Ho Chi Minh City Open University Journal of Science
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Gülnar ve Silifke (Mersin-Türkiye) ilçelerindeki bazı doğal sit alanlarının flora, genel vejetasyon yapısı ve EUNIS habitat tiplerinin incelenmesi
No full textGülnar ve Silifke (Mersin-Türkiye) ilçelerindeki bazı doğal sit alanlarının flora, genel vejetasyon yapısı ve EUNIS habitat tiplerinin incelenmesi Bu araştırma Mersin (Türkiye) ili Gülnar, Mut ve Silifke ilçelerinde bulunan Çağlayan, Ilısu ve Yerköprü Şelalesi, Göksu Deltası, Narlıkuyu, Roma Kalıntıları, Şeytanderesi ve Cambazlı Sarnıcı ile Akdere Tahta Limanı doğal sit alanlarının floristik özelliklerini, EUNIS habitat tiplerini ve genel vejetasyon yapısını belirlemek amacıyla gerçekleştirilmiştir. Araştırmada toplam 65 familya ve 174 cinse ait 218 farklı takson tespit edilmiştir. Çağlayan Şelalesi’nde 31, Ilısu Şelalesi’nde 32, Yerköprü Şelalesi’nde 55, Göksu Deltasında 62, Narlıkuyuda 47, Roma Kalıntılarında 26, Akdere Tahta Limanında 63, Şeytanderesi ve Cambazlı Sarnıcında 85 takson belirlenmiştir. Bu araştırmada toplam 8 adet (%3.66) endemik bitki taksonu tespit edilmiştir. Fitocoğrafik bölgelere göre taksonların 77 taksonun Akdeniz (%35.32), 11 taksonun Avrupa-Sibirya (%5.04), 7 taksonun İran-Turan (%3.21) elementi, 45 taksonun Geniş yayılışlı (%20.64) ve 78 taksonun fitocoğrafik bölgesi belli olmayan (%35.77) şeklinde dağılım gösterdiği belirlenmiştir. Bu çalışmada 9 ana habitat, 22 alt habitat tipi tanımlanmıştır. Genel vejetasyon yapısı itibariyle çalışma alanlarının tamamında Quercetea İlicis ve Cisto-Micromerietea sintaksonomik sınıflarının karakter türlerine rastlanılmıştır. Göksu Deltası ile Şeytan Deresi ve Cambazlı Sarnıcı hariç diğer tüm alanlarda Quercetea Pubescentis sınıfının karakter türleri gözlemlenmiştir. Şeytan Deresi ve Cambazlı Sarnıcı ile Akdere Tahta Limanında diğerlerinden farklı olarak Querco-Fagetea sintaksonomi sınıfına ait karakter türler bulunduğu belirlenmiştir. Anahtar kelimeler: Doğal sit, flora, eunis habitat tipleri, vejetasyon, mersin.The aim of this study was to determine the floristic characteristics, EUNIS habitat types, and general vegetation structure of Çağlayan, Ilısu, and Yerköprü Waterfalls, Göksu Delta, Narlıkuyu, Roman Ruins, Şeytanderesi, and Cambazlı Cistern and Akdere Tahta Port natural site areas in Gülnar and Silifke districts of Mersin (Türkiye). According to the findings, 214 different taxa belonging to 65 families and 173 genera were identified. A total of 31 taxa were identified in Çağlayan Waterfall, 32 in Ilısu Waterfall, 54 in Yerköprü Waterfall, 62 in Göksu Delta, 47 in Narlıkuyu, 26 in Roman Ruins, 63 in Akdere Tahta Port, 84 in Şeytanderesi, and Cambazlı Cistern. A total of 8 (3.66%) endemic plant taxa were identified in the research areas. According to the phytogeographic regions, 77 taxa are Mediterranean (35.32%), 11 taxa are Euro-Siberian (5.04%), 7 taxa are Irano-Turanian (3.21%), 45 taxa are widely distributed (20.64%), and 76 taxa are of unknown phytogeographic region (35.77%). In this study, 9 main habitats and 22 sub-habitat types were identified. In terms of general vegetation structure, characteristic species of Quercetea ilicis and Cisto- Micromerietea syntaxonomic classes were found in all study areas. Character species of Quercetea pubescentis class were observed in all areas except Göksu Delta, Şeytan Creek, and Cambazlı Cistern. In Şeytanderesi and Cambazlı Cistern, and Akdere Tahta Port, character species belonging to the Querco-Fagetea syntaxonomy class were found differently from the others. These results contribute to the flora and vegetation literature by determining the flora of Mersin province, determining the EUNIS habitat types of natural sites in this country, and determining the general vegetation structure of the research area
Định tính vi khuẩn Yersinia enterocolitica gây viêm ruột trên heo nhà (Sus scrofa domesticus) bằng Nested PCR
Full text linkFood safety is an urgent issue as Yersinia enterocolitica, the major cause of Yersiniosis, is transmitted from domestic pigs (Sus scrofa domesticus). In Hanoi, the prevalence of contamination in pork samples has reached 16.67%. Since traditional detection methods are often time-consuming and ineffective, this study employed the Nested PCR method to enable early and accurate identification of Y. enterocolitica in pigs. Two specific genes were identified via bioinformatics analysis: the EX-sxy gene as an external primer for the genus Yersinia and the sxy gene as an internal primer for the species Y. enterocolitica. The primer sets were evaluated for specificity and amplification capabilities under in vitro and ex vivo conditions, and tested with control bacteria such as Salmonella enterica, Listeria monocytogenes, and Bacillus cereus. The Nested PCR successfully amplified the target gene fragments. The electrophoresis results showed bands of the expected sizes, 1,319bp for the EX-sxy gene and 564bp for the sxy gene. The study developed an efficient Nested PCR method, providing a vital tool for early and accurate diagnosis, contributing to enhancing food safety measures and protecting public health.An toàn thực phẩm là một vấn đề cấp thiết khi Yersinia enterocolitica, tác nhân chính gây bệnh Yersiniosis, lây nhiễm từ heo nhà (Sus scrofa domesticus). Tại Hà Nội, tỷ lệ nhiễm khuẩn trong thịt heo lên tới 16.67%. Do các phương pháp phát hiện truyền thống thường tốn thời gian và kém hiệu quả, nghiên cứu đã áp dụng phương pháp Nested PCR để phát hiện Y. enterocolitica nhanh chóng và chính xác trên heo. Hai gen đặc hiệu được xác định qua phân tích tin sinh học là gen EX-sxy làm mồi ngoài cho chi Yersinia và gen sxy làm mồi trong cho loài Y. enterocolitica. Các bộ mồi được đánh giá tính đặc hiệu và khả năng khuếch đại trong điều kiện in vitro và ex vivo, đồng thời kiểm tra với các vi khuẩn đối chứng như Salmonella enterica, Listeria monocytogenes và Bacillus cereus. Phản ứng Nested PCR đã khuếch đại thành công các đoạn gen mục tiêu. Kết quả điện di cho thấy các vạch sản phẩm có kích thước như mong đợi, 1,319bp cho gen EX-sxy và 564bp cho gen sxy. Các cặp mồi được chứng minh độ đặc hiệu cao trong cả hai điều kiện, không xảy ra khuếch đại chéo với DNA đối chứng. Nghiên cứu đã phát triển một phương pháp Nested PCR hiệu quả, cung cấp công cụ chẩn đoán sớm và chính xác, góp phần cải thiện an toàn thực phẩm và bảo vệ sức khỏe cộng đồng.
Investigation of the Properties of Ni-B Alloy Nanocomposite Coatings Reinforced with TiC Particles Electrodeposited at Different Current Densities
No full textIn this study, stainless steel substrate was electrochemically coated with Ni-B/TiC nanocomposite material to improve its properties. A conventional Watts-type nickel bath containing suspended TiC nanoparticles was used as the electrolyte. The effect of current density on the properties of the obtained coatings was investigated at different TiC bath concentrations. The crystal structure, surface and cross-sectional morphology, elemental content of the coatings were evaluated by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS). In addition, corrosion resistance of the coatings was determined by Tafel and electrochemical impedance spectroscopy (EIS) techniques. The increase in current density caused an increase in crystal grain size at low TiC bath content (from 9.3 to 14.4 nm for 5 g/L TiC), while it caused a decrease at high TiC bath content (from 16.5 to 14.5 nm for 9 g/L TiC). Moreover, the increase in current density has a decreasing effect on the microhardness values of nanocomposite coatings (from 750 to 568 HV for 5 g/L TiC). The current density increase changed the coating surface structure from a cauliflower-like appearance to a flatter appearance with circular mounds. From the EDS results, it was found that the TiC content in the nanocomposite coatings decreased with increasing current density. According to the Tafel and EIS data, the corrosion resistance increases with increasing current density in nanocomposite coatings (corrosion current decreased from 2.83 × 10−5 to 1.91 × 10−5 A)
Evaluation of the Effect of Carving Materials Used in Dental Anatomy Courses on Students' Preferences and Performance
No full textUrban mobility analysis of megacity New York using density-based clustering techniques
No full textThis study presents a comparative analysis of two density-based clustering algorithms, such as DBSCAN (Density-Based Spatial Clustering of Applications with Noise) and HDBSCAN (Hierarchical DBSCAN), to evaluate their performance in identifying taxi demand patterns. Using the New York City Taxi and Limousine Commission’s (TLC) September 2015 yellow taxi dataset, which includes variables such as trip distance, duration, fare amount, passenger count, and geographic coordinates, the research applies clustering and correlation analyses to uncover spatial and behavioral mobility insights. The dataset was preprocessed to remove noise and inconsistencies before implementing both algorithms. Results show that HDBSCAN outperforms DBSCAN by effectively detecting clusters with varying densities, particularly in central Manhattan, and providing clearer, more accurate representations of taxi demand. In contrast, DBSCAN classified a larger proportion of the data as noise, revealing its limitations when the data are heterogeneous and highlighting its limitations in handling heterogeneous spatial distributions. Complementary analysis using Pearson’s Product-Moment Correlation Coefficient revealed a weak positive relationship (r = 0.21) between trip distance and duration, indicating the influence of traffic and route variability, and a strong correlation (r = 0.92) between trip distance and fare, reflecting the city’s distance-based pricing structure. The findings demonstrate that HDBSCAN offers superior performance for analyzing large-scale transportation datasets. The study provides empirical evidence supporting its use in urban mobility research and practical insights for transportation planners and policymakers to maximize fleet distribution, manage demand, and improve service delivery. Future work should integrate contextual variables such as time of day, payment methods, and tipping behavior to achieve a more comprehensive understanding of urban transportation dynamics
Wound healing activities of eucalyptol on full thickness excisional skin wound model in rats
No full textA plant-derived monoterpene, eucalyptol (1,8-cineole), has been suggested to have antioxidant, anti-inflammatory, and antimicrobial properties. The wound-healing effects of eucalyptol remain unknown. This study aimed to evaluate the topical use of eucalyptol at two concentrations on a full-thickness excisional skin wound model in terms of wound healing, gene expression, biochemical changes, and histopathological changes. Sixty Wistar rats were randomly divided into 5 groups (n = 12 per group). The control group (C) was untreated. Full-thickness excisional skin wounds were created in the following groups: the vehicle group (V), which was treated with polysorbate 80 solution (negative control). The Dexpanthenol group (D) was treated with dexpanthenol ointment (positive control). Eucalyptol 5% (E5) and Eucalyptol 10% (E10) groups were treated with 5% and 10% eucalyptol, respectively. Wound areas were measured on days 1, 4, 7, 11, 14, 18, and 21 days after wound creation. Wound tissues were collected on days 7 and 21. Histopathological, gene expression (TNFα, IL10, TGFβ1, VEGF), and biochemical (MDA, rGSH, GPx, CAT) analyses were performed on the wound tissues. TNFα gene expression levels were upregulated in Groups V and E5 (P<0.05). IL10 levels were upregulated in the V, E5, and E10 groups (P<0.05). TGFβ1 was upregulated in all groups compared with the control. Significant differences in rGSH, GPx, CAT, and MDA levels were found among all groups (P<0.05). Topical administration of 10% eucalyptol accelerates wound healing. With respect to epidermal thickness, 5% eucalyptol resulted in superior wound healing. Further studies should include different wound models, tissue analyses, and combinations of eucalyptol with other agents
A multiple case study of Vietnamese university students’ perceptions of Quizlet in IELTS vocabulary learning
No full textOver the past decade, vocabulary learning has shifted from traditional paper-based methods to digital flashcards with gamification features to enhance engagement. While many studies have investigated the general benefits of digital tools such as Quizlet and Kahoot, few studies have explored students’ perceptions of these tools in Vietnam, especially in IELTS preparation classes. Thus, this study examines the perspectives of three Vietnamese university students from different majors who attended an IELTS class incorporating Quizlet. Findings revealed that Quizlet enhanced learners’ English vocabulary acquisition by promoting autonomy, competence, and relatedness. To effectively integrate Quizlet into Vietnamese universities, participants recommended early exposure, structured digital storage, and assessment via automated feedback to optimize learning outcomes. This study provides insights into the role of technology in vocabulary acquisition and offers practical recommendations for incorporating digital tools into English education in Vietnam