bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Test and Evaluation Space using Model Based Conceptual Design (MBCD) Techniques
Authors: Flanigan David , Robinson Kevin
Published: September 2019

During the initial concept development phase, systems engineers focus on defining the problem space and system functions in order to explore candidate concepts that may address the systems engineers' problems. Model Based Conceptual Design (MBCD) techniques may be used to assist the customer and other stakeholders develop a greater understanding of the system concept, as well as identifying areas in the system that are affected by changes in requirements. This approach has generally been documented for describing the system concept in the early stages in the lifecycle, without significant focus on the Test and Evaluation (T&E) space that would be needed to evaluate these concepts, or identifying where the T&E space would be affected with a change in requirements. Our hypothesis is that decision makers would equally gain insight into the T&E considerations as well as system space considerations using MBCD techniques. An approach is offered to extend the previously published MBCD methodology to better consider the T&E space.
The Need for an Information‐based Approach for Requirement Development and Management
Authors: Wheatcraft Lou , Ryan Mike , Llorens Juan , Dick Jeremy
Published: September 2019

In many organizations, the quality of the individual requirement statements and sets of requirements is often poor, not having the characteristics of well‐formed requirement statements and sets of requirements. Correctness, completeness, consistency, ambiguity, feasibility, implementation, leveling, etc. are common issues. This puts a heavy burden on the design team to address and correct these issues. Given these issues, it is common for modern systems engineers to even question the need for text‐based requirements. This paper discusses why text‐based requirements are still important, their role in the overall systems engineering lifecycle activities, and identifies key issues in the current approach many organizations practice concerning requirement development and management (RDM) – especially how RDM relates to current model‐based design and systems engineering approaches.
Fumonisin B1 damages the barrier functions of porcine intestinal epithelial cells in vitro
Authors: Chen Zhigang , Chen Huiyu , Li Xue , Yuan Qiaoling , Su Jianming , Yang Lei , Ning Lingzhong , Lei Hongyu
Published: September 2019

Fumonisins (Fums) are mycotoxins widely distributed in crops and feed, and ingestion of Fums‐contaminated crops is harmful to animal health. The purpose of this study is to explore the effect of Fum B1 (FB1) on barrier functions of porcine intestinal epithelial cells, IPEC‐J2, to clarify the intestinal toxicity of Fums in pigs. The results showed that the persistent treatment of FB1 significantly decreased the viability of IPEC‐J2. Moreover, the expressions of Claudin 1, Occludin, Zonula Occluden‐1 (ZO‐1) on the messenger RNA (mRNA), and protein levels and MUC1 on the mRNA level were significantly inhibited after FB1 treatment, while the mRNA relative expression level of MUC2 was clearly increased. FB1 also enhanced the monolayer cell permeability of IPEC‐J2. Importantly, FB1 promoted the expression of phosphorylated extracellular regulated protein kinase (p‐ERK1/2). These data suggest that long‐term treatment of FB1 can suppress IPEC‐J2 proliferation, damage tight junctions of IPEC‐J2, and regulate expression of mucins to induce the damage of barrier functions of porcine intestinal epithelial cells, which may be associated with the ERK1/2 phosphorylation pathway.
Polyinosinic‐polycytidylic acid accelerates intestinal stem cell proliferation via modulating Myc expression
Authors: Zeng Huihong , Tang Jiahui , Yue Mengzhen , Cheng Jiaoqi , Fan Ying , Li Manjun , Zhang Xinxin , Li Huan , Duan Hongyi , Zhang Minqing , Fan Guangqin , Zhu Qingxian , Shao Lijian
Published: September 2019

It is well known that exposure of double‐stranded RNA (dsRNA) to intestine immediately induces villus damage with severe diarrhea, which is mediated by toll‐like receptor 3 signaling activation. However, the role of intestinal stem cells (ISCs) remains obscure during the pathology. In the present study, polyinosinic‐polycytidylic acid (poly[I:C]), mimicking viral dsRNA, was used to establish intestinal damage model. Mice were acutely and chronically exposed to poly(I:C), and ISCs in jejunum were analyzed. The results showed that the height of villus was shorter 48 hr after acute poly(I:C) exposure compared with that of controls, while chronic poly(I:C) treatment increased both villus height and crypt depth in jejunum compared with control animals. The numbers of ISCs in jejunum were significantly increased after acute and chronic poly(I:C) exposure. Poly (I:C)‐stimulated ISCs have stronger capacities to differentiate into intestine endocrine cells. Mechanistically, poly(I:C) treatment increased expression of Stat1 and Axin2 in the intestinal crypt, which was along with increased expression of Myc, Bcl2, and ISC proliferation. These findings suggest that dsRNA exposure could induce ISC proliferation to ameliorate dsRNA‐induced intestinal injury.
Differential expression of inflammasome regulatory transcripts in periodontal disease
Authors: Aral Kübra , Berdeli Eynar , Cooper Paul Roy , Milward Michael Robert , Kapila Yvonne , Karadede Ünal Beyza , Aral Cüneyt Asım , Berdeli Afig
Published: September 2019

Background

The inflammasome modulates the release of key proinflammatory cytokines associated with periodontal disease pathogenesis. The aim of this study was to evaluate the expression of proteins that regulate the inflammasome, namely pyrin domain‐only proteins (POPs), caspase activation recruitment domain (CARD)‐only proteins, and tripartite motif‐containing (TRIM) proteins, in periodontal diseases.

Methods

A total of 68 participants (34 males and 34 females) were divided into four groups, including periodontal health (H), gingivitis (G), chronic periodontitis (CP), and aggressive periodontitis (AgP) based on clinical parameters. Gingival tissue samples were obtained from all participants for reverse transcription polymerase chain reaction (RT‐PCR)‐based gene expression analyses of molecules that regulate the inflammasome, including apoptosis‐associated speck‐like protein (ASC) containing CARD, caspase‐1, interleukin‐1β (IL‐1β), interleukin‐18 (IL‐18), nucleotide‐binding domain, leucine rich family (NLR) pyrin domain containing 3 (NLRP3), NLR family pyrin domain containing 2 (NLRP2), AIM2 (absent in melanoma 2), POP1, POP2, CARD16, CARD18, TRIM16, and TRIM20 by RT‐PCR.

Results

NLRP3 and IL‐1β were upregulated in the G, CP, and AgP groups compared with group H (P < 0.05). AIM2 was downregulated in the CP group compared with the H, G, and AgP groups (P < 0.05). TRIM20, TRIM16, and CARD18 were downregulated in the G, CP, and AgP groups compared with the H group (P < 0.05). POP1 and POP2 were downregulated in the CP and AgP, and AgP and G groups, respectively (P < 0.05).

Conclusion

Active periodontal disease may result in downregulation of inflammasome regulators that may increase the activity of NLRP3 and IL‐1β in periodontal disease.
Enhanced Temperature Stability of High Energy Density Ferroelectric Polymer Blends: The Spatial Confinement Effect
Authors: Liu Yongbin , Gao Jinghui , Wang Yan , Zhou Jun , Cao Liang , He Zhixin , Zhang Yang , Tang Chao , Zhong Lisheng
Published: September 2019

Thermal stability of polymer structure is a key to achieve stable energy density at elevated temperature for ferroelectric‐polymer‐based capacitors. Here, a poly (vinylidene fluoride) / polymethyl methacrylate (PMMA) blend with a stabilized spherulite structure displaying steady energy density around 7.8–9.8 J cm−3 across the temperature range up to 70 °C is reported, which outperforms most neat ferroelectric polymers at elevated temperature. The microstructure of the blend observed by atomic force microscopy exhibits an alternating lamellar structure (crystalline/mixed amorphous layers) within spherulites, which might be rationalized by PMMA being gradually expelled from the spherulite and finally staying between PVDF lamellae during crystallization. The structure with rigid amorphous layers can induce a spatial confinement effect of chain motion and structural change under thermal stress, which is evidenced by temperature‐insensitive long period in small‐angle X‐ray scattering measurements. The enhanced thermal stability of energy storage can be attributed to the constraint on free volume and carrier transportation caused by the spatial confinement. Our findings provide a strategy to attain temperature‐stable high‐energy‐density ferroelectric polymers for energy storage capacitors.
The Display Firmament Shifts
Authors: Werner Ken
Published: September 2019

Display companies broke new ground at this year's Display Week, where they showcased a host of innovative new technologies, products, and approaches.
Sensitivity analysis on responsive pricing and production under imperfect demand updating
Authors: Chua Geoffrey A. , Liu Yan
Published: September 2019

This paper examines three types of sensitivity analysis on a firm's responsive pricing and responsive production strategies under imperfect demand updating. Demand has a multiplicative form where the market size updates according to a bivariate normal model. First, we show that both responsive production and responsive pricing resemble the classical pricing newsvendor with posterior demand uncertainty in terms of the optimal performance and first‐stage decision. Second, we show that the performance of responsive production is sensitive to the first‐stage decision, but responsive pricing is insensitive. This suggests that a “posterior rationale” (ie, using the optimal production decision from the classical pricing newsvendor with expected posterior uncertainty) allows a simple and near‐optimal first‐stage production heuristic for responsive pricing. However, responsive production obtains higher expected profits than responsive pricing under certain conditions. This implies that the firm's ability to calculate the first‐stage decision correctly can help determine which responsive strategy to use. Lastly, we find that the firm's performance is not sensitive to the parameter uncertainty coming from the market size, total uncertainty level and information quality, but is sensitive to uncertainty originating from the procurement cost and price‐elasticity.
Experiences of mothers with preterm babies at a Mother and Baby Unit of a tertiary hospital: A descriptive phenomenological study
Authors: Lomotey Alberta Yemotsoo , Bam Victoria , Diji Abigail Kusi‐Amponsah , Asante Ernest , Asante Hannah Boatemaa , Osei Joyce
Published: September 2019

Aim

To describe the lived experiences of mothers with preterm babies at a Mother and Baby Unit (MBU) of a tertiary hospital.

Design

A descriptive phenomenological approach.

Method

Ten mothers were purposively sampled during the month of May, 2017 to describe their experiences of having preterm babies. Recorded in‐depth individual interviews were transcribed verbatim; codes were generated and inductively organised into themes.

Results

Four themes were actively generated: ‘Emotional experiences of mothers’, ‘Mother‐baby interaction’, ‘Perception on care and support’ and ‘Challenges within Mother and Baby Unit environment’. Mothers were anxious about the premature delivery and were afraid of possible infant's death. They cherished interactions with their babies during kangaroo mother care and breastfeeding. Mothers applauded the nurses for their professional competence. They expressed concerns about inadequate accommodation, high cost of care, the frequency and duration of mother–baby interactions.
Elements in scenario‐based simulation associated with nursing students' self‐confidence and satisfaction: A cross‐sectional study
Authors: Olaussen Camilla , Heggdal Kristin , Tvedt Christine Raaen
Published: September 2019

Aim

To identify elements in scenario‐based simulation associated with nursing students' satisfaction with the simulation activity and self‐confidence in managing the simulated patient situation. The study will provide insight to improve the use of simulation as a learning strategy.

Design

A cross‐sectional study.

Method

The Student Satisfaction and Self‐Confidence in Learning scale was used as the outcome measure to identify associations with elements of the Simulation Design Scale and the Educational Practices Questionnaire scale after scenario‐based simulation using patient simulators. First‐year nursing students at a university college in Norway (N = 202) were invited to participate and (N = 187) responded to the questionnaires.

Results

The mean scores for self‐confidence and satisfaction were 4.16 and 4.57, respectively. In the final multiple linear regression analysis, active learning was associated with satisfaction with the simulation activity, while clear objectives and active learning were associated with self‐confidence in managing the simulated patient situation.
General and Scalable Fabrication of Core–Shell Metal Sulfides@C Anchored on 3D N‐Doped Foam toward Flexible Sodium Ion Batteries
Authors: Ma Xiangdong , Xiong Xunhui , Zou Pinjuan , Liu Weizhen , Wang Fei , Liang Longwei , Liu Yong , Yuan Changzhou , Lin Zhang
Published: September 2019

Flexible self‐standing transitional metal sulfides (TMSs)/carbon nanoarchitectures have attracted widespread research interests for sodium ion batteries (SIBs), thanks to their enormous capability to address intrinsic issues of TMSs for SIBs applications. However, controllable synthesis of hierarchical hybrid structures is always laborious and involves complicated procedures. Herein, a simple yet general and scalable adsorption‐annealing strategy is first devised to finely construct core–shell carbon‐coated TMSs (TMSs@C, including Co9S8@C, FeS@C, Ni3S2@C, MnS@C, and ZnS@C) nanoparticles anchored on 3D N‐doped carbon foam (3DNCF) via the coordination and hydrogen‐bond adsorption. Benefiting from synergistic contributions from strong chemical affinity between nanodimensional TMSs and 3DNCF, efficient electronic/ionic transport channels, as well as a uniform carbon accommodating layer, the resulted self‐standing TMSs@C/3DNCF electrodes exhibit distinguished sodium storage performances, including large reversible capacities, high rate behaviors, and exceptional long‐span cycle stability in both half cells and flexible full devices. More significantly, the smart methodology developed holds huge promise for commercialization of binder‐free TMSs@C/3DNCF anodes toward advanced flexible SIBs.
Hofmeister Effect‐Aided Assembly of Enhanced Hydrogel Supercapacitor with Excellent Interfacial Contact and Reliability
Authors: Wei Junjie , Wang Qigang
Published: September 2019

The hydrogel electrolyte has been researched extensively to meet the multifunctional demands for energy storage devices. However, due to the weak mechanical strength of hydrogel electrolytes, the poor interfacial contact between electrolyte and electrode, and the conflict between mechanical strength and interface, the reliability and interfacial needed are needed to be further improved. Herein, an extremely tough poly(vinyl alcohol) (PVA) hydrogel electrolyte and a novel “two‐step” in situ assembly method for supercapacitors are developed utilizing the Hofmeister effect on PVA molecules. The supercapacitor assembled by this method exhibits excellent performance, especially in reliability and interfacial properties, attributed to the ultrahigh mechanical properties and the unique interface binding phase. The investigation offers a simple and versatile way to construct next generation multifunctional solid‐state energy storage devices with superior safety, stability, and environmental adaptability.
Trace amounts of African swine fever virus DNA detected in insects collected from an infected pig farm in Estonia
Authors: Herm Reet , Tummeleht Lea , Jürison Margret , Vilem Annika , Viltrop Arvo
Published: September 2019

Background

African swine fever (ASF), a severe multi‐systemic disease in pigs, was introduced into Estonia in 2014. The majority of outbreaks have occurred during the summer months. Given that ASFV is transmitted in a sylvatic cycle that includes the transmission by African soft ticks and that mechanical transmission by flying insects was shown, transmission by other arthropod vectors need to be considered.

Objectives

Here, we report the results of a pilot study on flying insects caught on an outbreak farm during epidemiological investigations.

Methods

In brief, 15 different insect species (flies and mosquitoes) were collected by random catch using an aerial net. Nucleic acids derived from these samples or their pools were tested for African swine fever virus (ASFV) DNA by real‐time PCR.

Results and Conclusions

Viral DNA was detected in small quantities in two samples from flies and mosquitoes. Given the slow spread of virus within the farm, the impact of these findings seems rather low, but a role in local transmission cannot be ruled out. However, given the very low number of insects sampled, and taken into the account that viral isolation was not performed and insects outside the farm were not investigated, future investigations are needed to assess the true impact of insects as mechanical vectors.
Market power in bilateral oligopoly markets with non-expandable infrastructures
Authors: Funaki Yukihiko , Houba Harold , Motchenkova Evgenia
Published: September 2019

We develop a novel model of price-fee competition in bilateral oligopoly markets with non-expandable infrastructures and costly transportation. The model captures a variety of real market situations and it is the continuous quantity version of the assignment game with indivisible goods on a fixed network. We define and characterize stable market outcomes. Buyers exclusively trade with the supplier with whom they achieve maximal bilateral joint welfare at prices equal to marginal costs. Maximal fees and the suppliers’ market power are restricted by the buyers’ credible threats to switch suppliers. Maximal fees also arise from a negotiation model that extends price competition to price-fee competition. Competition in both prices and fees necessarily emerges. It improves welfare compared to price competition, but buyers will not be better off. The minimal infrastructure achieving maximal aggregate welfare differs from the minimal network that protects buyers most.
Myocardial bridging is an independent predictor of positive spasm provocation testing by intracoronary ergonovine injections: a retrospective observational study
Authors: Arai Riku , Kano Hiroto , Suzuki Shinya , Semba Hiroaki , Arita Takuto , Yagi Naoharu , Otsuka Takayuki , Matsuno Shunsuke , Matsuhama Minoru , Kato Yuko , Uejima Tokuhisa , Oikawa Yuji , Okumura Yasuo , Yajima Junji , Yamashita Takeshi
Published: September 2019

The relationship between myocardial bridging (MB) and coronary spasms during spasm provocation testing (SPT) remains unclear. We aimed to investigate whether MB was correlated with the SPT by ergonovine (ER) injections in a retrospective observational study. Of the 3340 patients who underwent a first coronary angiography, 166 underwent SPT using ER injections and were divided into 2 groups: MB(+) (n = 23), and MB(−) (n = 143). MB was defined as an angiographic reduction in the diameter of the coronary artery during systole. The patients who had severe organic stenosis in the left anterior descending coronary artery were excluded. The MB(+) group more frequently had diabetes mellitus and chronic kidney disease, and a thicker interventricular septum thickness. The rate of SPT-positivity was higher in the MB(+) group than MB(−) group (56.5% vs. 22.4%, P = 0.001). A multivariate regression analysis showed that the presence of MB was independently associated with SPT-positivity (odds ratio 5.587, 95% confidence interval 2.061–15.149, P = 0.001). In conclusion, coronary spasms during provocation tests with ER independently correlated with the MB. MB may predict coronary spasms.
The value of a liability cash flow in discrete time subject to capital requirements
Authors: Engsner Hampus , Lindensjö Kristoffer , Lindskog Filip
Published: September 2019

The aim of this paper is to define the market-consistent multi-period value of an insurance liability cash flow in discrete time subject to repeated capital requirements, and explore its properties. In line with current regulatory frameworks, the presented approach is based on a hypothetical transfer of the original liability and a replicating portfolio to an empty corporate entity, whose owner must comply with repeated one-period capital requirements but has the option to terminate the ownership at any time. The value of the liability is defined as the no-arbitrage price of the cash flow to the policyholders, optimally stopped from the owner’s perspective, taking capital requirements into account. The value is computed as the solution to a sequence of coupled optimal stopping problems or, equivalently, as the solution to a backward recursion.
Pharmacokinetic and pharmacodynamic analysis of fulvestrant in preclinical models of breast cancer to assess the importance of its estrogen receptor-α degrader activity in antitumor efficacy
Authors: Wardell Suzanne E. , Yllanes Alexander P. , Chao Christina A. , Bae Yeeun , Andreano Kaitlyn J. , Desautels Taylor K. , Heetderks Kendall A. , Blitzer Jeremy T. , Norris John D. , McDonnell Donald P.
Published: September 2019

Purpose

Fulvestrant is a selective estrogen receptor downregulator (SERD) that is approved for first- or second-line use as a single agent or in combination with cyclin dependent kinase or phosphatidylinositol 3-kinase inhibitors for the treatment of metastatic breast cancer. Fulvestrant exhibits exceptionally effective antitumor activity in preclinical models of breast cancer, a success that has been attributed to its robust SERD activity despite modest receptor downregulation in patient tumors. By modeling human exposures in animal models we probe the absolute need for SERD activity.

Methods

Three xenograft models of endocrine therapy-resistant breast cancer were used to evaluate the efficacy of fulvestrant administered in doses historically used in preclinical studies in the field or by using a dose regimen intended to model clinical exposure levels. Pharmacokinetic and pharmacodynamic analyses were conducted to evaluate plasma exposure and intratumoral ER downregulation.

Results

A clinically relevant 25 mg/kg dose of fulvestrant exhibited antitumor efficacy comparable to the historically used 200 mg/kg dose, but at this lower dose it did not result in robust ER downregulation. Further, the antitumor efficacy of the lower dose of fulvestrant was comparable to that observed for other oral SERDs currently in development.

Conclusion

The use of clinically unachievable exposure levels of fulvestrant as a benchmark in preclinical development of SERDs may negatively impact the selection of those molecules that are advanced for clinical development. Further, these studies suggest that antagonist efficacy, as opposed to SERD activity, is likely to be the primary driver of clinical response.
Long-term outcome of spiral ileal neobladder with orthotopic ureteral reimplantation
Authors: Zhong Huan , Shen Yuefan , Yao Zixiang , Chen Xiaonong , Gao Jianguo , Xiang Anping , Wang Weigao
Published: September 2019

Purpose

The purpose of this study was to analyze long-term complications, urodynamics, and quality of life (QoL) of patients after orthotopic ileal neobladder with orthotopic ureteral reimplantation to enrich clinical data and provide a basis for clinical use of this surgery.

Methods

Between January 2007 and January 2013, 72 consecutive patients who underwent spiral ileal neobladder following radical cystectomy were enrolled. The neobladder was created using a modified Camey-II technique. Complications were reviewed and staged according to Clavien–Dindo classification and evaluated in long-term follow-up. Urodynamics were performed, and QoL was assessed by the Functional Assessment of Cancer Therapy for Bladder Cancer (FACT-BL) instrument.

Results

The total follow-up time was 60 months, and the total survival rates at 3 and 5 years after surgery were 76.4% (55/72) and 65.3% (47/72), respectively. There were 34 (47.2%) early complications in 23 (31.9%) patients and 42 (58.3%) late complications in 35 (48.6%) patients. The total satisfactory control rates were 69.1% and 66.0% at 3 and 5 years after the surgery, respectively. Urodynamic studies were performed in some patients, and the receiver operating characteristic curve analysis showed that pressure at maximum capacity, compliance, and post void residual urine had predictive value for mortality (P < 0.05). The total FACT-BL scores of patients at 1, 3, and 5 years postoperation were 125.0 ± 15.2, 127.0 ± 16.2, and 120.6 ± 13.5, respectively, and it decreased at 5 years postoperation (P < 0.05).

Conclusion

Spiral ileal neobladder with orthotopic ureteral reimplantation offers satisfactory long-term results, and urodynamic monitoring might have prognostic value.
On Identification and Non-normal Simulation in Ordinal Covariance and Item Response Models
Authors: Foldnes Njål , Grønneberg Steffen
Published: September 2019

A standard approach for handling ordinal data in covariance analysis such as structural equation modeling is to assume that the data were produced by discretizing a multivariate normal vector. Recently, concern has been raised that this approach may be less robust to violation of the normality assumption than previously reported. We propose a new perspective for studying the robustness toward distributional misspecification in ordinal models using a class of non-normal ordinal covariance models. We show how to simulate data from such models, and our simulation results indicate that standard methodology is sensitive to violation of normality. This emphasizes the importance of testing distributional assumptions in empirical studies. We include simulation results on the performance of such tests.
Semiotic work in the science classroom
Authors: Bezemer Jeff , Kress Gunther
Published: September 2019

This review is on Lilian Pozzer and Wolff-Michael Roth’s “A cultural-historical perspective on the multimodal development of concepts in science lectures.” We offer some brief observations from within the paradigm of social semiotics, more specifically from our own attempts to produce multimodal accounts of learning in and beyond the classroom. We propose to treat meaning as the outcome of social action and interaction: clearly, environments and practices of learning and teaching come within that frame. We comment on the categories and implicit distinctions of verbal vs nonverbal, and the relative visibility and invisibility of meaning makers (teacher and learner) and their use of semiotic resources in accounts of learning. We highlight the agency of learners and propose a transformation of the role of “teacher” into that of “designer (of learning environments)”. We conclude by briefly speculating on the possibility of bringing the two distinct paradigms into dialogue and conjunction.
Worshipping Local? Congregation Proximity, Attendance, and Neighborhood Commitment
Authors: Dougherty Kevin D. , Mulder Mark T.
Published: September 2019

The growth of suburban and exurban areas pushed many Americans into commuter lifestyles. People drive automobiles to work, to shop, to play, and presumably to worship. Yet, recent decades have birthed a countermovement that pulls people back to urban centers and an emphasis on local environments, i.e. to “go local.” Recognizing these centrifugal and centripetal forces, this study seeks to answer two interrelated questions: Are Americans traveling further to a place of worship than in the past? And, does the proximity of a person's place of worship impact religious participation and neighborhood commitment? We use data from the 2017 Baylor Religion Survey to test three hypotheses. Our findings indicate that Americans lived further from their place of worship in 2017 than they did in 2001 or 2009. The benefits of worshipping local are mixed. People who belong to a congregation in their neighborhood attend more frequently, but they do not report feeling closer to their neighbors or more satisfied with the neighborhood. Rather, attending religious service, regardless of location, is associated with higher neighborhood commitment.
Clear skies ahead: optimizing the learning environment for critical thinking from a qualitative analysis of interviews with expert teachers
Authors: Jaffe Lynn E. , Lindell Deborah , Sullivan Amy M. , Huang Grace C.
Published: September 2019

Introduction The learning environment refers to the physical, pedagogical, and psychosocial contexts in which learning occurs and critically influences the educational experience of trainees in the health professions. However, the manner in which individual faculty explicitly organize the educational setting to facilitate learning of essential competencies such as critical thinking deserves more examination; lack of attention to this component can undermine the formal curriculum. The purpose of our study was to examine how faculty shape the learning environment to advance their learners’ development of critical thinking.

Methods We took a constructivist grounded theory approach using the framework method for qualitative content analysis. Data were derived from interviews conducted with 44 faculty identified as skilled teachers of critical thinking at eight academic health professions institutions.

Results Three major themes emerged regarding participants’ descriptions of their experiences of how they optimized the learning environment to support critical thinking: 1) Setting the atmosphere (establishing ground rules, focusing on process rather than answers, and building trust), 2) Maintaining the climate (gently pushing learners, tolerating discomfort, and adjusting to learner level), and 3) Weathering the storm (responses to challenges to learning critical thinking, including time and effort, negative evaluations, and resistance to effortful learning).

Discussion An optimal learning environment for critical thinking was actively created by faculty to establish a safe environment and shared understanding of expectations. Understanding how to produce a conducive learning climate is paramount in
Plasma neurofilament light associates with Alzheimer's disease metabolic decline in amyloid‐positive individuals
Authors: Benedet Andréa L. , Ashton Nicholas J. , Pascoal Tharick A. , Leuzy Antoine , Mathotaarachchi Sulantha , Kang Min S. , Therriault Joseph , Savard Melissa , Chamoun Mira , Schöll Michael , Zimmer Eduardo R. , Gauthier Serge , Labbe Aurélie , Zetterberg Henrik , Blennow Kaj , Neto Pedro R. ,   Alzheimer's Disease Neuroimaging Initiative
Published: September 2019

Introduction

Neurofilament light chain (NfL) is a promising blood biomarker to detect neurodegeneration in Alzheimer's disease (AD) and other brain disorders. However, there are limited reports of how longitudinal NfL relates to imaging biomarkers. We herein investigated the relationship between blood NfL and brain metabolism in AD.

Methods

Voxelwise regression models tested the cross‐sectional association between [18F]fluorodeoxyglucose ([18F]FDG) and both plasma and cerebrospinal fluid NfL in cognitively impaired and unimpaired subjects. Linear mixed models were also used to test the longitudinal association between NfL and [18F]FDG in amyloid positive (Aβ+) and negative (Aβ−) subjects.

Results

Higher concentrations of plasma and cerebrospinal fluid NfL were associated with reduced [18F]FDG uptake in correspondent brain regions. In Aβ+ participants, NfL associates with hypometabolism in AD‐vulnerable regions. Longitudinal changes in the association [18F]FDG‐NfL were confined to cognitively impaired Aβ+ individuals.

Discussion

These findings indicate that plasma NfL is a proxy for neurodegeneration in AD‐related regions in Aβ+ subjects.
Forced synchronization of quasiperiodic oscillations in a thermoacoustic system
Authors: Guan Yu , Gupta Vikrant , Wan Minping , Li Larry K. B.
Published: September 2019

In self-excited combustion systems, the application of open-loop forcing is known to be an effective strategy for controlling periodic thermoacoustic oscillations, but it is not known whether and under what conditions such a strategy would work on thermoacoustic oscillations that are not simply periodic. In this study, we experimentally examine the effect of periodic acoustic forcing on a prototypical thermoacoustic system consisting of a ducted laminar premixed flame oscillating quasiperiodically on an ergodic $\mathbb{T}^{2}$ torus at two incommensurate natural frequencies, $f_{1}$ and $f_{2}$. Compared with that of a classical period-1 system, complete synchronization of this $\mathbb{T}_{1,2}^{2}$ system is found to occur via a more intricate route involving three sequential steps: as the forcing amplitude, $\unicode[STIX]{x1D716}_{f}$, increases at a fixed forcing frequency, $f_{f}$, the system transitions first (i) to ergodic $\mathbb{T}_{1,2,f}^{3}$ quasiperiodicity; then (ii) to resonant $\mathbb{T}_{1,f}^{2}$ quasiperiodicity as the weaker of the two natural modes, $f_{2}$, synchronizes first, leading to partial synchronization; and finally (iii) to a $P1_{f}$ limit cycle as the remaining natural mode, $f_{1}$, also synchronizes, leading to complete synchronization. The minimum $\unicode[STIX]{x1D716}_{f}$ required for partial and complete synchronization decreases as $f_{f}$ approaches either $f_{1}$ or $f_{2}$, resulting in two primary Arnold tongues. However, when forced at an amplitude above that required for complete synchronization, the system can transition out of $P1_{f}$ and into $\mathbb{T}_{1,2,f}^{3}$ or $\mathbb{T}_{2,f}^{2}$. The optimal control strategy is to apply off-resonance forcing at a frequency around the weaker natural mode ($f_{2}$) and at an amplitude just sufficient to cause $P1_{f}$, because this produces the largest reduction in thermoacoustic amplitude via asynchronous quenching. Analysis of the Rayleigh index shows that this reduction is physically caused by a disruption of the positive coupling between the unsteady heat release rate of the flame and the $f_{1}$ and $f_{2}$ acoustic modes. If the forcing is applied near the stronger natural mode ($f_{1}$), however, resonant amplification can occur. We then phenomenologically model this $\mathbb{T}_{1,2}^{2}$ thermoacoustic system as two reactively coupled van der Pol oscillators subjected to external sinusoidal forcing, and find that many of its synchronization features – such as the three-step route to $P1_{f}$, the double Arnold tongues, asynchronous quenching and resonant amplification – can be qualitatively reproduced. This shows that these features are not limited to our particular system, but are universal features of forced self-excited oscillators. This study extends the applicability of open-loop control from classical period-1 systems with just a single time scale to ergodic $\mathbb{T}^{2}$ quasiperiodic systems with two incommensurate time scales.
Richtmyer–Meshkov instability of an unperturbed interface subjected to a diffracted convergent shock
Authors: Zou Liyong , Al-Marouf Mahamad , Cheng Wan , Samtaney Ravi , Ding Juchun , Luo Xisheng
Published: September 2019

The Richtmyer–Meshkov (RM) instability is numerically investigated on an unperturbed interface subjected to a diffracted convergent shock created by diffracting an initially cylindrical shock over a rigid cylinder. Four gas interfaces are considered with Atwood number ranging from $-0.18$ to 0.67. Results indicate that the diffracted convergent shock increases its strength gradually and reduces its amplitude quickly when it propagates towards the convergence centre. After the strike of the diffracted convergent shock, the initially unperturbed interface deforms with a bulge structure at the centre and two interface steps at both sides, which can be ascribed to the non-uniformity of the pressure distribution behind the diffracted convergent shock. With the decrease of Atwood number, the bulge structure becomes more pronounced. Quantitatively, the interface amplitude experiences a fast but short growing stage and then enters a linear stage. A good collapse of the dimensionless amplitude is found for all cases, which indicates a weak dependence of the growth rate on Atwood number in the deformed shock-induced RM instability. Then the impulsive theory is modified by eliminating the Atwood number and considering the geometry convergence, which well predicts the amplitude growth for the deformed shock-induced RM instability. Finally, the underlying mechanism is decoupled into three parts, and it is found that both the impulsive pressure perturbation and the geometry convergence promote the growth of interface perturbation while the continuous pressure perturbation inhibits the growth. As the Atwood number decreases, the impulsive perturbation plays an increasingly important role, which suggests that the impulsive perturbation dominates the deformed shock-induced RM instability at the linear stage.
Deciphering Galileo: Communication and Secrecy before and after the Trial
Authors: Marcus Hannah , Findlen Paula
Published: September 2019

Galileo participated in exchanges of encrypted correspondence at key moments in his life. In 1610–11, following the publication of the “Sidereal Messenger,” ciphers helped Galileo to diplomatically reveal what he was observing through his telescope. After his Inquisition trial of 1633, Galileo and his closest allies relied on a substitution code (gergo) to protect the privacy of his conversations and to facilitate the removal of his library and manuscripts at Arcetri. Throughout this article, we position Galileo's use of codes within the rich contemporary literature about communicating securely and reflect on cryptic writing as a strategy of communication and dissimulation.
Agnes Arber, historian of botany and Darwinian sceptic
Authors: Feola Vittoria
Published: September 2019

This essay aims to reappraise Agnes Arber's contribution to the history of science with reference to her work in the history of botany and biology. Both her first and her last books (Herbals, 1912; The Mind and the Eye, 1954) are classics: the former in the history of botany, the latter in that of biology. As such, they are still cited today, albeit with increasing criticism. Her very last book was rejected by Cambridge University Press because it did not meet the publisher's academic standards – we shall return to it in due course. Despite Kathryn Packer's two essays about Arber's life in context, much remains to be done toward a just appreciation of her research. We need such a reappraisal in order to avoid anachronistic criticisms of her contributions to the historiography of botany, or, on the other hand, uncritical applause for her studies in plant morphology.
New conodont records of the Los Sombreros Formation (Cambrian–Ordovician) from the Western Precordillera, Argentina: biostratigraphic and palaeoenvironmental implications
Authors: Torre Gabriela , Albanesi Guillermo L.
Published: September 2019

The presence of a carbonate platform that interfingers towards the west with slope facies allows for the identification of an ancient lower Palaeozoic continental margin in the Western Precordillera of Argentina. The Los Sombreros Formation is essential for the interpretation of the continental slope of the Precordillera, which accreted to Gondwana as part of the Cuyania Terrane in the early Palaeozoic. The age of these slope deposits is controversial; therefore, a precise biostratigraphic scheme is critical to reveal the evolution of the South American continental margin of Gondwana. The study of lithic deposits of two sections of the Los Sombreros Formation, the El Salto and Los Túneles sections, provides important information for further understanding the depositional history of the slope. At El Salto section, the conodonts recovered from an allochthonous block refer to theCordylodus proavusZone (upper Furongian). The conodonts recovered from the matrix of a calclithite bed of the Los Sombreros Formation in the Los Túneles section are assigned to theLenodus variabilisZone (early Darriwilian), providing a minimum age for this stratigraphic unit. In addition, clasts from this sample yielded conodonts from thePaltodus deltifer−Macerodus dianaezones (upper Tremadocian). The contrasting conodont colour alterations and preservation states from the elements of two latter records, coming from the same sample, argue the reworked clasts originated in the carbonate platform and later transported to the slope during the accretion process of the Precordilleran Terrane to the South American Gondwanan margin during the Middle–Late Ordovician.
Modulation of feed composition is able to make hens less attractive to the poultry red mite Dermanyssus gallinae
Authors: El Adouzi Marine , Arriaga-Jiménez Alfonsina , Dormont Laurent , Barthes Nicolas , Labalette Agathe , Lapeyre Benoît , Bonato Olivier , Roy Lise
Published: September 2019

The poultry red mite (PRM) is an obligatory haematophagous pest that causes substantial economic losses in poultry worldwide. The PRM does not live on the host but in the bird's environment and must find its host remotely. Hence, manipulating chicken odours is of interest. Several crude plant-originating volatile organic compounds (VOCs) have already been shown as repellent to Dermanyssus gallinae. We aimed to test whether these VOCs can interfere with PRM host-seeking behaviour by their oral administration to the poultry. The objectives were to determine (1) if hen odours are modified by supplemented feed ingestion and (2) if such treatment makes hens less attractive to the PRM. Chemical characterization by gas chromatography–mass spectrometry of the hen odour was conducted before and after the hens ingested the supplemented feed. The chromatograms obtained show that hen odour was substantially modified after the hens consumed it. Among the molecules recurrently detected from the supplemented hens, 26% were nearly absent in the unsupplemented hens. Behavioural choice tests to compare the effect of the modified and unmodified-host odours on the PRM show that some of the plant-originating emitted VOCs and the modified whole-hen odours were repellent to the PRM.
Impact of the caregiver burden on the effectiveness of a home-based palliative care program: A mediation analysis
Authors: Pereira-Morales Angela J. , Valencia Luis Enrique , Rojas Luis
Published: September 2019

Objective

The growing aging population and the high prevalence of several concomitant chronic diseases have contributed to the elevated rates of caregiver burden and suffering in patients. In turn, intending to relieve unnecessary pain in patients, there has been a rapid growth of outpatient palliative care programs. However, little has been studied about caregiver burden as a relevant factor potentially affecting the effectiveness of these programs. This study aimed to determine the extent of caregiver burden as a possible mediator on the effectiveness of a home-based palliative care program.

Method

Sixty-six palliative patients (56% women; mean age + SD = 71, 6 ± 17.7) and their caregivers were assessed with measures for physical, emotional, and psychological symptoms before and 1 month after the start of a home-based palliative care program.

Results

The association between caregiver burden and palliative outcomes was corroborated with a categorical regression model (p < 0.01). Caregiver burden was found to be a significant mediator in the relationship between outcome measures for palliative care at baseline and after 1 month of enrollment in the program.

Significance of results

To our knowledge, this is the first study to assess the role of caregiver burden in the effectiveness of a home-based palliative care program. Although further work is required, the results indicate that a patient-focused intervention does not have the same beneficial effect if the caregiver burden is not addressed. Future home-based palliative care programs should focus on caregivers as well as patients, with particular attention to psychosocial intervention on caregivers.
TIME for Kids to Learn Gender Stereotypes: Analysis of Gender and Political Leadership in a Common Social Studies Resource for Children
Authors: Lay J. Celeste , Holman Mirya R. , Bos Angela L. , Greenlee Jill S. , Oxley Zoe M. , Buffett Allison
Published: September 2019

While early gendered messages mold children's expectations about the world, we know relatively little about the depictions of women in politics and exposure to gender stereotypes in elementary social studies curricula. In this article, we examine the coverage of political leaders in the children's magazine TIME for Kids, a source commonly found in elementary school classrooms. Coding all political content from this source over six years, we evaluate the presence of women political leaders and rate whether the leaders are described as possessing gender-stereotypic traits. Our results show that although TIME for Kids covers women leaders in greater proportion than their overall representation in politics, the content of the coverage contains gendered messages that portray politics as a stereotypically masculine field. We show that gendered traits are applied differently to men and to women in politics: feminine and communal traits are more likely to be applied to women leaders, while men and women are equally described as having masculine and agentic traits. Portrayals of women political leaders in stereotype-congruent ways is problematic because early messages influence children's views of gender roles.
Climate Refugees, Thinned Forests, and Other Things We’re Reading
Authors:   AGU
Published: September 2019

What Earth and space science stories are we recommending this week?
Soluble RAGE attenuates AngII-induced endothelial hyperpermeability by disrupting HMGB1-mediated crosstalk between AT1R and RAGE
Authors: Jeong Jisu , Lee Jiye , Lim Juyeon , Cho Soyoung , An Soyoung , Lee Myungeun , Yoon Nara , Seo Miran , Lim Soyeon , Park Sungha
Published: September 2019

Increased endothelial permeability, one of the earliest signs of endothelial dysfunction, is associated with the development of cardiovascular diseases such as hypertension and atherosclerosis. Recent studies suggest that the receptor for advanced glycation end products (RAGE) regulates endothelial permeability in inflammation. In the present study, we investigated the regulatory mechanism of RAGE in endothelial hyperpermeability induced by angiotensin II (Ang II), a well-known inflammatory mediator, and the potential therapeutic effect of soluble RAGE (sRAGE), a decoy receptor for RAGE ligands. For in vitro studies, Ang II-treated human umbilical vein endothelial cells (HUVECs) were treated with siRNA specific to either RAGE or sRAGE to disrupt RAGE-mediated signaling. Endothelial permeability was estimated using FITC-labeled dextran 40 and a resistance meter. To evaluate intercellular junction disruption, VE-cadherin expression was examined by western blotting and immunocytochemistry. Ang II increased the expression of the Ang II type 1 receptor (AT1R) and RAGE, and this increase was inhibited by sRAGE. sRAGE prevented Ang II-induced VE-cadherin disruption in HUVECs. For in vivo studies, Ang II-infused, atherosclerosis-prone apolipoprotein E knockout mice were utilized. Endothelial permeability was assessed by Evans blue staining of the aorta. Ang II increased endothelial barrier permeability, and this effect was significantly attenuated by sRAGE. Our data demonstrate that blockade of RAGE signaling using sRAGE attenuates Ang II-induced endothelial barrier permeability in vitro and in vivo and indicate the therapeutic potential of sRAGE in controlling vascular permeability under pathological conditions.