Muni Repository (MR)

This repository contains open access publications of Muni University Library.


Objectives:

  • To digitally collect, preserve and provide electronic access to scholarly works and research output of Muni University.
  • Increase the visibility and impact of our research, making it easy for researchers, students, policymakers and journalists to reference, replicate, and re-use the work.
  • Issue permanent, unique and trustworthy identifiers when creating URLs to access the resource without concern that the location of the resource may change.

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Recent Submissions

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Adaptation and carry over effects of extreme sporadic heat stress in Culex mosquitoes
(Elsevier, 2024-10-09) Padde, John Roberts; Zhou, Yinghui; Chen, Yunxuan; Zhu, Yuxiao; Yang, Yuxuan; Hou, Min; Chen, Lu; Xu, Zhipeng; Zhang, Donghui; Chen, Lin
Mosquitoes, as temperature-sensitive ectothermic vectors, exhibit temperature-dependence. This study investigates Culex pipiens pallens (Cx. pallens) responses to abrupt temperature increases and their implications on mosquito physiology. First instar larvae (24hr post hatching) and newly enclosed adults (24hr post emergence) were separately exposed to heat shock regimes of 33 °C, 37 °C, and 42 °C for 3 days alongside a control temperature of 27 °C. Results showed that mortality was triggered at 42 °C within a day. Adult male mosquitoes were less tolerant to all temperatures than larvae and adult females (p < 0.05). Exposing larvae to constant temperatures for 3 days significantly decreased larvae's development time, growth rate and adult emergence (p < 0.05). Reproductive fitness was significantly reduced (p < 0.05) in males emerging from larvae exposed to 37 °C. Life table parameters showed significant increased mortality rate, kill power and decreased life expectancy at the embryonic stage (p < 0.05). Furthermore, heatwaves deactivated the Transient receptor protein ankyrin 1 at 37 °C (p < 0.05) in larvae but not adults. Calmodium, Heat shock protein 90, and small heat shock protein expression were significantly decreased in larvae at 37 °C (p < 0.05) as compared to larvae raised at 33 °C and 27 °C. In conclusion, we classified the heat waves into three categories: adaptable (33 °C), critical (37 °C), and fatal (42 °C). Prolonged exposure of Culex pallens larvae to extreme heat affects the male reproductive output. These findings may serve as an important reference for forecasting vector and pest dynamics and used to tailor mosquito prevention and control measures.
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Novel anti-inflammatory peptide alleviates liver ischemia-reperfusion injury
(Journal of Biomedical Research, 2024-04-30) Xu, Xuejun; Sun, Kaineng; Chang, Hao; Shen, Chunxiang; Li, Xiangdong; Ni, Yangyue; Zhu, Yuxiao; Wang, Huiquan; Xiong, Ruiyan; Padde, Jon Rob; Xu, Zhipeng; Chen, Lin; Chen, Lu; Hou, Min; Pu, Liyong; Ji, Minjun
Ischemia-reperfusion injury (IRI) remains inevitable in liver surgeries, macrophages play a critical role in the development of IRI, but little is known about the macrophages regulate pathogenesis of IRI. Based on target guided screening, we identified a small 3 kDa peptide (SjDX5-271) from various schistosome egg-derived peptides that induced M2 macrophage polarization. SjDX5-271 treatment protected the mice against liver IRI through promoting M2 macrophage polarization, the protective effect was abrogated when the macrophages were depleted. Transcriptomic sequencing showed that the TLR signaling pathway was significantly inhibited in macrophages derived from the SjDX5-271 treatment group. We further identified that SjDX5-271 promotes M2 macrophage polarization by inhibiting the TLR4/MyD88/NF-κB signaling pathway and further alleviates hepatic inflammation in liver IRI. Collectively, SjDX5-271 exhibits promising therapeutic effects in IRI and represents a novel therapeutic approach for IRI, even in immune-related diseases. This study revealed the development of a new biologic from the parasite and enhanced our understanding of host-parasite interplay, providing a blueprint for future therapies for immune-related diseases.
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Evaluation of corrosion performance of LDX 2101 and UNS S32205 in flexible pipeline applications: A comparative study
(Journal of Engineering Research and Reports, 2024-09-24) Gumoshabe, Michael; Opio, Innocent M.; Makanga, Jackson; Kule, Saimon; Ongom, Douglas
Lean duplex stainless steel (LDSS) has been used in various applications, including flexible pipelines in offshore and other industrial settings. In recent years, LDSS has become the preferred choice over standard duplex stainless steel (DSS) for flexible pipeline applications due to its lower costs, achieved by reducing nickel and molybdenum content, while still providing comparable corrosion resistance and mechanical strength properties to DSS. However, there is still limited reporting on the corrosion effects of reducing these alloys on the behaviour of lean duplex stainless steel in flexible pipelines. This comparative study investigates the corrosion resistance of lean duplex stainless steel, LDX 2101 and duplex stainless steel, UNS S32205 in flexible pipeline applications using linear polarization resistance (LPR). The research focuses on assessing material performance in environments containing CO2 and H2S, commonly found in oil and gas production, by conducting short-term and long-term tests to evaluate pitting and selective corrosion. The samples, LDX 2101 and UNS S32205 were immersed in a 3.5M NaCl solution, and corrosion measurements were performed using the Metrohm Autolab potentiostat. The results indicate that both materials exhibit good corrosion resistance, but there are differences in their performance under specific conditions. While lean duplex stainless steel, LDX 2101, can be used as a substitute for duplex stainless steel UNS S32205, its corrosion resistance and mechanical properties gradually decrease over time due to the reduced nickel and molybdenum content. As a result, it would not be as effective as duplex stainless steel UNS S32205 in withstanding corrosion in aggressive conditions over a prolonged period.
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Next generation sequencing and genetic analyses reveal factors driving evolution of sweetpotato viruses in Uganda
(MDPI, 2024-09-26) Adero, Joanne; Wokorach, Godfrey; Stomeo, Francesca; Yao, Nasser; Machuk, Eunice; Njuguna, Joyce; Byarugaba, Denis K.; Kreuze, Jan; Yencho, G. Craig; Otema, Milton A.; Yad, Benard; Kitavi, Mercy
Sweetpotato (Ipomoea batatas L.) is an essential food crop globally, especially for farmers facing resource limitations. Like other crops, sweetpotato cultivation faces significant production challenges due to viral infections. This study aimed to identify and characterize viruses affecting sweetpotato crops in Uganda, mostly those associated with sweetpotato virus disease (SPVD). Infected leaf samples were collected from farmers’ fields in multiple districts spanning three regions in Uganda. MiSeq, a next-generation sequencing platform, was used to generate reads from the viral nucleic acid. The results revealed nine viruses infecting sweetpotato crops in Uganda, with most plants infected by multiple viral species. Sweet potato pakakuy and sweet potato symptomless virus_1 are reported in Uganda for the first time. Phylogenetic analyses demonstrated that some viruses have evolved to form new phylogroups, likely due to high mutations and recombination, particularly in the coat protein, P1 protein, cylindrical inclusion, and helper component proteinase regions of the potyvirus. The sweet potato virus C carried more codons under positive diversifying selection than the closely related sweet potato feathery mottle virus, particularly in the P1 gene. This study provides valuable insights into the viral species infecting sweetpotato crops, infection severity, and the evolution of sweet potato viruses in Uganda.
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Structural equation model for a relationship between family support systems and alcohol addiction recovery: mediation effect of continuing care services.
(Journal of Advanced Psychology, 2024-08-09) Kyazze, Richard; Natuhamya, Charles; Mwebesa, Edson; Kiyingi, Frank; Musoke, Miph; Tumwesigye, Nazarius Mbona
Purpose: Alcohol use disorder continues to be a public health concern, and even after treatment, the relapse rate is still high. The family support systems are closely related to alcohol addiction recovery. However, studies on psychological mechanisms between the two are rare. Therefore, we aimed to explore the mediating role of continuing care services in the pathway between family support systems and alcohol addiction recovery among individuals with alcohol use disorder. Methods: A total of 196 participants from 5 treatment centers (Butabika National Referral Mental Hospital, Serenity Centre, Recovery Solutions, National Care Centre, and Hope and Beyond) were selected from a target population of 400 individuals. The structural equation modeling approach was used to assess the study objective. Results: The average alcohol addiction recovery status score was 3.03 (SD = 0.95). The mediation analysis indicated that continuing care services mediated the pathway between family support systems and alcohol addiction recovery. Unique Contribution to Theory, Practice and Policy: Motivational enhancement therapy, mutual health support, and cognitive behavioral therapy are key factors in the relationship between family support systems and alcohol addiction recovery.