Habitat use and movement of hatchery-reared F2 Mekong giant catfish in the Mae Peum reservoir, Thailand, studied by acoustic telemetry

The horizontal and vertical movements of eight immature hatchery-reared (F2) Mekong giant catfish Pangasianodon gigas were monitored using acoustic telemetry in the Mae Peum reservoir, Thailand, from September to December 2005. All tagged fish were successfully monitored throughout the study period. All fish moved throughout the reservoir for approximately 1 month after release. Subsequently, their utilized areas became small, and the fish utilized deep areas of the reservoir. The fish displayed diel spatial movement patterns between deep areas in the day and shallow areas in the night. The vertical movements of the fish were related to the environment declination such as existence of hypoxic water and thermocline. Our results suggest that the establishment of a protected area in addition to conventional fisheries regulations may sustain the fish population in this reservoir.     

Seasonal potential fishing ground prediction of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific

We explored the seasonal potential fishing grounds of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific using maximum entropy (MaxEnt) models fitted with squid fishery data as response and environmental factors from remotely sensed [sea surface temperature (SST), sea surface height (SSH), eddy kinetic energy (EKE), wind stress curl (WSC) and numerical model‐derived sea surface salinity (SSS)] covariates. The potential squid fishing grounds from January–February (winter) and June–July (summer) 2001–2004 were simulated separately and covered the near‐coast (winter) and offshore (summer) forage areas off the Kuroshio–Oyashio transition and subarctic frontal zones. The oceanographic conditions differed between regions and were regulated by the inherent seasonal variability and prevailing basin dynamics. The seasonal and spatial extents of potential squid fishing grounds were largely explained by SST (7–17°C in the winter and 11–18°C in the summer) and SSS (33.8–34.8 in the winter and 33.7–34.3 in the summer). These ocean properties are water mass tracers and define the boundaries of the North Pacific hydrographic provinces. Mesoscale variability in the upper ocean inferred from SSH and EKE were also influential to squid potential fishing grounds and are presumably linked to the augmented primary productivity from nutrient enhancement and entrainment of passive plankton. WSC, however, has the least model contribution to squid potential fishing habitat relative to the other environmental factors examined. Findings of this work underpin the importance of SST and SSS as robust predictors of the seasonal squid potential fishing grounds in the western and central North Pacific and highlight MaxEnt's potential for operational fishery application.     

Comparison of plasma concentrations of estradiol-17β and progesterone, and conception in dairy cows with cystic ovarian diseases between Ovsynch and Ovsynch plus CIDR timed AI protocols

The objectives of this study were 1) to determine the effects of adding a CIDR to the Ovsynch protocol on plasma concentrations of estradiol-17β and progesterone and conception in dairy cows with cystic ovarian diseases and 2) to examine associations among the estradiol-17β and progesterone concentrations and conception. Cows were diagnosed as having cystic ovarian diseases if they were found to have a cystic follicle (diameter ≥25 mm) without a corpus luteum by two palpations per rectum with an interval for 7 to 14 days. They were treated with either the Ovsynch (GnRH on Day 0, PGF(2α) on Day 7 and GnRH on Day 9, with AI on Day 10; n=15) or Ovsynch+CIDR protocol (Ovsynch protocol plus a CIDR from Day 0 to Day 7; n=23). Plasma estradiol-17β concentrations were determined on Days 0, 7 and 9, and plasma progesterone concentrations were determined on Days 0, 7, 9 and 17. The plasma estradiol-17β and progesterone concentrations at all of the days examined and conception rates did not differ significantly between the two timed AI protocols. The progesterone concentrations on Day 17 and conception rates were lower (P<0.05) for cows with low concentrations of estradiol-17β (<2 pg/ml) on Day 9 than for cows with high concentrations of estradiol-17β (≥2 pg/ml). The present study suggests that, in dairy cows with cystic ovarian diseases, addition of a CIDR to the Ovsynch protocol had no remarkable effects on plasma estradiol-17β and progesterone concentrations during and after the treatments or on conception after timed AI. This study indicates that the low plasma estradiol-17β concentration at the second administration of GnRH in the protocols can be a predictor for impaired luteal formation and lower likelihood of pregnancy in dairy cows with cystic ovarian diseases.     

Comparison of the peripheral blood leukocyte population between Japanese Black and Holstein calves

Japanese black (JB) calves have greater susceptibility to infectious diseases compared to Holstein (Hol) calves. In order to clarify the differences in cellular immune status between JB and Hol calves, the leukocyte population and lymphocyte proliferative ability were analyzed. In total 200 healthy calves, 1 day to 14 weeks of age, were examined: 105 JB and 95 Hol calves. Lower numbers in peripheral blood and percentage in peripheral blood mononuclear cells of CD3⁺TcR1‐N12⁺ T cells and major histocompatibility complex class‐II⁺CD14^‐ B cells were observed in the JB compared to the Hol. The percentage of TcR1‐N12⁺CD25⁺ T cell in the JB was significantly lower than that of the Hol at 4–6, and 8–10 weeks. Interleukin (IL)‐2 sensitivity in the JB was lower than that in the Hol, and significant differences were observed in age groups of 6–8 weeks and 10–14 weeks. These findings indicated that the lower numbers of γδ T cells and B cells in the JB compared to the Hol might be associated with the specificity of the immune systems in JB calves.     

Homozygosity of single nucleotide polymorphisms in the 3′ region of the canine estrogen receptor 1 gene is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas

Differences in the distribution of single nucleotide polymorphisms (SNPs) and haplotypes in the estrogen receptor α gene (ESR1) were examined in Miniature Dachshunds (n = 48), Chihuahuas (n = 20) and Toy Poodles (n = 18). Five DNA fragments located in the 40‐kb region at the 3′ end of ESR1 were amplified by polymerase chain reaction and were directly sequenced. We compared allele, genotype and estimated haplotype frequencies at each SNP in the 3′ end of ESR1 for these three breeds of small dog. The frequency of the major allele and the genotype frequency of the major allele homozygotes, were significantly higher in Toy Poodles for five SNPs (SNP #5, #14–17) than in Miniature Dachshunds, and significantly higher in Toy Poodles than Chihuahuas for three SNPs (SNP #15–17). A common haplotype block was identified in an approximately 20‐kb region encompassing four SNPs (SNPs # 14–17). The frequencies of the most abundant estimated haplotype (GTTG) and GTTG homozygotes were significantly higher in Toy Poodles than in the other two breeds. These results imply that homozygosity for the allele, genotype and haplotype distribution within the block at the 3′ end of ESR1 is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas.     

Thin-film transistor fabricated in single-crystalline transparent oxide semiconductor

We report the fabrication of transparent field-effect transistors using a single-crystalline thin-film transparent oxide semiconductor, InGaO3(ZnO)5, as an electron channel and amorphous hafnium oxide as a gate insulator. The device exhibits an on-to-off current ratio of approximately 106 and a field-effect mobility of approximately 80 square centimeters per volt per second at room temperature, with operation insensitive to visible light irradiation. The result provides a step toward the realization of transparent electronics for next-generation optoelectronics.     

Molecular characterization of South and East Asian melon, Cucumis melo L., and the origin of Group Conomon var. makuwa and var. conomon revealed by RAPD analysis

The genetic diversity and relationship among South and East Asian melon Cucumis melo L. were studied by using RAPD analysis of 69 accessions of melon from India, Myanmar, China, Korea, and Japan. The genetic diversity was large in India, and quite small in Group Conomon var. makuwa and var. conomon from East Asia, clearly indicating a decrease in genetic variation from India toward the east. Cluster analysis based on genetic distance classified 17 groups of accessions into two major clusters: cluster I comprising 12 groups of accessions from India and Myanmar and cluster II that included five groups of accessions of Group Conomon var. makuwa and var. conomon from East Asia. Cluster I was further divided into three subclusters, of which subclusters Ib and Ic included small- and large-seed type populations, respectively. Therefore, this division was based on their seed size, not cultivation area. The large-seed type from east India was differently included in the subcluster of small-seed type (Ib). A total of 122 plants of 69 accessions were classified into three major clusters and subclusters: clusters I and II comprised melon accessions mostly from India and Myanmar, and cluster III comprised Group Conomon var. makuwa and var. conomon from East Asia. The frequency of large- and small-seed types was different between clusters I and II, also indicating genetic differentiation between large- and small-seed types. One plant of the small-seed type from east India was differently included in cluster III, and two plants from east India were classified into subcluster IV. These results clearly showed that South Asian melon is genetically differentiated by their seed size, and that small-seed type melon in east India is closely related to Group Conomon var. makuwa and var. conomon.     

Comparison of behavioral characteristics of hatchery-reared and wild red tilefish Branchiostegus japonicus released in Maizuru Bay by using acoustic biotelemetry

ABSTRACT:   In order to establish techniques for the stock enhancement of red tilefish Branchiostegus japonicus , it is important to understand the behavioral characteristic of both hatchery-reared and wild fish. Four hatchery-reared and six wild fish were released and tracked using acoustic biotelemetry in Maizuru Bay, Kyoto, Japan, from August 2003 to February 2004. Data for the four wild fish released and tracked from January 2003 to May 2003 were also referred to for analysis. The released fish moved around in relatively large areas within about 10 days after the release, and then three hatchery-reared and two wild fish settled and stayed within limited areas. Fish of both origins showed strong site fidelity and diel activity patterns, i.e. they were detectable in the day but not at night, probably due to hiding behavior in their burrows at night. However, some discrepancies between fish of both origins were detected by comparing their track terms and activity patterns in detail. These discrepancies are probably attributable to the differences in environmental conditions that the fish had experienced before release.     

Directed movements and diel burrow fidelity patterns of red tilefish <Emphasis Type="Italic">Branchiostegus japonicus</Emphasis> determined using ultrasonic telemetry

ABSTRACT:   Wild red tilefish Branchiostegus japonicus were tracked and/or monitored for up to nearly 3 months in Western Wakasa Bay and Maizuru Bay, Japan, using ultrasonic telemetry to examine their movements and burrow fidelity patterns. In Western Wakasa Bay, it is guessed that fish released in relatively shallow waters, about 30 m deep, actively moved into more suitable deeper habitats after their release. In Maizuru Bay, the fish did not undertake large-scale movements and showed burrow fidelity about 1 month after their release. That is, the fish primarily remained in the burrow, which was constructed in the sea-bottom, during the night and moved outside the burrow during the day. The marked circadian rhythm from Fourier analysis indicated a clear diel movement pattern of the red tilefish.     

Strawberry cultivar identification based on hypervariable SSR markers

We genotyped strawberry cultivars by two newly selected and two previously reported SSR markers. All four markers produced interpretable electropherograms from 75 accessions consisting of 72 Fragaria × ananassa cultivars or lines and three octoploid Fragaria species accessions. These SSR markers were highly polymorphic; in particular, one of the newly developed markers, FxaHGA02P13, was capable of distinguishing all of the accessions except for a mutant strain that was derived from another accession in the set. When two markers were combined, all 48 full-sib individuals could be distinguished. Fingerprinting patterns were reproducible between multiple samples, including the leaves, sepals, and fruit flesh of the same accession. Principal-coordinate analysis of the 75 accessions detected several groups, which reflect taxon and breeding site. Together with other available markers, these SSR markers will contribute to the management of strawberry genetic resources and the protection of breeders’ rights.