bluuebunny/crossref_metadata_2025 huggingface dataset:
Validierung ausgewählter Tablet-Apps zur Bestimmung der Sehschärfe
Authors: Velmans Rebecca , Savioli Kathi , Dietze Holger
Published: July 2024

Purpose. The aim of the study is to investigate whether applications for mobile devices are suitable for the professional determination of visual acuity. Material and Methods. The best-corrected logMAR was determined in 25 healthy subjects (age: 25.7 ± 6.7; Vcc ≥ 1.0) using the Konan Acuity and the Snellen chart applications with letters (B) and with Landolt rings at 4 orientations (L) both without an additional lens (0) and with additional spherical lenses +0.50 D (0.5) or +1.00 D (1.0), and compared with the logMAR determined on the corresponding ETDRS charts. Furthermore, the best-corrected logMAR was investigated for 6 of the 25 participants on the tablet at three different screen brightnesses (80, 200 and 370 cd/m²). Results. For the Konan Acuity app, the following mean values and significant logMAR differences to the ETDRS charts were determined: B0: −0.20; ∆ = −0.03 (p = 0.045); B0.5: −0.13; ∆ = −0.04; (p < 0.001); B1.0: 0.06; ∆ = −0.08 (p < 0.001); L0: −0.20; ∆ = −0.06 (p < 0.001); L0.5: −0,13; ∆ = −0.09 (p < 0.001); L1.0: 0.08; ∆ = −0.11 (p < 0.001). For the Snellen chart app, the following mean values and significant logMAR differences to the ETDRS charts were determined: B0: −0.22; ∆ = −0.05 (p < 0.001); B0.5: −0.16; ∆ = −0.07 (p < 0.001); B1.0: 0.05; ∆ = −0.09 (p < 0.001); L0: −0.23; ∆ = −0.08 (p < 0.001); L0.5: −0.17; ∆ = −0.12 (p < 0.001); L1.0: 0.08; ∆ = −0.11 (p < 0.001). The median logMAR differences between the different screen brightnesses were 0.02 (80 – 200 cd/m²) and 0.00 (370 – 200 cd/m²). Conclusion. At ideal screen brightness, both applications show significant differences to the ETDRS charts. However, these can be regarded as tolerable in clinical practice, at least in young, healthy eyes. The measurements with deviating screen brightness show only minor differences. With the right app, tablets are suitable for determining visual acuity in everyday clinical practice, but are unsuitable for scientific or expert purposes. Keywords Visual acuity, ETDRS chart, Konan acuity chart, Snellen chart
SAĞLIK HİZMET HATASI ALGISININ İNCELENMESİ: AZERBAYCAN ÖRNEĞİ
Authors: Guliyev Nijat , Bilbay Furkan
Published: July 2024

Amaç: Bu çalışmanın amacı Azerbaycan’da sağlık hizmet hatalarının neler olduğunu incelemektir. Gereç ve Yöntem: Bu çalışmada nicel araştırma yöntemlerinden tarama araştırma yöntemi kullanılmıştır. Çalışmanın evrenini Azerbaycan’da sağlık hizmeti almış 18 yaş üstü bireyler oluşturmaktadır. Veriler anket tekniği ile kolayda örneklem yöntemi kullanılarak toplanmıştır. Toplanan verilere SPSS paket programı kullanılarak frekans analizi uygulanmış ortalamalara bakılmıştır. Bulgular: Katılımcıların %49,8’i erkek, %50,2’si kadın olup, yaş ortalaması 26,87±7,65 yıldır. Katılımcıların %54,7’si sağlık hizmet hataları ile karşılaştığını bildirmiştir. Sağlık hizmet hatalarının en önemli nedenlerinin sırasıyla hizmet sunum hataları, fiziksel alt yapı ile ilgili hatalar, fiyat konusunda yapılan hatalar, hasta şikâyetlerinin üst merciler tarafından ciddiye alınmaması ile ilgili hatalar, mevzuat dışında ücret talep edilmesi ve acil hizmetlerinden ücret talep edilmesi ile ilgili olduğu görülmüştür. Sonuç: Çalışma sonuçları değerlendirildiğinde iş deneyimi, hasta sayısı, vardiyalı çalışma ve sağlık çalışanlarının haklarının devlet tarafından yeterince ödenmemesi, oturmuş bir sağlık sigorta sisteminin olmaması sağlık hizmet hatalarına neden olan önemli konular olduğu söylenebilir. Sağlık çalışanlarının tıbbi bilgilerini geliştirmek için eğitim kursları ve eğitim-öğretim sürecinin değiştirilmesi, bakım verdikleri hasta sayısının azaltılması, çalışma saatlerinin düzenlenmesi ve devlet tarafından sağlık sisteminde çalışanların gelir düzeyinin iyileştirilmesi önerilir.
Fistuloclysis in the nutritional management of a enteroatmospheric fistula: case report and literature review
Authors: Kumaira Fonseca Mariana , Neiva Baldissera  , Rizental Laís Borges , Sarmento Pedro Adolfo de Andrade , Cunha Carlos Eduardo Bastian da , Leonardi Luiza , Siebert Júnior Mauro de Souza , Franco Filho João Wilney
Published: July 2024

Introduction: The open abdomen (OA) strategy has been widely adopted as a life-saving intervention in critically ill patients. Initially described as part of the damage control surgery in trauma practice, OA techniques have since further expanded its indications, being successfully adapted to many non-trauma emergent surgical conditions, including abdominal compartment syndrome, severe acute pancreatitis, vascular diseases, and peritonitis/intra-abdominal sepsis. Case Report: This report presents a successful application of this technique in the management of a high-output enteroatmospheric fistula following abdominal complications in a trauma patient. Final considerations: Fistuloclysis is a promising modality for the nutritional support of complex cases of enteroatmospheric fistula in OA patients that also align with the recent efforts to ensure enteral nutrition whenever feasible. Besides its advantages over prolonged exclusive parenteral nutrition in terms of morbidity and costs, the improvement in bowel mucosal trophism is critical for the definitive reconstructive surgery. Future clinical guidelines may encourage the use of fistuloclysis as a safe and effective alternative method for the management of these challenging cases.
Supplementation of lemon juice through drinking water on performance, egg quality, serum biochemical indices and combat heat stress in laying pullets
Authors: Keya Jannatul , Ahammed Musabbir , Ray Bipul , Tanim Lamia , Dey Bapon
Published: July 2024

BACKGROUND: Numerous feed additives, such as probiotics, prebiotics, organic acids, and enzymes, have the potential to optimize weight gain, feed efficiency and maintain the acid-base balance which eventually contributes to improve production performance. The purpose of the current study was to investigate the possible advantages of lemon juice (LJ) on laying performance, egg quality, serum biochemical properties, and layers' ability to recover from heat stress.
METHODOLOGY: Ninety-six Hy-Line Brown layers all 29 weeks were randomly assigned to four treatments, each with six replications, and were given a six-hour daily drinking experiment. The birds were provided with 0% (control), 0.5%, 1% and 1.5% LJ respectively for 6 weeks. The temperature, humidity, hen day egg production (HDEP) and egg weight (EW) were recorded. Egg quality indices were measured bi-weekly. An analysis of total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), blood glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), packed cell volume (PCV), heterophil (H), lymphocyte (L) count, and heterophil-lymphocyte (H/L) ratio was performed on the blood sample collected at the end of the experiment.
KEY FINDINGS: The studied parameters among the various treated groups showed that the egg weight, feed conversion ratio (FCR), egg quality parameters, HDL, TG, AST, heterophil count, lymphocyte count and H/L ratio did not differ significantly (P > 0.05). HDEP, egg mass output (EMO) and FI differed significantly (P < 0.01) compared to the control group. The significant reduction in TC, LDL, glucose, ALT, increase in feed intake, HDEP and PCV showed that LJ had a positive effect in reducing the adverse effects of heat stress in laying pullets.
CONCLUSION: Taken together, it may be concluded that LJ can be used to improve the laying performance and reduce the heat stress in layers.
Transformation of the political elite of Kyrgyzstan (1991-2024): Dynamics and analysis
Authors: Kazak Nurgul , Zhunushova Saikal , Abdymomunova Kulnara , Niiazalieva Kunduz , Asanbaeva Gulzana
Published: July 2024

Relevance. This study is relevant as it analyzes the complex transformation of Kyrgyzstan's political elite since independence, examining critical issues like the impact of revolutions, persistence of clan systems, and challenges to democratization. Purpose. The purpose of the study was to analyse the dynamics and transformation of the political elite of Kyrgyzstan since independence to identify the main trends and factors determining its evolution. Methodology. The research uses mixed methods, including legislative analysis, statistical data review, and content analysis of political speeches. Results. The results revealed that the political elite of Kyrgyzstan as a phenomenon still remains a clan-based, elite-patronage system with elements of corruption and requires a rethink of ineffective behavioural practices that have acquired a cyclical character, undermining the effectiveness of a series of revolutions that have occurred. It was highlighted that the increased number of revolutionary events in the country indicates both the strengthening of national identity and the desire to set the country on the path of democratic development, and the difficulties in forming a new political elite due to various factors. A comparative analysis of events in other Central Asian countries demonstrates similar trends in the establishment of political elites and obstacles in the establishment of democracy. Conclusions. The study concludes that the political elite remains largely based on patronage networks despite regime changes. Revolutionary events have not led to sustainable democratic reforms. Gender representation has improved but falls short of goals. Press freedom faces increasing restrictions. The research suggests that achieving stable democratic governance requires addressing clan politics, corruption, and weak institutions. It emphasizes the need for transparent, merit-based systems in political recruitment. The study highlights the ongoing tension between democratic aspirations and authoritarian practices in Kyrgyzstan's political landscape. Keywords: hybridity; cyclicality; solidarity; security; clan elite selection system; elite patronage system
Uprisings in Kazakhstan Against the Tsarist Government in 1916 and Soviet Policy in 1921-1922. Similarities and Differences (Based on the Materials of Akmola and Atbasar Districts)
Authors: Seytkazina Kuralay , Tussupova Gulden , Sadykov Tlegen , Omarov Daulet , Nabiyev Sayat
Published: July 2024

Relevance. The study of Kazakhstan's national liberation movements in the early XX century, particularly the uprisings against tsarist rule in 1916 and Soviet rule in 1921-1922, is highly relevant for understanding the country's path to independence. Purpose. The research aimed to examine the causes, conditions, and driving forces behind these uprisings in the Akmola and Atbasar districts, as well as identify similarities and differences between them. Methodology. Materials from the archives of the Central State Museum of the Republic of Kazakhstan, the Ministry of Internal Affairs of the Republic of Kazakhstan, the Regional Museum of the Akmola Region, the Regional Museum of the Kostanay Region, the museums of the cities of Astana, Zhezkazgan, Kyzylorda, Arkalyk were used, including information that was used for the first time during the writing of the article. The historical-systemic, historical-comparative, chronological and observational methods were used; as well as historical, historical-social, and other research methods. Results. The study found that both uprisings were driven by oppressive policies, excessive taxation, and land seizures by the ruling powers. Local leaders emerged to organize resistance in both cases. The 1916 uprising was sparked by forced conscription, while the 1921-22 uprising responded to Soviet food requisition policies. Both were violently suppressed by authorities. Conclusions. The researchers conclude that these uprisings were important links in Kazakhstan's centuries-long struggle for independence. They argue for a reassessment of these events and their leaders in Kazakhstan's national history. Keywords: Kazakhstan history; Soviet Government; Tsarism; USSR
Screening Cholinesterase Inhibitory Potential of Selected Amines
Authors: Mavideniz Açelya , Ercetin Tugba , Yektaoglu Aybike , Nobavar Zahra , Yuzugulen Jale , Özyılmaz Emine Dilek , Gülcan Hayrettin Ozan
Published: July 2024

Cholinesterase inhibition has gained attention in the treatment of some disease states, covering cholinergic deficiency. Alzheimer’s disease (AD) can be counted as the most important one among them. Indeed, the current drugs used in the treatment of AD are cholinesterase inhibitor molecules, besides memantine, and biological new drugs. Many pharmacophores have been suggested so far for cholinesterase inhibition and many of them possess a basic center with an amine function. Within this work, we have selected some simple amines and investigated their potential to inhibit acetylcholinesterase and butyrylcholinesterase enzymes. The results indicated that simple amines by themselves don’t have strong potential unless they are used with other pharmacophores.
The Problems of Practice: Bricolage as a Metaphor for Teachers’ Work and Learning
Authors: Scribner Jay Paredes
Published: July 2024

In this article the author uses Levi-Strauss’ (1966) metaphor of Bricolage to examine how teachers, not policymakers, make sense of their “problems of practice” in three United States high schools. The article also examines how teachers address these problems of practice. It concludes by underscoring the disconnect between teachers’ and policymakers’ perspectives on the challenges to teacher practice in the US. Finally, implications for practice and research are drawn.
Freire (with Bakhtin) and the Dialogic Classroom Seminar
Authors: Bowers Rick
Published: July 2024

This article on pedagogy in the classroom seminar combines the basic principles of dialogue and liberation as expressed especially by 20th-century thinkers Bakhtin and Freire. It argues for a pedagogy of educational growth and facilitation of ideas. Through learner-centered knowledge, dialogic interaction, open exploration, mutual respect, and problem-based learning—as opposed to a pedagogy of conflict, including scenarios of confrontation, monologic assertions of instruction, and expert communiqués—the classroom seminar undergoes authentic liberation and discovery. At all points the classroom must be free from coercion and open to alternative perspectives in order to weigh evidence and arguments as objectively as possible, to break patterns of vertical authority, and to involve all participants in their own education. Not usually compared, these Bakhtinian and Freirean procedures provide sustainable, compassionate, and empowering possibilities for the university classroom seminar in North America and elsewhere.
Motivational Influences to Pursue Graduate Studies in Secondary Music Education
Authors: Dust Thomas J.
Published: July 2024

Motivational influences on the decision to pursue graduate studies in secondary music education were investigated. The population of secondary music education graduate students in one large Canadian university (N=13) completed a survey that included both open-ended and closed-ended response items. The greatest motivational influences to pursue graduate studies were found to be: (a) intellectual development, (b) personal development, and (c) professional development. The motivational influence Need to Refresh showed the most diversity and elicited the most prose response. Standard deviations indicated that on most items the response group was homogeneous. All results were consistent across gender and degree program, master’s or doctoral. In contrast to similar studies of educators in general, the influence of Potential Monetary Gain was not identified as important. Demographic information supplied by respondents indicated that the typical secondary music education graduate student in this university was 30 or more years of age and had five to 14 years of teaching experience. Results of this study cannot be generalized beyond the population from which the data were collected.
Leadership for Technology Integration: Computing the Reality
Authors: Leonard Lawrence J. , Leonard Pauline E.
Published: July 2024

United States school districts continue to spend billions of dollars annually on various forms of technology equipment and services. Despite the widespread expectation that teachers routinely integrate technology into the curriculum to facilitate student achievement, there is substantial evidence that this is not occurring either in the manner or to the degree desirable. This study examined the extent to which computer-related technology is used in 12 school districts in North Louisiana from the perspectives of 214 site-based administrators in 149 schools. The findings suggest that technology integration remains problematic in that many teachers seem unwilling or unable to incorporate technology into the teaching and learning process. Furthermore, the data reveal that many school administrators consider themselves ill prepared to assume the role of technology leader. The implications of these and other findings for school improvement are discussed.
Educating the Country Out of the Child and Educating the Child Out of the Country: An Excursion in Spectrology
Authors: Corbett Mike
Published: July 2024

A focus on rurality has been largely absent from much contemporary educational policy discussion. At best, rural education is a peripheral concern just as rural areas are increasingly considered marginal to the development of a globalized, networked, fast capitalism. In Canada rural, coastal, northern, and single-industry communities that were built around primary resource extraction are constructed as social and educational problem spaces partly because their residents are often attached to these places long after they have served their economic purpose as natural resource deposits for the interests of capital. In fact rurality and rusticity are typically seen as one face of the kind of localized social condition that formal education is designed to normalize and transform by fostering outmigration and a general orientation to urban life and to mobility. In this analysis I use Derrida’s idea of spectrology to examine some images of rurality as persistent, place-attached ghosts haunting the educational project of modernity.
Gender Differences in Cooperative Learning with University Students
Authors: Rodger Susan , Murray Harry G. , Cummings Anne L.
Published: July 2024

Differences in achievement were investigated for 80 female and 80 male university students who were randomly assigned to either cooperative or competitive teaching methods. After viewing a videotaped instruction on research design, participants completed a mini-assignment either individually in the competitive condition or with a same-sex partner in the cooperative condition. All participants individually completed a multiple-choice test to assess achievement. Although no differences were found on the multiple-choice test, on the mini-assignment women scored significantly higher in the cooperative than in the competitive condition, whereas men performed about equally in both conditions.
Action Research: A Spiral Inquiry for Valid and Useful Knowledge
Authors: Moghaddam Alireza
Published: July 2024

This article discusses methodological and philosophical issues linked to action research. The concepts of subjectivity and objectivity—potential sources of bias that mislead researchers in dealing with these concepts—and how to cope with them are discussed. Controversial issues of truth in positivism, postpositivism, and other schools of philosophy are considered. Finally, the article touches on validity criteria, validity types, and how to grapple with validity in action research.
On Viewing Educational Research as a Textual Enterprise
Authors: Little Joseph
Published: July 2024

This article explores the history of North American educational research in an attempt to offer readers a historically informed view of the field as a whole. The first part of the article situates many of the major research programs in their original social settings, showing how they emerged in response to various administrative and academic pressures. The second part acknowledges the textual underpinnings of educational research by underscoring the practical reality that researchers produce patterned forms of text, which are used in patterned social situations to accomplish anticipated goals.
Exploring Attitudes of Future Educators About Sexual Minority Youth
Authors: Dowling Kristen B. , Rodger Susan , Cummings Anne L.
Published: July 2024

Fifty-two secondary teacher candidates from a Canadian university completed questionnaires assessing levels of homoprejudice, knowledge of homosexuality, and perceptions of professional issues related to sexual minority youth. The level of homoprejudice in this sample was lower than in earlier studies with teachers, and lower homoprejudice was found to be significantly related to higher professional commitment and willingness to assist sexual minority students. As well greater knowledge of homosexual issues was significantly related to lower levels of homoprejudice, and men had significantly more homoprejudiced attitudes than women.
Evaluation of Elementary Students’ Attitudes Toward Science as a Result of the Introduction of an Enriched Science Curriculum
Authors: Nadirova Anna , Burger John
Published: July 2024

One of the challenges facing school educators is motivating students to learn science. This study is part of an evaluation of enriched science curriculum introduced in five western Canadian (Alberta) urban schools. The objective was to develop a multidimensional instrument suitable for evaluating the attitudes of students toward science with a potential to be used for classroom assessments. The study addressed instrument validity and reliability by testing a 40-item questionnaire using data from grade 4 students. The six-factor solution provided a conceptual foundation for future studies and instrument refinement. Overall, students who had been learning the experimental curriculum for three years displayed more positive attitudes toward science than control students.
Circles of Influence: The Role of School-Community Partnerships in the Character Formation and Citizenship of Secondary School Students
Authors: Hands Catherine M.
Published: July 2024

Partnerships between schools, families, and communities provide a support net for each student and play a role in promoting academic success (Epstein, 1995; Shapiro, Ginsberg, & Brown, 2002) and moral development. This article is based on a qualitative study of a secondary school with numerous partnerships selected from a southern Ontario school board characterized by economic and cultural diversity. Drawing on the analysis of archival data, observations, and 19 interviews with the educators and community partners at one of the schools, it was found that the study participants shared an understanding of education as the joint responsibility of the school and the community. This article discusses the partnership practices and in so doing, the roles of community partners in encouraging moral development by supporting students academically, emotionally, and socially. When community partners provided learning opportunities and resources not available in the school, the students enhanced their skill sets and were exposed to diverse community values. Through partnership activities, civic responsibility was promoted, and students’ social capital was strengthened as they established their own links with the community in which they lived.
Between Meaning-Making and Learning the “Rule”: The Case of a Prospective Teacher of Mathematics at the Secondary Level
Authors: Proulx Jérôme
Published: July 2024

This article reports on a case study intended to improve understanding of the development and characteristics of prospective mathematics teachers’ oral explanations. The teaching practices of Donna, who taught algebraic operations, were analyzed, after which she was interviewed. The presence of an important tension in how Donna explained mathematics emerged where her explanations were divided between contextualized understandings and formalized knowledge, highlighting the difficulties in teaching of transition from one to the other. The article concludes with a discussion of a plausible rationale for this tension, which emerges from an understanding of mathematics as reduced to a call for formalized procedures.
The Academic Mobility of Students for Whom English is Not a First Language: The Roles of Ethnicity, Language, and Class
Authors: Garnett Bruce , Adamuti-Trache Maria , Ungerleider Charles
Published: July 2024

This study uses extant data to examine the roles of ethnicity, social class, and linguistic proficiency in predicting the participation and performance of students for whom English is not a first language (ENFL) from the class of 2002 in a provincially examinable grade 12 subject areas in a large urban British Columbia school district (n=4,075). Descriptive statistics show similar performance levels, but variable participation rates among ENFL and native English-speaking (NES) baseline students. However, these results mask differences between ethnolinguistic subgroups of ENFL students. Linear and logistic regressions show that although social class and linguistic proficiency significantly affect outcomes, participation and performance advantages to Chinese- and Korean-speaking students over their ENFL and NES peers hold across the sciences. Smaller performance advantages to Chinese speakers hold across the humanities.
French Immersion Studies: From Second-Language Acquisition (SLA) to Social Issues
Authors: Roy Sylvie
Published: July 2024

French immersion in Canada was instituted by parents in Québec who wished their children to learn French in order to have social, political, and economic advantages. Several learning theories and research methods, especially those related to second-language acquisition (SLA), have been used in the field of French immersion. More recently, sociocultural, critical, and sociolinguistic theories are informing the field of French immersion. Suggestions for future research include examining how to apply theory to practice, providing new pedagogical approaches, reexamining the relevance of programs to the current clientele, and rethinking bilingualism and multiculturalism in Canada.
Awareness, Discovery, Becoming, and Debriefing: Promoting Cross-Cultural Pedagogical Understanding in an Undergraduate Education Program
Authors: Johnston Ingrid , Carson Terry , Richardson George , Donald Dwayne , Plews John , Kim Mijung
Published: July 2024

This article discusses the first phase of an action research project aimed at identifying a collaborative and collective response to the need to prepare student teachers to work in diverse school contexts. The research brought together university researchers, community and cultural institutions, professional associations, school boards, and government and civil organizations to design a Diversity Institute for integration into the teacher preparation program at the University of Alberta. Student teachers’ responses to the Diversity Institute suggest that although a few participants were able to develop new understandings of themselves and others and to effect changes in their pedagogical practices, many remained at a shallow level of awareness about the complexities of diversity and difference. Reflections on the first phase of the Institute point to the underlying dynamics of learning and unlearning that are at work in becoming a teacher and the need for time and space for a deeper engagement with diversity in the teacher education program.
Peer Observation Reports and Student Evaluations of Teaching: Who Are the Experts?
Authors: Ackerman David , Gross Barbara L. , Vigneron Franck
Published: July 2024

This study is an exploratory inquiry into the perceptions of university faculty regarding two forms of teaching evaluations, student evaluations of teaching (SET), and peer observation reports (POR). Which, if either, better assesses the quality of instruction? Who are the real experts in judging teaching quality: peers who are experts in their field or students who are the recipients of instruction? Results suggest that it is better not to rely on a single source of information as evidence of teaching effectiveness. SET and POR provide complementary information from differing perspectives. Advantages and disadvantages of both are discussed.
Is Recess an Achievement Context? An Application of Expectancy-Value Theory to Playground Choices
Authors: Spencer-Cavaliere Nancy , Dunn Janice Causgrove , Watkinson E. Jane
Published: July 2024

This study investigated the application of an expectancy-value model to children’s activity choices on the playground at recess. The purpose was to test the prediction that expectancies for success and subjective task values are related to decisions to engage in specific recess activities such as climbing, playing soccer, or skipping rope. Participants included 242 children in grades 1-4 from five schools. Participation in playground activities was assessed using the Activities for Daily Living in Physical Play (ADL-PP) (Watkinson et al., 2001). Task-specific expectancies and values were measured on the playground activities contained in the ADL-PP. The results indicated that children’s perceptions of competence were significantly higher on playground skills that they had identified as most important compared with least important (p
Age and Task-Related Effects on Young Children’s Understanding of a Complex Picture Story
Authors: Hayward Denyse , Schneider Phyllis , Gillam Ronald B.
Published: July 2024

In this study we examined age- and task-related effects in story schema knowledge across an independent narrative task (story formulations) and a supported narrative task (answering questions). We also examined age-related changes to questions about the story as a whole. Participants were typically developing English-speaking children aged 4, 5, and 6 (50 per age group). Results showed more successful performance on all tasks as a function of age. In addition, all the children were more successful in the supported versus independent narrative context. Results are discussed in terms of the importance of oral narratives to social and educational milieus.
School-Related Stress and Depression in Adolescents With and Without Learning Disabilities: An Exploratory Study
Authors: Feurer D. Paige , Andrews Jac J.W.
Published: July 2024

This study examined school-related stress and depression in adolescents with and without learning disabilities. A total of 87 students (38 learning-disabled and 49 nondisabled) from secondary schools in Calgary completed questionnaires on depressive symptoms and on school-related stress. Results indicated that the adolescents with LD reported significantly higher levels of academic self-concept stress than their NonLD peers. However, the groups did not differ significantly on depression or on the other areas of school-related stress. Significant and positive correlations between school-related stress and depression were found, and the stress variables were found to be significant predictors of adolescent depression. Practical implications of the findings for parents and educators are discussed.
Background-Oriented Schlieren For The Detection Of Thermoacoustic Oscillations In Flames
Authors: Tasmany Sami , Kaiser Daniel , Woisetschläger Jakob , Gürtler Johannes , Kuschmierz Robert , Czarske Jürgen
Published: July 2024

Thermoacoustic oscillations are well known to combustion engineers. They are not only a cause of concern, but also give hope to be able to operate aircraft engines with hydrogen, due to flame stabilization and significant reduction of NOx emissions when thermoacoustically excited. The aim of this work is to investigate the potential of using a heterodyne background-oriented schlieren (HBOS) technique to detect thermoacoustic oscillations in the density field of an acoustically excited flame. It also seeks to address the issue of accuracy due to the small amplitude of thermoacoustic oscillations compared to turbulent density fluctuations in a flame. The experiment uses an unconfined swirl-stabilized methane flame and investigates thermoacoustic oscillations at about 3.4 kW power at ambient conditions excited by a siren at 225 Hz. The HBOS technique recently presented by the authors uses a carrier fringe system in background-oriented schlieren recordings, with subsequent analysis using evaluation techniques known from holographic interferometry. These fast algorithms reduce turbulence noise by phase averaging a large number of images. To derive local data from the line-of-sight projections, an inverse Abel transform is applied. Laser interferometric vibrometry is used to calibrate to the observed oscillations. A comparison with data from chemiluminescence is also presented to better demonstrate the application of this efficient technique to the detection of heat release oscillations. Future tasks in this project will deal with full-scale test benches and machine learning tools to address the limited observations in them.
Comparative Analysis Of Cycle-To-Cycle Variabilities And Combustion Development In An Optical Spark-Ignition Engine Fueled By Pure Hydrogen And Propane: Insights From Chemiluminescence and PI
Authors: Leite Caio Ramalho , Brequigny Pierre , Borée Jacques , Foucher Fabrice
Published: July 2024

Hydrogen, derived from renewable sources and devoid of carbon emissions, is a pivotal energy carrier for the future. Representing a viable substitute for fossil fuels in internal combustion engines (ICEs), contemporary studies advocate using very-lean and ultra-lean hydrogen-air mixtures, with a fuel-air equivalence ratio below 0.5, as a potent strategy to reduce NOx emissions in hydrogen-fueled ICEs. An experimental setup with an optical spark-ignition engine was devised to investigate the primary factors influencing cycle-to-cycle variations in H2ICEs by optimizing mixture homogeneity and focusing the study on flame interaction with in-cylinder aerodynamics. Simultaneous in-cylinder pressure, chemiluminescence, and PIV analyses were performed to characterize and compare the behaviors of ultra-lean hydrogen-air and propane-air flames, assessing flame development and cyclic variation features. Results indicate that the flame development of hydrogen and propane is significantly different. Propane exhibited increased in-cylinder pressure trace variability at lean and rich flammability limits with a high flame development difference between fast and slow cycles. In contrast, hydrogen-air mixtures under various equivalence ratios (from very-lean to ultra-lean) presented much more stable in-cylinder pressures. Furthermore, fast propane flames were mainly advected to the cylinder's symmetrical axes, while fast hydrogen flames started further away from the spark plug. Horizontal and vertical PIV measurements showed a single structure flow field over the studied conditions with mainly intensity variations over the measured cycles. Fast flames were associated with more intense tumble motion. The differences between fast and slow flames for hydrogen are attributed to the early flame development. However, after initial differences in flame development over several crank angles, there are similarities in all cycles, suggesting that the low variability in in-cylinder pressures is mostly due to the robustness of hydrogen flame ignition and its independence from in-cylinder flow small variations at the early development phase.
Cavitation Onset In Counter-Rotating Vortices From Diverging Disks
Authors: Costa Mariana , Fiscaletti Daniele , Westerweel Jerry
Published: July 2024

Cavitation occurs when the local pressure, induced by high local velocities, drops below the vapor pressure, leading to the formation of vapor bubbles. The subsequent collapse of these bubbles can cause noise, erosion, and vibrations. Recent studies show that cavitation is sensitive to water quality, i.e., the nuclei populations, the chemical composition of water, and the presence of particles. Motivated by investigating the effects of water quality on cavitation, experiments are performed in a dedicated experimental facility. This consists in two co-axial disks that are initially at rest and mutually in contact, in a tank filled with water. The fast diverging movement of the top disk with respect to the bottom one produces a jet flow inside the gap between the disks, which leads to the formation of two counter-rotating vortices. The local pressure drop induced by high flow velocities leads to a phase change. To characterize the phenomenon, two optical techniques are applied, i.e., shadowgraphy and particle image velocimetry (PIV). In performing PIV reconstruction, the sum of correlation enhances the spatial resolution of the velocity vector fields. The pressure field in the region where the vortices occur is obtained from velocity data. The water quality effects on cavitation are investigated by adding salt and using water with an abundance of nuclei inside the tank.
Mixing Of A Starting Turbulent Jet In Homogeneous And Isotropic Turbulence
Authors: Chen Chaoxu , Hardalupas Yannis , Taylor Alex
Published: July 2024

The mixing of a starting turbulent jet, injected with an injection velocity of U = 18.8 m/s from a tube with a diameter of D = 4mm (Reynolds number Re = 4800, characteristic time scale t* = D/U = 0.21 ms at the nozzle exit), is experimentally investigated in the presence of homogenous and isotropic turbulence (HIT) using Planar Laser-induced Fluorescence (PLIF). The root-mean-square (RMS) velocity of the ambient HIT is 0.38 and 0.63 m/s, corresponding to turbulent Reynolds numbers of Reλ = 190 and 250, respectively. Spatial distributions of mixture fraction and scalar dissipate rate (SDR) were measured within an axial range of y = 0 – 10 D and at different times after the start of injection (ASIs) up to 21.4 t*. Ambient HIT did not alter the location or size of the leading vortex ring in the initial formation stage. However, it was able to enhance the entrainment of ambient fluids in this stage and deform/transport both the leading and the trailing vortex rings at later stages, despite that the ASIs examined were only comparable to its Kolmogorov timescale. Ambient HIT also introduced a significant increase to the fluctuations of the jet penetrations length but only a marginal reduction (less than 10%) to the averaged jet penetration speed. PDFs of the ensemble averaged mixture fraction within the whole jet region showed increased probability of low mixture fraction values – and therefore indicating enhanced entrainment and mixing – in the presence of ambient HIT. Ensemble averaged distributions of the SDR showed no significant alterations by the ambient HIT in the initial formation stage of the leading vortex ring. At later stages, while the high SDRs in the leading vortex ring remained concentrated in a layer along the edge of the vortex ring for Reλ = 0, it became increasingly uniformly distributed with a lower maximum value as the ambient HIT increased. Similar, but less significant, impact of the ambient HIT on the SDR fields was observed in the trailing vortex rings, while no noticeable impact was found in the shear layer close to the nozzle exit.
NGHIÊN CỨU BƯỚC ĐẦU KẾT QUẢ CHỤP VÀ NÚT MẠCH TRONG ĐIỀU TRỊ CHẢY MÁU TIÊU HÓA DƯỚI
Authors: Trần Doãn Khắc Việt , Võ Tấn Đức , Phạm Ngọc Minh Triết , Đặng Quốc Việt , Nguyễn Hoàng Bắc
Published: July 2024

Đặt vấn đề: Chảy máu tiêu hóa dưới là một cấp cứu nguy hiểm đặc biệt trong trường hợp nội soi tiêu hóa thất bại hay không tiếp cận được. Cùng với sự phát triển và áp dụng các kĩ thuật xâm lấn tối thiểu, chụp và nút mạch cầm máu số hóa xóa nền ngày càng được áp dụng nhiều hơn bên thay thế phẫu thuật trong các trường hợp này.
Mục tiêu nghiên cứu: đánh giá kết quả bước đầu chụp và nút mạch trong điều trị chảy máu tiêu hóa dưới
Phương pháp: báo cáo loạt ca
Kết quả: Từ tháng 01/2019 đến tháng 01/2022, có 35 lượt thủ thuật trên 24 bệnh nhân được thực hiện, trong đó 12 trường hợp chụp mạch chẩn đoán và 23 trường hợp nút mạch cầm máu. Tỉ lệ cầm máu thành công về kĩ thuật là 95%, tỉ lệ cầm máu thành công về lâm sàng là 81.8%. Không có trường hợp hoại tử hay thủng ruột.
Kết luận: Chụp và nút mạch cầm máu là kĩ thuật hiệu quả và an toàn trong kiểm soát chảy máu tiêu hóa dưới với tính xâm lấn tối thiểu.
TƯƠNG QUAN GIỮA ĐƠN VỊ HOUNSFIELD Ở CỘT SỐNG THẮT LƯNG VÀ MẬT ĐỘ XƯƠNG ĐO BẰNG DEXA
Authors: Nguyễn Thị Minh Trang , Nguyễn Thị Thùy Linh , Phạm Vũ Mỹ Phụng
Published: July 2024

Đặt vấn đề: Loãng xương là bệnh lý làm tăng nguy cơ gãy xương. Đánh giá đơn vị Hounsfield (HU) ở cột sống thắt lưng (CSTL) trên chụp cắt lớp vi tính (CLVT) vì lý do bất kỳ có khả năng dự đoán bất thường mật độ xương góp phần cảnh báo loãng xương.
Mục tiêu: Đánh giá mối tương quan của HU tại CSTL với kết quả mật độ xương (BMD) đo bằng phương pháp hấp thụ tia X kép (DEXA).
Đối tượng và phương pháp nghiên cứu: Nghiên cứu hồi cứu và cắt ngang mô tả trên 150 bệnh nhân (BN) có thực hiện CLVT qua vùng bụng vì bất cứ lý do nào và DEXA cách nhau không quá 6 tháng. Đo HU tại các thân sống thắt lưng từ L1 đến L4. Đối chiếu với kết quả DEXA, tính hệ số tương quan Spearman của HU và BMD, tính diện tích dưới đường cong (AUC) và chọn điểm cắt HU để phân biệt giữa nhóm bình thường và thiếu xương – loãng xương, giữa thiếu xương và loãng xương.
Kết quả: Có mối tương quan thuận có ý nghĩa giữa HU trung bình tại cột sống thắt lưng (từ L1 đến L4) và mật độ xương đo bằng DEXA, tương quan mạnh nhất tại thân sống L2 (hệ số tương quan Spearman là 0,68). HU thân sống L2 ≥ 131 HU tương ứng mật độ xương bình thường, 101 – 131 HU tương ứng thiếu xương, ≤ 101 HU tương ứng loãng xương (độ nhạy và độ đặc hiệu #70%). Trong phân biệt mật độ xương bình thường và thiếu xương – loãng xương, ngưỡng cắt ≥ 101HU có Se ≥ 90% và ngưỡng cắt ≥ 171 HU có Sp ≥ 90% cho nhóm bình thường; trong phân biệt thiếu xương và loãng xương ngưỡng cắt ≤ 132 HU có Se ≥ 90% và điểm cắt ≤ 62 HU có Sp ≥ 90% cho nhóm loãng xương.
Kết luận: Có mối tương quan có ý nghĩa giữa HU tại CSTL và BMD đo bằng DEXA. HU tại CSTL có giá trị trong dự báo tình trạng bất thường mật độ xương.
Từ khóa: loãng xương, phương pháp hấp thụ tia X kép, đơn vị Hounsfield tại cột sống thắt lưng.
Impact of Chlorella vulgaris biomass substitution on in vitro bioaccessibility of cookies
Authors: Dündar Ayşe Neslihan , Aygün Ahmet , Şahin Oya Irmak
Published: July 2024

This study aimed to produce low-fat cookies (C) by substituting Chlorella vulgaris biomass (0.5% CB1, 1.0% CB2, and 1.5% CB3) and investigating the bioavailability of minerals, total phenolic content, and antioxidant capacities of the cookies. Chlorella sp. microalgae is recognized for its high phenolic content, antioxidant capacity, and as a source of essential minerals. Extractable and hydrolyzable fractions were prepared to determine the total phenolic content and antioxidant capacity. The total phenolic content of CB samples ranged from 200.82 to 274.07 mg GAE/g, with bioaccessibility values from 32.31 to 47.26 mg GAE/g. The CUPRAC method provided the highest antioxidant capacity values (116.57-154.38 µmol TE/g), while the ABTS method showed the highest bioaccessibility values (6.76-9.21 µmol TE/g). Mineral content analysis (Na, Mg, P, K, Ca, Mn, Fe, Cu, Zn, and Se) revealed significant enhancements in the CB samples compared to controls, showing an approximate 2-fold increase in mineral bioaccessibility. Despite extensive research on microalgae-fortified foods, there is a notable gap in knowledge regarding their "in vitro bioaccessibility." This study aims to pioneer the exploration of bioaccessibility and highlight the positive impact of algae-based food consumption on human health.
Evaluación del tecnoestrés en trabajadores del área administrativa del consorcio aero-suspendido de Guayaquil
Authors: Sarabia-Ramírez Carlos Roberto , Cabezas-Heredia Edmundo
Published: July 2024

El uso de las tecnologías se ha introducido con rapidez en el mundo laboral, su uso y abuso ha generado diversas formas de trabajo y de organización de las empresas, sin embargo, las tecnologías pueden crear exigencias para el trabajador que, en ocasiones, es incapaz de asumir bien, sea por falta de información, adaptación o por el uso inadecuado de las mismas, ocasionando serios problemas de salud a los trabajadores, esto ha dado  lugar a la aparición de nuevos riesgos psicosociales en el trabajo, como el tecnoestrés. La presente investigación se realizó en el área administrativa del Consorcio Aéreosuspendido de Guayaquil, cuyo objetivo es determinar los niveles de tecnoestrés en los trabajadores. Se aplicó el test de tecnoestrés (NTP 730), y se complementó con variables sociodemográficas. La población encuestada fue de: 25 trabajadores. El resultado encontrado sobre los niveles de tecnoestrés: 72 % bajo, 24 % medio y 4 % alto, se estableció la correlación por medio del V de Cramer de las variables sociodemográficas y el test aplicado. Se concluye la presencia de niveles de tecnoestrés bajo en la mayoría de los trabajadores con pocos casos de niveles medios y altos, lo que revela la necesidad de implementar un manual de prevención para mitigar los efectos negativos para la salud física y mental.
Elektromanyetik girişim koruması için termoplastik poliüretan kompozitler
Authors: Kaya Ümmühan , Kaftelen Odabaşı Hülya
Published: July 2024

Gelişen teknoloji ile birlikte elektronik cihazlara olan ilginin olumsuz bir etkisi elektromanyetik kirlilik olmuştur. Bu yüzden elektromanyetik girişim (EMI) kalkanlama malzemeleri önemli hale gelmiştir. Yüksek yoğunluklu ve düşük korozyon direncine sahip metaller çoğunlukla iletkenlik özellikleri nedeni ile tercih edilse de bu dezavantajlarından dolayı, hafif, yüksek mukavemet ve yüksek korozyon direncine sahip polimerler kompozitlere ilgi artmıştır. Termoplastik kompozitler hafif, kolay işlenebilir ve geri dönüştürülebilir olmaları nedeni ile geniş bir uygulama alanlarında kullanılmaktadır. Elektromanyetik girişim kalkanlama prensibine dayalı olarak, birçok karmaşık faktör, iletken polimer kompozitler için istenen kalkanlama verimini elde etmede etkili bir role sahip olduğu görülmüştür. Bunlar, iletken polimer kompozitlerin iletkenlik özelliklerini büyük ölçüde etkileyen nanopartiküllerin türü, morfolojisi, miktarı ve dağılımını içerir. Yüzey iletken tabakası veya yüksek içerikli metal dolgulu ürünler, esas olarak yansıma yoluyla iyi elektromanyetik girişim koruması sağlar, ancak genellikle yüksek yansımaya yol açarak güçlü ikincil elektromanyetik radyasyona neden olabilirler. Dolayısı ile yansıma tabanlı EMI koruma, yalnızca kalkanlama malzemesiyle girişimi önleyebilir, ancak kayıp elektromanyetik dalgaları etkili bir şekilde kontrol edemez ve ortadan kaldıramaz. Bu nedenle, ikincil elektromanyetik dalga kirliliğini ortadan kaldırmak manyetik nanopartiküller ile karbon esaslı (karbon fiber gibi) hibrit malzemelerinin iletken polimer kompozitlerin absorpsiyon özelliğini desteklemek için ilave edilmesi ile sağlanabilir. Burada, manyetik nanoparçacıklar manyetik kayıp sağlarken karbon nano dolgu maddeleri, soğurma yoluyla elektromanyetik dalgaları daha etkili bir şekilde dağıtabilen dielektrik kaybına katkıda bulunur. Kalkanlama verimini etkileyen bir diğer önemli faktör ise, polimer kompozitlerin yapısal özelliklerinin (yığın veya 3 boyutlu gözenekli yapıya sahip olması) etkisidir.
Poliüretan termoplastikler, esnek, hafif, ekonomik olmaları ve üç boyutta gözenek yapılı şekilde üretilebilmeleri nedeniyle EMI koruması açısından önemlidir. Grafen, karbon siyahı, karbon fiber gibi karbon esaslı malzemelerin polimer matrisine ilave edilmesi ile mekanik, elektriksel iletkenlik ve termal özelliklerinde iyileşme sağlanır. Bu nedenle, karbon esaslı malzemeler, elektronik cihazlarda elektromanyetik girişimi engellemek için potansiyel olarak etkili bir seçenek olarak kabul edilebilir.
Verantwoordingsverplichtingen Aanzet BVm
Authors: van Rookhuijzen J.
Published: July 2024

Verantwoordingsverplichtingen Aanzet BVm; een dosis inspiratie van over de grens

In afwachting van het verschijnen van het wetsvoorstel voor de maatschappelijke bv pleit de auteur in deze bijdrage voor aanscherping van de, in de Aanzet BVm voorgestelde, verantwoordingsverplichtingen voor het bestuur van de (toekomstige) maatschappelijke onderneming. Hierbij wordt inspiratie ontleend aan het Franse model van de société à mission.