bluuebunny/crossref_metadata_2025 huggingface dataset:
Efectos de la pandemia en las finanzas de las empresas grandes del sector profesional, científico y técnico
Authors: Preciado Miranda Ángel Steven ,   Universidad Politécnica Salesiana (Ecuador), Pilco Chucho Sara Débora , Paredes Floril Priscilla Rossana ,   Universidad Politécnica Salesiana (Ecuador),   Universidad Politécnica Salesiana (Ecuador)
Published: July 2024

El COVID-19 representa una crisis sin precedentes, donde la respuesta principalmente de los gobiernos de todo el mundo para sobre llevarla, fue en su momento bastante dramática. Dado que estos buscaban responder y darles frente a las instituciones multilaterales, incluidos el Fondo Monetario Internacional (FMI) y el Banco Mundial, así como los productores de conocimientos, especialmente los proveedores de datos y los analistas. Por ello, las respuestas de los gobiernos variaron mucho en todo el mundo, aun cuando incluyeron medidas económicas, políticas y sociales menos severa, para darle frente a este mal, esto condujo a que muchos dueños de negocios tomaran medidas para mantenerse seguros frente a los empleados y clientes y sobre todo protegerse de posibles responsabilidades (Castro, 2020). Esto conllevó a una movilidad descontrolada y a una economía cada vez más fluctuante que no conseguía un equilibrio a nivel mundial.
Population survey and habitat selection of the European Nightjar (Caprimulgus europaeus L.) in the Győr-Gönyű sand steppes
Authors: Bodor Ádám , Winkler Dániel
Published: July 2024

This study investigated the habitat selection of the European Nightjar (Caprimulgus europaeus) during the breeding seasons of 2017 and 2018 in the Győr-Gönyű calcareous sand steppe area. In order to assess the habitat preferences of the European Nightjar, habitat characteristics around occupied territories were compared with unoccupied control plots. To characterize the surveyed territories, a total of nine variables related to landscape characteristics, vegetation structure, and composition were quantified. Multivariate methods (PCA and GLMs) were used to distinguish the main factors influencing habitat selection and to model the presence of the European Nightjar. A total of 25 occupied territories were surveyed in the study area in 2017, while 21 in 2018, all of which were characterized by mosaic-structured habitats. Based on our results, in the Gönyű sand steppes, a high probability of European Nightjar presence can be predicted in plots with a sufficient proportion of bare ground patches, higher lengths of forest edges, and the presence of grasslands near the territories.
Vércse költőláda kihelyezések tapasztalatai a Mosoni-Síkon
Authors: Győrig Előd , Bodics Dániel , Spakovszky Péter , Váczi Miklós , Winkler Dániel
Published: July 2024

The Mosoni Plain Natura 2000 site is one of the most western nesting sites of the strictly protected Red-footed Falcon (Falco vespertinus) in Hungary, and the Common Kestrel (Falco tinnunculus) is the most common nesting bird of prey in the area. The breeding success of these two species, which do not build nests, can be greatly enhanced by the installation of good quality and properly placed artificial nests boxes. Monitoring of the artificial nest-boxes was previously not regularly and entirely conducted. However, from 2019 onwards, the now nearly 100 active nest-boxes are being regularly monitored, recording nest occupancy, clutch size and fledging data for Red-footed falcon, Common Kestrel, as well as for the Long-eared owl. The presenent paper summarises the nesting records of these three species on artificial breeding sites on the Moson Plain. During the period 2019–2023, we observed a total of 12 Red-footed Falcon breedings, 7 of which were in artificial nestboxes. On average, 3.0 chicks were successfully fledged from the boxes. Regarding Common Kestrel, a total of 121 breedings were recorded in nesting boxes, of which more than 80% were successful. On average 3.84 chicks fledged per nest box. During the 5 years of the study, a total of 14 pairs of Long-eared Owl breeding were associated with artificial nest-boxes, of which 10 proved successful. A total of 35 chicks fledged successfully.
Ökológiai vizsgálatok Sopron város madárfaunájáról
Authors: Szolnyik Csaba , Winkler Dániel
Published: July 2024

This paper presents the results of an ecological study on the urban avifauna of Sopron. Bird surveys were carried out in six different urban green areas during the period 2006–2007. A total of 81 bird species were recorded, 56 of them are breeding species. Based on the zoogeographical analysis, the species that occurred belong to 13 faunal units. Palearctic, European, and Euroturkestan species are dominating, but at the same time, the percentage of Holarctic species is also notable. Bird species richness was the highest in the University Botanical Garden, while the lowest species richness was found in the Széchenyi Square area. The relative species richness calculated for the avifauna of Sopron was relatively high (RSR=26,54). Similarity measures and hierarchical cluster analysis based on the Simpson index clearly showed the high similarity between the two most disturbed areas (Széchenyi Square and Jereván Housing Estate) as well as between the two most natural-like areas (Sörházdomb and Botanical Garden).
Vadgazdálkodás és vadászat herceg Festetics Tasziló birtokain
Authors: Faragó Sándor
Published: July 2024

In the last third of the 19th century, in addition to extensive hunting, conscious management and stock control became characteristic, either in free-range farming or in captive breeding. In this new approach to management, Hungarian gamekeepers took part in different ways and with different emphasis due to the ecological features, such as Count LAJOS KÁROLYI in Tótmegyer (FARAGÓ 2017, 2023), Markgraf (Marquess) ALFONZ PALLAVICINI in Pusztaszer (PINJUNG, 2021) and Prince TASZILÓ FESTETICS in Berzence. In this work, we review the hunting and game management activities of Prince TASZILÓ FESTETICS (1850– 1933). We discuss his Red Deer hunts and their results, the results of the small game hunts, in which he played a prominent role hand reared Pheasant. We present the list of important aristocrats who participated in the hunts from the point of view of Hungarian history, and separately the so-called royal hunts. The following rulers or archdukes took part in the latter: Prince LOUIS II of Monaco, King ALBERT of Saxony, King EDWARD VII of England (when he was heir to the throne), Archduke RUDOLF, crown prince of Austria, Archduke FRANZ FERDINAND of Austria, and Archduke FRIEDRICH, Duke of Teschen. We consider Prince TASZILÓ FESTETICS to be one of the most prominent figures in Hungarian hunting history.
Havacılık uygulamaları için açık kaynaklı parametrik bir aerodinamik şekil optimizasyon çerçevesinin geliştirilmesi
Authors: Batan Buğra , Abuhanieh Saleh , Çalışıır Tamer , Yiğit Şahin
Published: July 2024

Sürekli büyüyen havacılık sektöründe uçuş sayısının artması nedeniyle uçakların karbon ayak izi de artış göstermektedir. Uçakların aerodinamik performansının iyileştirilmesi kritik bir gereklilik haline gelmiştir. Bu nedenle, uçak bileşenlerinin tasarımında aerodinamik şekil optimizasyonu (ASO) büyük önem taşımaktadır. Bu çalışmada, transonik rejimde N2A-EXTE hava aracının geometrisi optimize etmek için açık kaynaklı araçlar kullanılarak hesaplamalı akışkanlar dinamiği (HAD) tabanlı parametrik bir ASO çerçevesi tasarlanmıştır. Sunulan ASO çerçevesi kullanılarak elde edilen sonuçlar, N2A-EXTE hava aracı için maksimum olarak %10’luk göreceli iyileştirme yaptığını göstermiştir. Optimize edilmiş aerodinamik yüzeylerin üzerindeki basınç dağılımı ve süpersonik bölgelerin başlangıç geometrisi ile kıyaslanması sonucunda yapılan göreceli iyileştirmenin nedenleri ortaya konmuştur. Ayrıca N2A-EXTE hava aracı için oluşturulan yeni tasarımlar için hacim, yüzey alanı ve boylamsal statik kararlılık karakteristiği açısından orijinal hava aracı geometrisi ile kıyaslanmıştır. Gerçek bir hava aracı üzerinde yapılan optimizasyon çalışmaları mevcut çalışmada önerilen ASO çerçevesinin yeterince kararlı olduğunu ve iyi çalıştığını ortaya koymuştur. Bu çalışmada tasarlanan ASO çerçevesinde yer alan açık kaynak yazılımlar başka tasarım araçları ile yer değiştirilebilir olup farklı havacılık uygulamalarında ve hava araçlarının ön tasarım aşamalarında kolaylıkla kullanılabilmektedir. Mevcut çalışmada sunulan ASO çerçevesi gelecekte yapılacak çok disiplinli ASO çalışmasının ilk adımı olarak düşünülebilir.
¿Las TIC pueden contribuir al aprendizaje de las 3Rs y el cuidado del medio ambiente en I4?
Authors: Huertas Machuca Estela
Published: July 2024

El paradigma social actual, por un lado, está muy vinculado con las Tecnologías de la Información y la Comunicación (TIC), las cuáles se han introducido de forma masiva, incluso en el ámbito de la educación; por otro lado, el cambio climático y sus notorias consecuencias están alterando nuestra cotidianidad. Así pues, la presente intervención educativa, desarrollada en un aula de I4 y cuya metodología es constructivista, contiene un doble objetivo: (1) introducir las TIC, concretamente, la Pizarra Digital Interactiva (PDI) y las tabletas, para acercar al alumnado al mundo digital y (2) impulsar actitudes de respeto y protección hacia el medio ambiente, minimizando la contaminación y practicando el reciclaje desde el aula. Los resultados obtenidos tras su implementación reflejan que el alumnado ha logrado un primer acercamiento a los dispositivos empleados, además de haber aprendido sobre la separación selectiva y las 3Rs (término referido a la reducción, reutilización y reciclaje de residuos). Finalmente, estas evidencias han permitido concluir que aplicar las TIC en Educación Infantil, no solo es posible, sino que, contribuye al aprendizaje significativo del alumnado.
EFL Learners’ Attitudes Towards Utilizing ChatGPT for Acquiring Writing Skills in Higher Education: A Case Study of Computing Students
Authors: Al-Alami Suhair E.
Published: July 2024

The rapid technological advancements have recently paved the way for a new era of language instruction. Amongst the technological tools which have emerged recently is ChatGPT. This study explores students' attitudes towards utilizing ChatGPT for acquisition of writing skills in English as a foreign language (EFL). Conducted during the first semester of the academic year 2023-2024, the study involved fifty-two students at a private university in Sharjah who were taking an English language course during the implementation of this study. The study used a mixed-methods design to investigate students' attitudes and quantify the findings. Two study tools were employed: a questionnaire and a semi-free interview. Comprising ten items, the questionnaire measured students' attitudes towards using ChatGPT for acquiring writing skills whilst at the same time focusing on higher-order thinking skills as they are related to effective writing. The semi-free interview, on the other hand, included the advantages and drawbacks of utilizing ChatGPT-based essay writing versus self-dependent essay writing. The findings indicated that most subjects confirmed ChatGPT's effectiveness in saving time and ensuring language accuracy. However, the progress one could make in acquiring writing skills and enhancing higher-order thinking abilities could not be seen significant. The paper concludes with recommendations for researchers to consider.
University Students’ Plagiarism Behaviours in Writing Instruction: A Systematic Review
Authors: Rustan Edhy
Published: July 2024

The literature indicates that students' understanding of plagiarism and academic writing skills impact their plagiarism behaviour. However, there has yet to be a review that explores the methods, supporting tools, and content of writing instruction that can effectively reduce plagiarism behaviour at the university level. Therefore, this systematic review aims to present academic writing instruction that can prevent plagiarism behaviour. The review data was derived from four different databases, EBSCO, Wiley, Proquest, and JSTOR, published from 2010 to 2022. The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) standards were used to ensure that the review was systematically carried out. Based on the 22 articles reviewed, tutorial methods and workshops were most used to provide knowledge on plagiarism, followed by writing skills content, and guided writing practice. Writing skills content comprised word choice, grammar, citation, paraphrasing, and referencing concerning plagiarism prevention. This study also found that Rubrics and Turnitin applications were widely used as supporting tools for plagiarism checking and as feedback for the students. Implementing writing instruction coupled with plagiarism education and feedback can change students' plagiarism behaviour and improve their confidence in academic writing.
Transformative Impact of Teacher Activity Groups on Vietnamese K-12 Teachers’ Professional Growth: A Study of Satisfaction
Authors: Yen Phuong Hoang , Lunney Helen , Thi Nguyen Anh , Thuy Pham Trut , Tra Nguyen Huong , Thu Huynh Thi Anh , Thao Le Thanh
Published: July 2024

This study aims to examine the satisfaction of Vietnamese K-12 teachers with the impact of Teacher Activity Groups (TAGs) on their professional development (PD). In the context of a rapidly evolving education system, PD plays a crucial role in enhancing teachers’ knowledge, skills, and effectiveness in the classroom. Collaborative approaches, such as TAGs, have gained attention as promising strategies for fostering teacher growth and satisfaction. However, limited research has explored the specific impact of TAGs in the Vietnamese context. To address this gap, a quantitative approach was employed, and data were collected using a questionnaire from 147 K-12 teachers. The questionnaire consisted of 21 items measured on a 5-point scale, assessing various aspects of participants’ satisfaction with the TAGs program. The results reveal high levels of overall satisfaction with the TAGs program, indicating positive perceptions of its interest, value, usefulness, and impact on professional development. Notably, variations in satisfaction levels were observed in relation to learner attendance and dropout rates. These findings provide valuable insights for educational policymakers and school administrators in designing and implementing effective PD initiatives tailored to the specific needs of teachers and students. By promoting teacher satisfaction and growth, TAGs have the potential to contribute to the continuous improvement of the Vietnamese education system.
A Linguistic Investigation Into False Friends in Arabic and English: The Students of Al-Balqa Applied University as a Model
Authors: Abu-Snoubar Tamador Kh. , Abumahfouz Adnan M. , Shboul Yasser I. , Aldowkat Issam M. , Rahahleh Ahmad Z.
Published: July 2024

The present study investigates the concept of false friends in two genetically unrelated languages: Arabic and English. It provides explanations for the source of possible confusion and misunderstanding caused by false friends in contemporary Arabic and English. It also highlights the nomenclature related to false friends where they can be classified into two categories: absolute false friends and partial false friends. The study explicates how false friendship, as a linguistic phenomenon, can be a real hurdle to communication among the learners and teachers of a certain language. The etymological development of some words is very important to explain how false friendship occurs. Morphologically, some special cases of intralingual morphological false friends are explored in so far as they are related to the concept of false friendship to put them into a certain linguistic framework.
An Exploration of EFL Teachers’ Perceptions of Using Game-Based Learning Tools in Virtual Classes in a Saudi Primary School Context
Authors: Al-Harbi Ghidaa Mohammad , Madini Abeer Ahmed
Published: July 2024

The recent trend towards digitization in education sectors, driven by the growing demand for more personalized learning, the health pandemic crisis, and the need to improve accessibility to diverse pedagogies, has transformed approaches to teaching. Specifically, the creation of digital game-based learning (DGBL) in recent years has led to an increased appreciation of the potential offered by digitization and the new trends toward gamified and virtual learning. This study explores the benefits of and challenges associated with learning gamification, as well as EFL teachers’ perceptions of using gamification tools in five primary schools in Al-Qunfudhah school district, Saudi Arabia. The study employed a qualitative design to obtain comprehensive data. Non-probabilistic purposive sampling was used to recruit a representative sample comprising five EFL teachers (N=5) from different primary schools. Furthermore, the study performed semi-structured interviews (SSIs) with participants to acquire in-depth insights based on their perceptions and experiences with DGBL. A thematic analysis (TA) was chosen as the primary strategy for analyzing qualitative data and coding participants’ insights into key themes and sub-themes. Overall, statistical measures indicated that many EFL primary school teachers in Al-Qunfudhah had effective technological awareness. Given the positive perception of DGBL, the study suggests that EFL teachers are able to integrate DGBL strategies to facilitate virtual learning, improve student-teacher engagement, increase time efficiency, and support language development.
The Representation of Nature in Ibn-Khafaja’s and Wordsworth’s Poetry: A Comparative Stylistic Study of Selected Poems
Authors: Ibrahim Abdullah M. , Pérez María de las Mercedes Delgado , Abuhammam Emad A.
Published: July 2024

This study analyzes the depiction of nature in poetry, especially in Ibn-Khafaja’s and Wordsworth’s selected poems. This study is based on New Criticism's conceptual, analytical, and theoretical approaches. New Criticism studies the achievement of the works’ meanings by studying their “interrelationships of sound, texture, structure, rhetoric, and a host of other literary devices” (Bressler, 2011, p. 57). The significance of the study is to provide a parallel comparative study between these two poets whose religions, traditions, languages, and eras are dissimilar. Ibn-Khafaja recognizes his surrounding nature as the ideal and beautiful place where people feel relaxed, hopeful, and pleased. He states that humankind and nature are originally adapted to each other, and people are always fascinated by the beauty of nature. He sees nature as the typical shelter to stay happy and peaceful. He is fascinated by the images of the mountains, horses, birds, and trees. On the other hand, Wordsworth shows nature as a place of happiness, perfectness, and peace. He accentuates the deep relationship between human beings and nature, and how people admire nature in its beautiful images. Wordsworth presents how the fascinating images of nature can affect man’s mood and mind.
Factors Influencing Preservice EFL Teachers’ Technology Integration Into Language Teaching
Authors: Junhong Tang , Lim Jia Wei , Tee Meng Yew
Published: July 2024

In the 21st century, preservice EFL teachers must be able to integrate technology into language education. However, very little research has been carried out on the specific factors that influence preservice teachers to integrate appropriate technology into their language teaching. This study aimed to explore exactly what influences preservice EFL teachers to choose the appropriate technology to incorporate into their lessons through a two-cycle design-based research study. The findings suggest that preservice EFL instructors' comprehension of language teaching methods and approaches has the greatest influence on technological integration in their classrooms. In addition, the instructor’s direct guidance also facilitates their appropriate technology integration into language teaching. As a result, teacher education programs are designed to provide preservice EFL instructors with language teaching methods and approaches before assisting them in learning how to incorporate appropriate technology into specific language teaching methods or approaches. Finally, the researchers suggest that instructors also provide direct advice to preservice EFL teachers as they explore the incorporation of technology into language education.
Faculty Members’ Perspective on Employing YouTube in Teaching English for ESL Undergraduate Students
Authors: Ammari Reada M. , Ahmad Wajed R. Al , Abushunar Majd S. , Al-Jarrah Lina A.
Published: July 2024

The study investigated the use of YouTube videos for teaching English as a foreign language to English major students at universities and explored teachers' perspectives on implementing this method. It also aimed to identify potential issues that teachers and students might encounter. A mixed-method approach combining quantitative and qualitative data collection was employed. A Five-Likert scale questionnaire assessed teachers' perspectives on using YouTube to teach various English language skills. The study involved 42 English language faculty members from private and public universities, and their responses were analyzed statistically and analytically. The findings indicated that teachers have a positive attitude as they successfully utilize YouTube videos to improve students' English language skills. Faculty members observed that the monotony of teaching decreased while students' motivation to engage with the English language increased. The study also revealed some challenges students face in developing their English language skills, such as a lack of self-confidence and an inability to express their thoughts adequately.
Raising Awareness of Gender Discrimination Against Indigenous Australian Women of the Stolen Generation Through Doris Kartinyeri’s Kick The Tin
Authors: Rorintulus Olga A. , Saktiningrum Nur , Wuntu Ceisy Nita , Hafizh Muhd. Al , Mamentu Agustine C.
Published: July 2024

In contemporary society, the persistent manifestation of gender discrimination continues to impede the advancement of women in their pursuit of gender equality. Within the historical context of the assimilation program, Indigenous Australian women confronted systemic gender disparities. This scholarly investigation endeavors to elucidate the nuanced facets of gender discrimination experienced by Indigenous Australian women affiliated with the stolen generation, as discerned through the lens of Doris Kartinyeri's seminal work, "Kick the Tin." Employing a qualitative research paradigm, this study uses a liberal feminist framework to scrutinize the gathered data meticulously. The findings underscore that Kartinyeri's "Kick the Tin" unveils the entrenched gender discrimination endured by Indigenous Australian women during the assimilation era, delineating their prescribed roles as domestic laborers within the prevailing white societal framework, thereby perpetuating the marginalization of this demographic. In its essence, the narrative challenges the systemic marginalization of Indigenous Australian women, concurrently advocating for their empowerment as a catalyst for fostering an equitable societal milieu. Consequently, this research augments scholarly discourse, serves as a poignant catalyst for heightened social consciousness, and catalyzes imperative shifts toward mitigating the pervasive impacts of gender discrimination on a broader scale.
A Syntactic and Discoursal Analysis of halaʔ ‘Now’ in Jordanian Arabic
Authors: Al-Daher Zeyad , Al-Dala’ien Othman Aref , Al-Rousan Mohammad , Sahawneh Meera B. , Bader Saada
Published: July 2024

This study investigates the syntactic behavior and the discoursal roles of halaʔ in Jordanian Arabic, which corresponds to the English ‘now’ and is frequently used as a discourse marker. Specifically, the syntactic distribution of this discourse marker in everyday conversations, its function in establishing coherence between discourse units, and its communicative and discoursal meanings are scrutinized. The data necessary for the study was obtained from almost a 15-hour corpus of naturally-occurring conversations recorded by the researchers through 30 interviews with 80 (40 males and 40 females) Jordanian students from Al-Balqa Applied University. The data analysis revealed that halaʔ can be used as an adverb conveying temporal meaning and as a discourse marker conveying coherence-related meanings. Semantically, it is a temporal adverb that has a semantic meaning parallel to that of its English adverbial counterpart ‘now’. However, it was found that halaʔ can also serve six pragmatic functions: Changing a topic, introducing a contrast or comparison, marking disagreement, initiating reasons, explanations or clarifications, listing, and marking shifts in participation framework (Marking a change in the speaker’s orientation and marking a change of footing). The study concludes with a suggested grammaticalization path for the development of this discourse marker from a lexical source.
Judicialização em saúde e atuação defensorial em caso de insumo não incorporado: a demanda de Canabidiol na Defensoria Pública Federal de Salvador/BA durante a última década
Authors: Villas-Bôas Maria Elisa
Published: July 2024

Objective: To evaluate the performance of the Federal Public Defender's Office and the effectiveness of the juridification of health, as an instrument to guarantee access to the right, in the case of a non-standardized input (Cannabidiol), in the Salvador/Bahia unit. Methodology: a descriptive study with application of retrospective longitudinal method was carried out on the number of Cannabidiol claims that have reached the unit since the index case admitted in Brazil in 2014, its annual evolution and destination in the institution and in the court, until 2023. Results and discussion: there was a systematic growth in the number of cases, which doubled annually, especially from 2018 onwards, except in 2021. The percentage of judicialized lawsuits was about 59%, and, among those, more than half obtained a favorable decision in some instance, reaching 76% from the merit sentences. The time between the arrival of the applicant, the gathering of documents and the filing of the action was, on average, 2.4 months, and the average interval between the filing of the initial petition and the intimation of the anticipation decision, in the cases where it was granted, was 2 months. On the other hand, the interval between the intimation of the anticipatory decision and the effective compliance oscillated around 9.2 months, only being obtained through judicial blocking in almost 70% of the cases. Conclusion: it was found that the defense was swift, as soon as the necessary documents were gathered, as well as the injunctions granted. On the other hand, the time of compliance after the concession decision showed an alarmingly long interval, resulting in a new form of ineffectiveness of the social right to health, which the judicialization aimed precisely to combat.
Submission: 11/30/23| Review: 01/29/24| Approval: 01/30/24
The Phenomenon of Schoolshooting and Its Interpretation in the Context of Legal and Psychological Knowledge and Associative Meanings of Future Investigators
Authors: Borisova S.E.
Published: July 2024

The reality and severity of the consequences of the phenomenon of schoolshooting*, which has distinctive features that make it possible to recognize it among criminal events, are stated. The imperfection of the definitions of schoolshooting is emphasized, and the need for its interdisciplinary analysis and study by future investigators within the framework of the discipline “Legal Psychology” is stated. The purpose of the study is to identify the features of associative representations of students (future investigators) about schoolshooting and to reveal the semantic content of conceptual connections, based on modern legal and psychological provisions. The survey data were obtained using the association method and are subject to mathematical processing. The main results correlating with the hypotheses are to determine the spectrum and structure of associative ideas about schoolshooting; to establish the consistency of associative ideas with scientific information; to identify the understanding, but at the same time insufficient use of psychological terms by cadets; to characterize schoolshooting based on filling associative-conceptual connections with scientifically based content.
Comparison of HIV prevention strategies for persons with serious mental illness
Authors:   , Campbell Elizabeth Harkey
Published: July 2024

Although HIV education and prevention efforts have been directed towards the general population as well as the gay community and intravenous drug users, persons with serious mental illness are among those who have not been targeted for extensive education and prevention efforts. Those interventions that have been utilized with this population have not used rigorous design and evaluation procedures, resulting in poor generalizability. This investigation assessed the HIV knowledge and risk behaviors of 47 individuals with serious mental illness within the context of a community mental health center partial hospitalization program. The purpose of this investigation was to compare two different programs for the prevention of HIV in persons with serious mental illness to determine which was most successful in increasing knowledge and decreasing risk behaviors. This study utilized a pretest-posttest control group design. Both interventions resulted in lower levels of reported HIV risk behavior at posttest as compared to a wait list control group. For subjects who completed five or more treatment sessions, those in the drop-in model group reported fewer HIV risk behaviors. Significant changes in HIV knowledge were restricted to an open-ended measure for those subjects who attended five or more treatment sessions of the drop-in group. Future investigations are needed that focus on the effects of social desirability on reports of HIV risk behaviors, as well as the possible mechanisms responsible for changes in HIV risk behavior as a result of these interventions.
Laser desorption/laser ionization time-of-flight mass spectrometry instrument design and investigation of the desorption and ionization mechanisms of matrix-assisted laser desorption/ionization
Authors:   , King Richard C.
Published: July 2024

This thesis contains two sections of related research. The first section focuses on improving the performance of laser desorption/ionization time-of-flight mass spectrometers. It begins with an investigation of the effects of the electric field inhomogeneities near wire mesh grids on the resolving power and the ion transmission in TOFMS. The results show that under special conditions, the resolving power and the ion transmission of the instrument can be limited by grid effects. During this analysis, a computer program was developed to model the ion peak shape generated by the time-of-flight mass spectrometer. The peak shape program was incorporated into an existing simplex optimization routine that optimizes the design of a TOFMS system without artificially setting any instrument parameters. The program is valuable for the design and testing of TOFMS systems. This section also contains an analysis of the effects of ion initial conditions on the mass calibration and mass accuracy in time-of-flight mass spectrometry. The results show that a third-order fit to the calibration data will improve the mass accuracy over a wider range of ion masses. The second section of the thesis focuses on understanding the desorption and ionization processes acting during matrix-assisted laser desorption/ionization. Evidence is presented that suggests that the photodecomposition of the matrix leads to the release of analyte molecules and the formation of a supersonic expansion. Data is presented that shows the alkali metal cationization of large molecules occurs by either an ion-molecule reaction or a molecule-molecule reaction takes place in the expanding matrix plume. The data show that the first step in the cationization process is the photodecomposition of the matrix salt to produce a low kinetic energy bare-cation that reacts in the expanding matrix plume. The understanding of these processes has led to the development of new matrix compounds with special properties and analytical applications, as well as a better understanding of the initial conditions of ion formation necessary for the improvement in MALDI instrumentation and the MALDI technique.
Interactions of opioid and chemokine receptor systems
Authors:   , Patel Jeegar P. , Meucci Olimpia
Published: July 2024

A substantial proportion of the HIV-1 infected individuals are intravenous drug users, many of which abuse opiates (Donahoe and Vlahov, 1998). It has been postulated that opiate abuse promotes HIV-1 infection and disease progression, and that opioids can modulate the immune system (Donahoe and Vlahov, 1998; Peterson et al., 1998). Human immunodeficiency virus-1 (HIV-1) can induce a syndrome of cognitive and motor dysfunction that affects about 30% of untreated patients and about 10% of patients treated with antiretrovirals (Dore et al., 1999; Major et al., 2000; Sacktor et al., 2001; Sacktor et al., 2002). This syndrome has been designated HIV-1 associated dementia (HAD) and is due to neuronal loss and dysfunction in various regions of the brain (Price et al., 1988; Masliah et al., 1992). One mechanism of HIV-1 induced cell death and dysfunction is thought to occur via the HIV viral protein gp120. The gp120-mediated cell death occurs through chemokine receptors present on both neuronal and glial cells. The gp120 neurotoxicity appears to be caused by apoptotic signaling cascades initiated by binding of gp120 to chemokine receptors expressed on the surface of neurons and glia (Meucci et al., 1998; Kaul and Lipton, 1999; Meucci et al., 2000). Recent data from various labs have shown a direct interaction of opioids and their receptors with the HIV co-receptors CXCR4 and CCR5 on immune cells (Hu et al., 2000; Mahajan et al., 2002; Steele et al., 2003; Szabo et al., 2003). Furthermore, epidemiology studies indicate that opiates may enhance HIV neuropathology. This proposal sets out to explore the interactions between the [mu]-opioid and CXCR4 chemokine receptor systems in neuronal cells, both at the receptor level and the subsequent signaling pathways associated with each in the context of HIV associated dementia. Our hypothesis is that [mu]-opioid agonists modulate CXCR4 chemokine receptor activation and thus may alter the chemokine-induced cell signaling events, which play a role in neuronal survival. The data will provide insight into the interaction of the two distinct receptor systems and allow for a better understanding of the increased progression of HAD in opioid users.
The role of inflammatory mediator cells in the pathogenesis of colitis in experimental animal models
Authors:   , Flanigan Anne , Tuszynski George P.
Published: July 2024

The underlying feature of inflammatory bowel diseases, Crohn's disease and ulcerative colitis, is the influx of inflammatory cells. These cells include neutrophils and lymphocytes, which have been implicated in tissue damage. These studies investigated the role of neutrophils and T-lymphocytes in colitis. Acute colitis was induced by giving mice 4% DSS in their drinking water. First, Interleukin-8 (a potent chemoattractant) was given to mice with DSS-induced colitis to increase the influx of neutrophils. In a separate study, mice were given DSS-induced colitis with a CXCR2 (neutrophil chemoattractant receptor) antagonist (S13265610) to decrease neutrophil influx. The immune complex model of rabbit colitis was also used for the CXCR2 studies because this model produces a primarily neutrophil driven disease. Second, SCID and RAG2 (T and B-cell deficient) mice on a Balb/c and 129SvEv background were given DSS-induced colitis. In addition, SCID mice were adoptively transferred with a pro-inflammatory subset of T-cells (CD45RBhigh cells) and then given DSS-induced colitis 2 or 4 weeks later. Results of these studies showed that IL-8 caused a significant increase in disease severity. Administration of the CXCR2 antagonist led to a significant decrease in disease severity in both mice and rabbits. SCID and RAG2 mice had significantly less disease than their immune-intact controls. RAG2 mice on a 129SvEv background had significantly less disease than RAG2 on a Balb/c background even though there was no difference between the Balb/c and 129SvEv control mice. RAG2 mice had significantly less disease than SCID mice. SCID mice that were adoptively transferred with CD45RBhigh T-cells and given DSS-induced colitis 4 weeks later, demonstrated a higher disease than the other groups. It can be concluded that neutrophils and T-lymphocytes play an essential role in the pathogenesis of colitis in the experimental animal models utilized here. CD45RBhigh T-cells exhibit their pro-inflammatory effect in the DSS model. In addition, this study demonstrates a difference in genetic susceptibility to DSS-induced colitis. Finally, this work represents a significant finding of a therapeutic potential use of CXCR2 antagonists in the treatment of human IBD.
The acute effects of antipsychotic medications on schizophrenics' health
Authors:   , Delgado Bonnie J.
Published: July 2024

The purpose of this study was to compare the health of schizophrenic patients administered Clozaril, Risperdal or Haldol as their primary antipsychotic medication over a three-year period. In order to be included in this study, participants had to be consistently treated with Clozaril, Risperdal or Haldol for at least 12 months. Participants' health was specifically focused on weight gain and the development of diseases. Health was also indexed by participants' temperature, blood pressure, respiration and pulse. The data was collected using archival medical and psychological records from Norristown State Hospital. There were 119 participants with a mean age of 43 years (SD = 12.9). The participants' gender was 36% females (43) and 64% males (76). There were no differences among schizophrenic participants administered Clozaril, Risperdal or Haldol in the amount of weight gained or the development of diseases. During the course of the study, all participants evidenced weight gain and the development of endocrine diseases. In addition, fifty percent of the participants had at least one of the following diseases or medical problems: hypertension, hypothyroidism, anemia, extrapyramidal symptoms, chronic obstructive pulmonary disease, diabetes, cataracts, an electrolyte imbalance, seizure disorder, hyperprolactinemia and hepatitis C.
Molecular membrane interactions of cortisol and 17[beta]-estradiol
Authors:   , Golden Gil Adam , Mason R. Preston , Rubin Robert T.
Published: July 2024

There is strong evidence to support the hypothesis that many rapid cellular effects of steroids are membrane-mediated, including the demonstration of rapid steroid actions in the absence of intracellular receptors, in the presence of RNA or protein synthesis inhibitors, and in response to steroids coupled to large proteins that prevent intracellular access. However, the basic mechanisms responsible for mediating the membrane effects of steroids are not well understood. This dissertation examines the basic biochemical and physical interactions of steroid hormones with biomembranes to gain new insight into the mechanism(s) involved in rapid steroid actions. It has been hypothesized that steroid hormones, like cholesterol, intercalate into the membrane bilayer and indirectly modulate integral membrane protein activity by perturbing certain physical characteristics of the lipid matrix. This hypothesis was tested by selecting two naturally occurring steroids, a glucocorticoid (cortisol) and a sex steroid (17[beta]-estradiol), and using them to (1) measure steroid partitioning into model cell membranes, (2) determine the effect of membrane-composition on steroid partititioning, (3) identify the energetically-favorable membrane binding locations of steroids and their effects on membrane structure, and (4) measure rapid steroid effects on a human integral membrane protein (Na?, K?-ATPase). At physiological conditions, these steroids intercalated rapidly to distinct regions of the membrane bilayer and exhibited high membrane-based paritition coefficients. In the membrane, these steroids altered important biophysical and functional properties, as assessed by small angle x-ray diffraction and ion flux measurements. These data suggest that steroid-membrane interactions are highly sensitive to both hormonal stereochemistry and membrane lipid composition, and that rapid steroid effects may occur in the absence of direct steroid-protein interactions; thereby contributing to our understanding of the rapid cellular effects of steroid hormones.
The role of CD40 in dendritic cell induced CD8⁺ T cell responses
Authors:   , Kim Alfred Hyoungju , Katsikis Peter D
Published: July 2024

CD8⁺ T cells are important for controlling intracellular pathogens and tumors through death of the target cell. Dendritic cells (DCs) are critical for the elicitation of CD8⁺ T cell responses. However, the factors that regulate DC immunostimulatory capacity are largely unknown. Here, we show that the elicitation of CD8⁺ T cell effector function is controlled by CD40 stimulation of DCs. By immunizing mice with bone marrow-derived DCs infected with live influenza virus, we show that the ligation of CD40 with CD40L trimer in vitro enhances effector differentiation of flu-specific CTLs in vivo. This does not occur with lipopolysaccharide, another classical activator of DC. Using CD40 -/- DCs, we also show that CD40 is required for the generation of these effector cells. Since this effect of CD40 could not be attributed to enhanced DC migration or upregulation of classical activation molecules, we performed gene expression microarray analysis, identifying 78 out of the 13,345 murine genes and ESTs that were uniquely and significantly regulated by CD40 stimulation, including known modulators of CD8⁺ T cell activation such as 4-1BBL, CD27L (CD70), IL-23 p19 subunit, and IL-15R [alpha] subunit. Finally, we tested whether the enhanced generation of effectors induced by CD40 stimulation of DCs during the primary response is accompanied by enhanced memory generation. We detected no differences in the CD8⁺ T cell memory response with respect to clonal expansion and effector generation between mice immunized with unstimulated, LPS-stimulated, and CD40-stimulated flu-infected DCs. However, wild-type mice immunized with CD40-/- flu-infected DCs had reduced absolute numbers of secondary flu-specific CTLs, and similarly, CD40-/- mice immunized with wild-type flu-infected DCs demonstrated deficiencies in CD8⁺ T cell recall responses to influenza. In conclusion, these data demonstrate that CD40 signaling on both the DC and presumably the CD8⁺ T cell is required for generating antiviral recall responses, while CD40 signaling on the DC is critical for mounting primary antiviral effector responses.
Motor control of a functional reaching task in children with cerebral palsy and children with typical development
Authors:   , Zaino Christopher Alan , Westcott Sarah L
Published: July 2024

Many children with cerebral palsy (CP) have underlying impairments in postural control. The evaluation of these impairments includes both laboratory types of measures (kinetic and electromyographic [EMG]) and clinical measures of functional balance and mobility. The reliability of the laboratory measures has not been evaluated in children or during functional tasks. The purposes of the present study are to: (1) evaluate the reliability of kinetic and EMG measurements during a functional reaching task, (2) compare kinetic and EMG measures with clinical measures of functional balance and mobility, and (3) compare and contrast children with CP to children with typical development (TD). While standing on a force plate, an internally generated postural perturbation was given by having the children reach forward to touch a target placed 120% of their arm's length away. The EMG data were categorized into nine consolidated motor coordination patterns (cMCPs) based on the sequence of muscle activations. The clinical measures used were: the Timed Up and Down Stairs, the Timed Up and Go, the Functional Reach Test and the Timed One Legged Stance. The major findings of the study were good test-retest reliability of kinetic measures and poor test-retest reliability of cMCPs. The association between kinetic measures and clinical measures of mobility were mainly moderate. Consolidated MCPs during the late retest trials were shown to have moderate correlations with the Timed Up and Down stairs, Timed Up and Go and Timed One Legged stance (Spearman rank correlations of 0.57, 0.59 and -0.56 respectively). Consolidated MCPs were not significantly correlated with the functional reach test. Because the cMCP test-retest reliability was low, there is little assurance that these correlations were not due to chance. Between group differences were shown for the cMCPs used, the first postural muscle used (increased variability in children with CP) and anticipatory postural muscle activity (decreased in children with CP). The children with TD demonstrated correlations between the mode of the rank ordered cMCPs and anterior-posterior kinetic measures. The children with CP demonstrated an association between the mode of the rank ordered cMCPs and medial-lateral COP measures. Overall, it appears that these two groups of children may be using different mechanisms to maintain postural control during a standing reach task. In addition, kinetic and EMG measures provide different perspectives of the motor control of posture. (Abstract shortened by UMI.).
Expression and modulation of asthma-related cytokines by human lung mast cells
Authors:   , Glaum Mark Christian , Schulman Edward S
Published: July 2024

The human lung mast cell (HLMC) initiates the early phase response (EPR) seen in asthma and is implicated in diverse fibrotic reactions. We hypothesized that HLMC also release cytokines critical to the genesis of the asthmatic late phase response (LPR) as well as asthmatic fibrotic remodeling. We further hypothesized that corticosteroids (CS), the most potent inhibitors of the LPR clinically, inhibited HLMC generation of Th2 cytokines. Either human lung fragments or HLMCs (>90% pure) were incubated for 16 hr at 37° C in media with or without the corticosteroid dexamethasone (Dex, 1 [mu]M). Fragments or cells were washed, then challenged with buffer, the immunologic stimulus anti-IgE (3 [mu]g/ml) or the non-immunologic stimuli phorbol 12-myristate 13-acetate (PMA, 50 ng/ml) or ionophore A23187 (ION, 1 [mu]g/ml). Histamine release was measured at 20 minutes post-challenge. At 2-4 hr post-challenge, mRNA was analyzed by either RNase protection assay (lung fragments) or RT-PCR (cells) using probes/primers for the Th2 cytokines IL-5, IL-13, IL-16 and the fibrogenic cytokine TGF-[beta]. In either lung fragments or HLMC, Dex preincubation abrogated the anti-IgE-induced expression of IL-5 mRNA and IL-13 mRNA and in HLMC, attenuated expression of IL-16. Anti-IgE-challenged HLMC showed little increase in TGF-[beta] mRNA expression, while PMA-challenged cells showed a 10-fold increase. Preincubation of HLMC in Dex failed to influence constitutive expression of TGF-[beta] mRNA. HLMC showed positive intracellular staining for TGF-[beta] and ELISA experiments demonstrated a 110% (+/- 18%) increase in PMA-induced protein release. We conclude that Dex exerts differential effects on HLMC mediator generation. Since Dex inhibits HLMC-derived Th2-type cytokines (LPR mediators) but not histamine release (EPR mediator) or constitutive TGF-[beta] expression, CS may clinically inhibit the LPR, but not the EPR or fibrotic reactions. Efforts to understand culpable mast cell-derived late phase mediators, as well as mechanisms by which steroids differentially modulate HLMC mediators will provide insight into asthma pathogenesis and better understanding of treatment modalities for this disease.