Level and precision of behavioural thermoregulation in the bearded dragon, Pogona vitticeps : effects of hypoxia and environmental thermal quality /

Most metabolic functions are optimized within a narrow range of body temperatures, which is why thermoregulation is of great importance for the survival and overall fitness of an animal. It has been proposed that lizards will thermoregulate less precisely in low thermal quality environments, where the costs associated with thermoregulation are high; in the case of lizards, whose thermoregulation is mainly behavioural, the primary costs ofthermoregulation are those derived from locomotion. Decreasing thermoregulatory precision in costly situations is a strategy that enhances fitness by allowing lizards to be more flexible to changing environmental conditions. It allows animals to maximize the benefits of maintaining a relatively high body temperature while minimizing energy expenditure. In situations where oxygen concentration is low, the costs of thermoregulation are relatively high (i.e. in relation to the amount of oxygen available for metabolic functions). As a result, it is likely that exposures to hypoxic conditions induce a decrease in the precision of thermoregulation. This study evaluated the effects of hypoxia and low environmental thermal quality, two energetically costly conditions, on the precision and level of thermoregulation in the bearded dragon, Pogona vitticeps, in an electronic temperature-choice shuttle box. Four levels of hypoxia (1O, 7, 5 and 4% 02) were tested. Environmental thermal quality was manipulated by varying the rate of temperature change (oTa) in an electronic temperature-choice shuttle box. Higher oT a's translate into more thermally challenging environments, since under these conditions the animals are forced to move a greater number of times (and hence invest more energy in locomotion) to maintain similar temperatures than at lower oTa's. In addition, lizards were tested in an "extreme temperatures" treatment during which air temperatures of the hot and cold compartments of the shuttle box were maintained at a constant 50 and 15°C respectively. This was considered the most thermally challenging environment. The selected ambient (T a) and internal body temperatures (Tb) of bearded dragons, as well as the thermoregulatory precision (measured by the central 68% ofthe Ta and T b distribution) were evaluated. The thermoregulatory response was similar to both conditions. A significant increase in the size of the Tb range, reflecting a decrease in thermoregulatory precision, and a drop in preferred body temperature of ~2 °C, were observed at both 4% oxygen and at the environment of lowest thermal quality. The present study suggests that in energetically costly situations, such as the ones tested in this study, the bearded dragon reduces energy expenditure by decreasing preferred body temperature and minimizing locomotion, at the expense of precise behavioural thermoregulation. The close similarity of the behavioural thermoregulatory response to two very different stimuli suggests a possible common mechanism and neuronal pathway to the thermoregulatory response.

Characterising Behavioural Thermoregulation in the Bearded Dragon: The Role of TRPM8

Temperature regulation is a necessary part of maintaining life, as most biological processes are influenced by temperature. ThermoTRP channels are considered the primary thermosensors in endotherms, but little is known regarding their function in ectotherms. The goal of this study is to establish TRPM8, a cold sensing channel, as a participant in normal thermoregulation of the bearded dragon (Pogona vitticeps), an ectotherm. Animals were placed inside a ramping temperature shuttle box to assess the common behavioural thermoregulatory strategy of shuttling. Shuttling involves the periodic movement between cold and warm environments to maintain body temperature at moderate levels. The temperatures for cold and warm escapes represent sensory thresholds for inducing the shuttling thermoeffector. Animals were administered with: 1) an injection of the TRM8 antagonist capsazepine, 2) an injection of the TRPM8 agonist menthol, and 3) menthol applied topically. No effect was observed with injected drugs, but topical menthol resulted in a 2-3oC rise in the ambient temperature threshold and 1-2oC rise in skin temperature threshold for escape from the cold compartment. In an additional experiment, gaping behaviour, a warm temperature thermoregulatory strategy, was assessed. No effect was observed in this behaviour when the same dose of menthol was applied topically. These results point to a role for TRPM8 only in thermoregulation as it relates to cold temperature sensation in lizards, since it does not participate in regulating warm temperature behaviours such as gaping.

Dompter le dragon : l’économie politique de la drogue et le conflit armé en Birmanie

Les conflits armés dans des pays producteurs de drogues illicites, comme la Birmanie, sont parmi les plus longs du XXe et du XXIe siècles. Dans ces conflits, l’industrie de la drogue est souvent présentée comme la source de financement qui permet aux groupes insurgés de poursuivre leur combat contre le gouvernement central. Cependant, l’économie illicite birmane s’est développée pendant un conflit armé tout comme durant une période de stabilité accrue. Une analyse des régions shan, wa et kokang de l’État Shan démontre que les industries de la drogue ont prospéré à la fois durant le conflit armé et en l’absence de celui-ci lorsque des ententes entre élites existent autour du partage des rentes de cette économie.

Healthy as a trout – as delicate as a dragon-fly

Travail créatif / Creative Work

The dragon tree.

Pertenece a un amplio programa infantil de lectura que abarca distintos niveles de edad y, por tanto, de conocimientos. Se abordan las necesidades de lectura en los niños y la amplia variedad de habilidades que necesitan adquirir para su aprendizaje y, se destaca, también, la importancia de la narración en las historias. Los niños protagonistas viven una aventura fantástica con un dragón que vive en un árbol.

The lord mount dragon.

Este un relato popular que refleja los mitos, leyendas, cuentos populares y cuentos de hadas de la cultura irlandesa. Cumple con los requisitos del currículo de Inglaterra, Gales e Irlanda. Las ilustraciones apoyan el texto, lo que permite a los alumnos predecir palabras desconocidas al desarrollar un vocabulario basado en las imágenes, pero se les ha dado una mayor libertad al añadirles más detalles. Hay una mayor variedad de tipos de texto y estructuras de las frases. Para leer en voz alta teniendo en cuenta la puntuación y la entonación. Para niños de seis a ocho años y motivarlos a explorar sus respuestas personales y enlazar con sus propias experiencias. Adecuado para lectura guiada.

Cooking with Herb, the vegetarian dragon : a cook book for kids.

En el bosque de Nogard, el dragón Meathooh y sus compinches piensan que nada es mejor que el sabor crujiente de caballeros con armadura hasta que un dragón vegetariano los tienta con otras recetas alternativas. Este no es un libro de recetas que puede ser utilizado por los niños sin la ayuda de adultos. Prácticamente la totalidad de las recetas requieren cortar con un cuchillo afilado y el uso del horno.

Competencia digital y literacidad : nuevos formatos narrativos en el videojuego 'Dragon Age : Orígenes'.

El artículo forma parte de una sección de la revista dedicada a: Investigaciones

When the rising dragon sees fading stars: China's view of the European Union. CEPS Special Report No. 73, 29 November 2012

This CEPS Special Report gives an overview of China’s perceptions of the EU and the protection of Chinese investments in Europe since the outbreak of the European sovereign debt crisis, especially since the more concrete talks in late 2011 on possible financial support from China. Although the top leadership of the communist party of China (CPC) changed in its recent handover, the perceptions described in this paper are likely to remain the same, just as the main tenets of China’s foreign policy are unlikely to change in the near future. The report argues that while the EU’s image has suffered greatly from the sovereign debt crisis and the way it has been handled, there is room to improve China’s view of Europe and for the EU to maintain a relatively strong negotiation position towards China.

Oligosaccharides of pitaya (dragon fruit) flesh and their prebiotic properties

The major carbohydrates of white and red-flesh pitayas (dragon fruit) were glucose, fructose and some oligosaccharides (total concentrations of 86.2 and 89.6 g/kg, respectively). The molecular weight distribution of the extract was affected by the extraction solvent. The maximum oligosaccharides content (27.40%), which included fractions with molecular weights of 273–275, 448–500 and 787–911 Da, were obtained using 80% ethanol extraction at room temperature (28 ± 2 °C). The low molecular weight fraction, including glucose and fructose, was successfully removed by yeast cultivation. The molecular weights of mixed oligosaccharides (716, 700, 490 and 474 Da) were confirmed by mass spectrometry. The mixed oligosaccharides showed that they were resistant to hydrolysis by artificial human gastric juice and human α-amylase, giving maximum hydrolysis of 4.04% and 34.88%, respectively. The mixed oligosaccharides were also found capable of stimulating the growth of lactobacilli and bifidobacteria.

The consumer litigation industry: chasing dragon kings in lawyer-client networks

The community of lawyers and their clients form a scale-free bipartite network that develops naturally as the outcome of the recommendation process through which lawyers form their client base. This process is an example of preferential attachment where lawyers with more clients are more likely to be recommended to new clients. Consumer litigation is an important market for lawyers. In large consumer societies, there always a signi cant amount of consumption disputes that escalate to court. In this paper we analyze a dataset of thousands of lawsuits, reconstructing the lawyer-client network embedded in the data. Analyzing the degree distribution of this network we noticed that it follows that of a scale-free network built by preferential attachment, but for a few lawyers with much larger client base than could be expected by preferential attachment. Incidentally, most of these also gured on a list put together by the judiciary of Lawyers which openly advertised the bene ts of consumer litigation. According to the code of ethics of their profession, lawyers should not stimulate clients into litigation, but it is not strictly illegal. From a network formation point of view, this stimulation can be seen as a separate growth mechanism than preferential attachment alone. In this paper we nd that this composite growth can be detected by a simple statistical test, as simulations show that lawyers which use both mechanisms quickly become the \Dragon-Kings" of the distribution of the number of clients per lawyer.