Global and local visual processing in autism - a co-twin-control study.

BACKGROUND: Autism Spectrum Disorder (ASD) is associated with altered global and local visual processing. However, the nature of these alterations remains controversial, with contradictory findings and notions ranging from a reduced drive to integrate information into a coherent 'gestalt' ("weak central coherence" = WCC) to an enhanced perceptual functioning (EPF) in local processing. METHODS: This study assessed the association between autism and global/local visual processing, using a large sample of monozygotic (MZ) and dizygotic (DZ) twins (N = 290, 48% females, age = 8-31 years). The Fragmented Pictures Test (FPT) assessed global processing, whereas local processing was estimated with the Embedded Figures Test (EFT) and the Block Design Test (BDT). Autism was assessed both categorically (clinical diagnosis), and dimensionally (autistic traits). Associations between visual tasks and autism were estimated both across the cohort and within-twin pairs where all factors shared between twins are implicitly controlled. RESULTS: Clinical diagnosis and autistic traits predicted a need for more visual information for gestalt processing in the FPT across the cohort. For clinical diagnosis, this association remained within-pairs and at trend-level even within MZ twin pairs alone. ASD and higher autistic traits predicted lower EFT and BDT performance across the cohort, but these associations were lost within-pairs. CONCLUSIONS: In line with the WCC account, our findings indicate an association between autism and reduced global visual processing in children, adolescents and young adults (but no evidence for EPF). Observing a similar association within MZ twins suggests a non-shared environmental contribution.

Evolution of antigenic diversity in the tick-transmitted bacterium Borrelia afzelii: a role for host specialization?

Antigenic diversity in pathogenic microbes can be a result of at least three different processes: diversifying selection by acquired immunity, host-pathogen coevolution and/or host specialization. Here, we investigate whether host specialization drives diversity at ospC (which encodes an immunodominant surface protein) in the tick-transmitted bacterium Borrelia afzelii. We determined prevalence and infection intensity of ospC strains in naturally infected wild mammals (rodents and shrews) by 454 amplicon sequencing in combination with qPCR. Neither prevalence nor infection intensity of specific ospC strains varied in a species-specific manner (i.e. there were no significant ospC × host species interactions). Rankings of ospC prevalences were strongly positively correlated across host species. Rankings of ospC infection intensities were correlated more weakly, but only in one case significantly < 1. ospC prevalences in the studied mammals were similar to those in ticks sampled at the study site, indicating that we did not miss any mammal species that are important hosts for specific ospC strains. Based on this, we conclude that there is at best limited host specialization in B. afzelii and that other processes are likely the main drivers of ospC diversity.

Emergence of a new rhabdovirus associated with mass mortalities in eelpout (Zoarces viviparous) in the Baltic Sea.

We report the first description of a new Rhabdoviridae tentatively named eelpout rhabdovirus (EpRV genus Perhabdovirus). This virus was associated with mass mortalities in eelpout (Zoarces viviparous, Linnaeus) along the Swedish Baltic Sea coast line in 2014. Diseased fish showed signs of central nervous system infection, and brain lesions were confirmed by histology. A cytopathogenic effect was observed in cell culture, but ELISAs for the epizootic piscine viral haemorrhagic septicaemia virus (VHSV), infectious pancreas necrosis virus (IPNV), infectious haematopoietic necrosis virus (IHNV) and spring viraemia of carp virus (SVCV) were negative. Further investigations by chloroform inactivation, indirect fluorescence antibody test and electron microscopy indicated the presence of a rhabdovirus. By deep sequencing of original tissue suspension and infected cell culture supernatant, the full viral genome was assembled and we confirmed the presence of a rhabdovirus with 59.5% nucleotide similarity to the closest relative Siniperca chuatsi rhabdovirus. The full-genome sequence of this new virus, eelpout rhabdovirus (EpRV), has been deposited in GenBank under accession number KR612230. An RT-PCR based on the L-gene sequence confirmed the presence of EpRV in sick/dead eelpout, but the virus was not found in control fish. Additional investigations to characterize the pathogenicity of EpRV are planned.

Expression of perforin, granzyme A and Fas ligand mRNA in caecal tissues upon Eimeria tenella infection of naïve and immune chickens.

Cytotoxic cells of the immune system may kill infected or transformed host cells via the perforin/granzyme or the Fas ligand (FasL) pathways. The purpose of this study was to determine mRNA expression of perforin, granzyme A and FasL in Eimeria tenella-infected tissues at primary infection and infection of immune chickens as an indirect measure of cytotoxic cell activity. Chickens were rendered immune by repeated E. tenella infections, which were manifested as an absence of clinical signs or pathological lesions and significantly reduced oocyst production upon challenge infection. During primary E. tenella infection, perforin, granzyme A and FasL mRNA expression in caecal tissue was significantly increased at 10 days after infection, compared to uninfected birds. In contrast, at infection of immune birds, perforin and granzyme A mRNA expression in caecal tissue was significantly increased during the early stages of E. tenella challenge infection, days 1-4, which coincided with a substantial reduction of parasite replication in these birds. These results indicate the activation of cytotoxic pathways in immune birds and support a role for cytotoxic T cells in the protection against Eimeria infections.

Resistance training improves fatigue and quality of life in previously sedentary breast cancer survivors: a randomised controlled trial.

The primary aim of this study was to evaluate the benefits of resistance training (RT) on quality of life (QOL) and fatigue in breast cancer survivors as an adjunct to usual care. We recruited 39 women who had survived breast cancer [mean age (y) 51.9 ± 8.8; time since diagnosis (m) 11.6 ± 13.2]. Primary outcomes were fatigue as assessed by the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT) scale and QOL as assessed by the Functional Assessment of Cancer Therapy - General (FACT-G) scale. ANCOVA was used to assess the change in the primary outcomes while controlling for baseline values, with effect sizes (ES) displayed as partial Eta squared. The experimental group received supervised RT 3 days per week in a university clinic for 16 weeks. Perceptions of fatigue improved significantly in the RT group compared to controls [mean (SD) 6.7 (7.5) points vs. 1.5 (3.7) points], (P = 0.006, ES = 0.20) as did QOL [6.9 (8.5) points vs. 1.6 (4.4) points], (P = 0.015, ES = 0.16). We demonstrated both statistically and clinically important improvements in fatigue and QOL in response to RT in breast cancer survivors.

The native bacterioplankton community in the central baltic sea is influenced by freshwater bacterial species.

The Baltic Sea is one of the largest brackish environments on Earth. Despite extensive knowledge about food web interactions and pelagic ecosystem functioning, information about the bacterial community composition in the Baltic Sea is scarce. We hypothesized that due to the eutrophic low-salinity environment and the long water residence time (>5 years), the bacterioplankton community from the Baltic proper shows a native "brackish" composition influenced by both freshwater and marine phylotypes. The bacterial community composition in surface water (3-m depth) was examined at a single station throughout a full year. Denaturing gradient gel electrophoresis (DGGE) showed that the community composition changed over the year. Further, it indicated that at the four extensive samplings (16S rRNA gene clone libraries and bacterial isolates from low- and high-nutrient agar plates and seawater cultures), different bacterial assemblages associated with different environmental conditions were present. Overall, the sequencing of 26 DGGE bands, 160 clones, 209 plate isolates, and 9 dilution culture isolates showed that the bacterial assemblage in surface waters of the central Baltic Sea was dominated by Bacteroidetes but exhibited a pronounced influence of typical freshwater phylogenetic groups within Actinobacteria, Verrucomicrobia, and Betaproteobacteria and a lack of typical marine taxa. This first comprehensive analysis of bacterial community composition in the central Baltic Sea points to the existence of an autochthonous estuarine community uniquely adapted to the environmental conditions prevailing in this brackish environment.

Global patterns of diversity and community structure in marine bacterioplankton.

Because of their small size, great abundance and easy dispersal, it is often assumed that marine planktonic microorganisms have a ubiquitous distribution that prevents any structured assembly into local communities. To challenge this view, marine bacterioplankton communities from coastal waters at nine locations distributed world-wide were examined through the use of comprehensive clone libraries of 16S ribosomal RNA genes, used as operational taxonomic units (OTU). Our survey and analyses show that there were marked differences in the composition and richness of OTUs between locations. Remarkably, the global marine bacterioplankton community showed a high degree of endemism, and conversely included few cosmopolitan OTUs. Our data were consistent with a latitudinal gradient of OTU richness. We observed a positive relationship between the relative OTU abundances and their range of occupation, i.e. cosmopolitans had the largest population sizes. Although OTU richness differed among locations, the distributions of the major taxonomic groups represented in the communities were analogous, and all local communities were similarly structured and dominated by a few OTUs showing variable taxonomic affiliations. The observed patterns of OTU richness indicate that similar evolutionary and ecological processes structured the communities. We conclude that marine bacterioplankton share many of the biogeographical and macroecological features of macroscopic organisms. The general processes behind those patterns are likely to be comparable across taxa and major global biomes.

Effects of Bacteriophages on the Population Dynamics of Four Strains of Pelagic Marine Bacteria.

Viral lysis of specific bacterial populations has been suggested to be an important factor for structuring marine bacterioplankton communities. In the present study, the influence of bacteriophages on the diversity and population dynamics of four marine bacterial phage-host systems was studied experimentally in continuous cultures and theoretically by a mathematical model. By use of whole genome DNA hybridization toward community DNA, we analyzed the dynamics of individual bacterial host populations in response to the addition of their specific phage in continuous cultures of mixed bacterial assemblages. In these experiments, viral lysis had only temporary effects on the dynamics and diversity of the individual bacterial host species. Following the initial lysis of sensitive host cells, growth of phage-resistant clones of the added bacteria resulted in a distribution of bacterial strains in the phage-enriched culture that was similar to that in the control culture without phages after about 50-60 h incubation. Consequently, after a time frame of 5-10 generations after lysis, it was the interspecies competition rather than viral lysis of specific bacterial strains that was the driving force in the regulation of bacterial species composition in these experiments. The clonal diversity, on the other hand, was strongly influenced by viral activity, since the clonal composition of the four species in the phage-enriched culture changed completely from phage-sensitive to phage-resistant clones. The model simulation predicted that viral lysis had a strong impact on the population dynamics, the species composition, and the clonal composition of the bacterial community over longer time scales (weeks). However, according to the model, the overall density of bacteria in the system was not affected by phages, since resistant clones complemented the fluctuations caused by viral lysis. Based on the model analysis, we therefore suggest that viral lysis can have a strong influence on the dynamics of bacterial populations in planktonic marine systems.

Problems with the DSM-IV diagnosis of pedophilia.

This paper examines the taxonomic adequacy of the Diagnostic and Statistical Manual, 4th ed., DSM-IV (American Psychiatric Association, 1994) diagnostic category of pedophilia. This diagnosis, as well as the other sexual disorders, have been ignored in DSM field trials. There is no empirical information about the reliability or validity of this diagnosis. Moreover, because the vagueness of the diagnostic criteria, clinicians would need to make inferences that would likely lead to reliability problems in diagnosis. Further, the DSM diagnostic criteria include constructs that are not intersubjectively verifiable and for which there are no valid measures. This can also lead to lack of diagnostic reliability and accuracy. Most problematical however, there are aspects of the diagnostic criteria, most notably the presence of an "ego dystonic sexual attraction to children," that are incorrect exclusion criteria. Suggestions for improvement are provided.

Significance of size and nucleic acid content heterogeneity as measured by flow cytometry in natural planktonic bacteria.

Total bacterial abundances estimated with different epifluorescence microscopy methods (4',6-diamidino-2-phenylindole [DAPI], SYBR Green, and Live/Dead) and with flow cytometry (Syto13) showed good correspondence throughout two microcosm experiments with coastal Mediterranean water. In the Syto13-stained samples we could differentiate bacteria with apparent high DNA (HDNA) content and bacteria with apparent low DNA (LDNA) content. HDNA bacteria, "live" bacteria (determined as such with the Molecular Probes Live/Dead BacLight bacterial viability kit), and nucleoid-containing bacteria (NuCC) comprised similar fractions of the total bacterial community. Similarly, LDNA bacteria and "dead" bacteria (determined with the kit) comprised a similar fraction of the total bacterial community in one of the experiments. The rates of change of each type of bacteria during the microcosm experiments were also positively correlated between methods. In various experiments where predator pressure on bacteria had been reduced, we detected growth of the HDNA bacteria without concomitant growth of the LDNA bacteria, such that the percentage contribution of HDNA bacteria to total bacterial numbers (%HDNA) increased. This indicates that the HDNA bacteria are the dynamic members of the bacterial assemblage. Given how quickly and easily the numbers of HDNA and LDNA bacteria can be obtained, and given the similarity to the numbers of "live" cells and NuCC, the %HDNA is suggested as a reference value for the percentage of actively growing bacteria in marine planktonic environments.

A PCR based method for the identification of equine influenza virus from clinical samples.

In this paper we describe the development of a nested RT-PCR assay for the rapid diagnosis and characterisation of influenza virus directly from clinical specimens. Viral RNA is extracted from nasal swabs by the guanidine thiocyanate extraction method, and subsequently reverse transcribed. The complementary DNA is then used as template in a nested PCR reaction. Primers designed for use in this assay are specific for three templates; (1) the nucleoprotein (NP) gene, (2) the haemagglutinin gene of the H7N7 equine influenza virus (A1), and (3) the haemagglutinin gene of the H3N8 equine influenza virus (A2). We show that the assays are specific for the target genes chosen, and display sensitivity similar to virus isolation. The NP assay detects a variety of different influenza subtypes, whereas A1 and A2 assays are specific for influenza subtypes H7N7 and H3N8, respectively. Sequencing of amplicons obtained in the A2 assay yields information on antigenic regions of the haemagglutinin molecule, and use of this procedure in the routine surveillance of equine influenza will enable tentative characterisation of circulating viruses despite difficulties in isolating field strains of the H3N8 subtype. The A1 assay will be useful in ascertaining whether viruses of the H7N7 subtype still circulate amongst horses, or whether these are extinct.

Rapid determination of bacterial abundance, biovolume, morphology, and growth by neural network-based image analysis

Annual bacterial plankton dynamics at several depths and locations in the Baltic Sea were studied by image analysis. Individual bacteria were classified by using an artificial neural network which also effectively identified nonbacterial objects. Cell counts and frequencies of dividing cells were determined, and the data obtained agreed well with visual observations and previously published values. Cell volumes were measured accurately by comparison with bead standards. The survey included 690 images from a total of 138 samples. Each image contained approximately 200 bacteria. The images were analyzed automatically at a rate of 100 images per h. Bacterial abundance exhibited coherent patterns with time and depth, and there were distinct subsurface peaks in the summer months. Four distinct morphological classes were resolved by the image analyzer, and the dynamics of each could be visualized. The bacterial growth rates estimated from frequencies of dividing cells were different from the bacterial growth rates estimated by the thymidine incorporation method. With minor modifications, the image analysis technique described here can be used to analyze other planktonic classes.

Dominant marine bacterioplankton species found among colony-forming bacteria.

The density of specific aquatic bacteria was determined by use of whole-genome DNA hybridization towards community DNA. From a coastal marine environment (northern Baltic Sea), 48 specific bacteria were isolated on solid media over a 1-year period. Based on the presented hybridization protocol, the total density of the isolates ranged between 7 and 69% of the bacteria determined by acridine orange direct counts. When compared to the number of nucleoid-containing cells, the range increased to 29 to 111%. Thus, our results showed that bacteria able to form colonies on solid media accounted for a large fraction of the bacterioplankton. There were significant changes in the density of the different bacteria over the year, suggesting that bacterioplankton exhibit a seasonal succession analogous to phytoplankton. The bacteria studied were of diverse phylogenetic origin, being distributed among the alpha, beta, and gamma subdivisions of the class Proteobacteria and the cytophaga-flexibacter group. Partial 16S rRNA gene sequence analysis of 29 Baltic Sea isolates as well as of 30 Southern California Bight isolates showed that a majority of the isolates had low similarity (0.85 to 0.95) to reported sequence data. This indicated that the diversity of marine bacteria able to grow on solid media is largely unexplored.

Developing a European professional record of achievement in engineering: towards portable qualifications.

This paper describes a Leonardo da Vinci pilot project the aim of which is to establish a Professional Record of Achievement within the engineering industry for developing and recording career development plans and the resulting requirements for learning and for personal and professional development. recording learning achievements and professional development, and the accumulation of credit towards relevant qualifications. The project will draw upon recent experiences and developments in different countries. A survey of some previous work in the area of portfolios or records of achievement in Europe is presented.

Total counts of marine bacteria include a large fraction of non-nucleoid-containing bacteria (ghosts).

Counts of heterotrophic bacteria in marine waters are usually in the order of 5 x 10(sup5) to 3 x 10(sup6) bacteria ml(sup-1). These numbers are derived from unspecific fluorescent staining techniques (J. E. Hobbie, R. J. Daley, and S. Jasper, Appl. Environ. Microbiol. 33:1225-1228, 1977; K. G. Porter and Y. S. Feig, Limnol. Oceanogr. 25:943-948, 1980) and are subsequently defined as total counts of bacteria. In samples from the Baltic Sea, the North Sea (Skagerrak), and the northeastern Mediterranean Sea, we found that only a minor fraction (2 to 32%) of total counts can be scored as bacteria with nucleoids. Lack of DNA no doubt means inactive cells; therefore, a much lower number of bacteria that grow at rates higher than those previously estimated must be responsible for the measured bacterial production in these seas. The remaining bacterium-sized and/or -shaped particles included in total counts may be cell residues of virus-lysed bacteria (ghosts) or remains of protozoan grazing.

Bacteria-organic matter coupling and its significance for oceanic carbon cycling.

This paper synthesizes current ideas on the role of the microbial loop in carbon fluxes in the ocean and proposes some directions for future research. Organic matter flux into bacteria is highly variable, which can significantly influence the pathways of carbon flow in the ocean. A goal for future research is to elucidate the mechanistic bases of bacteria-organic matter coupling. This research should take into consideration the micrometer-scale distribution of bacteria and the composition, structure, and dynamics of the organic matter field in the bacterium's microhabitat. The ideas on the interactions of bacteria with the particulate organic phase need to be revised in view of recent findings of highly abundant, previously unknown particles ranging in size from nanometers to hundreds of micrometers. The "hot-spots" in the distribution of organic matter and remineralized nutrients can influence the rates as well as the direction of biogeochemical fluxes. Slow-to-degrade dissolved organic matter (DOM) may be produced because of loose bacteria-organic matter coupling resulting in DOM storage. Its use at a later time and place has profound implications for carbon fluxes and food web dynamics. A fundamental research need for the future is to understand the ecological interactions among the members of the microbial loop in an appropriate microhabitat context. While this goal was previously intractable, new molecular and optical techniques should make it possible to understand the biogeochemical activities of the microbial loop in terms of the ecology and evolution of pelagic microbial communities.

Conservation of regulatory and structural genes for a multi-component phenol hydroxylase within phenol-catabolizing bacteria that utilize a meta-cleavage pathway.

Pseudomonas sp. strain CF600 can degrade phenol and some of its methylated derivatives via a plasmid (pVI150)-encoded pathway. The metabolic route involves hydroxylation by a multi-component phenol hydroxylase and a subsequent meta-cleavage pathway. All 15 structural genes involved are clustered in an operon that is regulated by a divergently transcribed transcriptional activator. The multi-component nature of the phenol hydroxylase is unusual since reactions of this type are usually accomplished by single component flavoproteins. We have isolated and analysed a number of marine bacterial isolates capable of degrading phenol and a range of other aromatic compounds as sole carbon and energy sources. Southern hybridization and enzyme assays were used to compare the catabolic pathways of these strains and of the archetypal phenol-degrader Pseudomonas U, with respect to known catabolic genes encoded by Pseudomonas CF600. All the strains tested that degraded phenol via a meta-cleavage pathway were found to have DNA highly homologous to each of the components of the multicomponent phenol hydroxylase. Moreover, DNA of the same strains also strongly hybridized to probes specific for pVI150-encoded meta-pathway genes and the specific regulator of its catabolic operon. These results demonstrate conservation of structural and regulatory genes involved in aromatic catabolism within strains isolated from diverse geographical locations (UK, Norway and USA) and a range of habitats that include activated sludge, sea water and fresh-water mud.

Release of bacterial DNA by marine nanoflagellates, an intermediate step in phosphorus regeneration.

The concentrations of dissolved DNA and nanoflagellates were found to covary during a study of diel dynamics of the microbial food web in the Adriatic Sea. This observation was further investigated in a continuous seawater culture when nanoflagellates were fed bacteria grown in filtered seawater. Analysis of dissolved organic phosphorus and dissolved DNA showed a sixfold increase of dissolved DNA in the presence of the nanoflagellates (Ochromonas sp.). The amount of DNA released suggested that the majority of the consumed bacterial DNA was ejected. Phagotrophic nanoflagellates thus represent an important source of origin for dissolved DNA. The rate of breakdown of dissolved DNA and release of inorganic phosphorus in the pelagic ecosystem is suggested to be dependent on the ambient phosphate pool. In the P-limited northern Adriatic Sea, rapid degradation of the labelled DNA could be demonstrated, whereas the N-limited southern California bight water showed a much lower rate. Phosphorus originating from dissolved DNA was shown to be transferred mainly to organisms in the <3-mum-size fractions. On the basis of the C/P ratios, we suggest that a significant fraction of the phosphorus demand by the autotrophs may be sustained by the released DNA during stratified conditions. Thus, the nucleic acid-rich bacterial biomass grazed by protozoa plays an important role in the biogeochemical cycling of phosphorus in the marine environment.

Identification of Vibrio anguillarum in fish by using partial 16S rRNA sequences and a specific 16S rRNA oligonucleotide probe.

16S rRNA from seven different Vibrio anguillarum strains was partially sequenced and compared. From this sequence information we could design a 25-base-long oligonucleotide and use it as a specific probe for identification of V. anguillarum. This was determined by RNA-DNA colony hybridization and slot-blot hybridization. Strong, specific hybridization to the probe was observed for all V. anguillarum strains tested. Furthermore, no cross-hybridization could be seen against five other bacterial species. The detection limit was 5 x 10(3) bacteria per ml. It was even possible to detect V. anguillarum, by slot-blot hybridization, directly in a homogenized kidney from a fish that had died of vibriosis. The partial sequence information revealed small but significant differences between strains of the same species. These sequence differences are sufficiently significant to allow serotyping on the RNA level. Comparing strains of different serotypes revealed a 10-base and an 11-base difference in V. anguillarum serotypes O8 and O9, respectively, in a 122-base partial sequence.

Protection of rainbow trout against vibriosis and furunculosis by the use of attenuated strains of Vibrio anguillarum.

The fish pathogen Vibrio anguillarum causes a lethal infection in rainbow trout (Salmo gairdneri). Three different avirulent mutants, constructed by transposon insertion mutagenesis (VAN20 and VAN70) or as antibiotic-resistant mutants (VAN1000), were isolated by screening 200 individual isolated mutants for avirulence. When used as live vaccines, all three avirulent mutants were able to induce protective immunity against the homologous as well as a heterologous strain of V. anguillarum. When VAN1000 was used, protective immunity could be recorded 1 week after bath vaccination with 10(7) bacteria per ml of water for 30 min. A single-dose immunization was effective for at least 12 weeks. Western immunoblotting showed that strains of V. anguillarum have antigenic determinants in common with Aeromonas strains. Therefore, we tested and confirmed that VAN1000 also was able to induce protective immunity against challenge with Aeromonas salmonicida.