Comparison of Adult Female and Male PMHS Pelvis and Lumbar Response to Underbody Blast.

The goal of this study was to gather and compare kinematic response and injury data on both female and male whole-body Post-mortem Human Surrogates (PMHS) responses to Underbody Blast (UBB) loading. Midsized males (50th percentile, MM) have historically been most used in biomechanical testing and were the focus of the Warrior Injury Assessment Manikin (WIAMan) program, thus this population subgroup was selected to be the baseline for female comparison. Both small female (5th percentile, SF) and large female (75th percentile, LF) PMHS were included in the test series to attempt to discern whether differences between male and female responses were predominantly driven by sex or size.

A comparison of fracture response in female and male lumbar spine in simulated under body blast component tests.

Underbody blasts (UBB) from mines and improvised explosive devices in military combat can cause debilitating spine injuries to vehicle mounted soldiers. Due to the exclusion of females in combat roles in prior US Department of Defense policy, UBB exposure and injury have predominantly affected male soldiers. Recent policy changes have opened many combat roles to women serving in the US Military (Carter, 2015) and have increased the need to understand the injury potential for female Warfighters.

Return to Play after Posterior Cruciate Ligament Injuries.

Purpose Of Review: Posterior cruciate ligament injuries can be treated conservatively with a structured rehabilitation program or with surgical reconstruction. Treatment algorithms are based on a variety of factors including the patient's presentation, physical exam, and desired level of activity. The goal is to return the patient to their athletic pursuits with a stable and pain-free knee.

Spatial and temporal dynamics of HDACs class IIa following mild traumatic brain injury in adult rats.

The fundamental role of epigenetic regulatory mechanisms involved in neuroplasticity and adaptive responses to traumatic brain injury (TBI) is gaining increased recognition. TBI-induced neurodegeneration is associated with several changes in the expression-activity of various epigenetic regulatory enzymes, including histone deacetylases (HDACs). In this study, PET/CT with 6-([F]trifluoroacetamido)-1- hexanoicanilide ([F]TFAHA) to image spatial and temporal dynamics of HDACs class IIa expression-activity in brains of adult rats subjected to a weight drop model of diffuse, non-penetrating, mild traumatic brain injury (mTBI).

Whole Body PMHS Response in Injurious Experimental Accelerative Loading Events.

Previous studies involving whole-body post-mortem human surrogates (PHMS) have generated biomechanical response specifications for physically simulated accelerative loading intended to reproduce seat and floor velocity histories occurring in under-body blast (UBB) events (e.g.,.

Dynamic Response of the Thoracolumbar and Sacral Spine to Simulated Underbody Blast Loading in Whole Body Post Mortem Human Subject Tests.

Fourteen simulated underbody blast impact sled tests were performed using a horizontal deceleration sled with the aim of evaluating the dynamic response of the spine in under various conditions. Conditions were characterized by input (peak velocity and time-to-peak velocity for the seat and floor), seat type (rigid or padded) and the presence of personnel protective equipment (PPE). A 50% (T12) and 30% (T8) reduction in the thoracic spine response for the specimens outfitted with PPE was observed.

Optimization of Underbody Blast Energy-Attenuating Seat Mechanisms Using Modified MADYMO Human Body Models.

Though energy attenuating (EA) seats for air and spacecraft applications have existed for decades, they have not yet been fully characterized for their energy attenuation capability or resulting effect on occupant protection in vertical underbody blast. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant's pelvis and lower spine. Using dynamic rigid-body modeling, a virtual tool to determine optimal force and deflection limits was developed to reduce pelvis and lower spine injuries in underbody blast events using a generic seat model.

Mechanisms and timing of injury to the thoracic, lumbar and sacral spine in simulated underbody blast PMHS impact tests.

During an underbody blast (UBB) event, mounted occupants are exposed to high rate loading of the spine via the pelvis. The objective of this study was to simulate UBB loading conditions and examine mechanisms of injury in the thoracic, lumbar and sacral spine. Fourteen instrumented, whole-body, postmortem human subject (PMHS) experiments were performed using the WSU-decelerative horizontal sled system.

Response Ratio Development for Lateral Pendulum Impact with Porcine Thorax and Abdomen Surrogate Equivalents.

There has been recent progress over the past 10 years in research comparing 6-year-old thoracic and abdominal response of pediatric volunteers, pediatric post mortem human subjects (PMHS), animal surrogates, and 6-year-old ATDs. Although progress has been made to guide scaling laws of adult to pediatric thorax and abdomen data for use in ATD design and development of finite element models, further effort is needed, particularly with respect to lateral impacts. The objective of the current study was to use the impact response data of age equivalent swine from Yaek et al.

Investigate the Variations of the Head and Brain Response in a Rodent Head Impact Acceleration Model by Finite Element Modeling.

Diffuse axonal injury (DAI) is a severe form of traumatic brain injury and often induced by blunt trauma. The closed head impact acceleration (IA) model is the most widely used rodent DAI model. However, this model results in large variations of injury severity.

The Ice, Cloud, and Land Elevation Satellite - 2 Mission: A Global Geolocated Photon Product Derived From the Advanced Topographic Laser Altimeter System.

The Ice, Cloud, and land Elevation Satellite - 2 (ICESat-2) observatory was launched on 15 September 2018 to measure ice sheet and glacier elevation change, sea ice freeboard, and enable the determination of the heights of Earth's forests. ICESat-2's laser altimeter, the Advanced Topographic Laser Altimeter System (ATLAS) uses green (532 nm) laser light and single-photon sensitive detection to measure time of flight and subsequently surface height along each of its six beams. In this paper, we describe the major components of ATLAS, including the transmitter, the receiver and the components of the timing system.

Side Impact Assessment and Comparison of Appropriate Size and Age Equivalent Porcine Surrogates to Scaled Human Side Impact Response Biofidelity Corridors.

Analysis and validation of current scaling relationships and existing response corridors using animal surrogate test data is valuable, and may lead to the development of new or improved scaling relationships. For this reason, lateral pendulum impact testing of appropriate size cadaveric porcine surrogates of human 3-year-old, 6-year-old, 10-year-old, and 50 percentile male age equivalence, were performed at the thorax and abdomen body regions to compare swine test data to already established human lateral impact response corridors scaled from the 50 percentile human adult male to the pediatric level to establish viability of current scaling laws. Appropriate Porcine Surrogate Equivalents PSE for the human 3-year-old, 6-year-old, 10-year-old, and 50 percentile male, based on whole body mass, were established.

Time course of blast-induced injury in the rat auditory cortex.

Blast exposure is an increasingly significant health hazard and can have a range of debilitating effects, including auditory dysfunction and traumatic brain injury. To assist in the development of effective treatments, a greater understanding of the mechanisms of blast-induced auditory damage and dysfunction, especially in the central nervous system, is critical. To elucidate this area, we subjected rats to a unilateral blast exposure at 22 psi, measured their auditory brainstem responses (ABRs), and histologically processed their brains at 1 day, 1 month, and 3-month survival time points.

A novel fabrication method of carbon electrodes using 3D printing and chemical modification process.

Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes.

Mechanical strain to maxillary incisors during direct laryngoscopy.

Background: While most Direct laryngoscopy leads to dental injury in 25-39% of cases. Dental injury occurs when the forces and impacts applied to the teeth exceed the ability of the structures to dissipate energy and stress. The purpose of this study was to measure strain, (which is the change produced in the length of the tooth by a force applied to the tooth) strain rate, and strain-time integral to the maxillary incisors and determine if they varied by experience, type of blade, or use of an alcohol protective pad (APP).

An Experimental and Numerical Study of Hybrid III Dummy Response to Simulated Underbody Blast Impacts.

Anthropometric test devices (ATDs) such as the Hybrid III dummy have been widely used in automotive crash tests to evaluate the risks of injury at different body regions. In recent years, researchers have started using automotive ATDs to study the high-speed vertical loading response caused by underbody blast impacts. This study analyzed the Hybrid III dummy responses to short-duration, large magnitude vertical accelerations in a laboratory setup.

ACL Rehabilitation Progression: Where Are We Now?

Purpose Of Review: With the increase of publications available to the rehabilitation specialist, there is a need to identify a progression to safely progress the patient through their post-operative ACL reconstruction rehabilitation program. Rehabilitation after ACL reconstruction should follow an evidence-based functional progression with graded increase in difficulty in activities.

Recent Findings: Clinicians should be discouraged not to use strict time frames and protocols when treating patients following ACL reconstruction.

Neuronal Injury and Glial Changes Are Hallmarks of Open Field Blast Exposure in Swine Frontal Lobe.

With the rapid increase in the number of blast induced traumatic brain injuries and associated neuropsychological consequences in veterans returning from the operations in Iraq and Afghanistan, the need to better understand the neuropathological sequelae following exposure to an open field blast exposure is still critical. Although a large body of experimental studies have attempted to address these pathological changes using shock tube models of blast injury, studies directed at understanding changes in a gyrencephalic brain exposed to a true open field blast are limited and thus forms the focus of this study. Anesthetized, male Yucatan swine were subjected to forward facing medium blast overpressure (peak side on overpressure 224-332 kPa; n = 7) or high blast overpressure (peak side on overpressure 350-403 kPa; n = 5) by detonating 3.

Quantitative electroencephalography in a swine model of blast-induced brain injury.

Objective: Electroencephalography (EEG) was used to examine brain activity abnormalities earlier after blast exposure using a swine model to develop a qEEG data analysis protocol.

Methods: Anaesthetized swine were exposed to 420-450 Kpa blast overpressure and survived for 3 days after blast. EEG recordings were performed at 15 minutes before the blast and 15 minutes, 30 minutes, 2 hours and 1, 2 and 3 days post-blast using surface recording electrodes and a Biopac 4-channel data acquisition system.

Biomechanical Responses of the Brain in Swine Subject to Free-Field Blasts.

Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed .

The whole genome sequence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reveals insights into the biology and adaptive evolution of a highly invasive pest species.

Background: The Mediterranean fruit fly (medfly), Ceratitis capitata, is a major destructive insect pest due to its broad host range, which includes hundreds of fruits and vegetables. It exhibits a unique ability to invade and adapt to ecological niches throughout tropical and subtropical regions of the world, though medfly infestations have been prevented and controlled by the sterile insect technique (SIT) as part of integrated pest management programs (IPMs). The genetic analysis and manipulation of medfly has been subject to intensive study in an effort to improve SIT efficacy and other aspects of IPM control.