Improved Methods for Fluorescence Microscopy Detection of Macromolecules at the Axon Initial Segment

The axonal initial segment (AIS) is the subcellular compartment required for initiation of the action potential in neurons. Scaffolding and regulatory proteins at the AIS cluster with ion channels ensuring the integrity of electrical signaling. Interference with the configuration of this protein network can lead to profound effects on neuronal polarity, excitability, cell-to-cell connectivity and brain circuit plasticity. As such, the ability to visualize AIS components with precision provides an invaluable opportunity for parsing out key molecular determinants of neuronal function. Fluorescence-based immunolabeling is a sensitive method for morphological and molecular characterization of fine structures in neurons. Yet, even when combined with confocal microscopy, detection of AIS elements with immunofluorescence has been limited by the loss of antigenicity caused by fixative materials. This technical barrier has posed significant limitations in detecting AIS components alone or in combination with other markers. Here, we designed improved protocols targeted to confocal immunofluorescence detection of the AIS marker fibroblast growth factor 14 (FGF14) in combination with the cytoskeletal-associated protein Ankyrin-G, the scaffolding protein βIV-spectrin, voltage-gated Na+ (Nav) channels (especially the Nav1.6 isoform) and critical cell type-specific neuronal markers such as parvalbumin, calbindin, and NeuN in the mouse brain. Notably, we demonstrate that intracardiac perfusion of animals with a commercially available solution containing 1% formaldehyde and 0.5% methanol, followed by brief fixation with cold acetone is an optimal and sensitive protocol for FGF14 and other AIS marker detection that guarantees excellent tissue integrity. With variations in the procedure, we also significantly improved the detection of Nav1.6, a Nav isoform known for its fixative-sensitivity. Overall, this study provides an ensemble of immunohistochemical recipes that permit excellent staining of otherwise invisible molecules within well-preserved tissue architecture. While improving the specific investigation of AIS physiology and cell biology, our thorough study can also serve as a roadmap for optimizing immunodetection of other fixative-sensitive proteins expanding the repertoire of enabling methods for brain studies

The Impact of the Teacher’s Personality on the Motivation of Learning the English Language Among Governmental School Students in Saudi Arabia

The current study aimed to identify the impact of the teachers personality on the motivation of learning English among government school students in the city of Abha, Saudi Arabia. The descriptive correlative method was used, and two questionnaires were designed to collect the data. They were distributed electronically, and the study targeted a sample of English language teachers in public secondary schools in Abha, and a sample of high school students in Abha, who were chosen randomly in a simple way. The results of the study showed that English language teachers have personal characteristics that qualify them to teach in high government schools, with an average of (3.6918), which is considered as a highly - approved degree, and that students have a motivation to learn English with an average of (3.7828), which means they scored a high degree of approval. The results also showed the effect of the teachers personality on the motivation of students towards learning English. The results also showed that it is possible to predict the motivation of learning English through the teachers personality

Challenges Hindering a Supportive Culture of Dialogue in Saudi Arabia

This study identified challenges hindering high school administration to establish a supportive culture of dialogue within the school. A questionnaire was subsequently designed, and its validity and reliability were verified. The questionnaire was then applied to a randomly selected sample of high school principals (N=39) and teachers (N=115) in Riyadh, Saudi Arabia. The researchers used various statistical methods appropriate for analyzing the collected data. Among the key findings of the study include: (1) administration of Riyadh high schools support building a supportive organizational culture of dialogue; and (2) the main challenges for them in establishing a supportive culture of dialogue were related to Organizational, Physical and Human difficulties. The study, therefore, recommended providing guidelines and assistance for creating a supportive culture of dialogue, including the provision of necessary training for the administration and teachers to enhance their abilities to build an appropriate culture of dialogue. Keywords: Culture of dialogue, dialogic pedagogy, high schools, organizational culture, Saudi Arabia

Optimization of sol-immobilized bimetallic Au–Pd/TiO2 catalysts: reduction of 4-nitrophenol to 4-aminophenol for wastewater remediation

A sol-immobilization method is used to synthesize a series of highly active and stable AuxPd1−x/TiO2 catalysts (where x = 0, 0.13, 0.25, 0.5, 0.75, 0.87 and 1) for wastewater remediation. The catalytic performance of the materials was evaluated for the catalytic reduction of 4-nitrophenol, a model wastewater contaminant, using NaBH4 as the reducing agent under mild reaction conditions. Reaction parameters such as substrate/metal and substrate/reducing agent molar ratios, reaction temperature and stirring rate were investigated. Structure-activity correlations were studied using a number of complementary techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The sol-immobilization route provides very small Au–Pd alloyed nanoparticles, with the highest catalytic performance shown by the Au0.5Pd0.5/TiO2 catalyst.This article is part of a discussion meeting issue ‘Science to enable the circular economy’

ROLE OF THE PHYSICAL ACTIVITY IN THE IMPROVEMENT OF CARDIAC MEASURES AND DECLINING OF COMORBIDITIES.

Background: Regular physical activity (PA) can prevent many non-communicable diseases, such as cardiovascular disease (CVD) and diabetes mellitus (DM). The present study aimed to assess the health benefits of physical activities including blood pressure and comorbid conditions. Methodology: This is a prospective cohort case-control study that recruited 300 Saudi volunteers living in the city ofHail, Northern Saudi Arabia. Results: Out of 300 participants 155(51.7%) were males and 145 (48.3%) were females. There were 111(37%) participants committed to regular physical activity and the remaining 189(63%) without a defined commitment to physical activity (Uncommitted). Among 111 persons who claimed a commitment to regular physical activity (committed), 61(55%) were males and 50(45%) were females. The majority of committed individuals were at the age group 21-25 years followed by age group 26-30 and 31-35 years representing 32, 30, and 20 persons, respectively. The physical activity was highly practiced at the age range 21-30 years and this was found to be statistically significant P < 0.001. Conclusion: There is a low prevalence of physical activity in Hail region, particularly among females, which necessitates the suggestion of appropriate awareness programs. Younger and elder populations are in much need to be targeted with PA awareness programs

Study on a thermally driven refrigerator based on an organic Rankine cycle and vapor compression refrigeration combined by single rotor expander-compressor

Environmental degradation is still a major global concern as a result of the widespread usage of high-grade energy derived from fossil fuels, which emit greenhouse gases in abundant. Countries and companies all over the world are dealing with these issues, looking for sustainable and environmentally beneficial solutions. One such promising path is using the organic Rankine cycle (ORC) to capture heat, particularly from low temperature sources. The ORC's ability to convert otherwise wasted energy into useable power places it at the forefront of strategies aimed at reducing emissions and combating environmental impact. Given this context, this study goes thoroughly into the novel single rotor expander-compressor device's innovative potential. This device, which is intended for use in both a VCR cycle and an ORC, is positioned as a transformative tool in energy optimization and sustainable refrigeration. A detailed and comprehensive numerical model of the ORC-VCR was constructed to accurately describe and assess the performance of this integrated system. This model serves as a predictive tool for practical use cases to ensure its accuracy and reliability. The study rigorously evaluated the thermal efficiency of this integrated cycle. Thorough evaluations were conducted, taking into account the varying temperatures at which evaporation occurs in both the ORC (62.75 °C – 89.7 °C) and VCR (-20 °C – 5 °C) systems, the range of temperatures at which condensation occurs in the ORC system (20 °C – 45 °C), and the rotor speed (500 – 3000 rpm), all while keeping the heat source temperature constant (95 °C). These characteristics played a crucial role in understanding the operating limits and effectiveness of the combined system. The maximum cooling performance achieved was 5.38 kW, with a heat to cooling efficiency of 56%, attained at an ORC evaporation temperature of 62.75°C and a VCR temperature of -5°C, alongside an ORC condensation temperature of 20.5°C. it was observed that cooling performance consistently improved with increasing rotor speeds, whereas rotor speed changes did not affect the heat-to-cooling efficiency. Other than energy analysis of the system, exergy analysis was conducted for the same system. By analyzing the exergy destruction contributions of each component within the ORC-VCR system, it was found that the ORC evaporator had the most substantial impact on total exergy destruction. However, the VCR evaporator's contribution could significantly increase if the evaporation temperature in the VCR were further reduced. The highest overall exergy efficiency recorded was 63%, with ORC and VCR evaporation temperatures set at 62.75 °C and -5 °C, respectively, and an ORC condensation temperature of 20.5 °C. Notably, overall exergy efficiency remained unaffected by variations in rotor speed. In addition, this study explores the field of refrigerants, assessing other prospective refrigerants such as R245fa, R123, R134a, R1234ze(E), R1234yf, and Butane. Their performance is evaluated based on important indications, namely the heat-to-cool ratio efficiency, exergy efficiency, and the overall system efficiency. After this in-depth investigation, an examination of the VCR-ORC integration's potential influence on the environment was carried out, with a particular focus on aspects including consumption of fuel and CO2 emissions. In its essence, this research offers a perspective on the environmentally responsible integration of VCR and ORC systems. By combining these cycles, not only demonstrating the potential for improving energy efficiency, but also propose ways to address the urgent problem of emissions of greenhouse gases

The Use of Advanced Spectral Imaging to Reveal Nanoparticle Identity in Biological Samples

Nanoparticles (NPs) have been used in drug delivery therapies, medical diagnostic strategies, and as current Covid-19 vaccine carriers. Many microscope-based imaging systems have been introduced to facilitate detection and visualization of NPs. Unfortunately, none can differentiate the core and the shell of NPs. Spectral imaging has been used to distinguish a drug molecule and its metabolite. We have recently integrated this technology to a resolution of 9 nm by using artificial intelligence-driven analyses. Such a resolution allowed us to collect many robust datapoints for each pixel of an image. Our analyses could recognize 45 spectral points within a pixel to detect unlabeled Ag-NPs and Au-NPs in single live cells and tissues (liver, heart, spleen and kidneys). The improved resolution and software provided a more specific fingerprinting for each single molecule, allowing simultaneous analyses of 990 complex interactions from the 45 points for each molecule within a pixel of an image. This in turn allowed us to detect surface-functionalization of Ag-NPs to distinguish the core from the shell of Ag-NPs for the first time. Our studies were validated using various laborious and time-consuming conventional techniques. We propose that spectral imaging has tremendous potential to study NP localization and identification in biological samples at a high temporal and spatial resolution, based primarily on spectral identity information

The Challenges of Psychological Adjustment for International Students: A Critical Analysis of Coping Mechanisms and Support Services

This paper critically analyzes the challenges of psychological adjustment faced by international students and explores coping mechanisms and support services that can help them overcome these challenges. The essay first introduces the background information on international students and highlights the importance of psychological adjustment for their well-being and academic success. The challenges of psychological adjustment, including cultural, academic, social adjustment, and language barrier, are discussed in detail. The essay then explores coping mechanisms, including problem-focused coping, emotion-focused coping, seeking social support, and cultural adjustment programs, and the support services, including counseling services and international student services, that can help international students adjust to their new environment. Finally, the essay evaluates the effectiveness of these coping mechanisms and support services, emphasizing the importance of cultural competence in providing effective support services. This essay has practical implications for higher education institutions in providing tailored support to international students and highlights the need for future research to explore the effectiveness of coping mechanisms and support services for different groups of international students and the impact of the COVID-19 pandemic on their psychological adjustment