Selected annotated instance segmentation sub-volumes from a large scale CT data-set of a historic aircraft.

The Me 163 was a Second World War fighter airplane and is currently displayed in the Deutsches Museum in Munich, Germany. A complete computed tomography (CT) scan was obtained using a large scale industrial CT scanner to gain insights into its history, design, and state of preservation. The CT data enables visual examination of the airplane's structural details across multiple scales, from the entire fuselage to individual sprockets and rivets. However, further processing requires instance segmentation of the CT data-set. Currently, there are no adequate computer-assisted tools for automated or semi-automated segmentation of such large scale CT airplane data. As a first step, an interactive data annotation process has been established. So far, seven 512 × 512 × 512 voxel sub-volumes of the Me 163 airplane have been annotated, which can potentially be used for various applications in digital heritage, non-destructive testing, or machine learning. This work describes the data acquisition process, outlines the interactive segmentation and post-processing, and discusses the challenges associated with interpreting and handling the annotated data.

Intra verses extra familial sexual abuse in the Orthodox Jewish community as reported by mental health professionals.

OBJECTIVE: While the prevalence rates of sexual abuse (SA) in the Orthodox Jewish (OJ) community appear to be similar to that of the general population, community insularity has made it difficult to obtain more detailed information about the context of SA occurring. The aim of this study was to gather more detailed information regarding the occurrence of SA within the OJ community. METHOD: Mental health professionals were asked to complete an anonymous survey about each client in their current caseload who were raised as OJ and disclosed a history of SA. The survey gathered basic demographic information including gender, age of abuse onset, and the relationship the perpetrator had with their victim. Respondents also answered a qualitative question describing the nature of the abuse that took place. RESULTS: 143 mental health professionals provided information on 248 survivors of SA. For females, the majority of the abuse was intrafamilial (68%) while for males the majority of the abuse was extrafamilial (63%). Females were most likely to be abused by their brother (28.7%) whereas males were most likely to be abused by a friend or neighbor (31.7%). For females, the majority (58%) of abuse started before the age of nine. The qualitative themes that emerged highlight the severe nature of most of the abuse occurring. CONCLUSIONS: This study highlights the need for more age-appropriate education in the OJ community regarding SA as well as programming aimed at targeting intrafamilial SA. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Struggles in the Orthodox Jewish shidduch dating system-A large-scale qualitative analysis.

Marriage is an important life goal and is highly valued among Orthodox Jews. Shidduch dating refers to the arranged dating system that is typically used within the community. Previous research and anecdotal evidence suggest that the shidduch system has become difficult and challenging for many individuals, yet there is a dearth of evidence on the subject. This study set out to explore issues related to dating and marriage within the Orthodox Jewish community using a large sample size. Participants included 889 Orthodox individuals across diverse demographic groups who responded to an optional question within a larger survey inquiring about their thoughts and experiences on the subject. An inductive qualitative analysis was conducted, and this paper focuses on the seven most prevalent themes that emerged. These themes include issues related to superficial criteria in mate selection, gender segregation, perceived surplus of females, pressure to marry before feeling ready, the formal structure of shidduch dating, the exclusion of specific groups from the process and lack of education in areas of intimacy and sexuality. This study is important in promoting clinical awareness regarding the struggles that many Orthodox Jewish daters face and underscores the need for communal change addressing these issues.

High-Energy Computed Tomography as a Prospective Tool for In Situ Monitoring of Mass Transfer Processes inside High-Pressure Reactors-A Case Study on Ammonothermal Bulk Crystal Growth of Nitrides including GaN.

For the fundamental understanding and the technological development of the ammonothermal method for the synthesis and crystal growth of nitrides, an in situ monitoring technique for tracking mass transport of the nitride throughout the entire autoclave volume is desirable. The feasibility of using high-energy computed tomography for this purpose was therefore evaluated using ex situ measurements. Acceleration voltages of 600 kV were estimated to yield suitable transparency in a lab-scale ammonothermal setup for GaN crystal growth designed for up to 300 MPa operating pressure. The total scan duration was estimated to be in the order of 20 to 40 min, which was sufficient given the comparatively slow crystal growth speed in ammonothermal growth. Even shorter scan durations or, alternatively, lower acceleration voltages for improved contrast or reduced X-ray shielding requirements, were estimated to be feasible in the case of ammonoacidic growth, as the lower pressure requirements for this process variant allow for thinned autoclave walls in an adapted setup designed for improved X-ray transparency. Promising nickel-base and cobalt-base alloys for applications in ammonothermal reactors with reduced X-ray absorption in relation to the maximum operating pressure were identified. The applicability for the validation of numerical simulations of the growth process of GaN, in addition to the applicability of the technique to further nitride materials, as well as larger reactors and bulk crystals, were evaluated.

Self-endorsed history of abuse and wellbeing in a community sample of Jewish Orthodox single individuals.

OBJECTIVE: The current study explored the prevalence rates of physical, sexual, and emotional abuse as well as the relationship between abuse and mental health within the Jewish Orthodox nonmarried community. METHOD: To reduce response bias, abuse and mental health measures were added to a larger survey that was being conducted in the area of dating. Participants responded to an abuse question and completed the Center for Epidemiological Studies Depression Scale (CESD-10), the Generalized Anxiety Disorder 7-item Scale (GAD-7), and the Satisfaction with Life Scale (SWLS). RESULTS: Of the 274 respondents, 29.2% endorsed emotional abuse, 13.5% endorsed sexual abuse, and 9.2% endorsed physical abuse. Participants that endorsed overall abuse scored significantly higher on the depression and anxiety inventories and significantly lower on the life satisfaction inventory compared with those that did not endorse abuse. CONCLUSION: This study is helpful in garnering communal and clinical awareness regarding abuse prevalence and mental health risks among this insular population where those abused are at times shunned. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Review of high energy x-ray computed tomography for non-destructive dimensional metrology of large metallic advanced manufactured components.

Advanced manufacturing technologies, led by additive manufacturing, have undergone significant growth in recent years. These technologies enable engineers to design parts with reduced weight while maintaining structural and functional integrity. In particular, metal additive manufacturing parts are increasingly used in application areas such as aerospace, where a failure of a mission-critical part can have dire safety consequences. Therefore, the quality of these components is extremely important. A critical aspect of quality control is dimensional evaluation, where measurements provide quantitative results that are traceable to the standard unit of length, the metre. Dimensional measurements allow designers, manufacturers and users to check product conformity against engineering drawings and enable the same quality standard to be used across the supply chain nationally and internationally. However, there is a lack of development of measurement techniques that provide non-destructive dimensional measurements beyond common non-destructive evaluation focused on defect detection. X-ray computed tomography (XCT) technology has great potential to be used as a non-destructive dimensional evaluation technology. However, technology development is behind the demand and growth for advanced manufactured parts. Both the size and the value of advanced manufactured parts have grown significantly in recent years, leading to new requirements of dimensional measurement technologies. This paper is a cross-disciplinary review of state-of-the-art non-destructive dimensional measuring techniques relevant to advanced manufacturing of metallic parts at larger length scales, especially the use of high energy XCT with source energy of greater than 400 kV to address the need in measuring large advanced manufactured parts. Technologies considered as potential high energy x-ray generators include both conventional x-ray tubes, linear accelerators, and alternative technologies such as inverse Compton scattering sources, synchrotron sources and laser-driven plasma sources. Their technology advances and challenges are elaborated on. The paper also outlines the development of XCT for dimensional metrology and future needs.

Migrating Shear Bands in Shaken Granular Matter.

When dense granular matter is sheared, the strain is often localized in shear bands. After some initial transient these shear bands become stationary. Here, we introduce a setup that periodically creates horizontally aligned shear bands which then migrate upward through the sample. Using x-ray radiography we demonstrate that this effect is caused by dilatancy, the reduction in volume fraction occurring in sheared dense granular media. Further on, we argue that these migrating shear bands are responsible for the previously reported periodic inflating and collapsing of the material.

Comparison of Achievable Contrast Features in Computed Tomography Observing the Growth of a 4H-SiC Bulk Crystal.

Today the physical vapor transport process is regularly applied for the growth of bulk SiC crystals. Due to the required high temperature of up to 2400 °C, and low gas pressure of several Mbar inside the crucible, the systems are encapsulated by several layers for heating, cooling and isolation inhibiting the operator from observing the growth. Also, the crucible itself is fully encapsulated to avoid impurities from being inserted into the crystal or disturbing the temperature field distribution. Thus, once the crucible has been set up with SiC powder and the seed crystal, the visible access to the progress of growth is limited. In the past, X-ray radiography has allowed this limitation to be overcome by placing the crucible in between an X-ray source and a radiographic film. Recently these two-dimensional attenuation signals have been extended to three-dimensional density distribution by the technique of computed tomography (CT). Beside the classic X-ray attenuation signal dominated by photoelectric effect, Compton effect and Rayleigh scattering, X-ray diffraction resulting in the crystalline structure of the 4H-SiC superimposes the reconstructed result. In this contribution, the achievable material contrast related to the level of X-ray energy and the absorption effects is analyzed using different CT systems with energies from 125 kV to 9 MeV. Furthermore the X-ray diffraction influence is shown by the comparison between the advanced helical-CT method and the classical 3D-CT.

Influence of Morphological Changes in a Source Material on the Growth Interface of 4h-Sic Single Crystals.

In this study, the change of mass distribution in a source material is tracked using an in situ computer tomography (CT) setup during the bulk growth of 4H- silicon carbide (SiC) via physical vapor depostion (PVT). The changing properties of the source material due to recrystallization and densification are evaluated. Laser flash measurement showed that the thermal properties of different regions of the source material change significantly before and after the growth run. The Si-depleted area at the bottom of the crucible is thermally insulating, while the residual SiC source showed increased thermal conductivity compared to the initially charged powder. Ex situ CT measurements revealed a needle-like structure with elongated pores causing anisotropic behavior for the heat conductivity. Models to assess the thermal conductivity are applied in order to calculate the changes in the temperature field in the crucible and the changes in growth kinetics are discussed.

3D Imaging and Quantitative Analysis of Vascular Networks: A Comparison of Ultramicroscopy and Micro-Computed Tomography.

RATIONALE: Classic histology is the gold standard for vascular network imaging and analysis. The method however is laborious and prone to artefacts. Here, the suitability of ultramicroscopy (UM) and micro-computed tomography (CT) was studied to establish potential alternatives to histology. METHODS: The vasculature of murine organs (kidney, heart and atherosclerotic carotid arteries) was visualized using conventional 2D microscopy, 3D light sheet ultramicroscopy (UM) and micro-CT. Moreover, spheroid-based human endothelial cell vessel formation in mice was quantified. Fluorescently labeled Isolectin GS-IB4 A647 was used for in vivo labeling of vasculature for UM analysis, and analyses were performed ex vivo after sample preparation. For CT imaging, animals were perfused postmortem with radiopaque contrast agent. RESULTS: Using UM imaging, 3D vascular network information could be obtained in samples of animals receiving in vivo injection of the fluorescently labeled Isolectin GS-IB4. Resolution was sufficient to measure single endothelial cell integration into capillaries in the spheroid-based matrigel plug assay. Because of the selective staining of the endothelium, imaging of larger vessels yielded less favorable results. Using micro-CT or even nano-CT, imaging of capillaries was impossible due to insufficient X-ray absorption and thus insufficient signal-to-noise ratio. Identification of lumen in murine arteries using micro-CT was in contrast superior to UM. CONCLUSION: UM and micro-CT are two complementary techniques. Whereas UM is ideal for imaging and especially quantifying capillary networks and arterioles, larger vascular structures are easier and faster to quantify and visualize using micro-CT. 3D information of both techniques is superior to 2D histology. UM and micro-CT together may open a new field of clinical pathology diagnosis.

Surgical anatomy and accuracy of percutaneous achilles tendon lengthening.

BACKGROUND: Percutaneous Achilles tendon lengthening is frequently done to treat gastrocsoleus equinus contracture. To our knowledge, no study has documented the proximity of tendinous or neurovascular structures to the nearest edges of each hemisection in a percutaneous Achilles tendon lengthening, the complication rates related to injury of such structures, or the Achilles tendon rupture rates from inaccurate cuts. Thus, our goal was to document these distances and determine the accuracy of this procedure. METHODS: We performed triple-hemisection percutaneous Achilles tendon lengthening (Hoke technique) in 15 cadaver specimens and documented the distance from each cut edge to various relevant anatomical structures. We also documented the accuracy of each cut (diameter of hemisection divided by total tendon diameter), with a reference goal of 50% transection at each level. RESULTS: We found that percutaneous Achilles tendon lengthening is a relatively accurate procedure with hemisections averaging 50% for the middle cut and 60% at the most proximal cut, and 55% at the distal cut. Some tendinous and neurovascular structures are, on average, less than 1 cm from the nearest margin of a given hemisection and are, therefore, at risk. These included the flexor hallucis longus at the middle and proximal cuts (9.1 mm and 5.7 mm, respectively), the tibial nerve at the proximal cut (8.3 mm), and the sural nerve at the middle-lateral cut (7.9 mm). CONCLUSION: In cadavers, reasonably accurate cuts can be made, with some vital structures less than 1 cm from the cut tendon.

Epidemiology of ankle arthritis: report of a consecutive series of 639 patients from a tertiary orthopaedic center.

The purpose of our study was to identify the cause of symptomatic ankle arthritis in a consecutive series of patients presenting in a tertiary care setting. Between 1991 and 2004, 639 patients with Kellgren grade 3 or 4 ankle arthritis presented to the University of Iowa Orthopaedic Foot and Ankle Surgery service. The cause of the arthritis was determined based on medical history, physical examination, and imaging studies. To get a sense of the relative prevalence of the etiologies of lower extremity arthritis in our setting, we evaluated the cause of arthritis of all new patients presenting to the University of Iowa Orthopaedic Department from 1999-2004 with arthritis of the ankle, to those with arthritis of the hip or knee during one year. Of the 639 arthritic ankles, 445 (70%) were post-traumatic, 76 (12%) were rheumatoid disease and 46 (7%) were idiopathic (primary osteoarthritis). The post-traumatic ankle arthritis patients were most commonly associated with past rotational ankle fractures. The majority of ankle arthritis is associated with previous trauma, whereas the primary cause of knee or hip arthritis is idiopathic. Unique strategies to prevent or treat post-traumatic ankle arthritis are needed.

The effects of BMP-7 in a rat posterolateral intertransverse process fusion model.

The use of autologous bone grafting is an essential component in spine fusion because it is the key factor in achieving long-term stable arthrodesis between spinal motion segments. However, harvesting autologous iliac crest bone graft can be associated with significant morbidity and its supply is limited. Although no current substitute for autologous graft is available, multiple studies have already established the success of bone morphogenetic proteins (BMPs) in augmenting spinal fusion in models using larger animals. The purpose of our study was to evaluate the ability of BMP to augment a posterolateral intertransverse process single-level fusion in a rat. To our knowledge, this model has not been used to evaluate the effects of recombinant BMPs. A posterolateral intertransverse process fusion was attempted in white male Sprague-Dawley rats. The following are the four study groups: insoluble collagen bone matrix (ICBM) alone, 3 microg BMP-7 + 25 mg ICBM, 10 microg BMP-7 + 25 mg ICBM, and a sham group with no implanted material. The animals were killed on postoperative day 21 and were evaluated for signs of clinical and/or radiographic fusion. All of the rats in the 10 microg BMP-7 + 25 mg ICBM group demonstrated clinical fusion and had solid bilateral fusion masses on radiographs. None of the rats in the sham group, ICBM group, or 3 microg BMP-7 + 25 mg ICBM group fused clinically; however, the rats in the 3 microg BMP-7 + 25 mg ICBM group did show evidence of new bone formation. Our study demonstrates that a rat posterolateral intertransverse process fusion model is inexpensive and efficient and produces consistent results. It also shows that BMP can augment fusion in a rat and that dosing plays a role in successful fusion. This is consistent with results that have been studied in larger animal models.