bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Immediate Early Gene Arc Is Not Required for Hippocampal Long-Term Potentiation
Authors: Kyrke-Smith Madeleine , Volk Lenora J. , Cooke Samuel F. , Bear Mark F. , Huganir Richard L. , Shepherd Jason D. 
Published: April 2021

Memory consolidation is thought to occur through protein synthesis-dependent synaptic plasticity mechanisms such as long-term potentiation (LTP). Dynamic changes in gene expression and epigenetic modifications underlie the maintenance of LTP. Similar mechanisms may mediate the storage of memory. Key plasticity genes, such as the immediate early geneArc, are induced by learning and by LTP induction. Mice that lack Arc have severe deficits in memory consolidation, and Arc has been implicated in numerous other forms of synaptic plasticity, including long-term depression and cell-to-cell signaling. Here, we take a comprehensive approach to determine if Arc is necessary for hippocampal LTP in male and female mice. Using a variety of Arc knock-out (KO) lines, we found that germline Arc KO mice show no deficits in CA1 LTP induced by high-frequency stimulation and enhanced LTP induced by theta-burst stimulation. Temporally restricting the removal of Arc to adult animals and spatially restricting it to the CA1 using Arc conditional KO mice did not have an effect on any form of LTP. Similarly, acute application of Arc antisense oligodeoxynucleotides had no effect on hippocampal CA1 LTP. Finally, the maintenance ofin vivoLTP in the dentate gyrus of Arc KO mice was normal. We conclude that Arc is not necessary for hippocampal LTP and may mediate memory consolidation through alternative mechanisms.SIGNIFICANCE STATEMENTThe immediate early gene Arc is critical for maintenance of long-term memory. How Arc mediates this process remains unclear, but it has been proposed to sustain Hebbian synaptic potentiation, which is a key component of memory encoding. This form of plasticity is modeled experimentally by induction of LTP, which increases Arc mRNA and protein expression. However, mechanistic data implicates Arc in the endocytosis of AMPA-type glutamate receptors and the weakening of synapses. Here, we took a comprehensive approach to determine if Arc is necessary for hippocampal LTP. We find that Arc is not required for LTP maintenance and may regulate memory storage through alternative mechanisms.
Cell-Type-Specific Dynamics of Calcium Activity in Cortical Circuits over the Course of Slow-Wave Sleep and Rapid Eye Movement Sleep
Authors: Niethard Niels , Brodt Svenja , Born Jan 
Published: April 2021

Sleep shapes cortical network activity, fostering global homeostatic downregulation of excitability while maintaining or even upregulating excitability in selected networks in a manner that supports memory consolidation. Here, we used two-photon calcium imaging of cortical layer 2/3 neurons in sleeping male mice to examine how these seemingly opposing dynamics are balanced in cortical networks. During slow-wave sleep (SWS) episodes, mean calcium activity of excitatory pyramidal (Pyr) cells decreased. Simultaneously, however, variance in Pyr population calcium activity increased, contradicting the notion of a homogenous downregulation of network activity. Indeed, we identified a subpopulation of Pyr cells distinctly upregulating calcium activity during SWS, which were highly active during sleep spindles known to support mnemonic processing. Rapid eye movement (REM) episodes following SWS were associated with a general downregulation of Pyr cells, including the subpopulation of Pyr cells active during spindles, which persisted into following stages of sleep and wakefulness. Parvalbumin-positive inhibitory interneurons (PV-In) showed an increase in calcium activity during SWS episodes, while activity remained unchanged during REM sleep episodes. This supports the view that downregulation of Pyr calcium activity during SWS results from increased somatic inhibition via PV-In, whereas downregulation during REM sleep is achieved independently of such inhibitory activity. Overall, our findings show that SWS enables upregulation of select cortical circuits (likely those which were involved in mnemonic processing) through a spindle-related process, whereas REM sleep mediates general downregulation, possibly through synaptic re-normalization.SIGNIFICANCE STATEMENTSleep is thought to globally downregulate cortical excitability and, concurrently, to upregulate synaptic connections in neuron ensembles with newly encoded memory, with upregulation representing a function of sleep spindles. Usingin vivotwo-photon calcium imaging in combination with surface EEG recordings, we classified cells based on their calcium activity during sleep spindles. Spindle-active pyramidal (Pyr) cells persistently increased calcium activity during slow-wave sleep (SWS) episodes while spindle-inactive cells decreased calcium activity. Subsequent rapid eye movement (REM) sleep episodes profoundly reduced calcium activity in both cell clusters. Results indicate that SWS allows for a spindle-related differential upregulation of ensembles whereas REM sleep functions to globally downregulate networks.
PENGEMBANGAN BAHAN AJAR KIMIA DASAR BERBASIS CONCEPTUAL CHANGE TEXT PADA MATERI REDOKS
Authors: Sukmawati Wati , Kadarohman Asep , Sumarna Omay , Sopandi Wahyu 
Published: April 2021

DEVELOPMENT OF TEACHING MATERIALS BASED ON CONCEPTUAL CHANGE TEXT ON REDOX MATERIALS FOR BASIC CHEMICALS ON REDOX CONCEPTAbstractThe problem in this study is that there are still many students who have difficulty learning basic chemical concepts and experience misconceptions. One way to overcome student difficulties in understanding the concept of chemistry is to provide quality learning media. This study aims to produce learning media in the form of quality teaching materials. The teaching materials developed are chemical teaching materials based on Conceptual Change Text (CCT). The research data were obtained from the results of validation of teaching materials from experts and the results of a questionnaire distributed to 30 students. This research was conducted using the R&D method with the research subjects being teaching materials and students. Based on the data generated in this study, it was found that the development of CCT-based teaching materials when viewed from the aspects of content feasibility, presentation feasibility, language assessment, multiple chemical representations assessed by some experts, it can be concluded that the teaching materials developed are good and suitable for use in the field with some improvements with an average validation value of 4. Besides, a limited test was also carried out on students of the teaching materials that were being developed and students responded well to the teaching materials because it could help them understand the average value of 85. AbstrakPermasalahan dalam penelitian ini adalah masih banyaknya mahasiswa yang mengalami kesulitan dalam belajar konsep kimia dasar dan mengalami miskonsepsi. Salah satu cara untuk mengatasi kesulitan mahasiswa dalam memahami konsep kimia adalah menyediakan media pembelajaran yang berkualitas. Penelitian ini bertujuan untuk menghasilkan media pembelajaran berupa bahan ajar yang berkualitas. Bahan ajar dikembangkan adalah bahan ajar kimia berbasis Conceptual Change Text (CCT). Data penelitian diperoleh dari hasil validasi bahan ajar dari para ahli dan hasil angket yang disebarkan kepada 30 orang mahasiswa. Penelitian ini dilakukan dengan metode R&D dengan subjek penelitian adalah bahan ajar dan mahasiswa. Berdasarkan data yang dihasilkan dalam penelitian ini diperoleh hasil bahwa pengembangan bahan ajar berbasis CCT jika dilihat dari aspek kelayakan isi, kelayakan penyajian, penilaian bahasa, penilaian multiple representasi kimia yang dinilai oleh beberapa ahli dapat disimpulkan bahwa bahan ajar yang dikembangkan sudah baik dan layak digunakan di lapangan dengan beberapa perbaikan dengan rata-rata nilai validasi 4. Selain itu juga dilakukan uji terbatas terhadap mahasiswa terhadap bahan ajar yang sedang dikembangkan dan mahasiswa merespon dengan baik bahan ajar tersebut karena bisa membantu mereka dalam memahami dengan rata-rata nilai 85. konsep.
Influence of polymer structure and amount on microstructure and properties of polyethylene-modified asphalt binders
Authors: Roja K. Lakshmi , Rehman Amara , Ouederni Mabrouk , Krishnamoorthy Senthil Kumar , Abdala Ahmed , Masad Eyad 
Published: April 2021

AbstractIn recent years, the use of polyethylene (PE) for asphalt modification has been gaining increased attention due to the environmental sustainability and cost-saving benefits. To optimize the performance of the PE-asphalt blends, it is necessary to understand the polymer-binder interactions and their impact on the properties of the modified asphalt binder. In this study, low-density polyethylene (LDPE) with low and high melt flow index (MFI), i.e., LDPE4 and LDPE70, were blended with Pen 60-70 asphalt binder in dosages ranging from 1 to 5 wt.%. PE Wax was also added to the binder or the PE-binder blend to enhance dispersion. The dispersion of PE in the binder and the phase stability of the modified binder were investigated by optical microscope. The equivalent diameter of PE domains increased with time and the polymer dosage level. The addition of PE wax improved the polymer dispersity in the LDPE4 blends. The polymer dispersity in LDPE70 blends was good without adding PE Wax, attributed to the higher MFI value (low molecular weight) of LDPE70. In addition, to understand the stability of polymer modified binder, the steady shear viscosity-temperature profile of these binders was studied using a rotational viscometer. The dynamic rheological properties and performance of the PE-binder blends were evaluated using the dynamic shear rheometer. Based on the microstructure, all other rheological and performance properties, it was concluded that the 3% LDPE70 binder has better polymer dispersity, better low and high temperature performance characteristics.
Barriers to the implementation of point-of-care ultrasonography by physiotherapists in haemophilia treatment centres in Canada: a modified Delphi approach
Authors: Strike Karen , Chan Anthony , Maly Monica R. , Solomon Patricia 
Published: April 2021

Abstract

Background
In patients with haemophilia, evidence suggests that the physical examination alone is not sensitive enough to detect small amounts of blood within a joint. Attention has shifted to methods of improving the sensitivity of the physical examination through adding diagnostic modalities such as point-of-care ultrasonography (POC-US). Proficiency with the physical examination and understanding of the role of POC-US are important competencies for physiotherapists. Despite training, implementation of POC-US by physiotherapists in haemophilia treatment centres in Canada has been mixed.

Aim
Using a theory-based approach, the aim of the current study is to achieve expert consensus regarding the barriers to physiotherapy performed POC-US in haemophilia treatment centres in Canada using a modified Delphi approach.

Materials and Methods
Using the Knowledge-to-Action Framework and the Consolidated Framework for Implementation Research (CFIR), a modified Delphi approach was completed using the Modified BARRIERS Scale (MBS). Participants were blinded and consensus was reached over three rounds at the Canadian Hemophilia Society’s annual three-day conference.

Results
Twenty-two physiotherapists participated; 20 participants completed Round 1, and 21 completed Rounds 2 and 3. Four items of the MBS reached consensus: 1) The physiotherapist does not have time to read research related to POC-US; 2) The physiotherapist is isolated from knowledgeable colleagues with whom to discuss POC-US; 3) Administration will not allow POC-US implementation; 4) There is insufficient time on the job to implement new ideas. All four consensus items can be mapped to one domain of the CFIR: the inner setting.

Conclusion
The haemophilia treatment centre within a healthcare organisation appears to be an important target for addressing barriers to the implementation of physiotherapy performed POC-US.
Blood pressure in haemophilia and its relation to clotting factor usage
Authors: Gopal Srila , Barnes Richard FW , Quon Doris V , Sun Hao Wei Linda , Jackson Shannon , von Drygalski Annette 
Published: April 2021

Abstract

Background
Patients with haemophilia have a higher prevalence of hypertension than the general population that cannot be explained by traditional cardiovascular risk factors such as age, race, diabetes or obesity. Patients with severe haemophilia, who are on clotting factor prophylaxis, have a higher prevalence of hypertension compared to patients with milder forms of haemophilia, who infuse clotting factor less frequently. This raises the question of whether there is a link between clotting factor usage and blood pressure in haemophilia patients.

Methods
Data was collected from 193 patients with severe haemophilia presenting to three haemophilia treatment centres in the United States and Canada, including age, body mass index (BMI), blood pressure (BP), Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) infection status, and clotting factor usage from pharmacy prescriptions (units/kg/year). The correlation between BP and factor usage was examined using quantile regression models.

Results
Systolic and diastolic BP plotted against factor use showed a cone-shaped scatter of points. There was no association between clotting factor usage and higher systolic or diastolic BP.

Conclusion
Our observations provide no evidence for an association between increased clotting factor usage and high BP.
An analysis of deviations from international standards of physique development in male youngsters from the former aral sea region
Authors: Yerkudov Valerii O. , Pugovkin Andrey P. , Matchanov Azat T. , Rozumbetov Kenzhabek U. , Dauletov Ruslan K. , Rogozin Sergej S. , Pakhomova Maria A. 
Published: April 2021

Introduction. According to the commonly accepted classification, geographical division of the Southern Near-Aral region (Karakalpakstan, Republic of Uzbekistan) is determined by the distance from the epicenter of the formal Aral Sea ecological disaster. The physique development was compared in male youngsters living in Zone No. 1 (critical), Zone No. 2 (stable) and Zone No. 3 (normal). The aim was a comparison of body length and mass in male youngsters up to 17 years old living in all three zones.
Material and methods. Total body length and mass were studied in 320 male volunteers, age 1719. Z-index of body length and body mass index (BMI) were estimated according to the standards of WHO Growth Reference, 2007. Batch-to-batch variations were studied with KruskalWallis test, and MannWhitney criterion including Bonferroni correction for multiple comparison. Categorical features were compared using Fishers exact test for 33 contingency tables with calculating the proportion of children with one or another deviation in body weight. The results were considered statistically significant at p 0.05.
Results. Subjects from Zone 1 possessed significantly lower valued of BMI and Z-index. The incidence of Z-index values lower than mean (less 1 SD) were significantly higher in Zone 1 (critical).
Conclusion. The results may be explained by via chemical pollution of the environment by the endocrine-disrupting chemicals in the critical zone of the Aral See region ecological disaster and can be implied for the health monitoring of the local population.
Features of sexual development, immune status and biochemical parameters in boys suffering from acne
Authors: Pilnik Elena N. , Zaslavsky Denis V. , Pyatibrat Alexander O. 
Published: April 2021

Among skin diseases in children and adolescents, the most common pathology is acne. The main pathogenetic link of acne in adolescents is hormonal imbalance. The effect on the sebaceous glands of high concentrations of dihydrotestosterone causes a change not only in the quantitative but also in the qualitative composition of the sebaceous secretion. The study is devoted to assessing the characteristics of sexual development, immune status and biochemical parameters in boys suffering from acne. Materials and methods.
Materials and methods. A comparative analysis of the state of immunity, sexual development, biochemical parameters of 147 boys suffering from acne, and 142 healthy boys who do not suffer from acne.
It was found that the immune status of boys suffering from acne was characterized by a decrease in cytotoxic lymphocytes. In the peripheral blood of these boys, serum interferon , tumor necrosis factor , interleukins 1, 2, 8 and 10, as well as small circulating immune complexes were significantly higher than in the boys of the control group. In boys suffering from acne, in the puberty period, the concentration of prolactin in 1314 years is significantly lower, and testosterone levels are significantly higher than in boys of the control group of the same age. At 1517 years of age, the concentration of luteinizing hormone in boys with acne is significantly lower, and testosterone is higher than in boys in the control group. Evaluation of the degree of formation of secondary sexual characteristics indicates that boys suffering from acne differed from their peers from the control group by a small advance in sexual development. Thus, boys suffering from acne, characterized by advanced and disharmonious puberty.
Early silvicultural performance of eucalypt species grown in environmental conditions of the tropical dry forest of Colombia
Authors: Báez-Aparicio Camila Andrea , López-Aguirre Ana Milena , Barrios-Trilleras Alonso 
Published: April 2021

The establishment of new forest plantations requires making important decisions starting with the selection of the species to be planted, as well as the choice of an adequate planting spacing to guarantee the maximization of wood production. The aim of this study was to evaluate the performance of nine eucalypt species planted with three different spacings under the environmental conditions of the tropical dry forest of the inter-Andean valleys of Colombia. A split-plot arrangement with two replicates was used as the experimental design. The planting spacing factor (three planting spacings) was assigned to the main plots and the species factor (nine eucalypt species) was assigned to the subplots. Survival and growth were evaluated at twenty-four months of age. The study identified the Brazilian provenances of Eucalyptus camaldulensis Dehnh, Eucalyptus urophylla S.T. Blake, Eucalyptus grandis W. Hill, and Eucalyptus pellita F. Muell. and the Colombian provenance of Eucalyptus pellita F. Muell. as promising for commercial reforestation programs in areas with a water deficit in the tropical dry forest. Planting spacings of 3×2 m (1666 stems·ha-1) and 3×2.5 m (1333 stems·ha-1) maximized the production of basal area and the volume for the species evaluated. Finally, no interaction was detected between species and planting spacing factors, therefore, the species identified had a better performance regardless of the planting spacing used.
CORRELATION OF PERSONAL AND INSTITUTIONAL FACTORS WITH RESEARCH PRODUCTIVITY AMONG UNIVERSITY TEACHERS
Authors: Batool Ayesha , Ahmad Saghir , Naz Sadaf 
Published: April 2021

Purpose of the study: The purpose of the research was to explore the association of teachers’ particular and university factors to enhance research production.
Methodology: The design of the research was correlational. It was descriptive and survey research. Teaching personnel of universities participated in this research. Teachers were selected from departments by stratified technique. The self-developed questionnaire related to variables was used for data collection. The relationship was explored by using Pearson r among variables of the study.
Main Findings: It was found that different components of institutional elements research procedure of departments, job and compensation, and assets and helping material have a poor, however positive correlation with research profitability of teaching personnel.
Applications of this study: The findings of the study are applicable in universities. The leadership may take steps for the improvement and promote research culture at a higher level.
Novelty/Originality of this study: Personal and institutional factors of research productivity were explored in this study. This study determines that how both types of elements are crucial and affect the research productivity of teachers.
Clinical and psychological aspects of insomnia associated with COVID-19 pandemic
Authors: Alekhin A. N. , Leonenko N. O. , Kemstach V. V. 
Published: April 2021

Background. In addition to clinical, epidemiological, and political aspects, the pandemic situation has a clinical and psychological aspect, as long as the measures taken to counteract infection inevitably cause unusual living conditions for a large number of people. Stress experience is accompanied by changes in autonomic regulation and, as a result, a number of somatic shifts. Stress markers include sleep disorders, changes in appetite, gastrointestinal disorders, headaches, chest pain, dyspnea, body pain, dizziness, numbness, fluctuations in blood pressure, sleep disorders, panic attacks, depressive and suicidal tendencies.Objective. We suggested that resilience is the predictor of successful resolution of existential crisis from the point of view of maintaining mental and somatic health, as well as gaining experience of deep self-improvement, strengthening of personality and potential for coping with life difficulties. Resilience includes coping at all levels of functioning — physical, psychological, social and existential. The latter defines the perception of reality itself as a challenge of complexity that requires coping, and regulates resilience at all other levels. The indicator of sleep quality was used as an empirical criterion to evaluate coping with stress. It is both an indicator and an antistress resource for physical functioning. The hypothesis of the study was the assumption that psychological content of resilience differs in subjects with moderate severity insomnia and with no sleep disturbances during pandemic period.Design and methods. To evaluate this hypothesis during the period of self-isolation in connection with the COVID-19 pandemic (April-May 2020), an empirical study was carried out on a randomized sample of 93 subjects using clinical and psychological scales.Results. This research resulted in the identification of differences in psychological content of resilience which reflect clinical and psychological characteristics in subjects with moderate severity insomnia and with normal sleep during the pandemic. The psychological content of resilience in respondents without sleep disturbances during the pandemic can be considered as complex and mature mechanisms of personality self regulation that allow of maintaining mental and somatic health, efficiency, ability to develop. Identified features can be used as psychotherapeutic targets in patients at different stages of exposure to stress factors.