Catch performance of the small prawn pot in terms of entry and escape of the Oriental river prawn Macrobrachium nipponense

ABSTRACT: The entry and escape behavior of prawn Macrobrachium nipponense in relation to the pot may be controlled both by its design and population process in the pot's given interior space. To obtain the basic data on how the population process affects the number of individuals in the pot without bait, a comparative study of the experimental results obtained in the actual fishing ground and calculated values was conducted. The variation pattern in the number of individuals in a pot was consistent with that of the calculated value. The model equation proposed in this study might be effective for evaluating the daily variations in the number of individuals in a pot. The results suggest that both the population process and the pot's design control the entry and escape behavior of the prawn.     

Purification and characterization of sulfotransferase specific to O-22 of 11-hydroxy saxitoxin from the toxic dinoflagellate Gymnodinium catenatum (dinophyceae)

ABSTRACT: A novel sulfotransferase (O-ST), which transferred the sulfate group of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to O-22 of 11-α,β-hydroxy saxitoxin (STX) and produced GTX2 + 3, was purified to homogeneity from the cytosolic fraction of clonal-axenic vegetative cells of the toxic dinoflagellate Gymnodinium catenatum GC21V. After four purification steps, including affinity chromatography and anion exchange chromatography, the enzyme was purified 500-fold and the yield was 4%. On affinity chromatography with a PAP-agarose column, O-ST was observed in the bound fraction, and N-ST specific to N-21 of STX and GTX2 + 3 was found in the unbound fraction. The molecular mass of the purified enzyme was determined by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) to be 65 kDa. Gel filtration chromatography showed a native molecular mass of 67 kDa, indicating that O-ST is a monomeric enzyme. The enzyme was optimally active at pH 6.0 and 35°C. O-ST did not require metal cations for its activity. O-ST required PAPS as the sole source of sulfate. O-ST transferred a sulfate group from PAPS to only O-22 of 11-α,β-hydroxy STX and not to N-21 of these toxins. These observations suggested that two ST, N-ST and O-ST, participate in the sulfation of PSP toxins.     

Effect of sustained release isosorbide dinitrate (EV151) in dogs with experimentally-induced mitral insufficiency

To investigate the hemodynamic effects on seven anesthetized dogs with experimentally-induced mitral insufficiency, isosorbide dinitrate (ISDN) in sustained release form (EV151) was administered at different dosages (0, 2, 8 and 16 mg/kg). The drug administration resulted in altered pulmonary arterial wedge pressure (preload), and cardiac output and total systemic resistance (afterload). Arterial pressure increased in the control group and in animals receiving 2 mg/kg, but decreased in animals 1-2 hr after receiving 8 and 16 mg/kg dosages. Cardiac output increased in animals receiving 2, 8 and 16 mg/kg dosages, with concomitant decreases in total systemic resistance. ISDN caused mild vasodilation at 2 mg/kg and severe vasodilation at 8 and 16 mg/kg. Future experiments on non-anesthetized dogs may be of benefit.     

<Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated transformation for random insertional mutagenesis in <Emphasis Type="Italic">Colletotrichum lagenarium</Emphasis>

Random insertional mutagenesis using a marker DNA fragment is an effective method for identifying fungal genes relevant to morphogenesis, metabolism, and so on. Agrobacterium tumefaciens-mediated transformation (AtMT) has long been used as a tool for the genetic modification of a wide range of plant species. Recent study has indicated that A. tumefaciens could transfer T-DNA not only to plant cells but also to fungal cells. In this study, AtMT was applied to Colletotrichum lagenarium for random insertional mutagenesis. We constructed a binary vector pBIG2RHPH2 carrying a hygromycin-resistant gene cassette between the right and left borders of T-DNA. Optimal co-cultivation of C. lagenarium wild-type 104-T with pBIG2RHPH2-introduced A. tumefaciens C58C1 led to the production of 150–300 hygromycin-resistant transformants per 10⁶ conidia. Southern blot analysis revealed that T-DNA was mainly integrated at a single site in the genome and at different sites in transformants. The T-DNA inserts showed small truncations of either end, but the hygromycin-resistant gene cassette inside the T-DNA was generally intact. The mode of T-DNA insertion described above resulted in highly efficient gene recovery from the transformants by thermal asymmetrical interlaced-polymerase chain reaction. The fungal genomic DNA segments flanking T-DNA were identified from five of eight mutants that had defective melanin biosynthesis. The sequence from one of the segments was identical to that of the melanin biosynthesis gene PKS1 of C. lagenarium, which we previously characterized. These results strongly support our notion that AtMT is a possible tool for tagging genes relevant to pathogenicity in the plant pathogenic fungus C. lagenarium.     

Cloning and characterization of pea apyrases: involvement of <Emphasis Type="Italic">PsAPY1 </Emphasis>in response to signal molecules from the pea pathogen <Emphasis Type="Italic">Mycosphaerella pinodes</Emphasis>

 Two nucleoside triphosphatase (NTPase) cDNA clones were isolated from a cDNA library of Pisum sativum L., cv. Midoriusui. The genes encoding the cDNAs were designated PsAPY1 and PsAPY2. PsAPY1 included the N-terminal amino acid sequence of an NTPase bound to pea cell wall. The phylogenic analysis indicated that PsAPY1 belongs to an NTPase subfamily responsive to environmental stimuli and that PsAPY2 belongs to a discrete subfamily, the physiological role of which is almost unknown. The adenosine triphosphatase activity of recombinant PsAPY1 was regulated by an elicitor and a suppressor from the pea pathogen Mycosphaerella pinodes. Based on these findings, we discuss the role of NTPases in response to biological stresses. Received: May 27, 2002 / Accepted: July 31, 2002     

Seasonal changes of azimuthal,radial, and tree-to-tree variations in sap flux affect stand transpiration estimates in a <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> forest,central Taiwan

Stand transpiration (E) estimated using the sap flux methods is affected by the azimuthal, radial, and tree-to-tree variations of sap flux. Although several studies have examined the relative importance of the three variations in estimating E, the seasonality of the three variations remains unknown. In the current study, we attempted to clarify whether the relative importance of these three variations could show seasonal changes. Using sap flux data measured in a subtropical cloud forest from August 2010 to July 2011, we calculated the differences resulting from omitting the three variations in estimating E. The effects of the three variations in estimating E showed seasonality. The azimuthal and tree-to-tree variations were more pronounced during winter, whereas the radial variation was more pronounced during summer. However, the effect of tree-to-tree variation was consistently much larger than the other two variations throughout the study period. The tree-to-tree variation is more important in estimating E monthly, seasonally and annually than both the azimuthal and radial variations, although all three variations have shown seasonality. In addition, the sensor allocation for summer would be acceptable for the practical estimation of E if aiming at the long time scale.     

<Emphasis Type="Italic">Talaromyces wortmannii</Emphasis> FS2 emits <Emphasis Type="Italic">β</Emphasis>-caryphyllene,which promotes plant growth and induces resistance

A plant-growth-promoting fungus (PGPF), Talaromyces sp. was isolated from an agricultural field in southwestern Japan. We found that this fungus emitted several terpenoid-like volatiles including β-caryophyllene. Then we investigated the effect of β-caryophyllene on promoting the growth and inducing resistance of Brassica campestris L. var. perviridis. The compound significantly enhanced the growth of seedlings and their resistance to Colletotrichum higginsianum. On the basis of these results, we discuss the role of β-caryophyllene in the activities of PGPF.     

Sapflow characteristics and climatic responses in three forest species in the semiarid Loess Plateau region of China

In the semiarid Loess Plateau region of China, ecosystems are frequently affected by water shortages. Late spring and early summer are periods when forest communities tend to suffer from soil drought. To clarify the water-use strategies of the main species in this area, the xylem sap flow of trees from three species in the field was monitored for three successive periods in summer using Granier-type thermal dissipation probes. Vapor pressure deficit (VPD), solar radiation (R_s) and soil moisture had varying influences on sap flux density (F_d) in the species. Normalized F_d values could be fitted to VPD using an exponential saturation function, but the fit was better with a derived variable of transpiration (VT), an integrated index calculated from VPD and R_s. From differences in model coefficients, the species were roughly divided into two types with contrasting drought sensitivity. The exotic Robinia pseudoacacia was defined as drought-sensitive type. It showed higher sapflow increases in response to rainfall, suggesting a high water demand and high influence of soil water conditions on transpiration. This species showed relatively late stomatal response to increasing VPD. The wide-peak pattern of diurnal sapflow course also suggests relatively low stomatal regulation in this species. The drought-insensitive type consisted of the naturally dominant Quercus liaotungensis and an indigenous concomitant species, Armeniaca sibirica, in the forest. The sap flow of these species was not very sensitive to changes in soil water conditions. The results suggest that typical indigenous species can manage the water consumption conservatively under both drought and wet conditions. Variations in water use strategies within indigenous species are also detected.