Spatio-temporal population structuring and genetic diversity retention in depleted Atlantic bluefin tuna of the Mediterranean Sea.

Fishery genetics have greatly changed our understanding of population dynamics and structuring in marine fish. In this study, we show that the Atlantic Bluefin tuna (ABFT, Thunnus thynnus), an oceanic predatory species exhibiting highly migratory behavior, large population size, and high potential for dispersal during early life stages, displays significant genetic differences over space and time, both at the fine and large scales of variation. We compared microsatellite variation of contemporary (n = 256) and historical (n = 99) biological samples of ABFTs of the central-western Mediterranean Sea, the latter dating back to the early 20th century. Measures of genetic differentiation and a general heterozygote deficit suggest that differences exist among population samples, both now and 96-80 years ago. Thus, ABFTs do not represent a single panmictic population in the Mediterranean Sea. Statistics designed to infer changes in population size, both from current and past genetic variation, suggest that some Mediterranean ABFT populations, although still not severely reduced in their genetic potential, might have suffered from demographic declines. The short-term estimates of effective population size are straddled on the minimum threshold (effective population size = 500) indicated to maintain genetic diversity and evolutionary potential across several generations in natural populations.

Generalized anxiety disorder: is there any specific symptom?

OBJECTIVE: The main aim of the present research was to evaluate the coherence of generalized anxiety disorder (GAD) psychopathological pattern, the robustness of its diagnostic criteria, and the clinical utility of considering this disorder as a discrete condition rather than assigning it a dimensional value. METHOD: The study was designed in a purely naturalistic setting and carried out using a community sample; data from the Sesto Fiorentino Study were reanalyzed. RESULTS: Of the 105 subjects who satisfied the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for the diagnosis of GAD, only 18 (17.1%) had no other comorbid DSM-IV disorder. The most frequent comorbid condition was major depressive disorder (70.4 %). Only 2 of the GAD diagnostic symptoms (excessive worry and muscle tension) showed a specific association with the diagnosis itself, whereas the others, such as feeling wound up, tense, or restless, concentration problems, and fatigue, were found to be more prevalent in major depressive disorder than in GAD. CONCLUSION: Our study demonstrates that GAD, as defined by DSM-IV criteria, shows a substantial overlap with other DSM-IV diagnoses (especially with mood disorders) in the general population. Furthermore, GAD symptoms are frequent in all other disorders included in the mood/anxiety spectrum. Finally, none of the GAD symptoms, apart from muscle tension, distinguished GAD from patients without GAD.

Are Psychiatric Diagnoses an Obstacle for Research and Practice? Reliability, Validity and the Problem of Psychiatric Diagnoses. The Case of GAD.

The present article focused on the problem of validity, reliability and specificity of psychiatric diagnoses.The authors moved by the concept of syndrome, defined by Sydenham in the 18th century as a constellation of several interrelated symptoms, showing a stable, characteristic structure and a peculiar prognosis, in order to analyse the peculiarity of the current psychiatric nosology. In our opinion, the current nosographic system based on DSM-IV criteria, prevents psychiatry from benefiting of the significant technological progress that has led the rest of medical sciences to important clinical achievements in the last 20 years. The case of Generalized Anxiety Disorder was taken as an example of a disease characterized by unstable diagnostic criteria, high rate of comorbidity and uncertain boundaries. An analysis of the data from the Sesto Fiorentino study was performed to investigate the presence of common mood and anxiety symptoms across the most represented DSM IV diagnoses, in order to evaluate the specificity of these symptoms.The results supported the hypothesis of a low specificity of these symptoms, suggesting the need for psychiatry to find new and more specific markers and instruments.

DNA barcoding for species assignment: the case of Mediterranean marine fishes.

BACKGROUND: DNA barcoding enhances the prospects for species-level identifications globally using a standardized and authenticated DNA-based approach. Reference libraries comprising validated DNA barcodes (COI) constitute robust datasets for testing query sequences, providing considerable utility to identify marine fish and other organisms. Here we test the feasibility of using DNA barcoding to assign species to tissue samples from fish collected in the central Mediterranean Sea, a major contributor to the European marine ichthyofaunal diversity. METHODOLOGY/PRINCIPAL FINDINGS: A dataset of 1278 DNA barcodes, representing 218 marine fish species, was used to test the utility of DNA barcodes to assign species from query sequences. We tested query sequences against 1) a reference library of ranked DNA barcodes from the neighbouring North East Atlantic, and 2) the public databases BOLD and GenBank. In the first case, a reference library comprising DNA barcodes with reliability grades for 146 fish species was used as diagnostic dataset to screen 486 query DNA sequences from fish specimens collected in the central basin of the Mediterranean Sea. Of all query sequences suitable for comparisons 98% were unambiguously confirmed through complete match with reference DNA barcodes. In the second case, it was possible to assign species to 83% (BOLD-IDS) and 72% (GenBank) of the sequences from the Mediterranean. Relatively high intraspecific genetic distances were found in 7 species (2.2%-18.74%), most of them of high commercial relevance, suggesting possible cryptic species. CONCLUSION/SIGNIFICANCE: We emphasize the discriminatory power of COI barcodes and their application to cases requiring species level resolution starting from query sequences. Results highlight the value of public reference libraries of reliability grade-annotated DNA barcodes, to identify species from different geographical origins. The ability to assign species with high precision from DNA samples of disparate quality and origin has major utility in several fields, from fisheries and conservation programs to control of fish products authenticity.

A reliable DNA barcode reference library for the identification of the North European shelf fish fauna.

Valid fish species identification is an essential step both for fundamental science and fisheries management. The traditional identification is mainly based on external morphological diagnostic characters, leading to inconsistent results in many cases. Here, we provide a sequence reference library based on mitochondrial cytochrome c oxidase subunit I (COI) for a valid identification of 93 North Atlantic fish species originating from the North Sea and adjacent waters, including many commercially exploited species. Neighbour-joining analysis based on K2P genetic distances formed nonoverlapping clusters for all species with a ≥99% bootstrap support each. Identification was successful for 100% of the species as the minimum genetic distance to the nearest neighbour always exceeded the maximum intraspecific distance. A barcoding gap was apparent for the whole data set. Within-species distances ranged from 0 to 2.35%, while interspecific distances varied between 3.15 and 28.09%. Distances between congeners were on average 51-fold higher than those within species. The validation of the sequence library by applying BOLDs barcode index number (BIN) analysis tool and a ranking system demonstrated high taxonomic reliability of the DNA barcodes for 85% of the investigated fish species. Thus, the sequence library presented here can be confidently used as a benchmark for identification of at least two-thirds of the typical fish species recorded for the North Sea.

Genetic structure of bluefin tuna in the mediterranean sea correlates with environmental variables.

BACKGROUND: Atlantic Bluefin Tuna (ABFT) shows complex demography and ecological variation in the Mediterranean Sea. Genetic surveys have detected significant, although weak, signals of population structuring; catch series analyses and tagging programs identified complex ABFT spatial dynamics and migration patterns. Here, we tested the hypothesis that the genetic structure of the ABFT in the Mediterranean is correlated with mean surface temperature and salinity. METHODOLOGY: We used six samples collected from Western and Central Mediterranean integrated with a new sample collected from the recently identified easternmost reproductive area of Levantine Sea. To assess population structure in the Mediterranean we used a multidisciplinary framework combining classical population genetics, spatial and Bayesian clustering methods and a multivariate approach based on factor analysis. CONCLUSIONS: FST analysis and Bayesian clustering methods detected several subpopulations in the Mediterranean, a result also supported by multivariate analyses. In addition, we identified significant correlations of genetic diversity with mean salinity and surface temperature values revealing that ABFT is genetically structured along two environmental gradients. These results suggest that a preference for some spawning habitat conditions could contribute to shape ABFT genetic structuring in the Mediterranean. However, further studies should be performed to assess to what extent ABFT spawning behaviour in the Mediterranean Sea can be affected by environmental variation.

A ranking system for reference libraries of DNA barcodes: application to marine fish species from Portugal.

BACKGROUND: The increasing availability of reference libraries of DNA barcodes (RLDB) offers the opportunity to the screen the level of consistency in DNA barcode data among libraries, in order to detect possible disagreements generated from taxonomic uncertainty or operational shortcomings. We propose a ranking system to attribute a confidence level to species identifications associated with DNA barcode records from a RLDB. Here we apply the proposed ranking system to a newly generated RLDB for marine fish of Portugal. METHODOLOGY/PRINCIPAL FINDINGS: Specimens (n = 659) representing 102 marine fish species were collected along the continental shelf of Portugal, morphologically identified and archived in a museum collection. Samples were sequenced at the barcode region of the cytochrome oxidase subunit I gene (COI-5P). Resultant DNA barcodes had average intra-specific and inter-specific Kimura-2-parameter distances (0.32% and 8.84%, respectively) within the range usually observed for marine fishes. All specimens were ranked in five different levels (A-E), according to the reliability of the match between their species identification and the respective diagnostic DNA barcodes. Grades A to E were attributed upon submission of individual specimen sequences to BOLD-IDS and inspection of the clustering pattern in the NJ tree generated. Overall, our study resulted in 73.5% of unambiguous species IDs (grade A), 7.8% taxonomically congruent barcode clusters within our dataset, but awaiting external confirmation (grade B), and 18.7% of species identifications with lower levels of reliability (grades C/E). CONCLUSION/SIGNIFICANCE: We highlight the importance of implementing a system to rank barcode records in RLDB, in order to flag taxa in need of taxonomic revision, or reduce ambiguities of discordant data. With increasing DNA barcode records publicly available, this cross-validation system would provide a metric of relative accuracy of barcodes, while enabling the continuous revision and annotation required in taxonomic work.

Identifying Fishes through DNA Barcodes and Microarrays.

BACKGROUND: International fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection. METHODOLOGY/PRINCIPAL FINDINGS: This study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S), cytochrome b (cyt b), and cytochrome oxidase subunit I (COI) for the identification of 50 European marine fish species by combining techniques of "DNA barcoding" and microarrays. In a DNA barcoding approach, neighbour Joining (NJ) phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the "position of label" effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (>90%) renders the DNA barcoding marker as rather unsuitable for this high-throughput technology. CONCLUSIONS/SIGNIFICANCE: Based on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products.

Postural improvement using core integration to lengthen myofascia.

Postural organization is controlled by the central nervous system in conjunction with the skeletal, muscular, and fascial systems. This paper explores the effects on static and dynamic postural misalignment of a neuromotor re-education intervention. In total, 13 control and 14 experimental subjects with postural deviations were studied. An individualized Dellagrotte core-integration intervention was performed with subjects in the experimental group over a period of 2 months. Twenty-five postural parameters were assessed pre- and post-intervention to give a global postural assessment score. There was significant improvement in the global postural score for the experimental group compared to the control group. Six core pathways are described along with the theoretical background from which they were developed.