Modelling Infectious Hematopoietic Necrosis Virus Dispersion from Marine Salmon Farms in the Discovery Islands,British Columbia,Canada

Finite volume ocean circulation and particle tracking models are used to simulate water-borne transmission of infectious hematopoietic necrosis virus (IHNV) among Atlantic salmon (Salmo salar) farms in the Discovery Islands region of British Columbia, Canada. Historical simulations for April and July 2010 are carried out to demonstrate the seasonal impact of river discharge, wind, ultra-violet (UV) radiation, and heat flux conditions on near-surface currents, viral dispersion and survival. Numerical particles released from infected farm fish in accordance with IHNV shedding rates estimated through laboratory experiments are dispersed by model oceanic flows. Viral particles are inactivated by ambient UV radiation levels and by the natural microbial community at rates derived through laboratory studies. Viral concentration maps showing temporal and spatial changes are produced and combined with lab-determined minimum infectious dosages to estimate the infective connectivity among farms. Results demonstrate that neighbouring naïve farms can become exposed to IHNV via water-borne transport from an IHNV diseased farm, with a higher risk in April than July, and that many events in the sequence of farm outbreaks in 2001-2002 are consistent with higher risks in our farm connectivity matrix. Applications to other diseases, transfers between farmed and wild fish, and the effect of vaccinations are also discussed.     

Assessing the value of secondary forest for amphibians: <Emphasis Type="Italic">Eleutherodactylus</Emphasis> frogs in a gradient of forest alteration

Secondary forests constitute a growing portion of forested areas worldwide. They might have a substantial role for the conservation of biodiversity in tropical areas, but there is little information on their potential to support forest species and the recovery of faunal communities. We studied two forest frogs (Eleutherodactylus diastema and E. fitzingeri) in an area of Costa Rica composed of a mosaic of primary forest, young secondary forest and pasture, and we compared the density of calling males in areas with different forest alteration. Autoregressive models were used to compensate for potentially undesired effects of spatial autocorrelation and pseudoreplication. Both species were most abundant in riparian, primary forest. However, E. fitzingeri was also abundant in riparian secondary forests, and its density far from the river was similar in primary and secondary forest, suggesting that river proximity can influence the recovery of secondary forest for amphibians. Conversely, the density of E. diastema was similar in secondary forest and pasture, stressing interspecific differences for recovery rate. These frogs have a keystone role in nutrient cycling and food webs, and their prompt recovery might represent an important step for the functional recovery of forests. Nevertheless, the strong interspecific differences stress the complexity of these processes.     

Ulminium diluviale Unger : historique de la découverte et nouvelle étude

A fossil tree was discovered during the 16th century at Jáchymov (Bohemia). The wood was first named by Unger, in 1842, Ulminium diluviale. But it belongs to the Lauraceae family and Felix, in 1883, named it Laurinoxylon diluviale. The authors give the history and the geological setting of the area and describe the anatomy of the wood. The diagnosis of the genus Laurinoxylon Felix, 1883. is emended as follows: heteroxylous fossil wood with average sized solitary vessels or in radial groups; perforation plates simple and sometimes scalariform; intervascular pits alternate and moderately large; thyloses present. Paratracheal parenchyma. Uni to five seriate rays, slightly heterocellular and less than 1 mm high; ray-vessel pits large often stretched. Libriform or with radial pits fibres. Oil cells or mucilage (idioblasts) present. The diagnosis of the species Laurinoxylon diluviale (Unger) Felix, 1883. is also emended. Heteroxylous fossil wood with distinct growth rings; late wood poorly developed with vessels of diameter distinctly smaller as compared to the early wood and with smaller diameter fibres. Diffuse to semiporous vessels, solitary or in radial groups of two to seven , nine to 16 pores/mm²; tangential diameter 100 to 154 μm in early wood and 44 to 72 μm in late wood; vessel length 300 to 550 μm; perforation plates simple and scalariforme (6–12 bars); intervascular pits alternate, rounded (diameter 7–10 μm) or elliptic (long axes × short axes: 10–15 μm × 7–10 μm); thylosis present. Paratracheal parenchyma in more or less complete rows (1–2 cells wide) around the vessels. Heterocellular rays (1–(3) rows of upright cells), of one to five, more frequently three to four cells wide (80%); two to 36 cells high (60 to 820 μm); six to seven rays per tangential millimetre; vessels-rays pits sometimes large, stretched horizontally to vertically. Fibres of 15 to 25 μm in diameter; cell walls of 2–3 μm thick; pits not seen. Oil cells (idioblasts) at the ray margins; 27–60 μm in tangential diameter; 50–80 μm in radial diameter; 72–140 μm high; density of zero to 18 per transversal square millimetres depending on the observed area.     

Behavioral and hormonal responses of men to brief interactions with women

This study tested for behavioral and hormonal reactions of young men to brief social encounters with potential mating partners. Male college students were randomly assigned to engage in a short conversation with either a young man (male condition) or a young woman (female condition). Participants provided saliva samples before and after the conversation, completed a battery of psychological measures after the interaction, and had their behavior rated by their conversation partners. Salivary testosterone (T) increased significantly over baseline levels in the female condition only, though differences between conditions were not significant. In addition, change in T was significantly correlated with the degree to which the female confederates thought the male participants were trying to impress them. These behavioral ratings, in turn, were correlated with the participants' ratings of the female confederates as potential romantic partners. Results were generally consistent with the hypothesis that human males may exhibit a behavioral and endocrine courtship response that is similar to that observed in males of many nonhuman vertebrate species.     

Evaluation of the efficacy of various hypotensive drugs in broad-breasted white turkeys as an experimental model of arterial hypertension with high catecholamine levels

Male Broad Breasted White Turkeys (BBWT) represent an experimental model of arterial hypertension characterized by high levels of circulating and tissue catecholamines. We thought interesting to evaluate the efficacy of the long term treatment with different antihypertensive drugs. 59 male BBWT were studied, divided in five groups. The first group (13 animals) was treated with placebo; the second (14 animals) with oxprenolol 4 mg/Kg/q.d.; the third (10 animals) with labetalol 25 mg/Kg/q.d.; the fourth (11 animals) with verapamil 15 mg/Kg/ q.d.; the fifth (11 animals) with captopril 8 mg/Kg/ q.d. and furosemide 2,5 mg/Kg/q.d. All drugs were given p.o, from the 8th to the 33rd week of age. Weekly or every two weeks Blood Pressure (BP) and Heart Rate (HR) were measured by an indirect method. In all animals BP progressively increased and HR progressively decreased with age. Only the labetalol-treated animals showed a significant reduction of BP and HR through the study period as compared with the placebo-treated animals. These results confirm the preminent role played by the high levels of circulating catecholamines in determining and maintaining the arterial hypertension.