Sarcoidosis: a prospective observational cohort from Northern Alberta.

Introduction: Sarcoidosis is a multi-system disease reported to occur with a higher incidence in Alberta than many other health jurisdictions within and outside of Canada. The reasons for this higher incidence are currently not known. Exposure to beryllium can result in a clinically and radiologically identical disease to sarcoidosis.

Polysomnography shows sleep fragmentation in patients with inactive inflammatory bowel disease.

Background: Inflammatory bowel disease (IBD), classified as Crohn's disease or ulcerative colitis, is a chronic inflammatory condition that affects the gastrointestinal tract. Fatigue is a common symptom of IBD, even in periods of inactive disease; however, the cause of this fatigue is unknown. Studies have suggested that altered sleep patterns may be associated with the fatigue experienced by IBD patients.

Does the New Zealand rockwren () hibernate?

In this study, we examined the thermal physiology of the endangered New Zealand rockwren (), a member of the Acanthisittidae, a family unique to New Zealand. This family, derived from Gondwana, is thought to be the sister taxon to all other passerines. Rockwrens permanently reside above the climatic timberline at altitudes from 1000 to 2900 m in the mountains of South Island.

What determines the basal rate of metabolism?

The basal rate of metabolism (BMR) is the most reported estimate of energy expenditure in endotherms. Its principal determinant is body mass, but BMR also correlates with a variety of behavioral and ecological factors that do not determine basal rate: they are byproducts of the mechanisms that are its determinate. In mammals, mass-independent BMR increases when muscle mass is >40% of total body mass and BMR is then ≥100% of the value expected from body mass.

The energetics of torpor in a temperate passerine endemic to New Zealand, the Rifleman (Acanthisitta chloris).

Compared to other birds, passerines, reflecting their small mass, have a narrow set of behavioral characteristics. One difference is that few enter torpor, especially in temperate environments. The few that do include swallows, none of which live throughout the year in cold-temperate environments, because their food, flying insects, is not available in winter and no passerine is known to hibernate.

The behavioral energetics of New Zealand's bats: Daily torpor and hibernation, a continuum.

We examine the impact of behavior on the short-term energy expenditures of the only terrestrial mammals endemic to New Zealand, two bats, the long-tailed (Chalinolobus tuberculatus, family Vespertilionidae), and the lesser short-tailed (Mystacina tuberculata, family Mystacinidae). Vespertilionidae has a world-wide distribution. Mystacinidae is restricted to New Zealand, although related to five neotropical families and one in Madagascar reflecting a shared Gondwanan origin of their Noctilionoidea superfamily.

The difficulty with correlations: Energy expenditure and brain mass in bats.

Brain mass has been suggested to determine a mammal's energy expenditure. This potential dependence is examined in 48 species of bats. A correlation between characters may be direct or derived from shared correlations with intervening factors without a direct interaction.

Avian energetics: The passerine/non-passerine dichotomy.

Whether passerines collectively have a higher mean mass-independent basal rate of metabolism than the mean of other birds has been controversial. The conclusion that no difference exists was based on phylogenetic analyses. Higher basal rates, however, have been repeatedly seen in passerines and demonstrated by ANCOVA analyses.

Geographic and temporal correlations of mammalian size reconsidered: a resource rule.

The tendency of mammals to increase or decrease body size with respect to geography or time depends on the abundance, availability, and size of resources. This dependency accounts for a change in mass with respect to geography, including latitude (Bergmann's rule), a desert existence, and life on oceanic islands (the island rule), as well as in a seasonal anticipation of winter (Dehnel's phenomenon) and a tendency for some lineages to increase in mass through time (Cope's rule). Such a generalized pattern could be called the "resource rule," reflecting the controlling effect of resource availability on body mass and energy expenditure.

Outcomes of home-based diagnosis and treatment of obstructive sleep apnea.

Background: Home diagnosis and therapy for obstructive sleep apnea (OSA) may improve access to testing and continuous positive airway pressure (CPAP) treatment. We compared subjective sleepiness, sleep quality, quality of life, BP, and CPAP adherence after 4 weeks of CPAP therapy in subjects in whom OSA was diagnosed and treated at home and in those evaluated in the sleep laboratory.

Methods: A randomized trial was performed consisting of home-based level 3 testing followed by 1 week of auto-CPAP and fixed-pressure CPAP based on the 95% pressure derived from the auto-CPAP device, and in-laboratory polysomnography (PSG) (using mostly split-night protocol) with CPAP titration; 102 subjects were randomized (age, 47.

Resources and energetics determined dinosaur maximal size.

Some dinosaurs reached masses that were approximately 8 times those of the largest, ecologically equivalent terrestrial mammals. The factors most responsible for setting the maximal body size of vertebrates are resource quality and quantity, as modified by the mobility of the consumer, and the vertebrate's rate of energy expenditure. If the food intake of the largest herbivorous mammals defines the maximal rate at which plant resources can be consumed in terrestrial environments and if that limit applied to dinosaurs, then the large size of sauropods occurred because they expended energy in the field at rates extrapolated from those of varanid lizards, which are approximately 22% of the rates in mammals and 3.

Seasonal energetics of northern phocid seals.

The metabolic rate of harp (Pagophilus groenlandicus), harbor (Phoca vitulina), and ringed seals (Pusa hispida) was measured at various temperatures in air and water to estimate basal metabolic rates (BMRs) in these species. The basal rate and body composition of three harp seals were also measured throughout the year to examine the extent to which they vary seasonally. Marine mammalian carnivores generally have BMRs that are over three times the rates expected from body mass in mammals generally, both as a response to a cold-water distribution and to carnivorous food habits with the basal rates of terrestrial carnivores averaging about 1.

Ecological factors affect the level and scaling of avian BMR.

The basal rate of metabolism (BMR) in 533 species of birds, when examined with ANCOVA, principally correlates with body mass, most of the residual variation correlating with food habits, climate, habitat, a volant or flightless condition, use or not of torpor, and a highland or lowland distribution. Avian BMR also correlates with migratory habits, if climate and a montane distribution is excluded from the analysis, and with an occurrence on small islands if a flightless condition and migration are excluded. Residual variation correlates with membership in avian orders and families principally because these groups are behaviorally and ecologically distinctive.

An analysis of the factors that influence the level and scaling of mammalian BMR.

The factors influencing the basal rate of metabolism (BMR) in 639 species of mammals include body mass, food habits, climate, habitat, substrate, a restriction to islands or highlands, use of torpor, and type of reproduction. They collectively account for 98.8% of the variation in mammalian BMR, but often interact in complex ways.

An empirical continuous positive airway pressure trial for suspected obstructive sleep apnea.

Background: Standard practice in obstructive sleep apnea (OSA) management requires that a positive diagnostic, overnight polysomnography (PSG) test be obtained before initiating treatment. However, long waiting times due to lack of access to PSG testing facilities may delay the initiation of definitive treatment for OSA.

Objectives: To evaluate the response of patients who had a high clinical suspicion for OSA and who were waiting for a PSG test to an empirical continuous positive airway pressure (CPAP) trial.

The energetics of reproduction in endotherms and its implication for their conservation.

The energy expenditure of endotherms, through its impact on the rate of reproduction, affects their ability to withstand competition, to tolerate environmental disturbances, and to endure predation. The fecundity of eutherian mammals increases with rate of metabolism because the post-natal growth rate increases and the gestation and conception-to-weaning periods decrease with a mass-independent increase in basal rate of metabolism. These correlations account for the observation that species that have large population fluctuations have high rates of metabolism and reproduction.

Flightless rails endemic to islands have lower energy expenditures and clutch sizes than flighted rails on islands and continents.

Data are presented on the standard energetics of six flighted and five flightless species of rails (Aves: Rallidae). The factors influencing these data and those from three additional species available from the literature, one of which was flightless, are examined. Basal rate of metabolism correlates with body mass, residency on islands or continents, volant condition, pectoral muscle mass, and food habits, but not with climate.

The relationship among flow rate, chamber volume and calculated rate of metabolism in vertebrate respirometry.

A relationship exists among the calculated rate of metabolism of an animal enclosed in a chamber, chamber volume and air flow rate. A "critical" flow rate, defined as the minimal flow rate that produces a complete mixture of chamber gases, characterizes each chamber/animal combination. At flow rates below the critical flow rate, calculated rates of metabolism decrease with flow rate and approach zero as flow rate approaches zero.

Food habits and the evolution of energetics in birds of paradise (Paradisaeidae).

Basal rates of metabolism, minimal thermal conductances, and body temperatures are reported for 13 species of birds of paradise that belong to nine genera. Body mass alone accounts for 91.7% of the variation in their basal rates.

Intraspecific allometry of standard metabolic rate in green iguanas, Iguana iguana.

To study the allometric relationship between standard metabolic rate and body mass (mass range 16-3627 g) in green iguanas, Iguana iguana (n=32), we measured rates of oxygen consumption (V(O(2))) at 30 degrees C during scotophase. The relationship could be described as: V(O(2))(ml h(-1))=0.478W(0.

Standard energetics of phyllostomid bats: the inadequacies of phylogenetic-contrast analyses.

The basal rates of metabolism (BMR) of bats belonging to the family Phyllostomidae are re-examined after an earlier correlation with food habits was rejected because it did not take phylogeny into consideration. This rejection was based on an erroneous attribution of food habits and on an analytical method, phylogenetic contrasts, that ignores interactions that occur among character states and preferentially attributes responsibility for character states to phylogeny. The re-examination made here was based on analysis of covariance, which makes no a priori assumptions on the relative impact of factors that influence character states and permits factor interactions to be identified.

The energetics of New Zealand's ducks.

Measurements on rates of metabolism and temperature regulation are presented from nine populations of seven species of ducks resident in New Zealand. An analysis of these data and those from 18 additional species obtained from the literature indicates that basal rate of metabolism in anatids correlates with body mass and restriction to the Australian-New Zealand region: these 'southern' species have basal rates that average 70% of those from the Northern Hemisphere. The low basal rates of southern anatids may reflect reduced pectoral muscle masses in association with the absence of migratory habits and/or life on land masses without eutherian predators.

Food habits and the basal rate of metabolism in birds.

The correlation of basal rate of metabolism with various factors is examined in birds. Chief among these is body mass. As in mammals, much of the remaining variation in basal rate among birds is associated with food habits.