Simulation of the impacts of constructed wetlands on river flow using WSIMOD

Increased demands for land use in urban development have reduced the extent of open water bodies in recent decades, leading to more frequent extreme flows in urban rivers. Urban nature-based solutions, such as constructed wetlands, have the potential to provide significant water management benefits if implemented on a large scale, well-maintained, and used sustainably. However, their actual benefits in urban water systems have not been adequately evaluated, and the underlying mechanisms remain underexplored. These limitations hinder the effective planning of the integration methods for constructed wetlands. To assess the water management benefits of constructed wetlands at the catchment scale, this study analyses river flow data collected before and after wetland construction in Enfield, London. The Water Systems Integrated Modelling (WSIMOD) framework is used to simulate the integrated catchment water cycle, and the constructed wetlands module is conceptualised and included in the WSIMOD to evaluate their interactions within the urban catchment water cycle. Scenarios are designed to assess the impacts of varying configurations and sizes of the wetlands on the river flow. The findings indicate that constructed wetlands are observed to attenuate river flow peaks and increase low flows. Constructed wetlands reduce the frequency of river flow peaks at the catchment scale; results show that in the case of Enfield, converting 1% of the catchment area to wetlands can decrease high flows (10% exceedance probability) by 18–23% and increase low flows (90% exceedance probability) by 35–50%, reducing the flashiness of the urban water cycle. Incorporating wetlands arranged in parallel exhibits superior performance in attenuating flow peaks compared to wetlands arranged in series, as the wetlands placed in parallel can provide more space to store rapidly generated runoff. The results quantified the effects of constructed wetlands on high and low flows in the urban water system, using the WSIMOD to provide recommendations on wetland connection modes for decision-making

Time encoding via unlimited sampling: theory, algorithms and hardware validation

An alternative to conventional uniform sampling is that of time encoding, which converts continuous-time signals into streams of trigger times. This gives rise to Event-Driven Sampling (EDS) models. The data-driven nature of EDS acquisition is advantageous in terms of power consumption and time resolution and is inspired by the information representation in biological nervous systems. If an analog signal is outside a predefined dynamic range, then EDS generates a low density of trigger times, which in turn leads to recovery distortion due to aliasing. In this paper, inspired by the Unlimited Sensing Framework (USF), we propose a new EDS architecture that incorporates a modulo nonlinearity prior to acquisition that we refer to as the modulo EDS or MEDS. In MEDS, the modulo nonlinearity folds high dynamic range inputs into low dynamic range amplitudes, thus avoiding recovery distortion. In particular, we consider the asynchronous sigma-delta modulator (ASDM), previously used for low power analog-to-digital conversion. This novel MEDS based acquisition is enabled by a recent generalization of the modulo nonlinearity called modulo-hysteresis. We design a mathematically guaranteed recovery algorithm for bandlimited inputs based on a sampling rate criterion and provide reconstruction error bounds. We go beyond numerical experiments and also provide a first hardware validation of our approach, thus bridging the gap between theory and practice, while corroborating the conceptual underpinnings of our work

Marangoni-driven patterns, ridges and hills in surfactant-covered parametric surface waves

Parametric oscillations of an interface separating two fluid phases create nonlinear surface waves, called Faraday waves, which organise into simple patterns, such as squares and hexagons, as well as complex structures, such as double hexagonal and superlattice patterns. In this work, we study the influence of surfactant-induced Marangoni stresses on the formation and transition of Faraday-wave patterns. We use a control parameter, B, that assesses the relative importance of Marangoni stresses as compared with the surface-wave dynamics. Our results show that the threshold acceleration required to destabilise a surfactant-covered interface through vibration increases with increasing B. For a surfactant-free interface, a square-wave pattern is observed. As B is incremented, we report transitions from squares to asymmetric squares, weakly wavy stripes and ultimately to ridges and hills. These hills are a consequence of the bidirectional Marangoni stresses at the neck of the ridges. The mechanisms underlying the pattern transitions and the formation of exotic ridges and hills are discussed

Prediction of seismic demands for ancillary elements in vertically irregular steel frames

This paper investigates the elastic and inelastic seismic response of non-structural ancillary components within multi-storey steel frames exhibiting typical vertical irregularities. For this purpose, a large set of 188 steel moment framed structures, characterised by various combinations of setbacks within their elevations, is considered. The frames, which are designed according to European code provisions, are described in detail in terms of their configurations, member sizes, and dynamic characteristics. Within these structures, non-structural components, characterised by various periods and strength reduction factors are mounted at individual floors and assessed in terms of both their displacement and acceleration response under seismic loading. Detailed nonlinear dynamic time-history analyses are carried out using a suite of 100 ground motion records from both far-field and near-field sources, selected from the PEER NGA database in accordance with FEMA-695 requirements, scaled at intensity levels consistent with both elastic and inelastic conditions. The results are used to assess the suitability of existing models which are primarily developed to predict the seismic response of non-structural components in regular frames. The results reveal, with 95 % confidence, that frame irregularities have a direct and significant effect on the seismic response of non-structural components, and therefore, various modifications to current models are necessary to capture adequately the influence of vertical frame irregularities. Based on the findings, unified analytical models are proposed and shown to predict, well within an accuracy of 10 %, the seismic displacement and acceleration response of non-structural components mounted within the floors of both regular and irregular multi-storey steel frames

The effect of HLA polymorphism on immune response to SARS‐CoV‐2 vaccination within an infection‐naïve, vulnerable population with end‐stage renal disease

HLA genes exhibit a high degree of polymorphism, contributing to genetic variability known to influence immune responses to infection. Here we investigate associations between HLA polymorphism and serological and T-lymphocyte responses to the BNT162b2 and ChAdOx1 SARS-CoV-2 vaccines within a population receiving maintenance haemodialysis (HD) for End-Stage Renal Disease (ESRD). Our primary objective was to identify HLA alleles associated with diminished serological and T-cellular responsiveness to vaccination. As a secondary objective, the associations between HLA type and COVID-19 disease outcomes were investigated using an independent ESRD cohort (n = 327). This aimed to determine if the alleles associated with poor vaccine response were also linked to unfavourable infection outcomes. In the main study, serum from 225 SARS-CoV-2 infection-naïve patients was HLA-typed using high-resolution Next Generation Sequencing, and serological titres were analysed for the presence of SARS-CoV-2 spike glycoprotein-specific antibodies after two doses of vaccination. A subset of patients (n = 33) was also tested for a T-lymphocyte response. Overall, 89% (n = 200) of patients seroconverted, but only 18% (n = 6) of the cellular response subgroup had a positive T-lymphocyte response. The HLA class II alleles DPB1*104:01, DRB1*04:03 and DRB1*14:04 and HLA class I alleles B*08:01 and B*18:01 were found to significantly correlate with seronegativity, and DQB1*06:01 correlated with serological responsiveness. We were unable to analyse the effect of HLA on disease outcome and T-lymphocyte response due to sample size limitations. Our results suggest pathways for further research and begin to elucidate the relationship between HLA polymorphism and immune responses in the vulnerable ESRD population

Magnetic field effects on the corrosion behavior of magnetocaloric alloys LaFe13.9Si1.4Hy under ferromagnetic states

La(Fe,Si)13-based alloys, with giant magnetocaloric effect, still encounter significant degradation issues prior to commercial viability. In this work, the corrosion behavior of ferromagnetic La(Fe,Si)13Hy was investigated with electrochemical linear polarization resistance measurements under conditions with zero, 1 T parallel, and perpendicular magnetic fields, mimicking practical application scenarios. The results demonstrated that both parallel and perpendicular magnetic fields had a suppressive effect on corrosion rates due to the combined influence of magnetohydrodynamic forces and magnetic field gradient forces. The inhibiting efficiency of the parallel field decreased with increasing exposure period, while that of the perpendicular field continued to increase over time. The magnetic field also affected the relative proportion of rust phases, and thereby the protectiveness of the rust layer. This highlights the importance of conducting experiments under service conditions to understand the degradation mechanisms of magnetic cooling devices

Global, regional, and national burden of suicide, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background Deaths from suicide are a tragic yet preventable cause of mortality. Quantifying the burden of suicide to understand its geographical distribution, temporal trends, and variation by age and sex is an essential step in suicide prevention. We aimed to present a comprehensive set of global, regional, and national estimates of suicide burden. Methods We produced estimates of the number of deaths and age-standardised mortality rates of suicide globally, regionally, and for 204 countries and territories from 1990 to 2021, and disaggregated these results by age and sex. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 estimates of deaths attributable to suicide were broken down into two comprehensive categories: those by firearms and those by other specified means. For this analysis, we also produced estimates of mean age at the time of death from suicide, incidence of suicide attempts compared with deaths, and age-standardised rates of suicide by firearm. We acquired data from vital registration, verbal autopsy, and mortality surveillance that included 23 782 study-location-years of data from GBD 2021. Point estimates were calculated from the average of 1000 randomly selected possible values of deaths from suicide by age, sex, and geographical location. 95% uncertainty intervals (UIs) were derived from the 2·5th and 97·5th percentiles from a 1000-draw distribution. Findings Globally, 746 000 deaths (95% UI 692 000–800 000) from suicide occurred in 2021, including 519 000 deaths (485 000–556 000) among males and 227 000 (200 000–255 000) among females. The age-standardised mortality rate has declined over time, from 14·9 deaths (12·8–15·7) per 100 000 population in 1990 to 9·0 (8·3–9·6) per 100 000 in 2021. Regionally, mortality rates due to suicide were highest in eastern Europe (19·2 [17·5–20·8] per 100 000), southern sub-Saharan Africa (16·1 [14·0–18·3] per 100 000), and central sub-Saharan Africa (14·4 [11·0–19·1] per 100 000). The mean age at which individuals died from suicide progressively increased during the study period. For males, the mean age at death by suicide in 1990 was 43·0 years (38·0–45·8), increasing to 47·0 years (43·5–50·6) in 2021. For females, it was 41·9 years (30·9–46·7) in 1990 and 46·9 years (41·2–52·8) in 2021. The incidence of suicide attempts requiring medical care was consistently higher at the regional level for females than for males. The number of deaths by suicide using firearms was higher for males than for females, and substantially varied by country and region. The countries with the highest age-standardised rate of suicides attributable to firearms in 2021 were the USA, Uruguay, and Venezuela. Interpretation Deaths from suicide remain variable by age and sex and across geographical locations, although population mortality rates have continued to improve globally since the 1990s. This study presents, for the first time in GBD, a quantification of the mean age at the time of suicide death, alongside comprehensive estimates of the burden of suicide throughout the world. These analyses will help guide future approaches to reduce suicide mortality that consider a public health framework for prevention