original image into a new matrix whose each column corresponds to a vectorized small image region, and then we extract features from the newly-formed matrix using any off-the-shelf 2D-based method which can take the relationship between pixels in the same row or column into account, such that the original spatial relationship within the neighboring region can be greatly retained. Since ISR does not impose constraint items, compared with ESR, ISR not only avoids the selection of the troublesome regularization parameter, but also greatly reduces computational cost. Experimental results on four face databases show that the proposed ISR can achieve competitive performance as SSSL but with lower computational cost.

A summary-statistic model of the visual periphery predicts the difficulty of visual curve tracing

Observers can quickly and accurately report if two dots lie on the same contour, however task difficulty can vary substantially with the curvature and density of contours. Judging such spatial relationships is thought to require “visual routines” (Ullman, 1984), which are basic operations for marking items, diffusing activation within a region, or tracing a contour. Performance across a range of stimulus conditions has previously been modeled as an explicit tracing process in which a “zoom lens” rapidly moves along the contour between target dots. Though this model accounts well for human performance, its relationship to the human visual system is unclear. We propose that curve-tracing difficulty does not follow directly from constraints upon a high-level tracing “routine,” but may instead hinge on low-level information that is lost in peripheral vision (Balas et al., JOV 2009). Our model assumes that the visual system computes texture-like summary statistics in the periphery and estimates appearance from this lossy code. We assume that texture features are measured within peripheral pooling regions that scale with eccentricity in accordance with Bouma's Law. We first replicated previously-reported behavioral effects of contour density and curvature on “same-contour” tasks in human observers. We extend our previous methodology (Rosenholtz et al. VSS Symposium, 2010) to generate images that match the experimental stimuli in terms of local texture statistics. These images reflect what the stimuli “look like” to our model. We calculated d′ values for the model by observing how often the synthesized images preserved the original spatial relationship between the target dots. Our model's d′ scores capture the behavioral effects exhibited by human subjects, suggesting that performance in this task may be explicable by the lossy encoding of peripheral vision and consequent ambiguities imposed upon appearance.

Geology and tectonostratigraphy of the Onverwacht Suite, Barberton Greenstone Belt, South Africa

A synthesis of new and existing data reveals that at least seven major shear zones and an unconformity separate the rocks of the southern Barberton Greenstone Belt into seven units with different geological histories. Current views that these units constitute a continuous stratigraphic sequence and their subdivision into successive formations cannot be maintained. We argue here that the status of the traditional ‘formations’ of the Onverwacht Group of the Barberton Greenstone Belt be changed to ‘complexes’, and collectively these complexes be referred to as the Onverwacht Suite. The total age range and tectonostratigraphic thickness of the suite is about 120 million years and 15km, respectively. The precise age range of the rocks present in each complex is largely unknown. The original spatial relationships between the complexes can in most cases only be inferred.All of the complexes include significant volumes of intrusions that were emplaced into the volcanic and volcaniclastic host rocks. The ages of the intrusions in the different complexes vary. In some complexes the intrusions and volcanic rocks have similar geochemistry and are probably co-magmatic. Others provide ‘stitching’ ages between complexes. Four of the complexes display internal relationships that resemble ophiolites. Basaltic pillowed and massive lavas are the most common rock types. Sheeted dykes are generally absent whilst multiple mafic sills are common and dominate one of the complexes. The volcanology and geochemistry of the complexes suggest that they formed predominantly in oceanic spreading and intra-oceanic arc environments at water depths of 1.7–4km.The complexes were tectonically stacked during the final stages of their development, and during two subsequent orogenic events. One complex (the Hooggenoeg Complex) was uplifted and deeply eroded between about 3460 and 3470Ma, with a minimum uplift rate (ca. 0.5mm/yr) similar to that during emplacement of Phanerozoic ophiolites. Unconformably overlying, sub-aerial, coarse clastic sedimentary rocks (part of the newly distinguished Noisy Complex) overlap in age with felsic-intermediate igneous activity dated between 3445 and 3460Ma that, in turn, is genetically related to tonalite-trondjemite plutons exposed farther to the south.The emergence of the deep water Hooggenoeg Complex above sea level, the start of its erosion and fluvial sedimentation on top of it at ca. 3458Ma, represents the onset of its obduction onto older complexes, some of which are now preserved as enclaves in the granitoid terrains to the south. Other oceanic slabs (the Kromberg and the Mendon Complexes) were subsequently emplaced onto the Noisy Complex, during latitudinal displacements (ca. 12cm/yr) that were not notably faster than today.Exhumation, with up to 18km of unroofing along the southern margin of the greenstone belt, took place during a second orogenic episode of subduction and accretion between 3140 and 3230Ma. This episode was associated with folding, thrusting and molasse-type sedimentation within the greenstone belt, coupled to extension and ductile faulting at a lower crustal level. During this period, younger complexes were assembled, and the older complexes re-cycled and eroded, at rates and with geotherms comparable to those in modern orogenic belts.In the Barberton region between 3.2 and 3.5Ga tectonic processes appear to have operated at rates similar to those within modern evolving plate boundaries.

Volume Parameterization for Design Automation of Customized Free-Form Products

This paper addresses the problem of volume parameterization that serves as the geometric kernel for design automation of customized free-form products. The purpose of volume parameterization is to establish a mapping between the spaces that are near to two reference free-form models, so that the shape of a product presented in free-form surfaces can be transferred from the space around one reference model to another reference model. The mapping is expected to keep the spatial relationship between the product model and reference models as much as possible. We separate the mapping into rigid body transformation and elastic warping. The rigid body transformation is determined by anchor points defined on the reference models using a least-squares fitting approach. The elastic warping function is more difficult to obtain, especially when the meshes of the reference objects are inconsistent. A three-stage approach is conducted. First, a coarse-level warping function is computed based on the anchor points. In the second phase, the topology consistency is maintained through a surface fitting process. Finally, the mapping of volume parameterization is established on the surface fitting result. Compared to previous methods, the approach presented here is more efficient. Also, benefitting from the separation of rigid body transformation and elastic warping, the transient shape of a transferred product does not give unexpected distortion. At the end of this paper, various industry applications of our approach in design automation are demonstrated. Note to Practitioners-The motivation of this research is to develop a geometric solution for the design automation of customized free-form objects, which can greatly improve the efficiency of design processes in various industries involving customized products (e.g., garment design, toy design, jewel design, shoe design, and glasses design, etc.). The products in the above industries are usually composed of a very complex geometry shape (represented by free-form surfaces), and is not driven by a parameter table but a reference object with free-form shapes (e.g., mannequin, toy, wrist, foot, and head models). After carefully designing a product around one particular reference model, it is desirable to have an automated tool for "grading" this product to other shape-changed reference objects while retaining the original spatial relationship between the product and reference models. This is called the design automation of a customized free-form object. Current commercial 3-D/2-D computer-aided design (CAD) systems, developed for the design automation of models with regular shape, cannot support the design automation in this manner. The approach in this paper develops efficient techniques for constraining and reconstructing a product represented by free-form surfaces around reference objects with different shapes, so that this design automation problem can be fundamentally solved. Although the approach has not been integrated into commercial CAD systems, the results based on our preliminary implementation are encouraging-the spatial relationship between reference models and the customized products is well preserved

The innervation of FGF-induced additional limbs in the chick embryo.

Motoneurones that supply the vertebrate limb innervate their muscle targets in a highly reproducible manner. As development proceeds, these limb-specific motoneurones send out axons, which grow towards the developing limb and then congregate at its base to form the plexus. In the plexus, in response to unknown positional cues, these axons rearrange, often changing their original spatial relationships, before sorting out to emerge in the defined nerve trunks that innervate the limb. Several proposals have been put forward to explain how this reproducible innervation pattern is achieved. These include (1) that early differences in the motoneurone identity dictate their future axonal trajectories, (2) that axons actively respond to attractive or repulsive positional cues provided by the limb bud itself, or (3) that motor axons are passively deployed, following pathways of least mechanical resistance. We have addressed the question of the relative roles of motoneurone identity and the signals that the axons encounter on their journey towards the limb bud. Using the developing chick embryo as our experimental model we tested the effect of providing an additional limb target for motor axons leaving the flank level of the spinal cord. To do this we placed FGF-soaked beads in the presumptive flank of 2-day-old chick embryos. This treatment induces an additional limb containing muscles. We investigated whether such additional limbs are innervated and by which neurones. We show that rather than the additional limbs being solely supplied by axons diverted from the two existing limb plexuses, motoneurones that normally supply the flank alter their trajectories to enter the induced limb. Once in the limb, axons respond to positional cues within the bud to generate the stereotypical innervation pattern. Our results show that the tendency of 'flank' motoneurones to innervate flank can be overcome by the presence of an additional limb.

Redistribution of DNA topoisomerase II beta after in vitro stabilization of human erythroleukemic nuclei by heat or Cu++ revealed by confocal microscopy.

Using confocal laser scanning microscope and a monoclonal antibody we have examined by means of indirect immunofluorescence techniques the distribution of DNA topoisomerase II beta (the 180-kDa nucleolar isoform of topoisomerase II) following stabilization of isolated nuclei by exposure to moderate heat (37 degrees or 42 degrees C) or Cu++. In intact cells the antibody specifically decorated the nucleoli. The same pattern was maintained if nuclei were incubated at 0 degree C in a buffer containing spermine/spermidine/KCl or stabilized by means of 0.5 mM Cu++ for 10 minutes at 0 degree C in the same buffer. On the contrary, if stabilization was performed by incubating the nuclei either at 37 degrees or 42 degrees C, the immunoreactivity dispersed all over the nucleus, forming numerous speckles. This phenomenon was not detected if, in addition to spermine/spermidine/KCl, the incubation buffer also contained 5 mM Mg++ and the temperature was 37 degrees C. If the stabilization was performed at 42 degrees C, Mg++ failed to maintain the original distribution of DNA topoisomerase II beta, as seen in intact cells. The analysis on 2-D optical section showed the alteration of the nucleolar profile, particularly at 37 degrees C, even when the samples were treated with Mg++. The 3-D reconstruction figured out the irregularity of the surface at 37 degrees C and the variations of the volume occupied by the fluorescent figures. These were in close proximity to each other both in intact cells and in 0 degree C incubated nuclei; they showed a certain degree of shrinkage in 0 degree C plus Cu++ exposed samples (-20% of the volume), and, on the contrary, the labeled structures were scattered in a volume increased two- or threefold when exposed to 37 degrees or 42 degrees C, respectively. The addition of Mg++ restored the original spatial relationship and volume at 37 degrees C, but not at 42 degrees C, where the volumetric analysis showed an increase of about 50%. Our results demonstrate that heat stabilization of isolated nuclei in a buffer without Mg++ (i.e., a technique often employed to prepare the nuclear matrix or scaffold) cannot be considered an optimal procedure to maintain the original distribution of protein within the nucleus.

Local distribution of odor responsivities of mouse olfactory receptor neurons

The local distribution of odor responsivity was studied in isolated mouse olfactory neurons retaining their original spatial relationships in intact tissue. The selectivity for three odorants and population of responsive cells were estimated from the odor-induced increase in cytoplasmic calcium. It was found that cells with different odor selectivities coexisted with a shorter distance than cells of the same type. Cells with a similar odor responsivity were arranged somewhat more densely than a complete random distribution. The results indicated the coexistence of different subtypes of odor responsive cells in the septal epithelium with sparse clustering of similarly responsive cells.

Simultaneous recording of [Ca 2+] i increases in isolated olfactory receptor neurons retaining their original spatial relationship in intact tissue

A new method is described for isolating olfactory receptor neurons suitable for simultaneous recording of odorant responses in several cells. This method, called “tissue printing” by Cassab and Varner, was used to isolate cells for measurement of odorant-induced increases in cytosolic-free calcium concentration ([Ca 2+] i) using the Ca 2+ indicator dye fura-2. A large number of receptors could be isolated from a piece of olfactory epithelium (about 300 μm square), preserving their normal morphology and relative local topology to that in the intact olfactory tissue. The probability that there are one or more receptor cells with odorant-induced responses in [Ca 2+] i per preparation was 4 times higher with cells isolated by the tissue printing than with those obtained by the pipetting method. The responses of 2 receptor cells separated by 28 μm in the recording chamber differed for 2 odorants: isoamyl acetate and citralva. The method was useful for isolating receptor neurons without losing their morphological features and for investigating the spatial distribution of odorant responsiveness of each receptor over the olfactory epithelium.

Full-view rainbow-reflection holograms

A simple method of recording full-view rainbow-reflection holograms on a single flat plate is described: only one white-light illuminating source is required in the reconstruction process. The hologram can be viewed from opposite sides, where each side of a three-dimensional object, with its original spatial relationship, is displayed in bright colours.

Simple Full-View Rainbow Holograms

A simple technique is described by which holograms can be made on a single flat plate which, when illuminated with white light, reconstruct very bright images of the front and back of a three-dimensional object. An observer can view the hologram from opposite sides and see both sides of the object imaged in their original spatial relationship.