Diagnosis of tuberculosis in a high burden resource limited setting

It is estimated that over nine million new tuberculosis (TB) cases worldwide occurred in 2009. However, only 63% of these cases were notified, which is lower than the 75% target set by the DOTS strategy. The lack of ideal diagnostic tests is one of the major barriers to effective TB reduction. The aim of this thesis is to evaluate the efficiency of a novel liquid culture based technique (Microscopic Observation Drug Susceptibility Assay-MODS) and a new generation fluorescence microscope (Light Emitting Diodes fluorescence microscope - LED fluorescence microscope) in diagnosis of TB and multi drug resistant tuberculosis (MDR- TB) in Viet Nam, a resource limited, high burden setting. In the studies described in this thesis, MODS had a higher sensitivity than homogenous smear microscopy, detecting an additional 13% of cases, in diagnosis of TB. Importantly, the pooled sensitivity of MODS (53.0%) was comparable to that of Mycobacteria Growth Indicator Tube technique (MGIT) (57.8%) with clinical presentation as the gold standard. In terms of multi drug resistant tuberculosis (MDR- TB) diagnosis, MODS had rather low sensitivity in detection of Isoniazid (INH) or Rifampicin (RIF) resistant and MDR isolates, 72.6%, 72.7% and 77.8%, respectively against the proportional drug susceptibility testing (DST) method. The low sensitivity of DST-MODS in this study was probably due to low bacterial load samples and use of a high INH critical concentration (O.4~g/ml). For LED microscopy, the detection rate, sensitivity, specificity and false negative of LED 40X were comparable to those of conventional fluorescence microscope and light microscope. The false positive rate • of LED 40X increased in comparison with Ziehl-Neelsen (ZN) reading in the early phases of the evaluation (2.6% and 2.7% vs 0% in the validation and implementation phases vs continuation phase, respectively), probably due to lack of experience among technicians, but no significant difference was found (P>0.05). In the last phase, no false positive result was recorded. Although the reading time of fluorescence-LED (FM-LED) and ZN reading were less than 2 minutes, ZN-light microscope (ZN-LM) reading time was shorter than that of FM-LED40X, especially in positive smears (P=0.007) in the early study phase. By the end of the study, FM-LED reading time was shorter than ZN-LM which was recorded in the early phase. With high experienced technicians there may be little or no additional benefit to case detection if a light microscope is replaced by a fluorescence microscope. In general, MODS and LED microscopy are reliable methods for use in diagnosis of TB in resource limited settings due to their accuracy, reliability and low costs. Large scale operational projects should be conducted to evaluate the feasibility and cost-effectiveness of these methods in countries where these techniques are to be implemented

Strict partitions and discrete dynamical systems

AbstractWe prove that the set of partitions with distinct parts of a given positive integer under dominance ordering can be considered as a configuration space of a discrete dynamical model with two transition rules and with the initial configuration being the singleton partition. This allows us to characterize its lattice structure, fixed point, and longest chains as well as their length, using Chip Firing Game theory. Finally, we study the recursive structure of infinite extension of the lattice of strict partitions

The Impact of FDI, International Trade, and National Economy on People’s Standard of Living in ASEAN Countries

This research paper analyzes the impact of foreign direct investment (FDI), international trade, and national economy on the standard of living of people in ASEAN member countries, using data from 2012-2021. The study uses data from this period to examine the effects of these variables on the standard of living in ASEAN member countries. The results indicate that international trade and national economy have a significant influence on people's standard of living in the region. However, the effect of FDI varies depending on the level of development of the country. While FDI doesn't have much effect on developing countries, it has a negative impact on developed countries. The study also provides insights for policymakers on how to promote economic growth and improve the quality of life for people in the ASEAN. Keywords: FDI, international trade, national economy, the standard of living, ASEAN DOI: 10.7176/EJBM/15-6-10 Publication date:March 31st 2023

EFL STUDENT’S PROBLEMS WITH PARAGRAPH WRITING AT TAY DO UNIVERSITY, VIETNAM

This paper studied problems in EFL students’ paragraph writing. The research participants were first-year students of English in Tay Do University (TDU). To achieve the desired aims of the current study, the researcher combined both qualitative and quantitative methods, using questionnaires, interviews, and observations as the main instruments. The researcher used the package of social sciences (SPSS) for analysis. Research results showed that the freshmen at TDU often encountered problems in writing paragraphs. These accounted for grammatical structures, vocabulary, and coherence. Basing on the research results, students could recognize their difficulties when writing and find some new ways to overcome them. It is suggested that teachers should find and update some new teaching methods so as to develop students’ paragraph writing skills. Article visualizations

Isolation an agar degradation Bacillus sp. AT6 and preliminary application for seaweed saccharification

Background: Agar is a common polysaccharide found in nature. However, agar is strongly resisted to the degradation processing, leading to limitation of its application in various areas. Thus, finding an effective solution for agar saccharification significantly improves the economically effects of agar based substrates.Methods: Soil samples were collected from TienPhong Forestry Ltd. Company, ThuyXuan District, ThuaThien Hue province, Vietnam. Potential agar degrading bacteria were screened on a mineral salt agar medium. The isolate was identified based on 16S rRNA nucleotide sequence, morphological, physiological, and biochemical characteristics. Agarase production was evaluated by modification culture conditions including incubation time, shaking speed, and initial inoculum size. Molecular mass of extracellular agarase was determined by native SDS-PAGE. The effect of pH, temperature, metal ions, and organic solvents were conducted for enzyme characterization. Application of enzyme was investigated on seaweed saccharification.Result: An agar degrading bacterial strain was isolated from soils and identified as Bacillus sp. AT6. Maximal agarase accumulation obtained in the culture containing an inoculum size of 10% (v/v), shaking speed of 210 rpm, and 96 hours incubation. The agarase revealed a single band on zymogram analysis with an apparent molecular weight of 180 kDa. The optimal temperature and pH were 40°C and pH 8.0, respectively. All tested metal ions and organic solvents partially decreased enzyme activity. Treatment seaweed by agarase resulted in reducing sugars release present in the reaction, indicating the saccharification of seaweed was succeeded.Conclusion: Bacillus sp. AT6 is a new report of agarolytic bacteria that produces extracellular agarase enzymes. The present results promise strain AT6 is a great candidate for agar saccharification for industrial application

Preschool STEM Activities and Associated Outcomes: A Scoping Review

This review highlights the need for further investigation into the benefits of STEM activities in preschool children’s learning, girls’ engagement and learning of children with disabilities in the STEM field. The review process involved accessing 19 relevant studies from Scopus, ERIC and Google Scholar databases in March 2023. Through the synthesis of information from these studies, seven STEM activities were identified as effective in enhancing preschool children’s learning: educational robots, educational games, argumentative interactions, inquiry-based learning and engineering design, drawing and telling about engineers, free play and pretend play, and group membership. Each of these activities contributes to different learning outcomes for children. Moreover, the review emphasizes the importance of role-playing activities ‘as if’ engineers and scientists, facilitated by teachers, in fostering girls’ motivation and engagement in the STEM field from an early age. Long-term scientific interventions at home have a significant positive impact on the science literacy skills of deaf children. The implications of this review are particularly relevant for early childhood educators, as it provides valuable insights into the use of STEM activities to enhance children’s learning outcomes

Mediating Effect of Social Commerce Continuance Use Intention on the Relationship Between Perceived Values and Brand Loyalty

The purpose of this paper is to examine the mediating effect of social commerce continuance use intention on the relationship between perceived values and brand loyalty in the social commerce context. The data was collected from 176 members of the Apple Watch Social Commerce site in Vietnam via an online questionnaire. Applying the structural equation modelling method, we found that social commerce continuance use intention has mediating effects on the relationship between perceived values and brand loyalty. Keywords: Perceived values, continuance use intention, brand loyalty, social commerce, Vietnam DOI: 10.7176/EJBM/12-11-07 Publication date: April 30th 202

Decreasing behavior of the depth functions of edge ideals

Let $I$ be the edge ideal of a connected non-bipartite graph and $R$ the base polynomial ring. Then $\operatorname{depth} R/I \ge 1$ and $\operatorname{depth} R/I^t = 0$ for $t \gg 1$. We give combinatorial conditions for $\operatorname{depth} R/I^t = 1$ for some $t$ in between and show that the depth function is non-increasing thereafter. Especially, the depth function quickly decreases to 0 after reaching 1. We show that if $\operatorname{depth} R/I = 1$ then $\operatorname{depth} R/I^2 = 0$ and if $\operatorname{depth} R/I^2 = 1$ then $\operatorname{depth} R/I^5 = 0$. Other similar results suggest that if $\operatorname{depth} R/I^t = 1$ then $\operatorname{depth} R/I^{t+3} = 0$. This a surprising phenomenon because the depth of a power can determine a smaller depth of another power. Furthermore, we are able to give a simple combinatorial criterion for $\operatorname{depth} R/I^{(t)} = 1$ for $t \gg 1$ and show that the condition $\operatorname{depth} R/I^{(t)} = 1$ is persistent, where $I^{(t)}$ denotes the $t$-th symbolic powers of $I$.Comment: 15 pages, 3 figure