bluuebunny/crossref_metadata_2025 huggingface dataset:
The trajectory of COVID-19 pandemic and handwashing adherence: findings from 14 countries
Authors: Szczuka Zofia , Abraham Charles , Baban Adriana , Brooks Sydney , Cipolletta Sabrina , Danso Ebrima , Dombrowski Stephan U. , Gan Yiqun , Gaspar Tania , de Matos Margarida Gaspar , Griva Konstadina , Jongenelis Michelle , Keller Jan , Knoll Nina , Ma Jinjin , Miah Mohammad Abdul Awal , Morgan Karen , Peraud William , Quintard Bruno , Shah Vishna , Schenkel Konstantin , Scholz Urte , Schwarzer Ralf , Siwa Maria , Szymanski Kamil , Taut Diana , Tomaino Silvia C. M. , Vilchinsky Noa , Wolf Hodaya , Luszczynska Aleksandra
Published: October 2021

Background

The COVID-19 pandemic has affected people’s engagement in health behaviors, especially those that protect individuals from SARS-CoV-2 transmission, such as handwashing/sanitizing. This study investigated whether adherence to the World Health Organization’s (WHO) handwashing guidelines (the outcome variable) was associated with the trajectory of the COVID-19 pandemic, as measured by the following 6 indicators: (i) the number of new cases of COVID-19 morbidity/mortality (a country-level mean calculated for the 14 days prior to data collection), (ii) total cases of COVID-19 morbidity/mortality accumulated since the onset of the pandemic, and (iii) changes in recent cases of COVID-19 morbidity/mortality (a difference between country-level COVID-19 morbidity/mortality in the previous 14 days compared to cases recorded 14–28 days earlier).

Methods

The observational study (#NCT04367337) enrolled 6064 adults residing in Australia, Canada, China, France, Gambia, Germany, Israel, Italy, Malaysia, Poland, Portugal, Romania, Singapore, and Switzerland. Data on handwashing adherence across 8 situations (indicated in the WHO guidelines) were collected via an online survey (March–July 2020). Individual-level handwashing data were matched with the date- and country-specific values of the 6 indices of the trajectory of COVID-19 pandemic, obtained from the WHO daily reports.

Results

Multilevel regression models indicated a negative association between both accumulation of the total cases of COVID-19 morbidity (B = −.041, SE = .013, p = .013) and mortality (B = −.036, SE = .014 p = .002) and handwashing. Higher levels of total COVID-related morbidity and mortality were related to lower handwashing adherence. However, increases in recent cases of COVID-19 morbidity (B = .014, SE = .007, p = .035) and mortality (B = .022, SE = .009, p = .015) were associated with higher levels of handwashing adherence. Analyses controlled for participants’ COVID-19-related situation (their exposure to information about handwashing, being a healthcare professional), sociodemographic characteristics (gender, age, marital status), and country-level variables (strictness of containment and health policies, human development index). The models explained 14–20% of the variance in handwashing adherence.

Conclusions

To better explain levels of protective behaviors such as handwashing, future research should account for indicators of the trajectory of the COVID-19 pandemic.

Trial registration

Clinical Trials.Gov, #NCT04367337
The role of structural and process quality of family planning Care in Modern Contraceptive use in Indonesia: a multilevel analysis
Authors: Nurjaeni Nurjaeni , Sawangdee Yothin , Pattaravanich Umaporn , Holumyong Charamporn , Chamratrithirong Aphichat
Published: October 2021

Introduction

Despite contraceptive behaviors are influenced by multiple and multilevel variables, studies on modern contraceptive use in Indonesia has concentrated on single-level and mostly individual and household variables, and less interest has been devoted to multilevel analysis that accounts for community and SDP characteristics that may affect woman’s decision to use modern FP method. This study aimed to assess the role of structural and process quality of family planning care in modern contraceptive use among women in reproductive ages in Indonesia.

Methods

This study analyzed data from the 2016 PMA2020 survey of 10,210 women in 372 enumeration areas in Indonesia. The data were analyzed using categorical principal component analysis and multilevel mixed-effects logistic regression.

Results

The key variables for structural quality were number of contraceptive provided, SDP supports CHWs, available water and electricity, and skilled FP personnel, while the main factors for process quality were privacy of clients and provision of post-abortion service. There were significant differences across communities in how study variables associated with modern FP adoption. The finding shows the evidence of significant roles of structural and process quality FP care in modern contraceptive use. Moreover, women with high autonomy in FP decision, those who had free national/district health insurance, and those living in a community with higher proportion of women visited by CHW, had higher odds of modern contraceptive usage. Yet, women who live in a community with higher mean ideal number of children or greater proportion of women citing personal/husband/religion opposition to FP, had lower odds of modern contraceptive use than their counterparts.

Conclusion

Study findings suggest improvement in structural and process quality of FP care will yield substantial growths in modern contraceptive use. Moreover, FP workers should also address adverse cultural/traditional customs in community and should target communities where the demand for modern FP was degraded by opposing social beliefs and norms. There was significant variation across communities in how individual, household, community, and SDP factors affect modern FP practice, hence, context should be taken into consideration in the development of FP intervention and promotion programs.
Factors affecting Baker cyst volume, with emphasis on cartilage lesion degree and effusion in the young and middle-aged population
Authors: Saylik Murat , Gokkus Kemal , Sahin M. S.
Published: October 2021

Background

The principal aim of this study was to investigate the presence of factors affecting Baker’s cyst volume in young and middle-aged populations.

Methods

Open cyst excision with valve and capsule repair, as well as knee arthroscopy, were used to treat eighty-five patients. The cases were categorized in terms of age, effusion, chondral lesion degree, meniscal tear degree, and Lindgren scores. An ultrasonography (USG) device was used to calculate the cyst volume. The IBM-SPSS 22 program was used for statistical analysis and to assess the relationships between variables using Spearman’s correlation tests.

Results

The degree of chondral lesion was moderately and positively correlated with cyst volume in the total population (correlation coefficient: 0.469; p < 0.05).

The degree of the chondral lesion was moderately and positively correlated with the degree of effusion (correlation coefficient: 0.492; p < 0.005). The cyst volume was weakly and positively correlated with the degree of effusion (correlation coefficient: 0.20; the correlation was at the limits of statistical significance p = 0.07 < 0.08).

Conclusions

This study revealed that an increase in chondral lesion severity increases the amount of effusion and cyst volume.
Socio-protective effects of active case finding on catastrophic costs from tuberculosis in Ho Chi Minh City, Viet Nam: a longitudinal patient cost survey
Authors: Vo Luan Nguyen Quang , Forse Rachel Jeanette , Codlin Andrew James , Dang Ha Minh , Van Truong Vinh , Nguyen Lan Huu , Nguyen Hoa Binh , Nguyen Nhung Viet , Sidney-Annerstedt Kristi , Lonnroth Knut , Squire S Bertel , Caws Maxine , Worrall Eve , de Siqueira-Filha Noemia Teixeira
Published: October 2021

Background

Many tuberculosis (TB) patients incur catastrophic costs. Active case finding (ACF) may have socio-protective properties that could contribute to the WHO End TB Strategy target of zero TB-affected families suffering catastrophic costs, but available evidence remains limited. This study measured catastrophic cost incurrence and socioeconomic impact of an episode of TB and compared those socioeconomic burdens in patients detected by ACF versus passive case finding (PCF).

Methods

This cross-sectional study fielded a longitudinal adaptation of the WHO TB patient cost survey alongside an ACF intervention from March 2018 to March 2019. The study was conducted in six intervention (ACF) districts and six comparison (PCF) districts of Ho Chi Minh City, Viet Nam. Fifty-two TB patients detected through ACF and 46 TB patients in the PCF cohort were surveyed within two weeks of treatment initiation, at the end of the intensive phase of treatment, and after treatment concluded. The survey measured income, direct and indirect costs, and socioeconomic impact based on which we calculated catastrophic cost as the primary outcome. Local currency was converted into US$ using the average exchange rates reported by OANDA for the study period (VNĐ1 = US$0.0000436, 2018–2019). We fitted logistic regressions for comparisons between the ACF and PCF cohorts as the primary exposures and used generalized estimating equations to adjust for autocorrelation.

Results

ACF patients were poorer than PCF patients (multidimensional poverty ratio: 16 % vs. 7 %; p = 0.033), but incurred lower median pre-treatment costs (US$18 vs. US$80; p < 0.001) and lower median total costs (US$279 vs. US$894; p < 0.001). Fewer ACF patients incurred catastrophic costs (15 % vs. 30 %) and had lower odds of catastrophic cost (aOR = 0.17; 95 % CI: [0.05, 0.67]; p = 0.011), especially during the intensive phase (OR = 0.32; 95 % CI: [0.12, 0.90]; p = 0.030). ACF patient experienced less social exclusion (OR = 0.41; 95 % CI: [0.18, 0.91]; p = 0.030), but more often resorted to financial coping mechanisms (OR = 5.12; 95 % CI: [1.73, 15.14]; p = 0.003).

Conclusions

ACF can be effective in reaching vulnerable populations and mitigating the socioeconomic burden of TB, and can contribute to achieving the WHO End TB Strategy goals. Nevertheless, as TB remains a catastrophic life event, social protection efforts must extend beyond ACF.
Response of bread wheat to sulfur and phosphorus fertilizers in the north central Ethiopia
Authors: Assefa Shawl , Haile Wassie , Tena Wondwosen
Published: October 2021

Background

Emerging research evidences since few years back are indicating that sulfur (S) is becoming a limiting nutrient in some Ethiopian soils. However, these evidences are not sufficient to make a solid conclusion that some soils of Ethiopia have became deficient in S. There is also limited information on the interaction effects of S and phosphorus (P) on bread wheat in Ethiopia. Therefore, an experiment was conducted to evaluate the effects of S and P fertilizers; and their interaction on yield components and yield of bread wheat grown at Gerba and Deneba locations, Northern central Ethiopia. A factorial experiment consisting of three levels (0, 15 and 30 kg ha−1) of S and four levels (0, 11, 22 and 44 kg ha−1) of P was laid out in RCB design with three replications.

Results

Results revealed that yield components and yield of wheat were significantly affected by both main and interaction effects of S and P fertilizers in both locations. At Gerba, S applied at 15 and 30 kg ha−1 increased grain yield (GY) of wheat by 32 and 44% over untreated control treatment, respectively. The corresponding increases at Deneba were 29 and 37% over untreated control treatment, respectively. However, significantly higher GY was obtained with treatments involving combined application of S and P than that obtained with single application of S or P. GY gains due to S and P interaction effect ranged from 46–65 to 52–75% over untreated control treatment at Gerba and Deneba, respectively. Optimum GY of wheat was obtained with treatment involving 15 kg S ha−1 + 22 kg P ha−1.

Conclusion

The results of this experiment revealed that application of P and S fertilizer has significantly increased yield component, grain and straw yield of wheat compared to unfertilized control plot, indicating insufficient soil P and S content for optimum production of wheat and this was confirmed by very low soil test values of S in both sites. Combined application of S and P produced significantly higher yield of wheat than that obtained with single application of S or P indicating synergistic interaction between these nutrients. In all cases, optimum grain and straw yield of wheat was obtained with treatment involving at 22 P + 15 S kg ha−1, while a partial budget analysis result revealed that a combination of 22P and 15S kg ha−1 produced the highest MMR (54.9%). Thus this treatment is found to be economically feasible treatment for bread wheat production in study area of the district.
Report on the 19th international symposium on geo-disaster reduction/high-level academic forum on disaster mitigation and integrated risk defense on the Plateau, 12–15 July 2021, Xining, China
Authors: Liu Fenggui , Zhu Guolong , Wang Fawu
Published: October 2021

The joint event of 19th International Symposium on Geo-disaster Reduction (19ISGdR) and High-Level Academic Forum on Disaster Mitigation and Integrated Risk Defense on the Plateau was held on 11–15 July in Xining, Qinghai Province, China, focusing on the theme of “Geological disaster and integrated risk defense”. This event consisted of keynote lectures, invited lectures, and Youth forum, which provided a platform for scientists, industrial professionals and young scholars to share their research progress and exchange novel ideas on geo-disaster reduction in a hybrid way of offline and online. A post-symposium field trip for three days was also conducted in the joint area between Qinghai-Tibet plateau and Loess plateau.
Huntingtin CAG expansion impairs germ layer patterning in synthetic human 2D gastruloids through polarity defects
Authors: Galgoczi Szilvia , Ruzo Albert , Markopoulos Christian , Yoney Anna , Phan-Everson Tien , Li Shu , Haremaki Tomomi , Metzger Jakob J. , Etoc Fred , Brivanlou Ali H.
Published: October 2021

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of the CAG repeats in the huntingtin gene (HTT). Although HD has been shown to have a developmental component, how early during human embryogenesis the HTT-CAG expansion can cause embryonic defects remains unknown. Here, we demonstrate a specific and highly reproducible CAG length-dependent phenotypic signature in a synthetic model for human gastrulation derived from human embryonic stem cells (hESCs). Specifically, we observed a reduction in the extension of the ectodermal compartment that is associated with enhanced activin signaling. Surprisingly, rather than a cell-autonomous effect, tracking the dynamics of TGFβ signaling demonstrated that HTT-CAG expansion perturbs the spatial restriction of activin response. This is due to defects in the apicobasal polarization in the context of the polarized epithelium of the 2D gastruloid, leading to ectopic subcellular localization of TGFβ receptors. This work refines the earliest developmental window for the prodromal phase of HD to the first 2 weeks of human development, as modeled by our 2D gastruloids.
Δ9-Tetrahydrocannabinol inhibits Hedgehog-dependent patterning during development
Authors: Lo Hsiao-Fan , Hong Mingi , Szutorisz Henrietta , Hurd Yasmin L. , Krauss Robert S.
Published: October 2021

Many developmental disorders are thought to arise from an interaction between genetic and environmental risk factors. The Hedgehog (HH) signaling pathway regulates myriad developmental processes, and pathway inhibition is associated with birth defects, including holoprosencephaly (HPE). Cannabinoids are HH pathway inhibitors, but little is known of their effects on HH-dependent processes in mammalian embryos, and their mechanism of action is unclear. We report that the psychoactive cannabinoid Δ9-tetrahydrocannabinol (THC) induces two hallmark HH loss-of-function phenotypes (HPE and ventral neural tube patterning defects) in Cdon mutant mice, which have a subthreshold deficit in HH signaling. THC therefore acts as a ‘conditional teratogen’, dependent on a complementary but insufficient genetic insult. In vitro findings indicate that THC is a direct inhibitor of the essential HH signal transducer smoothened. The canonical THC receptor, cannabinoid receptor-type 1, is not required for THC to inhibit HH signaling. Cannabis consumption during pregnancy may contribute to a combination of risk factors underlying specific developmental disorders. These findings therefore have significant public health relevance.
Avaliação do conhecimento e do autocuidado de pacientes diabéticos portadores de doenças infecciosas
Authors: Rocha Katia Regina Oliveira Azevedo , Guaraldo Lusiele , Brito Patrícia Dias
Published: October 2021

Objetivo: avaliar o conhecimento e autocuidado dos pacientes diabéticos portadores de doenças infecciosas. Métodos: foi realizado estudo seccional com uma amostra de conveniência de pacientes, em uma unidade de saúde no Rio de Janeiro, com aplicação dos questionários Diabetes Knowledge Scale Questionnaire, Summary of Diabetes Self Care Activities Questionnaire e da Escala Brasileira de Insegurança Alimentar versão reduzida. O estudo foi aprovado pelo Comitê de Ética da Instituição, e todos os pacientes assinaram o Termo de Consentimento Livre e Esclarecido. Resultados: foram incluídos 50 participantes, com idade média de 60,8 ± 10,0 anos, sendo a maioria (60%) do gênero feminino, da cor da pele não branca (64%) com diagnóstico de HIV/AIDS (44%) ou doença de Chagas (38%). Metade da amostra apresentou conhecimento suficiente acerca do diabetes, e a pontuação média foi de 8,02. A média de adesão ao autocuidado foi de 4,9 dias, e a situação de insegurança alimentar foi evidenciada em 62% dos pacientes. Conclusão: neste estudo, foram evidenciados um conhecimento limítrofe, uma baixa adesão às atitudes de autocuidado e uma alta prevalência de segurança alimentar, mostrando a importância de inclusão de aspectos socioeconômicos e psicoemocionais no planejamento de ações educativas interdisciplinares para gestão do diabetes.
Διερεύνηση του ρόλου των ρυθμιστικών μορίων της οδού των ορμονικών υποδοχέων RIP140 και LCoR σε καρκινώματα ενδομητρίου
Authors: Φλίνδρης Στέφανος
Published: October 2021

Εισαγωγή: Ο στόχος της μελέτης ήταν να αναλύσει την έκφραση της πρωτεΐνης που αλληλεπιδρά με τους πυρηνικούς υποδοχείς 1 (RIP140) και του παρτενέρ του τον εξαρτώμενο από προσδέτη συγκαταστολέα πυρηνικών υποδοχέων (LCoR) στον ενδομητριοειδή καρκίνο του ενδομητρίου και να διερευνήσει τη σχέση τους με τον υποδοχέα οιστρογόνου (ER) , τον υποδοχέα προγεστερόνης (PR), το δείκτη Ki-67, τις κλινικοπαθολογοανατομικές παραμέτρους και την επιβίωση των ασθενών.Υλικά και μέθοδοι: Πραγματοποιήθηκε ανοσοϊστοχημική μελέτη για τη διερεύνηση της υποκυτταρικής έκφρασης των RIP140 και LCoR σε δείγματα ενδομητριοειδών καρκίνων του ενδομητρίου. Χρησιμοποιήθηκε στατιστική ανάλυση για τον προσδιορισμό των συσχετίσεων της έκφρασης RIP140 και LCoR με τις κλινικοπαθολογοανατομικές μεταβλητές και για την εκτίμηση των ποσοστών επιβίωσης. Αποτελέσματα: Οι ιστοί του καρκίνου του ενδομητρίου εμφάνισαν υψηλότερη έκφραση RIP140 και LCoR σε σύγκριση με τους γειτονικούς φυσιολογικούς ιστούς. Η έκφραση του κυτταροπλασματικού LCoR συσχετίστηκε θετικά με την έκφραση ER και PR, ενώ η έκφραση του κυτταροπλασματικού RIP140 συσχετίστηκε θετικά με την έκφραση ER. Επιπλέον, η πυρηνική έκφραση του RIP140 συσχετίστηκε θετικά με το Ki-67. Συμπέρασμα: Η μελέτη μας έδειξε ότι η υψηλή κυτταροπλασματική έκφραση του LCOR μπορεί να προβλέψει μεγαλύτερη συνολική επιβίωση ασθενών με ενδομητριοειδές καρκίνο του ενδομητρίου. Ασθενείς με όγκους που εκφράζουν χαμηλά επίπεδα κυτταροπλασματικού LCoR παρουσίασαν χειρότερη επιβίωση σε σύγκριση με εκείνους που εκφράζουν υψηλά επίπεδα.
Self-Effectiveness of Students in the Conditions of Digitalization of Education
Authors: Gireeva M.
Published: October 2021

The article deals with the problem of the formation of self-efficacy of students of professions associated with the risk of decision-making. Self-efficacy implies the ability of a person to cope with specific and complex situations, including emergencies, and to influence the effectiveness of activities and functioning [1]. Therefore, it was decided to take an increase in the level of professional self-efficacy as the basis for solving the problems of the negative impact of the "human factor" on professional activity in conditions of a high level of risk. High self-efficacy it allows not only to take up decisions and cope with complex professional tasks, but also with various stressful situations [16], as well as to avoid risks to their own health, which is of particular importance for employees of professions associated with the risk of.
Humanistic Values of Autistic Communities: on the Material of Research in the Krasnoyarsk Region
Authors: Viktoruk Elena , Mineev V. , Goh A.
Published: October 2021

Today we can say with confidence that in the changing world and in the Russian society, the tasks of transmitting and maintaining material and intangible values of both traditional and innovative cultures are becoming vital. One of the social groups that are in search of their cultural identity and actively forming special, sometimes unique, traditions, norms, rituals, taboos, holidays, symbolism, language are communities of autistics and people-around-autism. This determines the relevance of studying autistic communities as research spaces for identifying patterns and mechanisms for the formation of new cultures, their axiological and ethical-moral components, identifying ways of social reproduction of society and the individual. The hypothesis of the study is that autistic communities are a new cultural phenomenon, not only ensuring the integration of autistic people into society, but also humanizing modern culture. Methods. The research is based on a holistic set of principles and methods of cultural studies, as well as on the methodology of humanitarian and interdisciplinary research. The theoretical and methodological foundations of cultural research were philosophical phenomenology, cultural anthropology, axiological approach, structural and functional analysis and understanding sociology. The leading role was played by the traditional typological, comparative, hermeneutic, phenomenological methods for the humanities. The peculiarity of the study of the autistic community dictates the need to apply methods of qualitative research. Quantitative methods, especially the method of large numbers, in the study of this social group are applicable on a limited scale. Theoretical works and applied developments of scientists of the Department of Philosophy, Sociology and Religious Studies of the Krasnoyarsk State Pedagogical University named after V.P. Astafiev were used. Results. The undertaken study of autistic culture made it possible to reveal its role in the formation of humanistic values of modern society. The hypothesis that autistic communities are a new cultural phenomenon, not only ensuring the integration of autistic people into society, but also humanizing modern culture, has been confirmed.
Muscidae e Calliphoridae (Diptera, Brachycera) associados à decomposição cadavérica no noroeste do Paraná
Authors: Pereira Ana Caroline Oliveira , De Souza Alex Sandro Barros , Gomes Patricia Pereira
Published: October 2021

O presente trabalho teve como objetivo listar quais são os dípteros necrófagos na região noroeste do Paraná. As informações fazem parte de um projeto, aprovado no comitê de ética em pesquisa de animais, em desenvolvimento no IFPR Campus Umuarama. Durante o estudo, um cadáver de suíno com o peso aproximado de 10 kg foi utilizado como substrato, o qual foi colocado em uma gaiola com uma tela, para impedir a entrada de vertebrados necrófagos. A coleta dos insetos foi realizada por meio de uma armadilha modificada. A gaiola de metal que continha o substrato estava fixada no terreno do IFPR Campus Umuarama. Em relação aos insetos foram coletadas cinco espécies de Muscidae (Sarcopromusca pruna; Musca domestica; Hydrotaea aenescens; Sythesiomyia nudiseta e Stomoxys calcitrans) e seis espécies de Calliphoridae (Cochliomyia macellaria; Chrysomya albiceps; Chrysomya megacephala; Lucilia eximia; Lucilia cuprina e Hemilucilia segmentaria). Os espécimes de Stomoxys calcitrans podem ter sido coletados devido à presença de gado de corte próximo ao local. O processo de decomposição se completou em seis dias, o que pode ser devido aos altos índices de temperatura e baixos índices de umidade observados no local. Nesse período foram observados quatro estágios: fresco; enfisematoso; coliquativo e esqueletização. Estes dados são importantes para a construção de um banco de dados de espécies de importância forense.
The Time Variation in Risk Appetite and Uncertainty
Authors: Bekaert Geert , Engstrom Eric C. , Xu Nancy R.
Published: October 2021

We formulate a dynamic no-arbitrage asset pricing model for equities and corporate bonds, featuring time variation in both risk aversion and economic uncertainty. The joint dynamics among cash flows, macroeconomic fundamentals, and risk aversion accommodate both heteroskedasticity and non-Gaussianity. The model delivers measures of risk aversion and uncertainty at the daily frequency. We verify that equity variance risk premiums are very informative about risk aversion, whereas credit spreads and corporate bond volatility are highly correlated with economic uncertainty. Our model-implied risk premiums outperform standard instruments for predicting asset excess returns. Risk aversion is substantially correlated with consumer confidence measures and in early 2020 reacted more strongly to new COVID cases than did an uncertainty proxy.

This paper was accepted by Haoxiang Zhu, finance.
When to Be Agile: Ratings and Version Updates in Mobile Apps
Authors: Allon Gad , Askalidis Georgios , Berry Randall , Immorlica Nicole , Moon Ken , Singh Amandeep
Published: October 2021

Lean and agile models of product development organize the flexible capacity to rapidly update individual products in response to customer feedback. Although agile operations have been adopted across numerous industries, neither the benefits nor the factors explaining when firms choose to become agile are validated and understood. We study these questions using data on the development of mobile apps, which occurs through the dynamic release of new versions into the mobile app marketplace, and the apps’ customer ratings. We develop a structural model estimating the dependence of product versioning on (a) market feedback in the form of customer ratings against (b) project and work-based considerations, such as development timelines, scale economies, and operational constraints. In contrast to when they actually benefit from operational agility, firms become agile when launching riskier products (in terms of uncertainty in initial customer reception) and less agile when they are able to exploit scale economies from coordinating development over a portfolio of apps. Agile operations increase firm payoffs by margins of 20% to 80%, and interestingly, partial agility is often sufficient to capture the bulk of these returns. Finally, turning to a question of marketplace design, we study how the mobile app marketplace should design the display of ratings to incentivize quality (increasing app categories’ average user satisfaction rates by as much as 22%).

This paper was accepted by Jayashankar Swaminathan, operations management.
Effect of Cooperative Learning on Chemistry Students’ Achievement in Rwandan Day-upper Secondary Schools
Authors: Sibomana Aimable , Karegeya Claude , Sentongo John
Published: October 2021

The cooperative learning (CL) is an advanced instructional approach that uses different motivational procedures to make instruction significant and learners more responsible. This study aimed to investigate the effects of cooperative learning on students' achievement in chemistry among the advanced level in 12-year basic education schools; it engaged a quasi-experimental design with one treatment group and a comparison group (control); the first applied cooperative learning in teaching organic chemistry while in the control group, organic chemistry was taught by the conventional teaching methods (CTM). A sample of 257 students participated in the study. The data collected used an organic Chemistry Achievement Test, and its data were analyzed using SPSS version 23.0 and MS Excel 2016. The ANCOVA results showed that learners taught using cooperative learning achieved better than their counterparts in the control group (F=78.07, df=1, 256, p<.001) with the learning gains of 16.0% in traditional methods and 53.6% of cooperative learning approach, respectively. However, there was no statistically significant difference in gender of students. It is recommended that chemistry teachers be trained on cooperative learning and encouraged to apply it in their teaching methods to enhance students' academic achievement.
Application of the Delphi Technique to Determine the Technological Competencies of a Faculty Member
Authors: Sosnytskyi Yurii O. , Sikorskyi Petro I. , Bezborodykh Svitlana M. , Morozova Mariia M. , Moroz Volodymyr P.
Published: October 2021

The formed primary level and dynamic and sustainable development of technological competence provides quality management of teaching activities, increases the efficiency of the educational process, accelerates the achievement of pedagogical goals. Delphi expert assessment technique is increasingly used in the paradigm of pedagogy. Due to the set of advantages and objectivity of assessments, it has become the dominant method of this study. The objective of the study is to determine the current level of manifestation of technological competencies, as well as generalized prospects for development and improvement of the identified level within the selected group of freelance teachers using the technology of independent expert assessments –the Delphi method. In general, the following methods were used in the current study: methods of data collection and coordination, anonymous brainstorming, Delphi expert assessment technique, statistical and mathematical processing of results through Delphi formulas, comparative method, generalisations. The diversified approach to the interpretation of the technological competence of faculty members allowed determining: a) the level of faculty members’ knowledge of modern educational technologies at 89.1%; b) activity-practical aspect of training at 83.0%; c) dissonance between the theoretical and empirical level of teacher training and the algorithm for fulfilling the potential in practice at 21.5%; d) mastery of individual creative technologies for the organisation of an effective educational process at 55.9%; e) forecasted development of technological competencies of faculty members in the 5-year perspective under the condition of application of special control and skill trainings at 50.7%. Conclusion of the study is that according to the arithmetic mean of experts’ assessments of differentiated levels of technological competence, the overall level was 75.1%. The average result of the initial student survey on the estimating of the teachers’ technological competence was 69.7%. The difference of 5.4% between the data allows stating that both methods were relevant in this particular case.
The Indonesian Version of the Physics Metacognition Inventory: Confirmatory Factor Analysis and Rasch Model
Authors: Sukarelawan Moh. Irma , Jumadi Jumadi , Kuswanto Heru , Thohir M. Anas
Published: October 2021

Metacognition inventory supports increased awareness and self-control to improve student’s academic success, including physics. However, there are limitations to revealing the Physics Metacognition Inventory (PMI), especially in Indonesia. This study aims to explore and evaluate the psychometric properties of PMI. This survey research has involved 479 students from three high schools in Indonesia. The psychometric properties of the I-PMI were evaluated using a Confirmatory Factor Analysis and Rasch Model approach. The results show that the Indonesian Physics Metacognition Inventory (I-PMI) is collected in 6 constructs from 26 items. The validity, reliability, and compatibility tests have also been analyzed with good results. The five rating scales used have adequate functionality. This research has also presented more comprehensive information about the Physics Metacognition Inventory in the context of Indonesian culture. This study has implications for using I-PMI to assess students’ metacognition at the high school level in Indonesia and recommendations for future research.
Laser linewidths: tutorial
Authors: McKinstrie C. J. , Stirling T. J. , Helmy A. S.
Published: October 2021

In this tutorial, the physical origins and mathematical analyses of laser linewidths are reviewed. The semi-classical model is based on an equation for the light-mode amplitude that includes random source terms, one term for each process that affects the amplitude (stimulated and spontaneous emission, stimulated absorption, and facet and material loss). Although the source terms are classical, their assigned strengths are consistent with the laws of quantum optics. Analysis of this equation shows that the laser linewidth is proportional to the sum of the (positive) source strengths for all gain and loss processes. Three-level and semiconductor lasers have broader linewidths than comparable four-level lasers, because stimulated absorption and the stimulated emission that compensates it both contribute to the linewidth.
Optical properties of water-coated sea salt model particles
Authors: Kanngießer Franz , Kahnert Michael
Published: October 2021

We investigate the optical properties of marine aerosol in dependence of the water content. To this end we develop a model geometry that realistically mimics the morphological changes as the salt particles take up more water. The results are compared to morphologically simpler models, namely, homogeneous and inhomogeneous superellipsoids, as well as cube-sphere hybrids. The reference model yields depolarization ratios, depending on size and water uptake, in the range from 0 to 0.36 ± 0.12. Overall, the simple models can reproduce optical properties of the reference model. The overall nonsphericity, as well as inhomogeneity are identified as key morphological parameter, while rounding of edges only has a minor impact on optical properties.
Laser frequency noise in next generation gravitational-wave detectors
Authors: Cahillane Craig , Mansell Georgia L. , Sigg Daniel
Published: October 2021

Future ground-based gravitational-wave detectors are slated to detect black hole and neutron star collisions from the entire stellar history of the universe. To achieve the designed detector sensitivities, frequency noise from the laser source must be reduced below the level achieved in current Advanced LIGO detectors. This paper reviews the laser frequency noise suppression scheme in Advanced LIGO, and quantifies the noise coupling to the gravitational-wave readout. The laser frequency noise incident on the current Advanced LIGO detectors is

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at 1~kHz. Future detectors will require even lower incident frequency noise levels to ensure this technical noise source does not limit sensitivity. The frequency noise requirement for a gravitational wave detector with arm lengths of 40~km is estimated to be

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. To reach this goal a new frequency noise suppression scheme is proposed, utilizing two input mode cleaner cavities, and the limits of this scheme are explored. Using this scheme the frequency noise requirement is met, even in pessimistic noise coupling scenarios.
High-performance broadband position-sensitive detector based on lateral photovoltaic effect of PbSe heterostructure
Authors: Ma Jikui , Chen Mingjing , Qiao Shuang , Fu Guangsheng , Wang Shufang
Published: October 2021

PbSe has attracted considerable attention due to its promising applications in optoelectronics and energy harvesting. In this work, we explore the lateral photovoltaic effect (LPE) of PbSe films with a simple PbSe/Si heterostructure under nonuniform light illumination and zero-bias conditions. The LPE response is strongly dependent on the thickness of the PbSe film, but always shows a linear dependence on the laser spot position in an ultra-large working size of 5 mm and exhibits a wide photoresponse ranging from visible to near-infrared. The maximum position sensitivity can reach up to 190 mV/mm for the 15-nm-thick PbSe device at 1064 nm and nonlinearity is less than 4%, demonstrating its new potential application in novel position sensitive detectors (PSDs). Besides, the device also shows an ultrafast response speed, with the rise and fall time of ∼40 µs and ∼105 µs, respectively, and excellent reproducibility. These results bring great inspirations for developing high-performance broadband and self-powered PSDs based on the PbSe/Si heterostructure.
Full-vectorial meshless finite cloud method for an anisotropic optical waveguide analysis
Authors: Wu Xiaoer , Xiao Jinbiao
Published: October 2021

By using the meshless finite cloud method, an efficient full-vectorial mode solver based on the transverse-magnetic-field components is developed to analyze the optical waveguides made of anisotropic materials, in which the waveguide cross-section enclosed by the perfectly matched layers is divided into an appropriate number of homogeneous clouds. The point collocation technique is utilized to create a scattered set of nodes over the cloud, and then the continuity conditions of the longitudinal field components are imposed to appropriately deal with the discrete nodes at the interfaces shared by the adjacent clouds. In comparison with conventional mesh-based numerical techniques, the distributions of solution nodes of the present method can be applied to the area of complexity in a completely free manner. Moreover, an interior nodal distribution adaptively updating along the propagation direction is adopted to accomplish higher computational efficiency while improving numerical accuracy. To validate the proposed method, an anisotropic square waveguide, a magneto-optical raised strip waveguide, and a nematic liquid-crystal channel waveguide are considered as numerical examples, and their modal field distribution and corresponding effective refractive indexes are presented. Results are in good agreement with those published earlier, showing the effectiveness of the present method.
Switchable polarization manipulation at the telecom wavelength based on L-shaped hybrid Au-VO2 nanoholes
Authors: Yang Jing , Zhang Jiasen
Published: October 2021

We propose to achieve switchable polarization manipulation at the telecom wavelength at nanoscale based on L-shaped plasmonic nanoholes in an Au-VO2 film. The L-shaped nanohole acts as a quarter-wave plate or a half-wave plate owing to the phase differences between different plasmon resonant modes, which is controlled by the insulator or metallic phases of VO2. In addition, by changing the structure and removing the bottom Au layer, a switchable full-/quarter-wave plate can be achieved when VO2 transits from the insulating state to the metallic state. Furthermore, we vary the geometrical parameters of the L-shaped hole to tune its resonant spectra and achieve a switchable full-wave plate/polarizer. The multifunctional switchable polarization manipulation abilities together with large bandwidths enable the proposed structures promising applications in nanophotonics and integrated optics.
Optical cooperative effects of multiemitters in a one-dimensional (1D) dense array
Authors: Yoo Sung-Mi
Published: October 2021

We theoretically explore cooperative effects of equally spaced multiemitters in a 1D dense array driven by a low-intensity probe field propagating through a 1D waveguide by modeling the emitters as point-like coupled electric dipoles. We calculate the collective optical spectra of a number of 1D emitter arrays with any radiation-retention coefficient η using both exact classical-electrodynamics and mean-field-theory formalisms. We illustrate cooperative effects of lossless 1D emitter arrays with η = 1 at the emitter spacings, which are displayed by steep edges accompanied by a deep minimum and Fano resonances in the plots of transmissivities as a function of the detuning of the incident light from the emitter resonance. Numerical simulation of the full width of such optical bandgaps reveals that cooperativity between emitters is greater in a small array of size N ≤ 8 than in a larger one of size N > 8. For a lossy 1D emitter array in which the radiation retention coefficient is equal to or less than 0.1 the transmissivity obtained by exact-electrodynamics scheme exhibits no bandgap structures, being in good agreement with the mean-field-theory result. We propose that a 1D multiemitter array may work as a nanoscale filter blocking transmission of light with a frequency in the range of optical bandgaps.
Analysis of non-idealities in rhomb compensators
Authors: Shan Ambalanath , Ramanujam Balaji , Podraza Nikolas J. , Collins Robert W.
Published: October 2021

In-line rotatable rhombs that are only weakly chromatic are desired as compensators for a wide variety of applications in spectroscopic polarimetry and Mueller matrix spectroscopic ellipsometry. These devices employ multiple total internal reflections to generate differences in the phase shifts upon reflection for orthogonal fast and slow axis optical electric field components. A framework has been developed for characterization of non-idealities in the performance of rhombs due to dissipation and associated dichroism upon each reflection as well as stress-induced birefringence along each beam path. External oblique reflection measurements by spectroscopic ellipsometry for the internally reflecting interface structures has enabled characterization of the dichroic effects and retardance generated by the reflections. The framework for analysis of the effects of stress relies on simulations demonstrating that the contributions to polarization modification from each beam path depend only on the accumulated stress-induced retardance and average azimuthal angle of the fast principal stress axis along the given path. The overall approach has been applied to straight-through Mueller matrix measurements of a three-reflection rhomb in its operational configuration to establish the set of stress parameters for each of the four beam paths needed to fit the measurements. Thus, device geometry and optical structure, including layer thicknesses and component media optical properties, as well as stress-induced retardances and average stress azimuthal angles, which are all deduced in the analysis, enable a complete description of the polarization modifying properties of the rhomb when serving as a compensator.
The work of watching Twitch: Audience labour in livestreaming and esports
Authors: Carter Marcus , Egliston Ben
Published: October 2021

This article focuses on the interactivity afforded to audiences by the video game livestreaming platform twitch.tv. Drawing on theories of audience labour, we explore what audience interactivity on Twitch might mean within the context of the contemporary digital economy. Specifically, and inspired by a range of existing work in media and cultural studies research on audiences, we argue that interactive audience practices on Twitch can be read as a site of ‘audience work’. Our contention is that the various kinds of interactive, audience practices on Twitch generate considerable economic value for the platform and its broadcasters. In the context of growing academic interest in livestreaming platforms like Twitch, this article contributes a new perspective towards the role that the interactivity of Twitch plays in creating commodified and commercially desirable experiences via the labour of audience activity.
A class of fourth-order elliptic equations with concave and convex nonlinearities in $\mathbb{R}^N$
Authors: Wu Zijian , Chen Haibo
Published: October 2021

In this article, we study the multiplicity of solutions for a class of fourth-order elliptic equations with concave and convex nonlinearities in $\mathbb{R}^N$. Under the appropriate assumption, we prove that there are at least two solutions for the equation by Nehari manifold and Ekeland variational principle, one of which is the ground state solution.
Percepções de educação freireana no projeto Tarralfas
Authors: Bezerra Heriberto Silva Nunes
Published: October 2021

Este trabalho evidencia a análise da relação entre educador-educando a partir da prática pedagógica do projeto de extensão Tarralfas, da Pró-reitoria de Extensão do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte. Partimos de uma pesquisa qualitativa com a observação participante a uma comunidade de pescadores e donas de casa na Praia de Pirangi do Sul, no Rio Grande do Norte, e da ação dos agentes alfabetizadores. A práxis docente foi analisada à luz das obras de Paulo Freire. Evidenciamos que no processo de apreensão do saber e da cultura, as práticas pedagógicas necessitam conduzir educador e educando à liberdade.
Os saberes e dizeres matemáticos dos alunos da EJA
Authors: Quaresma Leila Carla dos Santos , Santos Reinaldo Batista dos
Published: October 2021

Este artigo discute os saberes e dizeres matemáticos dos alunos da Educação de Jovens e Adultos (EJA), trazendo à tona a importância de sua leitura de mundo. Tomamos como metodologia uma abordagem qualitativa de base interpretativa. O enfoque deste trabalho é discutir sobre a educação popular na modalidade da EJA sob a perspectiva freiriana e analisar o que os alunos da EJA sabem e dizem sobre a Matemática, considerando a prática de leitura de mundo realizada por eles em seu cotidiano, objetivando estabelecer a relação entre o contexto no qual os sujeitos que fazem parte da pesquisa estão inseridos. Fundamentamos com os autores: Freire (1988, 1987), D’Ambrósio (2008), Arroyo (2017), dentre outros. A partir das investigações foi possível perceber que os estudantes da EJA vivenciam, diariamente, um percurso de deslocamentos entre trabalho e escola. Desenvolvem habilidades matemáticas em seu cotidiano e praticam leituras de mundo que podem encontrar sentido e valor para os estudantes quando articuladas com a Matemática escolar. Portanto, são praticantes das operações matemáticas na vida, “da leitura de mundo”, e desejam se apropriar dos saberes matemáticos da escola para agregar aos seus, os quais, sobretudo, são utilitários e precisam ser valorizados no currículo escolar.
Círculo de cultura e Educação Física escolar
Authors: Sousa Claudio Aparecido de
Published: October 2021

O objetivo do presente estudo foi verificar como o Círculo de Cultura, inspirado na visão decolonial de Paulo Freire, está sendo utilizado na prática pedagógica do componente curricular Educação Física. Trata-se de uma estratégia didática e metodológica que foi idealizada inicialmente visando alfabetizar adultos em um contexto de educação popular, aqui concebida na experiência do Brasil. Cabe ressaltar que este estudo se refere a um ensaio teórico, iniciado com a leitura de artigos científicos e livros disponíveis na literatura de Educação Física. Concluímos que nossa inspiração na visão decolonial de Paulo Freire permitiu identificar que a área utiliza pouco a proposta do Círculo de Cultura, seja como tratativa de intervenção ou de organização prática. Assim, os cinco artigos que trataram sobre Círculo de Cultura não utilizaram o conceito decolonial de Freire nos textos, no entanto houve explanação nos trabalhos sobre os conceitos freireanos de diálogo, conscientização e efetiva participação dos estudantes na reinvenção de novas práticas corporais, vivenciados em um contexto de educação popular, demonstrando que o legado de Freire contribui para a organização didática das aulas de Educação Física escolar.