bluuebunny/crossref_metadata_2025 huggingface dataset:
MRI utricle diameter asymmetry is significantly greater in dogs with idiopathic vestibular syndrome compared with unaffected dogs
Authors: Won Sungjun , Yoon Junghee
Published: July 2020

Idiopathic vestibular syndrome (IVS) is the most common cause of acute unilateral peripheral vestibular dysfunction in older dogs. The purpose of this retrospective, cross‐sectional study was to characterize morphological changes in the utricle of dogs affected by IVS, using MRI. To evaluate differences between affected and unaffected utricles, the ratio of the largest to the smallest utricle diameter was obtained, as measured on transverse T2‐weighted images, and defined as the utricle asymmetricity ratio (UAR). Out of 137 patients diagnosed with IVS after excluding other vestibular diseases by MRI, 101 were eligible for inclusion. Additionally, 31 older dogs with no signs of vestibular disorders or other intracranial diseases were included as a control group. The disease group was divided into two subgroups in which the direction of head tilt and nystagmus symptoms versus the decreased utricle diameters were consistent or inconsistent. The medians of UARs of the IVS and control groups were 0.83 (range 0.37‐1.00) and 0.98 (0.70‐1.00), respectively. The medians of the UARs of the consistent and inconsistent IVS subgroups were 0.82 (0.37‐0.99) and 0.90 (0.74‐1.00), respectively. The UAR of the IVS group was significantly decreased than that of the control group and UAR of the consistent sub‐group was significantly decreased than that of the inconsistent sub‐group (P < .01). In conclusion, significant asymmetry of utricle diameter was identified in dogs with IVS versus unaffected dogs. We propose that canine IVS may possibly be correlated with structural atrophy of the vestibular system.
Educating Engineering Students in Egypt: A Stakeholders’ Perspective, Using Narrative Qualitative Approach
Authors: Elsafty Ashraf Saeed , ElSayad Hanaa , Shaaban Ibrahim
Published: July 2020

This is part of a series of three papers in a research project examining engineering education in Egypt. After concerns from several stakeholders about the graduates’ knowledge and skills, a fresh look at the phenomenon is attempted. In this manuscript the views of stakeholders, using narrative approach and analysis was carried out. The methodology followed a narrative approach, conducting stakeholder’s analysis with relevant and related people to engineering education (Coulter and Smith 2009; Sfard and Prusak, 2005). The sample included students & fresh graduates, engineers with several years of experience, others with long experiences, academics, parents and administrative staff, were elicited. The responses were collected by asking two questions via social media. The aim was to obtain a quick idea on how stakeholders perceive engineering education in Egypt, and the enhancements they would like to see. Importance of the study comes from both linking with three papers in series exploring engineering education in Egypt, and the in-depth narrative reflections and insights of stakeholders’ point of view. Four clear requests became evident from the stakeholders responses: the application of modern innovative teaching methods; soft skills training; modern software applications training; and practical technical or industrial training.
Access to Empirical Formulations of Combustion Efficiency for Gas Turbine Combustors With Improved Generalization Ability
Authors: Ma Zhuang , Ji Tingwei , Cui Tao , Zheng Yao
Published: July 2020

Correlating combustion performance parameters to the main operating variables of combustors with mathematical expressions contributes to reducing the number of experiments and simplifying the design procedure of gas turbines. The application of empirical formulations meets the requirement with finite precision. The present study aims at adopting symbolic regression method to establish empirical formulations to correlate combustion efficiency with the main operating variables of gas turbine combustors. Differing from ordinary data modeling methods that search model parameters only with model structures fixed, symbolic regression method can search the structures and parameters of mathematical models simultaneously. In this article, attempts to correlate the experimental data of Combustor I using the mechanism model of burning velocity model, neural network, polynomial regression, and symbolic regression are shown sequentially. Burning velocity model has not satisfactory accuracy by comparing the predictions with the experimental data which means its lower generalization ability. Comparatively, the predictions of the empirical formulation obtained by the present symbolic regression method are in good agreement with the experimental data and also excel those of neural network and polynomial regression in generalization ability. Another two formulations are obtained by symbolic regression using the experimental data of Combustor II and III, and the different model structures of the two formulations indicate that there is still room for improvement in the present method.
A Numerical Investigation of Air/Mist Cooling Through a Conjugate, Rotating 3D Gas Turbine Blade With Internal, External, and Tip Cooling
Authors: Abdelmaksoud Ramy , Wang Ting
Published: July 2020

This paper describes a numerical investigation to study the effect of injecting mist (tiny water droplets) into the cooling air used to cool down rotating gas turbine blades. In this study, the conjugate heat transfer method is used which consists of the simulation of the air/mist fluid flow inside and outside the blades as well as the heat conduction through the blade body. The complete 3D blade with internal cooling passages and external film cooling holes on the surface and blade tip is simulated in a rotating, periodic sector of the blade. The discrete phase model (DPM) is used to simulate and track the evaporation and movement of the tiny water droplets. The rotation effect of the turbine blade is included in the computational fluid dynamics (CFD) simulation by using the moving reference frame method. The effects of different parameters such as the mist/air ratio (10–20%) and the mist droplets size (20–40 µm) on mist cooling enhancement are investigated. The results show that the mist cooling enhancements are about 10–25% on the outer surface of the blade and reach 50% in some locations inside the blade on the internal cooling passages walls. Most of the liquid droplets completely evaporate inside the internal cooling passages; only a limited amount of mist is able to escape from the film cooling holes to enhance the blade outer surface and blade tip cooling. The effect of 10% mist on enhanced cooling can be converted to an equivalent of a 30% reduction in cooling air flow.
An Experimentally Validated Model of a Cross-Flow Sub-Wet Bulb Evaporative Chiller
Authors: Yang Yahui , Narayanan Vinod , Pistochini Theresa , Ross Derrick
Published: July 2020

A simplified model to predict the performance of a novel sub-wet bulb evaporative chiller (SWEC) for producing chilled water is presented. The SWEC design uses a daisy-chained arrangement of cross-flow heat exchangers (HXs) with evaporative media located in between the heat exchangers to chill water below the outdoor wet bulb temperature (WB) in either a one-pass or two-pass arrangement. Sub-models, based on the effectiveness-number of transfer units (ɛ-NTU) method, for the heat exchanger and evaporative media are coupled together to form the SWEC model. The model is validated using field data from a SWEC that is designed with a single water pass. The model results are observed to match the SWEC experimental data within a mean average error (MAE) of 0.74% in supply chilled water temperature and 5.6% in chiller capacity over a range of outdoor air dry bulb and wet bulb temperatures, inlet water temperatures, and water flowrates. The validated model is then used in a parametric study of geometrical and thermofluidic variables. The model is also used to predict the performance of the SWEC in a typical hot and dry weather over a summer week.
Droplet Coalescence in Liquid/Liquid Separation
Authors: E. Weiwei , Pope Kevin , Duan Xili
Published: July 2020

In this paper, a new correlation is developed to predict liquid/liquid separation dynamics with a focus on a water/oil mixture. The correlation employs a force balance on the droplets to predict the rising velocity of the oil phase. The effect of droplet coalescence on the droplet's rising velocity is investigated, and the new correlation predicts the coalescence rate based on the oil/water volume fraction, as well as the initial droplet diameter. To develop the correlation for droplet coalescence, a series of new numerical simulations of a batch oil/water separation process were conducted. An equivalent experiment was conducted, the results of which agree well with the numerical predictions (relative error of 13.39%). The new correlation can predict the rate of separation with a relative error of 6.35% compared to numerical predictions.
Imperfect Bifurcation and Chaos of Slightly Curved Carbon Nanotube Conveying Hot Pressurized Fluid Resting on Foundations
Authors: Oyelade Akintoye O. , Oyediran Ayo A.
Published: July 2020

Unintended slight curvature of a straight pipe and temperature variation in a pipe has been found to create uncertainties in tubes and pipes. Fluttering, divergence, and chaotic instabilities of slightly curved carbon nanotubes (SCCNT) conveying hot pressurized fluid are investigated in this paper. The SCCNT is modeled on the basis of large deformation strains. Their gradients are included in the strain energy expression and the velocity and its gradients in the kinetic energy derivation. In modeling the size effects, both the static and kinetic length scales in the energy equations were considered. Governing equation is derived using Lagrangian approach. The effects of geometric imperfection (which leads to cusp bifurcation), small length scale, and kinetic material length parameter on the static and dynamic instability characteristics of the pipes are studied. Analysis is performed using the eigenfunction expansion method. It is found that the material length scale parameter increase tends to shift instability to the lower fluid velocity while the kinematic material length parameter increase does not change the buckling point but lowers the frequency. In the nonlinear dynamic case, both the parameters lead to chaos of the nanotube beyond the critical fluid velocity. The thermal loading changes the sudden supercritical pitchfork bifurcation to cusp bifurcation. The increasing linear and nonlinear foundation stiffness leads the system to chaotic features after the critical point.
Investigation on the Energy Exchange Characteristics of the Regenerative Flow Pump in an Automobile Fuel System
Authors: Li Qian-qian , Zhao Guo-shou , Wu Cheng-shuo , Wu Peng , Wu Da-zhuan , Guo Chun-lin
Published: July 2020

The flow inside the regenerative flow pump (RFP) is quite complex. This study investigated four pump models with various geometrical dimensions to explore the energy exchange characteristics. A computational fluids dynamics (CFD) simulation and the experiment were carried out. The results illustrate that the pressure growth mode in the impeller is consistent with the channels, which confirms the circulation flow existing in the pump. Furthermore, it is found that the circulation flow that features with longitudinal vortexes can be evaluated quantitatively by combining the analyses of the dimensionless axial distance, circulation number and entropy production. A smaller axial distance indicates that more flow is involved in the circulation and the intensity of the longitudinal vortex is enhanced; a large circulation number accompanied by a small dissipation loss could result in a satisfactory exchange flow. Therefore, the largest circulation number, least amount of dissipation, and shortest distance lead to the highest head and efficiency in the model with V-shaped blades and an increased impeller height. This work establishes a deeper understanding of the energy exchange mechanism and could serve as a reference for the geometrical design and performance reinforcement of RFP.
Relationship Between Flow Instability and Performance of a Centrifugal Pump With a Volute
Authors: Shim Hyeon-Seok , Kim Kwang-Yong
Published: July 2020

Flow instability and its correlations with performance characteristics were investigated for a centrifugal pump with a volute. Unsteady three-dimensional Reynolds-averaged Navier–Stokes analysis was performed to analyze the flow and performance characteristics using the shear stress transport (SST) turbulence model. The grid dependence and temporal resolution were tested to evaluate the numerical uncertainties, and the numerical solutions were validated using experimental data. The total-to-static head coefficient, the impeller's total-to-static head coefficient, and the volute static pressure recovery coefficient were selected as performance parameters. To identify the flow instability, pressure fluctuations were monitored upstream of the impeller, at the volute inlet, and on the shroud wall of the impeller. Three different types of flow instability were detected in partial-load conditions: inside the volute, upstream of the impeller, and at the interface between the impeller and volute. The time-dependent flow structures were investigated to obtain insight into the onset of the flow instability. The correlation of the onset of the flow instability with the performance curves was discussed.
Computational Study of the Effect of Homogeneous and Heterogeneous Bubbly Flows on Bulk Gas–Liquid Heat Transfer
Authors: Panicker Nithin S. , Passalacqua Alberto , Fox Rodney O.
Published: July 2020

A numerical investigation is performed on buoyancy-driven homogeneous and heterogeneous bubbly flows to compare the bulk gas–liquid heat transfer effectiveness for Prandtl (Pr) numbers 0.2–20 and void fractions 〈αg〉 0.3–0.5. For this purpose, transient two-fluid model simulations of bubbles rising in a stagnant pool of liquid are conducted in a rectangular box by applying periodic boundary conditions to all the sides. The temperature difference (ΔT) between gas and liquid phase is averaged over the rectangular box and monitored with respect to time, the heat transfer rate is studied based on the time at which the ΔT tends to zero. The results of numerical study show that at low Pr numbers, faster decay of ΔT is observed for homogeneous flow of bubbles indicating higher heat transfer rate in comparison with the heterogeneous flow of bubbles for the same void fraction. On the contrary, for high Pr numbers, higher heat transfer rate is observed in heterogeneous flow compared to the homogeneous. The comparison of heat transfer behavior between different void fractions for heterogeneous flow show that, for low Pr numbers higher heat transfer rate is achieved for void fraction 0.4 in comparison with void fraction 0.5. And for high Pr numbers, higher heat transfer is observed for void fraction 0.5 in comparison with void fraction 0.4.
Experimental and Numerical Investigation on the Influence of Thermally Induced Stress Gradients on Fatigue Life of the Nickel-Base Alloy Mar-M247
Authors: Thiele Marcus , Eckmann Stefan , Huang Min , Gampe Uwe , Fischer Kathrin A. , Schlesinger Michael
Published: July 2020

Today's and future parameters of stationary gas turbines and aircraft engines require intensive and highly efficient cooling of hot gas path components. High temperature and thermally induced stress gradients with impact on fatigue life are the consequence. Thermally induced stress gradients differ from geometrically induced stress gradients with respect to stress mechanics by the independence from external loads and material mechanics by the influence of temperature on material properties and strength. Regarding the contribution and evaluation on damage, the latter characteristic feature in turbomachinery is currently not fully understood. Therefore, a test facility has been designed, setup, and reported in GTP-18-1482 for the investigation of the influence of stationary temperature, and thus thermally induced stress gradients, on the damage evolution of cooled high-temperature components. To achieve high temperature and thermally induced stress gradients, large heat fluxes are required. A unique radiation heating has been developed allowing very high heat fluxes of q˙ ≥ 1.5 MW/m2 for testing of hollow cylindrical specimens. The conventional cast nickel-base alloy Mar-M247 has been chosen to study the influence of thermally induced stress gradients on fatigue life. The low-cycle fatigue testing of the hollow cylindrical specimens has been conducted both with and without superimposed stationary temperature gradients. In addition, complex low-cycle fatigue (CLCF) tests with symmetric and nonsymmetric loading conditions have been performed to provide the necessary database for the adaptation of a viscoplastic deformation model. To calculate the local stress–strain field and service life of the test specimens, linear elastic and viscoplastic finite element studies have been performed and were assessed by means of a fracture mechanics-based lifetime model. The test results show the considerable influence of the temperature gradient on the low-cycle fatigue life for the investigated material. Both the radial temperature variation over the specimen wall with a hot outer surface and a cooled inner surface as well as the thermally induced stresses are stated to be the main drivers for the change in low-cycle fatigue life. The test results enhance the understanding of fatigue-damage mechanisms under local unsteady conditions and can be used as a basis for improved service life predictions.
A homily on signal detection theory
Authors: Green David M.
Published: July 2020

A lifetime ago, as an undergraduate, I joined a team that developed a new way of thinking about the sensitivity of sensory systems. My teammates were Wilson (Spike) Tanner and John Swets, both now deceased, and we were working at the University of Michigan. I also wish to thank J.C.R. Licklider, J. P. Egan, and Lloyd Jeffress who aided and encouraged that development. I am gratified that what came to be called signal-detection theory (SDT) was so widely accepted and its methods so widely adopted. However, I am somewhat disappointed about how SDT commonly is portrayed, and taught. My reasons are presented here.
A time-scale modification dataset with subjective quality labels
Authors: Roberts Timothy , Paliwal Kuldip K.
Published: July 2020

Time Scale Modification (TSM) is a well-researched field; however, no effective objective measure of quality exists. This paper details the creation, subjective evaluation, and analysis of a dataset for use in the development of an objective measure of quality for TSM. Comprised of two parts, the training component contains 88 source files processed using six TSM methods at 10 time scales, while the testing component contains 20 source files processed using three additional methods at four time scales. The source material contains speech, solo harmonic and percussive instruments, sound effects, and a range of music genres. Ratings (42 529) were collected from 633 sessions using laboratory and remote collection methods. Analysis of results shows no correlation between age and quality of rating; expert and non-expert listeners to be equivalent; minor differences between participants with and without hearing issues; and minimal differences between testing modalities. A comparison of published objective measures and subjective scores shows the objective measures to be poor indicators of subjective quality. Initial results for a retrained objective measure of quality are presented with results approaching average root mean squared error loss and Pearson correlation values of subjective sessions. The labeled dataset is available at http://ieee-dataport.org/1987.
Insertion loss of a thin partition for audio sounds generated by a parametric array loudspeaker
Authors: Zhong Jiaxin , Wang Shuping , Kirby Ray , Qiu Xiaojun
Published: July 2020

Unlike the audio sound generated by traditional sources, the directivity of that generated by a parametric array loudspeaker (pal) deteriorates significantly after passing through a thin partition. To study this phenomenon, the pal radiation model based on the Westervelt equation, and the plane wave expansion method are used to calculate the sound fields behind a sheet of aluminum foil and a porous material blanket under the quasi-linear assumption, where the paraxial approximation is assumed only for ultrasonic waves. The audio sounds generated by a point monopole and a traditional directional source are presented for comparison. Both simulation and experiment results show that the transmitted sound from a pal behind the thin partition is small and less focused on the radiation axis because most of the ultrasounds forming the directivity of the pal is blocked by the thin partition which has little effect on the traditional audio sources.
Motion-Onset Visual Potentials Evoked in a Sport-Specific Visuomotor Reaction Task
Authors: Hülsdünker Thorben , Ostermann Martin , Mierau Andreas
Published: July 2020

Although neural visual processes play a crucial role in sport, experiments have been restricted to laboratory conditions lacking ecological validity. Therefore, this study examined the feasibility of measuring visual evoked potentials in a sport-specific visuomotor task. A total of 18 international elite young table tennis athletes (mean age 12.5 years) performed a computer-based and a sport-specific visuomotor reaction task in response to radial motion-onset stimuli on a computer screen and table tennis balls played by a ball machine, respectively. A 64-channel electroencephalography system identified the N2 and N2-r motion-onset visual evoked potentials in the motion-sensitive midtemporal visual area. Visual evoked potential amplitudes were highly correlated between conditions (N2 r = .72, N2-r r = .74) although significantly lower in the sport-specific task than in the lab-based task (N2 p < .001, N2-r p < .001). The results suggest that sport-specific visual stimulation is feasible to evoke visual potentials. This emphasizes the investigation of visual processes under more ecologically valid conditions in sport and exercise science.
Cancer cells with defective oxidative phosphorylation require endoplasmic reticulum–to–mitochondria Ca
2+
transfer for survival
Authors: Cardenas Cesar , Lovy Alenka , Silva-Pavez Eduardo , Urra Felix , Mizzoni Craig , Ahumada-Castro Ulises , Bustos Galdo , Jaňa Fabian , Cruz Pablo , Farias Paula , Mendoza Elizabeth , Huerta Hernan , Murgas Paola , Hunter Martin , Rios Melany , Cerda Oscar , Georgakoudi Irene , Zakarian Armen , Molgó Jordi , Foskett J. Kevin
Published: July 2020

Mitochondrial Ca
2+
influx promotes oxidative phosphorylation–independent pathways to enable cancer cell survival.
Untangling the ties that bind different systemic signals in plants
Authors: Fichman Yosef , Zandalinas Sara I. , Mittler Ron
Published: July 2020

Glutamate receptors integrate wound-induced signals to propagate systemic responses in plants (Shao
et al
., in 14 July 2020 issue).
Both Handwashing and an Alcohol-Based Hand Sanitizer Intervention Reduce Soil and Microbial Contamination on Farmworker Hands during Harvest, but Produce Type Matters
Authors: Prince-Guerra Jessica L. , Nace Molly E. , Lyles Robert H. , Fabiszewski de Aceituno Anna M. , Bartz Faith E. , Arbogast James W. , Gentry-Shields Jennifer , Jaykus Lee-Ann , Heredia Norma , García Santos , Leon Juan S.
Published: July 2020

This study demonstrated that the type of produce commodity handled influences the ability of handwashing with soap and water or a two-step alcohol-based hand sanitizer (ABHS) intervention to reduce soil and bacterial hand contamination. Handwashing with soap and water, as recommended by the FDA’s Produce Safety Rule, when tested in three agricultural environments, does not always reduce bacterial loads. Consistent with past results, we found that the two-step ABHS method performed similarly to handwashing with soap and water but also does not always reduce bacterial loads in these contexts. Given the ease of use of the two-step ABHS method, which may increase compliance, the two-step ABHS method should be further evaluated and possibly considered for implementation in the agricultural environment. Taken together, these results provide important information on hand hygiene effectiveness in three agricultural contexts.
Enterococcus faecalis Maltodextrin Gene Regulation by Combined Action of Maltose Gene Regulator MalR and Pleiotropic Regulator CcpA
Authors: Grand Maxime , Riboulet-Bisson Eliette , Deutscher Josef , Hartke Axel , Sauvageot Nicolas
Published: July 2020

Enterococcus faecalis
represents a leading cause of hospital-acquired infections worldwide. Several studies highlighted the importance of carbohydrate metabolism in the infection process of this bacterium. The genes required for maltodextrin metabolism are particularly induced during mouse infection and, therefore, should play an important role for pathogenesis. Since no data were hitherto available concerning the regulation of expression of the maltodextrin operons, we have conducted experiments to study the underlying mechanisms.
Vaginal Tampon Colonization by Staphylococcus aureus in Healthy Women
Authors: Chiaruzzi Myriam , Barbry Alexia , Muggeo Anaëlle , Tristan Anne , Jacquemond Isaline , Badiou Cedric , Cluzeau Laurence , Bourdeau Sabine , Durand Thibaut , Engelmann Astrid , Bosquet Dorian , Bes Michèle , Prigent-Combaret Claire , Thioulouse Jean , Muller Daniel , Lina Gérard
Published: July 2020

Menstrual toxic shock syndrome (MTSS) is an uncommon severe acute disease that occurs in healthy menstruating women colonized by TSST-1-producing
S. aureus
who use intravaginal protection, such as tampons and menstrual cups. The catamenial product collected by the protection serves as a growth medium for
S. aureus
and allows TSST-1 production. Previous studies evaluated the prevalence of genital colonization by
S. aureus
by vaginal swabbing, but they did not examine tampon colonization. This study demonstrated a high prevalence of tampon colonization by
S. aureus
and the presence of the CC30 TSST-1
S. aureus
clone responsible for MTSS in tampons from healthy women. The results support the vaginal carriage of this lineage in healthy women. In addition, the higher prevalence of
S. aureus
within tampons that do not require an applicator indicates a crucial role for handwashing before tampon handling to decrease the risk of tampon contamination.
Metabolic Syndrome and Viral Pathogenesis: Lessons from Influenza and Coronaviruses
Authors: Smith Maria , Honce Rebekah , Schultz-Cherry Stacey
Published: July 2020

Metabolic syndrome increases the risk of severe disease due to viral infection. Yet few studies have assessed the pathogenesis of respiratory viruses in high-risk populations. Here, we summarize how metabolic dysregulation impairs immune responses, and we define the role of metabolism during influenza virus and coronavirus infections. We also discuss the use of various
in vitro
,
in vivo
, and
ex vivo
models to elucidate the contributions of host factors to viral susceptibility, immunity, and disease severity.
Arcuate thrust systems in sandbox experiments: A comparison to the external arcs of the Western Alps
Authors: Lickorish W.H. , Ford M. , Bürgisser J. , Cobbold P.R.
Published: July 2020

In the external Western Alps, two regional structural arcs were generated during Tertiary northwest-directed collision between the Apulian indenter and the European passive margin. These arcs, distinguished by their geographic position and their age, are examined by using a new compilation of structural data and comparing these to the results of sandbox-analogue experiments. The principal Western Alpine arc comprises two orthogonal, synchronous thrust systems. In the late Eocene–early Miocene, major shortening (105 km) was toward the northwest to west-northwest, and minor shortening (11 km) was toward the southwest. Shortening in each branch decreased toward the core of the arc. During the late Miocene and Pliocene, the Jura arc accommodated 35 km of northwest- directed shortening, while 10.5 km of southwest- to south-southwest–directed shortening was accommodated on the Digne thrust system.

Sandbox experiments were used to investigate the role of the motion vector of a rigid rectangular indenter (orthogonal, diagonal, curved, or rotational paths) and the mechanical stratigraphy of the foreland in the evolution of upper-crustal arcuate systems (e.g., presence of a basal easy-slip [silicone] horizon). Comparison of experimental results with the external Alpine arc suggests that the indenter followed a slightly diagonal path with respect to the European margin from the Eocene to the early Miocene and curved counterclockwise by 10°–15° in the middle Miocene. Mechanical stratigraphy experiments support the hypothesis that thick Triassic evaporites played a primary role in the evolution of the Jura arc. The influence of mechanical stratigraphy was most prominent during weak deformation at the external boundaries of the Alpine orogen (Jura fold-and-thrust belt, Digne thrust).
Numerical modeling of fluvial strath-terrace formation in response to oscillating climate
Authors: Hancock Gregory S. , Anderson Robert S.
Published: July 2020

Many river systems in western North America retain a fluvial strath-terrace rec ord of discontinuous downcutting into bedrock through the Quaternary. Their importance lies in their use to interpret climatic events in the headwaters and to determine long-term incision rates. Terrace formation has been ascribed to changes in sediment supply and/or water discharge produced by late Quaternary climatic fluctuations. We use a one-dimensional channel- evolution model to explore whether temporal variations in sediment and water discharge can generate terrace sequences. The model includes sediment transport, vertical bedrock erosion limited by alluvial cover, and lateral valley-wall erosion. We set limits on our modeling by using data collected from the terraced Wind River basin. Two types of experiments were performed: constant- period sinusoidal input histories and variable-period inputs scaled by the marine δ18O rec ord. Our simulations indicate that strath-terrace formation requires input variability that produces a changing ratio of vertical to lateral erosion rates. Straths are cut when the channel floor is protected from erosion by sediment and are abandoned—and terraces formed—when incision can resume following sediment-cover thinning. High sediment supply promotes wide valley floors that are abandoned as sediment supply decreases. In contrast, wide valleys are promoted by low effective water discharge and are abandoned as discharge increases. Widening of the valley floors that become terraces occurs over many thousands of years. The transition from valley widening to downcutting and terrace creation occurs in response to subtle input changes affecting local divergence of sediment-transport capacity. Formation of terraces lags by several thousand years the input changes that cause their formation.

Our results suggest that use of terrace ages to set limits on the timing of a specific event must be done with the knowledge that the system can take thousands of years to respond to a perturbation. The incision rate calculated in the field from the lowest terrace in these systems will likely be higher than the rate calculated by using older terraces, because the most recent fluvial response in the field is commonly downcutting associated with declining sediment input since the Last Glacial Maximum. This apparent increase in incision rates is observed in many river systems and should not necessarily be interpreted as a response to an increase in rock-uplift rate.
Familiarity with the clinical environment, achieved by priming, improves time to antibiotic administration in a simulated paediatric sepsis scenario: a randomised control trial
Authors: McNaughten Ben , Storey Lesley , Corkin Doris , Cardwell Pauline , Thompson Andrew , Bourke Thomas , O'Donoghue Dara
Published: July 2020

Aim

The early administration of antibiotics in sepsis reduces mortality and improves outcomes. This randomised control trial evaluated the effect of environmental priming (EP) on healthcare student performance in a simulated paediatric sepsis scenario.

Methods

Medical and nursing students were randomised into primed and unprimed groups. Primed groups received both direct and virtual priming. Each group completed a standardised simulated sepsis scenario. Time to achieve five key clinical interventions was recorded. Mini focus groups were conducted to explore perceptions of EP.

Results

There were 26 primed and 26 unprimed groups. The primed students were quicker to complete all five interventions and statistically significantly quicker to achieving intravenous (IV) access (median 350 s vs 373 s, p=0.02), administering IV antibiotics (median 648 s vs 760 s, p=0.045) and seeking senior help (median 703 s vs 780 s, p=0.02). Primed students did not feel that they had gained any specific advantage from being primed.

Conclusions

EP can improve clinical performance. Implications for practice include incorporating EP of key clinical areas into local induction, standardisation of resuscitation areas and regular use of in situ simulation.
Liver stiffness by transient elastography accompanies illness severity in COVID-19
Authors: Effenberger Maria , Grander Christoph , Fritsche Gernot , Bellmann-Weiler Rosa , Hartig Frank , Wildner Sophie , Seiwald Stefanie , Adolph Timon Erik , Zoller Heinz , Weiss Gunter , Tilg Herbert
Published: July 2020

Objective

Severe liver damage is associated with worse outcome in COVID-19. Our aim was to explore the degree of liver damage, liver stiffness (LS) and severity of illness in patients with COVID-19.

Design

We investigated 32 patients with COVID-19 admitted to the University Hospital of Innsbruck in a prospective cross-sectional study. We performed laboratory testing, liver and spleen sonography and elastography to measure organ stiffness.

Results

12 patients (38%) showed elevated aminotransferases and gamma-glutamyltransferase levels. LS was positively correlated with elevated aminotransferase levels in patients with COVID-19 compared with those without elevated enzymes. Even mild liver damage raised LS significantly in COVID-19 as it was in patients with gastrointestinal symptoms. Furthermore, higher LS measurements were significantly associated with illness severity like pneumonia, need for mechanical ventilation, and even death.

Conclusion

Transient elastography is a useful and non-invasive tool to assess onset and severity of acute liver injury in patients with COVID-19 patients. Increased LS seems to be predictive for a more severe and complicated course of disease.
Study protocol of the Health4Life initiative: a cluster randomised controlled trial of an eHealth school-based program targeting multiple lifestyle risk behaviours among young Australians
Authors: Teesson Maree , Champion Katrina E , Newton Nicola C , Kay-Lambkin Frances , Chapman Cath , Thornton Louise , Slade Tim , Sunderland Matthew , Mills Katherine , Gardner Lauren A , Parmenter Belinda , Lubans David R , Hides Leanne , McBride Nyanda , Allsop Steve , Spring Bonnie J , Smout Scarlett , Osman Bridie
Published: July 2020

Introduction

Lifestyle risk behaviours, including alcohol use, smoking, poor diet, physical inactivity, poor sleep (duration and/or quality) and sedentary recreational screen time (‘the Big 6’), are strong determinants of chronic disease. These behaviours often emerge during adolescence and co-occur. School-based interventions have the potential to address risk factors prior to the onset of disease, yet few eHealth school-based interventions target multiple behaviours concurrently. This paper describes the protocol of the Health4Life Initiative, an eHealth school-based intervention that concurrently addresses the Big 6 risk behaviours among secondary school students.

Methods and analysis

A multisite cluster randomised controlled trial will be conducted among year 7 students (11–13 years old) from 72 Australian schools. Stratified block randomisation will be used to assign schools to either the Health4Life intervention or an active control (health education as usual). Health4Life consists of (1) six web-based cartoon modules and accompanying activities delivered during health education (once per week for 6 weeks), and a smartphone application (universal prevention), and (2) additional app content, for students engaging in two or more risk behaviours when they are in years 8 and 9 (selective prevention). Students will complete online self-report questionnaires at baseline, post intervention, and 12, 24 and 36 months after baseline. Primary outcomes are consumption of sugar-sweetened beverages, moderate-to-vigorous physical activity, sleep duration, sedentary recreational screen time and uptake of alcohol and tobacco use.

Ethics and dissemination

This study has been approved by the University of Sydney (2018/882), NSW Department of Education (SERAP no. 2019006), University of Queensland (2019000037), Curtin University (HRE2019-0083) and relevant Catholic school committees. Results will be presented to schools and findings disseminated via peer-reviewed journals and scientific conferences. This will be the first evaluation of an eHealth intervention, spanning both universal and selective prevention, to simultaneously target six key lifestyle risk factors among adolescents.

Trial registration number

Australian New Zealand Clinical Trials Registry (ACTRN12619000431123), 18 March 2019.
Women’s experiences of the renewed National Cervical Screening Program in Australia 12 months following implementation: a qualitative study
Authors: Dodd Rachael H , Mac Olivia A , McCaffery Kirsten J
Published: July 2020

Objective

To explore women’s experiences of the renewed National Cervical Screening Program in Australia from the perspective of women who have received different human papillomavirus (HPV) test results. Women aged 25 to 74 are now screened every 5 years with primary HPV screening.

Design

Qualitative interview study.

Setting

Australia.

Participants

Women in Australia aged 25 to 74 who reported participating in cervical screening since December 2017, purposively sampled by test result (HPV positive, HPV negative and HPV status unknown).

Methods

26 interviews with women aged 25 to 74 were conducted and analysed thematically.

Results

Three main themes emerged: knowledge and attitudes about the programme changes, information dissemination, the meaning and responses to test results and the new cervical screening test (CST). Some women showed little awareness of the changes, but others understood that HPV is detected earlier than abnormal cells. Some expressed positive attitudes towards the CST and were not anxious about less frequent screening. Most women envisaged the changes would have minimal impact on their screening behaviour. Women mainly wanted more information about the changes and the possible results from the new CST. Overall women could recall their HPV results and understand the implications for future cervical screening. Anxiety about being at ‘increased risk’ was more apparent in women who were HPV positive without history of abnormal results.

Conclusions

Women show some understanding of HPV and the new CST, but more written and public communication about the changes and possible results are warranted. Efforts are needed to ensure that women who are HPV positive without history of abnormal results receive the information needed to alleviate anxiety.
Nutrition and physical activity professional education in gastrointestinal oncology: a national multidisciplinary survey
Authors: Hilmi Marc , Pellat Anna , Benoit Olivier , Foucaut Aude-Marie , Mino Jean-Christophe , Kauffmann Agnes , Rochet Fanny , Heuze Emmanuel , Pudlarz Thomas , Naoun Natacha , Garcia-Larnicol Marie-Line , Delpeut Christine , Peschaud Frederique , Neuzillet Cindy
Published: July 2020

Objectives

Sarcopenia, present in more than 50% of digestive oncology patients, has a negative impact on clinical outcomes. Nutrition and adapted physical activity are two major interventions for the management of sarcopenia. However, young hepato-gastroenterologists, oncologists and surgeons in France have limited awareness on these topics. We aimed to evaluate the need for training programmes of physicians (residents and senior doctors) involved in digestive oncology on nutrition and adapted physical activity.

Methods

A 42-question survey was developed, by a working group of clinicians, dieticians and adapted physical activity teachers, to assess five areas related to demographics of respondents, nutrition practices, nutrition training, adapted physical activity practices and adapted physical activity training. The national survey was undertaken between April and July of 2019.

Results

230 physicians participated in the survey; 34% were hepato-gastroenterologists, 31% were oncologists, 23% were surgeons and 40% were residents. Sixty-one per cent of participants had received training in nutrition and only 21% in adapted physical activity. Ninety per cent of the physicians expressed their desire for more effective training on these two topics. Disparities in clinical practices were observed between hepato-gastroenterologists, oncologists and surgeons.

Conclusions

More initial and continuing training on nutrition and adapted physical activity is needed for French physicians in the current digestive oncology clinical practice.
Cardiovascular disease in homeless versus housed individuals: a systematic review of observational and interventional studies
Authors: Al-Shakarchi Nader James , Evans Hannah , Luchenski Serena A , Story Alistair , Banerjee Amitava
Published: July 2020

Objectives

To identify: (i) risk of cardiovascular disease (CVD) in homeless versus housed individuals and (ii) interventions for CVD in homeless populations.

Methods

We conducted a systematic literature review in EMBASE until December 2018 using a search strategy for observational and interventional studies without restriction regarding languages or countries. Meta-analyses were conducted, where appropriate and possible. Outcome measures were all-cause and CVD mortality, and morbidity.

Results

Our search identified 17 articles (6 case-control, 11 cohort) concerning risk of CVD and none regarding specific interventions. Nine were included to perform a meta-analysis. The majority (13/17, 76.4%) were high quality and all were based in Europe or North America, including 765 459 individuals, of whom 32 721 were homeless. 12/17 studies were pre-2011. Homeless individuals were more likely to have CVD than non-homeless individuals (pooled OR 2.96; 95% CI 2.80 to 3.13; p<0.0001; heterogeneity p<0.0001; I2=99.1%) and had increased CVD mortality (age-standardised mortality ratio range: 2.6–6.4). Compared with non-homeless individuals, hypertension was more likely in homeless people (pooled OR 1.38–1.75, p=0.0070; heterogeneity p=0.935; I2=0.0%).

Conclusions

Homeless people have an approximately three times greater risk of CVD and an increased CVD mortality. However, there are no studies of specific pathways/interventions for CVD in this population. Future research should consider design and evaluation of tailored interventions or integrating CVD into existing interventions.
Patterns of gun owner beliefs about firearm risk in relation to firearm storage: a latent class analysis using the 2019 National Firearms Survey
Authors: Salhi Carmel , Azrael Deborah , Miller Matthew
Published: July 2020

Background

Research on gun owners’ risk-related beliefs has focused on how gun owners answer discrete questions about firearm risk. The current study is the first to use latent class analysis (LCA) to: (A) identify groups of gun owners who share patterns of beliefs about firearm-related risk and (B) examine whether class membership predicts household firearm storage.

Methods

We conducted LCA using the 2019 National Firearms Survey, a nationally representative survey of US adult gun-owners (n=2950). The LCA assigned gun owners to classes based on responses to four questions about firearm-related risk. Identified classes were included in logistic regression models predicting firearm storage, along with characteristics linked to storage in past research.

Results

Three classes emerged: (1) owners who believe that guns unconditionally make the home safer and should generally be readily accessible (47%); (2) owners who believe that whether guns make homes safer or less safe depends on context (34%); (3) owners who believe that guns do not pose a risk if stored safely (19%). In adjusted models, compared with owners in class 1, those in classes 2 and 3 were less likely to store guns loaded and unlocked (class 2: OR 0.30, 95% CI 0.23 to 0.39; class 3: OR 0.23, 95% CI 0.16 to 0.32).

Conclusion

Our LCA is a first step towards better understanding variation in patterns of beliefs among gun owners regarding the risks and benefits of firearms. Our results suggest that messaging aimed at promoting safer firearms storage might benefit from the empirically derived typologies we identify.
Leveraging naturally occurring variation in financial stress to examine associations with inflammatory burden among older adults
Authors: Samuel Laura , Szanton Sarah L , Fedarko Neal S , Simonsick Eleanor M
Published: July 2020

Background

Financial strain is associated with earlier disability and mortality, but causal links are underexplored, partly because it is unethical to randomise people to financial stress. This study leverages naturally occurring random variation in days since monthly Social Security payment arrival among older adults to test associations with inflammatory biomarkers.

Methods

Biomarker data, including tumour necrosis factor (TNF)-α, interleukin (IL)-6 and C reactive protein (CRP), was collected from 2155 non-working healthy adults aged 70–79 years, participating in the Health, Aging and Body Composition Study. Days since payment arrival was independent of all demographic, socioeconomic or health characteristics measured in this study. Restricted cubic spline models estimated associations separately for each week of the month, stratified by financial strain status (interaction term p value for TNF-α model <0.05).

Results

Among financially strained older adults, more days since payment arrival was associated with higher TNF-α levels during the first week of the month (coefficient=0.102). Associations with IL-6 and CRP differed depending on the degree of financial strain (interaction term p values <0.05). Those with low, but not high, strain had lower levels of IL-6 (coefficient=−0.152) and CRP (coefficient=−0.179) during the first week.

Conclusions

Days since monthly payments were associated with inflammatory cytokines among older adults who have difficulty making ends meet financially and associations depended on financial strain severity, suggesting that results are attributable to monthly variation in financial stress. Future research should examine whether more frequent Social Security disbursement would modify financial strain and inflammatory biomarkers.