Sampling performance and operational quality of a frame trawl used to catch juvenile fish

SUMMARY: A sampling trawl with a rigid mouth; that is, the frame trawl, was designed so as to catch the large larval and juvenile fish more efficiently. The net consisted of four 13 m panels (nylon multifilament and twine diameter φ 0.75 mm, mesh size 8 mm). The frame of the net's mouth was composed of four stainless steel pipes (length 4 m, diameter φ 76 mm, thickness 5 mm). Several operations were conducted to investigate the capability of catching juveniles. A lot of Sardinops melanostictus juveniles, which are generally difficult to catch, were caught during every operation. Underwater observations proved that juveniles could not elude the capture. The frame trawl requires no special handling and is possible to operate in a rough sea.     

Effect of towing speed and net mouth size on catch efficiency in framed midwater trawls

ABSTRACT:   To investigate fish density using rigid-mouth, towed net gear, such as a framed midwater trawl (FMT), it is necessary to know the catch efficiency. The catch efficiency with an FMT is described as the rate of fish entering the net (entering rate) versus the rate of fish retention, i.e. the mesh selectivity. This study investigated the change in the catch efficiency under several towing conditions using three types of FMT of different net mouth areas (4.0, 12.3, and 16.0 m²) with the same mesh size. The catch efficiency of the FMT was evaluated by comparing catch per unit effort obtained from each towing condition. The catch efficiency of FMT varied with towing speed and net mouth area. Particularly, the effect of net mouth area on the catch efficiency was greater than that of towing speed. Additionally, under the same towing condition, the catch efficiency for large length fish was lower than that for small length fish.     

利用精密作图和DNA纤维荧光原位杂交把灯笼椒抗烟草花叶病毒属病毒L^3基因定位于含高度重复序列的类抗病基因簇的400Kb区（连载）

结果 L^3基因的初步定位 我们首先利用NK群体定位了L^3基因,NK群体是辣椒栽培品种（C．annuumcultivar）和从灯笼椒（C．chinense）PI152225导入的含有L^3基因的衍生品种种内杂交的F2代群体。对抗PMMoV及敏感的F2后代的大量DNA进行三轮AFLP分析发现了应用7个组合的选择性PCR引物扩增到8个多态性DNA片段。从其中得到了两个SCAR标记。     

Induction of superovulation using inhibin antiserum and competence of embryo development in wild large Japanese field mice (Apodemus speciosus)

Seasonally, bred wild mice provide a unique bioresource, with high genetic diversity that differs from wild‐derived mice and laboratory mice. This study aimed to establish an alternative superovulation method using wild large Japanese field mice (Apodemus speciosus) as the model species. Specifically, we investigated how the application of inhibin antiserum and equine chorionic gonadotropin (IASe) during both the reproductive and non‐reproductive seasons impact the ovulation rate and competence of embryo development after in vitro fertilization (IVF) with fresh and cryopreserved sperm. When the wild mice were superovulated by injecting eCG followed by human chorionic gonadotropin (hCG), few oocytes were collected during the reproductive and non‐reproductive seasons. In comparison, the number of ovulated oocytes was dramatically enhanced by the administration of IASe, followed by isolation of ovulated oocytes 24 hr after 30 IU hCG administration. The IVF oocytes that were in vitro cultured (IVC) with medium containing serum further developed to the 2‐ and/or 4‐cell stage using both fresh and frozen‐thawed sperm. In conclusion, we successfully established an alternative protocol for collecting ovulated oocytes from wild large Japanese field mice by administering IASe and hCG during both the reproductive and non‐reproductive seasons. This study is the first to develop IVF–IVC wild large Japanese field mice beyond the 2‐ and/or 4‐cell stage in vitro using fresh and cryopreserved sperm. This approach could be used in other species of wild or endangered mice to reduce the number of animals used for experiments, or in maintaining stocks of germ cells or embryos.     

Interaction of cyclodextrins with aliphatic acetate esters and aroma components of La France pear

The interaction between aliphatic acetate esters, which are the major flavor components of La France pear (Pyrus communis L.), and cyclodextrins (CDs) was studied to obtain fundamental data for preparing powdered pear flavor materials. The complexing abilities of alpha-, beta-, or gamma-CD with six kinds of aliphatic acetate esters were compared. alpha-CD formed the highest numbers of complexes with all of the esters. All of the CDs produced complexes more readily with the more hydrophobic esters. Among our samples of freeze-dried pear juice containing dissolved alpha-, beta-, or gamma-CD, the juice with alpha-CD retained the greatest amount of esters. These data demonstrate that alpha-CD is an effective material with which to prepare powdered pear flavor materials. The nuclear Overhauser effect, measured by (1)H NMR spectra, of an alpha-CD-butyl acetate or alpha-CD-hexyl acetate complex showed that these esters were included in the alpha-CD cavity.     

Antioxidant activity of chemical components from sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.) measured by the oil stability index method

A new abietane diterpenoid, 12-O-methyl carnosol (2), was isolated from the leaves of sage (Salvia officinalis L.), together with 11 abietane diterpenoids, 3 apianane terpenoids, 1 anthraquinone, and 8 flavonoids. Antioxidant activity of these compounds along with 4 flavonoids isolated from thyme (Thymus vulgaris L.) was evaluated by the oil stability index method using a model substrate oil including methyl linoleate in silicone oil at 90 degrees C. Carnosol, rosmanol, epirosmanol, isorosmanol, galdosol, and carnosic acid exhibited remarkably strong activity, which was comparable to that of alpha-tocopherol. The activity of miltirone, atuntzensin A, luteolin, 7-O-methyl luteolin, and eupafolin was comparable to that of butylated hydroxytoluene. The activity of these compounds was mainly due to the presence of ortho-dihydroxy groups. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of these compounds showed the similar result.     

Adaptation of feline immunodeficiency virus subtype B strain TM2 to a feline astrocyte cell line (G355-5 cells)

Based on receptor usage during infection, feline immunodeficiency virus (FIV) isolates can be divided into two groups; those that require feline CD134 (fCD134) as a primary receptor in addition to CXCR4 to enter the cells, and those that require CXCR4 only. Most primary isolates, including strain TM2, belong to the former group and cannot infect a feline astrocyte cell line (G355-5 cells) due to a lack of fCD134 expression. In a previous study, we found that G355-5 cells transduced with fCD134 (termed G355-5/fOX40 cells) were susceptible to strain TM2 and the inoculated cells became persistently infected. In this study, we examined the phenotype of the virus prepared from the persistently infected cells (termed strain TM2PI). Intriguingly, strain TM2PI replicated well in na?ve G355-5 cells and the inoculated G355-5 cells (termed G355-5/TM2PI cells) became persistently infected. The infection of TM2PI in G355-5 cells was inhibited by CXCR4 antagonist AMD3100 and TM2PI infected other fCD134-negative, CXCR4-positive cell lines, FeTJ and 3201 cells. Four amino acid substitutions were found in the Env protein of the strain TM2PI when compared with that of the parental strain TM2. Among the substitutions, the Env amino acid position at 407 of TM2PI was substituted to lysine which has been known to be responsible for the FIV tropism for Crandell feline kidney cells. The strain TM2PI will be useful for studying the receptor switching mechanism and FIV pathogenesis in cats.     

Application of the slope‐ratio growth assay technique to estimate tryptophan availability in soybean meal fed to young rats

The slope‐ratio assay for rat was used to determine whether tryptophan (Trp) availability in soybean meal (SBM) is affected by the presence of other amino acids (AAs). In a preliminary study, rats were fed graded levels of Trp‐supplemented diets to establish the Trp concentration range over which the weight gain response was linear. This range was found to be from 0.04% to 0.12% Trp. Subsequently, rats were fed basal (0.045% Trp) or Trp‐supplemented diets from three different sources: l ‐Trp alone, SBM, or l ‐Trp mixed with other AAs to reflect AA levels in the test SBM (AA‐mix). Weight gain in rats increased linearly with supplemental Trp intake (p < .05) for all Trp sources. Compared to the slope achieved with l ‐Trp alone, the estimated availability of Trp in SBM was 84.4%, while for the AA‐mix it was 93.4%. It is evident that the 6.6% reduction in l ‐Trp availability in AA‐mix is due to metabolic costs derived from excess levels of other AAs beside Trp, given that the absorption of crystalline l ‐Trp in the small intestine is 100%. In conclusion, the Trp availability of SBM was estimated to be around 90.4% (i.e., 84.4/93.4 × 100) after correcting for the effects of the other AAs in SBM.     

Endogenous gibberellins and their effects on flowering and stem elongation in cabbage (Brassica oleracea var. capitata)

Summary

Endogenous gibberellins were extracted from cabbage shoots and were analysed using gas chromatography and mass spectrometry. Nine gibberellins (GA₁, GA₁₉, GA₂₀, GA₄₄, GA₁₂, GA₄, GA_15, GA₂₄ and GA₂₅) were identified. Two gibberellin biosynthesis pathways were suggested, an early-13-hydroxlyated pathway and a non-13-hydroxylated pathway, to operate in cabbage shoots. GA₁, GA₄ and prohexadione calcium, a gibberellin biosynthesis inhibitor, were applied to the shoot tip of cabbage ‘Sousyu’ and ‘Kinkei No.201’ with or without cold treatment. Without cold treatment, stem elongation was increased by gibberellins and was suppressed by prohexadione calcium in both cultivars. But prohexadione calcium treatment, followed by gibberellin, promoted stem elongation more than gibberellin alone. Flowering was not induced by gibberellin or prohexadione calcium without cold treatment. When gibberellin and prohexadione calcium were applied during a cold treatment, stem elongation after the cold treatment was increased by gibberellins and was suppressed by prohexadione calcium in both cultivars. Flower bud appearance was promoted by GA₁ and GA₄ in ‘Sousyu’, but in ‘Kinkei No. 201’ only GA₄ was markedly effective. Inhibition of stem elongation and delay of flower bud appearance by prohexadione calcium were overcome by applying GA₁ or GA₄. Neither gibberellin nor prohexadione calcium treatment changed the number of leaf nodes at anthesis. These results indicated that stem elongation and flower bud development are regulated by gibberellins, but gibberellins might have little effect on flower induction.     

Population study and validation of paternity testing for Thoroughbred horses by 15 microsatellite loci.

Microsatellite 15 TKY System was characterized for parentage verification of horse registry. The Microsatellite 15 TKY System was constructed by using 15 microsatellites, TKY279, TKY287, TKY294, TKY297, TKY301, TKY312, TKY321, TKY325, TKY333, TKY337, TKY341, TKY343, TKY344, TKY374, and TKY394, to provide stringent PCR-based microsatellite typing specifically optimized for multicolor fluorescence detection. The Microsatellite 15 TKY System showed good resolutions for 250 unrelated Thoroughbred horses, and the probability of exclusion (PE) at each microsatellite ranged from 0.437 to 0.621, resulting in a total PE value of 99.998% for Thoroughbred horses. These results indicated that the Microsatellite 15 TKY System is useful for paternity testing of Thoroughbred horses. A paternity testing case for a Thoroughbred horse family, in which candidate sires had close relations, was analyzed using the Microsatellite 15 TKY System. In this case, the Microsatellite 15 TKY System excluded paternity of a false sire. We concluded that the Microsatellite 15 TKY System can give sufficient and reliable information for paternity testing.