Otolith chemistry of Champsodon nudivittis (Ogilby, 1895) and Nemipterus randalli (Russell, 1986) in Iskenderun Bay,Turkey

The study objective was to investigate the chemical composition of otoliths of two Lessepsian fish migrants, namely, Champsodon nudivittis and Nemipterus randalli, which thrive in the Iskenderun Bay, Turkey. The study specifically investigated the age structure and explored differences in chemical otolith composition in relation to age. Samples were collected using a traditional Mediterranean bottom trawl (mesh size 44 mm) at depths of 45 to 90 m. A total of 78 Champsodon nudivittis (size range, 6.0 to 14.0 cm) and 60 Nemipterus randalli (size range, 6.1 to 17 cm) were captured in May 2012. Age readings were carried out (sectioning technique). Additionally, the concentrations of Na, K, Li, and Ca were determined using flame photospectrometry. The results revealed that the concentrations of Na (5.70 mg/g) and K (4.45 mg/g) in otoliths of Nemipterus randalli were predominant elements after Ca (128.71 mg/g). The concentration of Li in otoliths was also statistically different in the two species. This study contributes to the knowledge of the otolith chemistry in the two Lessepsian fish species now living in the same (but new) geographical region.     

Accounting for Population Structure in Gene-by-Environment Interactions in Genome-Wide Association Studies Using Mixed Models

Although genome-wide association studies (GWASs) have discovered numerous novel genetic variants associated with many complex traits and diseases, those genetic variants typically explain only a small fraction of phenotypic variance. Factors that account for phenotypic variance include environmental factors and gene-by-environment interactions (GEIs). Recently, several studies have conducted genome-wide gene-by-environment association analyses and demonstrated important roles of GEIs in complex traits. One of the main challenges in these association studies is to control effects of population structure that may cause spurious associations. Many studies have analyzed how population structure influences statistics of genetic variants and developed several statistical approaches to correct for population structure. However, the impact of population structure on GEI statistics in GWASs has not been extensively studied and nor have there been methods designed to correct for population structure on GEI statistics. In this paper, we show both analytically and empirically that population structure may cause spurious GEIs and use both simulation and two GWAS datasets to support our finding. We propose a statistical approach based on mixed models to account for population structure on GEI statistics. We find that our approach effectively controls population structure on statistics for GEIs as well as for genetic variants.     

Conflict between Dolphins and a Data-Scarce Fishery of the European Union

Fisheries depredation by marine mammals is an economic concern worldwide. We combined questionnaires, acoustic monitoring, and participatory experiments to investigate the occurrence of bottlenose dolphins in the fisheries of Northern Cyprus, and the extent of their conflict with set-nets, an economically important metier of Mediterranean fisheries. Dolphins were present in fishing grounds throughout the year and were detected at 28% of sets. Net damage was on average six times greater where dolphins were present, was correlated with dolphin presence, and the associated costs were considerable. An acoustic deterrent pinger was tested, but had no significant effect although more powerful pingers could have greater impact. However, our findings indicate that effective management of fish stocks is urgently required to address the overexploitation that is likely driving depredation behaviour in dolphins, that in turn leads to net damage and the associated costs to the fisheries.     

Early osteological development of the fins in the hatchery-reared red porgy, Pagrus pagrus (L. 1758)

The present study was undertaken to establish the normal, healthy features of morphological structures at various developmental stages as achieved under well-defined environmental culture conditions (temperature between 16 and 21°C, salinity 36 ppt, pH around 7.6, and oxygen saturation over 95%) common in aquaculture of the species. The pectoral fin supports began to develop at 2.90 mm total length (TL), followed by those of dorsal fins at 5.5 mm TL, caudal fins at 5.6 mm TL, pelvic fins at 5.9 mm TL and anal fins at 6.0 mm TL. The pelvic fins appeared fully at 7.4 mm TL. Development of dorsal lepidotrichia was first observed at 6.9 mm TL, attaining their final number at 7.6 mm TL. The dorsal spines first appeared at 6.5 mm TL and were complete at 7.4 mm TL. The anal lepidotrichia appeared during the development phase from 6.8 to 8.6 mm TL. At 5.6 mm TL, the upward flexion of the urostyle was initiated. The caudal lepidotrichia formed within the primordial fin at 5.6 mm TL and reached the final count at 7.4 mm TL. The caudal dermatotrichia first appeared at 7.3 mm TL and all forms were observed by 15.5 mm TL. The development pattern of fin supports found in Pagrus pagrus is quite similar to that described for other Sparid species.     

The Heavy Metal Content of Wild Edible Mushroom Samples Collected in Canakkale Province,Turkey

In this study, concentrations of heavy metals (Cd, Cr, Cu, Pb, and Zn) were determined in three edible mushroom species (Lactarius deliciosus, Russula delica, and Rhizopogon roseolus) collected in five sampling sites in Canakkale province, Turkey. Mean values of Cd, Cr, Cu, Pb, and Zn were 0.72, 0.26, 28.34, 1.53, and 64.62 mg/kg, respectively. The highest concentrations of Cd, Cu, Pb, and Zn were determined in species R. delica, while Cr was observed in L. deliciosus. In terms of the nutritional aspect, taking into account the concentration of Provisional Tolerable Weekly Intake recommended by FAO/WHO, the maximum concentration of Cd is a restrictive factor for consumption of the collected mushroom species. The concentrations of the other elements have no health risks when consumed at optimal levels.     

High-Field fMRI Reveals Brain Activation Patterns Underlying Saccade Execution in the Human Superior Colliculus

Background

The superior colliculus (SC) has been shown to play a crucial role in the initiation and coordination of eye- and head-movements. The knowledge about the function of this structure is mainly based on single-unit recordings in animals with relatively few neuroimaging studies investigating eye-movement related brain activity in humans.

Methodology/Principal Findings

The present study employed high-field (7 Tesla) functional magnetic resonance imaging (fMRI) to investigate SC responses during endogenously cued saccades in humans. In response to centrally presented instructional cues, subjects either performed saccades away from (centrifugal) or towards (centripetal) the center of straight gaze or maintained fixation at the center position. Compared to central fixation, the execution of saccades elicited hemodynamic activity within a network of cortical and subcortical areas that included the SC, lateral geniculate nucleus (LGN), occipital cortex, striatum, and the pulvinar.

Conclusions/Significance

Activity in the SC was enhanced contralateral to the direction of the saccade (i.e., greater activity in the right as compared to left SC during leftward saccades and vice versa) during both centrifugal and centripetal saccades, thereby demonstrating that the contralateral predominance for saccade execution that has been shown to exist in animals is also present in the human SC. In addition, centrifugal saccades elicited greater activity in the SC than did centripetal saccades, while also being accompanied by an enhanced deactivation within the prefrontal default-mode network. This pattern of brain activity might reflect the reduced processing effort required to move the eyes toward as compared to away from the center of straight gaze, a position that might serve as a spatial baseline in which the retinotopic and craniotopic reference frames are aligned.