bluuebunny/crossref_metadata_2025 huggingface dataset:
PD-1 Inhibitor Plus Chemotherapy Versus Chemotherapy as First-line Treatment for Advanced Esophageal Cancer: A Systematic Review and Meta-Analysis
Authors: Lu Yao , Xu Mengli , Guan Lulu , Yang Yalan , Chen Yu , Yang Yuanyuan , Wang Feng
Published: April 2022

Immunotherapy combined with chemotherapy has recently changed the first-line treatment of several cancers. We performed a systematic review and meta-analysis to assess the efficacy and safety of programmed cell death 1 (PD-1) inhibitor plus chemotherapy as a first-line treatment for advanced esophageal cancer. Data were collected from eligible studies searched from PubMed, Web of Science, Cochrane Library, Embase, and meeting abstracts. The pooled hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) and the pooled odds ratios (ORs) for objective response rate and treatment-related adverse events (TRAEs) were estimated to assess the efficacy and safety of PD-1 inhibitor plus chemotherapy versus chemotherapy. We performed several subgroup analyses to explore the variables affecting immunotherapy efficacy in esophageal cancer. The 5-point Jadad scoring system, the bias risk assessment and sensitivity analyses were used to evaluate the quality of the meta-analysis. Compared with the chemotherapy group, the OS (HR=0.70; P<0.01) and PFS (HR=0.62; P<0.01) were significantly longer and the objective response rate (OR=2.07; P<0.01) was significantly higher in the PD-1 inhibitor plus chemotherapy group. An OS benefit was observed in patients regardless of histology or programmed cell death 1 ligand 1 combined positive score. OS and PFS were generally consistent across subgroups by clinical features. In safety analyses, PD-1 inhibitor plus chemotherapy had a significantly higher incidence of TRAEs (OR=1.85; P<0.01), but there was no significant difference in grade 3 or higher TRAEs (OR=1.24; P=0.05). Compared with chemotherapy, PD-1 inhibitor plus chemotherapy improves antitumor activity and controllable adverse events in the first-line treatment of advanced esophageal cancer.
Impact of Prenatal Exposure to Smoking on Child Health
Authors: MACIAG MICHELLE C. , YOUSUF AROUB , HAUPTMAN MARISSA
Published: April 2022

Prenatal exposure to tobacco smoke remains common, through active smoking and/or passive environmental exposure, and is linked to adverse childhood outcomes. Not only have high-quality studies and meta-analyses demonstrated increased risks of prenatal as well as postnatal complications, but adverse child outcomes are well described. In utero exposure to tobacco smoke has been associated with congenital anomalies, infant and teenager overweight and obesity, and neuropsychiatric sequelae. In addition, certain childhood malignancies have been linked to paternal smoking during pregnancy. In this chapter, adverse childhood outcomes related to intrauterine exposure to electronic cigarettes and marijuana are described.
Investigating the veracity of a sample of divergent published trial data in spinal pain
Authors: O'Connell Neil E. , Moore R. Andrew , Stewart Gavin , Fisher Emma , Hearn Leslie , Eccleston Christopher , Williams Amanda C de C
Published: April 2022

Evidence-based medicine is replete with studies assessing quality and bias, but few evaluating research integrity or trustworthiness. A recent Cochrane review of psychological interventions for chronic pain identified trials with a shared lead author with highly divergent results. We sought to systematically identify all similar trials from this author to explore their risk of bias, governance procedures, and trustworthiness. We searched OVID MEDLINE, EMBASE, CENTRAL, and PEDro from 2010 to December 22, 2021 for trials. We contacted the authors requesting details of trial registration, ethical approval, protocol, and access to the trial data for verification. We used the Cochrane risk-of-bias tool and the Cochrane Pregnancy and Childbirth group's Trustworthiness Screening Tool to guide systematic exploration of trustworthiness. Ten trials were included: 9 compared cognitive behavioural therapy and physical exercise to usual care, exercise alone, or physiotherapy and 1 compared 2 brief cognitive behavioural therapy programmes. Eight trials reported results divergent from the evidence base. Assessment of risk of bias and participant characteristics identified no substantial concerns. Responses from the lead author did not satisfactorily explain this divergence. Trustworthiness screening identified concerns about research governance, data plausibility at baseline, the results, and apparent data duplication. We discuss the findings within the context of methods for establishing the trustworthiness of research findings generally. Important concerns regarding the trustworthiness of these trials reduce our confidence in them. They should probably not be used to inform the results and conclusions of systematic reviews, in clinical training, policy documents, or any relevant instruction regarding adult chronic pain management.
Repeated Measures of Cognitive and Affective Learning Outcomes in Simulation Debriefing
Authors: Tawfik Andrew A. , Bradford Jacque , Gish-Lieberman Jaclyn , Gatewood Jessica
Published: April 2022

Introduction.

To better support the development of domain expertise, there has been considerable interest in the instructional strategies that afford opportunities for problem solving. Simulation-based learning includes case-based activities that support learners' transition into practice through experience and reflective debriefing.

Review of the Literature.

Simulation-based learning serves as a means for learners to practice psychomotor, affective, and cognitive skills. Although the literature suggests this is an effective strategy for supporting problem-solving skills, much of the literature is focused on measuring cognitive outcomes within a single case. As such, very few studies have simultaneously investigated (a) how debriefing in simulation-based education supports problem solving and (b) the degree to which cognitive and affective learning outcomes are variable throughout the problem-solving process.

Methodology.

To address this gap, this repeated-measures study examined the role of debriefing strategies in simulation-based learning experiences, which was designed to practice both cognitive and affective skills. In the control condition, participants were given 2 simulation-based laboratory instructional sessions and then assessed on cognitive (problem representation and solution generation) and affective learning (perceived self-efficacy) outcomes. In the comparison condition, participants engaged in debriefing sessions after each of the 2 simulation-based laboratory instructional sessions. For the cognitive outcomes, participants were assessed using the Think-Aloud Standardized Patient Examination instrument, which measured problem representation and solution generation. Acute care confidence survey was used to measure perceived self-efficacy.

Results.

The study found statistically significant gaps in early-stage measures of cognitive problem representation, but no difference was found in solution generation or perceived self-efficacy measures.

Conclusion.

This study reinforces the importance of debriefing in simulation-based education. Specifically, this study suggests that cognitive learning outcomes are variable during the problem-solving process, but affective learning outcomes are more fixed and may need more targeted debriefing.
Prospective validation of a transcriptomic severity classifier among patients with suspected acute infection and sepsis in the emergency department
Authors: Galtung Noa , Diehl-Wiesenecker Eva , Lehmann Dana , Markmann Natallia , Bergström Wilma H. , Wacker James , Liesenfeld Oliver , Mayhew Michael , Buturovic Ljubomir , Luethy Roland , Sweeney Timothy E. , Tauber Rudolf , Kappert Kai , Somasundaram Rajan , Bauer Wolfgang
Published: April 2022

Background and importance

mRNA-based host response signatures have been reported to improve sepsis diagnostics. Meanwhile, prognostic markers for the rapid and accurate prediction of severity in patients with suspected acute infections and sepsis remain an unmet need. IMX-SEV-2 is a 29-host-mRNA classifier designed to predict disease severity in patients with acute infection or sepsis.

Objective

Validation of the host-mRNA infection severity classifier IMX-SEV-2.

Design, settings and participants

Prospective, observational, convenience cohort of emergency department (ED) patients with suspected acute infections.

Outcome measures and analysis

Whole blood RNA tubes were analyzed using independently trained and validated composite target genes (IMX-SEV-2). IMX-SEV-2-generated risk scores for severity were compared to the patient outcomes in-hospital mortality and 72-h multiorgan failure.

Main results

Of the 312 eligible patients, 22 (7.1%) died in hospital and 58 (18.6%) experienced multiorgan failure within 72 h of presentation. For predicting in-hospital mortality, IMX-SEV-2 had a significantly higher area under the receiver operating characteristic(AUROC) of 0.84 [95% confidence intervals (CI), 0.76–0.93] compared to 0.76 (0.64–0.87) for lactate, 0.68 (0.57–0.79) for quick Sequential Organ Failure Assessment (qSOFA) and 0.75 (0.65–0.85) for National Early Warning Score 2 (NEWS2), (P = 0.015, 0.001 and 0.013, respectively). For identifying and predicting 72-h multiorgan failure, the AUROC of IMX-SEV-2 was 0.76 (0.68–0.83), not significantly different from lactate (0.73, 0.65–0.81), qSOFA (0.77, 0.70–0.83) or NEWS2 (0.81, 0.75–0.86).

Conclusion

The IMX-SEV-2 classifier showed a superior prediction of in-hospital mortality compared to biomarkers and clinical scores among ED patients with suspected infections. No improvement for predicting multiorgan failure was found compared to established scores or biomarkers. Identifying patients with a high risk of mortality or multiorgan failure may improve patient outcomes, resource utilization and guide therapy decision-making.
Data Needs and Availability for Specialty Certification Research
Authors: Weiss Marianne , Johantgen Meg
Published: April 2022

OBJECTIVE

The aim of this study was to describe the scope and availability of certification data available for use in research about the value of specialty nurse certification.

BACKGROUND

Research about nurse certification and patient outcomes has been hindered by issues related to accuracy, completeness, reliability, and availability of certification data at the individual nurse level. An assessment of data elements and processes is needed to prepare recommendations about certification data standards.

METHODS

Electronic surveys were used to collect information about certification-related data elements and processes, and accessibility in practice settings that employ certified nurses and organizations that certify nurses.

RESULTS

One hundred thirty-six surveys were returned. Certification-related data are collected in many practice settings but with duplicative processes and distributed storage in multiple data systems. Varying data collection intervals and verification inconsistencies threaten data accuracy. Accessibility for research is a challenge.

CONCLUSIONS

Recommendations were developed to address each of the key findings of the study.
Self-proning in Nonintubated Patients with Coronavirus Disease 2019
Authors: Foster Mariah , Iseler Jackeline
Published: April 2022

Purpose/Objectives

The purpose of this article is to share observations one clinical nurse specialist noted after applying the concept of proning to treat acute respiratory distress syndrome in nonintubated patients with a confirmed or suspected diagnosis of coronavirus disease 2019 (COVID-19).

Description of the Project/Problem

Respiratory distress was a main symptom of many patients. However, hospitals were unable to meet the demand for automatic proning beds at the beginning of the pandemic, and no literature on prone positioning for nonintubated patients was published. One clinical nurse specialist identified self-proning as a means to improve respiratory distress, subsequently disseminating education and applying the practice with nonintubated patients with respiratory distress in the emergency department and throughout the COVID units in 1 hospital.

Outcome

Improved oxygenation saturation was observed by bedside staff after self-proning was implemented. Patients verbalized breathing easier while in the prone position. Patients were reminded to self-prone if their oxygenation saturations decreased. Self-proning afforded some patients enough stamina to call their loved ones before requiring intubation.

Conclusion

Through this observational experience, it was apparent that this low-risk intervention of nonintubated self-prone positioning improved oxygenation in patients with respiratory distress with a confirmed or suspected diagnosis of COVID-19.
Intensive Care Unit Nurses' Perceptions and Experience Using the American Heart Association Resuscitation Quality Improvement Program
Authors: Barile Lisa T. , McNiesh Susan , Walker-Vischer Lisa
Published: April 2022

Purpose/Aims

The aims of this clinical nurse specialist–led project were to describe the experiences and perceptions of adult intensive care unit nurses using the resuscitation quality improvement (RQI) program as the primary method for resuscitation education and retraining in a community hospital and to form recommendations for improving the RQI experience for participants based on the responses of participants as part of a quality improvement project.

Description of the Project

An online survey from a convenience sampling of registered nurses in an intensive care unit (N = 28) was done to obtain feedback regarding their perceptions of the RQI program. Analyses of the responses were performed separately by 3 investigators using principles of content analysis before obtaining consensus on themes to increase validity by triangulation.

Outcome

Themes emerged regarding the beneficial nature of the RQI program as a cardiopulmonary resuscitation learning strategy, such as increased frequency for the practice of compression and ventilation skills that included real-time feedback and increased knowledge of the roles of resuscitation team members. However, themes reflecting cumbersome aspects of using the RQI program were also revealed, such as technological and mechanical shortcomings, the structure of the manikins and ergonomics of the RQI environment, time away from patient care to complete RQI requirements, and lack of resuscitation team interactions.

Conclusion

Removing or mitigating barriers that hamper efficient use of nursing time using a quality improvement framework may enhance the RQI experience and program delivery, resulting in improved in-hospital cardiac arrest patient care.
Early Recognition, Prevention, and Management of Delirium in the Acute Care Setting
Authors: Hamilton Wendy , O'Neel Nicholas , Lacuzong Mariana , Lazarus Ann Marie , Johnson Peter , Gupta Amit
Published: April 2022

Purpose/Objectives

The purpose of this quality improvement initiative was to implement delirium screening, prevention, and management best practices in the non–critical care environment.

Description of the Project/Program

An interprofessional team at a 483-bed level 1 trauma center implemented a quality improvement initiative on one 24-bed medical ward and one 24-bed surgical ward. The 4 A's Test (4AT) screening tool was administered to patients with risk factors for delirium on admission, every shift, and as needed by nursing staff. Evidence-based prevention and management order sets were created by an interprofessional team to guide patient care planning processes.

Results

A total of 285 patients who were at high risk for delirium (100%) were screened using the 4AT tool. Forty-three of the 285 patients (15%) were positive on the 4AT screening or diagnosed with delirium, whereas 242 patients (85%) had a negative score on the 4AT. Delirium detection increased from 2.1% to 15% after implementing the 4AT. Fifty-six (19%) of the 285 high-risk patients had prevention order sets placed. Of the 43 patients who scored positive, 2 charts had management order sets placed.

Conclusion

A validated delirium screening tool and intervention order sets can increase early detection rates and provide staff with tools to prevent and manage delirium. The impact of this project will likely reduce preventable harm to patients and improve the quality of care that staff are able to provide in the medical-surgical acute care setting.
Pseudoprospective Paraclinical Interaction of Radiology Residents With a Deep Learning System for Prostate Cancer Detection
Authors: Zhang Kevin Sun , Schelb Patrick , Netzer Nils , Tavakoli Anoshirwan Andrej , Keymling Myriam , Wehrse Eckhard , Hog Robert , Rotkopf Lukas Thomas , Wennmann Markus , Glemser Philip Alexander , Thierjung Heidi , von Knebel Doeberitz Nikolaus , Kleesiek Jens , Görtz Magdalena , Schütz Viktoria , Hielscher Thomas , Stenzinger Albrecht , Hohenfellner Markus , Schlemmer Heinz-Peter , Maier-Hein Klaus , Bonekamp David
Published: April 2022

Objectives

The aim of this study was to estimate the prospective utility of a previously retrospectively validated convolutional neural network (CNN) for prostate cancer (PC) detection on prostate magnetic resonance imaging (MRI).

Materials and Methods

The biparametric (T2-weighted and diffusion-weighted) portion of clinical multiparametric prostate MRI from consecutive men included between November 2019 and September 2020 was fully automatically and individually analyzed by a CNN briefly after image acquisition (pseudoprospective design). Radiology residents performed 2 research Prostate Imaging Reporting and Data System (PI-RADS) assessments of the multiparametric dataset independent from clinical reporting (paraclinical design) before and after review of the CNN results and completed a survey. Presence of clinically significant PC was determined by the presence of an International Society of Urological Pathology grade 2 or higher PC on combined targeted and extended systematic transperineal MRI/transrectal ultrasound fusion biopsy. Sensitivities and specificities on a patient and prostate sextant basis were compared using the McNemar test and compared with the receiver operating characteristic (ROC) curve of CNN. Survey results were summarized as absolute counts and percentages.

Results

A total of 201 men were included. The CNN achieved an ROC area under the curve of 0.77 on a patient basis. Using PI-RADS ≥3-emulating probability threshold (c3), CNN had a patient-based sensitivity of 81.8% and specificity of 54.8%, not statistically different from the current clinical routine PI-RADS ≥4 assessment at 90.9% and 54.8%, respectively (P = 0.30/P = 1.0). In general, residents achieved similar sensitivity and specificity before and after CNN review. On a prostate sextant basis, clinical assessment possessed the highest ROC area under the curve of 0.82, higher than CNN (AUC = 0.76, P = 0.21) and significantly higher than resident performance before and after CNN review (AUC = 0.76 / 0.76, P ≤ 0.03). The resident survey indicated CNN to be helpful and clinically useful.

Conclusions

Pseudoprospective paraclinical integration of fully automated CNN-based detection of suspicious lesions on prostate multiparametric MRI was demonstrated and showed good acceptance among residents, whereas no significant improvement in resident performance was found. General CNN performance was preserved despite an observed shift in CNN calibration, identifying the requirement for continuous quality control and recalibration.
Assessing the Sensitivity of Dual-Energy Computed Tomography 3-Material Decomposition for the Detection of Gout
Authors: Tse Justin J. , Kondro Douglas A. , Kuczynski Michael T. , Pauchard Yves , Veljkovic Andrea , Holdsworth David W. , Frasson Viviane , Manske Sarah L. , MacMullan Paul , Salat Peter
Published: April 2022

Objectives

The aim of this study was to assess the accuracy and precision of a novel application of 3-material decomposition (3MD) with virtual monochromatic images (VMIs) in the dual-energy computed tomography (DECT) assessment of monosodium urate (MSU) and hydroxyapatite (HA) phantoms compared with a commercial 2-material decomposition (2MD) and dual-thresholding (DT) material decomposition methods.

Materials and Methods

Monosodium urate (0.0, 3.4, 13.3, 28.3, and 65.2 mg/dL tubes) and HA (100, 400, and 800 mg/cm3 tubes) phantoms were DECT scanned individually and together in the presence of the foot and ankle of 15 subjects. The raw data were decomposed with 3MD-VMI, 2MD, and DT to produce MSU-only and HA-only images. Mean values of 10 × 10 × 10–voxel volumes of interest (244 μm3) placed in each MSU and HA phantom well were obtained and compared with their known concentrations and across measurements with subjects' extremities to obtain accuracy and precision measures. A statistical difference was considered significant if P < 0.05.

Results

Compared with known phantom standards, 3MD-VMI was accurate for the detection of MSU concentrations as low as 3.4 mg/dL (P = 0.75). In comparison, 2MD was limited to 13.3 mg/dL (P = 0.06) and DT was unable to detect MSU concentrations below 65.2 mg/L (P = 0.16). For the HA phantom, 3MD-VMI and 2MD were accurate for all concentrations including the lowest at 100 mg/cm3 (P = 0.63 and P = 0.55, respectively). Dual-thresholding was not useful for the decomposition of HA phantom. Precision was high for both 3MD-VMI and 2MD measurements for both MSU and HA phantoms. Qualitatively, 3MD-VMI MSU-only images demonstrated reduced beam-hardening artifact and voxel misclassification, compared with 2MD and DT.

Conclusions

Three-material decomposition-VMI DECT is accurate for quantification of MSU and HA concentrations in phantoms and accurately detects a lower concentration of MSU than either 2MD or DT. For concentration measurements of both MSU and HA phantoms, 3MD-VMI and 2MD have high precision, but DT had limitations. Clinical implementation of 3MD-VMI DECT promises to improve the performance of this imaging modality for diagnosis and treatment monitoring of gout.
Cognitive Load Assessment Scales in Simulation
Authors: Greer Sara K. , Jeffe Donna B. , Manga Arushi , Murray David J. , Emke Amanda R.
Published: April 2022

Introduction

Cognitive load (CL) theory provides a framework to inform simulation instructional design. Reliable measures of CL types (intrinsic [IL], extraneous [EL], and germane load [GL]) in simulation are lacking. We developed the novel Cognitive Load Assessment Scales in Simulation (CLAS-Sim) and report validity evidence using Kane's framework.

Methods

This quasi-experimental study tested the effect of a segmented/pause-and-debrief or standard/end-of-case-debrief intervention on pediatric residents' performance and self-rated CL in 2 complex- and simple-case simulations. After each simulation, participants completed 22 items measuring CL types. Three validity inferences were examined: scoring (instrument development and principal component analysis); generalization (internal consistency reliability of CL-component items across cases); and extrapolation [CLAS-Sim correlations with the single-item Paas scale, which measures overall CL; differences in primary task performance (high vs low); and discriminant validity of IL under different instructional-design conditions].

Results

Seventy-four residents completed both simulations and postcase CLAS-Sim measures. The principal component analysis yielded 3 components: 4-item IL, 4-item EL, and 3-item GL scales (Cronbach's α, 0.68–0.77). The Paas scores correlated with CLAS-Sim IL and total CL scores in both cases (r
s range, 0.39–0.70; P ≤ 0.001). High complex-case performers reported lower IL and total CL (analyses of variance, each P < 0.001). In multivariate analyses of variance, CLAS-Sim IL, GL, and total CL varied across both cases by arm (each P ≤ 0.018); the segmented-debrief arm reported lower IL than the standard-debrief arm in both cases (each P ≤ 0.01).

Conclusions

The CLAS-Sim demonstrates preliminary validity evidence for distinguishing 3 CL types but requires further study to evaluate the impact of simulation-design elements on CL and learning.
Robust and efficient identification of optimal mixing perturbations using proxy multiscale measures
Authors: Heffernan Conor , Caulfield Colm-cille P.
Published: April 2022

Understanding and optimizing passive scalar mixing in a diffusive fluid flow at finite Péclet numberPe=Uh/κ(whereUandhare characteristic velocity and length scales, andκis the molecular diffusivisity of the scalar) is a fundamental problem of interest in many environmental and industrial flows. Particularly whenPe≫1, identifying initial perturbations of given energy that optimally and thoroughly mix fluids of initially different properties can be computationally challenging. To address this challenge, we consider the identification of initial perturbations in an idealized two-dimensional flow on a torus that extremize various measures over finite time horizons. We identify such ‘optimal’ initial perturbations using the ‘direct-adjoint looping’ method, thus requiring the evolving flow to satisfy the governing equations and boundary conditions at all points in space and time. We demonstrate that minimizing multiscale measures commonly known as ‘mix-norms’ over short time horizons is a computationally efficient and robust way to identify initial perturbations that thoroughly mix layered scalar distributions over relatively long time horizons, provided the magnitude of the mix-norm’s index is not too large. Minimization of such mix-norms triggers the development of coherent vortical flow structures which effectively mix, with the particular properties of these flow structures depending onPeand also the time horizon of interest.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Open-flow mixing and transfer operators
Authors: Klünker Anna , Padberg-Gehle Kathrin , Thiffeault Jean-Luc
Published: April 2022

We study finite-time mixing in time-periodic open flow systems. We describe the transport of densities in terms of a transfer operator, which is represented by the transition matrix of a finite-state Markov chain. The transport processes in the open system are organized by the chaotic saddle and its stable and unstable manifolds. We extract these structures directly from leading eigenvectors of the transition matrix. We use different measures to quantify the degree of mixing and show that they give consistent results in parameter studies of two model systems.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Stokes drift and its discontents
Authors: Vanneste Jacques , Young William R.
Published: April 2022

The Stokes velocity

u

S

, defined approximately by Stokes (1847,
Trans. Camb. Philos. Soc.
,
8
, 441–455.), and exactly via the Generalized Lagrangian Mean, is divergent even in an incompressible fluid. We show that the Stokes velocity can be naturally decomposed into a solenoidal component,

u

sol

S

, and a remainder that is small for waves with slowly varying amplitudes. We further show that

u

sol

S

arises as the sole Stokes velocity when the Lagrangian mean flow is suitably redefined to ensure its exact incompressibility. The construction is an application of Soward & Roberts’s glm theory (2010,
J. Fluid Mech.
,
661
, 45–72. (
doi:10.1017/S0022112010002867
)) which we specialize to surface gravity waves and implement effectively using a Lie series expansion. We further show that the corresponding Lagrangian-mean momentum equation is formally identical to the Craik–Leibovich (CL) equation with

u

sol

S

replacing

u

S

, and we discuss the form of the Stokes pumping associated with both

u

S

and

u

sol

S

.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Velocity-informed upper bounds on the convective heat transport induced by internal heat sources and sinks
Authors: Bouillaut Vincent , Flesselles Benoît , Miquel Benjamin , Aumaître Sébastien , Gallet Basile
Published: April 2022

Three-dimensional convection driven by internal heat sources and sinks (CISS) leads to experimental and numerical scaling laws compatible with a mixing-length—or ‘ultimate’—scaling regime

N
u
∼

R
a

. However, asymptotic analytic solutions and idealized two-dimensional simulations have shown that laminar flow solutions can transport heat even more efficiently, with

N
u
∼
R
a

. The turbulent nature of the flow thus has a profound impact on its transport properties. In the present contribution, we give this statement a precise mathematical sense. We show that the Nusselt number maximized over all solutions is bounded from above by

const.
×
R
a

, before restricting attention to ‘fully turbulent branches of solutions’, defined as families of solutions characterized by a finite non-zero limit of the dissipation coefficient at large driving amplitude. Maximization of

N
u

over such branches of solutions yields the better upper-bound

N
u
≲

R
a

. We then provide three-dimensional numerical and experimental data of CISS compatible with a finite limiting value of the dissipation coefficient at large driving amplitude. It thus seems that CISS achieves the maximal heat transport scaling over fully turbulent solutions.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
The background method: theory and computations
Authors: Fantuzzi Giovanni , Arslan Ali , Wynn Andrew
Published: April 2022

The background method is a widely used technique to bound mean properties of turbulent flows rigorously. This work reviews recent advances in the theoretical formulation and numerical implementation of the method. First, we describe how the background method can be formulated systematically within a broader ‘auxiliary function’ framework for bounding mean quantities, and explain how symmetries of the flow and constraints such as maximum principles can be exploited. All ideas are presented in a general setting and are illustrated on Rayleigh–Bénard convection between stress-free isothermal plates. Second, we review a semidefinite programming approach and a timestepping approach to optimizing bounds computationally, revealing that they are related to each other through convex duality and low-rank matrix factorization. Open questions and promising directions for further numerical analysis of the background method are also outlined.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Optimal cooling of an internally heated disc
Authors: Tobasco Ian
Published: April 2022

Motivated by the search for sharp bounds on turbulent heat transfer as well as the design of optimal heat exchangers, we consider incompressible flows that most efficiently cool an internally heated disc. Heat enters via a distributed source, is passively advected and diffused, and exits through the boundary at a fixed temperature. We seek an advecting flow to optimize this exchange. Previous work on energy-constrained cooling with a constant source has conjectured that global optimizers should resemble convection rolls; we prove one-sided bounds on energy-constrained cooling corresponding to, but not resolving, this conjecture. In the case of an enstrophy constraint, our results are more complete: we construct a family of self-similar, tree-like ‘branching flows’ whose cooling we prove is within a logarithm of globally optimal. These results hold for general space- and time-dependent source–sink distributions that add more heat than they remove. Our main technical tool is a non-local Dirichlet-like variational principle for bounding solutions of the inhomogeneous advection–diffusion equation with a divergence-free velocity.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Relationship between the methods of bounding time averages
Authors: Chernyshenko Sergei
Published: April 2022

The problem of finding bounds of time-averaged characteristics of dynamical systems, such as the bound on the mean energy dissipation rate in a turbulent flow governed by incompressible Navier–Stokes equations, is considered. It is shown that the direct method described by Seis (2015
J. Fluid Mech.
777
, 591–603. (
doi:10.1017/jfm.2015.384
)) and the auxiliary functional method by Chernyshenko
et al.
(2014
Phil. Trans. R. Soc. B
372
, 20130350. (
doi:10.1098/rsta.2013.0350
)) are related and can lead to the same bound. The well-known background flow method of Doering and Constantin is equivalent to the auxiliary functional method with a quadratic auxiliary functional. The known implementations of the direct method apparently also correspond to quadratic auxiliary functionals. The findings are illustrated by the analysis of the plane Couette flow. Three routes of further progress using non-quadratic auxiliary functionals and at the same time allowing to use the experience accumulated with the background flow method are proposed: making the balance parameter dependent on the energy, making the background flow time-dependent in a specific way and adding helicity to the auxiliary functional.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 1)’.
Genetic polymorphism of Plasmodium falciparum msp-1, msp-2 and glurp vaccine candidate genes in pre-artemisinin era clinical isolates from Lakhimpur district in Assam, Northeast India
Authors: Sathishkumar Vinayagam , Nirmolia Tulika , Bhattacharyya Dibya Ranjan , Patgiri Saurav Jyoti
Published: April 2022

Background. Northeast India shares its international border with Southeast Asia and has a number of malaria endemic zones. Monitoring genetic diversity of malaria parasites is important in this area as drug resistance and increasing genetic diversity form a vicious cycle in which one favours the development of the other. This retrospective study was done to evaluate the genetic diversity patterns in Plasmodium falciparum strains circulating in North Lakhimpur area of Assam in the pre-artemisinin era and compare the findings with current diversity patterns.

Methods.Genomic DNA extraction was done from archived blood spot samples collected in 2006 from malaria-positive cases in Lakhimpur district of Assam, Northeast India. Three antigenic markers of genetic diversity were studied – msp-1 (block-2), msp-2 (block-3) and the glurp RII region of P. falciparum using nested PCR.

Results. Allelic diversity was examined in 71 isolates and high polymorphism was observed. In msp-1, eight genotypes were detected; K1 (single allele), MAD20 (six different alleles) and RO33 (single allele) allelic families were noted. Among msp-2 genotypes, 22 distinct alleles were observed out of which FC27 had six alleles and IC/3D7 had 16 alleles. In RII region of glurp, nine genotypes were obtained. Expected heterozygosity (H
E) values of the three antigenic markers were 0.72, 0.81 and 0.88, respectively. Multiplicity of infection (MOI) values noted were 1.28, 1.84 and 1.04 for msp-1, msp-2 and glurp, respectively.

Conclusion. Results suggest a high level of genetic diversity in P. falciparum msp (block-2 of msp-1 and block-3 of msp-2) and the glurp RII region in Northeast India in the pre-artemisinin era when chloroqunine was the primary drug used for uncomplicated falciparum malaria. Comparison with current studies have revealed that the genetic diversity in these genes is still high in this region, complicating malaria vaccine research.
Paenalcaligenes niemegkensis sp. nov., a novel species of the family Alcaligenaceae isolated from plastic waste
Authors: Mitzscherling Julia , MacLean Joana , Lipus Daniel , Bartholomäus Alexander , Mangelsdorf Kai , Lipski André , Roddatis Vladimir , Liebner Susanne , Wagner Dirk
Published: April 2022

Strain NGK35T is a motile, Gram-stain-negative, rod-shaped (1.0–2.1 µm long and 0.6–0.8 µm wide), aerobic bacterium that was isolated from plastic-polluted landfill soil. The strain grew at temperatures between 6 and 37 °C (optimum, 28 °C), in 0–10 % NaCl (optimum, 1 %) and at pH 6.0–9.5 (optimum, pH 7.5–8.5). It was positive for cytochrome c oxidase, catalase as well as H2S production, and hydrolysed casein and urea. It used a variety of different carbon sources including citrate, lactate and pyruvate. The predominant membrane fatty acids were C16 : 1 cis9 and C16 : 0, followed by C17 : 0 cyclo and C18 : 1 cis11. The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine, followed by diphosphatidyglycerol. The only quinone was ubiquinone Q-8. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK35T belongs to the genus

Paenalcaligenes

(family

Alcaligenaceae

), appearing most closely related to

Paenalcaligenes hominis

CCUG 53761AT (96.90 %) and

Paenalcaligenes suwonensis

ABC02-12T (96.94 %). The genomic DNA G+C content of strain NGK35T was 52.1 mol %. Genome-based calculations (genome-to-genome distance, average nucleotide identity and DNA G+C content) clearly indicated that the isolate represents a novel species within the genus

Paenalcaligenes

. Based on phenotypic and molecular characterization, strain NGK35T can clearly be differentiated from its phylogenetic neighbours establishing a novel species, for which the name Paenalcaligenes niemegkensis sp. nov. is proposed. The type strain is NGK35T (=DSM 113270T=NCCB 100854T).
Exploring learning outcomes for managers who coach
Authors: Adele Beth , Ellinger Andrea D. , McWhorter Rochell R. , Egan Toby M.
Published: April 2022

Purpose

As a part of a larger study, the purpose of this study was to explore the learning outcomes for the “manager as coach” when exemplary managers are engaged in coaching their respective employees.

Design/methodology/approach

A qualitative, multi-case study using an adaptation of the critical incident technique (CIT) and semistructured interviews was employed with 12 managers and their respective direct reports totaling 24 interviews. Content and constant comparative analyses were used to analyze the data.

Findings

A total of five themes and 19 subthemes were identified regarding managers’ learning outcomes from managers’ perspectives. From the perspectives of their employees as coachees regarding their managers’ learning outcomes, one theme with three subthemes emerged.

Originality/value

Limited empirical research has explored the developmental outcomes for managers who serve as coaches for their employees. This study examined the outcomes associated with managerial coaching from both the perspectives of the managers who coach and their direct reports. The findings of this research provide more insight into the benefits managers derive from coaching their employees.
Taking a conflict perspective to explain an employee’s creativity
Authors: Adamovic Mladen
Published: April 2022

Purpose

A dynamic and changing international business environment and higher needs for innovation have increased the importance of creativity in organizations. Organizations need creative employees to develop new methods and procedures that stimulate innovation. However, prior research indicates that employees are sometimes passive and avoid engaging in creative behavior. To promote individual creative behavior, this study aims to better understand the role of task conflict and conflict management. More specifically, the authors draw on Deutsch’s conflict theory of cooperation and competition to test whether an employee’s conflict management moderates the indirect relationship between task conflict and creativity through cooperation.

Design/methodology/approach

To test the hypotheses, the authors conducted a three-phase survey study with 428 employees from different German organizations.

Findings

The results suggest that task conflict has only a positive indirect relationship with creativity through cooperation with teammates when employees avoid a competitive conflict management style.

Originality/value

The authors draw on Deutsch’s conflict theory of cooperation and competition to integrate research on task conflict and conflict management, allowing them to explain why and when task conflict with teammates influences an employee’s creativity. The findings show that task conflict is particularly beneficial for cooperation and creativity if employees avoid closed-minded discussions and competitive interactions with coworkers.
Wealth-induced child labour: evidence from Ethiopia
Authors: Hailu Ziade , Girma Tilahun
Published: April 2022

Purpose

This study aims to empirically test the variation in household assets and the incidence of child labour using data from Ethiopia.

Design/methodology/approach

The study was cross-sectional in design and used a sample of 3,500 observations (children aged 5–17 years) collected from 2,231 households in the rural and urban areas of Amhara and Southern Nations, Nationalities, and Peoples' regions in Ethiopia. The logistic regression model was used to estimate the extent to which predictor variables are associated with the incidence of child labour.

Findings

The results indicate statistically significant child labour participation by those households who own assets than those who do not. The findings suggest that parents who own assets such as land, livestock and other endowments are likely to employ children in labour than the opposite, i.e. child labour increases with household asset ownership. However, this study did not investigate child labour response to wealth increment at the individual household level.

Practical implications

Any initiative to reduce child labour needs to be accompanied by parental awareness and compulsory schooling as one of the key policy tools.

Originality/value

This is one of those studies that question the poverty assumption as a cause of child labour and suggests parental selfishness playing a role in accentuating child labour.
Sustainability in management undergraduate courses: mapping the Brazilian higher education institutions
Authors: Galleli Barbara , Teles Noah Emanuel Brito , Freitas-Martins Mateus Santos , Semprebon Elder , Hourneaux Junior Flavio
Published: April 2022

Purpose

This study aims to analyse the insertion of Sustainability in Management undergraduate courses in Brazilian higher education institutions (HEIs).

Design/methodology/approach

Through content analysis, the authors have mapped the curricular grids of the Management courses simultaneously best classified in an independent national ranking and with the highest scores in the Brazilian Government’s assessment instruments. Afterwards, the authors carried out both network and cluster analyses.

Findings

Among the main findings, the authors can highlight the exclusive presence of public universities in the sample, the absence of courses that offer sustainability themes in the Amazon region, the high incidence of Sustainability in elective courses, the prominence of themes related only to the environmental dimension of Sustainability and the considerable difference among the five regions of the country in terms of the content offers. Given these findings, the authors can state that Sustainability via curricular insertion in the studied undergraduate courses in Management is still in its initial stages. The study sheds light on how the Management curriculum can embed Sustainability and provides insights for dealing with this issue in educational policies, both at local and national levels.

Practical implications

The study confirms that the insertion of Sustainability via curriculum in the undergraduate courses in Management is still in its initial stages and discusses how different Sustainability contents are related or not to their context.

Originality/value

This study contributes to the theme of Sustainability in HEIs by conveying structured and comprehensive data, besides contributing to studies on the topic in emerging countries, particularly in Latin America.
More than feelings? How Facebook reaction icons affect online users' behavioral intentions toward online health rumor posts
Authors: Hou Jian-Ren , Kankham Sarawut
Published: April 2022

Purpose

When the spread of online health rumors on social media causes public concerns, the public is calling for action. However, little study has investigated how Facebook reaction icons (expressing feelings function) affect online users' behavioral intentions (intention to trust and share) toward online health rumor posts. The current study addresses this gap by focusing on the effect of Facebook reaction icons in two conditions: Facebook reaction icons' presence (versus absence), and Facebook reaction icons' emotional valence (positive versus negative versus neutral). Moreover, the authors also investigated the interaction between Facebook reaction icons' emotional valence and online health rumor posts' framing headlines (gain versus loss).

Design/methodology/approach

The authors used a 7 (Facebook reaction icons: Love, Like, Haha, Wow, Sad, Angry and no icon) × 2 (Facebook framing headlines: gain and loss) between-subjects design, analyzing 507 samples from online users with one-way ANOVA and MANOVA.

Findings

Results show that online health rumor posts without Facebook reaction icons are more likely to negatively change online users' behavioral intentions than the posts with Facebook reaction icons; negative reaction icons (Sad and Angry) lower online users' behavioral intentions than positive reaction icons (Love and Like). Further, the incongruency effect of interaction (i.e. positive reaction icons with a negative message) would have more negative effects on online users' behavioral intentions than the congruency effect (i.e. positive reaction icons with a positive message).

Originality/value

This study has rich contributions to theoretical and practical implications for the Facebook platform and Facebook users to apply Facebook reaction icons against online health rumor posts.
Burdening effect of Shariah knowledge and sales performance in Islamic financial institutions: does female salesforce perform better?
Authors: Shamsudheen Shinaj Valangattil , Mahomed Ziyaad
Published: April 2022

Purpose

The purpose of this paper is to examine the burdening effect of Shariah knowledge on the sales performance of salesforce in Islamic financial institutions with special reference to gender heterogeneity.

Design/methodology/approach

A total of 324 responses were collected from salesforce in Islamic financial institutions of Malaysia, and empirical assessment was conducted with the measures of model fit and bootstrapping techniques using partial least square multi-group analysis.

Findings

Empirical findings indicate that burdening effect is evident among salesforce, and the intensity of burdening effect is relatively lesser in female salesforce compared to male salesforce. Empirical findings suggest that respective authorities of Islamic financial institutions to intensify capacity building for their salesforce, particularly in the area where the Shariah knowledge and nature of underlying Islamic contracts are employed in the financial products.

Practical implications

There is a significant competitive advantage in preferring more female salesforce to improve the slow growth of the industry that results from burdening effect of Shariah knowledge. Not least of all, it is highly recommended for Islamic financial institutions to provide more training for the male salesforce to overcome the issue of information overload in sales performance.

Originality/value

While there is ample literature documented that examines the gender effect in conventional sales and marketing discipline, little emphasis has been given to the salesforce in the Islamic finance industry. Further, the findings of this study provide vital implications for the management in formulating crucial policies with respect to the salesforce preference and capacity building in dealing with the burdening effect of peculiar features of the Shariah knowledge in the light of the ongoing slow growth of the Islamic finance industry.