Review of Witnessing Australian Stories: History, Testimony and Memory in Contemporary Culture, by Kelly Jean Butler

Review of Witnessing Australian Stories: History, Testimony and Memory in Contemporary Culture, by Kelly Jean Butle

Heavy Backpack Load Carriage Affects the Median Nerve

First responder and military personal often carry heavy backpacks of over 30% body weight when loaded with equipment. Use of the hands may be impaired by the compression of backpack straps on the nerves of the upper limb. PURPOSE: The aim of the study is to characterize the effects of walking with backpack load on upper limb function by examining changes in nerve conduction resulting from compression of the brachial plexus by backpack straps. We hypothesized that nerve conduction would be decreased in amplitude of the action potential and timing would be delayed after walking while carrying a 30% body weight load in a backpack. METHODS: 27 participants (12 female, 15 male; mean ± SD of 23.0 ± 4.8 yrs, 174.1 ± 10.5 cm height; 78.1 ± 14.9 kg mass, 27 right handed) were measured for motor and sensory nerve conduction using a Natus Neurodiagnostic System to stimulate and record median nerve conduction for the dominant upper limb. The median nerve was stimulated at the wrist for the sensory measures and at the elbow and axilla for motor nerve measurements. Participants walked on a treadmill for 20 minutes at 1.1 m/s while carrying a load of 30% bodyweight in a military-style external frame backpack with hip belt. Measurements were taken before participants donned the backpack (PRE) and immediately after walking while participants were still wearing the backpack (POST). Amplitude and latency of action potentials were recorded. Paired t tests were used to compare PRE and POST values of nerve conduction. RESULTS: Sensory nerve conduction showed significant changes (p=0.040) with a decrease in baseline-to-peak amplitude from 46.6 ± 16.2 µV PRE to 40.8 ± 13.2 µV POST. Latency of the motor nerve action potential was significantly increased (p=0.013) from a mean of 7.46 ± 0.71ms PRE to 7.60 ± 0.86 ms POST when stimulated at the elbow. Stimulation at the axilla also demonstrated significantly increased motor latency (p=0.037) from a mean of 9.36 ± 0.91 ms PRE to 9.49 ± 1.04 ms POST. CONCLUSION: Walking for 20 minutes while carrying a backpack loaded to 30% body weight affected nerve conduction for the median nerve. The increase in latency and decrease in amplitude of nerve conduction after a short bout of walking could potentially affect use of the hand and finger muscles and consequently affect manual task performance

The Effects of Heavy Backpack Carriage on Hand Strength

Force production in upper limb muscles could be affected following exercise that involves carrying a heavy backpack load. In lower limb muscles, previous study has demonstrated that there is muscle force depression after several different regimens of metabolically and mechanically demanding exercise. PURPOSE: The aim of this study is to examine pinch strength after exercising while carrying a heavy backpack with straps that compress the nerves and blood vessels of the upper limb. We hypothesized that backpack load carriage at 15% body weight and 30% body weight will lead to changes in upper limb lateral pinch strength as compared to a no-load condition. METHODS: To date, eleven participants (5 female, 6 male; mean ± SD of 25.8 ± 6.3 yrs, 81.9 ± 18 kg mass, 11 right handed) have completed 3 load conditions on separate days: 1) no backpack, 2) 15% body weight (BW) backpack, and 3) 30% BW backpack. Load condition order was randomized. Maximum lateral pinch strength was measured bilaterally using a pinch dynamometer before and after participants walked on a treadmill at 1.1 m/s for 30 minutes for each load condition. Pinch strength was measured every 5 minutes for 30 minutes after exercise. RMANOVA with Bonferroni post-hoc testing was used to compare among backpack conditions and among timepoints. RESULTS: Mean pinch strength on the dominant hand before backpack carriage was 10.8 ± 2.7 kg for male participants and 8.0 ± 1.2 kg for female participants. Pinch strength on the non-dominant hand before load carriage averaged 9.9 ± 1.7 kg for male participants and 7.5 ± 1.0 kg for female participants. Mean pinch strength on the dominant hand after 30% BW backpack carriage ranged from 10.6-10.9 kg for male participants and from 7.8 - 8.3 kg for female participants. There were no significant differences in pinch strength on either hand when comparing among backpack load conditions or timepoints for male or female participants. CONCLUSION: The compression of backpack straps and the exercise of walking with a backpack load did not affect pinch strength in the first 30 minutes after backpack carriage

Quantifying thresholds of barrier geomorphic change in a cross-shore sediment-partitioning model

Barrier coasts, including barrier islands, beach-ridge plains, and associated landforms, can assume a broad spectrum of morphologies over multi-decadal scales that reflect conditions of sediment availability, accommodation, and relative sea-level rise. However, the quantitative thresholds of these controls on barrier-system behavior remain largely unexplored, even as modern sea-level rise and anthropogenic modification of sediment availability increasingly reshape the world\u27s sandy coastlines. In this study, we conceptualize barrier coasts as sediment-partitioning frameworks, distributing sand delivered from the shoreface to the subaqueous and subaerial components of the coastal system. Using an idealized morphodynamic model, we explore thresholds of behavioral and morphologic change over decadal to centennial timescales, simulating barrier evolution within quasi-stratigraphic morphological cross sections. Our results indicate a wide diversity of barrier behaviors can be explained by the balance of fluxes delivered to the beach vs. the dune or backbarrier, including previously understudied forms of transgression that allow the subaerial system to continue accumulating sediment during landward migration. Most importantly, our results show that barrier state transitions between progradation, cross-shore amalgamation, aggradation, and transgression are controlled largely through balances within a narrow range of relative sea-level rise and sediment flux. This suggests that, in the face of rising sea levels, subtle changes in sediment fluxes could result in significant changes in barrier morphology. We also demonstrate that modeled barriers with reduced vertical sediment accommodation are highly sensitive to the magnitude and direction of shoreface fluxes. Therefore, natural barriers with limited sediment accommodation could allow for exploration of the future effects of sea-level rise and changing flux magnitudes over a period of years as opposed to the decades required for similar responses in sediment-rich barrier systems. Finally, because our model creates stratigraphy generated under different input parameters, we propose that it could be used in combination with stratigraphic data to hindcast the sensitivity of existing barriers and infer changes in prehistoric morphology, which we anticipate will provide a baseline to assess the reliability of forward modeling predictions

Fractionation profiling: a fast and versatile approach for mapping vesicle proteomes and protein-protein interactions.

We developed "fractionation profiling," a method for rapid proteomic analysis of membrane vesicles and protein particles. The approach combines quantitative proteomics with subcellular fractionation to generate signature protein abundance distribution profiles. Functionally associated groups of proteins are revealed through cluster analysis. To validate the method, we first profiled >3500 proteins from HeLa cells and identified known clathrin-coated vesicle proteins with >90% accuracy. We then profiled >2400 proteins from Drosophila S2 cells, and we report the first comprehensive insect clathrin-coated vesicle proteome. Of importance, the cluster analysis extends to all profiled proteins and thus identifies a diverse range of known and novel cytosolic and membrane-associated protein complexes. We show that it also allows the detailed compositional characterization of complexes, including the delineation of subcomplexes and subunit stoichiometry. Our predictions are presented in an interactive database. Fractionation profiling is a universal method for defining the clathrin-coated vesicle proteome and may be adapted for the analysis of other types of vesicles and particles. In addition, it provides a versatile tool for the rapid generation of large-scale protein interaction maps

The effect of coastal landform development on decadal- to millennial-scale longshore sediment fluxes: Evidence from the Holocene evolution of the central mid-Atlantic coast, USA - Sediment Core and Chronology Data

These data are sediment core, radiocarbon, and optically stimulated luminescence (OSL) data from the barrier islands and backbarrier lagoons, bays, and marshes of Assateague Island (VA, USA), Chincoteague Island (VA, USA), and Wallops Island (VA, USA). Vibracore data from Tom’s Cove, a backbarrier bay, were collected using a vibracore system with the ability to core through a ‘moonhole’ on a flat bottom boat. Geoprobe cores were collected using a track-mounted 66DT Geoprobe direct-push drill rig. Select samples from the sediment cores (associated with figures and tables in Shawler et al., 2021) were analyzed using a Beckman-Coulter Laser Diffraction Particle Size Analyzer (LS 13 320 Aqueous Liquid Module) with an applied calculation model that uses Fraunhöfer theory. Data are available as Microsoft Excel Workbooks and can be opened using Excel or numerous free and open sources products such as Google Sheets. Each sediment core data spreadsheet contains a “READ ME” tab with additional detail. The full OSL report from co-author Sebastien Huot is also included and can be accessed with a PDF reader

Interaction between AP-5 and the hereditary spastic paraplegia proteins SPG11 and SPG15.

The AP-5 complex is a recently identified but evolutionarily ancient member of the family of heterotetrameric adaptor proteins (AP complexes). It is associated with two proteins that are mutated in patients with hereditary spastic paraplegia, SPG11 and SPG15. Here we show that the four AP-5 subunits can be coimmunoprecipitated with SPG11 and SPG15, both from cytosol and from detergent-extracted membranes, with a stoichiometry of ∼1:1:1:1:1:1. Knockdowns of SPG11 or SPG15 phenocopy knockdowns of AP-5 subunits: all six knockdowns cause the cation-independent mannose 6-phosphate receptor to become trapped in clusters of early endosomes. In addition, AP-5, SPG11, and SPG15 colocalize on a late endosomal/lysosomal compartment. Both SPG11 and SPG15 have predicted secondary structures containing α-solenoids related to those of clathrin heavy chain and COPI subunits. SPG11 also has an N-terminal, β-propeller-like domain, which interacts in vitro with AP-5. We propose that AP-5, SPG15, and SPG11 form a coat-like complex, with AP-5 involved in protein sorting, SPG15 facilitating the docking of the coat onto membranes by interacting with PI3P via its FYVE domain, and SPG11 (possibly together with SPG15) forming a scaffold

Income inequality and social gradients in children’s height: a comparison of cohort studies from five high-income countries

Background Health and well-being are better, on average, in countries that are more equal, but less is known about how this benefit is distributed across society. Height is a widely used, objective indicator of child health and predictor of lifelong well-being. We compared the level and slope of social gradients in children's height in high-income countries with different levels of income inequality, in order to investigate whether children growing up in all socioeconomic circumstances are healthier in more equal countries. Methods We conducted a coordinated analysis of data from five cohort studies from countries selected to represent different levels of income inequality (the USA, UK, Australia, the Netherlands and Sweden). We used standardised methods to compare social gradients in children's height at age 4-6 years, by parent education status and household income. We used linear regression models and predicted height for children with the same age, sex and socioeconomic circumstances in each cohort. Results The total analytic sample was 37 063 children aged 4-6 years. Gradients by parent education and household income varied between cohorts and outcomes. After adjusting for differences in age and sex, children in more equal countries (Sweden, the Netherlands) were taller at all levels of parent education and household income than children in less equal countries (USA, UK and Australia), with the greatest between-country differences among children with less educated parents and lowest household incomes. Conclusions The study provides preliminary evidence that children across society do better in more equal countries, with greatest benefit among children from the most disadvantaged socioeconomic groups

Merkel cell polyomavirus large T antigen disrupts lysosome clustering by translocating human Vam6p from the cytoplasm to the nucleus

Merkel cell polyomavirus (MCV) has been recently described as the cause for most human Merkel cell carcinomas. MCV is similar to simian virus 40 (SV40) and encodes a nuclear large T (LT) oncoprotein that is usually mutated to eliminate viral replication among tumor-derived MCV. We identified the hVam6p cytoplasmic protein involved in lysosomal processing as a novel interactor with MCV LT but not SV40 LT. hVam6p binds through its clathrin heavy chain homology domain to a unique region of MCV LT adjacent to the retinoblastoma binding site. MCV LT translocates hVam6p to the nucleus, sequestering it from involvement in lysosomal trafficking. A naturally occurring, tumor-derived mutant LT (MCV350) lacking a nuclear localization signal binds hVam6p but fails to inhibit hVam6p-induced lysosomal clustering. MCV has evolved a novel mechanism to target hVam6p that may contribute to viral uncoating or egress through lysosomal processing during virus replication