Studies show that mental health promotion is an effective strategy that can reduce the burden of mental health disorders and improve overall well-being in both children and adults. In addition to promoting high levels of mental well-being and preventing the onset of mental illness, these mental health promotion programmes, including mental illness prevention interventions, help increase levels of mental health literacy in community members. While there is evidence showing the effectiveness of mental health promotion, much of what is known about this field is informed by studies conducted in high-income countries. There is a need to gather evidence about the effectiveness of such interventions in low- and middle-income countries (LMICs) where mental health services are often inadequate. In this systematic review, we synthesised the available published primary evidence from sub-Saharan Africa (SSA) on the types and effectiveness of mental health promotion programmes for young people. We performed a search of selected global databases (PubMed, PsycINFO, ScienceDirect and Google Scholar) and regional databases (Sabinet African Journals). We included observational, mixed methods, trials, pilots and quantitative original papers published from 2013 to 2023. We used the Mixed Methods Appraisal Tool (MMAT) to evaluate the quality of methods in selected studies, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA-2020) for reporting the evidence gathered. We identified 15 types of youth mental health promotion and illness prevention interventions. Among those identified, we found that school-based interventions enhanced mental health literacy, mental health-seeking behaviours and self-assurance and confidence among young people. Family-based interventions also showed a potential to improve relationships between young people and their caregivers. Future studies should explore how to further strengthen school- and family-based interventions that promote mental health among young people.

Comprehensive coherent structures around a surface-mounted low aspect ratio square cylinder in uniform flow with an oblique angle of $45^{\circ }$ were investigated for cylinder-width-based Reynolds numbers of 3000 and 10 000 by direct numerical simulation based on a topology-confined mesh refinement framework. High-resolution simulations and the critical-point concept were scrutinized to reveal for the first time the reasonable and compatible topologies of flow separation and complete near-wall structures, due to their extensive impact on various engineering applications. Large-scale horseshoe vortices are observed at two notable foci in the viscous sublayer. Within this layer, a wall-parallel jet is formed by downflow intruding into the bottom surface at the half-saddle point, then deflecting in the upstream direction and finally penetrating the bottom surface until the half-saddle point. A pair of conical vortices on the cylinder's top surface switch themselves on two sides of the square cylinder, where the switching frequency is identical with that of the sway of the side shear layer. The undulation of the Kelvin–Helmholtz instability is identified in the instantaneous development of a conical vortex and side shear layer, where the scaling of the ratio of the Kelvin–Helmholtz and von Kármán frequencies follows the power-law relation obtained by Lander et al. (J. Fluid Mech., vol. 849, 2018, pp. 1096–1119). Large-scale arch-shaped vortex is often detected in the intermediate wake region of a square cylinder, involving two interconnected portions, such as the leg portion separated from leeward surfaces and head portion rolled up from the top surface. The leg portion of the arch-shaped vortex was rooted by two foci near the bottom-surface plane.

This research studies the robustness of permanence and the continuous dependence of the stationary distribution on the parameters for a stochastic predator–prey model with Beddington–DeAngelis functional response. We show that if the model is extinct (resp. permanent) for a parameter, it is still extinct (resp. permanent) in a neighbourhood of this parameter. In the case of extinction, the Lyapunov exponent of predator quantity is negative and the prey quantity converges almost to the saturated situation, where the predator is absent at an exponential rate. Under the condition of permanence, the unique stationary distribution converges weakly to the degenerate measure concentrated at the unique limit cycle or at the globally asymptotic equilibrium when the diffusion term tends to 0.

The introduction of the 2012 Labour Code is considered ‘groundbreaking’ in industrial relations in Vietnam. However, knowledge about the effects of this law is still minimal. This study provides the first evidence of the impacts of the law on worker outcomes, disaggregated by location and migration status. The Vietnam Labour Force Survey is used as the primary dataset. Both difference-in-differences and fixed-effect models are applied in the investigation. The estimated results show a relationship between the introduction of the law and the labour supply of contracted workers in urban areas, especially long-term migrant workers. Furthermore, income for these long-term migrant contract workers was affected significantly by the introduction of the law. A link between the law and health insurance participation was also found among non-migrant contracted workers in urban areas. We also perform estimations using a short panel sample and find notable results. The study likewise reveals disadvantages of rural workers compared to urban workers in terms of earnings, and of short-term migrants compared to other workers, in terms of labour supply.

Vietnam’s initial response to Covid-19 was conspicuous for various reasons, including how its attempt at securitisation drew deeply from historical narratives, symbols, and traditions specific to the Vietnamese experience, as well as how the securitisation project was not simply top-down and state-driven but also featured ground-up participation where the public was mobilised to participate in and actively reiterate securitisation practices. This richly textured empirical case study of the workings of Vietnamese society and politics represents an invitation to explore key debates surrounding securitisation theory. Reflecting on the empirical material of the case, this paper builds on scholarship seeking to highlight the shortcomings of the Copenhagen School’s model of securitisation and from there further explore securitisation theory and its limits. It takes aim at how the audience and its agency is conceptualised in the theory and develops the notions of ‘historical resources’ and ‘activation architecture’ to more adequately explain the processes of securitisation.

Leonetti and Luca [‘On the iterates of the shifted Euler’s function’, Bull. Aust. Math. Soc., to appear] have shown that the integer sequence $(x_n)_{n\geq 1}$ defined by $x_{n+2}=\phi (x_{n+1})+\phi (x_{n})+k$, where $x_1,x_2\geq 1$, $k\geq 0$ and $2 \mid k$, is bounded by $4^{X^{3^{k+1}}}$, where $X=(3x_1+5x_2+7k)/2$. We improve this result by showing that the sequence $(x_n)$ is bounded by $2^{2X^2+X-3}$, where $X=x_1+x_2+2k$.

Objectives: Healthcare-associated infections (HAIs) are one of the greatest challenges and concerns in Vietnam and around the world. Many studies have shown that HAIs may result in an increase in hospital length of stay, antibiotic use, multidrug-resistant organism (MDROs) infections, treatment costs, and mortality. Therefore, in the past 5 years, the Department of Infection Control of Cho Ray Hospital has carried out many infection and prevention control (IPC) activities to reduce the rates of HAI and MDRO infection. We evaluated IPC activities and results achieved in these efforts at Cho Ray Hospital during 2017–2021. Methods: We described the implemented IPC activities and retrospectively collected data from HAIs surveillance reports during 2017–2021 for 3 intensive care units (ICUs): ICU-B, ICU-D, and the NICU. Results: In the past 5 years, we implemented synchronous IPC activities, including promoting hand hygiene training and surveillance, environmental cleaning surveillance, carrying out improvement projects such as a ventilator-associated pneumonia (VAP) prevention bundle, an MDRO prevention bundle, and an environmental cleaning quality improvement project. Many positive results were achieved, although a slight increase in the HAI incidence occurred in 2021 due to the COVID-19 pandemic. Overall, the hand hygiene compliance rate increased from 49.7% to 83.8%. The rate of HAIs per 1,000 patient days decreased steadily from 5.4 to 2.4. The VAP rate fell from 30.5 to 17.2 per 1,000 patient days, and the central-line–associated bloodstream infection (CLABSI) rate decreased gradually from 5.4 to 2.4 per 1,000 patient days. The catheter-associated urinary tract infection (CAUTI) rate decreased from 2.9 to 0.9 per 1,000 patient days, and the MDRO infection rate decreased significantly from 32.7 to 11.3 per 1,000 patient days. Conclusions: The synchronous implementation of HAI prevention bundles promoting hand hygiene and environmental cleaning achieved significant effects in the efforts to decrease HAIs and MDROs in the ICUs of Cho Ray Hospital.

Objectives: In Vietnam, the burden of healthcare-associated infections (HAIs), especially by multidrug-resistant organisms (MDROs), can be greater at national hospitals where a high number of severe patients from lower-tier hospitals are received for treatment. To reduce MDRO and HAI incidences at the tropical diseases intensive care unit (ICU) of Cho Ray Hospital, the final line of treatment for 20 southern provinces of Vietnam, a comprehensive infection prevention bundle was developed and implemented in 2019. In this retrospective study, we evaluated the effectiveness of this intervention in preventing MDRO infections and HAIs among patients at risk. Methods: The infection prevention bundle included elements to improve administration controls, environmental controls, and personal protective equipment usage. The bundle was implemented via training and active monitoring. Medical data, such as microbiology results, length of hospital stay, treatment cost of all patients admitted to the targeted ICU, and data on adherence to the bundle elements, were collected via routine monitoring from July to December 2019. These data were reviewed and analyzed. An independent 2-sample t test was used to calculate the significance of the differences in MDRO and HAI rates before and after the intervention. Results: The mean number of MDRO infections decreased significantly after implementation of the infection prevention bundle (7.0 vs 3.3; P = .011). HAI and ventilator-associated pneumonia (VAP) rates also decreased significantly (5.9 vs 3.7; P= .013 and 20.4 vs 13.7; P=0.047, respectively). The mean total treatment cost per patient was reduced by 1.8 million VND (US $76.76). Bundle-element adherence was high throughout the intervention period, ranging from 72.7% (putting MDRO sign on beds) to 100% (hand hygiene, cohort patients, environment cleaning). Conclusions: Implementation of an appropriate infection prevention bundle with a high adherence rate by healthcare workers helped to effectively reduce MDRO infection and HAI rates in the tropical diseases ICU.

Objectives: Studies have revealed that a relatively high incidence of severe infection and mortality in COVID-19 patients is attributed to healthcare-associated infections (HAIs). We implemented a study in 2 field hospitals dedicated to COVID-19 treatment in Da Nang, Vietnam (July–August 2020), and Ho Chi Minh City, Vietnam (August–October 2021), to identify pathogens, risk factors, and outcomes associated with HAIs. Methods: We applied a prospective study tool to estimate HAI incidence among 1,454 patients. HAIs are diagnosed and ascertained using surveillance criteria established by the US Centers for Disease Control and Prevention. All patients hospitalized for COVID-19 for at least 2 days were enrolled in this assessment of HAI risks, pathogens, and outcomes. Results: Among 1,454 sampled patients, 391 patients had 423 HAIs (27.1%). The highest proportion occurred in ICUs, with 422 HAI patients (34.1%). Pneumonia (n = 331, 78.3%) and bloodstream infections (n = 55, 13.1%) were the most common HAIs. Multidrug-resistant (MDR) bacteria, such as Klebsiella pneumonia (27.9%) and Acinetobacter baumannii (25.3%), were the most commonly isolated organisms. Ventilators and central venous catheters were independently associated with HAIs. Regarding the mortality rates, 55% of deaths occurred in intensive care units. Patients with HAIs (70.3%) were twice as likely to die compared to patients without HAIs (38.8%). HAIs leading to septic shock caused almost triple mortality (n = 58, 90.6%) compared with non-HAI patients (n = 412, 38.8%). HAIs prolonged hospital stay: 24.7 days for patients with HAIs and 19.1 days for patients without HAIs (P < .001). Conclusions: Patients with COVID-19–related critical illnesses are at high risk of HAIs from multidrug-resistant (MDR) bacteria. HAIs prolong hospitalization, whereas HAIs with septic shock almost tripled mortality. Guidelines and procedures to prevent and control HAIs caused by MDR bacteria as well as training and monitoring on aseptic-compliant techniques during invasive clinical procedures are needed.

We report on the modification of the spectrum of a passive scalar inside a turbulent flow by the injection of large bubbles. Although the spectral modification through bubbles is well known and well analysed for the velocity fluctuations, little is known on how bubbles change the fluctuations of an approximately passive scalar, in our case temperature. Here we uncover the thermal spectral scaling behaviour of a turbulent multiphase thermal mixing layer. The development of a $-3$ spectral scaling is triggered. By injecting large bubbles (${Re}_{{bub}} = {O}(10^2)$) with gas volume fractions $\alpha$ up to 5 %. For these bubbly flows, the $-5/3$ scaling is still observed at intermediate frequencies for low $\alpha$ but becomes less pronounced when $\alpha$ further increases and it is followed by a steeper $-3$ slope for larger frequencies. This $-3$ scaling range extends with increasing gas volume fraction. The $-3$ scaling exponent coincides with the typical energy spectral scaling for the velocity fluctuations in high-Reynolds-number bubbly flows. We identify the frequency scale of the transition from the $-5/3$ scaling to the $-3$ scaling and show how it depends on the gas volume fraction.