Injury Tolerance Research Articles

Antioxidant enzymatic changes in bell pepper fruit associated with chilling injury tolerance induced by hot water.

Green bell pepper is highly susceptible to low temperature. The activation of the enzymatic antioxidant system plays a determining role in tolerance to chilling injury (CI). Immersion in hot water for short time previous to storage at low temperature induces tolerance to this disorder. However, there is a lack of information about the induction of chilling tolerance in bell pepper by hot water and its relationship with the enzymatic antioxidant system. We evaluated the effect of three immersion times (T, 1-, 2-, 3-min) in hot water (HW, 53°C) on the reduction of CI in bell pepper and its relationship with the enzymatic antioxidant system during storage at 5°C and 21°C. The use of hot water for 1-, 2- or 3-min reduced the decay and CI indexes, maintained quality parameters, ascorbic acid, and total phenolics content. The storage at 5°C by itself activated the enzymatic antioxidant system. The use of HWT 1-, 2-, and 3-min helped to increase this effect, especially by HWT2 . PRACTICAL APPLICATIONS: The application of a treatment with hot water for short times in fruit sensitive to chilling injury is undoubtedly a viable alternative to increase their tolerance and commercialization. In this study, the application of a hot water treatment for 1-, 2- or 3-min in bell pepper reduced the deterioration and susceptibility to chilling injury and stimulated the enzymatic antioxidant system. In this sense, agricultural producers can take advantage of this treatment to prolong the storage period of the fruit maintaining its quality and improving its commercialization.

Rearward-Facing Infant Child Restraint Systems with Support Legs in Frontal and Frontal-Oblique Impacts.

Previous studies of support legs in rearward-facing infant CRS models have focused on frontal impacts and have found that the presence of a support leg is associated with a reduction in head injury metrics. However, real-world crashes often involve an oblique principal direction of force. The current study used sled tests to evaluate the effectiveness of support legs in rearward-facing infant CRS models for frontal and frontal-oblique impacts with and without a simulated front row seatback. Frontal and frontal-oblique impact sled tests were conducted using the simulated Consumer Reports test method with and without the blocker plate, which was developed to represent a front row seatback. The Q1.5 anthropomorphic test device (ATD) was seated in rearward-facing infant CRS models, which were tested with and without support legs. The presence of a support leg was associated with significant reductions of head injury metrics below injury tolerance limits for all tests, which supports the findings of previous studies. The presence of a support leg was also associated with significant reductions of peak neck tensile force. The presence of the blocker plate resulted in greater head injury metrics compared to tests without the blocker plate, but the result was non-significant. However, the fidelity of the interaction between the CRS and blocker plate as an adequate representation of the interaction that would occur in a real vehicle is not well understood. The findings from the current study continue to support the benefit of support legs in managing the energy of impact for a child in a rearward-facing CRS.

Analysis of Foot-Ankle-Leg Injuries in Various Under-Foot Impact Loading Environments With a Human Active Lower Limb Model.

Lower limb injuries caused by under-foot impacts often appear in sport landing, automobile collision, and antivehicular landmine blasts. The purpose of this study was to evaluate a foot-ankle-leg model of the human active lower limb (HALL) model, and used it to investigate lower leg injury responses in different under-foot loading environments to provide a theoretical basis for the design of physical dummies adapted to multiple loading conditions. The model was first validated in allowable rotation loading conditions, like dorsiflexion, inversion/eversion, and external rotation. Then, its sensitivity to loading rates and initial postures was further verified through experimental data concerning both biomechanical stiffness and injury locations. Finally, the model was used to investigate the biomechanical responses of the foot-ankle-leg region in different under-foot loading conditions covering the loading rate from sport landing to blast impact. The results showed that from -rovide a theoreticaln to 30 deg dorsiflexion, the neutral posture always showed the largest tolerance, and more than 1.5 times tolerance gap was achieved between neutral posture and dorsiflexion 30 deg. Under-foot impacts from 2 m/s to 14 m/s, the peak tibia force increased at least 1.9 times in all postures. Thus, we consider that it is necessary to include initial posture and loading rate factors in the definition of the foot-ankle-leg injury tolerance for under-foot impact loading.

Development and multi-level validation of a computational model to predict traumatic aortic injury.

Traumatic aortic injury (TAI) is one of the leading causes of fatalities in blunt impact. However, there is no consensus on the injury mechanism of TAI in traffic accidents, mainly due to the complexity of occurrence scenarios and limited real-world crash data relevant to TAI. In this study, a computational model of the aorta with nonlinear mechanical characteristics and accurate morphology was developed and integrated within a thorax finite element model that included all major anatomical structures. To maximize the model's capability for predicting TAI, a multi-level process was presented to validate the model comprehensively. At the component level, the in vitro aortic pressurization testing was simulated to mimic the aortic burst pressure. Then, a sled test of a truncated cadaver was modeled to evaluate aorta response under posterior acceleration. The frontal chest pendulum impact was utilized to validate the performance of the aorta within full body model under direct chest compression. A parametric study was implemented to determine an injury tolerance for the aorta under these different loading conditions. The simulated peak pressure before aortic rupture was within the range of the experimental burst pressure. For the sled test, the simulated chest deflection and cross-sectional pressure of the aorta were correlated with the experimental measurement. No aorta injury was observed in simulated results of both sled test and chest pendulum impact, which matched the experimental findings. The present model will be a useful tool for understanding the TAI mechanisms, evaluating injury tolerance, and developing prevention strategies for aortic injuries.

Stretchable microchannel-on-a-chip: A simple model for evaluating the effects of uniaxial strain on neuronal injury

BackgroundAxonal injury is a major component of traumatic spinal cord injury (SCI), associated with rapid deformation of spinal tissue and axonal projections. In vitro models enable us to examine these effects and screen potential therapies in a controlled, reproducible manner. New methodA customized, stretchable microchannel system was developed using polydimethylsiloxane microchannels. Cortical and spinal embryonic rat neurons were cultured within the microchannel structures, allowing a uniaxial strain to be applied to isolated axonal processes. Global strains of up to 52% were applied to the stretchable microchannel-on-a-chip platform leading to local strains of up to 12% being experienced by axons isolated in the microchannels. ResultsIndividual axons exposed to local strains between 3.2% and 8.7% developed beading within 30-minutes of injury. At higher local strains of 9.8% and 12% individual axons ruptured within 30-minutes of injury. Axon bundles, or fascicles, were more resistant to rupture at each strain level, compared to individual axons. At lower local strain of 3.2%, axon bundles inside microchannels and neuronal cells near entrances of them progressively swelled and degenerated over a period of 7 days after injury. Comparison with existing method(s)This method is simple, reliable and reproducible with good control and measurement of injury tolerance and morphological deformations using standard laboratory equipment. By measuring local strains, we observed that axonal injuries occur at a lower strain magnitude and a lower strain rate than previous methods reporting global strains, which may not accurately reflect the true axonal strain. ConclusionsWe describe a novel stretchable microchannel-on-a-chip platform to study the effect of varying local strain on morphological characteristics of neuronal injury.

The Head AIS 4+ Injury Thresholds for the Elderly Vulnerable Road User Based on Detailed Accident Reconstructions.

Compared with the young, the elderly (age greater than or equal to 60 years old) vulnerable road users (VRUs) face a greater risk of injury or death in a traffic accident. A contributing vulnerability is the aging processes that affect their brain structure. The purpose of this study was to investigate the injury mechanisms and establish head AIS 4+ injury tolerances for the elderly VRUs based on various head injury criteria. A total of 30 elderly VRUs accidents with detailed injury records and video information were selected and the VRUs’ kinematics and head injuries were reconstructed by combining a multi-body system model (PC-Crash and MADYMO) and the THUMS (Ver. 4.0.2) FE models. Four head kinematic-based injury predictors (linear acceleration, angular velocity, angular acceleration, and head injury criteria) and three brain tissue injury criteria (coup pressure, maximum principal strain, and cumulative strain damage measure) were studied. The correlation between injury predictors and injury risk was developed using logistical regression models for each criterion. The results show that the calculated thresholds for head injury for the kinematic criteria were lower than those reported in previous literature studies. For the brain tissue level criteria, the thresholds calculated in this study were generally similar to those of previous studies except for the coup pressure. The models had higher (>0.8) area under curve values for receiver operator characteristics, indicating good predictive power. This study could provide additional support for understanding brain injury thresholds in elderly people.

Gut Microbiome Composition and Serum Metabolome Profile Among Individuals With Spinal Cord Injury and Normal Glucose Tolerance or Prediabetes/Type 2 Diabetes

ObjectiveTo compare the gut microbiome composition and serum metabolome profile among individuals with spinal cord injury (SCI) and normal glucose tolerance (NGT) or prediabetes/type 2 diabetes (preDM/T2D). DesignCross-sectional design. SettingResearch university. ParticipantsA total of 25 adults (N=25) with SCI were included in the analysis and categorized as NGT (n=16) or preDM/T2D (n=9) based on their glucose concentration at minute 120 during a 75-g oral glucose tolerance test. The American Diabetes Association diagnosis guideline was used for grouping participants. InterventionsNot applicable. Main Outcome MeasuresA stool sample was collected and used to assess the gut microbiome composition (alpha and beta diversity, microbial abundance) via the 16s ribosomal RNA sequencing technique. A fasting serum sample was used for liquid chromatography–mass spectrometry–based untargeted metabolomics analysis, the results from which reflect the relative quantity of metabolites detected and identified. Gut microbiome and metabolomics data were analyzed by the Quantitative Insights into Microbial Ecology 2 and Metaboanalyst platforms, respectively. ResultsGut microbiome alpha diversity (Pielou's evenness index, Shannon's index) and beta diversity (weighted UniFrac distances) differed between groups. Compared with participants with NGT, participants with preDM/T2D had less evenness in microbial communities. In particular, those with preDM/T2D had a lower abundance of the Clostridiales order and higher abundance of the Akkermansia genus, as well as higher serum levels of gut-derived metabolites, including indoxyl sulfate and phenylacetylglutamine (P < .05 for all). ConclusionsOur results provide evidence for altered gut microbiome composition and dysregulation of gut-derived metabolites in participants with SCI and preDM/T2D. Both indoxyl sulfate and phenylacetylglutamine have been implicated in the development of cardiovascular diseases in the able-bodied population. These findings may inform future investigations in the field of SCI and cardiometabolic health.

Assessment of tolerance and resistance of inbred rice cultivars to combined infestations of rice water weevil and stemborers

AbstractPlants possess defense‐related traits that both reduce injury from herbivores (resistance) and the amount of yield loss per unit injury (tolerance). Plant resistance and tolerance can be utilized in pest management programs. The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is the most destructive early‐season pest of rice (Oryza sativa L., Poaceae) in the USA. Additionally, lepidopteran stemborers, particularly the invasive Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), are increasing in economic importance as pests of rice in Louisiana, USA. This study was conducted to evaluate both the resistance and tolerance of commonly grown inbred rice cultivars in Louisiana to combined infestations of rice water weevils and stemborers. Field experiments were established at the Rice Research Station in Crowley, LA, USA from 2017 to 2019. Eight commonly grown inbred cultivars were selected and pest infestation levels were manipulated using insecticidal seed treatments. The rice cultivar ‘Jupiter’ supported the highest numbers of immature rice water weevils, whereas weevil densities on other cultivars were intermediate. Low levels of stemborer injury were observed in ‘Cheniere’ and ‘Jazzman‐2’, which suggests that these cultivars express some resistance to stemborers, whereas high stemborer injury was observed in ‘Cocodrie, ‘CL151’, and ‘Mermentau’. Together, rice water weevil and stemborer infestations negatively affected rice yields, with losses up to 18%. However, differences among cultivars in overall yield losses were minimal. Comparisons of slopes of yield × weevil density relationships among cultivars revealed a greater decline, that is, yield loss per weevil, for Cheniere relative to Cocodrie. Our data suggest that plant resistance can serve as a valuable component of an integrated pest management program, particularly for stemborers.

Host plant and humidity effects on phytoseiid mite, Gynaeseius liturivorus (Acari: Phytoseiidae) egg hatchability.

Gynaeseius liturivorus (Ehara) (Acari: Phytoseiidae) is a promising biological control agent for tiny arthropod pests, including Thrips tabaci Lindeman (Thysanoptera: Thripidae) known as a major pest of Welsh onion. In fields during summer, G. liturivorus is observed on soybean, but not on Welsh onion, even when numerous T. tabaci are present. To elucidate G. liturivorus's occurrence on soybean and Welsh onion in relation to relative humidity (RH), we examined its egg hatching on their seedlings under low RH conditions. Then we estimated the moisture transpiration from both plants. Egg hatching occurred only on soybean plants exhibiting greater moisture transpiration. Aiming at utilizing G. liturivorus as a biological control agent for Welsh onion production in summer, evaluation of its relative tolerance and compensation potential for drought injury is necessary. Therefore, we used five phytoseiid species including G. liturivorus and Neoseiulus californicus to estimate the RH and vapor pressure deficit (VPD) at which 50% of eggs hatch (RH50 and VPD50). Furthermore, we examined G. liturivorus and N. californicus egg hatching under different RH oscillation conditions. Results show G. liturivorus as the most drought-sensitive among the five species tested, but G. liturivorus isable to compensate for lethal low-RH effects on egg hatching in part by periodic exposure to high RH conditions, as observed for N. californicus.

Endogenous melatonin generation plays a positive role in chilling tolerance in relation to redox homeostasis in litchi fruit during refrigeration

The potent role of endogenous melatonin (MEL) in affecting chilling injury (CI) and related chilling tolerance regulatory mechanisms in harvested litchi fruit during refrigeration at 4 °C were investigated in this study. In the first experiment, exogenous MEL exposure exerted an inhibitory impact on the development of CI severity in refrigerated litchi fruit, as indicated by the lower CI index and delayed red color loss of pericarp, whereas treatment with p-chlorophenylalanine (p-CPA), an inhibitor of MEL biosynthesis, aggravated the degree of CI. The suppression of CI afforded by exogenous MEL was abated under the combined application of exogenous MEL and p-CPA. In the second experiment, the effects of p-CPA alone treatment on changes in biochemical parameters during refrigeration were analyzed. The results showed that p-CPA down-regulated the expressions of MEL biosynthesis genes, including LcTDC, LcT5H and LcSNAT, contributing to reduced generation of endogenous serotonin and MEL. p-CPA treatment accelerated oxidative stress-triggered membrane deterioration, as reflected by increases in relative leakage rate (RLR), reactive oxygen species (ROS) production, lipoxygenase (LOX) activity and malondialdehyde (MDA) accumulation. The membrane damage caused by p-CPA further resulted in loss of subcellular compartmentalization and enzymatic oxidation, as demonstrated by increased activities of polyphenol oxidase (PPO) and peroxidase (POD) in parallel with reduced contents of total phenolics and anthocyanin. Compared with control fruit, lower activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR), were observed in fruit receiving p-CPA. Additionally, p-CPA suppressed the expression levels of genes encoding oxidized protein repair-related enzymes, including LcMsrA1, LcMsrA2, LcMsrB1 and LcMsB2. These results suggest that endogenous MEL might confer a protective role against chilling stress by modulating cellular redox status in harvested litchi fruit during refrigeration.

Evaluation of Rotation Reduction Features in Infant and Extended-Use Convertible Child Restraint Systems during Frontal and Rear Impacts.

A correctly used child restraint system (CRS) is associated with a substantial reduction of injury and mortality risks in motor vehicle crashes and epidemiologic data suggests that toddlers are provided greater protection when restrained in a rearward-facing CRS compared to a forward-facing CRS. Some 'extended-use' European CRS models can accommodate children up to six years rearward-facing and have a support (load) leg and/or a pair of lower (Swedish) tethers to reduce rotation during frontal and rear impacts, respectively. Laboratory studies have found that a support leg reduces head and neck injury metrics of anthropomorphic test devices (ATDs) younger than three years in rearward-facing CRS models during frontal impacts. The objectives of the current study were to perform sled tests to: (1) evaluate the effects of using a support leg in rearward-facing infant and extended-use convertible CRS models during frontal impacts, (2) evaluate the effects of using a pair of lower tethers in a rearward-facing extended-use convertible CRS model during rear impacts and (3) compare responses of ATDs in an extendeduse convertible CRS with a support leg and a pair of lower tethers in rearward- and forward-facing configurations during frontal and rear impacts. The presence of a support leg in rearward-facing infant and extended-use convertible CRS models in frontal impacts was associated with reductions in head injury metrics across a range of pediatric ATDs and neck injury metrics were below injury tolerance values. Other strategies in the design of rearward-facing CRS and front row vehicle seatbacks may be available to further reduce head injury metrics. Lower tethers reduced the rearward rotation of an extended-use convertible CRS toward the vehicle seatback in rear impacts and were typically associated with reductions in head and neck injury metrics for the Q6 ATD, but not the Q3 ATD. For frontal impacts, neck injury metrics were typically greater for ATDs in the forward-facing extended-use convertible CRS, whereas head injury metrics were typically greater for the rearward-facing condition (with a support leg and a pair of lower tethers). Interactions of the ATD head and/or the rearward-facing extended-use convertible CRS with the blocker plate in rearward-facing frontal impacts need to be further investigated.

Sex Difference in the Tolerance of Hepatic Ischemia-reperfusion Injury and Hepatic Estrogen Receptor Expression According to Age and Macrosteatosis in Healthy Living Liver Donors.

Hepatic estrogen signaling, which is important in liver injury/recovery, is determined by the level of systemic estrogen and hepatic estrogen receptor. We aimed to evaluate whether females' advantage in the tolerance of hepatic ischemia-reperfusion injury decreases according to the age of 40 y (systemic estrogen decrease) and macrosteatosis (hepatic estrogen receptor decrease). We included 358 living liver donors (128 female and 230 male individuals). The tolerance of hepatic ischemia-reperfusion injury was determined by the slope of the linear regression line modeling the relationship between the duration of intraoperative hepatic ischemia and the peak postoperative transaminase level. Estrogen receptor content was measured in the biopsied liver samples using immunohistochemistry. In the whole cohort, the regression slope for aspartate transaminase was comparable between female and male individuals (P = 0.940). Within the subgroup of donors aged ≤40 y, the regression slope was significantly smaller in female individuals (P = 0.031), whereas it was comparable within donors aged >40 y (P = 0.867). Within the subgroup of nonmacrosteatotic donors aged ≤40 y, the regression slope was significantly smaller in female individuals in univariable (P = 0.002) and multivariable analysis (P = 0.006), whereas the sex difference was not found within macrosteatotic donors aged ≤40 y (P = 0.685). Estrogen receptor content was significantly greater in female individuals within nonmacrosteatotic donors aged ≤40 y (P = 0.021), whereas it was not different in others of age >40 y or with macrosteatosis (P = 0.450). The tolerance of hepatic ischemia-reperfusion injury was greater in female individuals than in male individuals only when they were <40 y and without macrosteatosis. The results were in agreement with the hepatic estrogen receptor immunohistochemistry study.

Experimental and Numerical Measurement of the Impact Strength of Poly-lactic Acid through a Low-velocity Impact

This paper presents the results obtained through experimental work and numerical simulation of the kinetic energy dissipation of lactic acid after application of the impact load. The experimental tests were performed according to ASTM standards using the motion drop arrow test. It has been designed according to the standard ASTMD7136.The specimens were plates completely constrained with two edges by the clamping fixture. Two energy absorption parameters (namely saturation impact energy and damage degree), and two relevant characteristic values of the impact force history (namely the first damage force and the maximum force) were included. The impact energy of 2.4 J was measured by the difference in the thickness mode. The finite element method was used by FE symbol (Abaqus/Explicit Dynamic) implemented by a User Defined Sub routine (VUMAT). The results showed areas of shock injury and sample tolerance, and there was a match between the experimental and numerical results. Diagrams are presented to show the history of relevant kinematical, dynamic and energetic quantities, both to synthesize the dependency of the energy parameters and force threshold values on the impact velocity. This study will help to measure the absorbed and kinetic energy of polymers, thus, it will help define the properties of polymers used in critical applications such as medicine.

Development of a detailed human neck finite element model and injury risk curves under lateral impact

Advanced neck finite element modeling and development of neck injury criteria are important for the design of optimal neck protection systems in automotive and other environments. They are also important in virtual tests. The objectives of the present study were to develop a detailed finite element model (FEM) of the human neck and couple it to the existing head model, validate the model with kinematic data from legacy human volunteer and human cadaver impact datasets, and derive lateral impact neck injury risk curves using survival analysis from the upper and lower neck forces and moments. The detailed model represented the anatomy of a young adult mid-size male. It included all the cervical and first thoracic vertebrae, intervening discs, upper and lower spinal ligaments, bilateral facet joints, and passive musculature. Material properties were obtained from literature. Frontal, oblique, and lateral impacts to the distal end of the model was applied based on human volunteer and human cadaver experimental data. Corridor and cross-correlation methods were used for validation. The CORrelation and Analysis (CORA) score was used for objective assessments. Forces and moments were obtained at the occipital condyles (OC) and T1, and parametric survival analysis was used to derive injury risk curves to define human neck injury tolerance to lateral impact. The Brier Score Metric (BSM) was used to determine the hierarchical sequence among the injury metrics. The CORA scores for the lateral, frontal, and oblique impact loading conditions were 0.80, 0.91, and 0.87, respectively, for human volunteer data, and the mean score was 0.7 for human cadaver lateral impacts. Injury risk curves along with ±95% confidence intervals are given for all the four biomechanical metrics. The OC shear force was the optimal metric based on the BSM. A force of 1.5 kN was associated with the 50% probability level of AIS3+ neck injury. As a first step, the presented risk curves serve as human tolerance criteria under lateral impact, hitherto not available in published literatures, and they can be used in virtual testing and advancing restraint systems for improving human safety.

Cardiac injury in rats with experimental posttraumatic stress disorder and mechanisms of its limitation in experimental posttraumatic stress disorder-resistant rats.

Traumatic stress causes posttraumatic stress disorder (PTSD). PTSD is associated with cardiovascular diseases and risk of sudden cardiac death in some subjects. We compared effects of predator stress (PS, cat urine scent, 10 days) on mechanisms of cardiac injury and protection in experimental PTSD-vulnerable (PTSD) and -resistant (PTSDr) rats. Fourteen days post-stress, rats were evaluated with an elevated plus-maze test, and assigned to PTSD and PTSDr groups according to an anxiety index calculated from the test results. Cardiac injury was evaluated by: 1) exercise tolerance; 2) ECG; 3) myocardial histomorphology; 4) oxidative stress; 5) pro- and anti-inflammatory cytokines. Myocardial heat shock protein 70 (HSP70) was also measured. Experimental PTSD developed in 40% of rats exposed to PS. Exercise tolerance of PTSD rats was 25% less than control rats and 21% less than PTSDr rats. ECG QRS, QT, and OTc intervals were significantly longer in PTSD rats than in control and PTSDr rats. Only cardiomyocytes of PTSD rats had histomorphological signs of metabolic and hypoxic injury and impaired contractility. Oxidative stress markers were higher in PTSD than in PTSDr rats. Pro-inflammatory IL-6 was higher in PTSD rats than in control and PTSDr rats, and anti-inflammatory IL-4 was lower in PTSD than in control and PTSDr rats. Myocardial HSP70 was lower in PTSD rats than in PTSDr and control rats. Our conclusion was that rats with PTSD developed multiple signs of cardiac injury. PTSDr rats were resistant also to cardiac injury. Factors that limit cardiac damage in PS rats include reduced inflammation and oxidative stress and increased protective HSP70.NEW & NOTEWORTHY For the first time, rats exposed to stress were segregated into experimental PTSD (ePTSD)-susceptible and ePTSD-resistant rats. Cardiac injury, ECG changes, and impaired exercise tolerance were more pronounced in ePTSD-susceptible rats. Resistance to ePTSD was associated with decreased inflammation and oxidative stress and with increased protective heat shock protein 70. Results may help identify individuals at high risk of PTSD and also provide a foundation for developing preventive and therapeutic means to restrict PTSD-associated cardiac morbidity.

Determinants of effective action on workplace safety and health in global companies — The case of global network container terminal operators

Container terminals are critical nodes in the globalisation of trade. Many are operated by global companies with strong corporate rhetoric espousing zero tolerance of injury and ill-health. Yet operational practices often contribute to the intensification of work and outsourcing of labour; conditions associated with poor safety and health. Serious and fatal injuries and ill-health continue to occur in these terminals. With reference to the findings of a study of occupational safety and health (OSH) arrangements in terminals operated by four of the largest operators, key contextual determinants in the terminals’ labour relations and regulatory environments that influence practice and outcomes are identified. The influences are compared in different national settings and, the paper finds, like multinational companies generally, global operators are obliged to adapt and reflect local contexts. In relation to OSH best practice, a critical influence is the way that local context acts to constrain and challenge business logics and interests. This acts to make 'best practice' more likely where companies are constrained in this way, regardless of the claims of their corporate rhetoric.

A Review of On-Field Investigations into the Biomechanics of Concussion in Football and Translation to Head Injury Mitigation Strategies.

This review paper summarizes the scientific advancements in the field of concussion biomechanics in American football throughout the past five decades. The focus is on-field biomechanical data collection, and the translation of that data to injury metrics and helmet evaluation. On-field data has been collected with video analysis for laboratory reconstructions or wearable head impact sensors. Concussion biomechanics have been studied across all levels of play, from youth to professional, which has allowed for comparison of head impact exposure and injury tolerance between different age groups. In general, head impact exposure and injury tolerance increase with increasing age. Average values for concussive head impact kinematics are lower for youth players in both linear and rotational acceleration. Head impact data from concussive and non-concussive events have been used to develop injury metrics and risk functions for use in protective equipment evaluation. These risk functions have been used to evaluate helmet performance for each level of play, showing substantial differences in the ability of different helmet models to reduce concussionrisk. New advances in head impact sensor technology allow for biomechanical measurements in helmeted and non-helmeted sports for a more complete understanding of concussion tolerance in different demographics. These sensors along with advances in finite element modeling will lead to a better understanding of the mechanisms of injury and human tolerance to head impact.

Effect of Ethylene-Insensitive Mutation etr2b on Postharvest Chilling Injury in Zucchini Fruit

Zucchini is a vegetable fruit that is very susceptible to postharvest chilling injury, and fruit ethylene production is correlated with chilling injury sensitivity, such that the more tolerant the cultivar, the lower is its ethylene production. It is expected that zucchini fruit with reduced sensitivity to ethylene would have a higher chilling injury tolerance. In this study, we compared the postharvest fruit quality of wild type and ethylene-insensitive mutant etr2b, in which a mutation was identified in the coding region of the ethylene receptor gene CpETR2B. Flowers from homozygous WT (wt/wt), mutant plants in homozygous (etr2b/etr2b) and heterozygous (wt/etr2b) were hand-pollinated, and all fruits were harvested with the same length, at about 8 days after pollination. After harvesting, fruit of each genotype was randomly divided in 3 batches of 12 fruits each (four replications with three fruits each), and then stored at 4 °C and 95% RH. At 0, 7, and 14 days after cold storage, each batch was used to assess ethylene production, respiration rate, weight and firmness loss, chilling injury, and oxidative stress metabolites. The results showed a lower chilling injury associated with lower cold-induced ethylene production in the mutant fruit, in comparison with the WT fruit. These data demonstrated that the ethylene-insensitive etr2b mutant fruit was more tolerant to chilling injury, confirming that basal ethylene in the still undamaged fruit could function as a modulator of post-harvest chilling injury. Moreover, the higher chilling tolerance of the etr2b mutant fruit was not associated with MDA content, but was concomitant with a reduction in the accumulation of hydrogen peroxide in the refrigerated mutant fruit.

Sensitivity of scale factor choice on injury response for equal-stress equal-velocity scaling

Objective This study aims to evaluate the assumption of geometric similitude inherent to equal-stress equal-velocity scaling by determining if scale factors created with different anthropometry metrics result in different scaled injury tolerance predictions. This assumption will be evaluated when equal-stress equal-velocity scaling is employed across dissimilar (e.g., 50th male to small female) and similar (e.g., small female to a reference small female anthropometry) anthropometries. Methods Three average male and three small female lower extremity specimens that were tested in ankle inversion/eversion were selected for scaling analysis. Three additional female specimens were selected as a reference dataset, such that the accuracy of the scaled data could be compared to an independent measured dataset. The failure moments, total height and total weight for these donors were determined from literature. Additional anthropometry metrics (leg length, calcaneus height, and bimalleolar width) were taken from each of their respective CT scans. Scale factors were calculated from these previously determined anthropometric metrics for the six donors selected for scaling analysis by targeting the averaged anthropometry metrics of the reference small female dataset. Equal-stress equal-velocity scaling was applied to the failure moments from literature using different scale factors. The mean predicted failure tolerance and standard deviation for scaled data using different scale factors were compared to one another and to the mean failure tolerance from the reference (unscaled) small female dataset. Results When using average male data to predict ankle failure moment for a small female anthropometry, scaled moments were statistically significantly different from measured small female failure moment. Furthermore, scaled failure moments predicted using scale factors based on different anthropometry metrics were found to be significantly different from one another. Conversely, predicted mean failure moment using scaled female data of a similar size to the reference data was not significantly different from measured female failure moment, and the predicted failure moments were not significantly affected by choice of scale factor. Conclusions This study shows that an injury metric predicted with equal-stress equal-velocity scaling is sensitive to choice of scale factor when employing scaling across occupants of dissimilar size and sex. This conclusion suggests error can be introduced into scaled response due to choice of anthropometry metric used to create a scale factor, and therefore, anthropometry metrics used to create scale factors should be justified mechanistically and shown to apply across size and sex before being employed.

RNA-seq reveals molecular mechanisms behind chilling injury tolerance in ISW-treated zucchini fruit during cold storage

RNA-seq reveals molecular mechanisms behind chilling injury tolerance in ISW-treated zucchini fruit during cold storage