Daily Body Temperature Research Articles

The Effect of Air Tourniquet on Interleukin-6 Levels in Total Knee Arthroplasty.

Background:Air tourniquet-induced skeletal muscle injury increases the concentrations of some cytokines such as interleukin-6 (IL-6) in plasma. However, the effect of an air tourniquet on the IL-6 concentrations after total knee arthroplasty (TKA) is unclear. We therefore investigated the impact of tourniquet-induced ischemia and reperfusion injury in TKA using the IL-6 level as an index.Methods:Ten patients with primary knee osteoarthrosis who underwent unilateral TKA without an air tourniquet were recruited (Non-tourniquet group). We also selected 10 age- and sex-matched control patients who underwent unilateral TKA with an air tourniquet (Tourniquet group). Venous blood samples were obtained at 3 points; before surgery, 24 h after surgery, and 7 days after surgery.The following factors were compared between the two groups; IL-6, C-reactive protein (CRP), creatine phosphokinase (CPK), the mean white blood cell (WBC) counts, and the maximum daily body temperatures.Results:The IL-6 level at 24 h after surgery was significantly higher than that at any other point (p<0.01). No significant differences were observed in the WBC count, the body temperature, or the CRP, CPK, or IL-6 levels of the two groups at any of the time points.Conclusion:The effect of ischemia and reperfusion due to the use of an air tourniquet on increasing the IL-6 level was much smaller than that induced by surgical stress in TKA.

Evaluation of the effectiveness of selected natural fertility symptoms used for contraception: estimation of the Pearl index of Lady-Comp, Pearly and Daysy cycle computers based on 10 years of observation in the Polish market.

Cycle computers are medical devices which use sophisticated statistical methods in addition to a comprehensive on-board database. Their main function is to precisely indicate the fertile and infertile phases of the menstrual cycle, based on daily basal body temperature measurements. A recent medical research program aimed at evaluating the EFFECTIVENESS of cycle computers for contraceptive purposes was conducted. This study was conducted between May and June 2016 on 3,450 Polish women. The Polish distributor sent an anonymous questionnaire to the participants. To date, 361 women, representing 17,322 cycles have returned accurately completed questionnaires. In the resultant group only 4 unintended pregnancies were observed, resulting in a Pearl index of 0.4989. This suggests that fewer than 5 in 1000 women, who use a cycle computer correctly over a period of one year, may become pregnant unintentionally. This result is slightly better than the results from 2010, when the Pearl index was 0.64. The results obtained from the study indicate that the effectiveness of cycle computers for contraceptive purposes is comparable with other methods, such as hormonal contraception, and therefore cycle computers can be recommended for women who either cannot use or do not wish to use traditional contraception. These results confirm the effectiveness of using natural fertility symptoms, such as basal body temperature changes in the context of cycle computer technology for the purposes of contraception.

Estimation of Circadian Body Temperature Rhythm Based on Heart Rate in Healthy, Ambulatory Subjects.

Core body temperature is a reliable marker for circadian rhythm. As characteristics of the circadian body temperature rhythm change during diverse health problems, such as sleep disorder and depression, body temperature monitoring is often used in clinical diagnosis and treatment. However, the use of current thermometers in circadian rhythm monitoring is impractical in daily life. As heart rate is a physiological signal relevant to thermoregulation, we investigated the feasibility of heart rate monitoring in estimating circadian body temperature rhythm. Various heart rate parameters and core body temperature were simultaneously acquired in 21 healthy, ambulatory subjects during their routine life. The performance of regression analysis and the extended Kalman filter on daily body temperature and circadian indicator (mesor, amplitude, and acrophase) estimation were evaluated. For daily body temperature estimation, mean R-R interval (RRI), mean heart rate (MHR), or normalized MHR provided a mean root mean square error of approximately 0.40 °C in both techniques. The mesor estimation regression analysis showed better performance than the extended Kalman filter. However, the extended Kalman filter, combined with RRI or MHR, provided better accuracy in terms of amplitude and acrophase estimation. We suggest that this noninvasive and convenient method for estimating the circadian body temperature rhythm could reduce discomfort during body temperature monitoring in daily life. This, in turn, could facilitate more clinical studies based on circadian body temperature rhythm.

The Association between Self-Monitored Reproductive Parameters, Pregnancy Outcomes and Acupuncture Treatment

Many women track their daily basal body temperature (BBT), an important factor in reproductive status, as a part of fertility self-management. This study involved 135 patients who had undergone conventional infertility treatment; they had weekly acupuncture treatment and we assessed BBT, menstrual cycle, menstrual period and menstrual bleeding amount pre- and post-treatment. We also analyzed the rate of insufficient description of reproductive parameters, comparing patients who had delivered a baby with those who had a miscarriage and those who did not become pregnant. Menstrual cycle and period did not show notable changes pre- and post-acupuncture treatment in all groups. Menstrual bleeding amount decreased in the no-pregnancy group. There was a suggestion that acupuncture decreased very long menstrual cycle (e.g. bimonthly) to monthly. The insufficient description rate of menstrual bleeding amount was high in all groups. Weekly discussion about monitoring reproductive parameters could improve patients’ awareness in self-management. To prevent miscarriage patients needed psychological and medical advice for careful self-management in pregnancy and menstrual cycle.

The effects of graded levels of calorie restriction: III. Impact of short term calorie and protein restriction on mean daily body temperature and torpor use in the C57BL/6 mouse.

A commonly observed response in mammals to calorie restriction (CR) is reduced body temperature (Tb). We explored how the Tb of male C57BL/6 mice responded to graded CR (10 to 40%), compared to the response to equivalent levels of protein restriction (PR) over 3 months. Under CR there was a dynamic change in daily Tb over the first 30-35 days, which stabilized thereafter until day 70 after which a further decline was noted. The time to reach stability was dependent on restriction level. Body mass negatively correlated with Tb under ad libitum feeding and positively correlated under CR. The average Tb over the last 20 days was significantly related to the levels of body fat, structural tissue, leptin and insulin-like growth factor-1. Some mice, particularly those under higher levels of CR, showed periods of daily torpor later in the restriction period. None of the changes in Tb under CR were recapitulated by equivalent levels of PR. We conclude that changes in Tb under CR are a response only to the shortfall in calorie intake. The linear relationship between average Tb and the level of restriction supports the idea that Tb changes are an integral aspect of the lifespan effect.

Streptozotocin-induced diabetes disrupts the body temperature daily rhythm in rats.

BackgroundIn mammals, the temperature rhythm is regulated by the circadian pacemaker located in the suprachiasmatic nuclei, and is considered a “marker rhythm”. Melatonin, the pineal gland hormone, is a major regulator of the endogenous rhythms including body temperature. Its production is influenced by many factors, such as type 1 diabetes mellitus. In rats, diabetes leads to hypothermia and reduced melatonin synthesis; insulin treatment reestablishes both.AimTo study the body temperature daily rhythm of diabetic animals and the effects of insulin and/or melatonin treatment on its structure.MethodsWe studied the effects of streptozotocin-induced diabetes (60 mg/kg) on the body temperature rhythm of Wistar rats and the possible modifications resulting from early and late treatments with insulin (6U/day) and/or melatonin (daily 0.5 mg/kg). We monitored the daily body temperature rhythm, its rhythmic parameters (MESOR, amplitude and acrophase), glycemia and body weight for 55 days. Data were classified by groups and expressed as mean ± SEM. One-way ANOVA analysis was performed followed by Bonferroni posttest. Statistical significance was set at p < 0.05.ResultsDiabetes led to complete disruption of the temperature rhythm and hypothermia, which were accentuated over time. All early treatments (insulin or/and melatonin) prevented the temperature rhythm disruption and hypothermia. Insulin plus melatonin restored the body temperature rhythm whereas insulin alone resulted less efficient; melatonin alone did not restore any of the parameters studied; however, when supplemented close to diabetes onset, it maintained the temperature rhythmicity. All these corrective effects of the early treatments were dependent on the continuous maintenance of the treatment.ConclusionsTaken together, our findings show the disruption of the body temperature daily rhythm, a new consequence of insulin-dependent diabetes, as well as the beneficial effect of the complementary action of melatonin and insulin restoring the normal rhythmicity.Electronic supplementary materialThe online version of this article (doi:10.1186/s13098-015-0035-2) contains supplementary material, which is available to authorized users.

Using biomimetic loggers to measure interspecific and microhabitat variation in body temperatures of rocky intertidal invertebrates

Until recently, marine scientists have relied heavily on satellite sea surface temperatures and terrestrial weather stations as indicators of the way in which the thermal environment, and hence the body temperatures of organisms, vary over spatial and temporal scales. We designed biomimetic temperature loggers for three species of rocky intertidal invertebrates to determine whether mimic body temperatures differ from the external environment and among species and microhabitats. For all three species, microhabitat temperatures were considerably higher than the body temperatures, with differences as great as 11.1°C on horizontal rocky substrata. Across microhabitats, daily maximal temperatures of the limpet Cellana tramoserica were on average 2.1 and 3.1°C higher than body temperatures of the whelk Dicathais orbita and the barnacle Tesseropora rosea respectively. Among-microhabitat variation in each species’ temperature was equally as variable as differences among species within microhabitats. Daily maximal body temperatures of barnacles placed on southerly facing vertical rock surfaces were on average 2.4°C cooler than those on horizontal rock. Likewise, daily maximal body temperatures of whelks were on average 3.1°C cooler within shallow rock pools than on horizontal rock. Our results provide new evidence that unique thermal properties and microhabitat preferences may be important determinants of species’ capacity to cope with climate change.

Characterization of postoperative fevers after hemispherotomy.

Patients who have undergone hemispherotomy for intractable epilepsy tend to develop postoperative fevers, which can be severe and/or prolonged, for unclear reasons. The purpose of this paper is to characterize postoperative fever curves after hemispherotomy based on factors including seizure etiology, perioperative blood loss, and the presence or absence of ventricular drainage. We present 72 patients who underwent hemispherotomy at our institution between 1995 and 2013 by four surgeons. Data including daily maximum body temperature, seizure etiology, ventricular drain use, steroid and antipyretic use, and seizure control were gathered retrospectively based on electronic records including operative summaries, nursing notes, discharge summaries, and follow-up clinic notes. Seventy-two patients from 11 weeks to 21 years old (mean 7.4 years old) underwent hemispherotomy between 1995 and 2013. Sixty (83%) had fevers postoperatively, while the remainder were afebrile. Patients without external ventricular drains had higher and more prolonged fevers compared to those with drains (p = 0.003). Patients with Rasmussen's encephalitis tended to have higher postoperative fevers than patients with other seizure etiologies (p = 0.005), while patients with cortical dysplasia and polymicrogyria tended to have less severe fevers (p = 0.027 and 0.017, respectively). Fifty-five patients (76%) had freedom from disabling seizures (Engel class I), and 96% showed worthwhile improvement or better (Engel classes I-III). Postoperative fever can be anticipated in hemispherotomy patients, may vary based on certain seizure etiologies, and may be mitigated by routinely utilizing external ventricular drainage. Hemispherotomy is an effective surgical procedure for intractable epilepsy in selected patients.

Changes in behaviour of dairy cows with clinical mastitis

Behaviour is an important tool for recognizing illness in animals. One of the most common diseases in dairy cattle is clinical mastitis. Evidence suggests that cows with this disease show sickness behaviours, but little is known about the progression of behavioural changes before and after the disease becomes clinical. The aims of this study were to determine changes in feeding and competitive behaviour at the feed bunk of dairy cows before the diagnosis of clinical mastitis and determine the effect of intramammary antibiotic treatment on behaviour. Dry matter intake, feeding time, number of visits to the feeder, rate of feed intake, number of replacements occurring at the feeder (when one cow displaced a feeding cow and took her position at the feed bin) and the percent of intake during peak feeding time were measured daily in eight cows diagnosed with clinical mastitis in one quarter of the udder. Clinical mastitis was diagnosed based on daily rectal body temperature as well as condition of the foremilk and udder assessed by the milker at each milking from calving until 30 days in milk. Starting on the day of diagnosis, cows received an intramammary antibiotic twice daily for three consecutive days. During the 5 days period before diagnosis, cows decreased feed intake by 1.2kg/d (SE=0.2, P<0.001) but showed no other changes in feeding behaviour during this time. The frequency of competitive replacements at the feeder (slope=−2.3 no./d, SE=1.0, P=0.04) and the percentage of intake at peak feeding time (slope=−1.8%, SE=0.6, P=0.008) were lower compared to day of diagnosis. Following treatment, cows immediately increased feed intake, feeding time and competitive replacements at the feeder. These results show that cows with naturally occurring clinical mastitis exhibit signs of sickness behaviour in the days before diagnosis, and that these behaviours rapidly recover in the days after treatment.

Estimation of body temperature rhythm based on heart activity parameters in daily life.

Body temperature contains valuable health related information such as circadian rhythm and menstruation cycle. Also, it was discovered from previous studies that body temperature rhythm in daily life is related with sleep disorders and cognitive performances. However, monitoring body temperature with existing devices during daily life is not easy because they are invasive, intrusive, or expensive. Therefore, the technology which can accurately and nonintrusively monitor body temperature is required. In this study, we developed body temperature estimation model based on heart rate and heart rate variability parameters. Although this work was inspired by previous research, we originally identified that the model can be applied to body temperature monitoring in daily life. Also, we could find out that normalized Mean heart rate (nMHR) and frequency domain parameters of heart rate variability showed better performance than other parameters. Although we should validate the model with more number of subjects and consider additional algorithms to decrease the accumulated estimation error, we could verify the usefulness of this approach. Through this study, we expect that we would be able to monitor core body temperature and circadian rhythm from simple heart rate monitor. Then, we can obtain various health related information derived from daily body temperature rhythm.

Factors affecting date of implantation, parturition, and den entry estimated from activity and body temperature in free-ranging brown bears.

Knowledge of factors influencing the timing of reproduction is important for animal conservation and management. Brown bears (Ursus arctos) are able to vary the birth date of their cubs in response to their fat stores, but little information is available about the timing of implantation and parturition in free-ranging brown bears. Body temperature and activity of pregnant brown bears is higher during the gestation period than during the rest of hibernation and drops at parturition. We compared mean daily body temperature and activity levels of pregnant and nonpregnant females during preimplantation, gestation, and lactation. Additionally we tested whether age, litter size, primiparity, environmental conditions, and the start of hibernation influence the timing of parturition. The mean date of implantation was 1 December (SD = 12), the mean date of parturition was 26 January (SD = 12), and the mean duration of the gestation period was 56 days (SD = 2). The body temperature of pregnant females was higher during the gestation and lactation periods than that of nonpregnant bears. The body temperature of pregnant females decreased during the gestation period. Activity recordings were also used to determine the date of parturition. The parturition dates calculated with activity and body temperature data did not differ significantly and were the same in 50% of the females. Older females started hibernation earlier. The start of hibernation was earlier during years with favorable environmental conditions. Dates of parturition were later during years with good environmental conditions which was unexpected. We suggest that free-ranging pregnant brown bears in areas with high levels of human activities at the beginning of the denning period, as in our study area, might prioritize investing energy in early denning than in early parturition during years with favorable environmental conditions, as a strategy to prevent disturbances caused by human.

The effect of consignment to broodmare Sales on physiological stress measured by faecal glucocorticoid metabolites in pregnant Thoroughbred mares

BackgroundValidation of a method for the minimally-invasive measurement of physiological stress will help understanding of risk factors that may contribute to stress-associated events including recrudescence of Equid herpesvirus (EHV), which is anecdotally associated with sales consignment of pregnant Thoroughbred mares. In this study we compared two similar groups of late-gestation Thoroughbred broodmares on the same farm: a consigned Sales group (N = 8) and a non-consigned Control group (N = 6). The Sales mares were separated from their paddock companions and grouped prior to their preparation for, transport to, and return from the sales venue. Both groups were monitored by sampling at regular intervals from 5 days prior to until 14 days after the sales date (D0) to measure physiological stress in terms of changes in faecal glucocorticoid metabolite (FGM) concentrations, and for event-related viral recrudescence via daily body temperature measurements and periodic nasal swabs for PCR analysis for EHV-1 and -4 DNA.ResultsIn both groups, FGM levels increased post-sales before returning to pre-sales levels. Specifically, FGM concentrations in the Sales mares were significantly higher on D + 3 and D + 10 than on D-4 and D-3 (F = 12.03, P < 0.0001, Post hoc: P = 0.0003 – 0.0008) and in the Control group FGM concentrations were higher on D + 10 than D-4 (F = 5.52, P = 0.004, Post hoc: P = 0.005). Interestingly, mean FGM levels in Control mares were significantly higher at 4 of the 5 sampling points (t = 5.64 – 2.25, p = 0.0001 – 0.044). Only one (Sales) mare showed PCR evidence of EHV-1 shedding.ConclusionsUsing FGM to measure physiological stress was supported by the increases observed in all mares after Sales consignment, including those not consigned to the sale. Monitoring FGM levels therefore represents an appropriate, minimally-invasive method for future studies to assess the contribution of physiological stress to EHV recrudescence in horses transported to sales or equestrian events.

The nuclear receptor Rev-erbα controls circadian thermogenic plasticity

Circadian oscillation of body temperature is a basic, evolutionary-conserved feature of mammalian biology1. Additionally, homeostatic pathways allow organisms to protect their core temperatures in response to cold exposure2. However, the mechanism responsible for coordinating daily body temperature rhythm and adaptability to environmental challenges is unknown. Here we show that the nuclear receptor Rev-erbα, a powerful transcriptional repressor, links circadian and thermogenic networks through the regulation of brown adipose tissue (BAT) function. Mice exposed to cold fare dramatically better at 5 AM (Zeitgeber time 22) when Rev-erbα is barely expressed than at 5 PM (ZT10) when Rev-erbα is abundant. Deletion of Rev-erbα markedly improves cold tolerance at 5 PM, indicating that overcoming Rev-erbα-dependent repression is a fundamental feature of the thermogenic response to cold. Physiological induction of uncoupling protein 1 (UCP1) by cold temperatures is preceded by rapid down-regulation of Rev-erbα in BAT. Rev-erbα represses UCP1 in a brown adipose cell-autonomous manner and BAT UCP1 levels are high in Rev-erbα-null mice even at thermoneutrality. Genetic loss of Rev-erbα also abolishes normal rhythms of body temperature and BAT activity. Thus, Rev-erbα acts as a thermogenic focal point required for establishing and maintaining body temperature rhythm in a manner that is adaptable to environmental demands.

Entrainment of Spontaneously Hypertensive Rat Fibroblasts by Temperature Cycles

The functional state of the circadian system of spontaneously hypertensive rats (SHR) differs in several characteristics from the functional state of normotensive Wistar rats. Some of these changes might be due to the compromised ability of the central pacemaker to entrain the peripheral clocks. Daily body temperature cycles represent one of the important cues responsible for the integrity of the circadian system, because these cycles are driven by the central pacemaker and are able to entrain the peripheral clocks. This study tested the hypothesis that the aberrant peripheral clock entrainment of SHR results from a compromised peripheral clock sensitivity to the daily temperature cycle resetting. Using cultured Wistar rat and SHR fibroblasts transfected with the circadian luminescence reporter Bmal1-dLuc, we demonstrated that two consecutive square-wave temperature cycles with amplitudes of 2.5°C are necessary and sufficient to restart the dampened oscillations and entrain the circadian clocks in both Wistar rat and SHR fibroblasts. We also generated a phase response curve to temperature cycles for fibroblasts of both rat strains. Although some of the data suggested a slight resistance of SHR fibroblasts to temperature entrainment, we concluded that the overall effect it too weak to be responsible for the differences between the SHR and Wistar in vivo circadian phenotype.

A gasless laparoscopic technique of wide excision for gastric gastrointestinal stromal tumor versus open method

BackgroundTraditional open surgery for gastrointestinal stromal tumors (GIST) requires a long incision. Moreover, the gas-filling laparoscopic technique used in GIST surgery still has its limitations. Therefore, we developed a gasless laparoscopic (GL) surgery for GIST and compared it with traditional open surgery.MethodsBetween October 2007 and September 2009, 62 GIST patients in the National Taiwan University Hospital received wide excisions. Of these 62 patients, 30 underwent the new procedure (GL group) and 32 had open surgery (OS group). Preoperative and postoperative clinicopathologic characteristics were compared between the groups.ResultsThere were no significant differences in preoperative characteristics or blood loss. However, the days to first flatus, postoperative hospital stay, wound length, white blood cell count at postoperative day one, and peak daily body temperature were all significantly improved in the GL group. Usage of postoperative analgesia on postoperative days one to five was also significantly lower in the GL group.ConclusionsWide-excision laparoscopy for gastric GIST can be performed more safely, more effectively, and with faster postoperative recovery using the gasless technique as compared with the open method. We, therefore, recommend this new surgical technique, which hybridizes the advantages of both the traditional open method and pure laparoscopic surgery.

Educational and Mortal Supports of Pediatric Heart Transplant Recipients in Osaka University Hospital

Objectives: Adherence to the medical regimen is widely considered to be critical in order to avert late rejection episodes, graft loss, patient death, and decrease medical costs following heart transplantation (HTx). In order to reduce medical nonadherence, pediatric recipients should be managed educationally and mortally as well as medically. In the present study, our management of 27 pediatric HTx recipients was reviewed retrospectively. Patients and method: 27 pediatric HTx recipients managed in Osaka University Hospital between 1992 and 2011 were investigated. As Japanese Organ Transplant Act had not accepted brain dead organ donation from children under 15 years of age until 2010, only 4 children underwent HTx in our hospital, whereas in Loma Linda University (N=11), Columbia University (N=7) and the other foreign hospitals (N=5). The mean age at HTx was 8.7 years. Sixteen were younger than 10 years Thirteen were male. Underlying disease was dilated cardiomyopathy in 15, restrictive cardiomyopathy in 9 and others in 3. All children who underwent oversea HTx returned to our hospital before going back to home. After stabilizing doses of medication, the recipients and their parents were educated again about HTx, medication and complications after HTx under Japanese specific environment. They came to outpatient clinic monthly even children who lived far from Osaka. Daily medication, body weight, body temperature and blood pressure, if possible were recorded by themselves or their relatives, which were shown to the doctors and patient coordinators at the clinic. If any ebvents, such as viral infection of classmates, diarrhea etc, happened, they sent E-mail or called to our staffs. If the patient proceeded to the next stage of education, medical staffs went their school and guided teachers and other staffs taking care of the patient. To manage adolescent patients, inter-patient or parent communication was important. We suggested them to attend the Transplant Games or the Kid's camp in summer. Elder patient might support younger ones mortally. Results: The mean follow up after HTx was 6.3 years (5 months to 20 years). All except one who died of renal failure 11 years after HTx, survived. Patient survival after 10 and 15 years after HTx were 100 and 86%, respectively. Four worked fully. Nineteen went to school with full academic load (senior high school in 1, junior high school in 6, elementally school in 10 and kindergarten in 2). NYHA class was 1 in all. Three experienced post lymphproliferative disorder but were cured. One was considered to undergo reHTx because of graft coronary atheroscrelosis. One was considered to undergo hemodialysis. Although 2 girls experienced medical nonadherence and cellular rejection at 10 and 15 years of their age, respectively, they recovered and took medication steadily after the above intervention. Conlusion: Although the number of patients was small, educational and mortal support as well as strict medical management may play a role in reducing medical nonadherence and improving their quality of life and prolonging their survival after HTx in children.

Daily Scheduled High Fat Meals Moderately Entrain Behavioral Anticipatory Activity, Body Temperature, and Hypothalamic c-Fos Activation

When fed in restricted amounts, rodents show robust activity in the hours preceding expected meal delivery. This process, termed food anticipatory activity (FAA), is independent of the light-entrained clock, the suprachiasmatic nucleus, yet beyond this basic observation there is little agreement on the neuronal underpinnings of FAA. One complication in studying FAA using a calorie restriction model is that much of the brain is activated in response to this strong hunger signal. Thus, daily timed access to palatable meals in the presence of continuous access to standard chow has been employed as a model to study FAA in rats. In order to exploit the extensive genetic resources available in the murine system we extended this model to mice, which will anticipate rodent high fat diet but not chocolate or other sweet daily meals (Hsu, Patton, Mistlberger, and Steele; 2010, PLoS ONE e12903). In this study we test additional fatty meals, including peanut butter and cheese, both of which induced modest FAA. Measurement of core body temperature revealed a moderate preprandial increase in temperature in mice fed high fat diet but entrainment due to handling complicated interpretation of these results. Finally, we examined activation patterns of neurons by immunostaining for the immediate early gene c-Fos and observed a modest amount of entrainment of gene expression in the hypothalamus of mice fed a daily fatty palatable meal.

Simulated body temperature rhythms reveal the phase-shifting behavior and plasticity of mammalian circadian oscillators

The circadian pacemaker in the suprachiasmatic nuclei (SCN) of the hypothalamus maintains phase coherence in peripheral cells through metabolic, neuronal, and humoral signaling pathways. Here, we investigated the role of daily body temperature fluctuations as possible systemic cues in the resetting of peripheral oscillators. Using precise temperature devices in conjunction with real-time monitoring of the bioluminescence produced by circadian luciferase reporter genes, we showed that simulated body temperature cycles of mice and even humans, with daily temperature differences of only 3°C and 1°C, respectively, could gradually synchronize circadian gene expression in cultured fibroblasts. The time required for establishing the new steady-state phase depended on the reporter gene, but after a few days, the expression of each gene oscillated with a precise phase relative to that of the temperature cycles. Smooth temperature oscillations with a very small amplitude could synchronize fibroblast clocks over a wide temperature range, and such temperature rhythms were also capable of entraining gene expression cycles to periods significantly longer or shorter than 24 h. As revealed by genetic loss-of-function experiments, heat-shock factor 1 (HSF1), but not HSF2, was required for the efficient synchronization of fibroblast oscillators to simulated body temperature cycles.

Simulated aerial sprays for field cage evaluation of Beauveria bassiana and Metarhizium brunneum (Ascomycetes: Hypocreales) against Anabrus simplex (Orthoptera: Tettigoniidae) in Montana

Field efficacy of the entomopathogenic Ascomycetes Beauveria bassiana strain GHA and Metarhizium brunneum strain F52 was evaluated against nymphs of the Mormon cricket, Anabrus simplex. Fungi were applied with a new apparatus that allows simulated aerial sprays to 0.1-m2 areas in the field. The Mormon crickets were then individually housed in cylindrical, metal hardware cloth cages on treated grass. Both fungi demonstrated only marginal success in reducing immature Mormon cricket survival in the field cages. After 28 days, the field mortality of insects, corrected for control deaths, was 28 and 45% for B. bassiana and M. brunneum, respectively. Field-exposed but laboratory-incubated insects, however, suffered 90–100% mortality within 12 days with initial deaths occurring on Day 6 (Beauveria) or Day 5 (Metarhizium), indicating a lethal rate was applied and acquired by the crickets in the field. Potential daily body temperatures were determined for the entire post-treatment observation period using special thermal surrogates. High ambient temperatures and/or thermoregulation by Mormon crickets, in excess of the upper thermal limits of both fungi, prevented higher mortality from being expressed in the field. Thermal surrogates were used to develop models for predicting onset of mortality from infections. The surrogate data indicated mortality should begin between 8 and 26 days after treatment with M. brunneum and 11 and 33 days after treatment with B. bassiana. The timing of mortality in field cages was consistent with the upper boundaries of the temporal models developed from the thermal surrogates, i.e., at or after 28 days after treatment.

Does size matter? Comparison of body temperature and activity of free-living Arabian oryx (Oryx leucoryx) and the smaller Arabian sand gazelle (Gazella subgutturosa marica) in the Saudi desert

Heterothermy, a variability in body temperature beyond the normal limits of homeothermy, is widely viewed as a key adaptation of arid-adapted ungulates. However, desert ungulates with a small body mass, i.e. a relatively large surface area-to-volume ratio and a small thermal inertia, are theoretically less likely to employ adaptive heterothermy than are larger ungulates. We measured body temperature and activity patterns, using implanted data loggers, in free-ranging Arabian oryx (Oryx leucoryx, ±70 kg) and the smaller Arabian sand gazelle (Gazella subgutturosa marica, ±15 kg) inhabiting the same Arabian desert environment, at the same time. Compared to oryx, sand gazelle had higher mean daily body temperatures (F(1,6) = 47.3, P = 0.0005), higher minimum daily body temperatures (F(1,6) = 42.6, P = 0.0006) and higher maximum daily body temperatures (F(1,6) = 11.0, P = 0.02). Despite these differences, both species responded similarly to changes in environmental conditions. As predicted for adaptive heterothermy, maximum daily body temperature increased (F(1,6) = 84.0, P < 0.0001), minimum daily body temperature decreased (F(1,6) = 92.2, P < 0.0001), and daily body temperature amplitude increased (F(1,6) = 97.6, P < 0.0001) as conditions got progressively hotter and drier. There were no species differences in activity levels, however, both gazelle and oryx showed a biphasic or crepuscular rhythm during the warm wet season but shifted to a more nocturnal rhythm during the hot dry season. Activity was attenuated during the heat of the day at times when both species selected cool microclimates. These two species of Arabian ungulates employ heterothermy, cathemerality and shade seeking very similarly to survive the extreme, arid conditions of Arabian deserts, despite their size difference.