Isolation and characterisation of 16 microsatellite markers for the endangered Gould’s long-eared bat (Nyctophilus gouldi) and cross-amplification in the lesser long-eared bat (N. geoffroyi)

Sixteen microsatellite markers were developed for use on two species of long-eared bats (Nyctophilus). 454 pyrosequencing of genomic DNA was conducted on N. gouldi which is listed as endangered in South Australia. Fifteen loci successfully amplified on N. gouldi while nine cross-amplified for use on N. geoffroyi. Two populations from south-eastern Australia were genotyped for each species, comprising 91 individuals for N. gouldi and 70 individuals for N. geoffroyi. There was no evidence of linkage disequilibrium and all loci displayed Hardy–Weinberg equilibrium except Nyg19 and Nyg39 which displayed evidence of null alleles in both N. geoffroyi populations. These markers will prove valuable in assessing connectivity between endangered populations of N. gouldi, and facilitate a comparative investigation into the impacts of habitat fragmentation on two vespertilionids.     

Discrete nanoparticles induce loss of Legionella pneumophila biofilms from surfaces

Nanoparticles (NPs) have been shown to induce dispersal events in microbial biofilms but the mechanism of the dispersal is unknown. Biofilms contaminate many man-made aquatic systems such as cooling towers, spas and dental lines. Within these biofilms, Legionella pneumophila is a primary pathogen, leading to these environments serving as sources for disease outbreaks. Here we show a reduction in biofilm bio-volume upon treatment with citrate-coated 6-nm platinum NPs, polyethylene glycol (PEG)-coated 11-nm gold NPs, and PEG-coated 8-nm iron oxide NPs. Treatment with citrate-coated 8-nm silver NPs, however, did not reduce biomass. The synthesis of NPs that remain dispersed and resist irreversible aggregation in the exposure media appears to be a key factor in the ability of NPs to induce biofilm dispersal.     

Effects of stimulus structure and target-distracter similarity on the development of visual memory representations in schizophrenia

Introduction. In a previous study (Silverstein, Bakshi, Chapman, & Nowlis, 1998a, Cognitive Neuropsychiatry) we demonstrated that while schizophrenia patients showed similar learning curves as nonpatient controls when determining whether a configural pattern of elements has been seen before or not, they did not demonstrate any learning curve with nonconfigural stimuli (in contrast to controls). Methodological limitations of that study, however, precluded generalisability of those effects.Methods. In the present study, therefore, different groups of schizophrenia patients (n = 18) and controls (n = 22) were administered a modified version of the familiarity judgement task used in Silverstein et al. (1998a). In the new version of the task: (1) the patterns that repeated were different for each participant; and (2) half of the nonrepeating patterns were configural and half were nonconfigural.Results. These indicated stronger perceptual learning effects for the configural compared to the nonconfigural patterns, and overall better performance and more pronounced learning effects for the control group.Conclusions. The data provide further evidence for a schizophrenia-related impairment in perceptual organisation and in the ability to develop memory representations for novel stimuli.