Probabilistic procedure for wood-frame roof sheathing panel debris impact to windows in hurricanes

The assessment of losses during extreme events such as hurricanes is important for performance-based design of residential buildings. In this paper, a methodology for estimating the probability of debris impact, specifically roof sheathing panels, to windows as a result of hurricanes is introduced and applied to a series of illustrative examples. The methodology is a combination of approaches on flat plate trajectories, numerical hurricane modeling, and statistical analysis of structural capacity. Within this methodology, one can estimate the probability of impact for one or more windows in a certain house group as a hurricane approaches and passes on a deterministic track as defined by the center of its eye. The impact probability is analyzed for each hour making up the full hurricane duration rather than a single analysis using the blended (total) hurricane statistics. An illustration of the method is presented through an assessment of windborne debris impacts to windows in a house group located near the US Gulf coast using a hurricane having the same track as hurricane Katrina in 2005. As a result, the probability of each window being hit by a roof sheathing panel (RSP) during each hour of the hurricane as well as during each of the example hurricanes is presented. The results quantify the probability from hour to hour during a hurricane and will provide a more accurate estimate of the probability and timing of pressurization of buildings for total loss estimation including rainwater intrusion volumes

Risk analysis procedure for woodframe roof sheathing panel debris impact to windows in hurricanes

The assessment of losses during extreme events such as hurricanes is important for performance-based design of residential buildings. In this paper, a methodology for estimating the risk of debris impact, specifically roof sheathing panels, to windows as a result of hurricanes is introduced and applied to an illustrative example. The method is a combination of approaches on flat plate trajectories, numerical hurricane modeling, and statistical analysis of structural capacity. Within this methodology, one can estimate the risk of impact for one or more windows in a certain house group as a hurricane approaches and passes on a deterministic track as defined by the center of its eye. The impact risk is analyzed for the each hour making up the full hurricane duration rather than a single analysis using the blended (total) hurricane statistics. An illustration of the method is presented through a risk assessment of windborne debris impacts to windows in a house group located near the U.S. Gulf coast using a hurricane having the same track as hurricane Katrina in 2005. As a result, the probability of each window being hit by a roof sheathing panel (RSP) during each hour of the hurricane as well as during each hurricane is presented. The results quantify the risk from hour to hour during a hurricane and may serve to better orient houses in planned communities in hurricane prone regions as well as provide a better understanding of the interaction of hurricanes and structures.KEYWORDS: fragility, wind force, windborne debris, light-frame wood, hurrican

A hidden HIV epidemic among women in Vietnam

<p>Abstract</p> <p>Background</p> <p>The HIV epidemic in Vietnam is still concentrated among high risk populations, including IDU and FSW. The response of the government has focused on the recognized high risk populations, mainly young male drug users. This concentration on one high risk population may leave other populations under-protected or unprepared for the risk and the consequences of HIV infection. In particular, attention to women's risks of exposure and needs for care may not receive sufficient attention as long as the perception persists that the epidemic is predominantly among young males. Without more knowledge of the epidemic among women, policy makers and planners cannot ensure that programs will also serve women's needs.</p> <p>Methods</p> <p>More than 300 documents appearing in the period 1990 to 2005 were gathered and reviewed to build an understanding of HIV infection and related risk behaviors among women and of the changes over time that may suggest needed policy changes.</p> <p>Results</p> <p>It appears that the risk of HIV transmission among women in Vietnam has been underestimated; the reported data may represent as little as 16% of the real number. Although modeling predicted that there would be 98,500 cases of HIV-infected women in 2005, only 15,633 were accounted for in reports from the health system. That could mean that in 2005, up to 83,000 women infected with HIV have not been detected by the health care system, for a number of possible reasons. For both detection and prevention, these women can be divided into sub-groups with different risk characteristics. They can be infected by sharing needles and syringes with IDU partners, or by having unsafe sex with clients, husbands or lovers. However, most new infections among women can be traced to sexual relations with young male injecting drug users engaged in extramarital sex. Each of these groups may need different interventions to increase the detection rate and thus ensure that the women receive the care they need.</p> <p>Conclusion</p> <p>Women in Vietnam are increasingly at risk of HIV transmission but that risk is under-reported and under-recognized. The reasons are that women are not getting tested, are not aware of risks, do not protect themselves and are not being protected by men. Based on this information, policy-makers and planners can develop better prevention and care programs that not only address women's needs but also reduce further spread of the infection among the general population.</p

Current State of Stroke Care in Vietnam

Stroke is the leading cause of death and disability in Vietnam. This review aims to assess the current status of the stroke care system and quality criteria in the acute phase at stroke hospitals. In 2016, the Ministry of Health in Vietnam issued Circular 47, a mandate to build stroke units in Vietnam. The ANGELS program, which is supporting the World Stroke Organization to gain its goals, was implemented in 18 stroke‐ready hospitals in Vietnam to help address quality of stroke patient care in 2017. From the results achieved, we will continue to improve policies, strive to reach stroke benchmark goals, as well as plan to implement solutions in the future to build a better stroke system of care infrastructure in Vietnam

Threshold level of Peptest in diagnosing gastroesophageal reflux disease with extraesophageal symptoms: Evidence from Vietnam

Abstract Background and Aim We aimed to evaluate the application of Peptest, a novel technique to detect pepsin in the saliva, and identify its threshold level for the diagnosis of gastroesophageal reflux disease (GERD) with extraesophageal symptoms. Methods A cross‐sectional study was conducted in two groups: patients with extraesophageal GERD symptoms (symptomatic group divided into GERD and non‐GERD groups according to 24‐h esophageal pH‐impedance monitoring [pH‐I] results) and healthy controls. For the symptomatic group, endoscopy, pH 24 h, high‐resolution manometry (HRM), and salivary Peptest were performed. For the healthy control group, only Peptest was done. The accuracy of Peptest was compared with that of pH‐I by the Lyon consensus criteria. Results Chronic laryngitis was the most frequent extraesophageal symptom. On saliva testing, the GERD group had a higher prevalence of positive samples and pepsin concentration than the control group. Between GERD and non‐GERD groups, the optimal threshold level was 31.2 ng/mL, with a sensitivity of 86.7% and specificity of 27.5%. The optimal threshold level was 31.4 ng/mL to differentiate GERD from healthy controls, with a sensitivity of 86.7% and specificity of 66.0%. Age, number of total refluxes, DeMeester score, post‐reflux swallow‐induced peristaltic wave (PSPW) index, and mean nocturnal baseline impedence (MNBI) were associated with pepsin concentration. Regarding HRM metrics, there was no significant difference of pepsin concentration between low/normal upper esophageal sphincter (UES) resting pressure, low/normal lower esophageal sphincter (LES) resting pressure, low/normal 4‐s integrated relaxation pressure (IRP4s), and hypomotility/normal motility. Conclusion Patients with extraesophageal symptoms had a higher prevalence of positive Peptest. The optimum threshold level of 31.4 ng/mL had high sensitivity and moderate specificity to differentiate between patients with GERD and healthy controls

Automated assessment of tornado-induced building damage based on terrestrial laser scanning

Assessing the damage states of the built environment after a tornado is one method to better understand tornado induced loads and failure progress, as well as improve knowledge used for tornado mitigation, response, and recovery. Building damage states and geometry need to be measured and taken into consideration when estimating tornado wind pressures and speeds. This perishable damage data should be appropriately recorded, and investigations should be completed in a timely and unobtrusive manner in order to avoid interfering with clean up and recovery efforts that quickly change damage sites. Laser scanning or Light Detection And Ranging (LiDAR) provides 3D data that virtually captures damaged areas and allows for geometric queries and accurate measurements. Although robust, the 3D LiDAR data requires sophisticated data processing to extract meaningful information. The data processing becomes more challenging and time consuming when a large number of damaged buildings are investigated after a large-scale tornado. This research developed and tested a LiDAR data processing framework to automatically extract quantitative damage information needed for tornado wind speed estimation and structural damage analysis. The framework developed in this research includes methods for: 1) detecting damaged roof and wall surfaces in scans of damaged sites, 2) quantifying the percentages of roof/wall sheathing and covering losses, 3) estimating wind speeds at individual building scales, and 4) evaluating current tornado fragility models with actual damage information obtained by laser scanning. Performance of the developed methods was assessed with simulated data, laboratory scans, and actual data collected after large-scale tornadoes. A series of experiments in controlled conditions were conducted to determine the best algorithm settings and also objectively evaluate the performance of the proposed methods under varying environmental conditions. The proposed methods and their contributions to tornado wind speed estimation and structural fragility assessment were also tested with actual data collected after the Tuscaloosa, AL and Moore, OK tornadoes. The tests and case studies indicated that the detailed information extracted from LiDAR data could provide insight about tornado wind pressures and speeds with a resolution and accuracy not achievable with current visual inspections. This research determined the optimum data collection and processing settings that resulted in less than 10% error in calculating the percentages of roof and wall losses. The proposed method also estimates wind speeds at small-scale (individual buildings) as opposed to large-scale estimates often provided by field reconnaissance teams. Noting the fact that tornado wind speeds and pressures dramatically vary over short distances, the presented method provides engineers with a tool to improve the resolution and understanding of tornado effects, thereby improving building design and construction. (Published By University of Alabama Libraries

Association between in-hospital guideline adherence and postdischarge major adverse outcomes of patients with acute coronary syndrome in Vietnam: A prospective cohort study

OBJECTIVE: We aimed to determine the association between physician adherence to prescribing guideline-recommended medications during hospitalisation and 6-month major adverse outcomes of patients with acute coronary syndrome in Vietnam. DESIGN: Prospective cohort study. SETTING: The study was carried out in two public hospitals in Vietnam between January and October 2015. Patients were followed for 6 months after discharge. PARTICIPANTS: Patients who survived during hospitalisation with a discharge diagnosis of acute coronary syndrome and who were eligible for receiving at least one of the four guideline-recommended medications. EXPOSURES: Guideline adherence was defined as prescribing all guideline-recommended medications at both hospital admission and discharge for eligible patients. Medications were antiplatelet agents, beta-blockers, ACE inhibitors or angiotensin II receptor blockers and statins. MAIN OUTCOME MEASURE: Six-month major adverse outcomes were defined as all-cause mortality or hospital readmission due to cardiovascular causes occurring during 6 months after discharge. Cox regression models were used to estimate the association between guideline adherence and 6-month major adverse outcomes. RESULTS: Overall, 512 patients were included. Of those, there were 242 patients (47.3%) in the guideline adherence group and 270 patients (52.3%) in the non-adherence group. The rate of 6-month major adverse outcomes was 30.5%. A 29% reduction in major adverse outcomes at 6 months after discharge was found for patients of the guideline adherence group compared with the non-adherence group (adjusted HR, 0.71; 95% CI, 0.51 to 0.98; p=0.039). Covariates significantly associated with the major adverse outcomes were percutaneous coronary intervention, prior heart failure and renal insufficiency. CONCLUSIONS: In-hospital guideline adherence was associated with a significant decrease in major adverse outcomes up to 6 months after discharge. It supports the need for improving adherence to guidelines in hospital practice in low-income and middle-income countries like Vietnam