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Structural Neuroimaging of Anorexia Nervosa: Future Directions in the Quest for Mechanisms Underlying Dynamic Alterations.
Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation and extreme weight loss. Pseudoatrophic brain changes are often readily visible in individual brain scans, and AN may be a valuable model disorder to study structural neuroplasticity. Structural magnetic resonance imaging studies have found reduced gray matter volume and cortical thinning in acutely underweight patients to normalize following successful treatment. However, some well-controlled studies have found regionally greater gray matter and persistence of structural alterations following long-term recovery. Findings from diffusion tensor imaging studies of white matter integrity and connectivity are also inconsistent. Furthermore, despite the severity of AN, the number of existing structural neuroimaging studies is still relatively low, and our knowledge of the underlying cellular and molecular mechanisms for macrostructural brain changes is rudimentary. We critically review the current state of structural neuroimaging in AN and discuss the potential neurobiological basis of structural brain alterations in the disorder, highlighting impediments to progress, recent developments, and promising future directions. In particular, we argue for the utility of more standardized data collection, adopting a connectomics approach to understanding brain network architecture, employing advanced magnetic resonance imaging methods that quantify biomarkers of brain tissue microstructure, integrating data from multiple imaging modalities, strategic longitudinal observation during weight restoration, and large-scale data pooling. Our overarching objective is to motivate carefully controlled research of brain structure in eating disorders, which will ultimately help predict therapeutic response and improve treatment
Cloning of a Carcinoembryonic Antigen Gene Family Member Expressed in Leukocytes of Chronic Myeloid Leukemia Patients and Bone Marrow
The carcinoembryonic antigen (CEA) gene family belongs to the immunoglobulin superfamily and can be subdivided into the CEA and pregnancy-specific glycoprotein subgroups. The basic structure of the encoded proteins consists of, in addition to a leader, one IgV-like and 2, 3, or 6 IgC-like domains. These domains are followed by varying COOH-terminal regions responsible for secretion, transmembrane anchoring, or insertion into the membrane by a glycosyl phosphatidylinositol tail. Here we report on the characterization of CGM6, a new member of the CEA gene subgroup, by complementary DNA cloning. The deduced coding region comprises 349 amino acids and consists of a leader, one IgV-like, two IgC-like domains, and a hydrophobic region, which is replaced by a glycosyl phosphatidylinositol moiety in the mature protein. CGM6 transcripts were only found thus far in leukocytes of chronic myeloid leukemia patients, in normal bone marrow, and in marginal amounts in normal granulocytes. The CGM6 gene product might, therefore, represent a myeloid marker. Analyses of CGM6 protein-expressing HeLa transfectants with monoclonal antibodies strongly indicate that the CGM6 gene codes for the CEA family member NCA-95
Sensitivity Analysis of the Ultrasonic Response from a Non-Normal Surface-Breaking Crack
The use of computer simulations is becoming an increasing popular strategy for designing ultrasonic inspections. There are many benefits of accurate simulations, the most important one being their cost effectiveness. In many cases, before inspection procedures are finalized, it is possible to simulate the competing inspection plans, and to use the outputs of simulation trials to choose the best plan. This strategy is particularly useful when there is limited accessibility to the components that need to be inspected, as in the extreme case when the inspection procedure requires that operating equipment be removed from service. In such cases, it is best to be fully prepared before taking the inspection equipment to the test site and computer simulations can play an important role in such preparation, often at a significantly reduced cost with respect to traditional methods
Biology and management of American woodcock in Missouri (2017)
GuideThe American woodcock (Scolopax minor) is a migratory game bird that inhabits much of the central and eastern United States. It belongs to the shorebird family, but unlike other species such as the sandpiper and common snipe, woodcock have adapted to a mixture of habitats in upland locations, including woodlands and young forests with early stages of plant regrowth, also referred to as early successional vegetation. Although few woodcock nest in Missouri, the state is an important migration corridor, providing habitat for birds traveling between wintering and breeding areas farther north. Understanding woodcock migration is a conservation priority, as mortality can be high during this time. Therefore, habitats that provide food and cover along the migratory route are crucial to their survival. This guide provides information on woodcock biology, their life cycle and habitat needs, as well as an overview of management techniques that landowners and managers can use to improve habitats for woodcock on their property
Seismic Evaluation of Highway Bridges - Phase 1
The primary objective of the study was to establish the guidelines for screening, assessing, and ranking Indiana bridges for seismic upgrade. The outcome of the study is a complete strategy for the detailed structural assessment of Indiana highway bridges subjected to seismic forces. The structural evaluation is conducted using a nonlinear time-history analysis of the bridge for simulated or actual records. The specific soil conditions at the site are accounted in terms of the ground motion. From the time history analysis the maximum structural response including displacements, bending moments, shear and axial forces are computed. A weighted evaluation of the ratio of expected demand to available capacity is conducted next. A seismic rating is established based on the weighted evaluation. The bridges are classified into three different categories: high, moderate and low seismic risk. In the case of bridges falling in the high and moderate categories, the weighted seismic rating can be used to establish strengthening needs. The same type of analysis could be used to evaluate different strengthening schemes. In the case where the bridge inventory is substantial, the proposed strategy in this study would be more effective helped by a preliminary first level screening of the bridge population. Several first level screening procedures available in the United States are evaluated in this study. First level screening procedures are used in the qualitative ranking of seismic bridges with respect to seismic risk. They are simplified methods for use in extensive highway networks and are the first steps in a comprehensive evaluation strategy. The Indiana Department of Transportation has conducted a preliminary first level screening of the bridge population in the southern part of the state. Several bridges have been identified as presenting a high level of seismic risk. The approach proposed in this study could be used to further refine the preliminary ranking, and to evaluate different strengthening schemes. It must be pointed out that the soil-structure interaction of bridge structures is a developing area. Many questions remain to be answered regarding the proper modeling of the foundation and the surrounding soil. The proposed evaluation strategy can be improved by means of a field evaluation of dynamic characteristics of a representative sample of bridge foundations and soil conditions in the critical southern part of the state
Anisotropic Gauss-Hermite Beam Model Applied to through-Transmission Inspections of Delaminations in Composite Plates
Manufactured parts containing composite materials can present challenging ultrasonic inspection problems. The inherent anisotropy of such materials acts to distort propagating ultrasonic beams, leading in turn to an associated distortion of defect images. Such distortions complicate the task of estimating the physical dimensions of a defect from its ultrasonic image. In the present work we demonstrate how these difficulties can be overcome by appropriately modelling the ultrasonic inspection process, and using the model to analyze defect images. To illustrate the approach, we consider a normal incidence through-transmission inspection of a flat uniaxial composite plate with an internal delamination. We begin by reviewing our model of the inspection process which incorporates the Gauss-Hermite model for beam propagation in anisotropic materials. The inspection model requires as inputs certain parameters which characterize the transducers, and others which characterize the composite material. We demonstrate how these parameters can be obtained from simple beam-mapping experiments. We then present experimental C-scan images of a seeded circular delamination in a composite plate, and compare these to images predicted by the model. Finally, we demonstrate how the model can be used to accurately size a delamination from its ultrasonic image
Ultrasonic NDE Techniques for Integrally Fabricated Rotors
Solid-state bonding methods, e.g., diffusion bonding and pressure welding, are becoming common manufacture and repair techniques for gas turbine engine components. Effective NDE inspection techniques are crucial to the utilization of this approach due to the high stresses on the bond plane associated with jet engine operation. Recently we have examined ultrasonic techniques for assessing bond quality including leaky Rayleigh waves and critical angle longitudinal waves[1], for which the illuminating waves are nearly normal to the bond plane, and longitudinal waves at near grazing incidence to the bond[1]. Based upon preliminary theoretical analyses[1,2] of ultrasonic reflectivity from imperfect interfaces, it was found that the reflection coefficient for both longitudinal and shear waves increases to unity as the incident angle approaches grazing[1]. In contrast, the bond reflection coefficients for near normal incidence can be quite small, depending upon the degree of imperfection of the bond. A second drawback to the first two approaches mentioned is that surface roughness of the blade can cause scattering noise which dominates the signals reflected from the bond. The grazing incidence technique suffers less from these problems since the probe is oriented nearly normal to the surface of the blade and the interaction of the beam with the surface is minimized
Dosimetric validation of SmART-RAD Monte Carlo modelling for x-ray cabinet radiobiology irradiators
Objective: Accuracy and reproducibility in the measurement of radiation dose and associated reporting are critically important for the validity of basic and preclinical radiobiological studies performed with kilovolt x-ray radiation cabinets. This is essential not only to enable results of radiobiological studies to be repeated, as well as enable valid comparisons between laboratories. In addition, the commonly used single point dose value hides the 3D dose heterogeneity across the irradiated sample. This is particularly true for preclinical rodent models, and is generally difficult to measure directly. Radiation transport simulations integrated in an easy to use application could help researchers improve quality of dosimetry and reporting.
Approach: this paper describes the use and dosimetric validation of a newly-developed Monte Carlo (MC) tool, SmART-RAD, to simulate the x-ray field in a range of standard commercial x-ray cabinet irradiators used for preclinical irradiations. Comparisons are made between simulated and experimentally determined dose distributions for a range of configurations to assess the potential use of this tool in determining dose distributions through samples, based on more readily available air-kerma calibration point measurements.
Main results: simulations gave very good dosimetric agreement with measured depth dose distributions in phantoms containing both water and bone equivalent materials. Good spatial and dosimetric agreement between simulated and measured dose distributions was obtained when using beam-shaping shielding.
Significance: the MC simulations provided by SmART-RAD provide a useful tool to go from a limited number of dosimetry measurements to detailed 3D dose distributions through a non-homogeneous irradiated sample. This is particularly important when trying to determine the dose distribution in more complex geometries. The use of such a tool can improve reproducibility and dosimetry reporting in preclinical radiobiological research
Impaired Spatial Reorientation in the 3xTg-AD Mouse Model of Alzheimer's Disease.
In early Alzheimer's disease (AD) spatial navigation is impaired; however, the precise cause of this impairment is unclear. Recent evidence suggests that getting lost is one of the first impairments to emerge in AD. It is possible that getting lost represents a failure to use distal cues to get oriented in space. Therefore, we set out to look for impaired use of distal cues for spatial orientation in a mouse model of amyloidosis (3xTg-AD). To do this, we trained mice to shuttle to the end of a track and back to an enclosed start box to receive a water reward. Then, mice were trained to stop in an unmarked reward zone to receive a brain stimulation reward. The time required to remain in the zone for a reward was increased across training, and the track was positioned in a random start location for each trial. We found that 6-month female, but not 3-month female, 6-month male, or 12-month male, 3xTg-AD mice were impaired. 6-month male and female mice had only intracellular pathology and male mice had less pathology, particularly in the dorsal hippocampus. Thus, AD may cause spatial disorientation as a result of impaired use of landmarks
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