Ecology of <i>Cryptococcus neoformans</i> in Vietnam

Cryptococcal meningitis is an infection with Cryptococcus species; almost all disease occurs in immunosuppressed patients due to C. neoformans. Cryptococcus spp are environmental saprophytes; the ability to cause disease is considered an accident of adaptation to their ecological niche. In Southeast Asia, cryptococcal meningitis in immunocompetent individuals is well-described and is almost always due to the C. neoformans ST5 (VNIa-5) lineage. I hypothesize this lineage has relative increased pathogenicity. The aims of this thesis were to: identify the ecological niche of C. neoformans; define the diversity of C. neoformans in Vietnam; compare the virulence of different genotypes, and; define transcriptional differences associated with virulence. I identified spatial clustering of lineages VNIa-4, VNIa-5 and VNIa-32. Environmental sampling yielded 123 cryptococci the majority of which were non-pathogenic. Using the G. mellonella infection model I identified an ‘ecological imprint’ on isolates. Within a lineage, the virulence of an isolate is determined by its source – environmental, immunosuppressed or immunocompetent patient. Moreover, the virulence of environmental C. neoformans can be upregulated by clinical strains of that lineage. This ‘induction’ effect is regulated by a protein/peptide signaling system. Comparative transcriptomics revealed 1700 genes differentially expressed between clinical and environmental isolates. Gene ontology (GO) terms relevant to metabolism and cellular biosynthesis were enriched in clinical isolates; GO terms relevant to cell cycle and cell division were significantly enriched in induced environmental isolates. Clinical and induced environmental isolates had highly similar transcriptomes. A number of genes previously confirmed as virulence determinants were upregulated in clinical and induced environmental isolates; a third of differentially expressed genes between the induced and `naive' isolates were hypothetical proteins. These are novel candidates implicated in the upregulation of virulence. My findings provide insight into ecology of C. neoformans in Vietnam and the genetic control of virulence

Enriching Biomedical Knowledge for Vietnamese Low-resource Language Through Large-Scale Translation

Biomedical data and benchmarks are highly valuable yet very limited in low-resource languages other than English such as Vietnamese. In this paper, we make use of a state-of-the-art translation model in English-Vietnamese to translate and produce both pretrained as well as supervised data in the biomedical domains. Thanks to such large-scale translation, we introduce ViPubmedT5, a pretrained Encoder-Decoder Transformer model trained on 20 million translated abstracts from the high-quality public PubMed corpus. ViPubMedT5 demonstrates state-of-the-art results on two different biomedical benchmarks in summarization and acronym disambiguation. Further, we release ViMedNLI - a new NLP task in Vietnamese translated from MedNLI using the recently public En-vi translation model and carefully refined by human experts, with evaluations of existing methods against ViPubmedT5

Improved particle swarm optimization algorithms for economic load dispatch considering electric market

Economic load dispatch problem under the competitive electric market (ELDCEM) is becoming a hot problem that receives a big interest from researchers. A lot of measures are proposed to deal with the problem. In this paper, three versions of PSO method such as conventional particle swarm optimization (PSO), PSO with inertia weight (IWPSO) and PSO with constriction factor (CFPSO) are applied for handling ELDCEM problem. The core duty of the PSO methods is to determine the most optimal power output of generators to obtain total profit as much as possible for generation companies without violation of constraints. These methods are tested on three and ten-unit systems considering payment model for power delivered and different constraints. Results obtained from the PSO methods are compared with each other to evaluate the effectiveness and robustness. As results, IWPSO method is superior to other methods. Besides, comparing the PSO methods with other reported methods also gives a conclusion that IWPSO method is a very strong tool for solving ELDCEM problem because it can obtain the highest profit, fast converge speed and simulation time

Occupational Safety Practice of Hazardous Health-care Waste Management in Bengkulu City

Background: Facing many patients while the workers were limited prompted health workers to make a quick decision regarding health-care waste. High workload pressured health workers and put them at risk of getting diseases than others, especially diseases from medical waste that they took care. Besides, as health workers, they should be clean from bacteria or viruses that can transmit  diseases to their patients. This research aimed to investigate the factors associated with occupational safety practice of hazardous health-care waste management in Bengkulu City. Method: This cross-sectional study used a stratified random sampling technique to select 230 respondents who work as health workers to respond to a questionnaire interview. The data were analyzed using multivariate logistic regression to find the association between the outcomes and the independent variables. Results: The prevalence of   poor  occupational safety practice of hazardous health-carewaste management was 35.21 % (95% CI = 29.27-41.66).  The factors significantly associated with occupational safety practice of hazardous health-care waste management were; gender (p-value &lt; 0.001), department/unit (p-value &lt; 0.001), knowledge (p-value &lt; 0.001), and spirituality (p-value  &lt; 0.001). Conclusion:  gGnder, department/unit, knowledge, and spirituality were associated with occupational safety practice of hazardous health-carewaste management in Bengkulu City

Minimize the load reduction considering the activities control of the generators and phase distance

This study shows how to calculate the minimum load that needs to be reduced to restore the frequency to the specified threshold. To implement this problem, the actual operation of the electricity system in the event of a generator outage is considered. The main idea of this method is to use the power balance equation between the generation and the load with different frequency levels. In all cases of operating the electrical system before and after the generator outage, the reserve capacity of other generators is considered in each generator outage situation. The reduced load capacity is calculated based on the reciprocal phase angle sensitivity or phase distance. This makes the voltage phase angle and voltage value quality of recovery nodes better. The standard IEEE 9-generator 37-bus test scheme was simulated to show the result of the proposed technique

Gravity terrain correction for mainland territory of Vietnam

Terrain corrections for gravity data are a critical concern in rugged topography, because the magnitude of the corrections may be largely relative to the anomalies of interest. That is also important to determine the inner and outer radii beyond which the terrain effect can be neglected. Classical methods such as Lucaptrenco, Beriozkin and Prisivanco are indeed too slow with radius correction and are not extended while methods based on the Nagy’s and Kane’s are usually too approximate for the required accuracy. In order to achieve 0.1 mGal accuracy in terrain correction for mainland territory of Vietnam and reduce the computing time, the best inner and outer radii for terrain correction computation are 2 km and 70 km respectively. The results show that in nearly a half of the Vietnam territory, the terrain correction values ≥ 10 mGal, the corrections are smaller in the plain areas (less than 2 mGal) and higher in the mountainous region, in particular the correction reaches approximately 21 mGal in some locations of northern mountainous region. The complete Bouguer gravity map of mainland territory of Vietnam is reproduced based on the full terrain correction introduced in this paper

Privacy-Preserving Digital Vaccine Passport

The global lockdown imposed during the Covid-19 pandemic has resulted in significant social and economic challenges. In an effort to reopen economies and simultaneously control the spread of the disease, the implementation of contact tracing and digital vaccine passport technologies has been introduced. While contact tracing methods have been extensively studied and scrutinized for security concerns through numerous publications, vaccine passports have not received the same level of attention in terms of defining the problems they address, establishing security requirements, or developing efficient systems. Many of the existing methods employed currently suffer from privacy issues. This work introduces PPass, an advanced digital vaccine passport system that prioritizes user privacy. We begin by outlining the essential security requirements for an ideal vaccine passport system. To address these requirements, we present two efficient constructions that enable PPass to function effectively across various environments while upholding user privacy. By estimating its performance, we demonstrate the practical feasibility of PPass. Our findings suggest that PPass can efficiently verify a passenger’s vaccine passport in just 7 milliseconds, with a modest bandwidth requirement of 480KB

Enhancement of flow boiling heat transfer in microchannels by nano- and micro-surface treatments

This work investigates the flow boiling heat transfer in microchannels with the aim of developing compact cooling systems which can be adapted to miniaturized power components. Nano and micro-surface treatments were used as innovative techniques to improve the heat transfer performance as well as to delay the intermittent dryout. It was observed that the micro-structured surfaces show significant enhancements (up to 85%) in heat transfer compared to the smooth surfaces. Especially, using the highly-wetted structured surface, the intermittent dryout is improved

Application of AHP algorithm on power distribution of load shedding in island microgrid

This paper proposes a method of load shedding in a microgrid system operated in an Island Mode, which is disconnected with the main power grid and balanced loss of the electrical power. This proposed method calculates the minimum value of the shed power with reference to renewable energy sources such as wind power generator, solar energy and the ability to control the frequency of the generator to restore the frequency to the allowable range and reduce the amount of load that needs to be shed. Computing the load importance factor (LIF) using AHP algorithm supports to determine the order of which load to be shed. The damaged outcome of load shedding, thus, will be noticeably reduced. The experimental results of this proposed method is demonstrated by simulating on IEEE 16-Bus microgrid system with six power sources