215 research outputs found
Multilevel determinants of children's health outcomes
Background: Children’s health, particularly in the early years, forms the basis of future health and development and plays a significant role in predicting individual life and opportunities. Thus, studies which enhance the understanding of the determinants of children’s health status are needed. Previous research on children’s health had focused on the family’s and infant’s characteristics and ignored the potential impact of macro-level influences. The objectives of this thesis were (i) to examine the independent effects of neighbourhood factors on childhood health outcomes, (ii) to explore neighbourhood moderating effects on the associations between some individual risk factors and childhood health outcomes, and (iii) to quantify the contribution of neighbourhood factors to childhood health outcomes.Method: The study population included 9,888 children born to women residing in Saskatoon during three years, 1992-1994. The data used in this study were extracted from three sources. The information related to birth outcomes and the mother’s characteristics was extracted from the birth registration files maintained by Saskatchewan’s Vital Statistics Branch. The health services utilization information was generated from Saskatchewan Health’s computerized administrative databases. The information related to the neighbourhood characteristics was obtained from Statistics Canada’s 1991 Census, from local sources such as the Planning Department of the City, and two specialized neighbourhood surveys. Six domains of neighbourhood were examined in this study: socio-economic disadvantage, social interaction, physical condition, population density, local programs and services, and unhealthy lifestyle norm. This study was divided into two focused topics corresponding to two children’s health outcomes: low birth weight (LBW) and children’s hospitalizations (both incidence and length of stay). Multilevel modelling was employed to examine the independent/moderating impacts of neighbourhood characteristics on these children’s health outcomes. GIS mapping was used to visualize the associations between neighbourhood characteristics and children’s health outcomes.Findings of focused topic 1: There was a significant variation across Saskatoon neighbourhoods in the distribution of LBW rate. This significant variation was attributed to both the characteristics of individuals living within the neighbourhoods as well as the characteristics of the neighbourhood of residence. Neighbourhood variables were both independent risk factors for LBW and moderators for the association between maternal characteristics and LBW. Specifically, a greater level of socio-economic disadvantage, a lower level of program availability and accessibility within the neighbourhoods were associated with a higher risk of LBW. A significant interaction between neighbourhood social interaction and single parent status was found. The risk of single parent status on LBW was mitigated by a greater level of social interaction within neighbourhoods. With individual level variables held constant, three neighbourhood variables predicted LBW, together contributing to a change in LBW rate of 7.0%.Findings of focused topic 2: This focused topic employed a longitudinal/multilevel design to examine the effects of socio-economic status at multiple levels on children’s hospitalization. The key findings of this focused topic are the following: (i) There was a gradient association between the number of adverse birth outcomes and childhood hospitalization; (ii) There was a significant interaction between family income and adverse birth outcomes (i.e., the effect of adverse birth outcomes on childhood hospitalization was heightened among those children living in low income families); (iii) Neighbourhood characteristics, specifically neighbourhood socio-economic disadvantage, neighbourhood physical condition, and neighbourhood population density had independent effects on childhood hospitalization over and above the effect of family income; (iv) With individual level variables held constant, three neighbourhood variables (i.e., neighbourhood socio-economic disadvantage, physical condition and population density) together accounted for a variation of 40% in the incidence rate of hospitalization, and two neighbourhood variables (i.e., neighbourhood socio-economic disadvantage and physical condition) together accounted for a change in the length of stay per hospitalization from 2.88 days to 5.18 days across neighbourhoods.Conclusion: Both individual and neighbourhood characteristics determined childhood health outcomes examined. Neighbourhood factors acted as independent risk factors as well as moderators on the association between individual risk factors and health outcomes. The contribution of neighbourhood factors to children’s health outcomes was quite substantial. The findings suggest that future interventions aimed at improving children’s health status in Saskatoon may be enhanced by targeting both high risk individuals and high risk neighbourhoods. The geographical variations in children’s health outcomes reported in this study are modifiable; they can be altered through public policy and urban planning, and through the efforts of families and children
Limitations of cyclic pile load tests by kentledge system in soft clay soil
The paper describes the inadequacies of cycled head-down load tests on two barrettes and one bored pile installed in soft clay soil region in Binh Thanh district, and district 7, Ho Chi Minh City, Vietnam, respectively. The soil profile of these sites consisted of layers of organic soft clay and silt from 22.5 m to 28.6 m depth on compact silty sand or semi-stiff to stiff clays to about 60 m depth and followed by dense to very dense sand. The cross-section area of two barrettes located on the Tan Cang complex area was 2,800 mm by 800 mm, which were constructed using the bucket drill technique with bentonite slurry into 65 m depth. The bored pile of the Lakeside project in district 7 having a pile diameter was 1200 mm and 80 m depth. All instrumented piles were attached from ten to eleven strain gages levels along the pile shaft to record the deformation data during the load tests. The strain data analysis shows that the shaft frictions of pile portions located in the soft clay soil regions were increased dramatically, and the base resistances were smaller expected by the setting-up of Kentledge and the cyclic loading tests
Synthesis of ZnO nanorod for immunosensor application
This paper reported a facile method to synthesize ZnO nanorods for immunosensor application. The ZnO nanorods were synthesized by hydrothermal reaction. Synthesis time affecting on morphology of nanorods was also studied. The immobilization of anti-rotavirus onto ZnO nanorod-deposited sensor was performed via absorption method. The electrochemical responses of the immunosensor were studied by cyclic voltammetry (C-V) method with [Fe(CN)6]3−/4− as redox probe. A linear decreased response in C-V for cell of rotavirus concentration was found in the range of 7.8×105 CFU/mL to 7.8×108 CFU/mL. The detection limit of the immunosensor was 7.8×105 CFU/mL. The results indicated application of ZnO nanorod sensor for label-free real-time detection of a wide dynamics range of biological species
Financial depth and economic growth: Empirical evidence from ASEAN+3 countries
Nexus between financial depth and economic growth has been studied for long time and still attracts great attention from policymakers. This research examines the relationship among ASEAN+3 countries from 2000 to 2014 based on Cobb-Douglas theoretical framework. The results show that fi-nancial depths measured by domestic credit to private sector, M3 and stock market capitalisation all have significant effects on economic growth. The paper also gives policy recommendations to promote financial development for purposes of long-term economic growth in ASEAN+3 countries
Expression of gene encoding flavonol synthase isolating from trung du xanh tea (Camellia sinensis var. macrophylla) in E. coli
Common flavonols in plants including quercetin, kaempferol and myricetin are synthesized from dihydroflavonols (dihydroquercetin-DHQ, dihydrokaempferol-DHK and dihydromyricetin-DHM) by flavonol synthase (FLS). In tea, FLS has been shown to metabolize dihydroquercetin to quercetin. The FLS gene was cloned and sequenced from the cultivated tea (Camellia sinensis var. macrophylla) in Thai Nguyen province. In this study, we presented the results of optimizing and designing an expression vector for recombinant FLS (recombinant FLS-rFLS). The FLS gene was ligated completely to the pET32a (+) vector, then expressed in E. coli Rosetta1 and Rosetta2 strain. Using 1mM IPTG to induce the expression of rFLS at 37oC, rFLS was obtained with 52.83 kDa in size and existed predominantly as insoluble form. E. coli Rosetta1 pET32a (+)_FLSproduces rFLS in the soluble fraction than E. coli Rosetta2 pET32a (+)_FLS. Next, E. coli Rosetta1 pET32a (+)_FLSwas optimized for expression at temperatures of 30oC, 23oC and 16oC (24 and 48 hours). After being induced for expression with 1mM IPTG in 48 hours and cultured at 16oC, E. coli Rosetta1 strain containing pET32a (+) FLS produced the largest amount of rFLS in the soluble form.
Isolation and identification of indole acetic acid producing bacteria from the coasts of Ben Tre and Tra Vinh Provinces
Beneficial plant-growth-promoting bacteria (PGPB) have been reasonably applied to rescue crucial issue for agriculture by salinity soil. Observed most of PGPB was found in endophyte, rhizosphere and soil. Indole acetic acid (IAA)-producing bacteria could naturally stimulate and facilitate plant growth. The knowledge of IAA production and content of bacteria resident in the marine environment has been typically insufficient and limited to date. In recent years, unwarrantable intrusions of sea water have been enlarged in the Mekong River Delta of Vietnam, threatening productive rice fields, local fruits, and cash crops. Therefore, finding PGPB in the coastal regions in the Mekong River Delta as a creative resource for sustainable agriculture is necessary and is a prompt challenge. In this study, IAA-producing bacteria from coastal regions of Ben Tre and Tra Vinh Provinces were isolated and adequately identified. Out of 202 bacterial isolates, 10 isolates showed the possible ability to produce IAA from L-tryptophan. These 10 isolates were objectively evaluated the capacity to produce IAA under 5% (w/v) NaCl in King B and marine broths. The results revealed that IAA production decreased in 5% NaCl, even though bacterial growth increased. These 10 IAA-producing bacteria were classified at the species level, Marinobacter hydrocarbonoclasticus, M. pelagius, M. daepoensis, and Mameliella phaeodactyli by 16S rRNA gene analysis. The most IAA producer in King’s B broth, the isolate C7, was investigated in more detail. The isolate C7 produced the maximum IAA amount (192.2 ± 1.14 µg/ml) under the presence of 20 g/l yeast extract, 2 g/l of L-tryptophan and 1% NaCl. The isolate C7 was able to grow at 1–17% (w/v) NaCl (optimum, 4%), but not in the absence of NaCl, indicating it is a moderate halophilic bacteria. This study highlighted the considerable ability to produce IAA of marine bacteria, which could be thoughtfully considered to use naturally as biofertilizers to promote plant growth in saline intrusion lands.
Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16
Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.
Ecological and behavioural risk factors of scrub typhus in central Vietnam: a case‑control study
Background: The risk factors for scrub typhus in Vietnam remain unknown. Scrub typhus caused by Orientia tsutsugamushi often presents as an undifferentiated febrile illness and remains under appreciated due to the limited availability of diagnostic tests. This tropical rickettsial illness is increasingly recognized as an important cause of non-malaria acute undifferentiated fever in Asia. This study aimed to investigate behavioural and ecological related risk factors of scrub typhus to prevent this potentially life-threatening disease in Vietnam. Methods: We conducted a clinical hospital-based active surveillance study, and a retrospective residence-enrolment date-age-matched case-control study in Khanh Hoa province, Vietnam, from August 2018 to March 2020. Clinical examinations, polymerase chain reaction and enzyme-linked immunosorbent assay IgM tests were applied to define cases and controls. All enrolled participants filled out a questionnaire including demographic socio-economic status, personal behaviors/protective equipment, habitat connections, land use, and possible exposure to the vector. Multivariable conditional logistic regression was used to define the scrub typhus associated risk factors. Results: We identified 44 confirmed cases and matched them with 152 controls. Among cases and controls, the largest age group was the 41-50 years old and males accounted for 61.4% and 42.8%, respectively. There were similarities in demographic characteristics between the two groups, with the exception of occupation. Several factors were significantly associated with acquisition of scrub typhus, including sitting/laying directly on household floor [adjusted OR (aOR) = 4.9, 95% CI: 1.6-15.1, P = 0.006], household with poor sanitation/conditions (aOR = 7.9, 95% CI: 1.9-32.9, P = 0.005), workplace environment with risk (aOR = 3.0, 95% CI: 1.2-7.6, P = 0.020), always observing mice around home (aOR = 3.7, 95% CI: 1.4-9.9, P = 0.008), and use of personal protective equipment in the field (aOR = 0.4, 95% CI: 0.1-1.1, P = 0.076). Conclusions: Ecological and household hygiene-related factors were more associated with scrub typhus infection,than individual-level exposure activities in the hyper-endemic area. These findings support local education and allow people to protect themselves from scrub typhus, especially in areas with limitations in diagnostic capacit
MULTI-PIXEL PHOTON COUNTER FOR OPERATING A TABLETOP COSMIC RAY DETECTOR UNDER LOOSELY CONTROLLED CONDITIONS
The multi-pixel photon counter (MPPC) has recently emerged as a great type of silicon photomultiplier to replace or compensate for conventional vacuum-based photomultiplier tubes. An MPPC provides many advantageous features, such as high electrical gain, outstanding photon detection efficiency, fast timing response, immunity to magnetic fields, low-voltage operation, compactness, portability, and cost-effectiveness. This article examines the electrical and optical characteristics of an MPPC under loosely controlled environmental conditions. We also report a measurement of the light yield captured by the MPPC when a cosmic ray passes through the plastic scintillator, demonstrating that such a setup is suitable as a simple, cost-effective tabletop cosmic ray detector for educational and research purposes
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Beyond First/Last Mile Active Transportation - BikeShare@UH
Bike sharing is a new green transportation solution that has been developed and adopted at various cities around the world. In this paper, we present the process and results of the design and prototypes that a group of undergraduate students developed for a BikeShare@UH program during Summer 2017. After presenting the detailed results of four project teams focusing on customer discovery, bike share station (BSS) location identification, cloud-based mobile computing platform for user engagement and bike share program operation and management, smart lock, and alternative energy source based on PV panel. With the phase one implementation at the University planned in Spring 2018, we anticipate gathering real time data and feedback to improve the system.Cockrell School of Engineerin
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