Can decision field theory enhance our understanding of health-based choices? Evidence from risky health behaviors.

Discrete choice models are almost exclusively estimated assuming random utility maximization (RUM) is the decision rule applied by individuals. Recent studies indicate alternative behavioral assumptions may be more appropriate in health. Decision field theory (DFT) is a psychological theory of decision-making, which has shown promise in transport research.

Chemometric approaches to resolving base oil mixtures.

Rationale: In the lubrication industry, commercial base oils are commonly made up of blends of base oil stocks from different sources in different ratios to reduce production costs and modulate rheological properties. This practice introduces complexity in lubricant design because as the chemistry of the base oil becomes more complicated, it can become harder to formulate the base oil - particularly when the ratio of the original base oil stocks is unknown.

Methods: In this study, field ionisation mass spectrometry is used to collect chemical information on a range of base oil mixtures.

Physiological vagility affects population genetic structure and dispersal and enables migratory capacity in vertebrates.

Vagility is defined as the relative capacity for movement. We developed previously a quantitative metric in vertebrates for physiological vagility (PV), the speed at which an animal can move sustainably, incorporating aerobic capacity, body size, body temperature, and transport costs, allowing quantitative tests of whether PV can explain variation in interclass population genetic structure and behaviors involved in dispersal. We found that PV increased with body mass, correlated with maximal dispersal distances, and was inversely related to genetic structure in multiple vertebrate groups.

Metabolism at the Max: How Vertebrate Organisms Respond to Physical Activity.

Activity metabolism is supported by phosphorylated reserves (adenosine triphosphate, creatine phosphate), glycolytic, and aerobic metabolism. Because there is no apparent variation between vertebrate groups in phosphorylated reserves or glycolytic potential of skeletal muscle, variation in maximal metabolic rate between major vertebrate groups represents selection operating on aerobic mechanisms. Maximal rates of oxygen consumption in vertebrates are supported by increased conductive and diffusive fluxes of oxygen from the environment to the mitochondria.

Physiological vagility and its relationship to dispersal and neutral genetic heterogeneity in vertebrates.

Vagility is the inherent power of movement by individuals. Vagility and the available duration of movement determine the dispersal distance individuals can move to interbreed, which affects the fine-scale genetic structure of vertebrate populations. Vagility and variation in population genetic structure are normally explained by geographic variation and not by the inherent power of movement by individuals.

Physiological vagility: correlations with dispersal and population genetic structure of amphibians.

Physiological vagility represents the capacity to move sustainably and is central to fully explaining the processes involved in creating fine-scale genetic structure of amphibian populations, because movement (vagility) and the duration of movement determine the dispersal distance individuals can move to interbreed. The tendency for amphibians to maintain genetic differentiation over relatively short distances (isolation by distance) has been attributed to their limited dispersal capacity (low vagility) compared with other vertebrates. Earlier studies analyzing genetic isolation and population differentiation with distance treat all amphibians as equally vagile and attempt to explain genetic differentiation only in terms of physical environmental characteristics.

A comparative meta-analysis of maximal aerobic metabolism of vertebrates: implications for respiratory and cardiovascular limits to gas exchange.

Maximal aerobic metabolic rates (MMR) in vertebrates are supported by increased conductive and diffusive fluxes of O(2) from the environment to the mitochondria necessitating concomitant increases in CO(2) efflux. A question that has received much attention has been which step, respiratory or cardiovascular, provides the principal rate limitation to gas flux at MMR? Limitation analyses have principally focused on O(2) fluxes, though the excess capacity of the lung for O(2) ventilation and diffusion remains unexplained except as a safety factor. Analyses of MMR normally rely upon allometry and temperature to define these factors, but cannot account for much of the variation and often have narrow phylogenetic breadth.

The role of vascular and interstitial compliance and vascular volume in the regulation of blood volume in two species of anuran.

The objectives of this study were (1) to measure plasma (V(p)), blood (V(b)), extracellular (V(e)), and interstitial fluid (V(ist)) volumes using the same techniques; (2) to measure the rate of plasma turnover; and (3) to characterize the three important variables required to interpret transvascular flux at an organismal level (vascular compliance [C(vas)], interstitial compliance [C(ist)], and the whole-body transvascular filtration coefficient [F(c)]) in two species of anurans that differ in their capacity to regulate blood volume during dehydrational and hemorrhagic stress. The disappearance curve of Evans blue-labeled native plasma protein fitted a two-component exponential decay model for both species, indicating that plasma proteins exchanged quickly between two kinetically distinct compartments, V(p) and V(e). V(p) calculated using serial sampling times <10 min were 61.

Contributions to elevated metabolism during recovery: dissecting the excess postexercise oxygen consumption (EPOC) in the desert iguana (Dipsosaurus dorsalis).

The excess postexercise oxygen consumption (EPOC), a measure of recovery costs, is known to be large in ectothermic vertebrates such as the desert iguana (Dipsosaurus dorsalis), especially after vigorous activity. To analyze the cause of these large recovery costs in a terrestrial ectotherm, Dipsosaurus were run for 15 s at maximal-intensity (distance 35.0+/-1.

Intermittent locomotor activity that increases endurance also increases metabolic costs in the desert Iguana (Dipsosaurus dorsalis).

Intermittent activity, alternating bouts of activity and rest, can extend endurance relative to continuous locomotion. Utilizing a rapid fatiguing activity intensity (1.08 m s(-1)), Dipsosaurus dorsalis (n = 14) ran repeated bouts of varying durations (5, 15, or 30 s) interspersed with variable pause periods (100%, 200%, 400%, or 800% of the activity period) until exhausted.

The influence of partial-match cues on event-based prospective memory.

In event-based prospective memory tasks people form an intention to respond when an environmental cue signals that conditions are appropriate to fulfil an intended activity. In the ongoing activity the authors embedded partial-match cues that only partially, but not completely, satisfied the conditions required to make a prospective response. The consequence of encountering these partial-match cues was to increase responses to appropriate prospective memory cues encountered later.

Another perspective on altitudinal limits of alpine timberlines.

Recent hypotheses of timberline causation include the possibility that limitations to growth processes may be more limiting than restrictions on photosynthetic carbon gain, and that cold soil is a primary limiting factor at high altitude. However, almost all of the supporting data for timberline causation have come from studies on older trees, with little focus on the mechanisms of seedling establishment and the growth of saplings away from the forest edge into the treeline ecotone. We describe a conceptual model of timberline migration that invokes a strong dependence on ecological facilitation, beginning with seed germination and continuing through seedling establishment and sapling growth to the stage where trees with forest-like stature form new subalpine forest at a higher altitude.

Measuring the activation level of critical lures in the Deese-Roediger-McDermott paradigm.

In four experiments, the activation level in memory of critical lures was assessed after encoding Deese-Roediger-McDermott (DRM) lists. The results demonstrated that studying longer, 14-item lists resulted in superadditive priming of the lures because they were more available in memory than truly studied items. Studying shorter DRM lists resulted in activation levels of the lures that was similar to studied items.

Backward associative strength determines source attributions given to false memories.

Source attributions for falsely remembered material were investigated in two experiments. A male and a female speaker each presented either an entire word list or half of the items from each of multiple Deese-Roediger-McDermott (DRM) lists commonly used in this paradigm. In the latter condition the tendency of each list half to activate a nonpresented, critical list theme item was manipulated.

The demands of an ongoing activity influence the success of event-based prospective memory.

Four experiments were conducted to evaluate whether event-based prospective memory would be sensitive to the concurrent demands of the ongoing activity in which intention-related cues were embedded. In Experiments 1 and 2, random alternation between two judgments in the ongoing task reduced prospective memory as compared with having a single task throughout. In Experiment 3, participants' making two binary judgments on every trial resulted in worse prospective memory than did their making single four-alternative judgments.

Metabolic implications of a 'run now, pay later' strategy in lizards: an analysis of post-exercise oxygen consumption.

Lizards and many other animals often engage in locomotor behaviors that are of such short duration that physiological steady-state conditions are not attained. It is sometimes difficult to estimate the energetic costs of this type of locomotor activity. This difficulty is addressed by considering as reflective of the metabolic cost of activity (C(act)) not only the oxygen consumed during the activity itself, but also the excess post-exercise oxygen consumption (EPOC) and any excess metabolites persisting at the end of EPOC.

Investigating the output monitoring component of event-based prospective memory performance.

The goal of this study was to augment the standard event-based prospective memory paradigm with an output monitoring component. That component involves memory for past actions and, in the context of prospective memory, is largely responsible for repetition and omission errors. The modified paradigm also provides an index of what people believe to be true concerning their past prospective memory performance.