Associations of the COVID-19 pandemic with older individuals’ healthcare utilization and self-reported health status: a longitudinal analysis from Singapore

Background The COVID–19 pandemic has challenged the capacity of healthcare systems around the world and can potentially compromise healthcare utilization and health outcomes among non-COVID–19 patients. Objectives To examine the associations of the COVID-19 pandemic with healthcare utilization, out-of-pocket medical costs, and perceived health among middle-aged and older individuals in Singapore. Method Utilizing data collected from a monthly panel survey, a difference-in-differences approach was used to characterize monthly changes of healthcare use and spending and estimate the probability of being diagnosed with a chronic condition and self-reported health status before and during the COVID-19 outbreak in 2020. Subjects Data were analyzed from 7569 nationally representative individuals from 2019 January and 2020 December. Measures Healthcare utilization and healthcare spending by medical service categories as well as self-reported health status. Results Between January and April 2020 (the first peak period of COVID-19 in Singapore), doctor visits decreased by 30%, and out-of-pocket medical spending decreased by 23%, mostly driven by reductions in inpatient and outpatient care. As a result, the probability of any diagnosis of chronic conditions decreased by 19% in April 2020. The decreased healthcare utilization and spending recovered after lifting the national lockdown in June, 2020 and remained similar to the pre-pandemic level through the rest of 2020. Conclusions Middle-aged and older Singaporeans’ healthcare utilization and the diagnosis of chronic conditions substantially decreased during the first peak period of the COVID-19 outbreak. Further studies to track the longer-term health effect of the pandemic among non-COVID-19 patients are warranted.

“There Are Stereotypes for Everything”: Multiracial Adolescents Navigating Racial Identity under White Supremacy

Despite the enduring popular view that the rise in the multiracial population heralds our nation’s transformation into a post-racial society, Critical Multiracial Theory (MultiCrit) asserts that how multiracial identity status is constructed is inextricably tied to systems and ideologies that maintain the white supremacist status quo in the United States. MultiCrit, like much of the multiracial identity literature, focuses predominantly on the experiences of emerging adults; this means we know little about the experiences of multiracial adolescents, a peak period for identity development. The current paper uses MultiCrit to examine how a diverse sample of multiracial youth (n = 49; Mage = 15.5 years) negotiate racial identity development under white supremacy. Our qualitative interview analysis reveals: (a) the salience of socializing messages from others, (b) that such messages reinforce a (mono)racist societal structure via discrimination, stereotyping, and invalidation, and (c) that multiracial youth frequently resist (mono)racist assertions as they make sense of their own identities. Our results suggest that multiracial youth are attentive to the myriad ways that white supremacy constructs and constrains their identities, and thus underscores the need to bring a critical lens to the study of multiracial identity development.

Price Discounts and Consumer Load-Shifting Behavior in the Smart Grid

This paper studies the impact of consumers' individual attitudes towards load shifting in electricity consumption in an electricity market that includes a single electricity provider and multiple consumers. A Stackelberg game model is formulated in which the provider uses price discounts over a finite number of periods in order to induce incentives for consumers to shift their peak period loads to off-peak periods. The equilibrium outcomes are investigated and the analytical results are derived for this type of market, where not only the response behaviors of independent consumers are diverse but also an individual consumer's valuation of electricity consumption varies across periods. The obtained results demonstrate that consumer sensitivities to price discounts significantly impact price discounts and load-shifts, which are not necessarily monotonic. The authors also observe that a diverse market leads to lower peak-to-average values and provider payoffs compared to a homogenous market unless the latter one is composed of consumers with relatively lower inconvenience costs during the peak periods.

Modelling Ocean Waves and an Investigation of Ocean Wave Spectra for the Wave-to-Wire Model of Energy Harvesting

Ocean wave energy is an abundant and clean source of energy; however, its potential is largely untapped. Although the concept of energy harvesting from ocean waves is antiquated, the advances in wave energy conversion technologies are embryonic. In many major studies related to wave-to-wire technologies, ocean waves are considered to be regular waves with a fixed amplitude and frequency. However, the actual ocean waves are the sum of multiple frequencies that exhibit a particular sea state with a significant wave height and peak period. Therefore, in this paper, detailed modelling of the ocean waves is presented and different wave spectra are analyzed. The wave spectra will eventually be used for the generation of wave elevation time series. Those time series can be used for the wave-to-wire model-based studies for improved investigations into wave energy conversion mechanisms, mimicking the real ocean conditions.

Demand Based Cost Optimization of Electric Bills for Household Users

Abstract- Internet of Things (IoT) is increasingly becoming the vehicle to automate, optimize and enhance the performance of systems in the energy, environment, and health sectors. In this paper, we use Wi-Fi wrapped sensors to provide online and in realtime the current energy consumptions at a device level, in a manner to allow for automatic control of peak energy consumption at a household, factory level, and eventually at a region level, where a region can be defined as an area supported by a distinct energy source. This allows to decrease the bill by avoiding heavily and controllable loads during high tariff slice and/or peak period per household and to optimize the energy production and distribution in a given region. The proposed model relies on adaptive learning techniques to help adjust the current load, while taking into consideration the actual and real need of the consumer. The experiments used in this study makes use of current and voltage sensors, Arduino platform, and simulation system. The main performance indexes used are the control of a peak consumption level, and the minimum time needed to adjust the distribution of load in the system. The system was able to keep the maximum load at a maximum of 10 kW in less than 10 seconds of response time. The level and response time are controllable parameters.

Assessment of Operational Performance for an Integrated ‘Power to Synthetic Natural Gas’ System

This article presents a power to SNG (synthetic natural gas) system that converts hydrogen into SNG via a methanation process. In our analysis, detailed models for all the elements of the system are built. We assume a direct connection between a wind farm and a hydrogen generator. For the purposes of our calculations, we also assume that the hydrogen generator is powered by the renewable source over a nine-hour period per day (between 21:00 and 06:00), and this corresponds to the off-peak period in energy demand. In addition, a hydrogen tank was introduced to maximize the operating time of the methanation reactor. The cooperation between the main components of the system were simulated using Matlab software. The primary aim of this paper is to assess the influence of various parameters on the operation of the proposed system, and to optimize its yearly operation via a consideration of the most important constraints. The analyses also examine different nominal power values of renewables from 8 to 12 MW and hydrogen generators from 3 to 6 MW. Implementing the proposed configuration, taking into account the direct connection of the hydrogen generator and the methanation reactor, showed that it had a positive effect on the dynamics and the operating times of the individual subsystems within the tested configuration.

Study on the Resonant Behaviors of a Bottom-Hinged Oscillating Wave Surge Converter

This paper studied the resonant behaviors of a bottom-hinged oscillating wave surge converter (OWSC) as well as the relationship of resonance with the response and capture width ratio (CWR). The time-domain dynamic equation of an OWSC in shallow water based on the boundary element method (BEM) was solved by a Python code, considering the corrected wave surface and the nonlinearities of restoring moment, drag, and friction. The unknown factors, such as wave surface corrected factor and drag coefficient, were effectively calibrated with computational fluid dynamics (CFD) method. An intermediate initial angle in free decay is appropriate for use to determine the natural period. Under regular waves, the resonance occurs near the natural period for the uniform wave amplitude, rather than the uniform wave torque amplitude, and can disappear due to the amplification of Power Take-Off (PTO) friction. Under unit-amplitude regular waves, the period of maximum CWR is relatively close to the period of maximum velocity, but far from the resonant period. Under irregular waves, no stable resonance is observed because the maximum equivalent pitch angle appears at different peak periods of wave spectra with the variation in PTO damping. When the period of a regular wave or the peak period of an irregular wave is close to the natural period, a phase hysteresis of velocity relative to wave torque always occurs.

The Dynamics of Cross-Sector Collaboration in Centralized Disaster Governance: A Network Study of Interorganizational Collaborations during the MERS Epidemic in South Korea

The debate continues as to which governance structure is most appropriate for collaborative disaster response, particularly between centralization and decentralization. This article aims to contribute to this debate by analyzing the structural characteristics of a multisectoral network that emerged and evolved under strong state control during the 2015 outbreak of Middle East respiratory syndrome-coronavirus (MERS) in South Korea. This study particularly focuses on the evolution of intra- and inter-sectoral collaboration ties in the network. The data for the study were collected through a content analysis of government documents and news articles. Using social network analysis, the authors found that the network evolved into a centralized structure around a small number of governmental organizations at the central level, organizing the ties between participating organizations rather hierarchically. The network displayed a preponderance of internal ties both among health and non-health organizations and among public and nonpublic health organizations, but under different influences of structural characteristics. This tendency was intensified during the peak period. Based on these findings, the authors conclude that the centralization of disaster management may not or only marginally be conducive to cross-sector collaboration during public health disasters, calling for a careful design of governance structures for disaster response.

Comparative evaluation of rapid isothermal amplification and antigen assays for screening testing of SARS-CoV-2

Human transmission of SARS-CoV-2 and emergent variants of concern has continued to occur globally, despite mass vaccination campaigns. Public health strategies to reduce virus spread should therefore rely, in part, on frequent screening with rapid, inexpensive, and sensitive tests. We evaluated two digitally integrated rapid tests and assessed their performance using stored nasal swab specimens collected from individuals with or without COVID-19. An isothermal amplification assay combined with a lateral flow test had a limit of detection of 10 RNA copies per reaction, and a positive percent agreement (PPA)/negative percent agreement (NPA) during the asymptomatic and symptomatic phases of 100%/100% and 95.83/100%, respectively. Comparatively, an antigen-based lateral flow test, had a limit of detection of 30,000 copies, and a PPA/NPA during the asymptomatic and symptomatic phases of 82.86%/98.68% and 91.67/100%, respectively. Both the isothermal amplification and antigen-based lateral flow tests had optimized detection of SARS-CoV-2 during the peak period of transmission; however, the antigen-based test had reduced sensitivity in clinical samples with qPCR Ct values greater than 29.8. Low-cost, high-throughput screening enabled by isothermal amplification or antigen-based techniques have value for outbreak control.

Efficacy of Herbal Medicine Administration using Neem (Azadirchta indica L) Leaves as Case Study

Plants used for treatment of diverse ailments primitively are concocted and used indiscriminately. The efficacy of "Herbal medicine" which is an ancient tradition, used in some parts of Nigeria was investigated to establish herbal applications of Neem (Azadirachta indica) leaves. Neem leaves (Azadirachta indica) was popularly recognised for the treatment of malaria fever. The leaves were plucked at appropriate peak period of the day when oil and moisture contents were recorded maximum. The peak period of contents was found to occurred between 8am-10am on a very sunny days, 10am to 12 on cool days, and 3:00pm to 5:00pm on cloudy days. Aqueous extract from macerated Neem leaves was subjected to qualitative and quantitative analysis. Available phytochemicals evaluated include; saponin (34.89mg/g), tannin (31.715mg/g), flavonoid (31.835mg/g), phenol (43.59mg/g), terpernoid (14.585mg/g), cardiac glycosides (39.335mg/g), steroid (16.185mg/g) and alkaloid (28.76mg/g). These values differ significantly to recommended oral dosage formulation for human consumption: Saponin (1.433ml), Tannin (1.418ml), Flavonoid (13.91ml), Phenol (2.29ml), Terpernoid (8.23ml), Cardiac Glycosides (0.003177ml), Steroid (0.62mg/g). Consequently, local consumption of herbal resources should be regulated to avoid abuse and long or short-term effects of drug contents as proven in the neem leaves as local herbs.