John Reginald Brande Lighton

John Reginald Brande Lighton
Sable Systems International

Ph.D.

About

162
Publications
38,999
Reads
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6,739
Citations
Citations since 2016
38 Research Items
2076 Citations
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2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Introduction
My background is in comparative & metabolic physiology. A recovering academic, I juggle ongoing research collaborations with the development of advanced, high resolution metabolic & behavioral phenotyping systems designed from the perspective of a scientist rather than an engineer, emphasizing consummate analytical flexibility & unsurpassed temporal resolution. See my metabolic measurement textbook's website at www.respirometry.org (also the home of my seditious blog), my equally seditious twitter feed at www.twitter.com/sablesys, or my company's website at www.sablesys.com.
Additional affiliations
September 1995 - present
University of Nevada, Las Vegas
Position
  • Professor
Description
  • I have a research position at UNLV
January 1991 - August 1995
University of Utah
Position
  • Professor (Assistant)
January 1990 - December 1990
University of Zurich
Position
  • Guest Professor

Publications

Publications (162)
Article
Objective The aim of this study was to test whether increased energy expenditure (EE), independent of physical activity, reduces acute diet‐induced weight gain through tighter coupling of energy intake to energy demand and enhanced metabolic adaptations. Methods Indirect calorimetry and quantitative magnetic resonance imaging were used to assess e...
Preprint
Objective Long-term weight gain can result from cumulative small weight increases due to short-term excess caloric intake during weekends and holidays. Increased physical activity may mediate weight gain through increases in energy expenditure (EE) and reductions in energy balance. Current methods for modulating mouse EE (e.g. – exercise, chemical...
Article
Full-text available
Background Energy expenditure (EE) calculated from respirometric indirect calorimetry is most accurate when based on oxygen consumption (VO2), carbon dioxide production (VCO2) and estimated protein metabolism (PM). EE has a substantial dependence of ~7% on the respiratory quotient (RQ, VCO2/VO2) and a lesser dependence on PM, yet many studies have...
Preprint
Full-text available
I describe the abdomino-substratal tapping communication system of a Southern African tenebrionid beetle, Psammodes striatus (Fabricius, 1775) (Coleoptera: Tenebrionidae: Molurini), using computer simulation of tapping signals and computer-assisted acquisition of precise response timing data, augmented with data from natural beetle-beetle communica...
Chapter
This chapter discusses the most frequently used flow meters in respirometry. These include the volumetric rotameter, which is affected by ambient temperature and barometric pressure; and the mass flow meter, which directly measures the molar quantity of air passing through it, and thus automatically corrects the volume to standard temperature and p...
Chapter
Measuring oxygen consumption rates in aquatic media is the only practical method for determining the metabolic rates of cell cultures and aquatic organisms. This chapter describes the three principal variations of aquatic respirometry—closed and open system (or flow-through) respirometry, and headspace respirometry—together with procedures for cali...
Chapter
This chapter discusses ways of analyzing and presenting metabolic data while avoiding common mistakes. Topics covered include vital information often omitted from manuscripts; how to analyze the allometry of metabolic rate on mass; the mistake of reporting mass-specific or “mass-independent” metabolic rates; methods for quantifying differences betw...
Chapter
This chapter describes two approaches to human metabolic measurement: room calorimetry and dilution mode mask (or hood, or canopy) respirometry. For room calorimetry, where the EE of a subject is typically monitored for 24 h, strategies for arranging air flow systems and the convective air movement required for effective time constant compensation...
Chapter
All analyzers have strengths and limitations that vary with the technology used, and directly affect their suitability for different types of metabolic rate measurement. It is important for researchers to become familiar with the characteristics of the analyzer(s) they are using. This chapter discusses the chief technologies utilized in aerial gas...
Chapter
This chapter describes the basic theory behind the most widely used method for measuring metabolic rates: flow-through or open-system respirometry. The advantages and disadvantages of the technique are summarized and the two major types of flow-through respirometry systems are described. Recommendations are given on choosing an appropriate flow rat...
Book
Measuring Metabolic Rates demystifies the field of metabolic rate measurement, explaining every common variation of the art, from century-old manometric methods through ingenious syringe-based techniques, direct calorimetry, aquatic respirometry, stable-isotope metabolic measurement, and every type of flow-through respirometry. Each variation is de...
Chapter
This chapter describes the evolution of respirometry from Leonardo da Vinci’s musings onwards. The works of Boyle, the brilliant and prophetic Mayow, and the well-intentioned but misguided Priestley are described. The bizarre dead-end theory of phlogiston and its apparent validity to the scientists of the day are explained in historical context. Th...
Chapter
This chapter describes the theory and practical applications of coulometric respirometry. Coulometric respirometry is probably the most accurate method for measuring oxygen consumption rates. It is ideal for small animals and has the dual advantages of high sensitivity and the fact that the oxygen in the organism’s environment is not depleted, allo...
Chapter
This chapter discusses several often-neglected areas of respirometry infrastructure. These include the correct selection of scrubber chemicals for removing water vapor and/or carbon dioxide from air streams, without undesirable interactions; chemical-free scrubbing techniques such as selective membranes, thermal condensing systems, and mathematical...
Chapter
This chapter describes the setup, plumbing, and equations required for applying a respirometry system wherein the flow rate of the air entering the animal chamber is known. Such systems are usually referred to as push systems, because the air is usually pushed into a sealed respirometer chamber at a known rate, and the concentrations of incurrent a...
Chapter
This chapter describes the setup, plumbing, and equations for implementing a respirometry system wherein the flow rate of the air leaving the animal chamber is known. Such systems are usually referred to as pull systems, because the air is usually pulled from a chamber or mask at a known rate, and the concentrations of incurrent and excurrent gases...
Chapter
By using modern gas analyzers and variations of constant volume techniques described in Chapter 2, simple and high-throughput measurement of the metabolic rates of organisms ranging in size from bacteria to large insects and even small vertebrates are easily implemented. It is also possible to measure water loss rate and carbon dioxide production u...
Chapter
This chapter demystifies respirometry equations, showing how they can be derived using a simple mental trick: focusing the analysis on the principal gas that is neither consumed nor produced by animals. The effect of dilution of oxygen by carbon dioxide, the enrichment of carbon dioxide by the consumption of oxygen, and the effects of water vapor o...
Chapter
This chapter describes constant pressure (Gilson) and constant volume (Warburg) respirometry—long-established techniques that are still capable of accurate results. These are useful for measuring the metabolic rates of small organisms, cell cultures, and biochemical preparations. In Gilson respirometry, oxygen consumption is measured by reducing th...
Chapter
This chapter describes methods for validating the measurements made using flow-through respirometry. These methods include the injection of nitrogen at a known flow rate into a respirometry system; burning a small flame of ethanol or methanol at a rate measured by weighing the lamp (often called “alcohol recovery”); and burning hydrocarbon gases su...
Chapter
This chapter discusses useful skills and tools that can extend and amplify the reach of innovative researchers. These include programming languages; statistical packages; microcontrollers and single board computers; researcher-friendly electronic resources; circuit capture and printed circuit design packages and resources; 3D design and printing pa...
Chapter
This chapter describes calorimetry or the direct measurement of heat production, a technique first used by Lavoisier and Paulze for measuring metabolic rates. Bomb calorimetry—a technique for measuring the energy content of foods and other materials—is also described. The three most common applications of direct calorimetry—gradient, differential,...
Chapter
This chapter describes the development of metabolic phenotyping in biomedical research, providing a critical review of methodologies for air flow management, multiplexed versus continuous sampling, and the interaction between the cage time constant and sampling interval. The fact that the temporal resolution of a system is generally limited primari...
Chapter
This chapter describes various techniques for measuring metabolic rates of unrestrained organisms in the field. These include stable isotope techniques, which allow the accurate measurement of the carbon dioxide production of wild animals over an interval ranging from a few hours to several days. The main disadvantage of the method is that the meas...
Chapter
Metabolic measurements are sensitive to the activity level of the animal being measured. This chapter describes the various technologies available for recording the activity level of a study organism in synchrony with metabolic data, usually obtained using a flow-through system. These technologies include optical activity detection, in which inform...
Article
Full-text available
The range of thermal tolerance is one of the main factors influencing the geographic distribution of species. Climate change projections predict increases in average and extreme temperatures over the coming decades; hence, the ability of living beings to resist these changes will depend on physiological and adaptive responses. On an evolutionary sc...
Article
Full-text available
Physiological plasticity allows organisms to respond to diverse conditions. However, can being too plastic actually be detrimental? Malagasy common tenrecs, Tenrec ecaudatus, have many plesiomorphic traits and may represent a basal placental mammal. We established a laboratory population of T. ecaudatus and found extreme plasticity in thermoregulat...
Article
Full-text available
Exercise alone is often ineffective for treating obesity despite the associated increase in metabolic requirements. Decreased nonexercise physical activity has been implicated in this resistance to weight loss, but the mechanisms responsible are unclear. We quantified the metabolic cost of nonexercise activity, or "off-wheel" activity (OWA), and vo...
Article
Background: High-protein diets (HPDs) recently have been used to obtain body weight and fat mass loss and expand muscle mass. Several studies have documented that HPDs reduce appetite and food intake. Objective: Our goal was to determine the long-term effects of an HPD on body weight, energy intake and expenditure, and metabolic hormones. Methods:...
Poster
Full-text available
Indirect calorimetry is a first order, linear time invariant process. As such, the maximum temporal resolution attainable is principally determined by the time constant (tau) of the cage housing the experimental animal. This is equal to the volume of the cage divided by the flow rate pulled or pushed through it. Typical taus in metabolic phenotypin...
Article
Full-text available
Metabolic measurement of humans and model animals is an important aspect of biomedicine. Particularly, in the case of model animals, the limitations of currently widely used metabolic measurement methods are not widely understood. In this mini-review, I explain the theoretical underpinnings of flow-through respirometry as a linear time-invariant sy...
Chapter
Full-text available
In this chapter, I discuss techniques for increasing the robustness and accuracy of metabolic measurements, using as practical an approach as possible. After a short introduction to flow-through respirometry, the importance of the automated determination of incurrent in addition to excurrent gas concentrations during metabolic measurement, and the...
Article
Full-text available
Abstract The causes of thermal tolerance limits in animals are controversial. In many aquatic species, it is thought that the inability to deliver sufficient oxygen at high temperatures is more critical than impairment of molecular functions of the mitochondria. However, terrestrial insects utilize a tracheal system, and the concept of a mismatch b...
Article
Full-text available
![Figure][1] John Lighton discusses the 1981 paper by George Bartholomew, David Vleck and Carol Masters Vleck entitled: ‘Instantaneous measurements of oxygen consumption during pre-flight warm-up and post-flight cooling in sphingid and saturniid moths’. A copy of the paper can be
Article
Full-text available
Insects in general, and Drosophila in particular, are much more capable of surviving anoxia than vertebrates, and the mechanisms involved are of considerable biomedical and ecological interest. Temperature is likely to strongly affect both the rates of damage occurring in anoxia and the recovery processes in normoxia, but as yet there is no informa...
Article
Full-text available
Flow-through respirometry is a powerful, accurate methodology for metabolic measurement that is applicable to organisms spanning a body mass range of many orders of magnitude. Concentrating on flow-through respirometry that utilizes a chamber to contain the experimental animals, we describe the most common flow measurement and control methodologies...
Article
Full-text available
Indirect whole room calorimetry is commonly used in studies of human metabolism. These calorimeters can be configured as either push or pull systems. A major obstacle to accurately calculating gas exchange rates in a pull system is that the excurrent flow rate is increased above the incurrent flow rate, because the organism produces water vapor, wh...
Article
In Drosophila melanogaster and other insects, increases in atmospheric oxygen partial pressure (aPO(2)) tend to increase adult body size and decrease tracheal diameters and tracheolar proliferation. If changes in tracheal morphology allow for functional compensation for aPO(2), we would predict that higher aPO(2) would be associated with higher cri...
Article
Data on the discontinuous ventilation cycle and cost of pedestrian locomotion in female Dasymutilla gloriosa (Sauss.), a desert-dwelling mutillid, are described and compared with equivalent data from other Hymenoptera. The discontinuous ventilation cycle was intermediate between that found in xeric and mesic hymenopterans, with the open phase being...
Book
Full-text available
The measurement of metabolic rates is important in many areas of science. Examples range from ecology through a broad spectrum of physiological disciplines to biomedical fields such as genetic screening, obesity, and trauma research. The organisms being measured range in size from bacteria through insects to whales, and many different measurement m...
Article
. 1The seed-harvesting ant Messor (Veromessor) prrgandei (Mayr) is a common inhabitant of southwestern deserts of the U.S.A. Foragers vary in size from less than 1 mg to more than 10 mg in body mass and may travel over 80 m on a single foraging trip. Their small size, long foraging range, and hot, arid habitat suggest that water stress may limit fo...
Article
Full-text available
Foraging activity of ants in xeric areas may be limited by desiccation stresses. To assess the extent of such stresses on a polymorphic ant species [Messor pergandei (Mayr), body mass range 1-12mg], we measured body water reserves, absolute rates of water loss, and cuticular permeability over the species' foraging temperature range (15–45d̀C). Cuti...
Article
Little information exists on the energetics of locomotion in small insects, and none in small spiders. We examined standard rate of oxygen consumption (SV̊O2) and net cost of transport (NCOT) in Camponotus sericeiventris (Guerin), a formicine ant, Myrmecotypus rettenmeyeri(Unzicker), its clubionid spider mimic (mean masses 43 and 24 mg, respectivel...
Article
Full-text available
The discontinuous gas exchange cycle (DGC) of insects and other tracheate arthropods temporally decouples oxygen uptake and carbon dioxide emission and generates powerful concentration gradients for both gas species between the outside world and the tracheal system. Although the DGC is considered an adaptation to reduce respiratory water loss (RWL)...
Article
Flightless, diurnal tenebrionid beetles are commonly found in deserts. They possess a curious morphological adaptation, the subelytral cavity (an air space beneath the fused elytra) the function of which is not completely understood. In the tenebrionid beetle Eleodes obscura, we measured abdominal movements within the subelytral cavity, and the act...
Data
Not to scale. Nitrogen flow is adjusted to 250 ml/min when the solenoids are energized. The pump and flow meter (PUMP & FM) are set to 50 ml/minute. R = rotameter. NC = not connected. RC = Respirometry chamber. AMPC = Ascarite & magnesium perchlorate scrubber for removing CO2 and H2O. ADE = activity detector's emitter. ADD = activity detector's det...
Article
A recent study has shown that respiratory structures are disproportionately oversized in larger insects, and that oxygen supply to leg muscles may be physically constrained in the largest modern insects. High oxygen concentrations during the Carboniferous may have alleviated these physical constraints allowing the evolution of gigantic arthropods.
Article
Many, but not all, insects breathe in a discontinuous gas-exchange cycle. A recent study has evaluated rival hypotheses for the evolution of this trait, concluding that the most likely is the one invoking minimization of respiratory water loss.
Article
The upper critical thermal maximum (CTmax) of metazoans varies over a wide range, and its determinative factors, such as oxygen limitation, remain controversial. Induction of thermoprotective mechanisms after challenge by sublethal heat stress has been well documented in many organisms, including the model fly Drosophila melanogaster. Interestingly...
Article
Full-text available
The deleterious effects of anoxia followed by reperfusion with oxygen in higher animals including mammals are well known. A convenient and genetically well characterized small-animal model that exhibits reproducible, quantifiable oxygen reperfusion damage is currently lacking. Here we describe the dynamics of whole-organism metabolic recovery from...
Article
1The nutrient supply network model of the metabolic theory of ecology predicts that metabolic rate scales as mass0·75 at all hierarchical levels.2An alternative, cell size, model suggests that the scaling of metabolic rate is a by-product of the way in which body size changes, by cell size or number, or some combination thereof. It predicts a scali...
Article
Abstract Little attention has been given to the effect of physiological limitations on the ability of introduced species to invade ecological communities. In the present study, the water balance of the invasive Argentine ant (Linepithema humile) is compared with five common ant species native to southern California. Total and critical water content...
Article
Full-text available
Many adult and diapausing pupal insects exchange respiratory gases discontinuously in a three-phase discontinuous gas exchange cycle (DGC). We summarize the known biophysical characteristics of the DGC and describe current research on the role of convection and diffusion in the DGC, emphasizing control of respiratory water loss. We summarize the ma...
Article
Drosophila in flight show an unexpected cyclicity in gas exchange even at constant metabolic flux rates--perhaps because regular proboscis extensions assist in providing oxygen to the fly's brain.
Article
Full-text available
The ability of some insects to engage in complex orchestrations of tracheal gas exchange has been well demonstrated, but its evolutionary origin remains obscure. According to a recently proposed hypothesis, insects may employ spiracular control of gas exchange to guard tissues against long-term oxidative damage by using the discontinuous gas-exchan...
Article
Respiratory water loss (RWL) in insects showing continuous emission of CO(2) is poorly studied because few methodologies can measure it. Comparisons of RWL between insects showing continuous and discontinuous gas exchange cycles (DGC) are therefore difficult. We used two recently developed methodologies (the hyperoxic switch and correlation between...
Article
There is anecdotal evidence for profound behavioral changes prior to and during earthquakes in many organisms, including arthropods such as ants. Behavioral or physiological analysis has often, in light of these reports, been proposed as a means of earthquake prediction. We report here a serendipitous study of the effect of the powerful Landers ear...
Article
Full-text available
Partitioning the relative contributions of cuticular and respiratory water loss in a tracheate arthropod is relatively easy if it undergoes discontinuous gas exchange cycles or DGCs, leaving its rate of cuticular water loss in primary evidence while its spiracles are closed. Many arthropods are not so obliging and emit CO(2) continuously, making cu...
Article
Full-text available
The critical thermal maxima (CT(max)) of two sympatric, diurnal, thermophilic harvester ants from the Mojave Desert, USA (Pogonomyrmex rugosus and P. californicus) were measured by ramping their temperature upwards at a rate of 0.25 degrees C min(-1) during flow-through respirometry with optical activity detection. Rates of CO(2) emission ((CO(2)))...
Article
The energy cost of activities central to overall fitness in most animals, such as pedestrian locomotion, is traditionally measured in the laboratory and then extrapolated to field conditions for modeling or hypothesis-testing purposes. However, no accurate, direct, in situ validation of these extrapolations has been made on undisturbed animals. We...
Article
The discontinuous gas exchange cycle (DGC) of the pseudoscorpion Garypus californicus is characterized by periodic bursts of CO(2) emission and by high rates of interburst CO(2) emission. We investigated the mechanism that triggers the burst phase by manipulating ambient oxygen partial pressures (Po(2)). The ventilatory trigger in most land animals...
Article
Abstract The discontinuous gas exchange cycle, characterized by stringent spiracular control and periods of near-zero external CO2 emission separated by ‘bursts’ of CO2 emission, has evolved independently in several taxa of tracheate arthropods. These include the hexapoda, diplopoda, and several arachnid taxa; ticks, pseudoscorpions and solphugids....
Article
Full-text available
The discontinuous gas exchange cycle of the pseudoscorpion Garypus californicus, mean mass 5.9 mg, is rudimentary and is characterized by bursts of CO(2) at frequencies ranging from 3.6 mHz at 15 degrees C to 13.3 mHz at 35 degrees C. The mean volume of CO(2) emitted per burst is 3.6 micro l g(-1) at 25 degrees C, about a tenth of the amount emitte...
Article
The respiratory physiology and water relations of three harvester ant species (Pogonomyrmex rugosus Emery, P. occidentalis[Cresson] and P. californicus[Buckley]) were examined at three temperatures (15, 25 and 35°C) using a flow-through respirometry system. As intact ants tended to be active during testing, we performed a parallel set of experiment...
Article
Full-text available
Scorpions are abundant in arid areas, where their population biomass may exceed that of vertebrates. Since scorpions are predators of small arthropods and feed infrequently across multi-year lifespans, a parsimonious explanation for their observed, anomalously high biomass may be a depressed metabolic rate (MR). We tested the hypothesis that scorpi...
Article
Full-text available
The biochemical bases for the high mass-specific metabolic rates of flying insects remain poorly understood. To gain insights into mitochondrial function during flight, metabolic rates of individual flying honeybees were measured using respirometry, and their thoracic muscles were fixed for electron microscopy. Mitochondrial volume densities and cr...

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