Energy Conservation Analysis of Human Body Locomotion Modelled as an Inverted Quadruple Pendulum Dynamical System

Human body parts move when they are involved in an activity. In this paper an attempt is made to analyse the motion of the parts in line with the conservation of energy principle. Human body was modelled longitudinally as an inverted Quadruple pendulum. Analytical approach was adopted in analysing the potential and kinetic energies of the systems segments. The findings are consistent with the ones in the literature. Specifically, there is a positive correlation between the height of segments of the system and mechanical energy at the different segments of the system

Isometric thermogenesis at rest and during movement: a neglected variable in energy expenditure and obesity predisposition

Isometric thermogenesis as applied to human energy expenditure refers to heat production resulting from increased muscle tension. While most physical activities consist of both dynamic and static (isometric) muscle actions, the isometric component is very often essential for the optimal performance of dynamic work given its role in coordinating posture during standing, walking and most physical activities of everyday life. Over the past 75 years, there has been sporadic interest into the relevance of isometric work to thermoregulatory thermogenesis and to adaptive thermogenesis pertaining to body-weight regulation. This has been in relation to (i) a role for skeletal muscle minor tremor or microvibration – nowadays referred to as ‘resting muscle mechanical activity’ – in maintaining body temperature in response to mild cooling; (ii) a role for slowed skeletal muscle isometric contraction–relaxation cycle as a mechanism for energy conservation in response to caloric restriction and weight loss and (iii) a role for spontaneous physical activity (which is contributed importantly by isometric work for posture maintenance and fidgeting behaviours) in adaptive thermogenesis pertaining to weight regulation. This paper reviews the evidence underlying these proposed roles for isometric work in adaptive thermogenesis and highlights the contention that variability in this neglected component of energy expenditure could contribute to human predisposition to obesity

Relationship of human intrusion on avian body mass: Do recreationists hinder birds’ abilities to acquire fat during migration?

Many North American landbirds undergo biannual migration, which is energetically costly. Quality stopover sites are crucial to avian survival, as they provide opportunities to quickly replenish fat stores, rest, and avoid predation. One component of habitat quality that is often overlooked is the level of pedestrian activity, which birds interpret as potential predators. If intrusion levels are high, birds will flush readily and may not adequately restore energy reserves, which hinders successful migration. I compared body mass index between birds at different intrusion levels, testing the hypothesis that birds near continuous intrusion are less capable of replenishing body fat. Results between migratory guilds indicate long-distance migrants require areas of low intrusion to sufficiently acquire fat stores. In contrast, resident species are able to replenish body mass despite human intrusion. Since Neotropical migrants show increased sensitivity to human presence, conservation measures should focus on reducing pedestrian activity for quality stopover habitats

Integrated Spatial Analysis for Human-Wildlife Coexistence in the American West

The future of conservation and human–wildlife relationships in the American West is at a defining moment. The region consists of a mosaic of land-cover types, with large amounts of public land under varying degrees of protection, use, and ownership. This public land provides the foundation for high levels of connectivity and habitat for healthy populations of wildlife, including those with large resource requirements such as large and wide-ranging mammals (Barnes et al 2016). However, space for wildlife is under threat in the West. Energy development projects, urban and ex-urban sprawl, increasing road traffic and density, and amenity-driven human migration are dramatically changing the ecological landscape (Leu et al 2008). The social landscape is rapidly changing as well, with new residents bringing different worldviews, economic activities, and expectations regarding wildlife and their habitats (Teel and Manfredo 2010). Because maintaining and establishing landscape connectivity for wildlife in part depends on facilitating their movement across privately-owned lands that connect protected areas, balancing disparate human priorities with wildlife conservation across large landscapes in the American West requires novel approaches to conservation practice. Inclusion of multi-level drivers of social processes and human behavior in spatial analysis and conservation planning represents a tremendous opportunity to improve outcomes for both wildlife and humans in shared landscapes (Lischka et al 2018). A growing body of work has demonstrated novel ways to spatially integrate social and ecological factors that can better inform decision making for human–wildlife coexistence under changing conditions (Bryan et al 2011, Behr et al 2017, Williamson et al 2018). Here, we build on that foundation to underscore the utility of integrating social factors into traditional spatial analysis to promote human–wildlife coexistence in the American West

ATLAS: A Traffic Load Aware Sensor MAC Design for Collaborative Body Area Sensor Networks

In collaborative body sensor networks, namely wireless body area networks (WBANs), each of the physical sensor applications is used to collaboratively monitor the health status of the human body. The applications of WBANs comprise diverse and dynamic traffic loads such as very low-rate periodic monitoring (i.e., observation) data and high-rate traffic including event-triggered bursts. Therefore, in designing a medium access control (MAC) protocol for WBANs, energy conservation should be the primary concern during low-traffic periods, whereas a balance between satisfying high-throughput demand and efficient energy usage is necessary during high-traffic times. In this paper, we design a traffic load-aware innovative MAC solution for WBANs, called ATLAS. The design exploits the superframe structure of the IEEE 802.15.4 standard, and it adaptively uses the contention access period (CAP), contention free period (CFP) and inactive period (IP) of the superframe based on estimated traffic load, by applying a dynamic “wh” (whenever which is required) approach. Unlike earlier work, the proposed MAC design includes load estimation for network load-status awareness and a multi-hop communication pattern in order to prevent energy loss associated with long range transmission. Finally, ATLAS is evaluated through extensive simulations in ns-2 and the results demonstrate the effectiveness of the protocol

Mean Radiant Cooling in a Hot-Humid Climate

Shaded interior mass walls in a hot-humid climate can be thermally grounded to an earth heat sink under an insulated structure. The mean radiant temperature (MRT) of the shaded and thermally grounded interior mass walls will be cooler in summer than normal light weight frame wall construction and significantly below human body temperature. Because the interior walls are cool, the human body will lose heat by radiation to the cooler interior mass walls. The result is an improvement in the bio-climatic sensation of comfort and an increase in energy conservation

From growth to extinction : explored by life history and metabolic theory

The laws of energy and material conservation are fundamental principles across various scales and systems. Based on the conservation laws, I derive several theoretical models to understand mechanisms behind the energy budget of ontogenetic growth and the pattern of the late Pleistocene extinction of megafauna in the Americas. First, I present a model, empirically grounded in data from birds and mammals, that correctly predicts how growing animals allocate food energy between synthesis of new biomass and maintenance of existing biomass. Previous energy budget models have typically been based on rates of either food consumption or metabolic energy expenditure. The model provides a framework that reconciles these two approaches and highlights the fundamental principles that determine rates of food assimilation and rates of energy allocation to maintenance, biosynthesis, activity, and storage. The model predicts that growth and assimilation rates for all animals should cluster closely around two canonical curves. Second, the previous model, which focuses on endotherms, has been extended to understand effects of temperature on the energy budget of ontogenetic growth of ectotherms. A tendency for ectotherms to develop faster but mature at smaller body sizes in warmer environments has been studied for decades, and is called the temperature size rule (TSR). It can be explained by a simple model in which the rate of growth or biomass accumulation and the rate of development or differentiation have different temperature dependence. The model accounts for both TSR and the less frequently observed reverse-TSR, predicts the fraction of energy allocated to maintenance and synthesis over the course of development, and the temperature independent growth efficiency. It also predicts that less total energy is expended when developing at warmer temperatures for TSR and vice versa for reverse-TSR. It has important implications for effects of climate change on ectothermic animals and also provides how selection may lead to the evolution of both TSR and reverse-TSR. Finally, based on mammalian life history and life history scaling relationships, an exploitation-extinction theory has been developed for the rate of human harvest in the disappearance of the Pleistocene megafauna in the Americas. The theory demonstrates that the added mortality of human harvest on populations need not be selective to produce a size-biased extinction. The variation in the adult natural instantaneous mortality rate and/or the maximum recruitment compensation at any body mass are main components determining the probability of extinction. The theory successfully predicts the shapes of the extinction probability curves for the late Pleistocene extinction in the Americas. It provides a theoretical basis to challenge a major criticism of the overkill theory that early Paleoindian hunters had to be extremely selective to have produced the highly size-biased pattern characteristic to the late Pleistocene extinction of megafauna in the Americas