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Experts in data analytics and power engineering present techniques addressing the needs of modern power systems, covering theory and applications related to power system reliability, efficiency, and security. With topics spanning large-scale and distributed optimization, statistical learning, big data analytics, graph theory, and game theory, this is an essential resource for graduate students and researchers in academia and industry with backgrounds in power systems engineering, applied mathematics, and computer science.
Urban density is erroneously regarded as the main factor in the spread of COVID-19 in cities. A review of extant literature and findings from our case study of Karachi, Pakistan indicate that inequalities in income, healthcare, and living conditions play a key role in the spread of contagions along with government responsiveness to the pandemic. Moving forward, urban policies need to address these inequalities through changes in housing policies and decentralized governance systems. Cities must adapt to sustainable modes of travel, reduce digital inequalities, and encourage people friendly urban planning to become resilient in the face of pandemics.
COVID-19 has changed how urban residents relate to their cities. Urban centers have become epicenters of disease, which has raised questions about the long-term sustainability of high-density settlements and public transport usage. However, the spread of COVID-19 in cities is incorrectly attributed to urban density.
Using the case study of Karachi, Pakistan, we find that inequality of income, healthcare, and living conditions is a major contributing factor to the spread of COVID-19. Data on positive COVID-19 cases, density, and socioeconomic status were obtained at the Union Council level from administrative districts of Karachi, Pakistan between March 2020, and July 2020. Despite low population densities, low-to-middle income neighborhoods in Karachi had a higher proportion of positive cases. Further, the experience of dense cities such as Hanoi in Vietnam and New York in the US differs regarding the spread of COVID-19. Hence, the government's response to the pandemic is also a major factor in containing the outbreak.
Our findings suggest that a crisis in a city is exacerbated by its inability to take advantage of its density, inequality in the distribution of resources, lack of inclusiveness, and centralized governance mechanisms that make it difficult to respond quickly to situations. Thus, urban planning scholarship and practice should take an interdisciplinary approach to make cities equitable, inclusive, and adaptive.
Social media summary
Cities in the developing world have an opportunity for more resilient renewal in the post-COVID world.
Coronavirus disease 2019 (COVID-19) has rapidly spread globally, forcing countries to apply lockdowns and strict social distancing measures. The aim of this study was to assess eating habits and lifestyle behaviours among residents of the Middle East and North Africa (MENA) region during the lockdown. A cross-sectional study among adult residents of the MENA region was conducted using an online questionnaire designed on Google Forms during April 2020. A total of 2970 participants from eighteen countries participated in the present study. During the pandemic, over 30 % reported weight gain, 6·2 % consumed five or more meals per d compared with 2·2 % before the pandemic (P < 0·001) and 48·8 % did not consume fruits on a daily basis. Moreover, 39·1 % did not engage in physical activity, and over 35 % spent more than 5 h/d on screens. A significant association between the frequency of training during the pandemic and the reported change in weight was found (P < 0·001). A significantly higher percentage of participants reported physical and emotional exhaustion, irritability and tension either all the time or a large part of the time during the pandemic (P < 0·001). Although a high percentage of participants reported sleeping more hours per night during the pandemic, 63 % had sleep disturbances. The study highlights that the lockdown due to the COVID-19 pandemic caused a variety of lifestyle changes, physical inactivity and psychological problems among adults in the MENA region.
The design and experimental works of an autonomous robotic platform for road marks painting are presented in this paper as the first autonomous system of its kind. The whole system involves two main sub-systems, namely: an autonomous mobile robot navigation system which is used for recognizing the roads and estimating the position of road marks, and automatic road marks painting system that is attached to the mobile robot platform to control the spray of the paint on the road’s surface. The experimental results show the capability of the proposed system to perform the task of autonomous road marks painting with accuracy of ±10 cm.
Identifying developmental endophenotypes on the pathway between genetics and behavior is critical to uncovering the mechanisms underlying neurodevelopmental conditions. In this proof-of-principle study, we explored whether early disruptions in visual attention are a unique or shared candidate endophenotype of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). We calculated the duration of the longest look (i.e., peak look) to faces in an array-based eye-tracking task for 335 14-month-old infants with and without first-degree relatives with ASD and/or ADHD. We leveraged parent-report and genotype data available for a proportion of these infants to evaluate the relation of looking behavior to familial (n = 285) and genetic liability (using polygenic scores, n = 185) as well as ASD and ADHD-relevant temperament traits at 2 years of age (shyness and inhibitory control, respectively, n = 272) and ASD and ADHD clinical traits at 6 years of age (n = 94).
Results showed that longer peak looks at the face were associated with elevated polygenic scores for ADHD (β = 0.078, p = .023), but not ASD (β = 0.002, p = .944), and with elevated ADHD traits in mid-childhood (F(1,88) = 6.401, p = .013,
=0.068; ASD: F (1,88) = 3.218, p = .076), but not in toddlerhood (ps > 0.2). This pattern of results did not emerge when considering mean peak look duration across face and nonface stimuli. Thus, alterations in attention to faces during spontaneous visual exploration may be more consistent with a developmental endophenotype of ADHD than ASD. Our work shows that dissecting paths to neurodevelopmental conditions requires longitudinal data incorporating polygenic contribution, early neurocognitive function, and clinical phenotypic variation.
To explore influences on adolescent diet and physical activity, from the perspectives of adolescents and their caregivers, in Jimma, Ethiopia.
Qualitative design, using focus group discussions (FGD).
A low-income setting in Jimma, Ethiopia.
Five FGD with adolescents aged 10–12 years and 15–17 years (n 41) and three FGD with parents (n 22) were conducted.
Adolescents displayed a holistic understanding of health comprising physical, social and psychological well-being. Social and cultural factors were perceived to be the main drivers of adolescent diet and physical activity. All participants indicated that caregivers dictated adolescents’ diet, as families shared food from the same plate. Meals were primarily determined by caregivers, whose choices were driven by food affordability and accessibility. Older adolescents, particularly boys, had opportunities to make independent food choices outside of the home which were driven by taste and appearance, rather than nutritional value. Many felt that adolescent physical activity was heavily influenced by gender. Girls’ activities included domestic work and family responsibilities, whereas boys had more free time to participate in outdoor games. Girls’ safety was reported to be a concern to caregivers, who were fearful of permitting their daughters to share overcrowded outdoor spaces with strangers.
Adolescents and caregivers spoke a range of social, economic and cultural influences on adolescent diet and physical activity. Adolescents, parents and the wider community need to be involved in the development and delivery of effective interventions that will take into consideration these social, economic and cultural factors.
Continuous mode class-J radio-frequency (RF) power amplifier is a promising technique that extends the operating bandwidth of the conventional class-B power amplifier. However, the maximum theoretical efficiency is limited to that of the class-B power amplifier. In this paper, an enhanced mode of operation for the class-J power amplifier is proposed by incorporating a third harmonic voltage component to produce an optimum waveform for maximizing the fundamental voltage component and thereby to increase the drain efficiency and introduce a new design space. A detailed derivation for the necessary relations of output power, drain efficiency, and the required harmonic load impedances is provided, showing a significant improvement in theoretical maximum efficiency from 78.5 to 89.8%. In order to confirm the developed analytic approach, a 10 W prototype amplifier model was designed and fabricated to operate within the global system for mobile communications (GSM) frequency band 850–950 MHz using a commercial GaN power high electron mobility transistor (HEMT). The experimental results have indicated that the drain efficiency of the circuit varies from 68 to 80% within the desired band.