Converting Endangered Species Categories to Probabilities of Extinction for Phylogenetic Conservation Prioritization

Categories of imperilment like the global IUCN Red List have been transformed to probabilities of extinction and used to rank species by the amount of imperiled evolutionary history they represent (e.g. by the Edge of Existence programme). We investigate the stability of such lists when ranks are converted to probabilities of extinction under different scenarios.Using a simple example and computer simulation, we show that preserving the categories when converting such list designations to probabilities of extinction does not guarantee the stability of the resulting lists.Care must be taken when choosing a suitable transformation, especially if conservation dollars are allocated to species in a ranked fashion. We advocate routine sensitivity analyses

Adverse biochemical and physiological effects of prostacyclin in experimental brain oedema

Background: Prostacyclin (PGI(2)) and its stable analogues are known to reduce capillary hydraulic permeability. This study explores the biochemical and physiological effects of i.v. infusion of low-dose PGI(2) in an experimental model of vasogenic brain oedema. Methods: Twenty-seven anaesthetized and mechanically ventilated piglets with brain oedema induced by intrathecal injection of lipopolysaccharide (LPS) were used. Five of the animals received a continuous infusion of PGI(2) (1 ng kg(-1) min(-1)) i.v. Four microdialysis catheters were placed in the brain to measure interstitial concentrations of glucose, lactate, and glycerol. Mean arterial pressure (MAP), intracranial pressure (ICP) and temperature were monitored continuously. Low-dose infusion of PGI(2) started 1 h before the LPS injection and was constant during the study period. Results: Intracranial pressure increased significantly in animals treated with PGI(2). The increase in ICP was associated with significant cerebral biochemical changes: decrease in glucose, increase in lactate, increase in lactate/glucose ratio and increase in glycerol. Conclusion: In LPS-induced brain oedema i.v. infusion of low-dose PGI(2) caused a further increase in ICP and a perturbation of energy metabolism, indicating cerebral ischemia and degradation of cellular membranes

Do instream habitat variables and the abundance of brown trout Salmo trutta (L.) affect the distribution and growth of stone loach, Barbatula barbatula (L.)?

Along a stream, we investigated whether the abundance of stone loach (Barbatula barbatula, L.) was related to the presence of brown trout (Salmo trutta, L.) and instream habitat variables. First, a field survey was carried out where different habitat variables and the densities of both species were quantified and subjected to principal components analysis. Then the abundance of stone loach was related to the scores of the retained axes (eigenvalues >1). The abundance of stone loach was positively correlated to substrate particle size, amount of shade, temperature, discharge and current velocity, but negatively correlated to brown trout abundance. Secondly, a month-long field enclosure experiment in a stream was performed to test for any negative effects of brown trout on stone loach growth. Four treatments were used: intraspecific competition (stone loach at double density), interspecific competition (stone loach + small trout), predation (stone loach + large trout) and a control (stone loach alone). The results showed that large trout tended to have negative effects on final stone loach biomass. The absence of a negative effect of large trout on resource density suggests that nonlethal effects rather than resource competition caused this trend

Identification of molecular markers for DNA barcoding in the Aphidiinae (Hym. Braconidae)

Correspondence: Stephane Derocles, Fax: +33 2 23 48 51 70; E-mail: [email protected] audienceReliable identification of Aphidiinae species (Braconidae) is a prerequisite for conducting studies on aphidparasitoid interactions at the community level. However, morphological identification of Aphidiinae species remains problematic even for specialists and is almost impossible with larval stages. Here, we compared the efficiency of two molecular markers [mitochondrial cytochrome c oxydase I (COI) and nuclear long wavelength rhodopsin (LWRh)] that could be used to accurately identify about 50 species of Aphidiinae that commonly occur in aphidparasitoid networks in northwestern Europe. We first identified species on a morphological basis and then assessed the consistency of genetic and morphological data. Probably because of mitochondrial introgression, Aphidius ervi and A.microlophii were indistinguishable on the basis of their COI sequences, whereas LWRh sequences discriminated these species. Conversely, because of its lower variability, LWRh failed to discriminate two pairs of species (Aphidius aquilus, Aphidius salicis, Lysiphlebus confusus and Lysiphlebus fabarum). Our study showed that no unique locus but a combination of two genes should be used to accurately identify members of Aphidiinae