Genome sequence of Aedes aegypti, a major arbovirus vector

We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.     

Stem breakage of trees and energy dissipation during rockfall impacts

The capacity of individual trees to dissipate the energy released by rockfalls has previously only been quantified based on data obtained from static tree-pulling tests or from dynamic impact tests on wood samples. We predicted that these data are not representative of the maximum amount of energy that can be dissipated by living trees during rockfall impacts. To test this prediction, we carried out rockfall experiments on a forested slope in the French Alps. To calculate the rock's energy before and after impact, rockfalls were filmed digitally. The recordings of nine impacts causing instantaneous breakage of Abies alba Mill. trees were analyzed in detail. An exponential relationship between stem diameter at breast height (DBH) and the maximum amount of energy a tree can dissipate was highly correlated for all of our experimental data. We applied this relationship to other tree species based on published fracture energies. The relationships obtained for Cedrus spp., Fagus sylvatica L. and Picea abies (L.) Karst. were significantly correlated with data from other dynamic impact tests in the field and with maximum bending moments obtained from tree-pulling experiments. Multiple linear regressions showed that impact height influences the energy that will be dissipated by an A. alba tree, particularly for trees with a DBH less than 15 cm. For trees with a DBH greater than 15 cm, the effect of impact height was minimal up to a height of 1 m. There was a strong relationship between the amount of energy dissipated by a tree and the horizontal distance between the impact center and the vertical central axis of the tree.     

Gastrointestinal absorption and urinary excretion of trans-cinnamic and p-coumaric acids in rats

trans-Cinnamic acid (CIN) and p-coumaric acid (COU) are ingested by humans in their diet. While the metabolism and health benefits of CIN have been widely documented, little is known about its absorption sites, and there have been few studies dedicated to COU. The gastrointestinal sac technique demonstrated that CIN and COU are absorbed by all digestive organs in rats and partially transported via MCT-mediated carrier. Absorption was lowest in the stomach. Regardless of the organs that were studied, CIN was more efficiently absorbed than COU. After their individual oral administration to rats, CIN and COU were excreted in 0-24 h urine (0.3% and 23% of ingested CIN and COU, respectively). This suggests that COU was less metabolized than CIN. CIN and COU are absorbed across the digestive epithelium and subsequently interact with target tissues. Despite its lower gastrointestinal absorption, COU may have greater health benefits because it seems to be less metabolized than CIN.     

High gamma power is phase-locked to theta oscillations in human neocortex

We observed robust coupling between the high- and low-frequency bands of ongoing electrical activity in the human brain. In particular, the phase of the low-frequency theta (4 to 8 hertz) rhythm modulates power in the high gamma (80 to 150 hertz) band of the electrocorticogram, with stronger modulation occurring at higher theta amplitudes. Furthermore, different behavioral tasks evoke distinct patterns of theta/high gamma coupling across the cortex. The results indicate that transient coupling between low- and high-frequency brain rhythms coordinates activity in distributed cortical areas, providing a mechanism for effective communication during cognitive processing in humans.     

Presence of avian influenza risk birds in and around poultry free-range areas in relation to range vegetation and openness of surrounding landscape

Free-range areas contribute to the welfare of poultry. Chickens are most likely to use these areas if there is sufficient cover by trees. However, wild birds in free-range areas may infect the chickens with avian influenza (AI). This study aimed to investigate the relation between the presence of AI risk birds and woody vegetation within the range areas as well as in the landscape surrounding the range areas. During two seasons all wild birds were counted in the free-range areas of 11 poultry farms and their immediate surroundings. More high-risk birds were observed in free-range areas with less than 5% woody cover, compared to free-range areas with more woody cover. Furthermore, more high-risk birds were observed in the surroundings of free-range areas in open landscapes, compared to half-open landscapes. As for low-risk birds, no relation was found between woody cover or openness of the landscape and the presence of these birds in free-range areas or surroundings. However, interpretation of the results was hampered by the incomplete factorial design, which did not allow to differentiate between the effect of woody cover within the range area and openness of the surrounding landscape. The results of this pilot study need to be confirmed with further experimental research on the relation between the presence of AI risk birds and woody vegetation in and around poultry free-range areas.