Stocking effectiveness of hatchery-released kuruma prawns estimated by two-stage sampling of commercial catch in Ariake Sound, Japan

ABSTRACT:    To evaluate the stocking effectiveness of the kuruma prawn Penaeus japonicus , a two-stage sampling survey of Gensiki bottom-drift-netters was carried out in Ariake Sound, Saga Prefecture, Japan. A total of 471 000 hatchery-produced juveniles, marked by cutting off the right uropods, was released. Thirty-three fishing days were randomly drawn from four boats, which were selected from the 80 boats operating in the fishery. All prawns caught on the selected days were examined, and the hatchery-produced individuals were identified by their regenerated uropods. A telephone survey of all boats was also conducted, to determine the number of fishing days. A total of 286 marked prawns were caught on the survey days for the Saga area in Ariake Sound, from the last half of July to the first half of September 2002. The recapture rate and standard error were estimated at 0.76 ± 0.52%. Economic efficiency was estimated at 0.28 ± 0.02. Strategies for sampling schemes and stock recovery are also discussed.     

Cladistic relationships among the Pleurotus ostreatus complex, the Pleurotus pulmonarius complex, and Pleurotus eryngii based on the mitochondrial small subunit ribosomal DNA sequence analysis

The cladistic analysis of the V4 domain sequences, performed by UPGMA, the neighbor-joining, and parsimony methods, revealed that the 19 Pleurotus strains tested in this study evolved along three lineages, each corresponding to a separate biological species: the Pleurotus ostreatus complex, the Pleurotus pulmonarius complex, and Pleurotus eryngii. Moreover, the cladistic positions of the 3 biological species show that the P. ostreatus complex and P. eryngii were derived from a common ancestor at a later stage of evolution, and that the common ancestor had diverged from the lineage of the P. pulmonarius complex during an earlier evolutionary event. The sequences of the 5 portion of the mt SSU rDNA among the strains of the P. ostreatus complex had 99.2%–99.6% homology. All test strains in the P. pulmonarius complex had completely identical sequences. The homology of the strain sequences between the P. ostreatus complex and the P. pulmonarius complex ranged from 96.0% to 96.3%. The sequence of the strain of P. eryngii showed 97.8%–98.3% and 96.5% homologies with those of the strains in the P. ostreatus and the P. pulmonarius complexes, respectively.     

Authentication of flying-fish-meal content of processed food using PCR-RFLP

Nucleotide sequence and polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the 3′-portion of the mitochondrial 16S RNA gene (rDNA) coding sequence were used to differentiate between flying fishes and other fishes that are frequently used in ago-noyaki production. In this study, we successfully distinguished between flying fishes and the other fishes by combining amplified DNA fragments with universally designed primers and digesting the PCR products with AfaI and MfeI restriction endonucleases. PCR-RFLP of 15 ago-noyaki, 2 noyaki, and 8 other processed flying-fish products were analyzed to authenticate flying-fish content among processed seafood products. After digestion of the PCR products with both enzymes, we found that all ago-noyaki and processed flying fish products contained either two or three DNA fragments of ~200, 300, and 530 bp, and noyaki samples (which do not contain flying fish) contained only one fragment of ~530 bp. Here, we present a new procedure to confirm the content of flying-fish meal in ago-noyaki.     

Quantification of relative flying fish paste content in the processed seafood ago-noyaki using real-time PCR

Real-time polymerase chain reaction (PCR) analysis of the 3′-portion of the mitochondrial 16S RNA gene (rDNA) coding sequence was used to determine flying fish paste in ago-noyaki. We quantified the amount of flying fish paste in ago-noyaki samples using flying fish-specific primers (Tobi16SF3/Tobi16SR) and universal primers (Univ16SF2/Univ16SR2). Using real-time PCR of standard ago-noyaki, a standard equation was obtained (y = 1.08x − 3.20; R ² = 0.977). This equation was then used to estimate the relative flying fish paste contents of eight commercially available ago-noyaki and two similar products. These results verified that the ago-noyaki products that had already been labeled with the E-mark deserved this status.     

Shear-activated nanotherapeutics for drug targeting to obstructed blood vessels

Obstruction of critical blood vessels due to thrombosis or embolism is a leading cause of death worldwide. Here, we describe a biomimetic strategy that uses high shear stress caused by vascular narrowing as a targeting mechanism--in the same way platelets do--to deliver drugs to obstructed blood vessels. Microscale aggregates of nanoparticles were fabricated to break up into nanoscale components when exposed to abnormally high fluid shear stress. When coated with tissue plasminogen activator and administered intravenously in mice, these shear-activated nanotherapeutics induce rapid clot dissolution in a mesenteric injury model, restore normal flow dynamics, and increase survival in an otherwise fatal mouse pulmonary embolism model. This biophysical strategy for drug targeting, which lowers required doses and minimizes side effects while maximizing drug efficacy, offers a potential new approach for treatment of life-threatening diseases that result from acute vascular occlusion.     

Emissions of trace gases (CO2, CO,CH4, and N2O) resulting from rice straw burning

Emissions of trace gases (CO₂, CO, CH₄, N₂O) resulting from rice straw burning were measured by using the open chamber method. The carbon contained in rice straw was mainly released to the atmosphere as CO₂. The percentage of CO₂-C emitted in total C in rice straw was in the range of 57–81%, followed by CO-C (5–9%). The percentages of CH₄-C and N₂O-N in total C and N in rice straw were in the range of 0.43–0.90 and 1.16–1.50%, respectively. In the case of the rice straw which had been left in the field for a period of one month after harvest, emission of imperfect combustible gases such as CO and CH₄ during burning increased slightly, while that of perfect combustible gas, CO₂, was reduced. The amount of CH₄ emission from rice straw burning was comparable to that from paddy fields.     

Linkage analysis among loci for RAPDs, isozymes and some agronomic traits in Brassica campestris L.

Common bean, Phaseolus vulgaris L. is intercropped or relay cropped with maize in many Andean highlands of Colombia and Peru. Breeding beans for the target multiple cropping systems is essential for the development of productive and sustainable agriculture for the Andean smallholders. Outline of the breeding programme should follow the farming system approach with the establishment of on-farm trials and early farmers involvement. Bean breeding is oriented to minimize intercrop competition and to stabilize complementarity with maize. Genetic traits needed for improved varieties are divided as follows : traits not interacting with the cropping systems, traits specific to intercrops and traits related with socioeconomic and seed quality aspects. Screening, prebreeding and recombination nursery are better made under sole cropping while varietal improvement and on-farm trials are conducted under the target multiple cropping systems. Breeding schemes may involve recurrent, pedigree and bulk hybrid selection. The given application concerns the genetic improvement of P. coccineus, P. polyanthus and interspecific hybrids of P. vulgaris for both simultaneous and relay intercropping in Colombia and Peru. Earliness, cold tolerance, resistance to fungus diseases (mainly Ascochyta leaf blight and anthracnosis) and seed yield potential were the major objectives of the bean improvement programme. Priority has been given to the exploitation of the large diversity available in the secondary gene pool of common bean. This revised version was published online in July 2006 with corrections to the Cover Date.     

Preparation and crossing of mating-capable monokaryons via protoplasting of the dikaryotic mycelia of a mycorrhizal mushroom, <Emphasis Type="Italic">Lyophyllum shimeji</Emphasis>

In order to develop a novel method of obtaining monokaryons for a mycorrhizal fungus, Lyophyllum shimeji, monokaryotization of dikaryotic stock culture via protoplast formation and regeneration was performed using 12 dikaryotic stocks. From 6 dikaryotic stocks, a total of 120 monokaryons were isolated, and their mating compatibility was tested. Mating-compatible monokaryons were successfully derived from a dikaryotic stock (NBRC 100325), and monokaryons of only 1 mating type relative to the parental dikaryons were isolated from another 3 strains (MH01710, OK2L-1, and HY7L-1). We successfully prepared monokaryotic stocks via protoplast monokaryotization, a technique that can be used to identify biological species of L. shimeji. This technique could be used for breeding various mycorrhizal mushrooms, including Tricholoma matsutake, for which the preparation of monospore cultures is extremely difficult. Part of this study was presented at the 11th Annual Meeting of the Japanese Society of Mushroom Science and Biotechnology (Asahikawa), September 2007     

Complete mitochondrial DNA sequence of the Japanese flying fish <Emphasis Type="Italic">Cypselurus hiraii</Emphasis>

ABSTRACT:   In this study, to develop a technique that enables authentication of processed seafood, the complete nucleotide sequence of the mitochondrial genome for the Japanese flying fish Cypselurus hiraii was determined. Three segments spanning the entire genome were amplified using polymerase chain reaction, and products were subsequently used as templates for direct sequencing with 60 primers. The genome (16 528 base pairs) was found to contain the same 37 genes (two ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes) as those found in other vertebrate mitochondrial genomes, with the gene order being identical to that typical of vertebrates. A major non-coding region between the tRNA^Pro and tRNA^Phe genes (868 base pairs) appears to be the control (D-loop) region, as it has several conserved blocks characteristic of control regions.