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Many natural forests in Southeast Asia are degraded following decades of logging. Restoration of these forests is delayed by ongoing logging and tropical cyclones, but the implications for recovery are largely uncertain. We analysed meteorological, satellite and forest inventory plot data to assess the effect of Typhoon Doksuri, a major tropical cyclone, on the forest landscapes of central Vietnam consisting of natural forests and plantations. We estimated the return period for a cyclone of this intensity to be 40 years. Plantations were almost twice as likely to suffer cyclone damage compared to natural forests. Logged natural forests (9–12 years after cessation of government-licensed logging) were surveyed before and after the storm with 2 years between measurements and remained a small biomass carbon sink (0.1 ± 0.3 Mg C ha −1 yr −1 ) over this period. The cyclone reduced the carbon sink of recovering natural forests by an average of 0.85 Mg C ha −1 yr −1 , less than the carbon loss due to ongoing unlicensed logging. Restoration of forest landscapes in Southeast Asia requires a reduction in unlicensed logging and prevention of further conversion of degraded natural forests to plantations, particularly in landscapes prone to tropical cyclones where natural forests provide a resilient carbon sink. This article is part of the theme issue ‘Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration’.

Changes in ambient temperature have been reported as an important risk factor for respiratory diseases among pre-school children. However, there have been few studies so far on the effects of temperature on children respiratory health in developing countries including Vietnam. This study examined the impact of short-term changes in ambient temperature on hospital admissions for acute lower respiratory infection (ALRI) among children aged less than 5 years old in Ho Chi Minh City (HCMC), Vietnam. Data on daily hospital admissions from 2013 to 2017 were collected from two large paediatric hospitals of the city. Daily meteorological data of the same period were also collected. Time series analysis was performed to evaluate the association between risk of hospitalisations and temperatures categorised by seasons, age, and causes. We found that a 1 °C increase in maximum temperature was associated with 4.2 and 3.4% increase in hospital admission for ALRI among children 3–5 years old during the dry season and the rainy season, respectively. Surprisingly, in the rainy season, a rise of 1°C diurnal temperature range (DTR) was significantly associated with a decrease from 2.0 to 2.5% risk of hospitalisation for ALRI among children

ObjectivesThis study quantified the secondhand smoke (SHS) concentration in a sample of public places in Vietnam to determine changes in SHS levels 5 years after a public smoking ban was implemented.MethodsTwo monitoring campaigns, one in 2013 (before the tobacco control law was implemented) and another in 2018 (5 years after the implementation of the law) were conducted in around 30 restaurants, cafeterias and coffee shops in major cities of Vietnam. Concentrations of PM2.5, as an indicator of SHS, were measured by portable particulate matter monitors (TSI SidePak AM510 and Air Visual Pro).ResultsThe geometric mean PM2.5 concentration of all monitored venues was 87.7 µg/m3 (83.7–91.9) in the first campaign and 55.2 µg/m3 (53.7–56.7) in the second campaign. Pairwise comparison showed the PM2.5 concentrations in the smoking observed area was triple and double those in the non-smoking area and the outdoor environment. After adjusting for sampling locations and times, the SHS concentration 5 years after the implementation of the tobacco control law reduced roughly 45%.ConclusionThe study results indicate an improvement in air quality in public places in Vietnam via both the reduction in PM2.5 levels and the number of people observed smoking. However, greater enforcement of the free-smoke legislation is needed to eliminate SHS in public places in Vietnam.

Under the trade international integration, vertical price transmission in agri-food export supply chains is an essential issue that needs attention. This study analyses the price transmission from export prices to farm-gate prices of the black-tiger shrimp and white-leg shrimp production in Vietnam. Monthly price series of black-tiger shrimp and white-leg shrimp were collected from January 2015 to October 2020, from the Department of Aquaculture of Ca Mau, Soc Trang, Kien Giang, Ben Tre provinces; Vietnam Association of Seafood Exporters and Producers, and Vietnam market analysis and forecast joint stock company. The Johansen cointegration test, the Toda-Yamamoto Granger causality test, the Engle-Granger’s two-stage estimation, and the asymmetric error correction model using the Houck and Ward approach were applied. The results showed a long-term relationship between the farm-gate prices and export prices for both black-tiger shrimp and white-leg shrimp. The export prices were the price leader. In the long run, the price transmission from export prices to farm-gate prices in both black-tiger shrimp and white-leg shrimp was incomplete; however, the white-leg shrimp’s price transmission was noticeably better than black-tiger shrimp’s. In the short run, there was no statistically significant effect of export prices on farm-gate prices of black-tiger shrimp; while the price transmission of white-leg shrimp was significant but relatively slow rate. The price transmission for black-tiger shrimp and white-leg shrimp was symmetric in the short run and the long run. The findings of this study are useful for farmers in developing production and business strategy. Symmetric price transmission in both the short run and the long run is a positive signal for farmers to invest in sustainable production approaches and to meet stringent standard requirements of the export market.

Combined effects of global warming and rapid urbanization replace green spaces with urban facilities. Children in urban areas are at a higher risk of heat-related adverse health effects. Our study aimed to examine the protective effect of urban green space on heat-related respiratory hospitalization among children under 5 years of age in Hanoi, the capital city of Vietnam. We estimated district-specific meteorological conditions from 2010 to 2014 by using a dynamic downscaling approach with a fine-resolution numerical climate model. The green space in each district was calculated using satellite data. The attributable fraction of heat-related respiratory hospitalization was estimated using a two-stage model, including a distributed lag non-linear model (DLNM) coupled with multivariate meta-analysis. The association between heat-related respiratory hospitalization and green spaces at the district level was explored using a linear regression model. The central districts were more crowded and hotter, with less green spaces than the outer districts. At temperatures 34 °C (extreme heat threshold), the hospitalizations in the central districts increased significantly; however, in the outer districts, the hospitalization rate was insignificant. On average, extreme heat attributed 0.33% to citywide hospitalization, 0.35% in the center, and 0.32% in the outer region. Every 1% increase in the green space fraction will reduce heat-related respiratory hospitalization risk by 3.8%. Heat significantly increased the risk of respiratory hospitalization among children under 5 years in Hanoi, Vietnam. These findings are valuable for authorities to consider strategies to protect children's health against the effects of heat, including increasing green space.

International audience; The Mekong delta is inhabited by more than 20 million people in Vietnam and is highly vulnerable to the additive effects of land subsidence and sea-level rise due to global climate change. To cover Delta-wide from 2015-2020, there are 250 multi-temporal SAR Sentinel-1 images, where each scene is stored in complex values with about 14 GB memory data. To do interferometry processing, we need to be able to intelligently handle ensemble 250x14 GB data. Thus, although Sentinel-1 Big Data offers the best opportunity for land subsidence monitoring, it is challenge due to an unprecedented big volume of multi-temporal InSAR dataset. In this paper, the objective is to provide a discuss on a feasible method to handle the Delta-wide land subsidence by TOPS interferometry.

IntroductionGenome-wide association studies (GWAS) have successfully revealed genetic risk variants for schizophrenia (SCZ). However, the vast majority of GWAS largely comprise European samples. As a result, the derived polygenic risk scores (PRS) show decreased predictive power when applied to non-European populations.ObjectivesA long-term scientific cooperation between the Charité Universitätsmedizin Berlin and the Hanoi Medical University aims to address this limitation by recruiting a large genetic cohort of comprehensively phenotyped schizophrenia patients and controls in Vietnam.MethodsA pilot study was conducted at the Department of Psychiatry of the Medical University Hanoi in 2017. Data collection encompassed i) genome-wide SNP genotyping of 200 schizophrenia patients and 200 control subjects ii) structured interviews to assess symptom severity (PANSS), iii) clinical parameters (e.g. duration of illness, medication) and demography.ResultsSCZ-PRS of the pilot sample (N=400) were generated using different training data sets: i) European, ii) East-Asian and iii) mixed GWAS summary statistics from the Psychiatric Genomics Consortium’s latest discovery sample. Most variance explained was observed using a mixed discovery sample (R2liability=0.053, p=3.11*10-8, Pd 2liability=0.0503, p=6.78*10-8, Pd 2liability=0.0363, p = 4.26*10-6, Pd ConclusionsWith this pilot project we established an efficient recruitment, genotyping and data analysis pipeline. Our results corroborate previous findings indicating that transferability of PRS across populations depends on the ancestral composition of the initial discovery dataset. We therefore aim to expand data collection efforts in the future in order to improve risk prediction across diverse populations.DisclosureNo significant relationships.

The paper is devoted to numerical study of the influence of the initial shape of a vapor bubble on the surface impact of the water jet emerging due to the bubble collapse. This problem is relevant to spreading of high-temperature melt under a layer of subcooled water. The vapor bubbles formed on the melt-water interface, upon complete penetration in water, are condensing rapidly to produce high-velocity water micro-jets directed towards the melt. Impact of these jets causes upward melt splashing. Superposition of these processes forms a dynamic layer where melt is mixed with water; the presence of this premixed layer can be a pre-requisite for steam explosion. In this work, numerical modelling by the boundary element method is performed for the collapse of a bubble of an oblate spheroid. It is shown that the water jets generated in this process possess the impulse comparable to that generated by a collapsing spherical vapour bubble of the same volume. By the numerical simulations and subsequent estimates it is obtained that collapse of non-spherical bubbles near the melt-water interface produces melt splashes of the height of few centimetres, which is sufficient for the occurrence of steam explosions.

Collapse of a hot vapour bubble captured by subcooled water can produce a cumulative jet similar to that appearing in cavitating flows. In the context of stratified steam explosions following spreading of hot melt under a water layer, impact of the water jets can be a reason for melt splashes promoting the mixing of cold and hot liquids necessary for energetic interaction. In this work, the characteristics of the directional water flow caused by collapse of a bubble near a wall are obtained, and a correlation is given which relates the ultimate height of melt rise to the bubble parameters and droplet size. Estimates relevant to melt splashes caused by the cumulative water jet impact are presented which agree with the experimental observations available in the literature.

Collapse of superheated vapor bubbles in subcooled water is studied from the viewpoint of possible mechanisms of premixed zone formation in stratified vapor explosions. Numerical modeling is performed for spherically symmetric bubble collapse in subcooled water, with different initial vapor superheats. The kinetic energy of liquid flow generated due to vapor collapse is obtained. It is shown that the primary mechanism triggering vapor collapse and water flow is vapor cooling in the bubble by colder interface, lowering the vapor pressure and generating necessary pressure drop. Results are compared with an idealized case of bubble vapor maintained at the saturation conditions corresponding to water temperature. Two-dimensional simulations of bubble collapse near solid wall are performed by the boundary element method. Implications to stratified vapor explosions are discussed, and correlations for possible splashing of melt due to the impact of water jets generated by a collapsing steam bubble are obtained.

Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs), thereby ultimately affecting olfactory-driven behaviours. We describe the molecular effects of 10 insect repellents and a pyrethroid insecticide with known repellent activity on two highly specific Aedes aegypti (Diptera: Culicidae) ORs, AaOR2 + AaOR7 and AaOR8 + AaOR7, exquisitely sensitive to key mosquito attractants indole and (R)-(-)-1-octen-3-ol, expressed in oocytes of Xenopus (Anura: Pipidae). Our study demonstrates that insect repellents can both inhibit odorant-evoked currents mediated by ORs and independently elicit currents in the absence of odorants. All of the repellents had effects on one or both ORs; most of these compounds were selective inhibitors and showed a high degree of specificity in their capacity to activate the two ORs. These results show that a range of insect repellents belonging to structurally diverse chemical classes modulate the function of mosquito ORs through multiple molecular mechanisms.

A total of 300 children aged five years and under, referred for routine EEG investigations, were included in this study. It was possible to obtain recordings during natural sleep in 250 of the 300 children, using stick-on electrodes. Of the 250 with natural-sleep recordings, 110 children had normal records both awake and asleep. In 73 cases the awake record was normal but the asleep record showed abnormalities, the most common being spike discharges (60 children). Of these 60 children, 52 had a history suggestive of epilepsy or of febrile convulsions. A further 27 children had recordings which were equally abnormal awake and asleep, and 37 showed abnormalities while awake but greater abnormalities while asleep. It is concluded that useful additional information can be obtained from the EEG if young children are encouraged to sleep naturally during the recording, and that this can be done without sedation, even in a busy, routine EEG department.

This paper presents a miniature timing microsystem based on a pair of wafer-level packaged co-integrated low and high frequency silicon resonators −430kHz and 26MHz respectively- so as to implement a μW-level accurate, low power, temperature-compensated real time clock (RTC) and to generate low noise, low jitter clocks at any frequency between 1–50MHz in a reconfigurable way at less than 10mW power dissipation. Singulated resonator dies were assembled on a CMOS wafer by thermo-compressive bonding on Au stud-bumps and the resulting system was characterized at wafer level.

This paper presents a miniature timing microsystem based on a pair of co-integrated low and high frequency silicon resonators -430kHz or 522kHz and 26MHz respectively-so as to implement a μW-level accurate, low power, temperature-compensated real time clock (RTC) and to generate low noise, low jitter clocks at any frequency between 1-50MHz in a reconfigurable way at less than 10mW power dissipation.

The angular correlation function (ACF) of scattering amplitudes is presented using the second-order Kirchhoff approximation (KA) with angular and propagation shadowing functions. The theory is applicable to surfaces with large radii of curvature and high slopes of the order of unity. The correlation consists of contributions from single and second-order scattering. The single scattering provides the necessary condition for substantial correlation to occur. The second-order scattering yields high peaks in the correlation function. The ladder term gives a peak when two waves that have the same incident and scattering angles are traveling in the same direction. The cyclic term gives another peak in the time-reversed direction. These two peaks are related by the reciprocity condition. Although the second-order KA contains several approximations and the solution is simplified to yield a numerically tractable form, its agreement with experimental results is excellent. The theory correctly shows the peaks in the ACF observed in both co-polarization and cross-polarization responses. The width of the memory line is also very close to the value predicted by the theory.

153 asthmatic children from 5 to 36 months (mean age: 26 months) were investigated. The aim of the study was twofold: 1) to determine the reliability and limits of an allergologic diagnosis before 36 months of age; 2) to compare the predictive value of skin-tests with other allergologic tests. Results were expressed according to a score involving 5 parameters derived from the allergologic investigation. Each parameter represented one point: atopic past history, increased level of total IgE antibodies related to the age, presence of blood specific IgE antibodies, blood hypereosinophilia. Infants were considered allergic if their score level was greater than or equal to 3. Concordance between this score level and each parameter was as follows: Positive skin-test 83%; Blood hypereosinophilia 82%; Presence of specific IgE antibodies 80%; Increased level of total IgE 78%; Familial history of atopy 54%. It is concluded that, in allergic infants, a significative link exists between positive skin-test plus the presence of specific IgE antibodies and an atopic disease. However, more children have to be enrolled in a multivariant analysis to assess definitively the predictive value to this score.