Behavioral inference of diving metabolic rate in free-ranging leatherback turtles

Good estimates of metabolic rate in free‐ranging animals are essential for understanding behavior, distribution, and abundance. For the critically endangered leatherback turtle (Dermochelys coriacea), one of the world’s largest reptiles, there has been a long‐standing debate over whether this species demonstrates any metabolic endothermy. In short, do leatherbacks have a purely ectothermic reptilian metabolic rate or one that is elevated as a result of regional endothermy? Recent measurements have provided the first estimates of field metabolic rate (FMR) in leatherback turtles using doubly labeled water; however, the technique is prohibitively expensive and logistically difficult and produces estimates that are highly variable across individuals in this species. We therefore examined dive duration and depth data collected for nine free‐swimming leatherback turtles over long periods (up to 431 d) to infer aerobic dive limits (ADLs) based on the asymptotic increase in maximum dive duration with depth. From this index of ADL and the known mass‐specific oxygen storage capacity (To2) of leatherbacks, we inferred diving metabolic rate (DMR) as . We predicted that if leatherbacks conform to the purely ectothermic reptilian model of oxygen consumption, these inferred estimates of DMR should fall between predicted and measured values of reptilian resting and field metabolic rates, as well as being substantially lower than the FMR predicted for an endotherm of equivalent mass. Indeed, our behaviorally derived DMR estimates ( mL O2 min−1 kg−1) were times the resting metabolic rate measured in unrestrained leatherbacks and times the average FMR for a reptile of equivalent mass. These DMRs were also nearly one order of magnitude lower than the FMR predicted for an endotherm of equivalent mass. Thus, our findings lend support to the notion that diving leatherback turtles are indeed ectothermic and do not demonstrate elevated metabolic rates that might be expected due to regional endothermy. Their capacity to have a warm body core even in cold water therefore seems to derive from their large size, heat exchangers, thermal inertia, and insulating fat layers and not from an elevated metabolic rate.

Gender profiles of behavioral attention in children with autism spectrum disorders

Objective: The attention profile of girls with autism spectrum disorder (ASD) is unclear compared with boys with ASD and typical children. This study aimed to investigate parent-reported ASD and ADHD symptoms in a large sample of boys and girls with and without ASD.

Method: A total of 124 normally intelligent children, half of them girls, 64 with autistic disorder or Asperger’s disorder, and 60 age- and gender-matched typically developing, aged 7 to 12 years, were recruited. Parents completed questionnaires regarding autistic and ADHD symptoms.

Results: No gender differences in social difficulties but more repetitive motor movements, communication difficulties, and inattention were reported in males, regardless of group. Younger boys with ASD had more elevated levels of hyperactivity-impulsivity than younger girls with ASD.

Conclusion: Gender differences in autistic symptoms and inattention in ASD reflected gender differences in typical children. More pronounced hyperactivity in younger boys with ASD could contribute to higher rates of clinical referral than girls.

Health, behavioral, cognitive, and social correlates of breakfast skipping among women living in socioeconomically disadvantaged neighborhoods

Breakfast skipping is a potentially modifiable behavior that has negative effects on health and is socioeconomically patterned. This study aimed to examine the intrapersonal (health, behavioral, and cognitive) and social factors associated with breakfast skipping. Nonpregnant women (n = 4123) aged 18-45 y from socioeconomically disadvantaged neighborhoods throughout Victoria, Australia, completed a postal questionnaire. Sociodemographic characteristics, diet, physical activity, sedentary behaviors, and cognitive and social factors were assessed by self-report. Breakfast skipping was defined in 2 ways: 1) "rarely/never" eating breakfast (n = 498) and 2) eating breakfast ≤2 d/wk (includes those who rarely/never ate breakfast; n = 865). Poisson regression was used to calculate prevalence ratios and linear trends, adjusting for covariates. The P values for linear trends are reported below. Compared with breakfast consumers, women who reported rarely/never eating breakfast tended to have poorer self-rated health (P-trend < 0.001), be current smokers (P-trend < 0.001), pay less attention to health (P-trend < 0.001), not prioritize their own healthy eating when busy looking after their family (P-trend < 0.001), have less nutrition knowledge (P-trend < 0.001), and a lower proportion were trying to control their weight (P-trend < 0.020). When breakfast skipping was defined as eating breakfast ≤2 d/wk, additional associations were found for having lower leisure-time physical activity (P-trend = 0.012) and less self-efficacy for eating a healthy diet (P-trend < 0.043). In conclusion, a range of intrapersonal and social factors were significantly associated with breakfast skipping among women living in socioeconomically disadvantaged areas. Acknowledging the cross-sectional design and need for causal confirmation, programs that aim to promote breakfast consumption in this population group should consider targeting family-related barriers to healthy eating and nutrition knowledge.

Decision-Making in Economics: Critical Lessons from Neurobiology

In this chapter, the authors consider some of the issues regarding the rational choice decision framework in neoclassical economics and how it can particularly be found wanting in the absence of due consideration for some of the underlying critical neurobiological factors which govern decision making. They develop a critical decision problem and explore the scenario where the solution predicted by formal economic theory may be in conflict with the decision that actually occurs. Such conflict is especially relevant in the context of economic decision making in emerging markets where there can be a lack of trust in the system by the agents operating within it. Based on logically consistent arguments derived from the extant literature, the authors argue that non-consideration of underlying neurobiological factors is a direct cause of this conflict.

Cost planning and control : case study of design economics for constructability and prefabrication construction

Cost management includes planning and control, and constructability1 and prefabrication construction are two main design economics factors for early cost planning decision. Despite the fact that constructability and prefabrication have been considered in design and cost planning, there is no guarantee if the intention meets the expectation. This requires on-going control during construction stage. In fact, prefabrication construction has been encouraged for some years, application is not always positive. One of the reasons is its constructability. This paper investigates the appropriate research methodology to determine how design for prefabrication and constructability will contribute to cost planning through control and review during construction stage. Through a study of an Australian residential project using prefabrication in structural concrete, internal partitioning and internal fit-out, this research concludes that case study is a viable choice. Prefabrication construction does provide a positive impact on the major project objectives: time, cost and quality. Cost reduction is due to saving in time related preliminaries as a direct result of time reduction of onsite activities whilst quality is ensured due to better control of prefabricated components inside the factories. However, it can only be achieved after considering constructability: suitable materials choice, design for available skills, use of available plant, and clear communication. The keys are through plan at design phase and control in construction stage.

Essays on the economics of natural disasters and political institutions

This thesis examines how natural disasters—earthquakes, floods and storms—affect democracy by altering economic outcomes. The results indicate that earthquakes and floods improve the level of democracy, while storms lead to non-democratic transitions, particularly in island countries.