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Enhancing Substrate Selectivity and Activity of G. kaustophilus Lipase Using Mutation Studies
No full textLipazlar, yağların hidrolizini katalize eden hidrolaz sınıfı enzimlerdir. Biyoteknolojide özellikle biyodizel üretimi alanında önemli bir yeri bulunmaktadır. Bu enzimler, yağların transesterifikasyon reaksiyonunu katalize ederek bitkisel veya hayvansal yağlardan biyodizel elde etmeye yardımcı olmaktadır. Fakat, biyodizel üretiminde lipaz kullanımının bir takım sorunları bulunmaktadır. Reaksiyon verimliliğinin yetersizliği, özellikle yüksek serbest yağ asidi içeriğine sahip ham yağların transesterifikasyonunda önemli bir sorundur. Ayrıca, lipazların reaksiyon hızı açısından yeterince hızlı olmama duumu söz konusudur. Bunlara ek olarak, bu enzimler çevre koşullarına duyarlıdır; uygun sıcaklık veya pH koşulları olmaması durumu enzim aktivitesini olumsuz etkileyebilirken, kararlılık sorunlarını da beraberinde getirebilmektedir. Araştırmacılar, lipazların performansını artırmak ve süreç verimliliğini iyileştirmek için sürekli olarak yenilikçi yöntemler ve teknolojiler araştırmaktadır. Enzim mutasyonu ve lipaz immobilizasyonu, bu çabada odaklanılan önemli alanlardır. Bu çalışma, Geobacillus kaustophilus termofilik lipazının yapısal ve dinamik özellikleri hakkındaki anlayışımızı geliştirmeyi ve aktivitesini, substrat seçiciliğini ve termal kararlılığını iyileştirmek için mutasyonları kullanmayı amaçlamaktadır. İdeal mutasyonları bulmak için Gklip lipazı modellenmiş ve hem yabani tip hem de mutasyonlu yapıların ligand seçiciliğini değerlendirmek için farklı uzunlukta karbon zincirli yağ asitleri ile dok çalışmaları yürütülmüştür. Daha sonra, tüm protein-ligand kompleksleri için 50 ns moleküler dinamik simülasyonları gerçekleştirilmiştir. Simülasyonların son 30 ns'si MM/GBS analizi için kullanılmıştır. 36 mutasyondan, en iyi 5 tanesi daha ileri deneysel çalışmalar için seçilmiştir.Lipases are hydrolase class enzymes that catalyze the hydrolysis of fats. Their applications in biotechnology are particularly noteworthy in the field of biodiesel production. These enzymes help to obtain biodiesel from vegetable oils or animal fats by catalyzing the transesterification reaction of fats. However, there are some problems with the use of lipase in biodiesel production. Firstly, reaction efficiency is a significant problem, especially in trans-esterifying crude oils with high free fatty acid content. Also, lipases may not be fast enough in terms of reaction speed. Additionally, these enzymes are sensitive to environmental conditions; inappropriate temperature or pH conditions can negatively affect enzyme activity, while stability issues also exist. Researchers are continuously exploring innovative methods and technologies to enhance the performance of lipases and improve process efficiency. Enzyme mutation and lipase immobilization are vital areas of focus in this endeavor. This study aims to improve our understanding of the structural and dynamic properties of Geobacillus kaustophilus thermophilic lipase and use mutations to improve its activity, substrate selectivity, and thermal stability. The Gklip lipase was modeled to find the ideal mutations and docking studies were conducted to assess ligand selectivity of both wild-type and mutated structures with different-length carbon chain fatty acids. Then, 50 ns of molecular dynamic simulations were performed for all protein-ligand complexes. The last 30 ns of the simulations were used for MM/GBS analysis. Out of the 36 mutations, the top 5 were taken for further experimental studies
Scalable and Low-Power Reversible Logic for Future Devices: QCA and IBM-Based Gate Realization
No full textOne such revolutionary approach to changing the nano-electronic landscape is integrating reversible logic with quantum dot technology that will replace the conventional complementary metal-oxide semiconductors (CMOS) circuits for ultra-high speed, low density, and energy-efficient digital designs. The implementation of the reversible structure under the most inflexible conditions, as executed by quantum laws, is a highly challenging task. Furthermore, the enormous occupying areas seriously compromise the accuracy of the output in quantum dot circuits. Because of this challenge, quantum circuits can be employed as fundamental building blocks in highperformance digital systems since their implementation has a key impact on overall system performance. This study discusses a paradigm shift in nanoscale digital design by using a 4 x 4 reversible gate that redefines the basis of efficiency and precision. This reversible gate is elaborately used in a reversible full-adder circuit, fully symbolizing the core of minimum area, ultra-low energy consumption, and perfect output accuracy. The proposed reversible circuits have been fully realized using quantum-dot cellular automata technology (QCA), simulated, and verified by the highly reliable tool such as Qiskit IBM and QCADesigner 2.0.3. Furthermore, simulations results demonstrated the superiority of the QCA-based proposed adder, which reduced occupied area by 7.14 %, and cell count by 11.57 %, respectively. This work resolves some problems and opens new boundaries toward the future of digital circuits by addressing the main challenges of stability and pushing the boundaries of reversible logic design
Progress in Tourism Literature in Terms of Academic Outputs and Collaboration: A Comparison Between Türkiye and the World
No full textTurizm endüstrisinde yaşanan dönüşümlerin şüphesiz ulusal ve uluslararası turizm alanyazınının gelişimine ve farklı araştırma temalarında değişime yol açtığı bilinmektedir. Bu doğrultuda alanyazındaki akademik ve entelektüel gelişimi ortaya koymak amacıyla yürütülen çalışmalar giderek önemini korumaktadır. Bu çalışmanın amacı, farklı dönemler bazında Türkiye’deki turizm ile ilgili makale sayısı ve içeriğinde meydana gelen değişimin belirlenerek dünya ile kıyaslanması ve yürütülen ortak çalışmaların içeriği ve türü konusunda da kapsamlı bir analiz yapılmasıdır. Bu amaçla mevcut çalışma WOS ve SCOPUS veri tabanlarında taranan 126 farklı dergide yayımlanmış 2.163 Türkiye ve 73.779 uluslararası adresli makaleyi bibliyometrik yaklaşımla Bibliometrix kütüphanesi kullanılarak incelemiştir. Bulgular Türkiye adresli uluslararası yayınlarda yaşanan artışın beraberinde ortak yazarlı çalışmaları da arttırdığını, buna karşın bu çalışmalarda etnik iş birliklerinin ağır bastığını da göstermektedir. Yanı sıra Türkiye adresli yayınlarda son yıllarda metodolojik bir dönüşümün başladığı ve ilerleyen zamanlarda konu bakımından çeşitliliğin artacağı görülmektedir. Çalışma turizm alanyazındaki akademik üretim ve gelişim bakımından kapsamlı sonuç ve öneriler sunmaktadır
The Applicable Law to Proprietary Issues on Digital Assets Considering Recent Developments: Lex Rei Sitae or Not?
No full textThe legal nature of digital assets and the applicable law for digital assets have been debated in recent years in many legal systems, including Turkish law. The inability to reach a definite conclusion on evaluating the legal nature of digital assets in Turkish law makes it difficult to determine the applicable law to proprietary issues on digital assets in private international law. In the context of conflict of laws rules, determining the applicable law for rights over digital assets depends more on the medium in which the asset is recorded than its function. National legislators and legal institutions are seeking new connecting factors beyond the traditional lex rei sitae principle, given that digital assets predominantly exist in electronic environments. Therefore, our study aims to address how to bridge the gap in Turkish private international law concerning the applicable law for digital asset proprietary issues by drawing on comparative law developments. © 2025 Elsevier B.V., All rights reserved
Efficient QCA-Based Circuits for Low-Power Medical IoT System
No full textThe Internet of Things (IoT) plays a vital role in the recent healthcare industry by providing precise diagnostic and treatment capabilities. There is a growing interest in medical IoT incorporated into healthcare systems. The processing unit of all medical IoT comprises complementary metal-oxide semiconductor (CMOS) technology. However, CMOS Medical IoT technology has become integrated into biomedical hardware systems at the nanoscale regime. Due to regulatory, ethical, and technological challenges, including slow processing speeds, high power consumption, and slow switching frequencies, particularly in the gigahertz (GHz) range. On the other hand, compared to traditional computers, quantum technology will accelerate processing by an order of magnitude and affect all artificial and medical (AI) and medical IoT processing applications. Quantum-dot cellular automata (QCA) present a promising alternative digital hardware system in medical IoT. QCA technology makes an optimal choice for establishing circuit design frameworks for AI in medical IoT applications, where low-cost, real-time, energy-efficient performance is crucial. Moreever, encryption and decryption circuits have been used in medical IoT operations to protect sensitive patient data while it is being transmitted and stored. The essential arithmetic and logic unit (ALU) is proposed in this context, which is the foundation for processing and computational units for medical IoT systems at the nanoscale devices. A systematic approach is involved in integrating adders, multiplexers, an ALU, and a logic unit to enhance processor drive and privacy via encryption and decryption in medical IoT. The experimental outcomes reveal that the recommended design overtakes the previous design by 15.48 % in terms of cells and 16.07 % in terms of area. The designs are accurately simulated using the QCADesigner-E 2.0.3 software tool
The Private Equity Industry in Africa: Firm Survival and Growth
No full textTogan, Asli/0000-0003-0489-6855The availability of Private Equity (PE) in Africa is quite limited. And even though the literature documents that in other parts of the world, this type of financing can relieve entrepreneurial firms' financial constraints and likely benefit employment and firm growth, little is known about the effect of PE on firms operating in Sub-Saharan Africa (SSA). This paper describes the landscape of PE in this region and analyzes whether private equity helps firms survive and grow. The results reveal that recipients of external financing from PE firms have a higher probability of survival than non-recipients, and such financing strongly correlates with proxies for firm growth. These results remain robust in a further attempt to alleviate endogeneity, using propensity score matching to estimate the difference in outcomes between recipients and non-recipients. Our results suggest that PE is an essential source of external financing for SSA firms and that governments should create incentives for investors and entrepreneurs.Emerging Sources Citation Inde
Priority-Based Sensing Strategy for ISAC Systems with Primary and Secondary Targets
No full textIntegrated sensing and communication (ISAC) holds significant commercial potential in future 6G. The 3GPP technical report indicates that it is crucial to prioritize the sensing services of the ISAC system to ensure the efficient execution of critical services due to resource-constrained environments. Thus, this paper investigates priority-based resource allocation in ISAC systems, where an ISAC base station (BS) simultaneously serves a communication user (CU) and detects both a primary sensing target (PST) and a secondary sensing target (SST). First, A priority criteria for this ISAC system is proposed: 1) Above all, to ensure that the Cramer-Rao bound (CRB) for PST is maintained below a threshold; 2) Following this, the CRB of the SST should be optimized, while ensuring the communication spectral efficiency is preserved. Then, based on this criterion, three cases are derived, and for each case, a distinct resource allocation problem is formulated, yielding closed-form or semi-closed-form expressions of the optimal resource allocation for each problem. Furthermore, An algorithm is also proposed to determine the occurrence of each case and provide the corresponding optimal resource allocation. In addition, system performance under each case is analyzed based on these expressions. Finally, the simulation results demonstrate the impact of the priority strategy on performance, which is consistent with the previous performance analysis.NSFC project [62020106001, 62361136810, 62271419, U2268201, U23A20274, 62301457]; Bilateral Scientific Cooperation Program with the China National Science Foundation (NSF), China; Scientific and Technical Research Council of Turkiye (TUBITAK), Turkiye [123N805]; National Key Laboratory of Wireless Communications Foundation [IFN202407]The work was supported in part by NSFC project under Grant U23A20274, Grant 62301457, Grant 62020106001, Grant 62361136810, Grant 62361136810, Grant 62271419 and Grant U2268201; in part by Bilateral Scientific Cooperation Program with the China National Science Foundation (NSF), China, and the Scientific and Technical Research Council of Turkiye (TUBITAK), Turkiye under Grant 123N805; in part by the National Key Laboratory of Wireless Communications Foundation under Grant IFN202407
Decolonizing Memory: New Animist and Relational Imaginaries in South Africa through Pamela Phatsimo Sunstrum’s Art and Koleka Putuma’s Poetry
No full textThis article draws on the works of Nurit Bird-David, Graham Harvey, Tim Ingold, and others to argue that new animism, with its emphasis on relational epistemologies, provides an ecological framework that reconfigures how we remember, relate, and resist. Through an analysis of the works of two contemporary South African artists—Pamela Phatsimo Sunstrum’s animist-infused paintings and Koleka Putuma’s relational poetry—the article demonstrates how new animist epistemologies can transform memory work in decolonized forms. Both artists engage with the afterlives of colonialism and apartheid in South Africa, revealing that relationships are not static but emerge continuously through interactions with the earth, matter, and spirit. Their work highlights how decolonization is not only geographically situated but also shaped by broader ecological contexts. By rethinking memory, identity, and resistance through the lens of new animism, this article showcases its potential to challenge and reshape postcolonial narratives. © 2025 Elsevier B.V., All rights reserved.Emerging Sources Citation Inde
Educational Researchers’ Perceptions of Editorial Ethics and Attitudes in Turkish Academic Journals: A Mixed-Methods Study
No full textThis study aimed to determine editors’ attitudes toward the article publication process in educational journals. A convergent mixed-methods design was employed to achieve this. Data were collected from 179 faculty members working in the education faculties in Turkey. The data collection instruments included the Editorial Attitudes Assessment Scale, a questionnaire on demographic characteristics, and an open-ended question soliciting additional opinions on the subject matter. The results of the descriptive and comparative analyses were compared, interpreted, and integrated with the findings obtained from the supplementary views provided by the participants. The authors contend that there are significant ethical shortcomings in the editorial practices. To enhance awareness of the role, responsibilities, and scientific and social obligations of editors in the article publication process, editorial training, orientation, and incentives for editing can be implemented. © The Author(s) 2025.Emerging Sources Citation Inde
Sarcasm Detection on News Headlines Using Transformers
No full textSarcasm poses a linguistic challenge due to its figurative nature, where intended meaning contradicts literal interpretation. Sarcasm is prevalent in human communication, affecting interactions in literature, social media, news, e-commerce, etc. Identifying the true intent behind sarcasm is challenging but essential for applications in sentiment analysis. Detecting sarcasm in written text, as a challenging task, has attracted many researchers in recent years. This paper attempts to detect sarcasm in news headlines. Journalists prefer using sarcastic news headlines as they seem much more interesting to the readers. In the proposed methodology, we experimented with Transformers, namely the BERT model, and several Machine and Deep Learning models with different word and sentence embedding methods. The proposed approach inherently requires high-performance resources due to the use of large-scale pre-trained language models such as BERT. We also extended an existing news headlines dataset for sarcasm detection using augmentation techniques and annotating it with hand-crafted features. The proposed methodology could outperform almost all existing sarcasm detection approaches with a 98.86% F1-score when applied to the extended news headlines dataset, which we made publicly available on GitHub.Graduate school of Isik UniversityThanks to the Graduate school of Isik University for their support