bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooperative beamforming for a double-IRS-assisted wireless communication system
Authors: Tian Guodong , Song Rongfang
Published: August 2021

Intelligent reflecting surface (IRS) has emerged as an innovative and disruptive solution to boost the spectral and energy efficiency and enlarge the coverage of wireless communication systems. However, the existing literature on IRS mainly concentrates on wireless communication systems assisted by single or multiple distributed IRSs, which are not always effective. In view of this issue, this paper considers a special double-IRS-assisted wireless communication system, where IRS1 and IRS2 are deployed near the base station (BS) and the user, respectively, and the transmitted signals reach the user via the cascaded BS-IRS1-IRS2-user channel only. We cooperatively optimize transmit and passive beamforming on the two IRSs based on the particle swarm optimization (PSO) algorithm to maximize the received signal power. Simulation indicates that despite no direct line-of-sight (LoS) path from the BS to the user, an excellent signal-to-noise ratio (SNR) is available at the receiver with the aid of two IRSs, which demonstrates that it is feasible to assist communication by double reflection links composed of two IRSs. Additionally, we unexpectedly find that when the positions of the two IRSs are fixed, by exchanging the positions of the BS and the user, the obtainable SNRs are similar.
Trajectory tracking control of AGV based on time-varying state feedback
Authors: Shang Jin , Zhang Jian , Li Chengchun
Published: August 2021

In order to realize the automation of transport equipment, according to the automatic guided vehicle (AGV) kinematics model, the trajectory tracking control of AGV with front wheel steering and rear wheel drive is studied. Lyapunov function is used to ensure the global stability of the system. Time-varying state feedback method based on integral backstepping is adopted, introducing virtual feedback, a trajectory tracking controller for AGV with nonholonomic constraints is proposed. In order to ensure the smooth motion of AGV, the speed and acceleration limited strategy of AGV is introduced into the controller. Simulation results show that the algorithm is fast, accurate and globally stable for different paths.
Association between occupational exposures and sarcoma incidence and mortality: systematic review and meta-analysis
Authors: Edwards D. , Voronina A. , Attwood K. , Grand’Maison A.
Published: August 2021

Background

Sarcomas are a rare and heterogeneous group of tumors originating from mesenchymal or connective tissue. They represent less than 1% of all adult cancers. The etiology and epidemiology of sarcomas remain understudied and poorly understood. The main objective of our study was to systematically assess the association between various occupational exposures and risk of sarcomas.

Methods

We performed a systematic literature search using the PubMed, Scopus, EMBASE and Cochrane databases to identify relevant cohort and case–control studies. A meta-analysis method was applied on the incidence and mortality outcomes where the estimate with 95% confidence interval (CI) was obtained.

Results

We included a total of 50 publications in our systematic review and 35 in meta-analysis. For exposures to phenoxy herbicides and chlorophenols, the pooled odds ratio (OR) for sarcoma was 1.85 (95% CI: 1.22, 2.82), based on 16 studies with 2254 participants, while the pooled standardized mortality ratio was 40.93 (95% CI 2.19, 765.90), based on 4 cohort studies with 59,289 participants. For exposure to vinyl chloride monomers the pooled risk ratios for angiosarcoma of the liver and other STS were 19.23 (95% CI 2.03, 182.46) and 2.23 (95 CI 1.55, 3.22) respectively based on 3 cohort studies with 12,816 participants. Exposure to dioxins was associated with an increased STS mortality; the pooled standardized mortality ratio was 2.56 (95% CI 1.60, 4.10) based on 4 cohort studies with 30,797 participants. Finally, woodworking occupation was associated with an increased risk of STS with the pooled OR of 2.16 (95% CI 1.39, 3.36).

Conclusions

Our findings suggest a positive association between higher exposure to dioxins and increased mortality from STS, between cumulative exposure to vinyl chloride monomers and increased mortality from angiosarcoma of the liver and STS, and between woodworking occupation and STS incidence. These findings were all statistically significant.
Plant developmental stage drives the differentiation in ecological role of the maize microbiome
Authors: Xiong Chao , Singh Brajesh K. , He Ji-Zheng , Han Yan-Lai , Li Pei-Pei , Wan Li-Hua , Meng Guo-Zhong , Liu Si-Yi , Wang Jun-Tao , Wu Chuan-Fa , Ge An-Hui , Zhang Li-Mei
Published: August 2021

Background

Plants live with diverse microbial communities which profoundly affect multiple facets of host performance, but if and how host development impacts the assembly, functions and microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils, epiphytic and endophytic niches of leaf and root, and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.

Results

Our results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartments than in soils, with the strongest effect in the phylloplane. Phylloplane microbiomes were co-shaped by both plant growth and seasonal environmental factors, with the air (represented by fake plants) as its important source. Further, we found that bacterial communities in plant compartments were more strongly driven by deterministic processes at the early stage but a similar pattern was for fungal communities at the late stage. Moreover, bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity at the early stage than the late stage, with functional genes related to nutrient provision enriched at the early stage and N assimilation and C degradation enriched at the late stage. Coincidently, more abundant beneficial bacterial taxa like Actinobacteria, Burkholderiaceae and Rhizobiaceae in plant microbiomes were observed at the early stage, but more saprophytic fungi at the late stage.

Conclusions

Our results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different stages of plant development. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection during plant growth and development. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity.
A mixed methods exploratory evaluation of burnout in frontline staff implementing dialectical behavior therapy on a pediatric eating disorders unit
Authors: Couturier Jennifer , Ma Zechen , Rahman Liah , Webb Cheryl
Published: August 2021

Background

Eating disorders are life-threatening illnesses that commonly affect adolescents. The treatment of individuals with eating disorders can involve slow treatment progression and addressing comorbidities which can contribute to staff burnout. Dialectical behavior therapy (DBT) has emerged as a viable treatment option and has reduced staff burnout in several other settings. Our aim was to describe frontline staff burnout using mixed methodology on a DBT-trained combined inpatient/day hospital unit for pediatric eating disorders.

Method

Frontline staff were trained to provide DBT skills for adolescents with eating disorders. Twelve months following the training and implementation, they completed the Copenhagen Burnout Inventory (CBI) and a qualitative interview. Directed and summative content analyses were used.

Results

Eleven frontline staff including nurses, child life specialists and child and youth workers participated. The CBI revealed that only one staff member experienced high personal burnout, while another experienced high client-related burnout. Qualitative data indicated that all frontline staff felt DBT had the potential to reduce burnout.

Conclusion

Qualitative data indicate that staff believe that DBT may hold promise in reducing burnout for pediatric frontline staff who treat children and adolescents with eating disorders. Further study is needed.

Plain English summary

Understanding burnout is particularly important for nursing staff in inpatient and day hospital settings for eating disorders, as nursing staff generally have the most frequent patient contact; thought to be a risk factor for burnout. The reduction of burnout can prevent detrimental effects on job performance, personal well-being, and patient outcomes. Our exploratory study shows that frontline staff believe that DBT may have the potential to reduce burnout in staff treating children and adolescents with eating disorders in a combined inpatient/day hospital setting. Further study is needed in this area.
Virtual cleaning of works of art using deep convolutional neural networks
Authors: Maali Amiri Morteza , Messinger David W
Published: August 2021

A varnish layer that is applied to a painting, generally to protect it, yellows over time, deteriorating the original look of the painting. This prompts conservators to undertake a cleaning process to remove the old varnish and apply a new one. Providing the conservators with the likely appearance of the painting before the cleaning process starts can be helpful to them, which can be done through virtual cleaning. Virtual cleaning is simply the simulation of the cleaning process. Previous works in this area required the method to have access to black and white paint regions, or physically removing the varnish first at a few spots. Through looking at the problem of virtual cleaning differently, we try to address those shortcomings. To do so, we propose using a convolutional neural network (CNN) to tackle the problem of virtual cleaning. The CNN is trained on artificially yellowed images of people, urban and rural areas, and color charts, as well as their original versions. The network is then applied to various paintings with similar scene content. The results of the method are first compared to the only physical model in the virtual cleaning field. We compare the outputs from the proposed method and the physical model by visualization as well as a quantitative measure that calculates the spectral similarity between the outputs and the reference images. These results show that the proposed method outperforms the physical model. The CNN is also applied to images of the Mona Lisa and The Virgin and Child with Saint Anne, both painted by Leonardo da Vinci. Results show both a qualitative and quantitative improvement in the color quality of the resulting image compared to their reference images. The CNN developed here is also compared to a CNN that has been developed for the purpose of image colorization in the literature to demonstrate the effectiveness of the CNN devised here, showing that the CNN architecture herein leads to a better result. The novelty of the work proposed herein lies in two premises. First, the accuracy of the method, which is demonstrated through comparison with the only physical approach derived until now. Second is the generalizability of the method which is shown through blindly applying the method to two famous works of art for which no information but an RGB image of the uncleaned artwork is known.
The impact of first and second wave of COVID-19 on knee and hip surgeries in Sweden
Authors: Dell’Isola Andrea , Kiadaliri Ali , Turkiewicz Aleksandra , Hughes Velocity , Magnusson Karin , Runhaar Jos , Bierma-Zeinstra Sita , Englund Martin
Published: August 2021

Purpose

To investigate the impact of COVID-19 in Sweden on rates of knee and hip surgeries.

Methods

We used healthcare data for the population of the southernmost region in Sweden (1.4 million inhabitants). We did an interrupted time-series analysis to estimate changes in rates and trends of joint replacements (JR), arthroscopies, and fracture surgeries for knee or hip in April–December 2020 compared to pre-COVID-19 levels adjusting for seasonal variations.

Results

We found a drop of 54% (95% CI 42%; 68%) and 42% (95% CI 32%; 52%), respectively, in the rate of JRs and arthroscopies in April 2020 when compared to the counterfactual scenario. This was followed by an increase that brought the rates of JRs and arthroscopies back to their predicted levels also during the beginning of the second wave (November–December 2020). Acute fracture surgeries were largely unaffected, i.e. did not show any decrease as observed for the other surgeries.

Conclusions

In southern Sweden, we observed a marked decrease in elective knee and hip surgeries following the first wave of Covid-19. The rates remained close to normal during the beginning of the second wave suggesting that important elective surgeries for patients with end-stage osteoarthritis can still be offered despite an ongoing pandemic provided adequate routines and hospital resources.
Operationalization of self-regulation in the early years: comparing policy with theoretical underpinnings
Authors: Braund Heather , Timmons Kristy
Published: August 2021

Research has consistently demonstrated that self-regulation is essential for the development and preservation of health and well-being in the early years and across the lifespan. Based on the emerging literature on the important role of self-regulation in promoting healthy child development, policymakers have made efforts to include self-regulation skills in practice and policy documents worldwide. Despite efforts to include self-regulation skills in early years curriculum documents, there is limited understanding by teachers, scholars, and policymakers of what self-regulation is and how best to support it in the day-to-day classroom. This limited understanding is perpetuated by a lack of a unified definition of self-regulation. Thus, it becomes important to examine these efforts in a critical way. In Ontario, where the research was completed, a revised play-based full-day kindergarten program was introduced in 2016. In this research we use a qualitative document analysis approach to compare the conceptualization of self-regulation in Ontario’s revised play-based kindergarten program with theory-driven models of self-regulation from empirical research. Analysis was iterative, and themes emerged based upon a coding scheme developed by the research team. Results suggest that co-regulation has a powerful influence on student learning. In addition, the policy document de-emphasizes behavioral regulation and expands cognitive regulation to include more than inhibitory control. Lastly, the kindergarten program discusses metacognition in relation to the use of language to articulate one’s thinking with little attention to goal-directed behaviors. In this paper, explicit recommendations for policymakers and practitioners are provided to ensure that emerging conceptualizations of self-regulation are promoted in early years curricula. Further, empirical evidence is needed to support why it is necessary to understand emerging conceptualizations of self-regulation and outline implications for current early years curricula.
Severe methanol poisoning treated with a novel hemodialysis system: a case report, analysis, and review
Authors: Illescas Alisa C. , Argyropoulos Christos P. , Combs Sara A. , Shaffi Saeed K. , Xu Zhi Q. , Aragon Michael A. , Teixeira J. Pedro
Published: August 2021

In May and June 2020, an outbreak of methanol poisoning arose in the southwest United States linked to ingestion of contaminated hand sanitizer imported during the coronavirus disease 2019 pandemic, ultimately resulting in over a dozen hospitalizations and at least four deaths in New Mexico and Arizona. In this report, we describe one of these cases in which profound methanol intoxication was successfully treated with the Tablo® Hemodialysis System, the first reported case of toxic alcohol poisoning treated with this novel device. We carry out a formal regression analysis of the serial methanol levels obtained in this case to conservatively estimate that intermittent hemodialysis with Tablo achieved a clearance of methanol of 239 mL/min (95% confidence interval, 173–305 mL/min), a clearance that is well within the previously published standard of care. We conclude by reviewing both the treatment of toxic alcohol poisoning and the determinants of small molecule clearance with hemodialysis, emphasizing the importance of optimizing the dialytic treatment of intoxications with extended treatment times and the use of high-efficiency dialyzers.
Role of contrast-enhanced FLAIR MRI in diagnosis of intracranial lesions
Authors: Mustafa Wessam , Ali Sherif , Elgendy Nadia , Salama Samer , El Sorogy Lamiaa , Mohsen Mohamed
Published: August 2021

Background

MR imaging plays a significant role in detection and characterization of different brain diseases. The role of the post-contrast T1-weighted image magnetic resonance imaging (T1W MRI) sequence has been widely established in previous studies and clinical practice. In this study, we aim to share our experience as regards the added value of contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) sequence in the diagnosis of various intracranial pathological conditions and evaluate its usefulness in comparison with post-contrast T1W images.

Results

Based on the final radiological diagnosis, the total cases were subdivided into three categories, and the majority of our cases were tumors (81.2%), followed by multiple sclerosis (11.8%), and the least was central nervous system infection (7.1%). CE-FLAIR showed superior enhancement in 35 cases (50.7) and equal enhancement in 25 cases (36.3%). However, it showed less enhancement than post-contrast T1W images in 9 cases (13%). Excellent inter-observer agreement (97.65%) was noted. Regarding lesion conspicuity, good delineation was found in the majority of cases (64.7%), fair delineation in 12.9%, and no delineation in 22.4%. A statistically significant difference was found in signal intensity of lesion between pre- and post-contrast FLAIR sequences. Contrast to background ratio was statistically significant in CE FLAIR images in comparison to CE T1 images.

Conclusion

CE-FLAIR imaging should be used as a routine or adjunctive sequence to CE-T1WI to enhance early detection and increase the diagnostic confidence in MRI examination of different brain pathological conditions.
Impact of videoconferencing applications on mental health
Authors: Mamtani Harkishan , Karaliuniene Ruta , de Filippis Renato , Nagendrappa Sachin
Published: August 2021

Under the circumstances of the current COVID-19 pandemic, videoconferencing applications (apps) have come into the mainstream across the world. Owing to their easy availability and cost-effectiveness, they are used in personal as well as professional lives to communicate. They have been very helpful for students and professionals to ensure that their routine work did not halt when various countries imposed lockdown rules restricting travel, social gatherings and other measures that resulted in reduced in-person meetings. However, they have their own set of disadvantages, aptly called ‘Zoom gloom/fatigue’, named after a popular videoconferencing platform. Users are also noted to have anxiety while using these apps. Therefore, immediate attention is warranted to ensure cautious usage and to reduce the distress associated with videoconferencing apps while maintaining the obvious advantages that these methods have rapidly spread all over the world.
Combining Ixazomib With Subcutaneous Rituximab and Dexamethasone in Relapsed or Refractory Waldenström's Macroglobulinemia: Final Analysis of the Phase I/II HOVON124/ECWM-R2 Study
Authors: Kersten Marie José , Amaador Karima , Minnema Monique C. , Vos Josephine M. I. , Nasserinejad Kazem , Kap Marcel , Kastritis Efstathios , Gavriatopoulou Maria , Kraan Willem , Chamuleau Martine E. D. , Deeren Dries , Tick Lidwine W. , Doorduijn Jeanette K. , Offner Fritz , Böhmer Lara H. , Liu Roberto D. , Pals Steven T. , Dimopoulos Meletios A.
Published: August 2021

PURPOSE

Proteasome inhibitors are effective in Waldenström's macroglobulinemia (WM) but require parenteral administration and are associated with polyneuropathy. We investigated efficacy and toxicity of the less neurotoxic oral proteasome inhibitor ixazomib combined with rituximab, in patients with relapsed WM.

METHODS

We conducted a multicenter phase I/II trial with ixazomib, rituximab, and dexamethasone (IRD). Induction consisted of eight cycles IRD wherein rituximab was started in cycle 3, followed by rituximab maintenance. Phase I showed feasibility of 4 mg ixazomib. Primary end point for phase II was overall response rate (ORR [≥ minimal response]) after induction.

RESULTS

A total of 59 patients were enrolled (median age, 69 years; range, 46-91 years). Median number of prior treatments was 2 (range, 1-7); 70% had an intermediate or high WM-IPSS (International Prognostic Scoring System for WM) score. After eight cycles, ORR was 71% (42 out of 59) (14% very good partial response [PR], 37% PR, and 20% minor response). Depth of response improved until month 12 (best ORR 85% [50 out of 59]: 15% very good PR, 46% PR, and 24% minor response). Median duration of response was 36 months. The average hematocrit level increased significantly (0.33-0.38 L/L) after induction ( P < .001). After two cycles of ixazomib and dexamethasone, immunoglobulin M levels decreased significantly (median 3,700-2,700 mg/dL, P < .0001). Median time to first response was 4 months. Median progression-free survival and overall survival were not reached. After median follow-up of 24 months (range, 7.4-54.3 months), progression-free survival and overall survival were 56% and 88%, respectively. Toxicity included mostly grade 2 or 3 cytopenias, grade 1 or 2 neurotoxicity, and grade 2 or 3 infections. No infusion-related reactions or immunoglobulin M flare occurred with use of subcutaneous rituximab. Quality of life improved significantly after induction. In total, 48 patients (81%) completed at least six cycles of IRD.

CONCLUSION

Combination of IRD shows promising efficacy with manageable toxicity in patients with relapsed or refractory WM.
Physiological insight into the evolution of complex phenotypes: aerobic performance and the O2 transport pathway of vertebrates
Authors: Scott Graham R. , Dalziel Anne C.
Published: August 2021

Evolutionary physiology strives to understand how the function and integration of physiological systems influence the way in which organisms evolve. Studies of the O2 transport pathway – the integrated physiological system that transports O2 from the environment to mitochondria – are well suited to this endeavour. We consider the mechanistic underpinnings across the O2 pathway for the evolution of aerobic capacity, focusing on studies of artificial selection and naturally selected divergence among wild populations of mammals and fish. We show that evolved changes in aerobic capacity do not require concerted changes across the O2 pathway and can arise quickly from changes in one or a subset of pathway steps. Population divergence in aerobic capacity can be associated with the evolution of plasticity in response to environmental variation or activity. In some cases, initial evolutionary divergence of aerobic capacity arose exclusively from increased capacities for O2 diffusion and/or utilization in active O2-consuming tissues (muscle), which may often constitute first steps in adaptation. However, continued selection leading to greater divergence in aerobic capacity is often associated with increased capacities for circulatory and pulmonary O2 transport. Increases in tissue O2 diffusing capacity may augment the adaptive benefit of increasing circulatory O2 transport owing to their interactive influence on tissue O2 extraction. Theoretical modelling of the O2 pathway suggests that O2 pathway steps with a disproportionately large influence over aerobic capacity have been more likely to evolve, but more work is needed to appreciate the extent to which such physiological principles can predict evolutionary outcomes.
Soft tissue deformations explain most of the mechanical work variations of human walking
Authors: van der Zee Tim J. , Kuo Arthur D.
Published: August 2021

Humans perform mechanical work during walking, some by leg joints actuated by muscles, and some by passive, dissipative soft tissues. Dissipative losses must be restored by active muscle work, potentially in amounts sufficient to cost substantial metabolic energy. The most dissipative, and therefore costly, walking conditions might be predictable from the pendulum-like dynamics of the legs. If this behavior is systematic, it may also predict the work distribution between active joints and passive soft tissues. We therefore tested whether the overall negative work of walking, and the fraction owing to soft tissue dissipation, are both predictable by a simple dynamic walking model across a wide range of conditions. The model predicts whole-body negative work from the leading leg's impact with the ground (termed the collision), to increase with the squared product of walking speed and step length. We experimentally tested this in humans (N=9) walking in 26 different combinations of speed (0.7–2.0 m s−1) and step length (0.5–1.1 m), with recorded motions and ground reaction forces. Whole-body negative collision work increased as predicted (R2=0.73), with a consistent fraction of approximately 63% (R2=0.88) owing to soft tissues. Soft tissue dissipation consistently accounted for approximately 56% of the variation in total whole-body negative work, across a wide range of speed and step length combinations. During typical walking, active work to restore dissipative losses could account for 31% of the net metabolic cost. Soft tissue dissipation, not included in most biomechanical studies, explains most of the variation in negative work of walking, and could account for a substantial fraction of the metabolic cost.
Exploring the growth process of successors in long-lived small and medium-sized manufacturing companies: a qualitative study
Authors: Suzuki Hiroo , Kino Yasunobu
Published: August 2021

Background: Japan is the world's largest country in terms of the number of long-lived companies, the majority of which are family-owned small and medium-sized enterprises. On the other hand, many business owners will be retiring without successors, and the closure of these small and medium enterprises may have a significant impact on the future economy. The purpose of this study is to explore the growth process of successors in long-lived small and medium-sized manufacturing companies so that potential successors can know what they will experience as managers and be prepared for the future, and professionals who support successors can be provided with information on the growth process of successors to provide appropriate support.

Methods: Semi-structured interviews were conducted with six successors of small and medium-sized manufacturing companies that are more than half a century old. Their answers were analyzed using the modified grounded theory approach to construct a hypothetical model.

Results: In total, 46 concepts, four categories, 17 subcategories, and one core category with an analysis result diagram were formed. The diagram shows the successors gained confidence in management through the dilemma between autonomy and constraint in the early stage of succession, which was found in previous research. Following the initial stage, the successors responded to the crisis caused by market constraints such as being stuck in a new market, unreasonable treatment from customers, and created autonomous strategies in their businesses.

Conclusions: By experiencing repetitive crises, the successors tend to acquire new perspectives toward the naturally occurring crises. This change of premise by the successors is considered as the process of double-loop learning. Relationships inside and outside the company influence the generation of this viewpoint. From a long-term perspective, a sense of unity with employees, stable employment, and the pursuit of enjoyment constitute the successors' values in this model.
Empowering young immigrant girls in Canada through the ‘Girls’ Voices’ Curriculum: A qualitative study
Authors: Meherali Salima , Rehmani Mehnaz , Rafiq Arzoo , Punjani Neelam , Vallianatos Helen , Romeu Claudia
Published: August 2021

Background: Gender inequality is a global issue. In Canada, 70% of women experience some form of inequality in their lifetime. Immigrant adolescents in Canada make up a substantial proportion of newcomers, and immigrant girls face the threat of subjugation and oppression, which has a significant impact on their health, development, and economic outcomes as well as gender inequality. Research on girls’ empowerment and resilience-building programs and interventions is virtually nonexistent. In this project, we implemented the ‘Girls’ Voices’ Curriculum. The aim of this project was to engage and empower South Asian (SA) immigrant adolescent girls and to promote gender equality in Canada.

Methods: This study utilized a qualitative descriptive design. Pre- and post-curriculum implementation focus group discussions were conducted.

Results: A total of 16 adolescent girls ranging from 11 to 18 years of age participated in this study. The participants described challenges many young girls face in relation to gender inequality such as gender discrimination, gendered stereotyping, barriers to education, etc. The ‘Girls’ Voices’ Curriculum allowed participants to highlight and reflect on the various problems faced by SA immigrant adolescents in their communities. The participants learned to examine these challenges through a variety of engaging activities to identify their root cause, effects and propose solutions to bring long-lasting change. The curriculum equipped them with useful tools such as decision-makers maps and advocacy skills to educate decision-makers by creating and delivering powerful messages influenced by personal stories and evidence-based literature. 

Conclusion: The study provided significant insight into understanding the diverse challenges encountered by SA immigrant adolescent girls in Canada and linking them to the effectiveness of the ‘Girls’ Voices’ Curriculum. The girl-focused development programs that emphasize developing self-confidence, communication skills, problem-solving skills, and decision making are effective in empowering the socially deprived adolescent girls locally and in the global context.
Cyclic fatigue resistance of four different nickel-titanium instruments in an artificial canal
Authors: Pham Khoa Van
Published: August 2021

Introduction:

The objective of this study was to measure the number of cycles to fracture of four continuous or reciprocating rotary nickel-titanium instruments in different materials.

Methods:

A total of 40 nickel-titanium instruments were used for the present study. Instruments were divided into four groups (n=10): group 1, Revo-S SU; group 2, ProTaper Next X2; group 3, Reciproc R25; group 4, WaveOne Gold Primary. An artificial stainless-steel was used to test the cyclic fatigue of the instruments. The instruments were introduced into the stainless-steel canal, one at a time, until they reached the other end, then they were rotated inside the canal without in-out motion. The time from the beginning of instrument rotation until the occurrence of breakage was recorded. The number of rotated cycles to fracture of the instrument were calculated based on the revolutions per minute (rpm) of each instrument and the recorded rotated time. The mean number of cycles to fracture and standard deviations were calculated and statistically analysed.

Results:

The number of cycles to fracture of the Revo-S SU was the lowest, and that of the WaveOne Gold Primary was highest. Scanning electronic microscope images of fracture surfaces revealed the characteristics of fatigue.

Conclusions:

The number of cycles to fracture of the reciprocating WaveOne Gold Primary system was the highest amongst the tested instruments.
Avulsion injuries: an update on radiologic findings
Authors: Choi Changwon , Lee Sun Joo , Choo Hye Jung , Lee In Sook , Kim Sung Kwan
Published: August 2021

Avulsion injuries result from the application of a tensile force to a musculoskeletal unit or ligament. Although injuries tend to occur more commonly in skeletally immature populations due to the weakness of their apophysis, adults may also be subject to avulsion fractures, particularly those with osteoporotic bones. The most common sites of avulsion injuries in adolescents and children are apophyses of the pelvis and knee. In adults, avulsion injuries commonly occur within the tendon due to underlying degeneration or tendinosis. However, any location can be involved in avulsion injuries. Radiography is the first imaging modality to diagnose avulsion injury, although advanced imaging modalities are occasionally required to identify subtle lesions or to fully delineate the extent of the injury. Ultrasonography has a high spatial resolution with a dynamic assessment potential and allows the comparison of a bone avulsion with the opposite side. Computed tomography is more sensitive for depicting a tiny osseous fragment located adjacent to the expected attachment site of a ligament, tendon, or capsule. Moreover, magnetic resonance imaging is the best imaging modality for the evaluation of soft tissue abnormalities, especially the affected muscles, tendons, and ligaments. Acute avulsion injuries usually manifest as avulsed bone fragments. In contrast, chronic injuries can easily mimic other disease processes, such as infections or neoplasms. Therefore, recognizing the vulnerable sites and characteristic imaging features of avulsion fractures would be helpful in ensuring accurate diagnosis and appropriate patient management. To this end, familiarity with musculoskeletal anatomy and mechanism of injury is necessary.
Back to business
Authors: Barbanel Ben , Rankin Cary , Roberts Liz
Published: August 2021

Despite the ongoing difficulties facing the early years sector, including an increasing number of closures, the UK market has shown a great deal of resilience. Ben Barbanel, head of debt finance at OakNorth Bank, and Cary Rankin, chief executive of Thrive Childcare and Education, joined Nursery World editor in chief, Liz Roberts, for a frank discussion about the business outlook for the early years sector.
‘Lockdown Babies’ in childcare
Authors: Martland Rebecca
Published: August 2021

Babies attending settings for the first time this year would have been born or were very young during the various lockdowns. Rebecca Martland discusses the implications of this through theory and young children's development, offering valuable guidance to implement in your settings, as well as recent case studies to reflect on.
Norland Nanny
Authors: Hart Karen
Published: August 2021

Karen Hart meets Liam Willett, one of the first male degree graduates to qualify as a Norlander. Norland Nannies are famed worldwide for their exceptional training, flexible approach and professionalism.
Deserts
Authors: White Hilary
Published: August 2021

Hilary White discusses how we can explore maths experiences with children, not only through sand play, but also by extending children's wider knowledge of the world, as well as enabling creative freedom.
Web designers
Authors: Harries Judith
Published: August 2021

Explore the wonderful world of spiders and webs with the children in your setting, helping them to better understand these often-maligned creatures and to value the contribution they make to our world.
Making friends
Authors: Hart Karen
Published: August 2021

The communication and language activities here have been designed to encourage conversation and the discovery of new vocabulary while looking at the important subject of friendship.
New term, fresh book corner
Authors: Hewson Claire
Published: August 2021

As well as fostering a love of reading, the book corner is somewhere children build personal, social and emotional skills. Claire Hewson discusses how practitioners can support children's development by giving them ownership and responsibility for a book corner that reflects their interests.
Exploring the Use of South African Ethnic and Racial Slurs on Social Media
Authors: Mbowa Sonia
Published: August 2021

In this paper, I use discourse analysis as a framework to examine Facebook posts and understand how South African ethnic and racial slurs are used and responded to on social media platforms. I illustrate how language in general and slurs in particular work as tools for the negotiation, (re)production, (re)circulation and maintenance of particular ethnic and racial identities and representations. My findings focus on two interrelated aspects of the data: the first concerns the discursive features of the initial posts and the second relates to subsequent responses to the posts. The close examination of initial posts reveals the ways in which the original posters (OPs) position themselves and those they refer to using these slurs. Social media interlocutors recognise the words “kaffir”, “coolie”, “Hottentot” and “makwerekwere” as strongly tied to power and racial/ethnic identity and deliberately use them to provoke controversial debates and to construct “us vs. them” scenarios. The significance of the study is twofold: firstly, it contributes to literature that highlights the role of social media platforms as vehicles for racial and ethnic hate speech. Secondly, it underlines the complexities of race and ethnic relations in the country by highlighting the need for robust discussions around the way South Africans view themselves in comparison to out-group members, including other Africans.
Implementation of a twin-beam state-based clock synchronization system with dispersion-free HOM feedback
Authors: Xie Mengyu , Zhang Haoran , Lin Zaisheng , Long Gui-Lu
Published: August 2021

In the field of clock synchronization, the application of frequency-entangled source is a promising direction to improve accuracy and security. In this paper, we analyze the performance of the twin-beam state and the difference-beam state using a practical second-order interference-based scheme. The advantages of the twin-beam state are pointed out especially for the dispersion-free property of HOM interference in a long-distance clock transfer. With the introduction of dispersion-compensated material, our experimental system based on a twin-beam state achieves a clock accuracy at 4 ps with a time offset precision of 1.8 ps over 10 s acquisition time while the time deviation is 0.15 ps over an averaging time of 5500 s in a 22 km-long transmission. These properties exhibit a leading position compared with the current clock synchronization system using the same theoretical scheme and also competitive among the implementations using other second-order interference-based schemes.
Supercontinuum generated in an all-polarization-maintaining random fiber laser structure
Authors: He Jiuru , Song Rui , Jiang Li , Yang Weiqiang , Hou Jing
Published: August 2021

We demonstrated a linearly-polarized supercontinuum (SC) directly generated in an all-polarization-maintaining random fiber laser (RFL) structure. Owing to the comparatively high Raman gain of the polarization-maintaining germanium doped fiber (GDF), the spectrum of the output SC shows an enhanced bandwidth and improved spectral flatness compared to the unpolarized counterpart. The output SC has an average output power of 4.43 W with a spectrum covering from 600 nm to 1900nm. The polarization extinction ratio (PER) is measured to be greater than 18 dB from 800 nm to 1700nm at the highest output power level. To the best of our knowledge, this is the first demonstration of a linearly-polarized SC generated directly from a RFL. This work is meaningful to help further expand the bandwidth of SC generated from a RFL and provides a simple and cost-effective method of generating linearly-polarized SC for practical applications.
Mueller matrix imaging microscope using dual continuously rotating anisotropic mirrors
Authors: Ruder Alexander , Wright Brandon , Feder Rene , Kilic Ufuk , Hilfiker Matthew , Schubert Eva , Herzinger Craig M. , Schubert Mathias
Published: August 2021

We demonstrate calibration and operation of a Mueller matrix imaging microscope using dual continuously rotating anisotropic mirrors for polarization state generation and analysis. The mirrors contain highly spatially coherent nanostructure slanted columnar titanium thin films deposited onto optically thick titanium layers on quartz substrates. The first mirror acts as polarization state image generator and the second mirror acts as polarization state image detector. The instrument is calibrated using samples consisting of laterally homogeneous properties such as straight-through-air, a clear aperture linear polarizer, and a clear aperture linear retarder waveplate. Mueller matrix images are determined for spatially varying anisotropic samples consisting of a commercially available (Thorlabs) birefringent resolution target and a spatially patterned titanium slanted columnar thin film deposited onto a glass substrate. Calibration and operation are demonstrated at a single wavelength (530 nm) only, while, in principle, the instrument can operate regardless of wavelength. We refer to this imaging ellipsometry configuration as rotating-anisotropic-mirror-sample-rotating-anisotropic-mirror ellipsometry (RAM-S-RAM-E).
Ultrahigh spectral resolution single passband microwave photonic filter
Authors: Wen Hua Shun , Xu Bo Rui , Zhai Kun Peng , Sun Jia Zheng , Wang Jian , Du Xin Hao , Jin Ya , Chen Wei , Li Wei , Zhu Ning Hua , Li Ming
Published: August 2021

Microwave photonic filters (MPFs) with only one ultra-narrow passband are able to provide high frequency selectivity and wide spectral range, and they are of great importance in radio-frequency (RF) signal processing. However, currently all MPFs are limited by trade-offs between key parameters such as spectral resolution and range, tunability, and stability. Here, we report the first demonstration of a single passband MPF with unprecedented performance including ultrahigh spectral resolution of 650 kHz, 0–40 GHz spectral range, and high stability of center frequency drifting within ±50 kHz. This record performance is accomplished by breaking the amplitude equality of a phase-modulated signal via a Brillouin dynamic grating (BDG) which has an ultra-narrow reflection spectrum of sub-MHz. The results point to new ways of creating high performance microwave photonic systems, such as satellite and mobile communications, radars, and remote-sensing systems.
Four dimensional second-order topological insulator based on a synthetic plasmonic metasurface
Authors: Wei Guochao , Liu Zhenzhen , Wu Huizhou , Xiao Junjun
Published: August 2021

It is possible to explore higher dimensional topological properties in lower dimensional structures by introducing additional synthetic dimensions. In this Letter, we construct a four-dimensional (4D) second-order topological insulator using gradient nanoparticle arrays arranged in a periodic lattice. The nanoparticle array has spatially varying inter-particle distance along

x

and

y

directions, which can be regarded as two synthetic dimensions. Different from higher-order topological insulators in classical wave systems, the higher-order topological states in this 4D system are protected by a pair of first Chern numbers in two-dimensional (2D) subspaces instead of by the quantized 2D Zak phases. It is shown that there exist (4-1)- and (4-2)-dimensional boundary states for both transverse and longitudinal collective resonant modes, which provides new, to the best of our knowledge, mechanisms for light confinement and control in such a plasmonic superlattice.
Personenmerkmale und Kommissionierleistungen bei Verwendung eines Pick-by-Watch-Assistenzsystems oder herkömmlicher Papierlisten
Authors: Gerpott Torsten J. , Kurt Ahmet
Published: August 2021

In der Kommissionierung werden anstelle von Papierlisten (Pick-by-Paper) zunehmend digitale Assistenzsysteme (AS) eingesetzt. Hierzu gehören vernetzte Armbanduhren zur Weitergabe von Auftragsdaten an das Personal während es sich im Lager bewegt, um Produkte zu entnehmen (Pick-by-Watch [PbW]). Bislang hat die Forschung sich auf die ergonomische und technische Gestaltung von PbW-Systemen sowie ihre Leistung relativ zu anderen AS konzentriert. Kaum analysiert wurde, ob individuelle Merkmale von Kommissionierern (z. B. Alter) systematische Zusammenhänge mit Leistungsaspekten von AS aufweisen und solche Assoziationen bei verschiedenen AS voneinander abweichen. Ziel der vorliegenden Studie ist es deshalb, Korrelationen zwischen individuellen Merkmalen von Kommissionierern einerseits und Kommissionierleistungskriterien andererseits bei Verwendung eines PbW-Systems oder herkömmlicher Papierlisten empirisch zu bestimmen. Hierzu wurde ein Laborexperiment mit 55 Teilnehmern durchgeführt, für die fünf Dimensionen von Kommissionierleistungen jeweils für ein PbW-AS sowie Papierlisten und fünf personenbezogene Merkmale gemessen wurden. Die empirischen Befunde erweitern den Kenntnisstand zu Spielräumen und Grenzen der Leistungsbeeinflussung in der Kommissionierung durch Einarbeitungs- und Auswahlmaßnahmen, die auf soziodemographische und tätigkeitsbezogene Erfahrungsmerkmale der Aufgabenträger Bezug nehmen.
Requirements Engineering zur Umsetzung des OZG: Status quo, Fallstudie und Optimierungspotenziale zur Realisierung kommunalrelevanter OZG-Lösungen
Authors: Hogrebe Frank
Published: August 2021

Das Gesetz zur Verbesserung des Onlinezugangs zu Verwaltungsleistungen (kurz: Onlinezugangsgesetz – OZG) aus dem Jahr 2017 fordert, dass öffentliche Verwaltungen ihre Verwaltungsleistungen bis Ende 2022 auch elektronisch zugänglich machen. Zur Umsetzung dieser gesetzlichen Forderung bilden adressatenspezifische Anforderungen wesentliche lösungsrelevante Grundlagen. Bund, Länder und Kommunen haben sich zur Umsetzung des OZG auf unterschiedliche Wege gemacht, wobei den Bundesländern mit ihren Kommunen, aufgrund des Umfangs an Verwaltungsleistungen hier eine Schlüsselrolle in Deutschland zukommt. Der Beitrag arbeitet heraus, welcher Rahmen für die Bundesländer bei der OZG-Umsetzung gilt und inwiefern adressatenspezifische Anforderungen dabei zu berücksichtigen sind. Auf Basis von Vergleichsergebnissen eines großen kommunalen IT-Zweckverbandes wird gezeigt, welche Optimierungspotenziale gehoben werden können, sofern adressatenspezifische Anforderungen bereits bei der Umsetzungskonzeption einbezogen werden. Abschließend werden Handlungsempfehlungen aufgezeigt, wie gewählte Umsetzungswege in den Bundesländern mit ihren Kommunen optimiert werden könnten. Der Beitrag adressiert sowohl Führungskräfte und OZG-Leitungskräfte in der Verwaltungspraxis als auch die wissenschaftliche Community in diesem hoch dynamischen Forschungsfeld.