Differences in Thermal Preference and Tolerance among Three Phrynocephalus Lizards (Agamidae) with Different Body Sizes and Habitat Use

We acclimated adults of two viviparous （Phrynocephalus guinanens＆ and P. vlangalii） and one oviparous （P. versicolor） species of toad-headed lizards （Agamidae） to 28 ℃, 33 ℃ and 38 ℃ to examine whether thermal preference （preferred body temperature, Tp） and thermal tolerance （critical thermal minimum, CTMin; critical thermal maximum, CTMax） were affected by acclimation temperature, and correlate with body size and habitat use. Both Tp and CTMax were highest in P. versicolor and lowest in P. vlangalii, with P. guinanensis in between. The two viviparous species did not differ in CTMin and thermal tolerance range, and they both were more resistant to low temperatures and had a wider range of thermal tolerance than the oviparous species. Both CTMin and CTMax shifted upward as acclimation temperature increased in all the three species. Tp was higher in the lizards acclimated to 33 ℃ than in those to 28 ℃ or 38 ℃. The range of thermal tolerance was wider in the lizards acclimated to 28 ℃ than in those to 33 ℃ or 38 ℃. The data showed that： 1） thermal preference and tolerance were affected by acclimation temperature, and differed among the three species of Phrynocephalus lizards with different body sizes and habitat uses; 2） both Tp and CTMax were higher in the species exchanging heat more rapidly with the environment, and CTMin was higher in the species using warmer habitats during the active season; and 3） thermal preference and tolerance might correlat with body size and habitat use in Phrynocephalus lizards.

Variable Thermal Comfort Index for Indoor Work Space in Office Buildings: A Study in Germany

International standards state the thermal comfort requirements that office spaces must comply with. These are based on a model developed by Prof. Paul Ole Fanger of the Centre for Indoor Environment and Energy, Denmark. Today, forty-year research shows an evolution in these experiences. The work presented here is to develop a tool to evaluate the thermal comfort of working environments of office buildings. A methodology is devised on the basis of on-site measurements and questionnaire responses. For measurements, a mobile unit equipped with sensors is used, whereas the questionnaire obtains user responses on thermal quality of the work space. The thermal conditions of thirty office buildings presenting different acclimatization systems have been surveyed. The correlation between objective and subjective data allows developing a formula that shows the thermal comfort level for a given environment as a function of local aspects. For the surveyed buildings, the resulting comfortable temperature was 23.3℃, and the minimum percentage of user individuals experiencing discomfort with such temperature was 7%.

Preparation and properties of polycrystalline silicon seed layers on graphite substrate

Polycrystalline silicon（poly-Si） seed layers were fabricated on graphite substrates by magnetron sputtering. It was found that the substrate temperature in the process of magnetron sputtering had an important effect on the crystalline quality,and 700℃was the critical temperature in the formation of Si（220） preferred orientation. When the substrate temperature is higher than 700℃,the peak intensity of X-ray diffraction（XRD） from Si（220） increases distinctly with the increasing of substrate temperature.Moreover,the XRD measurements indicate that the structural property and crystalline quality of poly-Si seed layers are determined by the rapid thermal annealing （RTA） temperatures and time.Specifically,a higher annealing temperature and a longer annealing time could enhance the Si（220） preferred orientation of poly-Si seed layers.

Behavioral thermoregulation is highly repeatable and unaffected by digestive status in Agama atra

The precision and the extent of behavioral thermoregulation are likely to provide fitness benefits to ectotherms.Yet the factors driving variation in selected or preferred body temperature(T_(set))and its usefulness as a proxy for optimal physiological temperature(Topt)are still debated.Although T_(set)is often conserved among closely related species,substantial variation at the individual,population and species level has also been reported.However,the repeatability(calculated as the intra-class correlation coefficient)of T_(set)is generally low.One factor that influences T_(set)is feeding status,with fed reptiles typically showing higher T_(set),a process thought to aid meal digestion.Here,using experiments simulating realistic feeding and fasting regimes in Agama atra,a heliothermic lizard from southern Africa,we test if T_(set)and its repeatability under these 2 states significantly differ.Daily T_(set)ranged from 33.7 to 38.4℃,with a mean(±SE)of 36.7±0.1℃ for fed and 36.6±0.1℃ for unfed individuals.Comparisons of repeatability showed that females tend to be more consistent in the selection of body temperature than males,but not significantly so regardless of feeding status.We report some of the highest repeatability estimates of T_(set)to date(full range:0.229–0.642),and that the weak positive effects of feeding status on T_(set)did not increase its repeatability.In conclusion,one of the major prerequisites for natural selection,consistent among-individual variation,is present,making the adaptive significance of T_(set)considerably more plausible.

Embryonic and post-embryonic responses to high-elevation hypoxia in a low-elevation lizard

Low-elevation species can migrate toward higher elevations to survive in a warming world.However,animals’responses to hypoxia when migrating to high elevations have rarely been addressed.To identify the response of lowelevation lizards to high-elevation hypoxia,we collected field body temperatures(Tfb)and operative temperatures(Te)of lizards(Eremias argus)from a low-elevation population(1036 m)and a high-elevation population(2036 m),and then determined adult thermal physiology,embryonic development,and hatchling phenotypes after acclimating low-elevation lizards and incubating their eggs in conditions mimicking the low-elevation oxygen condition(18.5%O2)and high-elevation oxygen(hypoxic)condition(16.5%O2).Our study revealed that Tfb and Te were higher for the low-elevation population compared to the high-elevation population.We also found adults from low elevation acclimated to hypoxia preferred lower body temperatures,but did not show changes in locomotor performance or growth.In addition,hypoxia did not affect embryonic development(hatching time and success)or hatchling phenotypes(body size and locomotor performance).These results suggest that adult lizards from low elevations can respond to hypoxia-induced stress when migrating to high elevations by behaviorally thermoregulating to lower body temperatures in order to sustain normal functions.Similarly,low-elevation embryos can develop normally(with unchanged hatching success and offspring phenotypes)under the high-elevation hypoxic condition.This study highlights that low-elevation populations of a species that inhabits a range of elevations can buffer the impact of high-elevation hypoxic conditions to some degree and thus attain similar fitness to the source population.