bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond clinical trials: Extending the role of the clinical research nurse into social care and homeless research
Authors: Biswell R Elizabeth , Clark Michael , Tinelli Michela , Manthorpe Gillian , Neale Joanne , Whiteford Martin , Cornes Michelle
Published: June 2021

Aim

Clinical research nurses work at the fulcrum of clinical trials with clearly defined roles and responsibilities. In England, the National Institute for Health Research (the main funder of health research) has broadened its scope to encompass social care research. The expectation is that clinical research nurses will expand their skill set to support these new studies, many of which will employ qualitative and mixed methods. This discussion paper explores the challenges of facilitating this clinical academic workforce development through a case study of a homeless health and social care research project. This was one of the first studies to engage clinical research nurses in this new and expanded role.

Background

Much of what is known about the research nurse workforce has been generated through studies of clinical trials in oncology. The ‘caring‐recruiting’ dichotomy has been used as a heuristic device for identifying workforce issues that can impact on study delivery such as how intense pressure to recruit study participants leads to low job satisfaction.

Design

This case study reflects on the authors' experiences of employing a clinical research nurse in a social care research project concerned with the discharge of homeless people from hospital. The ‘caring‐recruiting’ dichotomy is used to generate new information about the relationship between workforce development and the successful delivery of social care research.

Conclusion

The case study illuminates how social care research can generate different pressures and ethical challenges for research nurses. The time and skill it took to recruit study participants identified as ‘hard to reach’ was suggestive of the need to move beyond performance measures that prioritise recruitment metrics. The need for different types of staff supervision and training was also warranted as supporting study participants who were homeless was often distressing, leading to professional boundary issues.

Relevance to workforce development

This study highlights that performance management, training and supervisory arrangements must be tailored to the characteristics of each new study coming onto the portfolio to ensure research nurses are fully supported in this new and expanded role.
Decellularized matrix could affect the proliferation and differentiation of periodontal ligament stem cells in vitro
Authors: Huang Jia‐Ping , Wu Yan‐Min , Liu Jia‐Mei , Zhang Lan , Li Bo‐Xiu , Chen Li‐Li , Ding Pei‐Hui , Tan Jing‐Yi
Published: June 2021

Objective and Background

Recently, decellularized matrix (DCM) is considered as a new biomaterial for tissue regeneration. To explore the possible application of DCM in periodontal regeneration, the effect of DCM from three different cells on the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs) was investigated.

Methods

DCM derived from human periodontal ligament cells (PDLCs), dental pulp cells (DPCs), and gingival fibroblasts (GFs) were fabricated using Triton X‐100/NH4OH combined with DNase I. Allogeneic PDLSCs were cultured on PDLC‐DCM, DPC‐DCM, and GF‐DCM, respectively. The proliferative capacity of PDLSCs was evaluated by PicoGreen assay kit. The expression of alkaline phosphatase (ALP), runt‐related transcription factor‐2 (RUNX2), osteocalcin (OCN), collagen I (COL1), periostin (POSTN), and cementum protein 1 (CEMP1) were detected by qRT‐PCR and western blotting.

Results

PDLC‐DCM, DPC‐DCM, and GF‐DCM had similar and integrated networks of extracellular matrix, as well as significantly decreased DNA content. Compared with control group in which PDLSCs were directly seeded in culture plates, PDLC‐DCM, DPC‐DCM, and GF‐DCM promoted the proliferation of re‐seeded PDLSCs. Additionally, PDLSCs on DCM exhibited higher mRNA and protein expression levels of ALP, RUNX2, OCN, and COL1. The expression of POSTN in PDLC‐DCM group was significantly higher than control group at both mRNA and protein levels.

Conclusions

PDLC‐DCM, DPC‐DCM, and GF‐DCM could enhance the proliferation of PDLSCs. PDLC‐DCM facilitated osteogenic differentiation and periodontal ligament differentiation of PDLSCs, while DPC‐DCM and GF‐DCM promoted osteogenic differentiation.
Multidose pharmacokinetics and safety of a modified, compounded theophylline product in dogs
Authors: Reinhart Jennifer M. , Perkowski Claudia , Lester Courtney , Campos Valeria , Kadotani Saki , Li Zhong , McKiernan Brendan C. , Fries Ryan
Published: June 2021

Theophylline is used in canine medicine for the management of chronic bronchitis and bradyarrhythmias, yet no species‐validated commercial products are available. This study reports the single‐dose and multidose pharmacokinetics and safety of a modified, compounded theophylline (MCT) product readily available from a well‐established, USP‐compliant compounding pharmacy, which may be a suitable and reliable source for theophylline for dogs. Eleven dogs underwent serial plasma theophylline measurement following 10 mg/kg MCT PO. After a 7 days washout, dogs received 10 mg/kg MCT PO q12h and serial plasma theophylline quantification was repeated after the ninth dose. Dogs were monitored for potential adverse effects. For the nine dogs that completed the study, plasma theophylline concentrations were between 5 and 30 μg/ml for 91 +/− 15% of the dosing interval. There was no significant difference in half‐life between single‐dose and multidose administration. The most common adverse effects reported were mild and included agitation, excitement, and increased activity. The results of this study support the use of 10 mg/kg MCT administered twice daily as a starting dosage in dogs. This regimen appears safe, achieves appropriate plasma drug concentrations in most dogs, and does not cause significant changes in pharmacokinetic properties at steady state. Because compounded drugs do not undergo consistent testing for identity, quality, strength, purity, and stability, results of research described in reports using compounded products may not be reproducible.
Support for the adaptive decoupling hypothesis from whole‐transcriptome profiles of a hypermetamorphic and sexually dimorphic insect, Neodiprion lecontei
Authors: Herrig Danielle K. , Vertacnik Kim L. , Kohrs Anna R. , Linnen Catherine R.
Published: June 2021

Though seemingly bizarre, the dramatic morphological and ecological transformation that occurs when immature life stages metamorphose into reproductive adults is one of the most successful developmental strategies on the planet. The adaptive decoupling hypothesis (ADH) proposes that metamorphosis is an adaptation for breaking developmental links between traits expressed in different life stages, thereby facilitating their independent evolution when exposed to opposing selection pressures. Here, we draw inspiration from the ADH to develop a conceptual framework for understanding changes in gene expression across ontogeny. We hypothesized that patterns of stage‐biased and sex‐biased gene expression are the product of both decoupling mechanisms and selection history. To test this hypothesis, we characterized transcriptome‐wide patterns of gene‐expression traits for three ecologically distinct larval stages (all male) and adult males and females of a hypermetamorphic insect (Neodiprion lecontei). We found that stage‐biased gene expression was most pronounced between larval and adult males, which is consistent with the ADH. However, even in the absence of a metamorphic transition, considerable stage‐biased expression was observed among morphologically and behaviourally distinct larval stages. Stage‐biased expression was also observed across ecologically relevant Gene Ontology categories and genes, highlighting the role of ecology in shaping patterns of gene expression. We also found that the magnitude and prevalence of stage‐biased expression far exceeded adult sex‐biased expression. Overall, our results highlight how the ADH can shed light on transcriptome‐wide patterns of gene expression in organisms with complex life cycles. For maximal insight, detailed knowledge of organismal ecology is also essential.
Abstraction and analogy‐making in artificial intelligence
Authors: Mitchell Melanie
Published: June 2021

Conceptual abstraction and analogy‐making are key abilities underlying humans' abilities to learn, reason, and robustly adapt their knowledge to new domains. Despite a long history of research on constructing artificial intelligence (AI) systems with these abilities, no current AI system is anywhere close to a capability of forming humanlike abstractions or analogies. This paper reviews the advantages and limitations of several approaches toward this goal, including symbolic methods, deep learning, and probabilistic program induction. The paper concludes with several proposals for designing challenge tasks and evaluation measures in order to make quantifiable and generalizable progress in this area.
Role of experimental periodontitis in inducing pulmonary inflammation in mice
Authors: Tian Huan , Zhang Zheng , Wang Xueyuan , Liu Wenyan , Wang Zuomin
Published: June 2021

Objective

The aim of the study was to explore the potential role of experimental periodontitis in pulmonary inflammation in mice.

Materials and methods

Mice were divided into control, ligature‐induced periodontitis (L) and ligature plus Porphyromonas gingivalis (P. gingivalis)‐induced periodontitis (LPG) groups. Alveolar bone resorption, pulmonary function, lung tissue histology and cytokine expression were examined at 2, 4 and 8 weeks. Then cytokines and neutrophils in the peripheral blood and lung tissue were further assessed at 8 weeks to determine the role of cytokines induced by LPG periodontitis, and the effect of P. gingivalis was evaluated using P. gingivalis‐IgG and P. gingivalis gingipain.

Results

Alveolar bone resorption was more severe in the L and LPG groups. However, pulmonary inflammation was observed only in the LPG group at 8 weeks when cytokines and neutrophils in the peripheral blood and lung tissue were the most significant elevation, along with higher levels of P. gingivalis‐IgG and P. gingivalis gingipain. Cytokine levels were also increased in the gingival tissue, peripheral blood and lung tissue in the L group, accompanied by elevated peripheral blood neutrophils, but not as significantly as that in the LPG group.

Conclusions

LPG periodontitis can trigger pulmonary inflammation over the long term, in which cytokines and P. gingivalis play an important role.
Validation of the Ramsay scale for invasive procedures under deep sedation in pediatrics
Authors: Lozano‐Díaz David , Valdivielso Serna Alberto , Garrido Palomo Ramón , Arias‐Arias Ángel , Tárraga López Pedro J. , Martínez Gutiérrez Andrés
Published: June 2021

Background

The Ramsay scale is the most widely used scale during pediatric procedures although it has not been formally validated.

Objective

To validate the Ramsay scale during invasive procedures under sedation in pediatrics.

Methods

A prospective analytic study was conducted in two hospitals. All patients ≥6 months that were undergoing invasive procedures under sedation were enrolled. All were recorded, and these videos were edited and randomized. 150 videos were scored by four observers (a pediatrician, a pediatric intensive care unit nurse, an anesthetist, and an operating room nurse). All videos were scored with the Ramsay scale and University of Michigan Sedation Scale. Observers were blinded to drug administration. Construct validity was measured through Wilcoxon test paired samples after administration of sedatives. Criterion validity, intra‐observer reliability, and interobserver correlation were evaluated by comparing the scores of the scales using Spearman’s correlation coefficient. Interobserver agreement was measured using the intraclass correlation coefficient. To assess test‐retest reliability, 50 videos were randomly selected and reevaluated.

Results

Sixty‐five patients were included. Construct validity was demonstrated through changes in the Ramsay scale scoring after administration of sedatives (p < .0001). Regarding criterion validity, the Ramsay scale had a high correlation with the UMSS (ρ = 0.621). Intra‐observer agreement was ρ = 0.884. The Ramsay scale showed interobserver reliability with an intraclass correlation coefficient = 0.94 when comparing it with the University of Michigan Sedation Scale. Internal consistency was α = 0.91. Regarding applicability, in our study, it was applied in two hospitals in different areas by four professionals from distinct categories.

Conclusions

The Ramsay scale is valid, reliable, and applicable to monitoring sedation for invasive procedures under deep sedation in pediatrics.
Differences in pediatric versus adult clinical trial characteristics for atopic dermatitis
Authors: Agnihotri Gaurav , Lio Peter A. , Lee Kachiu C.
Published: June 2021

Background

Atopic dermatitis (AD) is a growing burden in all ages. The aim of this study was to compare trial characteristics between pediatric and adult AD trials.

Methods

Data were collected from ClinicalTrials.gov on AD therapeutic trials completed between 2003 and 2019. The trials were classified as pediatrics (mean or median age <18 years of the experimental group participants) or adults. The trials with and without results on ClinicalTrials.gov were searched on PubMed for further data collection.

Results

Of 210 trials, 50 (24%) were pediatric trials [mean age: 8.2 ± 4.3 years (SD)] and 160 (76%) were adult trials [mean age 35.2 ± 5.7 years (SD)]. Pediatric and adult trials were equally likely to be randomized controlled trials; however, pediatric trials were more likely to be open‐label trials (P < .001) and have no comparator (P < .001). Adult trials were more likely to be industry‐funded (95% vs. 80%, P = .001). Any evaluation of drug safety was more likely present in adult trials (83% vs. 60%, P = .001). In trials examining AD severity as an outcome, the Eczema Area and Severity Index (EASI) predominated in adult trials (51% vs. 29%, P < .05) and Scoring Atopic Dermatitis (SCORAD) in pediatric trials (25% vs. 10%, P < .05).

Conclusion

The results highlight differences in trial design between pediatric and adult AD trials and show a lack of standardization in trial design.
Female advantage in gynodioecious plants: A meta‐analysis focused on seed quality
Authors: Varga S.
Published: June 2021

In gynodioecious systems, female plants must counteract the selective disadvantage of not passing genes via pollen production, as hermaphrodites can. Theory predicts that females must produce more or better‐quality seeds than hermaphrodites in order to be maintained within the same population. This female advantage has been widely measured and reported for seed number, but whether female advantage is gained through the production of better seeds remains relatively under‐studied.

Here, a meta‐analysis approach was used to investigate whether females in gynodioecious species produce seeds of better quality than hermaphrodites (measured as seed mass, seed nutrient content, seed germinability and seedling survival and performance) in addition to achieving a larger seed production. In total, 50 studies were included, reporting traits for 34 gynodioecious species in 17 different families.

Female advantage was significant for seed number and seed germination, but was not detected for seed mass, seed nutrient content or seedling performance.

A female advantage in seed number was corroborated in this meta‐analysis, which together with better seed germination, may explain maintenance of female plants within gynodioecious populations.
Ghrelin antagonist D‐Lys3‐GHRP‐6 counteract ghrelin effects in bovine cumulus‐oocytes complexes matured in vitro
Authors: Carranza‐Martín Ana C. , Nikoloff Noelia , Anchordoquy J. Patricio , Anchordoquy J. Mateo , Relling Alejandro E. , Furnus Cecilia C.
Published: June 2021

Ghrelin is a gut hormone related to energy balance and reproductive functions. The aim of this study was to evaluate the effect of ghrelin antagonist D‐Lys3‐GHRP‐6 (GA) as a potential agent that prevents ghrelin effects during bovine oocyte maturation on progesterone production, cumulus cell (CC) viability, CC DNA damage and embryo development and hatching rates. Ghrelin's potential to induce oxidative stress in cumulus‐oocyte complexes (COC) was also evaluated. COCs were cultured for 24 hr in medium without supplementation (C) or supplemented with 60 pM ghrelin (Ghrelin60), Ghrelin60 + 20 pM GA (GA20), Ghrelin60 + 60 pM GA (GA60) or Ghrelin60 + 100 pM GA (GA100) for experiment I. For experiment II, C and Ghrelin60 treatments were used. Differences between C and Ghrelin60 and the linear or quadratic association between GAs on Ghrelin60 were evaluated. Results demonstrated that Ghrelin60 increased progesterone concentration, reduced CC viability, induced CC DNA damage and decreased blastocyst and hatching rate compared with C (p < .05). GA20, GA60 and GA100 had a linear effect on CC genetic damage index (p ≤ .05) and a quadratic effect on CC viability (p < .01). GA20 counteracted the low hatching rate produced by Ghrelin60. However, GAs did not counteract progesterone concentration and blastocyst rate (p ≥ .21). GRH60 did not differ from C in the oxidative status (p ≥ .19). Our study highlights that GA could prevent the negative effects of ghrelin during bovine IVM.
Late Quaternary sedimentary evolution of the distal Galician continental margin (north‐west Iberian Peninsula) based on palaeoclimatic, palaeoproductivity and diagenetic evidence
Authors: López‐Pérez Ángel Enrique , Rubio Belén , Rey Daniel , Plaza‐Morlote Maider
Published: June 2021

Deep‐sea sediments record palaeoenvironmental and oceanographic changes over time through variations in their magnetochemical and sedimentological properties. This study presents the Late Quaternary sedimentary reconstruction of three sediment cores extracted from a source‐to‐sink sedimentary system located in a high marginal platform of the north‐west Iberian Margin. The aim of this reconstruction is to explore the palaeoclimatic, palaeoproductivity and diagenetic changes over the last 172 cal ka bp attending to geochemical, magnetic and sedimentological variations. The record is comprised of four sedimentary units consisting of pelagic, hemipelagic and detrital facies, the latter associated with ice‐rafted debris events at Heinrich Stadials. These findings allowed the reconstruction of the lithostratigraphy attending to climatic changes, covering the last eleven Heinrich Stadials. These units and facies successions are controlled by the superposition of the Milankovitch and Dansgaard–Oeschger cycles. Low sedimentation rates have been reported, especially during cold periods. Palaeoproductivity was assessed using total organic carbon and calcium carbonate content, together with biogenic barium (Babio) and organic phosphorus (Porg), both calculated via total digestion analysis using standard calculations. Mass accumulation rates for total organic carbon, Babio and Porg were calculated. Furthermore, a sequential extraction was performed to explore the different phases of the barium within sediments: biogenic barite (Babar), barium associated with iron and manganese oxides (Baox) and Ba associated with aluminosilicates (Badet). Results display a limitation in the use of the biogenic barium and phosphorus and mass accumulation rates, suggesting detrital Ba (Badetr) contribution during Heinrich Stadials, which could mask the calculations. In contrast, only calcium carbonate fluctuates attending to glacial/interglacial cycles. Regarding some diagenetic proxies (i.e. Mn, Mn/Fe and Mn/Ti), they reveal oxidation fronts of different generations, suggesting that the early diagenesis has not reached steady‐state, because the redoxcline fluctuates. This fact suggests an erosional activity that causes the continuous oxygenation of the sediment and non‐steady‐state conditions.
Applying the trans‐contextual model to promote sport injury prevention behaviors among secondary school students
Authors: Lee Alfred S. Y. , Standage Martyn , Hagger Martin S. , Chan Derwin K. C.
Published: June 2021

The current study tested the effects of an intervention based on the trans‐contextual model (TCM) on secondary school PE students’ sport injury prevention behavior and on theory‐based motivational and social cognition mediators. Participants were PE students (N = 1168; Mage = 13.322 ± 1.045, range = 12–16; female = 51.721%) who participated in a 3‐month cluster‐randomized controlled trial. Schools were randomly assigned to a treatment group, in which PE teachers received training to be more supportive of psychological needs in teaching sport injury prevention, or a control group, in which PE teachers received no training. Participants completed survey measures of TCM variables and self‐reported sport injury prevention behavior at baseline and at 3‐month post‐intervention follow‐up. The proposed TCM model exhibited adequate fit with the data, χ2 = 143.080 (df = 19), CFI = 0.956, TLI = 0.916, RMSEA = 0.078 (90% CI = 0.066–0.090), and SRMR = 0.058. We found positive, statistically significant direct intervention effects on changes in perceived psychological need support (β = 0.064, p = 0.020). We also found positive, significant direct (β = 0.086–0.599, p < 0.001) and indirect (β = 0.002–0.027, p = 0.020–0.032) intervention effects on changes in TCM variables and behaviors to prevent sport injuries. Our findings support the TCM as a useful framework for building an intervention for promoting sport injury prevention behaviors among secondary school students.
Teaching statistics and data science in England's schools
Authors: Davies Neville , Sheldon Neil
Published: June 2021

In 2003, Holmes [The Statistician 52, Part 4, (2003), 439–474] reviewed 50 years of teaching statistics in English schools and drew out many lessons for more effective teaching. We consider the current relevance of several of these lessons and whether we have learned from them. Many national reports have been published about teaching statistics with few of their recommendations being implemented. There have been rapid developments in the methodology of, and technology used by, statistics at all levels outside schools. These have led to the accelerated development of the use of statistics and related disciplines such as data science (DS). In schools, we have not seen as much progress in teaching, learning, assessing, or communicating these subjects. We consider reasons for lack of progress in pedagogy and make our own recommendations to get schools to catch up with the exciting developments in the practice and communication of statistics and DS.
When Fear Shrinks the Brain: A Computational Model of the Effects of Posttraumatic Stress on Hippocampal Volume
Authors: Smith Briana M. , Thomasson Madison , Yang Yuxue Cher , Sibert Catherine , Stocco Andrea
Published: June 2021

Post‐traumatic stress disorder (PTSD) is a psychiatric disorder often characterized by the unwanted re‐experiencing of a traumatic event through nightmares, flashbacks, and/or intrusive memories. This paper presents a neurocomputational model using the ACT‐R cognitive architecture that simulates intrusive memory retrieval following a potentially traumatic event (PTE) and predicts hippocampal volume changes observed in PTSD. Memory intrusions were captured in the ACT‐R rational analysis framework by weighting the posterior probability of re‐encoding traumatic events into memory with an emotional intensity termIto capture the degree to which an event was perceived as dangerous or traumatic. It is hypothesized that (1) increasing the intensityIof a PTE will increase the odds of memory intrusions, and (2) increased frequency of intrusions will result in a concurrent decrease in hippocampal size. A series of simulations were run and it was found thatIhad a significant effect on the probability of experiencing traumatic memory intrusions following a PTE. The model also found thatIwas a significant predictor of hippocampal volume reduction, where the mean and range of simulated volume loss match results of existing meta‐analyses. The authors believe that this is the first model to both describe traumatic memory retrieval and provide a mechanistic account of changes in hippocampal volume, capturing one plausible link between PTSD and hippocampal volume.
Self-Induced Vibrations
Authors: Baker J. G.
Published: June 2021

A “self-induced” vibration is defined as a phenomenon in which the alternating forces furnishing the energy to the vibration are controlled by the motion, in contradistinction to a “forced” vibration, where the force depends on time only. The following are examples of self-induced vibrations: (1) All bowed string or blown musical instruments, (2) the vacuum-tube oscillator, (3) fluttering of valves in air or water lines, (4) nosing of locomotives and street cars, (5) airplane-wing flutter, (6) certain cases of hunting of generators, and (7) certain cases of vibration of transmission lines due to wind. In physics and electrical engineering self-induced vibrations are common and often very useful, whereas most mechanical or machinery vibrations do not fall in this classification, since unbalance forces and other alternating forces unaffected by the motion are very common. Kimball and Newkirk were the first to call attention to and to explain self-induced vibration phenomena capable of causing serious mechanical difficulties. This paper discusses methods of studying self-induced vibrations and describes several representative cases that have been studied by the author and his colleagues in the last few years.
Analysis of Stresses in an Elliptic Ring
Authors: White Merit P.
Published: June 2021

Problems sometimes confront engineers the analytic solution of which requires quite a knowledge of mathematics. The author illustrates this with the calculations required in an investigation of a wind-tunnel problem. The method used is intricate and tedious. A simpler solution may be arrived at by use of the graphical method.
Response Effects Due to Polygonal Representation of Pores in Porous Media Thermal Models
Authors: Irick Kevin W. , Fathi Nima
Published: June 2021

Physics models — such as thermal, structural, and fluid models — of engineering systems often incorporate a geometric aspect such that the model resembles the shape of the true system that it represents. However, the physical domain of the model is only a geometric representation of the true system, where geometric features are often simplified for convenience in model construction and to avoid added computational expense to running simulations. The process of simplifying or neglecting different aspects of the system geometry is sometimes referred to as “defeaturing.” Typically, modelers will choose to remove small features from the system model, such as fillets, holes, and fasteners. This simplification process can introduce inherent error into the computational model.Asimilar event can even take place when a computational mesh is generated, where smooth, curved features are represented by jagged, sharp geometries. The geometric representation and feature fidelity in a model can play a significant role in a corresponding simulation’s computational solution. In this paper, a porous material system — represented by a single porous unit cell — is considered. The system of interest is a two-dimensional square cell with a centered circular pore, ranging in porosity from 1% to 78%. However, the circular pore was represented geometrically by a series of regular polygons with number of sides ranging from 3 to 100. The system response quantity under investigation was the dimensionless effective thermal conductivity, k*, of the porous unit cell. The results show significant change in the resulting k* value depending on the number of polygon sides used to represent the circular pore. In order to mitigate the convolution of discretization error with this type of model form error, a series of five systematically refined meshes was used for each pore representation. Using the finite element method (FEM), the heat equation was solved numerically across the porous unit cell domain. Code verification was performed using the Method of Manufactured Solutions (MMS) to assess the order of accuracy of the implemented FEM. Likewise, solution verification was performed to estimate the numerical uncertainty due to discretization in the problem of interest. Specifically, a modern grid convergence index (GCI) approach was employed to estimate the numerical uncertainty on the systematically refined meshes. The results of the analyses presented in this paper illustrate the importance of understanding the effects of geometric representation in engineering models and can help to predict some model form error introduced by the model geometry.
Discretization Error Estimation in Subsonic, Transonic and Supersonic Flows of an Inviscid Fluid Over a Bump
Authors: Eça Luís , Silva Cristiano , Muralha João , Klaij Christiaan , Toxopeus Serge , Hoekstra Martin
Published: June 2021

This paper presents a solution verification exercise for the simulation of subsonic, transonic and supersonic flows of an inviscid fluid over a circular arc (bump). Numerical simulations are performed with a pressure-based, single-phase compressible flow solver. Sets of geometrically similar grids covering a wide range of refinement ratios have been generated. The goal of these grids is twofold: obtain a reference solution from power series expansion fits applied to the finest grids; check the numerical uncertainties obtained from coarse grids that do not guarantee monotonic convergence of the quantities of interest.

The results show that even with very fine grids it is not straightforward to define a reference solution from power series expansions. The level of discretization errors required to obtain reliable reference solutions implies iterative errors reduced to machine accuracy, which may be extremely time consuming even in two-dimensional inviscid flows. Quantitative assessment of the estimated uncertainties for coarse grids depends on the selected reference solution.
Asymmetrical Heat Distribution Pattern in Miniature Heat Sinks Due to Conjugate Heat Transfer
Authors: Pourghasemi Mahyar , Fathi Nima
Published: June 2021

Three-dimensional numerical simulations are performed to investigate the conjugate heat transfer of water within microchannel heat sinks. Validation process is performed through comparison between obtained numerical results and experimental data. The global deviation grid convergence index (GCI) is used to conduct solution verification and calculate observed order of accuracy. Conducted numerical analyses include hydraulic diameter range of 206–330 µm, aspect ratio of 1–4 and Reynolds numbers of 300 to 850. Heat is observed to distribute non-uniformly among microchannel side and bottom walls due to conjugate heat transfer. Results show that over 93% of heat is transferred to water through microchannel side walls at the aspect ratio of 4. It is observed that the heat distribution is more non-uniform destruction while microchannel aspect ratio gets larger.
Eating Behaviors Among Male Bodybuilders and Runners: Application of the Trans-Contextual Model of Motivation
Authors: Chaba Lisa , Scoffier-Mériaux Stéphanie , d’Arripe-Longueville Fabienne , Lentillon-Kaestner Vanessa
Published: June 2021

This article focuses on two popular sports that can put male athletes at risk of developing an eating disorder: bodybuilding and running. Bodybuilders concentrate on gaining muscle mass and runners on leaning body mass. Based on the trans-contextual model of motivation, this study aimed to better understand the psychological mechanisms underlying eating disorders in these athletes. In all, 272 male bodybuilders and 217 male runners completed measures of sport motivation, theory of planned behavior variables (i.e., attitude, subjective norm, perceived behavioral control, and intention to gain muscle mass/lean body mass), and eating disorders (dieting, control, and bulimia behaviors). The results revealed satisfactory fit indices for both samples. Autonomous and controlled motivations for sport were positively directly and indirectly related to eating disorders in these athletes. This motivational mechanism needs more in-depth investigation, and motivational profiles might help distinguish athletes with and without eating disorders.
Amping up HIV antibodies
Authors: Burton Dennis R.
Published: June 2021

High serum titers of neutralizing antibody can protect humans against HIV
FDA's green light, science's red light
Authors: Perlmutter Joel S.
Published: June 2021

Alzheimer's disease (AD) afflicts some 6 million Americans with progressive cognitive impairment and personal anguish while imposing a huge economic burden on society. Everyone wants to find a way to help slow or even halt this disease. But there will be no quick fix. Responding to mounting pressure, the United States Food and Drug Administration (FDA) jumped the gun by granting accelerated approval this month to Biogen's pricey, questionably effective, and possibly harmful new drug aducanumab—a decision supported by not one of the 11 members of the agency's Expert Advisory Committee. Even worse, the approval may divert funding into a therapeutic dead end and away from approaches that might actually work.
Increasing demand for school counselling through a lay counsellor-delivered classroom sensitisation intervention: a stepped-wedge cluster randomised controlled trial in New Delhi, India
Authors: Parikh Rachana , Hoogendoorn Adriaan , Michelson Daniel , Ruwaard Jeroen , Sharma Rhea , Bhat Bhargav , Malik Kanika , Sahu Rooplata , Cuijpers Pim , Patel Vikram
Published: June 2021

Introduction

We evaluated a classroom-based sensitisation intervention that was designed to reduce demand-side barriers affecting referrals to a school counselling programme. The sensitisation intervention was offered in the context of a host trial evaluating a low-intensity problem-solving treatment for common adolescent mental health problems.

Methods

We conducted a stepped-wedge, cluster randomised controlled trial with 70 classes in 6 secondary schools serving low-income communities in New Delhi, India.The classes were randomised to receive a classroom sensitisation session involving a brief video presentation and moderated group discussion, delivered by a lay counsellor over one class period (intervention condition, IC), in two steps of 4 weeks each. The control condition (CC) was whole-school sensitisation (teacher-meetings and whole-school activities such as poster displays). The primary outcome was the proportion of students referred into the host trial. Secondary outcomes were the proportion of students who met mental health caseness criteria and the proportion of self-referred adolescents.

Results

Between 20 August 2018 and 9 December 2018, 835 students (23.3% of all students) were referred into the host trial. The referred sample included 591 boys (70.8%), and had a mean age of 15.8 years, SD=0.06; 194 students (31.8% of 610 with complete data) met mental health caseness criteria. The proportion of students referred in each trial conditionwas significantly higher in the IC (IC=21.7%, CC=1.5%, OR=111.36, 95% CI 35.56 to 348.77, p<0.001). The proportion of self-referred participants was also higher in the IC (IC=98.1%, CC=89.1%, Pearson χ2(1)=16.92, p<0.001). Although the proportion of referred students meeting caseness criteria was similar in both conditions (IC=32.0% vs CC=28.1%), the proportion weighted for the total student population was substantially higher in the IC (IC=5.2%, CC=0.3%, OR=52.39, 95% CI 12.49 to 219.66,p<0.001).

Conclusion

A single, lay counsellor-delivered, classroom sensitisation session increased psychological help-seeking for common mental health problems among secondary school pupils from urban, low-income communities in India.

Trial registration number

NCT03633916.
Active commuting and the risk of obesity, hypertension and diabetes: a systematic review and meta-analysis of observational studies
Authors: Wu Jian , Li Quanman , Feng Yu , Bhuyan Soumitra S , Tarimo Clifford Silver , Zeng Xin , Wu Cuiping , Chen Ning , Miao Yudong
Published: June 2021

Active commuting may hold a potential for preventing adverse health outcomes. However, evidence of the association of active commuting and the risk of health outcomes remains debatable. The current study systematically and quantitatively summarised research findings on the association between active commuting and the risk of the mentioned health outcomes. We comprehensively searched four databases (PubMed, EMBASE, Web of Science and Open Grey) from inception to 2 August 2020 for observational studies investigating the associations among adult population. Summary relative risks (RRs) and 95% CIs were estimated for the association. Heterogeneity was investigated using Cochran’s Q test and the I2 statistic. Restricted cubic splines were used to evaluate linear and nonlinear relations. The search yielded 7581 initial references. We included 28 articles in the meta-analysis. Compared with inactive commuting, active commuting reduced the risk of obesity (RR=0.88, 95% CI 0.83 to 0.94, I2=69.1%), hypertension (RR=0.95, 95% CI 0.87 to 1.04, I2=82.2%) and diabetes (RR=0.82, 95% CI 0.76 to 0.90, I2=44.5%). Restricted cubic splines showed linear associations between active commuting and obesity, hypertension and diabetes (Pnonlinearity=0.640; Pnonlinearity=0.886; Pnonlinearity=0.099). As compared with the lowest active commuting group, the risk of obesity, hypertension and diabetes in the highest active commuting group were reduced by 13% (95% CI 0.82 to 0.93, I2=65.2%); 6% (95% CI 0.86 to 1.02, I2=75.2%) and 19% (95% CI 0.73 to 0.91, I2=49.8%) respectively. Active commuting seemed to be associated with lower risk of obesity, hypertension and diabetes. However, the results should be interpreted cautiously because this meta-analysis was based solely on observational studies.

PROSPERO registration number

CRD42020202723.
Qualitative evaluation of primary care providers’ experiences caring for frequent users of the emergency department
Authors: Brunner Laureline , Canepa Allen Marina , Malebranche Mary , Hudon Catherine , Senn Nicolas , Hugli Olivier , Vu Francis , Akré Christina , Bodenmann Patrick
Published: June 2021

Objectives

Many interventions have been developed over the years to offer frequent users of the emergency department (FUEDs) better access to quality coordinated healthcare. Despite recognising the role primary care physicians (PCPs) play in FUEDs’ care, to date their perceptions of case management, the most studied intervention, have rarely been assessed. Furthermore, a gap regarding PCPs’ experience of caring for FUEDs persists. Thus, this study aimed to explore PCPs’ perceptions of the care provided to FUEDs in emergency and primary care settings, their views on the local case management team (CMT), and their suggestions to improve FUEDs’ care.

Design

Qualitative study using in-depth semistructured interviews and inductive thematic analysis.

Setting

Canton of Vaud, Switzerland.

Participants

Thirty PCPs participated, 16 in private practice (PP-PCPs) and 14 based at the Lausanne University Centre of General Medicine and Public Health (Unisanté—U-PCPs).

Results

U-PCPs and PP-PCPs thought that most FUEDs’ emergency department (ED) visits were legitimate, but questioned ED adequacy to meet FUEDs’ needs. Yet, both PCP groups reported encountering many challenges in FUEDs’ care themselves. In this context, PP-PCPs seemed more satisfied of the care they provided to FUEDs than U-PCPs. Generally, U-PCPs seemed to find more value in the CMT to help them care for FUEDs than PP-PCPs. To enhance FUEDs’ care, U-PCPs and PP-PCPs suggested enhancing collaboration with other healthcare providers. U-PCPs also wished to increase their availability, and some PP-PCPs considered outpatient clinics, larger group practices or medical centres most appropriate to handle FUEDs’ needs.

Conclusions

This study highlights the many challenges PCPs face in caring for FUEDs, that a CM intervention has the potential to mitigate, and provides ways forward in improving FUEDs’ care, including reinforced communication with the CMT and ED physicians, and structural changes to their own way of delivering care to FUEDs.
Sub-horizon modes and growth index in a linear scalar cosmological perturbations
Authors: Capistrano Abraão J. S.
Published: June 2021

We test a four dimensional cosmological model embedded in a five dimensional bulk space by means of the dynamical Nash-Greene theorem. In a fluid approach, we apply a joint likelihood analysis to the data with the Markov Chain Monte Carlo (MCMC) method for cosmological parameter estimation. We use recent datasets as the “Gold 2018” growth-rate data, the Planck2018/$$\varLambda $$ΛCDM data on the cosmic microwave background (CMB) anisotropies, the Baryon acoustic oscillations (BAO) measurements, the Pantheon Supernovae type Ia and the data on the Hubble parameterH(z) with redshift ranging from$$0.01< z < 2.3$$0.01<z<2.3. Performing the Information Criterion (IC) analysis, we find that the present model is in very good agreement with observations with a close statistical equivalence withwCDM cosmologies at 1-$$\sigma $$σlevel with a slightly larger growth profiles. By modifications of () code, we make a comparison between the models on their unlensed CMB TT temperature spectra. Moreover, the proposed model presents a low power spectrum by the reduction of the ISW effect at lower multipoles. We also find that the overall percentage relative difference of the growth index$$\varDelta \gamma (\%)$$Δγ(%)is up to 1.4$$\%$$%as compared towCDM pattern in sub-horizon scales.
Fractional linear maps in general relativity and quantum mechanics
Authors: Bellino Vito Flavio , Esposito Giampiero
Published: June 2021

This paper studies the nature of fractional linear transformations in a general relativity context as well as in a quantum theoretical framework. Two features are found to deserve special attention: the first is the possibility of separating the limit-point condition at infinity into loxodromic, hyperbolic, parabolic and elliptic cases. This is useful in a context in which one wants to look for a correspondence between essentially self-adjoint spherically symmetric Hamiltonians of quantum physics and the theory of Bondi–Metzner–Sachs transformations in general relativity. The analogy therefore arising suggests that further investigations might be performed for a theory in which the role of fractional linear maps is viewed as a bridge between the quantum theory and general relativity. The second aspect to point out is the possibility of interpreting the limit-point condition at both ends of the positive real line, for a second-order singular differential operator, which occurs frequently in applied quantum mechanics, as the limiting procedure arising from a very particular Kleinian group which is the hyperbolic cyclic group. In this framework, this work finds that a consistent system of equations can be derived and studied. Hence, one is led to consider the entire transcendental functions, from which it is possible to construct a fundamental system of solutions of a second-order differential equation with singular behavior at both ends of the positive real line, which in turn satisfy the limit-point conditions. Further developments in this direction might also be obtained by constructing a fundamental system of solutions and then deriving the differential equation whose solutions are the independent system first obtained. This guarantees two important properties at the same time: the essential self-adjointness of a second-order differential operator and the existence of a conserved quantity which is an automorphic function for the cyclic group chosen.
Martensite decomposition during post-heat treatments and the aging response of near-α Ti–6Al–2Sn–4Zr–2Mo (Ti-6242) titanium alloy processed by selective laser melting (SLM)
Authors: Fan Haiyang , Liu Yahui , Yang Shoufeng
Published: June 2021

Ti–6Al–2Sn–4Zr–2Mo (Ti-6242), a near-[Formula: see text] titanium alloy explicitly designed for high-temperature applications, consists of a martensitic structure after selective laser melting (SLM). However, martensite is thermally unstable and thus adverse to the long-term service at high temperatures. Hence, understanding martensite decomposition is a high priority for seeking post-heat treatment for SLMed Ti-6242. Besides, compared to the room-temperature titanium alloys like Ti–6Al–4V, aging treatment is indispensable to high-temperature near-[Formula: see text] titanium alloys so that their microstructures and mechanical properties are pre-stabilized before working at elevated temperatures. Therefore, the aging response of the material is another concern of this study. To elaborate the two concerns, SLMed Ti-6242 was first isothermally annealed at 650[Formula: see text]C and then water-quenched to room temperature, followed by standard aging at 595[Formula: see text]C. The microstructure analysis revealed a temperature-dependent martensite decomposition, which proceeded sluggishly at [Formula: see text]C despite a long duration but rapidly transformed into lamellar [Formula: see text] above the martensite transition zone (770[Formula: see text]C). As heating to [Formula: see text]C), it produced a coarse microstructure containing new martensites formed in water quenching. The subsequent mechanical testing indicated that SLM-built Ti-6242 is excellent in terms of both room- and high-temperature tensile properties, with around 1400 MPa (UTS)[Formula: see text]5% elongation and 1150 MPa (UTS)[Formula: see text]10% elongation, respectively. However, the combination of water quenching and aging embrittled the as-built material severely.
From the President: The Return to “Normal” Must Be a Call to Action
Authors: Wachsman Eric D.
Published: June 2021

2020 is a year that will live in infamy. The global pandemic has disrupted the lives and livelihood of almost everyone on the planet, and worse yet, killed millions. Thanks to science, death rates have dropped, and vaccines have been found that will slow and hopefully end the spread of this horrible disease. Life will return to “normal;” but what will that new “normal” be? I look forward to finally seeing my colleagues in person, in Orlando, at the 240th ECS Meeting this fall, but assume that in this new “normal” there will be a virtual component and some level of “distancing.”
High-Temperature Compatibility of Structural Alloys with Supercritical and Subcritical CO2
Authors: Pint Bruce A.
Published: June 2021

In searching for new working fluids for power generation, supercritical CO2 (sCO2) offers some attractive features for efficient cycles. However, compatibility with structural alloys is a concern. NiCr-based alloys have excellent compatibility at 600°-800°C at 20-30 MPa sCO2. However, conventional steels have restrictions in temperature because of carburization and accelerated oxidation in sCO2, similar to observations in CO2. To assess the impact of carburization on steel mechanical properties, small (25mm long) dogbone tensile bars are being exposed and tested after exposure at 450°-650°C. Only highly alloyed advanced austenitic steels are resistant to carburization at 650°-750°C, suggesting that Crrich oxide scales are good barriers to C ingress. Above 800°C, it is only possible to conduct subcritical evaluations at this time, but initial results suggest most conventional high-temperature Fe- and Ni-based alloys are more rapidly degraded by CO2 at higher temperatures. Coatings are a potential solution that require more study.
Perseverance Rover Lands on Mars
Authors: Taylor E. Jennings , Jackson Gregory S.
Published: June 2021

On February 18, 2021, at 3:55 p.m. EST, NASA’s Perseverance rover landed at the Jezero Crater on Mars. Perseverance is NASA’s most advanced rover to date and traveled 293 million miles (472 million kilometers) over 203 days; an average speed of over 60,000 miles per hour! After several weeks of testing, Perseverance will begin a two-year exploration of Mars’ Jezero Crater.