bluuebunny/crossref_metadata_2025 huggingface dataset:
A Snapshot in Time: Consumer Behavior at the Start of COVID-19
Authors: Childs Michelle L. , Sneed Christopher , Berry Ann A. , Ha Sejin
Published: December 2023

During the early stages of the coronavirus pandemic,
consumers faced challenges related to obtaining household items due to shortages and
limitations in shopping. Researchers from the University of Tennessee conducted a
national, web-based consumer survey of 300 consumers in late April 2020 to better
understand consumer behavior, shopping patterns, and demand shifts for goods and
services. Major findings demonstrate that consumers have increased shopping for
essential products from brick-and-mortar national chains, avoided brick-and-mortar small
businesses, and have chosen to shop more by themselves, often choosing to forgo spending
from across all product categories, compared to prior to the pandemic. Additionally,
results indicate that lower levels of positive emotions and active resilience are
responsible for higher levels of shopping frequency. Additionally, lower levels of
passive resilience and optimism are associated with increases in co-shopping behaviors.
Findings from this study provide insight into the changes among consumers during trying
times and the influence of consumers’ emotions and individual characteristics in helping
to explain these changes in family resource management and mental health, as well as
consumer resilience amidst changing macroeconomic conditions.
Association between Hemorrhagic Stroke and Diabetes Mellitus; A Hospital-Based Case-Control Study
Authors: Tawhid Mohammad Homayun , Habib Khatera
Published: December 2023

Introduction: Stroke is the third leading cause of death in the world. Numerous studies show that diabetes mellitus is one of the risk factors for stroke. In general, stroke is divided into two types: hemorrhagic & ischemic, and approximately 15-25% of strokes are the hemorrhagic type. 

Objective: As it is claimed that diabetes mellitus is an important risk factor for hemorrhagic stroke, this study attempts to explain the association between diabetes and hemorrhagic stroke.

Method and Data Collection: According to Epi Info statistic software; 102 participants who were 40≥ years old, and had a hemorrhagic stroke in their brain CT scan or MRI, were selected as cases, and 255 Participants without having a hemorrhagic stroke, including as controls. The proportional distribution of cases and controls in terms of sex and age was considered. Data has been obtained primarily through the design of a questionnaire from admitted patients in the neurosurgery and neurology wards of Aliabad university hospital. 

Results: Out of 357 participants, 181 (50.7%) participants were female and 176 (49.3%) were male. The study found that 25.5% of the participants in the case group, and 13.3% of the participants in the control group, were exposed to diabetes mellitus. 

 Considering (P-Value = 0.006) and Odds ratio (OR=2.224; 95% CI = 1.253 – 3.945), the association between hemorrhagic Stroke and diabetes mellitus is suggested to be significant.

Conclusion: As a result of the study, we can claim that among other risk factors, Diabetes Mellitus can also be considered a possible predisposing factor for Hemorrhagic Stroke and there is a significant association between Hemorrhagic stroke and Diabetes mellitus.
Morphological Variation in Achenes in Certain Species Belonging to the Tribe Cardueae (Asteraceae) in Iraq
Authors: Abd Ayman Adwan
Published: December 2023

This study investigated the morphological attributes of achenes among nine species within the Cardueae tribe of the Asteraceae family in Iraq. The specimen collection occurred between March 2021 and July 2022. Dissecting microscopy was used to document twelve morphological characteristics. Among the traits that were evaluated, it was found that achene size, symmetry, hilum location, the achene apex, and the existence or lack of the pappus were crucial diagnostic markers for identifying the species. The results demonstrate the significance of several achene traits, including color, size, and hilum, in recognizing and separating the studied species. Furthermore, the shape of the achene assisted in distinguishing Notobasis syriaca from the different species under investigation. The prognosis of the species was significantly influenced by the color and the outer and inner pappus lengths. The achene apex shape was crucial in dividing the studied species into two groups: denticulate and entire.
Interplay Between Social Harm and Education: Toward Preventing Societal Detriment
Authors: Moqimi Moahmmad Basir
Published: December 2023

The Interplay Between Social Harm and Education: Toward Preventing Societal Damages seeks the complex relationship between each other, by supporting the role of education in preventing and reducing societal problems. Social harm includes a wide vision of behaviors and conditions that cause harm to individuals, communities, and as well as to societies. It could manifest in various forms, such as violence, mental health issues, crime, substance abuse, and social exclusion. Or in a simple term, those actions which are considered both illegal and morally disgraceful in society. Education centers help as powerful tools for addressing social harm by developing personal growth, promoting social unity, and empowering individuals to make positive choices, and if we look into the triangle of home, educational institutions, and society as a fundamental component of the teaching and learning process we will discover a dynamic interplay between these three realms that shapes and boosts individual growth and collective knowledge. This study searches through the key and considerably discussed realm of social harm within the disciplines of sociology and education, with a particular focus on the interplay between these two domains. Central to these discussions are inquiries into the meaning and the nature of social harms, the educational objectives aimed at reducing social harm, and the principles, methodologies, as well as educational approaches employed in reducing these societal problems.
Modern Georgian corporate law in the mirror of European law. General review of the reform
Authors: Burduli Irakli
Published: December 2023

One of the obligations under the Georgia-EU Association Agreement was to undertake reforms of Georgian corporate law. Since 1 January 2022, Georgia has had a new corporate law, which is built on a regulatory function. From the point of view of law policy, it is based upon the regime of dispositional arrangement, though regulation of joint-stock companies constitutes an exception. Saturation of modern Georgian corporate law with legislative norms is the best way to overcome corporate impasses. As a result of the recent reform, the new corporate law contributes to the foreseeability and predictability of the corporate-legal relationships, which at once should provide more confidence for both foreign and domestic investors. The norms contained in the present reform are also equipped with a didactic function, which is especially necessary for the post-Soviet corporate economy.
La perspectiva diacrónica de los derechos fundamentales y su aplicación en materia de justicia climática
Authors: Alandí López Gisela
Published: December 2023

El presente estudio ha sido elaborado a partir de los resultados obtenidos en mi trabajo de final de grado, La perspectiva diacrónica de los derechos fundamentales, dirigido por el catedrático de Derecho Administrativo y ex letrado del Tribunal Constitucional Carlos Padrós Reig. El artículo aborda la innovadora doctrina de la perspectiva diacrónica o intertemporal de los derechos y las libertades fundamentales, surgida en relación con las obligaciones estatales de protección de los derechos de las generaciones futuras en el marco de la gestión del peligroso cambio climático antropogénico, la cual observa los riesgos de lesiones de los derechos futuros. Así pues, por medio del estudio de las nuevas resoluciones de derecho comparado sobre el cambio climático (con la destacable aportación del Tribunal Constitucional de Alemania en el caso Klimaschutz), se pretende aportar un concepto de protección de los derechos fundamentales que responda a las exigencias de la actual sociedad, en continuo desarrollo, y posibilite su protección intergeneracional, en especial en los supuestos de litigiosidad climática.
Masdéu i Termens, R.: La demografia catalana (segle XVI-1936) (Barcelona, 2021)
Authors: Millàs i Castellví Carles
Published: December 2023

Ressenya de:
Masdéu i Térmens, Raimon (2021)
La demografia catalana (segle XVI-1936)
Barcelona: Rafael Dalmau, Editor, 247 p.
ISBN 978-84-232-0876-0
Pascal, B.: Pensament i opuscles (P. Lluís Font, ed.; Barcelona, 2021)
Authors: Fernández Terricabras Ignasi
Published: December 2023

Reseña de:
Pascal, Blaise (2021)
Pensament i opuscles
Traducció i edició a cura de P. Lluís Font. Barcelona: Adesiara, 2021, 791 p.
ISBN 978-84-16948-74-1
¿Más Ayacucho que Trocadero? La sorprendente vía historiográfica americanista para comprender globalmente un largo bicentenario "Trienista"
Authors: Silva Guijarro Víctor H.
Published: December 2023

La conmemoración del bicentenario del Trienio Liberal en 2020 fue la chispa revolucionaria que provocó el estallido en ambos hemisferios de una eclosión historiográfica sobre este período. Desde un primer instante, los historiadores e historiadoras especialistas en el segundo período constitucional se lanzaron a organizar congresos, publicar libros, dosieres de revistas y un largo etcétera. Todo iba bien hasta que en marzo 2020 la pandemia paralizó la conmemoración. A pesar de la gravedad de las noticias, pero gracias a la incansable labor de los y las especialistas durante la llamada nueva normalidad, esa eclosión historiográfica del Trienio resurgió como un potente haz de luz para cumplir con varios objetivos: superar los estigmas de la historiografía franquista y la tesis del fracaso que predominó durante los años de la Transición y abordar el análisis de la revolución liberal de 1820 como una historia compartida juntando de forma definitiva los procesos revolucionarios de España y América. Por esta razón, en este trabajo se busca realizar un embrionario estado de la cuestión sobre esta eclosión historiográfica del Trienio Liberal que estalló en el marco de su conmemoración en 2020.
Social Media Use and Digital Competence as Predictors of Students' Familiarity with MOOCs
Authors: Stojanov Ana , Daniel Ben , Kenig Nikolina , Hoskins Nadine
Published: December 2023

Massive Open Online Courses (MOOCs) have been disruptive advancements in online learning and teaching in the last decade. We argue that discourses on the value and limitations of MOOCs have largely taken for granted that students are aware of the existence of MOOCs. In the current research, we examined students' awareness of MOOCs and explored digital competence as a potential predictor of such awareness, hypothesising that the effect may be exerted via social media application use. We deployed a questionnaire (Study 1: N = 152, Study 2: N = 158) to measure students' levels of digital competence, their use of social media applications, and their awareness of MOOCs. We also examined students' motivations for enrolling or not enrolling in MOOCs. The results supported our hypothesis that low digital competence is a predictor of low MOOC awareness, but the results from the mediation analysis were not conclusive.
Keywords: digital competence, higher education, MOOC, MOOC awareness, motivation, self-efficacy, social media, social media use benefits, students
Utilisation des médias sociaux et compétence numérique comme facteurs prédictifs de la familiarité des étudiants avec les MOOCs
Résumé : Les cours en ligne ouverts et massifs (MOOC) ont constitué une avancée majeure dans l'apprentissage et l'enseignement en ligne au cours de la dernière décennie. Nous avançons l’idée que les discours sur la pertinence et les limites des MOOC ont largement pris pour acquis le fait que les étudiants étaient au courant de l'existence des MOOC. Dans la présente recherche, nous avons examiné la sensibilisation des étudiants aux MOOC et exploré la compétence numérique en tant que prédicteur potentiel de cette sensibilisation, en émettant l'hypothèse que l'effet peut être exercé par l'utilisation d'applications de médias sociaux. Nous avons diffusé un questionnaire (étude 1 N = 152, étude 2 N = 158) pour mesurer les niveaux de compétence numérique des étudiants, leur utilisation des applications de médias sociaux et leur connaissance des MOOC. Nous avons également examiné les motivations des étudiants pour s'inscrire ou non à des MOOC. Les résultats confirment notre hypothèse selon laquelle une faible compétence numérique est un facteur prédictif d'une faible connaissance des MOOC, mais les résultats de l'analyse de médiation ne sont pas concluants.
Mots-clés : compétence numérique, enseignement supérieur, MOOC, connaissance des MOOC, motivation, auto-efficacité, médias sociaux, avantages de l'utilisation des médias sociaux, étudiants
Beauty is Truth, Truth Beauty: Students’ Assessment of Credibility in Online Materials
Authors: St Clair Ralf , Shirdel Pour Maryam , Nahachewsky James
Published: December 2023

This study discusses the findings of a survey designed to capture students’ allocations of credibility to online materials resembling social media posts. The survey respondents were 1,019 undergraduate students at a medium-sized Canadian university. The students came from a range of programs and years of study in those programs. The survey instrument presented varying stimuli to students to see how their scores varied, and then asked students to explain their scoring. A number of significant dynamics emerged, such as the students’ tendency to give lower credibility scores to poorly presented information, even if the information was factual, and to explain information by referring to previous knowledge. These dynamics varied little by area or year of study, which suggests that presentation should be recognized as a powerful heuristic in online credibility assessment.
Keywords: credibility, social media, undergraduate, survey research
La beauté est la vérité , la vérité est la beauté : L'évaluation par les étudiants de la crédibilité des documents en ligne
Résumé : Cette étude présente les résultats d'une enquête visant à déterminer la crédibilité que les étudiants accordent aux documents en ligne ressemblant à des messages de médias sociaux. Les répondants à l'enquête étaient 1 019 étudiants de premier cycle d'une université canadienne de taille moyenne. Les étudiants provenaient d'un éventail de programmes et de différentes années d'études dans ces programmes. L'instrument d'enquête présentait différents stimuli aux étudiants afin de voir comment leurs scores variaient, et demandait ensuite aux étudiants d'expliquer leur notation. Un certain nombre de dynamiques significatives sont apparues, telles que la tendance des étudiants à accorder des scores de crédibilité plus faibles aux informations mal présentées, même lorsqu'elles sont factuelles, et à expliquer les informations en se référant à des connaissances antérieures. Ces dynamiques varient peu en fonction du domaine ou de l'année d'étude, ce qui suggère que la présentation devrait être reconnue comme une heuristique puissante dans l'évaluation de la crédibilité en ligne.
Mots-clés : crédibilité, médias sociaux, premier cycle universitaire, enquête de recherche
Nuclear and Joint Family System: Youth Perspective in Quetta, Balochistan
Authors: Jamil Zakia , Kakar Rubina , Habib Safia , Sultan Rana Saba
Published: December 2023

Every human being is a part of either a joint family or a nuclear family. Both types of families have multiple positive and negative consequences on individuals' lives, as previous literature represented various advantages and disadvantages of joint and nuclear families. According to Khatoon, A. (2008), in a joint family, the children's self-decision is discouraged due to the dominancy of the family head in all their choices. The aim of the present study was to analyze the actual experiences and perceptions of youth regarding joint and nuclear families in Quetta City. Even though the existence of joint and nuclear families has a strong influence on individuals' lives, there is still no scholarly work on them. Henceforth, the study selected a qualitative approach to analyze the experiences of youth (B.S. students) from the University of Balochistan. One Focus Group Discussion(FGDs) and nine interviews were conducted on the basis of data saturation through convenient sampling. Data collection tools included interview guide schedules in order to obtain rich pieces of information for targeted phenomena. Further data was analyzed through a thematic analysis tool. However, the findings of the present study portrayed the experiences and perceptions of respondents belonging to both family systems.
Controversial Portrayal of Women in Pashto Proverbs
Authors: Ullah Ihsan , Ullah Shakir , Rahim Noor Ur
Published: December 2023

This research aims to explore the controversial representation of women in Pashto proverbs. It delves into the cultural significance of these proverbs and their impact on gender roles and perceptions. Through a deep analysis of a distinct set of Pashto proverbs, this study explores the common stereotypes, biases, and gender-based discrimination fixed in these linguistic expressions. It also investigates the evolving dynamics of women's roles in Pashto society and the potential consequences of these proverbs on contemporary gender relations. The data was collected in Pashtun society, and elders were joined for this purpose. The study's findings showed that these proverbs portray women as weak and dependent, with men as their masters. The negative portrayal of women in Pashto proverbs affects their social and economic status.
Desarrollo del pensamiento crítico en estudiantes de Ingeniería mediante una estrategia didáctica que integra laboratorios remotos sobre circuitos eléctricos: primera intervención
Authors: Guerrero Zambrano Marcos , Concari Sonia Beatriz
Published: December 2023

The objective of this research is to evaluate the effect of a didactic strategy that integrates remote laboratory practices on the subject of electrical circuits to promote the development of critical thinking in engineering students from a state university in Ecuador. It is design-based research that combines both quantitative and qualitative methodologies divided into two interventions; here we present the first intervention in which a teacher and 60 subjects between 18 and 20 years of age participated. The design of the didactic strategy included readings, open and closed questions and carrying out experimental practices with a remote laboratory. Two tests were applied to determine the levels of development of critical thinking and the level of learning achievement of the studied subjects: at the beginning, prior to the design and application of the strategy, as a diagnostic evaluation and at the end, after applying the didactic strategy. Comparing the results of both tests at the beginning and at the end of the application of the didactic strategy, it was found that 33 subjects increased their level of critical thinking by at least 1 point, a result validated with the Wilcoxon test, and 38 subjects increased their level of learning achievement by at least 1 point, a result validated through the Hake gain, which corresponds to 61 % and 63 % respectively of the total sample. As a result of the application of the didactic strategy, of the 60 subjects in the sample, 23 (38 %) significantly improved both the development of critical thinking and learning.
Estrategia didáctica para identificar y modelar conceptos básicos de mecánica basada en los estándares científicos de la próxima generación
Authors: Hernández Yano José Wiliulfo , Ramírez Díaz Mario Humberto , Dávila Carmona Barbarela
Published: December 2023

This paper describes a group of first-semester students entering the Mechanical Engineering program at the Universidad Autónoma de Tlaxcala in Mexico. The paper identifies several didactic strategies aligned with a distance course and the Next Generation Scientific Standards reference framework. Furthermore, the paper incorporates modeling of basic concepts and reflective thinking as part of the transversal concept. The proposed strategy is to lead students to the basic modeling of the fundamental concepts of Newtonian mechanics, so that they recognize the system of physical principles and concepts that are associated with Newton's three laws of motion. The strategy begins by showing real-world phenomena or experiments through short videos, for the construction of pictorial representations that are typical of science and technology. In parallel to the class, students work on a project that is linked to the previous concepts as they advance in their development. The results indicate that the students were able to anchor some real-world phenomena with important concepts through models, although they still have some semantic problems.
Radiação eletromagnética aplicada à conservação de alimentos
Authors: Gomes Vaz Andreia , Samudio Pérez Carlos Ariel , Werner da Rosa Cleci Teresinha , Prado Rogério
Published: December 2023

This article was produced based on the results of the application of a didactic proposal with the objective of providing educators with a teaching tool that contributes to the acquisition of contextualized scientific knowledge, based on innovative techniques and connected with the student's reality. The subject of study was restricted to electromagnetic waves, a subject sometimes approached superficially and decontextualized in high school. To contribute to learning, we developed a didactic sequence based on the theory of meaningful learning by David Paul Ausubel to be applied in five classes in a third-grade high school class. The activities were organized to contemplate different teaching strategies, valuing the diversity in each one's learning. Thus, we developed expository activities, lectures, directed study and even the construction of an experimental prototype, valuing cooperative work and student protagonism. The experiment aimed to work, in particular, the ultraviolet radiation applied to food conservation, seeking to signify the physical concepts addressed. The work made it possible to verify in locu that the possibility of handling, cooperating and building knowledge through methodologies that allow a greater involvement of students on the subject under study can result in learning with greater meaning.
Extractive optimization of antioxidants and phenolic compounds from Anacyclus pyrethrum
Authors: CHATER Oumaima , EL GHADRAOUI Lahsen , HARRACH Ahmed , AAZZA Smail
Published: December 2023

Anacyclus pyrethrum (L.) Lag. is a Moroccan endemic species well appreciated as a remedy against toothache, digestive disorders, and as a tonic agent for the nervous system. This work aims to select the best solvents for extracting antioxidants and optimize their extraction using a surface mixture design. In this study, eleven solvents with different polarities were screened for their efficiency to extract total phenolic compounds and other molecules endowed with antioxidant activity. The antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and total antioxidant activities. The selected solvent was subjected to response surface methodology using a simplex axial mixture design to optimize the extraction of polyphenols and antioxidants. The results showed a significant influence of solvent nature on extraction. Water, ethanol, chloroform, and methanol were the most effective solvents to achieve good polyphenol yields. The best yield is obtained using the tertiary mixture “water-methanol-ethanol”. The anti-radical activity in A. pyrethrum was significantly influenced by the extraction solvent's nature and the mixture's nature. The percentage of inhibition of DPPH was higher in both extracts obtained with the ternary mixture and binary mixtures “water-methanol” and “water-ethanol”. the best total antioxidant capacity was observed for pure water, followed by binary mixtures including water. This study revealed a good synergetic effect between water and both ethanol and methanol on extraction efficiency. Furthermore, the ternary mixture with the following proportions: water 75%; ethanol 11%; methanol 14% was the most efficient.
Evaluation of mosquito larvicidal activity of green synthesized crystalline silver nanoparticles using leave and fruit extracts of Phyllanthus acidus L. (Phyllanthaceae)
Authors: GOPE Arpita , RAWANI Anjali , CHATTERJEE Priyajit
Published: December 2023

The present study evaluates the potentiality of green silver nanoparticles from the leaves and fruit extracts of Phyllanthus acidus L. against third instar larvae of two vector mosquitoes namely Culex quinquefasciatus and Culex vishnui. Various spectroscopic techniques were used to characterize the synthesized silver nanoparticles (AgNPs). Synthesized silver nanoparticles from both the leaf and fruits of P. acidus were spherical to quasi-spherical in shape and showed Surface Plasmon Resonance (SPR) bands at 420 and 409 nm respectively. In larvicidal bioassay with synthesized AgNPs from the leave of P. acidus, 100% mortality was observed at 20 ppm against third instar larvae of both the mosquito species with LC50 values of 1.64 and 0.87 ppm respectively. 100% mortality was observed in 5 ppm concentration against both Cx. quinquefasciatus and Cx. vishnui in synthesized AgNPs from fruits of P. acidus with LC50 values of 1.62 and 1.24 ppm respectively. The above findings suggest that the AgNPs synthesized from P. acidus leaves and fruit extracts have the potential to be employed in vector mosquito population control.
Changing difficulty level in a one-dimensional tracking task and corresponding heart rate changes
Authors: Bohdanecký Zdeněk , Indra Miroslav , Radil Tomáš
Published: December 2023

Subjects were required to track a target consisting of two vertical bars moving with either a constant or a sinusoidally modulated speed across an oscilloscope screen with a joystick-controlled light-spot. Either target size (distance between bars - size guided tasks) or velocity of the target movement (velocity guided tasks), varied throughout different tasks determined by subject's performance. The target's initial movement period was either 2 or 3 seconds. The following parameters were studied: time on-target intervals, time off-target intervals, number of tracking errors, heart rate and tracking error incidence over the cardiac cycle. Time on-target intervals were longer for the velocity guided tasks than for the size guided ones. The same was true for time off-target intervals. Values for both types of intervals decreased gradually over the fixed sequence of tasks for velocity but not for size guided tasks. Heart rate was higher in the size guided task. Tracking error incidence did not depend on the phase of cardiac cycle.
"Tubulofilamentous particles" are not scrapie-specific and are unrelated to tubulovesicular structures
Authors: Liberski Paweł
Published: December 2023

"Tubulofilamentous particles" has been defined as "thick" tubules, apparently distinguishable from other cytoskeletal elements, in touch-preparations from scrapie- and Creutzfeldt-Jakob disease (CJD)-infected brains. I report here that "tubulofilamentous particles" are nonspecific findings unrelated to the subacute spongiform virus encephalopathies (SSVE) as they are observed in brains of control animals. I further suggest that these "tubulofilamentous particles" are unrelated to "tubulovesicular structures" (TVS) which are the only particles consistently observed in brains of naturally occurring and experimentally induced SSVE.
Topography of primary afferent projections in the trigeminal sensory nuclei of rats
Authors: Florence Sherre , Lakshman Shankar
Published: December 2023

The afferent projection pattern from individual vibrissae follicles was related to the distribution of cytochrome oxidase (CO) dark cell clusters in the trigeminal sensory nuclei of adult rats to determine whether segregated primary afferent projections limit the extent of the topographic reorganizations that can occur at the level of the brainstem on a short term basis after changes in sensory driven activity. The results indicate that the projections to all the brain stem trigeminal subnuclei, including the principal sensory nucleus and the three subdivisions of the spinal trigeminal nucleus, are topographic; however, the extent to which label from different whisker rows overlap appears to differ from subdivision to subdivision. In the principal sensory nucleus there is nearly a one to one relationship between the inputs from the vibrissae follicles and the corresponding CO-dense clusters. Thus, little overlap of inputs from different vibrissae rows is likely. In contrast, in the pars interpolaris and, to a lesser extent, in the pars caudalis, inputs from individual vibrissae follicles extend beyond the appropriate CO-dark patch into adjacent whisker patches; thus, inputs to these subdivisions from different vibrissae likely overlap more extensively.
pt point mutation in plp gene results in hyperexpression of MOG in hypomyelinated rabbit
Authors: Sypecka Joanna
Published: December 2023

Myelin/oligodendrocyte glycoprotein (MOG) is a minor myelin protein that belongs to the immunoglobulin gene superfamily and evokes demyelination based on immunological response. Localized preferentially at the external surfaces of myelin sheaths, it is one of the primarily target autoantigens in experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. Elevated MOG content has been found in the myelin fraction of the rabbits affected by the mild form of paralytic tremor (pt) disease, evoked by natural, point mutation in exon 2 of plp gene. A single T --> transversion results in substitution of histidin36 by glutamine in PLP and it's splicing variant DM-20 molecules. The affected animals, although strictly controlled for pt trait, differ significantly in their phenotypes, distinguished by the severity of neurological symptoms. It was shown that the degree of CNS hypomyelination and deficiency of PLP/DM-20 correlates well with the severity of neurological symptoms and is highest in the most strongly affected animals. Variety of phenotypes generated from pt genotype together with previously observed MOG hyperexpression suggested possible contribution of immunological component to the pt disease. Present studies indicate that MOG expression depends both on the phenotype and the age of affected rabbits and most probably mirrors retardation in myelinogenesis process caused by pt mutation.
The effect of prolonged administration of lithium on the level of dopamine D2 receptor mRNA in the rat striatum and nucleus accumbens
Authors: Kostrzewa Richard , Brus Ryszard , Perry K.W. , Fuller R.W.
Published: December 2023

To explore associations of neostriatal (NST) endogenous levels of dopamine (DA) and serotonin (5-HT) with sensitivity of their receptors, graded doses of 6-hydroxydopamine HBr (0 to 400 micrograms, ICV; 6-OHDA; desipramine pretreatment, 20 mg/kg IP) were given to rats between birth (P0) and P42. Numbers of vacuous chewing movements (VCMs) induced by SKF 38393 or m-chlorophenylpiperazine (m-CPP), respective DA D1 and 5-HT2 agonists, were subsequently determined. Enhanced SKF 38393-induced VCMs occurred when NST DA was reduced 97%–98% by high dose 6-OHDA (100–134 micrograms) at P0 or P3, but not in rats with 95%–97% loss in DA produced by 6-OHDA at P7 (134 micrograms) or P3 (67 micrograms), Enhanced m-CPP-induced VCMs occurred even when NST 5-HT content was not elevated after 6-0HDA (134 micrograms at P10). Accordingly, D1 and 5-HT receptor sensitivity is not correlated with respective NST DA and 5-HT contents. The stage of ontogeny at the time of DA denervation may be the governing influence on receptor sensitivity.
Changes of Ca2+/calmodulin - dependent protein kinase-II after transient ischemia in gerbil hippocampus
Authors: Zalewska Teresa , Zabłocka Barbara , Domańska-Janik Krystyna
Published: December 2023

Transient cerebral ischemia induces, besides delayed neurodegeneration in selected brain structures, a number of early responses which may mediate ischemic injury/repair processes. Here we report that 5 min exposure to cerebral ischemia in gerbils induces a rapid inhibition and subsequent translocation of Ca2+/calmodulin-dependent protein kinase II (CaMKII). These changes were partially reversible during a 24 h post-ischemic recovery. Concomitantly the total amount of the enzyme protein, as revealed by Western blotting (alpha-subunit specific), remained stable. This is consistent with our previous hypothesis, that the mechanism of ischemic CaMKII down-regulation involves a reversible posttranslational modification-(auto)phosphorylation, rather than the degradation of enzyme protein. The effectiveness of known modulators of postischemic outcome in counteracting CaMKII inhibition was tested. Three of these drugs, namely dizocilpine (MK-801), N-nitro-L-arginine methyl ester (L-NAME) and gingkolide (BN52021), all significantly attenuated the enzyme response to ischemia, whereas an obvious diversity in the time-course of their actions implicates different mechanisms involved.
The contribution of AT1 and AT2 angiotensin receptors to its cognitive effects
Authors: Braszko Jan
Published: December 2023

In this study I attempted to assess, in rats, the role of AT1 and AT2 angiotensin receptor subtypes in the phenomenon of improved learning and memory after an intracerebroventricular (icv) injection of angiotensin II (Ang II) and Ang II (3–7). Selective AT1 (losartan, 1 mg) or AT2 (CGP 42112 A, 2 micrograms) receptor antagonist was dissolved in 2 micrograms of saline and given to the left cerebral ventricle 5 min before 1 nmol Ang II or Ang II (3–7) injected in the same volume of saline to the right ventricle. Consequently, there were 9 experimental groups which underwent 3 memory oriented and 3 auxiliary tests. Ang II and Ang II (3–7) significantly improved retention of the passive avoidance and recognition memory. These effects were abolished by losartan or CGP 42112 A. Better, after Ang II and Ang II (3–7), acquisition of conditioned avoidance responses was unchanged by losartan and abolished by CGP 42112 A. None of the treatments significantly changed rats motor behaviour in open field. Losartan as well as CGP 42112 A abolished significant enhancement of apomorphine (1 mg/kg, ip) stereotypy caused by Ang II and Ang II (3–7). The results suggest considerable involvement of AT1 and AT2 angiotensin receptors in the cognitive enhancement produced by angiotensins.
Biphasic enhacement of nitric oxide synthase activity and cGMP level following brain ischemia in gerbils
Authors: Strosznajder Joanna , Chalimoniuk Małgorzata
Published: December 2023

This study was aimed to examine properties and changes in nitric oxide synthase (NOS) activity and cGMP level during reperfusion after 5 min of brain ischemia in gerbils. Animals were treated 5 min before ischemia with NOS inhibitors: N-Nitro-L-arginine (NNLA), or 7-Nitroindazole (7-NI), or with the inhibitor of guanylate cyclase, LY 83583, or with hydrocortisone for 7 days before ischemia. Northern blot analysis was performed using specific cDNA for inducible NOS. It was observed that ischemia significantly enhances NOS activity and cGMP level. During reperfusion, biphasic increase in NOS activity and cGMP level took place with two peaks 15 min and 2 h after ischemia. NNLA, 7-NI, and LY 83583 eliminated enhancements of NOS activity and cGMP level, whereas glucocorticoid remained without effect. There was no activation of gene encoding inducible NOS (iNOS). Our results indicate that ischemia-reperfusion activates constitutive NOS. It is suggested that nitric oxide (NO) production during reperfusion is related to neuronal degeneration and that inhibitor of NOS offers a new therapeutical strategies.
Different developmental rates of selected brain structures in humans
Authors: Dąmbska Maria , Kuchna Izabela
Published: December 2023

Various rates of development are characteristic for particular structures of the human central nervous system (CNS). The differences of the maturing brain stern and telencephalon are evident in a routine neuropathological examination. The fetal and postnatal archi- and neocortex also reveals uneven levels of maturation. In order to precisely describe those differences in humans we performed a morphological and morphometric study on the dorsal vagal nucleus of the medulla oblongata, on Ammon's horn and on neocortex from midgestation to the 18th postnatal month. The numerical density of neurones, cell perikarya and nuclear cross-sectional area, and the ratio of nucleus to perikaryon area were measured. The results demonstrate a development-dependent decrease in cell density and progressive differentiation of neurones according to their changing size. They express a process of maturation which differs in rate across the CNS structures examined.
The presence of coherence in sympathetic and phrenic activities in a developing mammal
Authors: Gootman Phyllis , Hundley Bruce , Sica Anthony
Published: December 2023

To determine whether are development changes in the baroreceptor and central respiratory modulation of sympathetic activity, we used ordinary and partial coherence spectral analyses on cervical and splanchnic sympathetic activity in swine 1–36 days old. Removal of baroreceptor influences from cervical sympathetic and splanchnic spectra using partialization shows that 3–6 Hz peaks are due to baroreceptors since coherence decreased in > 19 days old while remaining unchanged in
The rhythmic slow activity recorded from entorhinal cortex in freely moving cats
Authors: Błaszczyk Marcin , Grabowski Robert , Eckersdorf Barbara , Gołębiewski Henryk , Konopacki Jan
Published: December 2023

The relationships between the entorhinal cortex (EC) and the hippocampal formation (Hipp) field potentials were examined in the present study. The detailed analyses of the signal let us group the patterns of theta appearance into three categories: (1) Theta rhythm dominating in both recordings from the EC and from the Hipp (2) Theta rhythm dominating in the Hipp with irregular activity in the EC (3) Theta rhythm dominating in the EC with irregular activity in the Hipp. These findings provide the evidence for the intrinsic generator of theta rhythm to be localized in entorhinal cortex in cats.
Beyond mapping: estimating complexity of multichannel EEG recordings
Authors: Wackermann Jiří
Published: December 2023

A new measure of complexity of multichannel EEG recordings is proposed. The quantity assesses the diversity of activities of different brain generators contributing to the global dynamics of electric field of brain.
The evoked cardiac response as a function of cognitive load in subjects differing on the individual difference variable of reaction time
Authors: Kaiser Jan , Beauvale Andrzej , Bener Jarosław
Published: December 2023

We report research on different phasic evoked cardiac responses associated with differences in cognitive activity. These were examined in relation to a stable individual difference variable, mean simple reaction time (RT). Individual means on RT were found to be sufficiently stable over a 10 month period to consider them as individual functional characteristics. Subjects were divided into two subgroups on the basis of the first measure of their individual mean RT (above and below the group median). Each subject received 10 innocuous auditory stimuli with randomly varying interstimulus intervals. Stimuli were presented in one of two conditions defined by instructions allowing them to ignore (irrelevant condition), or requiring them to count the stimuli (relevant condition). A main effect of instruction was obtained in the evoked cardiac response. The initial heart rate deceleration was significantly larger in the irrelevant condition and a later acceleration was significantly larger in the relevant condition. Short-RT subjects had smaller heart rate changes to the irrelevant stimuli. The data are discussed in terms of the intensity of stimulus processing (both physical and cognitive) as a factor which may be related fundamentally to stable individual differences in RT.
Influence of CCK-8 and yohimbine on supraspinal modulation of nociceptive process
Authors: Szymbor Bożena , Kowalczyk Marek
Published: December 2023

We studied the effect of cholecystokinin (CCK-8) and yohimbine – alpha-2-adrenoreceptor antagonist administered locally into lateral reticular formation (LRF) on the bioelectrical response to the pain stimulation. The experiments were carried out on 8 conscious rabbits with bilaterally implanted electrodes into: motor-sensory cortex, ventro-postero-lateral thalamic nuclei, hippocampus and LRF. Nociceptive stimulation was performed by means of electrical pulses applied to the front paw. Bioelectrical activity (BA) of the chosen brain structures was analysed by means of spectral analysis (FFT) and directed transfer function (DTF). The results of our study may suggest that supraspinal administration of CCK-8 together with yohimbine have inhibitory effect on nociceptive transmission.
Calcium transients in brain ischemia: role in neuronal injury
Authors: Łazarewicz Jerzy
Published: December 2023

The involvement of calcium ions in mechanisms of ischemic brain injury has been suggested for several years. Our understanding of the role of intracellular Ca2+ as a trigger of acute neurotoxicity and in the induction of long lasting processes leading to necrotic and/or apoptotic postischemic delayed neuronal death or of compensatory, neuroprotective mechanisms has increased considerably. Still many questions concerning the generation of Ca2+ signal such as the nature of the main routes of ischemic Ca2+ influx to neurones, involvement of intracellular Ca2+ stores and Ca2+ buffers, spatial and temporal relations between ischemia-induced increases in intracellular Ca2+ concentration and neurotoxicity remain open. Some conclusions from experiments in cultured neurones concerning glutamate-evoked destabilization of Ca2+ homeostasis and neurotoxicity may be not relevant to in vivo ischemic conditions. This review, apart from emphasising generally proposed mechanisms of Ca2+ transients and toxicity in ischemic neurones, will discuss some of these controversial issues.
Monosynaptic Ia pathways and motor behaviour of the cat distal forelimb
Authors: Illert Michael
Published: December 2023

The projection pattern from large muscle spindle afferents (Ia) onto cat alpha-motoneurones innervating the elbow, wrist and digit muscles is correlated with new electromyographical and x-ray kinematic data on the motor behaviour of the forelimb. This correlation suggests that the la-synergistic groups may be one substrate to organize movement components mobilized in motor behaviour. This hypothesis is based on the data on the active stabilization of the radio-ulnar joints during the stance phase, on the data on the la-organization of a motor nucleus taking part in different motor behaviours and on the results showing how the la convergence onto the long digit extensor muscles fits the execution of finely tuned movements at ball joints.
The influence of repeated systemic penicillin injections at subconvulsive doses on spontaneous Spike-Wave Discharges in the rat
Authors: Stankiewicz Jolanta , Gralewicz Sławomir
Published: December 2023

Changes in nonconvulsive spontaneous epileptic activity Spike-Wave Discharges (SWD) – induced by repeated intraperitoneal (i.p.) administration of crystalline penicillin (PC) at subconvulsive doses were evaluated in imp-DAK rats. Three groups received ten daily i.p. injections of PC at doses of 750,000, 500,000 and 250,000 IU/kg b.w. For comparison, another classic convulsant, pentylenetrazol (PTZ) was applied in the same way to another group. PTZ was also given to all rats before and after injection series for better evaluation of changes in CNS excitability. Repeated PC injections resulted in a progressive increase in the basal level of the spontaneous SWD activity and in an increase in the SWD response to PC, which was statistically significant in the case of the dose 750,000 IU/kg. Moreover, in all rats given PC the response to PTZ (increase in SWD activity) was reduced. The results obtained in this and previous experiment suggest that in the course of repeated systemic Pc administration adaptive changes in the rat CNS develop which prevent the convulsive effects of Pc but promote the occurrence of the spontaneous nonconvulsive SWD activity.
Neural systems mediating the negative feedback actions of estradiol and progesterone in the ewe
Authors: Goodman Robert
Published: December 2023

The ewe shows a marked seasonal variation in the effects of ovarian steroids on pulsatile GnRH secretion. In the breeding season, progesterone inhibits GnRH pulse frequency, while estradiol suppresses pulse amplitude. In anestrus, both steroids inhibit pulse frequency. The effects of progesterone in both seasons are mediated by endogenous opioid peptides (EOP) that act in the preoptic area (POA) and medial basal hypothalamus (MBH). However, knife cut studies indicate that actions in the MBH are most important. Moreover, blockade of EOP receptors activates (e.g., induces Fos) GnRH perikarya in the MBH, but not those in the POA. Thus interactions between EOP and GnRH neurons within the MBH may be critical for progesterone negative feedback. The neural systems mediating estradiol suppression of GnRH pulse amplitude in the breeding season are largely unknown, although alpha-adrenergic neurons may be involved. The seasonal variation in inhibition of GnRH pulse frequency by estradiol is postulated to be mediated by a group of dopaminergic (DA) neurons that have three important properties: (1) they inhibit GnRH pulse frequency; (2) their activity is stimulated by estradiol; and (3) they are functional in anestrus, but not the breeding season. Recent work examining the effects of lesions of DA neurons and the ability of estradiol to induce Fos in DA cells strongly suggests that DA neurons in the retrochiasmatic area (A15) and POA (A14) have all three characteristics. We thus propose that these DA neurons are responsible for the seasonal variation in the ability of estradiol to inhibit GnRH pulse frequency.
Antagonism of the discriminative stimulus properties of cocaine with the combination of a dopamine D1 and D2 antagonist
Authors: Meert Theo , Haes Patrick , Aerts Nancy , Clincke Gilbert
Published: December 2023

Antagonism of the discriminative stimulus properties of 10 mg/kg cocaine was studied in rats by use of the dopamine D1 antagonist SCH 23390 and the D2 antagonist haloperidol. Whereas SCH 23390 and haloperidol were by themselves unable' to antagonize the cueing properties of cocaine, the combination of both dopamine antagonists resulted in a complete blockade of the cocaine cue. In the presence of a fixed dose of 0.01 and 0.04 mg/kg haloperidol, the ED 50's (it is the effective dose in 50% of the animals) of SCH 23390 for cocaine antagonism were 0.043 and 0.012 mg/kg, respectively. Similarly, the ED 50's of haloperidol in combination with 0.01 and 0.04 mg/kg SCH 23390 were 0.021 and 0.024 mg/kg. The combined treatment of haloperidol and SCH 23390 resulted in strong response-rate reductions. At all combination regimens resulting in a complete blockade of the cocaine cue, response rate was reduced to less than 20% of the control values. These results indicate that the cueing properties of cocaine are both dopamine D1- and D2-mediated and that a combined antagonism of both receptor subtypes can lead to a complete antagonism of the cueing properties of cocaine which is associated with severe attenuation of response rate.