Supercooling tolerance in the Mexican lizard Barisia imbricata (Squamata: Anguidae).

Environmental temperature impacts the physiological processes of reptiles, determines their hours of activity per day, and may constrain their ability to meet critical ecological requirements. When environmental temperatures reach freezing, a few lizard species exhibit two mechanisms (supercooling and freezing tolerance) to survive freezing, and these two processes depend on cryoprotective molecules, such as glucose. Organisms produce high glucose concentrations to reach lower than normal crystallisation points, and this blood glucose concentration can double after freezing.

Living in the mountains: Thermal ecology and freezing tolerance of the lizard Abronia taeniata (Squamata: Anguidae).

The impact of daily and seasonal variation in environmental temperature on lizards is important, since their physiological processes are body temperature dependent. Lizards that occupy mountainous areas must have been favoured to colonize such habitats through selection on thermal biology traits to thermoregulate effectively. Moreover, mountain lizards may be able to maintain their activity near their minimum critical temperature and even have antifreeze mechanisms.

Potential Distribution of L. in Mexico according to Its Optimal Thermal Range for Seed Germination under Different Climate Change Scenarios.

is a native tree of economic importance, as its wood is highly demanded in the international market. In this work, the current and future distributions of in Mexico under climate change scenarios were analyzed according to their optimal temperature ranges for seed germination. For the present distribution, 256 localities of the species' presence were obtained from the Global Biodiversity Information Facility (GBIF) database and modelled with MaxEnt.

Thermal Niche for Seed Germination and Species Distribution Modelling of King (Mahogany) under Climate Change Scenarios.

is an economically important tree species propagated by seeds that lose their viability in a short time, making seed germination a key stage for the species recruitment. The objective of this study was to determine the cardinal temperatures and thermal time for seed germination of ; and its potential distribution under different climate change scenarios. Seeds were placed in germination chambers at constant temperatures from 5 to 45 °C and their thermal responses modelled using a thermal time approach.

Environmental heterogeneity shapes physiological traits in tropical direct-developing frogs.

Tropical ectotherm species tend to have narrower physiological limits than species from temperate areas. As a consequence, tropical species are considered highly vulnerable to climate change since minor temperature increases can push them beyond their physiological thermal tolerance. Differences in physiological tolerances can also be seen at finer evolutionary scales, such as among populations of ectotherm species along elevation gradients, highlighting the physiological sensitivity of such organisms.

One hundred years of climate change in Mexico.

Spatial assessments of historical climate change provide information that can be used by scientists to analyze climate variation over time and evaluate, for example, its effects on biodiversity, in order to focus their research and conservation efforts. Despite the fact that there are global climatic databases available at high spatial resolution, they represent a short temporal window that impedes evaluating historical changes of climate and their impacts on biodiversity. To fill this gap, we developed climate gridded surfaces for Mexico for three periods that cover most of the 20th and early 21st centuries: t1-1940 (1910-1949), t2-1970 (1950-1979) and t3-2000 (1980-2009), and used these interpolated surfaces to describe how climate has changed over time, both countrywide and in its 19 biogeographic provinces.

The impact of global warming on the range distribution of different climatic groups of Aspidoscelis costata costata.

The ectothermic nature of reptiles makes them especially sensitive to global warming. Although climate change and its implications are a frequent topic of detailed studies, most of these studies are carried out without making a distinction between populations. Here we present the first study of an Aspidoscelis species that evaluates the effects of global warming on its distribution using ecological niche modeling.

[Respiratory function in allergic asthmatic children and its relation to the environmental pollen concentration].

Background: Bronchial asthma is the most common chronic disease in children, producing the highest absenteeism among children and adults.

Objective: To determine the relation between respiratory function in asthmatic children and contaminant and climatic environmental factors.

Material And Methods: It was performed a study with 26 asthmatic patients, from the Immuno-Allergies Department of the Specialties Hospital no.