bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective glycinergic input from vGluT3 amacrine cells confers a suppressed‐by‐contrast trigger feature in a subtype of M1 ipRGCs in the mouse retina
Authors: Lee Seunghoon , Chen Minggang , Shi Yuelin , Zhou Z. Jimmy
Published: July 2021

Key points

M1 intrinsically photosensitive retinal ganglion cells (ipRGCs) are known to encode absolute light intensity (irradiance) for non‐image‐forming visual functions (subconscious vision), such as circadian photoentrainment and the pupillary light reflex.

It remains unclear how M1 cells respond to relative light intensity (contrast) and patterned visual signals.

The present study identified a special form of contrast sensitivity (suppressed‐by‐contrast) in M1 cells, suggesting a role of patterned visual signals in regulating non‐image‐forming vision and a potential role of M1 ipRGCs in encoding image‐forming visual cues.

The study also uncovered a synaptic mechanism and a retinal circuit mediated by vesicular glutamate transporter 3 (vGluT3) amacrine cells that underlie the suppressed‐by‐contrast response of M1 cells.

M1 ipRGC subtypes (M1a and M1b) were revealed that are distinguishable based on synaptic connectivity with vGluT3 amacrine cells, receptive field properties, intrinsic photo sensitivity and membrane excitability, and morphological features, suggesting a division of visual tasks among discrete M1 subpopulations.

The M1 type ipRGC (intrinsically photosensitive retinal ganglion cell) is known to encode ambient light signals for non‐image‐forming visual functions such as circadian photo‐entrainment and the pupillary light reflex. Here, we report that a subpopulation of M1 cells (M1a) in the mouse retina possess the suppressed‐by‐contrast (sbc) trigger feature that is a receptive field property previously found only in ganglion cells mediating image‐forming vision. Using optogenetics and the dual patch clamp technique, we found that vesicular glutamate transporter 3 (vGluT3) (vGluT3) amacrine cells make glycinergic, but not glutamatergic, synapses specifically onto M1a cells. The spatiotemporal and pharmacological properties of visually evoked responses of M1a cells closely matched the receptive field characteristics of vGluT3 cells, suggesting a major role of the vGluT3 amacrine cell input in shaping the sbc trigger feature of M1a cells. We found that the other subpopulation of M1 cells (M1b), which did not receive a direct vGluT3 cell input, lacked the sbc trigger feature, being distinctively different from M1a cells in intrinsic photo responses, membrane excitability, receptive‐field characteristics and morphological features. Together, the results reveal a retinal circuit that uses the sbc trigger feature to regulate irradiance coding and potentially send image‐forming cues to non‐image‐forming visual centres in the brain.
Changes in neural drive to calf muscles during steady submaximal contractions after repeated static stretches
Authors: Mazzo Melissa R. , Weinman Logan E. , Giustino Valerio , Mclagan Bailey , Maldonado John , Enoka Roger M.
Published: July 2021

Key points

Repeated static‐stretching interventions consistently increase the range of motion about a joint and decrease total joint stiffness, but findings on the changes in muscle and connective‐tissue properties are mixed.

The influence of these stretch‐induced changes on muscle function at submaximal forces is unknown. To address this gap in knowledge, the changes in neural drive to the plantar flexor muscles after a static‐stretch intervention were estimated.

Neural drive to the plantar flexor muscles during a low‐force contraction increased after repeated static stretches.

These findings suggest that adjustments in motor unit activity are necessary at low forces to accommodate reductions in the force‐generating and transmission capabilities of the muscle–tendon unit after repeated static stretches of the calf muscles.

Static stretching decreases stiffness about a joint, but its influence on muscle–tendon unit function and muscle activation is unclear. We investigated the influence of three static stretches on changes in neural drive to the plantar flexor muscles, both after a stretch intervention and after a set of maximal voluntary contractions (MVCs). Estimates of neural drive were obtained during submaximal isometric contractions by decomposing high‐density electromyographic signals into the activity of individual motor units from medial gastrocnemius, lateral gastrocnemius and soleus. Motor units were matched across contractions and an estimate of neural drive to the plantar flexors was calculated by normalizing the cumulative spike train to the number of active motor units (normalized neural drive). Mean discharge rate increased after the stretch intervention during the 10% MVC task for all recorded motor units and those matched across conditions (all, P = 0.0046; matched only, P = 0.002), recruitment threshold decreased for motor units matched across contractions (P = 0.022), and discharge rate at recruitment was elevated (P = 0.004). Similarly, the estimate of normalized neural drive was significantly greater after the stretch intervention at 10% MVC torque (P = 0.029), but not at 35% MVC torque. The adjustments in motor unit activity required to complete the 10% MVC task after stretch may have been partially attenuated by a set of plantar flexor MVCs. The increase in neural drive required to produce low plantar‐flexion torques after repeated static stretches of the calf muscles suggests stretch‐induced changes in muscle and connective tissue properties.
Real-Time Experimental Performance Assessment of a Photovoltaic Thermal System Cascaded With Flat Plate and Heat Pipe Evacuated Tube Collector
Authors: Kumar Laveet , Hasanuzzaman M. , Rahim N. A.
Published: July 2021

In response to the global quest for a sustainable and environmentally friendly source of energy, most scientists’ discretion is solar energy, especially solar thermal. However, successful deployment of solar thermal technologies such as solar-assisted process heating (SAPH) systems in medium- to large-scale industries is still in quandary due to their inefficacy in raising ample temperatures. Cascaded SAPH system, which is essentially a series combination of two same or different types of thermal collectors, may provide a worthwhile solution to this problem. In this article, performance assessment and comparison of two cascaded SAPH systems have been presented: photovoltaic thermal (PVT) cascaded with flat-plate collector (PVT-FPC) and PVT coupled with heat pipe evacuated tube collector (PVT-HPETC). Simulation models have been presented for individual FPC, HPETC, and PVT as well as PVT cascaded with FPC and HPETC systems in TRNSYS and validated through outdoor experimentation. Both the first and the second laws of thermodynamics have been employed to reveal veritable performance of the systems. Results show that PVT-HPETC delivers better performance with 1625 W thermal energy, 81.59% energy efficiency, and 13.22% exergy efficiency. It cuts 1.37 kg of CO2 on an hourly basis. Cascaded systems can be effective in sustaining industrial process heat requirements.
Surface Integrity and Flank Wear Response Under Pure Coconut Oil-Al2O3 Nano Minimum Quantity Lubrication Turning of Al-7079/7 wt%-TiC In Situ Metal Matrix Composites
Authors: Sujith S. V. , Mulik Rahul S.
Published: July 2021

Major cooling and lubricating properties such as conduction, convection, and lubricant stability at higher temperatures are improvised by the addition of nanoparticle into metal cutting fluids. The present investigation is mainly focused on the effects of pure coconut oil (PC)-based nanofluids through minimum quantity lubrication (MQL) on oblique cutting performance of Al-7079/7 wt%-TiC in situ reinforced metal matrix composites (MMCs). The machining performance has been evaluated under dry machining, pure coconut oil (PC)-MQL, and MQL by varying 0.1% to 0.6 vol% nanoparticles into PC. The performance of nano cutting fluids was compared to dry machining and PC machining in terms of cutting forces, tool wear, cutting zone temperature, and surface roughness. It was found that, compared to dry and PC-MQL machining, the performance of nano MQL machining was superior among all cutting conditions. However, above 0.4% nano particles, the nano MQL performance was degraded drastically, which leads to the substantial increment in cutting forces, tool wear, surface roughness, and cutting zone temperature.
Delayed-Detached Eddy Simulations of Film Cooling Effect on Trailing Edge Cutback With Land Extensions
Authors: Wang Ruiqin , Yan Xin
Published: July 2021

Film cooling effect on trailing edge cutback with land extensions (i.e., landed case) was numerically investigated with the delayed-detached eddy simulation (DDES) method. At three rib geometries (i.e., inline rib arrays, six-row pin-fin arrays, and five-row pin-fin arrays) and five blowing ratios (i.e., M = 0.5, 0.8, 1.1, 1.5, and 2.0), film cooing effectiveness, coherent vortex structures, and discharge coefficients for the landed cases were analyzed and compared with baseline cases (i.e., cutback without land extensions). The results show that land extensions have significant influences on coherent flow structures, vortex energy levels, film cooling effectiveness, and discharge coefficients in cutback region. Different from the baseline cases, the dominant vortex structures in landed cases exhibit the “double helix” (for cutback with inline rib array) or “strip” pattern (for cutback with pin-fin arrays), and the thickness of mixing region in landed cases is decreased. Among three rib geometries, the trailing edge cutback with six-row pin-fin arrays has the worst cooling effect for both baseline and landed cases. Compared with the baseline cases, the discharge coefficients for the landed cases are decreased by about 21.4%. With land extensions, the overall film cooling effectiveness on cutback is decreased first and then increased with increasing blowing ratio. Among all investigated cases, cutback with five-row pin-fin arrays for the landed case performs the best film cooling effect at M = 0.5.
Impact of Mistuned Underplatform Dampers on the Nonlinear Vibration of Bladed Disks
Authors: Quaegebeur Samuel , Chouvion Benjamin , Thouverez Fabrice
Published: July 2021

Before the final experimental validation and certification of a turbo-engine, designers perform a numerical simulation of its vibratory properties, among other things, in order to estimate its lifespan and adjust the design in an optimization process. One possible practical solution to decrease the vibratory response is to add underplatform dampers to the system. These components dissipate energy by friction and are widely employed in turbomachinery. However, a specific underplatform damper is usually efficient only for a specific mode. The purpose of this work is to investigate the possibility of adding different kinds of underplatform dampers to the cyclic structure in order to decrease the vibratory energy over a larger panel of modes. Different methods exist to determine the vibrations of nonlinear cyclic symmetric systems, but creating a robust methodology to account for the additional effect of mistuning remains a big challenge in the community. In this paper, the structure is mistuned through the friction coefficient of the dampers and not by altering its geometry, as is usually done in the literature. First, assuming a cyclic symmetric structure, the performance of the dampers is assessed for specific modes. Then, employing a method recently developed, the efficiency of an intentional mistuning pattern of underplatform dampers is studied and an optimal pattern proposed.
Fiber- and Particle-Reinforced Composite Materials With the Gurtin–Murdoch and Steigmann–Ogden Surface Energy Endowed Interfaces
Authors: Mogilevskaya Sofia G. , Zemlyanova Anna Y. , Kushch Volodymyr I.
Published: July 2021

Modern advances in material science and surface chemistry lead to creation of composite materials with enhanced mechanical, thermal, and other properties. It is now widely accepted that the enhancements are achieved due to drastic reduction in sizes of some phases of composite structures. This leads to increase in surface to volume ratios, which makes surface- or interface-related effects to be more significant. For better understanding of these phenomena, the investigators turned their attention to various theories of material surfaces. This paper is a review of two most prominent theories of that kind, the Gurtin–Murdoch and Steigmann–Ogden theories. Here, we provide comprehensive review of relevant literature, summarize the current state of knowledge, and present several new results.
Demonstrating SolarPILOT’s Python API Through Heliostat Optimal Aimpoint Strategy Use Case
Authors: Hamilton William T. , Wagner Michael J. , Zolan Alexander J.
Published: July 2021

SolarPILOT is a software package that generates solar field layouts and characterizes the optical performance of concentrating solar power (CSP) tower systems. SolarPILOT was developed by the National Renewable Energy Laboratory (NREL) as a stand-alone desktop application but has also been incorporated into NREL’s1 System Advisor Model (SAM) in a simplified format. Prior means for user interaction with SolarPILOT have included the application’s graphical interface, the SAM routines with limited configurability, and through a built-in scripting language called “LK.” This paper presents a new, full-featured, Python-based application programmable interface (API) for SolarPILOT, which we hereafter refer to as CoPylot.

CoPylot provides access to all SolarPILOT’s capabilities to generate and characterize power tower CSP systems seamlessly through Python. Supported capabilities include (i) creating and destroying a model instance with message reporting tools; (ii) accessing and setting any SolarPILOT variable including custom land boundaries for field layouts; (iii) programmatically managing receiver and heliostat objects with varied attributes for systems with multiple receiver or heliostat types; (iv) generating, assigning, and modifying solar field layouts including the ability to set individual heliostat locations, aimpoints, soiling rates, and reflectivity levels; (v) simulating solar field performance; (vi) returning detailed results describing performance of individual heliostats, the aggregate field, and receiver flux distribution; and, (vii) exporting Python-based model instances to multiple file formats.

CoPylot enables Python users to perform detailed CSP tower analysis utilizing either the Hermite expansion technique (analytical) or the SolTrace ray-tracing engine. In addition to CoPylot’s functionality, Python users have access to the over 100,000 open-source libraries to develop, analyze, optimize, and visualize power tower CSP research. This enables CSP researchers to perform analysis that was previously not possible through SolarPILOT’s existing interfaces. This paper discusses the capabilities of CoPylot and presents a use case wherein we demonstrate optimal solar field aiming strategies.
Design and Feasibility Study of Biomass-Driven Combined Heat and Power Systems for Rural Communities
Authors: Schicker Philippe C. , Spayde Dustin , Cho Heejin
Published: July 2021

Meeting energy demands at crucial times can often be jeopardized by unreliable power supply from the grid. Local, on-site power generation, such as combined heat and power (CHP) systems, may safeguard against grid fluctuations and outages. CHP systems can provide more reliable and resilient energy supply to buildings and communities while it can also provide energy-efficient, cost-effective, and environmentally sustainable solutions compared to centralized power systems. With a recent increased focus on biomass as an alternative fuel source, biomass driven CHP systems have been recognized as a potential technology to bring increased efficiency of fuel utilization and environmentally sustainable solutions. Biomass as an energy source is already created through agricultural and forestry byproducts and may thus be efficient and convenient to be transported to remote rural communities. This paper presents a design and feasibility analysis of biomass (primarily wood pellets)-driven CHP systems for a rural community in the United States. A particular focus was set on rural Mississippi to investigate possible grid independent applications; however, this analysis can be scaled to rural communities across America. The viability of wood pellets (WP) as a suitable fuel source is explored by comparing it to a conventional grid-connected system. To measure viability, three performance parameters — operational cost (OC), primary energy consumption (PEC), and carbon dioxide emission (CDE) — are considered in the analysis. The results demonstrate that under the right conditions wood pellet-fueled CHP systems create economic and environmental advantages over traditional systems. The main factors in increasing the viability of bCHP systems are the appropriate sizing and operational strategies of system and the purchase price of biomass with respect to the price traditional fuels.
Proposed Design and Integration of 1.3 MWe Pre-Commercial Demonstration Particle Heating Receiver Based Concentrating Solar Power Plant
Authors: Sarfraz Muhammad , Yeung Ryan , Repole Kenzo , Golob Matthew , Jeter Sheldon , Al-Ansary Hany , El-Leathy Abdelrahman , Alaqel Shaker , Saleh Nader S. , Saeed Rageh , Alswaiyd Abdulelah
Published: July 2021

Particle heating receiver (PHR) based concentrating solar power (CSP) is widely recognized as the preferred path to reliable and cost-effective solar power. Use of solid particles rather than conventional fluids such as molten salts as collection and storage media, enables the operation of the PHR-based CSP plant at elevated temperatures (∼1000°C). This advantage leads to higher efficiency and lower levelized cost of energy (LCOE) produced by PHR-based CSP plants. However, designing and integrating the commercial solar power plant at high operating temperatures (∼1000°C), is a substantial challenge which has been overcome. Our research teams at King Saud University (KSU) and the Georgia Institute of Technology (GIT) have been working on the design and development of high temperature key sub-systems in PHR-based CSP plants. The proposed 1.3 MWe pre-commercial demonstration (PPCD) plant will incorporate the design evolved from our risk-reducing research activities performed at 300kW test facility at KSU and GIT. The DS-PHR of the PPCD will incorporate the KSU’s patented discrete-structured design in which the receiver will be enclosed in a cavity to minimize radiative and convective heat losses. Each PHR panel will have efficient particle flow control system for uniform particles outlet temperatures. Low-cost particulate materials with enhanced solar absorptance and resilience at high-temperatures have been identified to be used as heat collection and storage media. Inexpensive thermal energy storage (TES) bins will accommodate sand with temperatures ∼ 1000 °C. Multiple layered design of the TES bins will limit the heat loss to less than 1% per day (at scale). The current TES design allows easy access to the high-temperature bins for experimental observation and for future modifications. A patent pending skip hoist particle lift system design will be used for particle conveyance with expected mechanical efficiency of 75–85 %. Our lift design is simple, demonstrates autonomous operation with minimal mechanical complexity, minimized heat loss, and reduced maintenance. The heat exchanger proposed is a multi-pass shell-tubes design with high heat transfer coefficient. The design features discussed in this paper will lead to large scale commercial plants and similar small-scale designs for off-grid and remote applications at our anticipated service location which is in Saudi Arabia, and in Mideast and North Africa (MENA) region.
Resiliency Evaluation of Net-Zero Residential Communities
Authors: Thompson Jordan , Krarti Moncef
Published: July 2021

In this report, a resiliency analysis is carried out to assess the energy, economic, and power outage survivability benefits of efficient and Net-Zero communities. The analysis addresses the appropriate steps to designing an energy-efficient and Net-Zero community using Phoenix, Arizona as a primary location for weather and utility inputs. A baseline home is established using International Energy Conservation Code (IECC) 2018 code requirements. Three occupancy levels are evaluated in BEopt to provide diversity in the community’s building stock. The loads from the baseline, energy-efficient optimum, and Net-Zero optimum single-family homes are utilized to determine energy use profiles for various residential community types using occupancy statistics for Phoenix. Then, REopt is used to determine the photovoltaic (PV) and battery storage system sizes necessary for the community to survive a 72-hour power outage. The baseline community requires a 544-kW PV system and 375-kW/1,564 kWh battery storage system to keep all electrical loads online during a 72-hour power outage. The energy-efficient community requires a 291-kW PV system and a 202-kW/820 kWh battery storage system while the Net-Zero community requires a 291-kW PV system and a 191-kW/880 kWh battery storage system. In this study, the economic analysis indicates that it is 43% more cost-effective to install a shared PV plus storage system than to install individual PV plus storage systems in an energy-efficient community. After analyzing the system sizes and costs required to survive various outage durations, it is found that only a 4% difference in net present cost exists between a system sized for a 24-hour outage and a 144-hour outage. In the event of a pandemic or an event that causes a community-wide lockdown, the energy-efficient community would only survive 6 hours out of a 72-hour power outage during a time where plug loads are increased by 50% due to added laptops, monitors, and other office electronics. Finally, a climate sensitivity analysis is conducted for efficient communities in Naperville, Illinois and Augusta, Maine. The analysis suggests that for a 72-hour power outage starting on the peak demand day and time of the year, the cost of resiliency is higher in climates with more heating and cooling needs as HVAC is consistently the largest load in a residential building.
Evaluation of Simplified Physics-Based Building Energy Model for the Purpose of Automatic Fault Detection
Authors: Fernandez Christopher , Jeter Sheldon
Published: July 2021

Buildings are complex systems with dynamic loading and ever-changing usage. Additionally, there is a need to reduce unnecessary energy consumption while increasing occupant health in buildings via implementation of manual fault detection with available building design programs. However, a common problem with the current lineup of programs is that they require extensive inputs for material properties and usage loads; this results in spending extensive amounts of time performing model calibration and having to adjust multiple values (sometimes hundreds) to bring a model in alignment with actual building use. However, a simplified physics-based model (SPBM) can achieve a level of modeling accuracy sufficient for automatic fault detection with as few as ten automatically calibrated unknown parameters. Obviously, other simplified building energy models exist; however, these often rely on ignoring important details, such as humidity, CO2, and per-hour performance, or implement averaged numerical estimations. Due to the limitations of current modeling programs, some development has begun on rule-based and component-based fault detection by several companies and researchers. While component-based fault detection is effective, it relies on accurate sensor readings and does not account for actual building performance. A suitable rigorous physics-based model has not been developed for the purpose of fault detection. Therefore, by comparing the accuracy of an automatically calibrated SPBM with real-world building performance and high-fidelity building energy models will provide baseline knowledge about if such a model can even achieve a high enough level of fidelity to reliably represent the complexity of a building.
Experimental Investigation of Lab-Scale, Heat Exchanger Prototypes Designed to Provide Refugia for Trout
Authors: Rony Rajib Uddin , Gladen Adam , LaVallie Sarah , Kientz Jeremy
Published: July 2021

In recent years Spring Creek in South Dakota, a popular fishing location, has been experiencing higher surface water temperatures, which negatively impact cold-water trout species. One potential solution is to provide localized refugia of colder water produced via active cooling. The present work focuses on the design and testing of a small-scale prototype heat exchanger, for such a cooling system. Various prototypes of the heat exchanger were tested in a 1/10th-scaled model of a section of the creek. A staggered, tube-bundle heat exchanger was used. The prototypes consisted of just the heat exchanger placed directly in the scaled-stream model and of the heat exchanger placed inside an enclosure with an aperture. The results show that, without the enclosure, the average temperature difference is 0.64 °C, with a corresponding heat transfer requirement of 1.63 kW/°C of cooling. However, with an enclosure, the average temperature difference is 1.95 °C, which required 0.59 kW/°C of cooling. Modifications to the enclosure decrease the average temperature difference but also decrease the standard deviation of the temperature difference. Thus, the cooling effect is more evenly spread throughout the water in the enclosure. This indicates that the enclosure design can be used to balance the requirements of obtaining a desired temperature difference with a relatively low spatial variation in that temperature difference. These results will be used to guide the design of the large-scale heat exchanger prototype.
Perspectives from research on metal-semiconductor contacts: Examples from Ga2O3, SiC, (nano)diamond, and SnS
Authors: Porter Lisa M. , Hajzus Jenifer R.
Published: July 2021

As part of a Special Issue in Honor of 30 years of the American Vacuum Society’s Nellie Yeoh Whetten Award, this Invited Perspective discusses results and trends from the authors’ and other published research on metal contacts to β-Ga2O3, (4H and 6H)-SiC, nanocrystalline diamond (NCD), and nanocrystalline thin films and single-crystalline nanoribbons of α-SnS. The paper is not a comprehensive review of research on contacts to each of these semiconductors; it is instead a perspective that focuses on Schottky barrier height (Φb) measurements and factors that affect Φb, such as metal work function (Φm) and crystallographic surface plane. Metals and the associated processing conditions that form ohmic or Schottky contacts to each of these semiconductors are also described. Estimates of the index of interface behavior, S, which measures the dependence of Φb on Φm, show large variations both among different semiconductors (e.g., S ∼ 0.3 for NCD and S ∼ 1.0 for SnS nanoribbons) and between different surface planes of the same semiconductor [e.g., (2¯01) vs (100) Ga2O3]. The results indicate that Φb is strongly affected by the nature of the semiconductor surface and near-surface region and suggest that the sharp distinction between covalent and ionic semiconductors as described in seminal theories can be adjustable.
Automatic responses to musical intervals: Contrasts in acoustic roughness predict affective priming in Western listeners
Authors: Armitage James , Lahdelma Imre , Eerola Tuomas
Published: July 2021

The aim of the present study is to determine which acoustic components of harmonic consonance and dissonance influence automatic responses in a simple cognitive task. In a series of affective priming experiments, eight pairs of musical intervals were used to measure the influence of acoustic roughness and harmonicity on response times in a word-classification task conducted online. Interval pairs that contrasted in roughness induced a greater degree of affective priming than pairs that did not contrast in terms of their roughness. Contrasts in harmonicity did not induce affective priming. A follow-up experiment used detuned intervals to create higher levels of roughness contrasts. However, the detuning did not lead to any further increase in the size of the priming effect. More detailed analysis suggests that the presence of priming in intervals is binary: in the negative primes that create congruency effects the intervals' fundamentals and overtones coincide within the same equivalent rectangular bandwidth (i.e., the minor and major seconds). Intervals that fall outside this equivalent rectangular bandwidth do not elicit priming effects, regardless of their dissonance or negative affect. The results are discussed in the context of recent developments in consonance/dissonance research and vocal similarity.
Retinal waves prime visual motion detection by simulating future optic flow
Authors: Ge Xinxin , Zhang Kathy , Gribizis Alexandra , Hamodi Ali S. , Sabino Aude Martinez , Crair Michael C.
Published: July 2021

Developing neurons practice for real life

As a mouse runs forward across the forest floor, the scenery that it passes flows backwards. Ge
et al
. show that the developing mouse retina practices in advance for what the eyes must later process as the mouse moves. Spontaneous waves of retinal activity flow in the same pattern as would be produced days later by actual movement through the environment. This patterned, spontaneous activity refines the responsiveness of cells in the brain’s superior colliculus, which receives neural signals from the retina to process directional information. —PJH
Enterically derived high-density lipoprotein restrains liver injury through the portal vein
Authors: Han Yong-Hyun , Onufer Emily J. , Huang Li-Hao , Sprung Robert W. , Davidson W. Sean , Czepielewski Rafael S. , Wohltmann Mary , Sorci-Thomas Mary G. , Warner Brad W. , Randolph Gwendalyn J.
Published: July 2021

Intestinal HDL is hepatoprotective

High-density lipoprotein (HDL) is important for cholesterol metabolism and may have anti-inflammatory and antimicrobial properties. Although HDL is mainly produced by the liver, the intestine is also a source. Han
et al.
show in mice that intestinal HDL is not routed to the systemic circulation. Rather, in the form of HDL3, it is directly transported to the liver through the hepatic portal vein. There, it sequesters bacterial lipopolysaccharide from the gut that can trigger inflammation and liver damage. In various models of liver injury, loss of enteric HDL exacerbated pathology. By contrast, drugs elevating intestinal HDL improved disease outcomes. HDL3 is enriched in human portal venous blood, suggesting that enteric HDL may be targetable for the treatment of liver disease.

Science
, abe6729, this issue p.
eabe6729
Experimental jurisprudence
Authors: Sommers Roseanna
Published: July 2021

Psychologists probe lay understandings of legal constructs
Thickness and structure of the martian crust from InSight seismic data
Authors: Knapmeyer-Endrun Brigitte , Panning Mark P. , Bissig Felix , Joshi Rakshit , Khan Amir , Kim Doyeon , Lekić Vedran , Tauzin Benoit , Tharimena Saikiran , Plasman Matthieu , Compaire Nicolas , Garcia Raphael F. , Margerin Ludovic , Schimmel Martin , Stutzmann Éléonore , Schmerr Nicholas , Bozdağ Ebru , Plesa Ana-Catalina , Wieczorek Mark A. , Broquet Adrien , Antonangeli Daniele , McLennan Scott M. , Samuel Henri , Michaut Chloé , Pan Lu , Smrekar Suzanne E. , Johnson Catherine L. , Brinkman Nienke , Mittelholz Anna , Rivoldini Attilio , Davis Paul M. , Lognonné Philippe , Pinot Baptiste , Scholz John-Robert , Stähler Simon , Knapmeyer Martin , van Driel Martin , Giardini Domenico , Banerdt W. Bruce
Published: July 2021

Single seismometer structure

Because of the lack of direct seismic observations, the interior structure of Mars has been a mystery. Khan
et al.
, Knapmeyer-Endrun
et al.
, and Stähler
et al.
used recently detected marsquakes from the seismometer deployed during the InSight mission to map the interior of Mars (see the Perspective by Cottaar and Koelemeijer). Mars likely has a 24- to 72-kilometer-thick crust with a very deep lithosphere close to 500 kilometers. Similar to the Earth, a low-velocity layer probably exists beneath the lithosphere. The crust of Mars is likely highly enriched in radioactive elements that help to heat this layer at the expense of the interior. The core of Mars is liquid and large, ∼1830 kilometers, which means that the mantle has only one rocky layer rather than two like the Earth has. These results provide a preliminary structure of Mars that helps to constrain the different theories explaining the chemistry and internal dynamics of the planet.

Science
, abf2966, abf8966, abi7730, this issue p.
434
, p.
438
, p.
443
see also abj8914, p.
388
Scent of a vaccine
Authors: Lund Frances E. , Randall Troy D.
Published: July 2021

Intranasal vaccination should block SARS-CoV-2 transmission at the source
Global implications of the EU battery regulation
Authors: Melin Hans Eric , Rajaeifar Mohammad Ali , Ku Anthony Y. , Kendall Alissa , Harper Gavin , Heidrich Oliver
Published: July 2021

A much-needed law may have unintended global consequences
Colleges need vaccine mandates
Authors: Thorp H. Holden
Published: July 2021

Finally, in the United States, colleges and universities are ramping up for a relatively normal school year. Most pandemic restrictions have been lifted and—barring any unforeseen new coronavirus variants—parents and students will soon be pulling up to residence halls and unloading their belongings. At many schools in “blue” states, there will be a great deal of confidence that good times are on the horizon as everyone there will have shown proof of vaccination against COVID-19. But for some public universities in “red” states, where vaccine mandates are not permitted, an aura of uncertainty will hang over the campus and the local community, a foreboding sense that another outbreak could be at hand.
Supplemental Material: Progressive accretion recorded in sedimentary rocks of the 3.28–3.23 Ga Fig Tree Group, Barberton Greenstone Belt
Authors: Drabon Nadja , Lowe Donald R.
Published: July 2021

Supplemental File S1: Additional figures; Supplemental File S2: List of dated tuffs of the Fig Tree Group; Supplemental File S3: U-Pb geochronological data; Supplemental File S4: Mudstone geochemical data.
Mycotic aneurysm of the distal radial artery after cardiac catheterisation
Authors: Nguyen Audrey B , Rosser Micaela , Hansen Scott L
Published: July 2021

A mycotic aneurysm of the distal radial artery following access for cardiac catheterisation is a rare complication that has not been described in the literature. We present the case of an 84-year-old man who developed bacteraemia and cellulitis over his left first dorsal webspace 2 days after undergoing cardiac catheterisation through the distal radial artery at the anatomic snuffbox. Ultrasound scanning and CT imaging were concerning for a possible pseudoaneurysm at that location. Once we confirmed that the patient had adequate flow through his hand with angiography and an Allen’s test, we explored his left hand and found a mycotic aneurysm of the distal radial artery with surrounding frank purulence. We resected the aneurysm and ligated the artery. Pathology confirmed that this was a mycotic aneurysm. The patient quickly recovered from his infection after this definitive treatment.
Neuropathic pain post-COVID-19: a case report
Authors: McWilliam Matthew , Samuel Michael , Alkufri Fadi Hasan
Published: July 2021

A 61-year-old man with no significant medical history developed fever, headache and mild shortness of breath. He tested positive for SARS-CoV-2 and self-isolated at home, not requiring hospital admission. One week after testing positive, he developed acute severe burning pain affecting his whole body, subsequently localised distally in the limbs. There was no ataxia or autonomic failure. Neurological examination was unremarkable. Electrophysiological tests were unremarkable. Skin biopsy, lumbar puncture, enhanced MRI of the brachial plexus and MRI of the neuroaxis were normal. His pain was inadequately controlled with pregabalin but improved while on a weaning regimen of steroids. This case highlights the variety of possible symptoms associated with SARS-CoV-2 infection.
Generalised myoclonus associated with COVID-19 infection
Authors: Ram Aatma , Jeelani Hafiz , Kumar Dilpat , Patel Heeren
Published: July 2021

Postinfectious generalised myoclonus has been reported after many viral and bacterial infections in the past. Recently, some case reports have described it in the context of COVID-19 infection. Most patients described in these case reports are either critically ill and intubated or have concurrent respiratory symptoms. Herein, we present a case of a 79-year-old man, who was recovering from a recent COVID-19 infection, presented with isolated generalised myoclonus. The patient was treated with levetiracetam, a short course (10 days) of dexamethasone, and required extensive rehabilitation. Outpatient follow-up at 2 months suggested complete resolution of symptoms and levetiracetam was subsequently discontinued. This case highlights that generalised myoclonus can occur as a delayed complication of COVID-19 infection.
Methicillin-resistantStaphylococcus aureus(MRSA)-associated juvenile osteomyelitis of mandible: a rare variant
Authors: Chacko Rabin , Kumar Saurabh , Verghese Valsan Philip , Charllu Arun Paul
Published: July 2021

Mandibular osteomyelitis in paediatric population presents as painful swelling with progressive trismus. Often the aetiology for this form of progressive osteomyelitis is inconclusive. The infective aetiology in this condition is difficult to assign as bone tissue culture is found to be seldom positive. We present a case of an 11-year-old girl, with hearing and speech impairment, who presented with report of painful right-sided mandibular swelling with progressive trismus. Clinical, radiographic and histopathological findings were suggestive of sclerotic osteomyelitis. Bone tissue culture grew Methicillin-resistantStaphylococcus aureus, indicating a rare infective variant. Unlike the common belief, where osteomyelitic mandible needs a combination of medical and surgical management, our case was managed conservatively with only antibiotic therapy. Our patient responded well to the treatment with reduction in pain and gradual improvement in the mouth opening. Radiographically the mandibular involvement also showed complete regression.
Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study
Authors: Lee Seung Won , Lee Jinhee , Moon Sung Yong , Jin Hyun Young , Yang Jee Myung , Ogino Shuji , Song Mingyang , Hong Sung Hwi , Abou Ghayda Ramy , Kronbichler Andreas , Koyanagi Ai , Jacob Louis , Dragioti Elena , Smith Lee , Giovannucci Edward , Lee I-Min , Lee Dong Hoon , Lee Keum Hwa , Shin Youn Ho , Kim So Young , Kim Min Seo , Won Hong-Hee , Ekelund Ulf , Shin Jae Il , Yon Dong Keon
Published: July 2021

Purpose

To determine the potential associations between physical activity and risk of SARS-CoV-2 infection, severe illness from COVID-19 and COVID-19 related death using a nationwide cohort from South Korea.

Methods

Data regarding 212 768 Korean adults (age ≥20 years), who tested for SARS-CoV-2, from 1 January 2020 to 30 May 2020, were obtained from the National Health Insurance Service of South Korea and further linked with the national general health examination from 1 January 2018 to 31 December 2019 to assess physical activity levels. SARS-CoV-2 positivity, severe COVID-19 illness and COVID-19 related death were the main outcomes. The observation period was between 1 January 2020 and 31 July 2020.

Results

Out of 76 395 participants who completed the general health examination and were tested for SARS-CoV-2, 2295 (3.0%) were positive for SARS-CoV-2, 446 (0.58%) had severe illness from COVID-19 and 45 (0.059%) died from COVID-19. Adults who engaged in both aerobic and muscle strengthening activities according to the 2018 physical activity guidelines had a lower risk of SARS-CoV-2 infection (2.6% vs 3.1%; adjusted relative risk (aRR), 0.85; 95% CI 0.72 to 0.96), severe COVID-19 illness (0.35% vs 0.66%; aRR 0.42; 95% CI 0.19 to 0.91) and COVID-19 related death (0.02% vs 0.08%; aRR 0.24; 95% CI 0.05 to 0.99) than those who engaged in insufficient aerobic and muscle strengthening activities. Furthermore, the recommended range of metabolic equivalent task (MET; 500–1000 MET min/week) was associated with the maximum beneficial effect size for reduced risk of SARS-CoV-2 infection (aRR 0.78; 95% CI 0.66 to 0.92), severe COVID-19 illness (aRR 0.62; 95% CI 0.43 to 0.90) and COVID-19 related death (aRR 0.17; 95% CI 0.07 to 0.98). Similar patterns of association were observed in different sensitivity analyses.

Conclusion

Adults who engaged in the recommended levels of physical activity were associated with a decreased likelihood of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related death. Our findings suggest that engaging in physical activity has substantial public health value and demonstrates potential benefits to combat COVID-19.
Physical sleeping environment is related to insomnia risk and measures of readiness in US army special operations soldiers
Authors: Mantua Janna , Ritland B M , Naylor J A , Simonelli G , Mickelson C A , Choynowski J J , Bessey A F , Sowden W J , Burke T M , McKeon A B
Published: July 2021

Background

US military service members have characteristically poor sleep, even when ‘in garrison’ or at one’s home base. The physical sleeping environment, which is often poor in military-provided housing or barracks, may contribute to poor sleep quality in soldiers. The current study aimed to assess whether the sleeping environment in garrison is related to sleep quality, insomnia risk and military readiness.

Methods

Seventy-four US army special operations soldiers participated in a cross-sectional study. Soldiers were queried on their sleeping surface comfort and the frequency of being awakened at night by excess light, abnormal temperatures and noise. Subjective sleep quality and insomnia symptoms were also queried, via the Pittsburgh Sleep Quality Index and Insomnia Severity Index, respectively. Lastly, measures of soldier readiness, including morale, motivation, fatigue, mood and bodily pain, were assessed.

Results

Soldiers reporting temperature-related and light-related awakenings had poorer sleep quality higher fatigue and higher bodily pain than soldiers without those disturbances. Lower ratings of sleeping surface comfort were associated with poorer sleep quality and lower motivation, lower morale, higher fatigue and higher bodily pain. Each 1-point increase in sleeping surface comfort decreased the risk for a positive insomnia screen by 38.3%, and the presence of temperature-related awakenings increased risk for a positive insomnia screen by 78.4%. Those living on base had a poorer sleeping environment than those living off base.

Conclusion

Optimising the sleep environment—particularly in on-base, military-provided housing—may improve soldier sleep quality, and readiness metrics. Providers treating insomnia in soldiers should rule out environment-related sleep disturbances prior to beginning more resource-intensive treatment.
Protocol for the development of Core Outcome Sets for Early intervention trials to Prevent Obesity in CHildren (COS-EPOCH)
Authors: Brown Vicki , Moodie Marj , Tran Huong Ngoc Quynh , Sultana Marufa , Hunter Kylie Elizabeth , Byrne Rebecca , Zarnowiecki Dorota , Seidler Anna Lene , Golley Rebecca , Taylor Rachael , Hesketh Kylie D , Matvienko-Sikar Karen
Published: July 2021

Introduction

Childhood overweight and obesity is prevalent in the first 5 years of life, and can result in significant health and economic consequences over the lifetime. The outcomes currently measured and reported in randomised controlled trials of early childhood obesity prevention interventions to reduce this burden of obesity are heterogeneous, and measured in a variety of ways. This variability limits the comparability of findings between studies, and contributes to research waste. This protocol presents the methodology for the development of two core outcome sets (COS) for obesity prevention interventions in children aged from 1 to 5 years from a singular development process: (1) a COS for interventions targeting physical activity and sedentary behaviour and (2) a COS for interventions targeting child feeding and dietary intake. Core outcomes related to physical activity and sedentary behaviour in children aged ≤1 year will also be identified to complement an existing COS for early feeding interventions, and provide a broader set of core outcomes in this age range. This will result in a suite of COS useful for measuring and reporting outcomes in early childhood obesity prevention studies, including multicomponent interventions.

Methods and analysis

Development of the COS will follow international best practice guidelines. A scoping review of trial registries will identify commonly reported outcomes and associated measurement instruments. Key stakeholders involved in obesity prevention, including policy-makers/funders, parents, researchers, health practitioners and community and organisational stakeholders will participate in an e-Delphi study and consensus meeting regarding inclusion of outcomes in the COS. Finally, recommended outcome measure instruments will be identified through literature review and group consensus.

Ethics and dissemination

Deakin University Human Research Ethics Committee (HEAG-H 231_2020). The COS will be disseminated through peer-reviewed publications and engagement with key stakeholders.
Impact of removing prescription charges on health outcomes: protocol for a randomised controlled trial
Authors: Cousins Kimberly , Norris Pauline , Horsburgh Simon , Smith Alesha , Keown Shirley , Samaranayaka Ariyapala , Marra Carlo , Churchward Marianna
Published: July 2021

Introduction

Prescription charges prevent many people from accessing the medicines they need to maintain or improve their health. In New Zealand, where most people pay $5 per prescription item, Māori and Pacific peoples, those living in most deprived areas and those with chronic health conditions are the most likely to report that cost prevents them from accessing medicines.

Methods and analysis

This randomised controlled trial (RCT) will evaluate the effect of removing prescription charges on health outcomes and healthcare utilisation patterns of people with low income and high health needs. We will enrol 2000 participants: half will be allocated to the intervention group and we will pay for their prescription charges for 12 months. The other half will receive usual care. The primary outcome will be hospital bed-days. Secondary outcomes will be: all-cause and diabetes/mental health-specific hospitalisations, prescription medicines dispensed (number and type), deaths, emergency department visits and quality of life as measured by the 5-level EQ-5D version. Costs associated with these outcomes will be compared in an economic substudy. A qualitative substudy will also help understand the impact of free prescriptions on participant well-being using in-depth interviews.

Discussion

Being unable to afford prescription medicines is only one of many factors that influence adherence to medicines, but removing prescription charges is relatively simple and in New Zealand would be cheap compared with other policy changes. This RCT will help identify the extent of the impact of a simple intervention to improve access to medicines on health outcomes and health service utilisation.

Ethics and dissemination

This study was approved by the Central Health and Disability Ethics Committee (NZ) in July 2019 (19/CEN/33). Findings will be reported in peer-reviewed publications, as well as in professional newsletters, mainstream media and through public meetings.

Trial registration number

ACTRN12618001486213p.