44 research outputs found

    NGHIÊN CỨU CẤU TRÚC SÂU KHU VỰC ĐỨT GÃY SÔNG SÀI GÒN BẰNG PHƯƠNG PHÁP TỪ TELUA

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    This paper presents the magnetotelluric sounding results  of  Cu  Chi  -  Ben  Cat profile across the  Saigon  River fault. Results obtained by one-dimensional inversion of the data of a typical station located near the middle of the profile show that the geoelectric structure of the study area consists of three layers, in which the resistivities of the superficial and the underlying layers are relatively low compared with that of the intermediate layer. This geoelectric structure is then used to estimate the influence of the equatorial electrojet on the magnetotelluric measurements carried out in the region. Magnetotelluric forward problems were calculated and compared for cases of the present and the absent of the equatorial electrojet model. Results show that in the range of periods less than 0.7s, the apparent resistivity measured are not affected by the equatorial electrojet. Therefore, the apparent resistivity data measured in the period range less than 0.7s of all stations on the profile have been used for two-dimensional inversion to obtain geoelectric cross-section acrossing the Saigon River fault. The geoelectric cross-section down to a depth of 10km obtained by two-dimensional inversion shows a geoelectric structure consist of 3 layers: a low resistivity superficial layer, a resistive intermediate layer, and a low resistivity underlying layer. The superficial layer is clearly related to the sedimentary series. The intermediate layer may relate to the intrusive and consolidated rocks. The underlying layer may reflect conductive materials causing by high-temperature condition at depth. The interface between the intermediate and the underlying layers at around 3km depth corresponds probably to the crystalline basement. The low resistivity regions under the C4 and C2 stations may be related to the Duong Minh Chau - Dau Tieng - Can Gio and the Saigon River faults, correspondingly.ReferencesS. C. Constable, R. L. Parker, and C. G. Constable, 1987. Occam’ s inversion: A practical algorithm for generating smooth models from EM sounding data, Geophysics, 52, 289-300. H. Grandis, M. Menvielle, and M. Roussignol, 1999. Bayesian inversion with Markovchains-I. Themagnetotelluric one-dimensional case, Geophys. J. Int., 138, 757-768. Trương Quang Hảo, Lương Văn Trương, 2005. Xác định một vài thông số của dòng điện xích đạo ở Việt Nam, Tuyển tập báo cáo Hội nghị khoa học kỹ thuật địa vật lý Việt Nam lần thứ 4, 47-70. Trương Quang Hảo, 1997. Thành tựu nghiên cứu Vật lý Địa cầu 1987-1997. Trung tâm Khoa học Tự nhiên và Công nghệ Quốc Gia, viện Vật lý Địa cầu, Nxb. KHKT, 202-236. Nguyễn Ngọc Hoa (chủ biên), 1995. Bản đồ địa chất và khoáng sản Việt Nam, tỷ lệ 1:200.000, tờ C-48-XI, Thành phố Hồ Chí Minh, Cục Địa chất và Khoáng sản Việt Nam, Hà Nội. Đặng Văn Hưng, 1987. Tính chất của trường điện từ tự nhiên miền xích đạo từ và độ chính xác của của phương pháp MTS ở Việt Nam, Tạp chí các Khoa học về Trái Đất, T.9, 2, 61-66. A. G. Jones, 1992. Electrical conductivity of the continental lower crust, Continental lower crust, Edi. D. M. Fountain, R. J. Arculus and R. W. Kay, 81-143. S. K. Lee et al, 2009. MT2DinvMatlab-A program in MATLAB and FORTRAN for two-dimensional magnetotelluric inversion, Computers Geosciences, 35, 1722-1734. Đỗ Văn Lĩnh (chủ biên), 2009. Báo cáo thuyết minh đề tài “Phân vùng nhỏ động đất khu vực thành phố Hồ Chí Minh”, Sở Khoa học và Công nghệ thành phố Hồ Chí Minh, 248tr. Lê Huy Minh, Nguyễn Văn Giảng, Nguyễn Trọng Vũ và Lại Cao Khiêm, 2004. Kết quả sơ bộ nghiên cứu cấu trúc sâu vùng đồng bằng Sông Cửu Long, Tuyển tập báo cáo Hội nghị Khoa học cơ bản, Thành phố Hồ Chí Minh 12/2004. Lê Huy Minh, Nguyễn Chiến Thắng, Lưu Việt Hùng, 2005. Kết quả đo sâu từ telua tuyến Chợ Gạo- Hóc Môn, Tuyển tập báo cáo Hội nghị Khoa học kỹ thuật Địa vật lý Việt Nam lần thứ 4, 149-161. Lê Huy Minh, Phạm Văn Ngọc, D. Boyer, Nguyễn Ngọc Thủy, Lê Trường Thanh, Ngô Văn Quân, G. Marquis, 2009. Nghiên cứu chi tiết cấu trúc đứt gãy Lai Châu - Điện Biên bằng phương pháp đo sâu từ tellur, Tạp chí Địa chất loạt A, 311, 11 -21. W. R. Peltier and J. F. Hermance, 1971. Magnetotelluric Fields of a Gaussian Electrojet, Canadian Journal of Earth Sciences, 8(3), 338-346. V. N. Pham, D. Boyer, T. K. T. Nguyen, and V. G. Nguyen, 1994. Deep ground-water investigation by combined VES/MTS methods near Ho Chi Minh City, Viet Nam, Ground water, 32, 4, 675-682. P. Tapponier et al., 1990. The Ailao Shan/Red River metamorphic belt: Tertiary left-lateral shear between Indochina and South China, Nature, 343, 431-437. Nguyễn Ngọc Thu, 2004. Xử lý tổng hợp tài liệu địa vật lý vùng thành phố Hồ Chí Minh, Luận án Tiến sĩ vật lý, Đại học Quốc Gia Tp. Hồ Chí Minh, 146tr. Cao Đình Triều, 2005. Trường địa vật lý và cấu trúc thạch quyển lãnh thổ Việt Nam. Nxb. KHKT, Hà Nội, 330tr. Cao Đình Triều, Phạm Huy Long, Đỗ Văn Lĩnh, Lê Văn Dũng, Cao Đình Trọng, 2013. Địa động lực hiện đại lãnh thổ Việt Nam. Nxb. Khoa học Tự nhiên và Công nghệ, 242tr.J. T. Weaver and A. K. Agarwal, 1993. Automatic 1-D inversion of magnetotelluric data by the method of modeling, Geophys. J. Int, 112, 115-123. This  paper  presents the magnetotelluric  sounding  results  of  Cu  Chi  -  Ben  Cat  profile  acrossing  the  Saigon  River fault. Results obtained by one-dimensional inversion of the data of a typical station located near the middle of the profile show that the geoelectric structure of the study area consists of three layers, in which the resistivities of the superficial and the underlying layers are relatively low compared with that of the intermediate layer. This geoelectric structure is then used to estimate the influence of the equatorial electrojet on the magnetotelluric measurements carried out in the region. Magnetotelluric forward problems were calculated and compared for cases of the present and the absent of the equatorial electrojet model. Results show that in the range of periods less than 0.7s, the apparent resistivity measured are not affected by the equatorial electrojet. Therefore, the apparent resistivity data measured in the period range less than 0.7s of all stations on the profile have been used for two-dimensional inversion to obtain geoelectric cross-section acrossing the Saigon River fault. The geoelectric cross-section down to a depth of 10km obtained by two-dimensional inversion shows a geoelectric structure consist of 3 layers: a low resistivity superficial layer, a resistive intermediate layer and a low resistivity underlying layer. The superficial layer is clearly related to the sedimentary series. The intermediate layer may relate to the intrusive and consolidated rocks. The underlying layer may reflect conductive materials causing by high temperature condition at depth. The interface between the intermediate and the underlying layers at around 3km depth corresponds probably to the crystalline basement. The low resistivity regions under the C4 and C2 stations may be related to the Duong Minh Chau - Dau Tieng - Can Gio and the Saigon River faults, correspondingly

    Medication Adherence in Cardiovascular Diseases

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    Cardiovascular disease is a significant cause of death globally. While effective long-term medications that reduce the risk of morbidity and mortality related to cardiovascular disease are readily available, nonadherence to prescribed medications remains a significant reason for suboptimal management. Consequently, this might lead to increased morbidity and mortality and healthcare costs. Medication nonadherence causes are myriad and complicated, with factors at the patient, healthcare provider, and health system levels. Many clinical trials have investigated interventions to target these factors for improving medication adherence, including improving patient education, testing behavioral interventions, implementing medication reminder tools, reducing medication costs, utilizing social support, utilizing healthcare team members, and simplifying medication dosing regimens. This book chapter describes factors influencing medication adherence and highlights the impact of varying levels of adherence on patients’ clinical and economic outcomes. We also summarize interventions for improving medication adherence in cardiovascular disease

    Clinical and Virological Study of Dengue Cases and the Members of Their Households: The Multinational DENFRAME Project

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    Dengue is the most important mosquito-borne viral disease in humans. This disease is now endemic in more than 100 countries and threatens more than 2.5 billion people living in tropical countries. It currently affects about 50 to 100 million people each year. It causes a wide range of symptoms, from an inapparent to mild dengue fever, to severe forms, including dengue hemorrhagic fever. Currently no specific vaccine or antiviral drugs are available. We carried out a prospective clinical study in South-East Asia and Latin America, of virologically confirmed dengue-infected patients attending the hospital, and members of their households. Among 215 febrile dengue subjects, 177 agreed to household investigation. Based on our data, we estimated the proportion of dengue-infected household members to be about 45%. At the time of the home visit, almost three quarters of (29/39) presented an inapparent dengue infection. The proportion of inapparent dengue infection was higher in South-East Asia than in Latin America. These findings confirm the complexity of dengue disease in humans and the need to strengthen multidisciplinary research efforts to improve our understanding of virus transmission and host responses to dengue virus in various human populations

    Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

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    Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

    The global response: How cities and provinces around the globe tackled Covid-19 outbreaks in 2021

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    Background: Tackling the spread of COVID-19 remains a crucial part of ending the pandemic. Its highly contagious nature and constant evolution coupled with a relative lack of immunity make the virus difficult to control. For this, various strategies have been proposed and adopted including limiting contact, social isolation, vaccination, contact tracing, etc. However, given the heterogeneity in the enforcement of these strategies and constant fluctuations in the strictness levels of these strategies, it becomes challenging to assess the true impact of these strategies in controlling the spread of COVID-19.Methods: In the present study, we evaluated various transmission control measures that were imposed in 10 global urban cities and provinces in 2021 Bangkok, Gauteng, Ho Chi Minh City, Jakarta, London, Manila City, New Delhi, New York City, Singapore, and Tokyo.Findings: Based on our analysis, we herein propose the population-level Swiss cheese model for the failures and pit-falls in various strategies that each of these cities and provinces had. Furthermore, whilst all the evaluated cities and provinces took a different personalized approach to managing the pandemic, what remained common was dynamic enforcement and monitoring of breaches of each barrier of protection. The measures taken to reinforce the barriers were adjusted continuously based on the evolving epidemiological situation.Interpretation: How an individual city or province handled the pandemic profoundly affected and determined how the entire country handled the pandemic since the chain of transmission needs to be broken at the very grassroot level to achieve nationwide control

    Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

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    Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

    On Structured Argumentation with Conditional Preferences

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    We study defeasible knowledge bases with conditional preferences (DKB). A DKB consists of a set of undisputed facts and a rule-based system that contains different types of rules: strict, defeasible, and preference. A major challenge in defining the semantics of DKB lies in determining how conditional preferences interact with the attack relations represented by rebuts and undercuts, between arguments. We introduce the notions of preference attack relations as sets of attacks between preference arguments and the rebuts or undercuts among arguments as well as of preference attack relation assignments which map knowledge bases to preference attack relations. We present five rational properties (referred to as regular properties), the inconsistency-resolving, effective rebuts, context-independence, attack monotonicity and link-orientation properties generalizing the properties of the same names for the case of unconditional preferences. Preference attack relation assignment are defined as regular if they satisfy all regular properties. We show that the set of regular assignments forms a complete lower semilattice whose least element is referred to as the canonical preference attack relation assignment. Canonical attack relation assignment represents the semantics of preferences in defeasible knowledge bases as intuitively, it could be viewed as being uniquely identified by the regular properties together with the principle of minimal removal of undesired attacks. We also present the normal preference attack relation assignment as an approximation of the canonical attack relation assignment

    Establishment automatically contour blasting passport for tunnel in AutoCAD by VOLVN 3.0 software

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    The smooth blasting method has been researched, developed and strongly applied for long-term underground construction, such as principal mining excavations, tunnels and hydroelectric projects... with the main purpose of minimizing the explosion impact on rock and creating a well-shaped boundary. In this research, a software was developed to establish automatically the tunnel contour blasting passport in AutoCAD. Using the software in each blast design model, it is quickly possible to determine number of blastholes, specific charge, specific drilling and drawing automatically of blasting passport in AutoCAD. The interaction between the software and AutoCAD is a new and important factor that helps to complete an automatically closed cycle on computer from introducing parameters to designing blasting passport in AutoCAD, thereby contributing to increase efficiency of production and minimize risks in blasting works
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