A Simplified Crossing Fiber Model in Diffusion Weighted Imaging

Diffusion MRI (dMRI) is a vital source of imaging data for identifying anatomical connections in the living human brain that form the substrate for information transfer between brain regions. dMRI can thus play a central role toward our understanding of brain function. The quantitative modeling and analysis of dMRI data deduces the features of neural fibers at the voxel level, such as direction and density. The modeling methods that have been developed range from deterministic to probabilistic approaches. Currently, the Ball-and-Stick model serves as a widely implemented probabilistic approach in the tractography toolbox of the popular FSL software package and FreeSurfer/TRACULA software package. However, estimation of the features of neural fibers is complex under the scenario of two crossing neural fibers, which occurs in a sizeable proportion of voxels within the brain. A Bayesian non-linear regression is adopted, comprised of a mixture of multiple non-linear components. Such models can pose a difficult statistical estimation problem computationally. To make the approach of Ball-and-Stick model more feasible and accurate, we propose a simplified version of Ball-and-Stick model that reduces parameter space dimensionality. This simplified model is vastly more efficient in the terms of computation time required in estimating parameters pertaining to two crossing neural fibers through Bayesian simulation approaches. Moreover, the performance of this new model is comparable or better in terms of bias and estimation variance as compared to existing models

The effect of military clothing on gunshot wound patterns in a cadaveric animal limb model

The majority of injuries in survivors of gunshot wounds (GSW) are typically to the extremities. Novel wound ballistic research is encouraged to try and capture corporate knowledge on the management of these injuries gained during recent conflicts and understand the wounding patterns seen. With recent work examining the effect of UK military clothing on extremity GSW patterns in a synthetic model, a model with greater biofidelity is needed for ballistic testing. The aim of this study was to assess the effect of UK military clothing on GSW patterns within a cadaveric animal limb model using two types of ammunition commonly used in recent conflicts—7.62 × 39 mm and 5.45 × 39 mm. In total, 24 fallow deer hind limbs were shot, 12 by 7.62 mm projectiles and the remaining 12 shot by 5.45 mm projectiles, further divided into four with no clothing layers (Cnil), four with a single clothing layer (Cmin) and four with maximum clothing layers (Cmax) as worn on active duty by UK military personnel. Limbs were analysed after ballistic impact using contrast CT scanning to obtain measurements of permanent cavity damage, and results were compared using analysis of variance (ANOVA). Results showed significantly different damage measurements within limbs with Cmax for both ammunition types compared with the other clothing states. This may result in GSWs that require more extensive surgical management, and invites further study

Preliminary effect of projectile yaw on extremity gunshot wounding in a cadaveric animal model: a serendipitous study

Gunshot wounding (GSW) is capable of causing devastating tissue injuries by delivering kinetic energy (KE) through the contact surface area of a projectile. The contact surface area can be increased by yaw, deformation and fragmentation, all of which may be caused by any intermediate layers struck by the projectile prior to entering its target. This study aims to describe whether projectile yaw occurring before penetration of a cadaveric animal limb model causes greater damage with or without clothing layers present using 5.45 × 39 mm projectiles. In total, 12 fallow deer hind limbs were shot, further divided into 4 with no clothing layers (Cnil), 4 with a single clothing layer (Cmin) and 4 with maximum clothing layers (Cmax) as worn on active duty by UK military personnel. Contrast computed tomography (CT) of limbs was used to measure permanent cavity size and the results were compared using analysis of variance (ANOVA). No significant differences were found among clothing states for each series of measurements taken, with greater cavity sizes noted in all clothing states. This is in contrast to previous work looking at symmetrically flying projectiles in the same model, where a larger permanent cavity was found only with Cmax present. Projectile yaw is therefore likely to be a key variable with regard to causation of damage within this extremity wound model

Criminal Procedure and Criminal Law: Virginia Supreme Court Decisions During the 70\u27s

The purpose of this note is to examine the decisions of the Virginia Supreme Court during the period between 1970-1980 in the area of criminal procedure and substantive criminal law. Legislative changes will not be dealt with in depth except as they have affected these decisions. Because of space constraints, a complete review of all areas is impossible; therefore, review has been limited to those issues most likely to be of interest to the practicing attorney. The discussion will also attempt to establish the position of the Virginia Supreme Court on these matters in relation to the United States Supreme Court and the majority of state courts

Ballistic research techniques: visualizing gunshot wounding patterns

There are difficulties associated with mapping gunshot wound (GSW) patterns within opaque models. Depending on the damage measurement parameters required, there are multiple techniques that can provide methods of “seeing” the GSW pattern within an opaque model. The aim of this paper was to test several of these techniques within a cadaveric animal limb model to determine the most effective. The techniques of interest were flash X-ray, ultrasound, physical dissection, and computed-tomography (CT). Fallow deer hind limbs were chosen for the model with four limbs used for each technique tested. Quarantined 7.62 × 39 mm ammunition was used for each shot, and each limb was only shot once, on an outdoor range with shots impacting at muzzle velocity. Flash X-ray provided evidence of yaw within the limb during the projectile’s flight; ultrasound though able to visualise the GSW track, was too subjective and was abandoned; dissection proved too unreliable due to the tissue being cadaveric so also too subjective; and lastly, CT with contrast provided excellent imaging in multiple viewing planes and 3D image reconstruction; this allowed versatile measurement of the GSW pattern to collect dimensions of damage as required. Of the different techniques examined in this study, CT with contrast proved the most effective to allow precise GSW pattern analysis within a cadaveric animal limb model. These findings may be beneficial to others wishing to undertake further ballistic study both within clinical and forensic fields

Neuronal pathways in tendon healing and tendinopathy : update

The regulatory mechanisms involved in tendon homeostasis and repair are not fully understood. Accumulating data, however, demonstrate that the nervous system, in addition to afferent (sensory) functions, through efferent neuronal pathways plays an active role in regulating pain, inflammation, and tissue repair processes. Thus, in normal-, healing- and tendinopathic tendons three major neuronal signalling pathways consisting of autonomic, sensory and glutamatergic neuromediators have been established. In healthy tendons, these neural elements are found in the paratenon, whereas the proper tendon is practically devoid of nerves, reflecting that normal tendon homeostasis is regulated by pro- and anti-inflammatory mediators from the tendon surroundings. During tendon repair, however, there is extensive nerve ingrowth into the tendon proper and subsequent time-dependent appearance of sensory, autonomic and glutamatergic mediators, which amplify and fine-tune inflammation and tendon regeneration. In tendinopathy, excessive and protracted sensory and glutamatergic signalling may be involved in inflammatory, painful and hypertrophic tissue reactions. As our understanding of these processes improves, neuronal mediators may prove to be useful in the development of targeted pharmacotherapy and tissue engineering approaches to painful, degenerative and traumatic tendon disorders.Swedish Research Council (project nr. 2012-3510)Stockholm County Council and Karolinska Institutet (project nr. SLL20100168)Swedish National Centre for Sports ResearchCOREF-Sweden grantAlberta Innovates Health Solutions OA Team GrantAccepte

“Thanks for hearing me out”: Voices of social work students during COVID-19

As social work educators and students, the COVID-19 pandemic impacted our teaching and learning in challenging ways. We embarked on a qualitative research study to better understand the ways in which the pandemic was affecting the social work students in our program. Three faculty mentors worked collaboratively with five social work students across BSW, MSW, and PhD programs to interview 66 BSW and MSW students about their experiences, challenges, and hopes during the early months of the pandemic. BSW and MSW students led the analysis and early dissemination for the project. This essay describes the unique experiences of social work students by using a research poem to capture the emotional and experiential aspects of the students we interviewed

A Simplified Crossing Fiber Model in Diffusion Weighted Imaging

Diffusion MRI (dMRI) is a vital source of imaging data for identifying anatomical connections in the living human brain that form the substrate for information transfer between brain regions. dMRI can thus play a central role toward our understanding of brain function. The quantitative modeling and analysis of dMRI data deduces the features of neural fibers at the voxel level, such as direction and density. The modeling methods that have been developed range from deterministic to probabilistic approaches. Currently, the Ball-and-Stick model serves as a widely implemented probabilistic approach in the tractography toolbox of the popular FSL software package and FreeSurfer/TRACULA software package. However, estimation of the features of neural fibers is complex under the scenario of two crossing neural fibers, which occurs in a sizeable proportion of voxels within the brain. A Bayesian non-linear regression is adopted, comprised of a mixture of multiple non-linear components. Such models can pose a difficult statistical estimation problem computationally. To make the approach of Ball-and-Stick model more feasible and accurate, we propose a simplified version of Ball-and-Stick model that reduces parameter space dimensionality. This simplified model is vastly more efficient in the terms of computation time required in estimating parameters pertaining to two crossing neural fibers through Bayesian simulation approaches. Moreover, the performance of this new model is comparable or better in terms of bias and estimation variance as compared to existing models

Increasing age and tear size reduce rotator cuff repair healing rate at 1 year : Data from a large randomized controlled trial

Peer reviewedPublisher PD

Evaluation methods for vaccination campaigns on college campuses: a scoping review

Background: Vaccinations are successful, cost-effective tools to prevent the spread of certain infectious diseases. Many colleges conduct vaccination campaigns on their campuses for various vaccinepreventable diseases, including measles, mumps, influenza, HPV, and most recently, for SARS-CoV-2, the virus responsible for COVID-19. Implementing these campaigns requires substantial effort and understanding their effectiveness is an important factor in justifying these programs. Aim: This scoping review aims to identify, review, and summarize existing evaluation methods for vaccination campaigns on college campuses in order to provide evaluation guidance for institutions planning future vaccination campaigns.Methods: Publications that focused on vaccination campaigns on college campuses for students and/or faculty and staff and described their evaluation methods were included in our analysis. A systematic search of the literature identified 2,101 articles. After duplicates were removed, titles and abstracts were screened, and references searched, 43 articles were identified for full-text review. Sixteen articles provided evaluation information and were systematically reviewed. Results: Interventions targeted a variety of vaccine-preventable diseases, with the majority either aiming to increase HPV vaccine uptake or vaccinate against meningococcal serogroups. Most studies reported on campaigns that included both educational activities and provided vaccinations. Evaluation methods varied widely. Some studies measured vaccine-related knowledge and attitudes. Vaccine uptake was most commonly measured as a simple count of doses administered. Conclusions: College campus vaccination campaigns are evaluated in multiple ways, with little consistency inhowthe effectiveness of campaigns are measured. There is a need to develop clear evaluation methods for college vaccination programs, especially how to calculate vaccination rates associated with these efforts