Approach to the identification of sex-determining genes in the tilapia genome by genetic mapping and comparative positional cloning

Tilapia (Oreochromis species) are one of the most dominant species in the aquaculture market. Genomic approaches may contribute to tilapia culture in the near future by identifying genes controlling traits valuable at the market. One of the most important traits for farming of tilapia is sex because monosex culture shows the best efficiency of culture. In tilapia, however, the mechanisms of sex-determination have been poorly understood because of the variation in the genetic basis of sex-determination and the lack of morphological differences between sex chromosomes. To facilitate QTL analysis of these traits, a genetic linkage map was constructed from hybrids between Oreochromis aureus and O. niloticus using CRIMAP. The linkage map consists of 25 linkage groups with about 500 genetic markers spanning 2345 cM. Using the information of the linkage map, two different chromosomal regions (LG1 and LG3) responsible for sex determination were identified in these species (O. niloticus and O. aureus). BAC clones containing genetic markers in the sex-determining regions were isolated. Shotgun and end-sequences from these BACs identified syntenic regions among Fugu, tilapia, and human. A few genes such as a DEAD box protein, Sox family, and a LIM/homeobox, seem to be good candidates for sex-determining genes, and will need further study. AFLP (amplified fragment length polymorphism)/BSA (Bulked segregant analysis) technique was performed to add more markers in the sex-determining region in O. niloticus. This method appeared to be not so efficient in this study, because, although 3 of 128 selective primer pairs were informative, none of them were closer to sex than the markers that were already identified in the sex-determining region. So, more markers should be developed to further fine map the sex-determining genes within the region

Self-esteem, propensity for sensation seeking, and risk behaviour among adults with tattoos and piercings

Background: In recent years, increasing numbers of adults and adolescents have opted to undergo tattoo and piercing procedures. Studies among adolescents with tattoo and piercing have usually explored the relationship between one factor and the decision to have tattoos and/or piercings. The aim of this study was to determine relationships between body cosmetic procedures and selfesteem, propensity for sensation seeking, and risk behaviours among adults. Materials and Methods: The subjects were divided into two groups, i.e., those with (n=429) and those without tattoos/piercings (n=237), and self-esteem, propensity for sensation seeking, and risk behaviour were compared between the two groups using self-report questionnaires. To analyse differences in self-esteem and the propensity for sensation seeking, general characteristics were statistically adjusted. In addition, general characteristics, self-esteem, and propensity for sensation seeking were statistically adjusted to determine differences in the propensity for risk behaviour between the two groups. Results: Significant differences were observed in age, marital status, income level, occupation, values or sensitivity to fashion, and educational level between the group with and that without tattoos/ piercings. There was no significant difference in self-esteem, whereas there were significant differences in the propensity for sensation seeking and risk behaviour between the two groups. Conclusions: Continuous attention to, and interest in, the increased incidence of tattooing and piercing are necessary, especially in terms of public interventions for health education and health promotion, as these forms of self-adornment are associated with behaviours that pose a risk to health

Quasi-Eigenstate Evolution in Open Chaotic Billiards

We experimentally studied evolution of quasi-eigenmodes as classical dynamics undergoing a transition from being regular to chaotic in open quantum billiards. In a deformation-variable microcavity we traced all high-Q cavity modes in a wide range of frequency as the cavity deformation increased. By employing an internal parameter we were able to obtain a mode-dynamics diagram at a given deformation, showing avoided crossings between different mode groups, and could directly observe the coupling strengths induced by ray chaos among encountering modes. We also show that the observed mode-dynamics diagrams reflect the underlying classical ray dynamics in the phase space.Comment: 4 pages, 4 figure

Nutritional and neuroprotective characterization of 'Tadanishiki' yuzu according to harvesting period or extraction condition

The present study investigated the phenolic profile, antioxidant activity, and neuroprotective properties of ‘Tadanishiki’ yuzu (Citrus junos, a seedless variety of yuzu) according to harvesting period and extraction condition. High-performance liquid chromatography (HPLC) was used to identify the functional components. To evaluate the neuroprotective properties, scopolamine was used to induce cholinergic dysfunction in human neuroblastoma SH-SY5Y cells pretreated with yuzu extracts. Among the harvesting periods, September provided the optimum fruit weight of yuzu and relatively high amounts of total phenolics (3.67 mg/g DW), flavonoids (10.13 mg/g DW), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (29.10 μg Vit. C eq.). Of the functional compounds, hesperidin (13.57 mg/100 g DW) and naringin (5.84 mg/100 g DW) were the highest in 5% (w/v) yuzu extracted with 80% ethanol and this extract showed the highest DPPH (289.2 μg Vit. C eq.) scavenging activity. This same extract showed the highest cell viability and lowest cortisol or acetylcholinesterase content in scopolamine-treated SH-SY5Y cells. These results indicate that ‘Tadanishiki’ yuzu harvested in September should be extracted at 5% (w/v) yuzu with 80% EtOH, and this extract might be useful for application as a natural functional additive

Development of a hybrid magnetic resonance/computed tomography-compatible phantom for magnetic resonance guided radiotherapy

The purpose of the present study was to develop a hybrid magnetic resonance/computed tomography (MR/CT)-compatible phantom and tissue-equivalent materials for each MR and CT image. Therefore, the essential requirements necessary for the development of a hybrid MR/CT-compatible phantom were determined and the development process is described. A total of 12 different tissue-equivalent materials for each MR and CT image were developed from chemical components. The uniformity of each sample was calculated. The developed phantom was designed to use 14 plugs that contained various tissue-equivalent materials. Measurement using the developed phantom was performed using a 3.0-T scanner with 32 channels and a Somatom Sensation 64. The maximum percentage difference of the signal intensity (SI) value on MR images after adding K2CO3 was 3.31%. Additionally, the uniformity of each tissue was evaluated by calculating the percent image uniformity (%PIU) of the MR image, which was 82.18 ±1.87% with 83% acceptance, and the average circular-shaped regions of interest (ROIs) on CT images for all samples were within ±5 Hounsfield units (HU). Also, dosimetric evaluation was performed. The percentage differences of each tissue-equivalent sample for average dose ranged from -0.76 to 0.21%. A hybrid MR/CT-compatible phantom for MR and CT was investigated as the first trial in this field of radiation oncology and medical physics