Hasil untuk "Science (General)"

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S2 Open Access 2011
Validity and Reliability in Social Science Research

Ellen A. Drost

Concepts of reliability and validity in social science research are introduced and major methods to assess reliability and validity reviewed with examples from the literature. The thrust of the paper is to provide novice researchers with an understanding of the general problem of validity in social science research and to acquaint them with approaches to developing strong support for the validity of their research.

1108 sitasi en Computer Science
DOAJ Open Access 2026
Aplicação da análise da fiabilidade e do dimensionamento probabilístico ao reforço de taludes rochosos

Renato Pereira, José Muralha, Luís Lamas

Este artigo explora a aplicação de métodos probabilísticos na análise da fiabilidade e no dimensionamento do reforço de taludes rochosos sujeitos a mecanismos de rotura planar. O estudo incide no caso de um maciço rochoso intersetado por uma família de descontinuidades paralela à face do talude. O volume com potencial de instabilização é idealizado como um modelo de blocos, para o qual se desenvolve uma formulação em sistemas de componentes. Como termo de comparação, analisa-se igualmente um modelo simplificado que considera o mesmo volume como um bloco único. Os resultados evidenciam a influência da inclinação do plano de deslizamento. Verifica-se que o modelo constituído por múltiplos blocos conduz a índices de fiabilidade inferiores. Contudo, a sua utilização para o dimensionamento probabilístico do reforço tem vantagens apenas para inclinações baixas do plano de deslizamento. A análise sugere ainda que o modelo de blocos múltiplos pode ser adequadamente representado por um modelo simplificado de dois blocos.

Geology, Engineering geology. Rock mechanics. Soil mechanics. Underground construction
DOAJ Open Access 2026
Epistemic artifacts and changing patterns of observation

Heriberto Ramírez Luján

This paper explores how epistemic artifacts have transformed our understanding of scientific observation. It examines the historical evolution from basic instruments such as Mayan quadrants and Galileo’s telescope to today’s sophisticated electron microscopes. The study focuses on how these devices have reshaped the traditional concept of observation in the philosophy of science, particularly within the field of nanotechnology. Against the backdrop of historical figures such as Descartes, Hooke, Newton, and Leeuwenhoek, it highlights how each contributed to the development of the «microscopic artifactual tradition». The paper introduces the concept of nanoepistemology to describe how knowledge of the nano-world fundamentally depends on instrument-processed images rather than traditional direct observation. It concludes that these technological transformations have weakened the role of classical theories and have shifted the philosophy of science toward a philosophy of technology.

Philosophy (General)
DOAJ Open Access 2025
Evaluation of the Applications of using Global free Digital Elevation Models and GNSS-RTK data for Agricultural purposes in Egypt using Machine Learning

Ashraf abdallah, Bara' Al-MISTAREHI, Amir SHTAYAT

Agriculture is a vital component of Egypt's economy; therefore, using Digital Elevation Models (DEMs) in agricultural planning in Egypt has significant benefits regarding water management, site appropriateness assessment, flood risk mitigation, and infrastructure construction. It is also essential for planners to make more informed decisions, optimize resource allocation, and support sustainable farming practices. This research paper investigates the accuracy of obtaining DEM data from four free global models (STRM30, ALOS30, COP30, and TanDEM-X90). The global DEM data has been compared to an actual GNSS-RTK DEM data surveyed onsite for two agricultural block areas in Aswan, the southern Government of Egypt. The two blocks are a part of a national project. For Block I and II, the RMSE of the Model STRM30 was 2.92 m and 3.59 m, respectively, indicating a poorer solution. Regarding accuracy, the ALOS30 model ranks third, reporting an RMSE of 2.58 m for block II and 3.30 m for block I. COP30 has an RMSE value of 1.06 m for blocks I and II and.91 m overall. TanDEM-X90 is the most accurate model in this investigation; block I provided an RMSE of 0.90 m with an SD of 0.58 m (SD95% = 0.38 m). After removing the anomalies, the model's stated RMSE for block II was 0.34 m, with an SD value of 0.62 m and 1.03 m. According to the classification using machine learning algorithms, with an accuracy of 84.7% for block I and 85% for block II, TanDEM-X90 is the best solution.

Engineering (General). Civil engineering (General)
DOAJ Open Access 2025
Unveiling the immunomodulatory dance: endothelial cells’ function and their role in non-small cell lung cancer

Sophia Daum, Lilith Decristoforo, Mira Mousa et al.

Abstract The dynamic interactions between tumor endothelial cells (TECs) and the immune microenvironment play a critical role in the progression of non-small cell lung cancer (NSCLC). In general, endothelial cells exhibit diverse immunomodulatory properties, influencing immune cell recruitment, antigen presentation, and regulation of immune checkpoint expression. Understanding the multifaceted roles of TECs as well as assigning specific functional hallmarks to various TEC phenotypes offer new avenues for targeted development of therapeutic interventions, particularly in the context of advanced immunotherapy and anti-angiogenic treatments. This review provides insights into the complex interplay between TECs and the immune system in NSCLC including discussion of potential optimized therapeutic opportunities.

Neoplasms. Tumors. Oncology. Including cancer and carcinogens
DOAJ Open Access 2025
Temperature orchestrates phytoplankton community and environment in mountain stream for enhancing resource use efficiency

Li Ji, Huayong Zhang, Huayong Zhang et al.

Warming is a key factor influencing the function of the structure and function of phytoplankton communities. However, the impacts of temperature on phytoplankton resource use efficiency (RUE) in mountain rivers remain poorly understood. Here, the spatiotemporal patterns of phytoplankton community structure (biomass, community composition, and diversity), function (RUE), and the main environmental factors in a high-latitude mountainous stream were investigated to assess how temperature affects the phytoplankton RUE. The results showed that phytoplankton species richness, biomass, and RUE all increased with rising temperature, with species richness significantly higher. There was a shift in the phytoplankton community from dominated by Cyanophyta at lower temperatures to dominated by Cryptophyta at higher temperatures. Phytoplankton RUE was significantly positively correlated to species richness, but no significant relationship was observed between RUE and Pielou’s evenness. Furthermore, redundancy analysis and Mantel tests revealed that water temperature, nutrient (TP, and NH4+-N) and physicochemical variable (flow velocity, and dissolved oxygen) explained 40.40% of the overall variation in phytoplankton RUE. Phytoplankton RUE exhibited stronger responses to environmental variables than phytoplankton biomass or diversity. The results highlighted that temperature directly affected phytoplankton community composition and enhanced RUE by altering environmental conditions and biodiversity. Temperature plays a crucial role in shaping the structure and function of phytoplankton communities in rivers. Our results contribute to the deep understanding of the mechanisms by which temperature influences RUE providing a basis for the sustainable management and conservation of aquatic ecosystems and watersheds.

Science, General. Including nature conservation, geographical distribution
DOAJ Open Access 2024
The Interaction between Adding Soybean Residue and Hydrogel to the Soil on the Mineral Content of Yellow Corn (Zea mays L.) Plants whose Seeds are Treated with Ascorbic Acid

Yasir Mahmood, Mohammad Faysail

This study was conducted in the warehouse of the Department of Biology / College of Education for Pure Sciences for the 2023-2024 season to study the effect of adding levels of hydrogel (0, 2, 4) gm/kg of soil and residues of the vegetative part of soybeans at levels (0, 4, 8) gm/kg soil in the mineral content of yellow corn plants soaked with concentrations of (0,100, 200 ppm) of ascorbic acid. The results were analyzed using a completely randomized design and a factorial experiment with three replications. The results confirmed the existence of a discrepancy in the effect of soybean residues on mineral elements, as they ranged between inhibition and stimulation, as the residues had a stimulating effect on the calcium and nitrogen elements, While its effect was inhibitory to the element sodium and magnesium, and the addition of hydrogel showed a stimulating effect in all the nutritional elements mentioned above. On the other hand, there was a significant superiority in the content of the elements with an increase in the concentration of ascorbic acid compared to the control treatment without addition. The interactions showed a stimulating effect, especially the interaction of hydrogel levels with ascorbic acid concentrations in the studied characteristics

Education, Science (General)
DOAJ Open Access 2024
Le recyclage des coquillages fossiles dans l’espace sénégambien : histoire et archéologie

Michel Waly DIOUF

Cet article examine la réutilisation des coquillages fossiles et décrit en même temps les anomalies ou les déformations observées sur les individus. La démarche adoptée repose en effet sur une combinaison de plusieurs activités allant de la recherche documentaire à l’examen du mobilier coquillier, en passant par les enquêtes ethnographiques, la prospection et les fouilles archéologiques. Nos fouilles effectuées sur le site de Balloum, près du village de Moundé (basSaloum) ont mis au jour des spécimens coquilliers déformés ou réutilisés le plus souvent en des objets de parures ou d’ustensiles. Mots-clés : ,

Anthropology, Sociology (General)
S2 Open Access 2020
NEW PLAYMAKER IN SCIENCE EDUCATION: COVID-19

M. Uşak, A. Masalimova, E. I. Cherdymova et al.

Nowadays, we all are sitting in our homes and watching what is going on in the world, as if we are watching a science fiction movie, in which we have the leading role. Novel Coronavirus (COVID-19), which first appeared in Wuhan (Abdulamir, & Hafidh, 2020; Ait Addi et al., 2020 Aljofan, & Gaipov, 2020; Sorooshian, 2020) and later turned into a pandemic affecting the entire world, does not discriminate between the degree of democracy, finances, religion, gender, ethnicity and region. World is a fireplace and we all are “burning”. In the countries where the pandemic is progressing rapidly, all health professionals, regardless of their area of expertise, have been called to the field. This reminds us of the need to revive the general perspective that we have begun to forget. That is to say, no matter how specific our area of expertise is, we are obliged to keep the general perspective of our field and basic doctrines constantly fresh.

102 sitasi en Political Science

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