Recreational fishery as a conservation tool for endemic Dolly Varden <Emphasis Type="Italic">Salvelinus malma miyabei</Emphasis> in Lake Shikaribetsu,Japan

Recreational angling is a popular leisure activity globally and can be a threat or useful conservation tool depending on the management strategy. Miyabe charr Salvelinus malma miyabei is an endemic fish that inhabits Lake Shikaribetsu, and a management program was established to harmonise recreational fishery and conservation. To examine the suitability of this program, population assessment was conducted with the cooperation of anglers. The population size in 2014 as assessed by tag-and-release angling was estimated to be 105,300 [95% confidence interval (CI) 37,300–178,600], much higher than the reported estimate in 1995. Further, angling mortality was estimated to be quite low. Moreover, no decreasing population trend was detected on analysing 8 years of anglers’ catch data. Consequently, angling has facilitated stock assessments of Miyabe charr under the current program. This case is a good example of recreational angling acting as a conservation tool under appropriate management.     

Abietane-type and labdane-type diterpenoids from the cones of Chamaecyparis obtusa

A novel compound, 8(17),12E,14-labdatrien-19-al (trans-communal), was isolated from ethyl acetate extract of young cones of hinoki (Chamaecyparis obtusa Endl.). The chemical structure of the compound was determined mainly with various nuclear magnetic resonance spectral techniques. Its stereochemistry was determined by derivation to a known compound,trans-communol. In addition to this compound, four known compounds — ferruginol, chamaecydin, 12-hydroxy-6,7-seco-abieta-8,l 1,13-triene-6,7-dial, and frans-communic acid — were isolated. All isolated compounds were subjected to an antifeedant bioassay against the pest insectSpodoptera litura. Results of the bioassay showed that chamaecydin and 12-hydroxy-6,7-seco-abieta-8,11,13-triene-6,7-dial had antifeedant activity.Part of this report was presented at 45th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1995     

Interaction between myostatin and extracellular matrix components

Myostatin, a member of the TGF-β superfamily, is a negative regulator of skeletal muscle mass. We have recently demonstrated that decorin binds to myostatin in vitro , and that immobilized decorin within the collagen matrix prevents myostatin-mediated inhibition of myoblast proliferation. However, little is known about other ECM molecules that bind to myostatin and modulate its activity. Thus, in the present study, we investigated the interaction of several other ECM molecules with myostatin. We here show that fibromodulin, fibronectin and laminin bind to myostatin in the presence of Zn²⁺ with a dissociation constant ( K_D ) of 10⁻¹⁰∼10⁻⁸ mol/L. Fibromodulin shows the highest affinity for myostatin among them. These results suggest that these ECM molecules may modulate myostatin activity like decorin does.     

Evaluation of drag coefficients of poplar-tree crowns by a field test method

To estimate the wind force that causes windthrow damage to a tree, the drag coefficients of actual-sized trees were evaluated by a field test method. In this method, wind velocity and stem deflection were monitored simultaneously. The wind force acting on a tree crown was calculated from stem deflection; stem stiffness was evaluated by conducting tree-bending tests. The results of tests conducted on three poplar trees showed that drag coefficient decreased with an increase in wind velocity. Although the variation in the drag coefficient was large at low wind velocity because of the vibrating behavior of the stem subjected to variable wind force, the variation at wind velocities above 10 m/s was small. The average drag coefficient at a wind velocity of 30 m/s was estimated by the curve-fitting of a power function to the wind velocity-drag coefficient relationship to be 0.102, which was smaller than that of actual-sized conifers studied in previous wind tunnel experiments. The drag coefficients of these crown areas in the defoliation season were smaller than those measured in the leafy season.     

Metabolism of fenitrothion by organophosphorus-resistant and -susceptible house flies, Musca domestica L

The metabolism of fenitrothion was investigated in highly resistant (Akita-f) and susceptible (SRS) strains of the house fly, Musca domestica L. The Akita-f strain was 3500 times more resistant to fenitrothion than the SRS strain. Fenitrothion, topically applied to the flies, was metabolized in vivo far faster in the Akita-f strain than in the SRS strain. In vitro studies revealed that fenitrothion was metabolized by a cytochrome P-450-dependent monooxygenase system and glutathione S-transferases. The former oxidase system metabolized fenitrothion in vitro into fenitrooxon and 3-methyl-4-nitrophenol as major metabolites, and into 3-hydroxymethyl-fenitrothion and 3-hydroxymethyl-fenitrooxon as minor metabolites. Glutathione S-transferases metabolized fenitrothion into desmethylfenitrothion. The cytochrome P-450-dependent monooxygenase system and glutathione S-transferases of the resistant Akita-f strain had 1.4 to 2.2 times and 9.7 times, respectively, as great activities as those of the susceptible SRS strain. These results suggest the importance of glutathione S-transferases in fenitrothion resistance in the Akita-f strain.     

Formation of zinc protoporphyrin IX in Parma-like ham without nitrate or nitrite

Zinc protoporphyrin IX (ZPP) is a characteristic red pigment in meat products that are manufactured without the addition of a curing agent such as nitrate or nitrite. To examine the effects of impurities such as mineral components in sea salt on the formation of ZPP, we manufactured Parmatype dry-cured hams that were salted with refined salt or sea salt and examined the involvement of oxidation-reduction potential (ORP) in the formation of ZPP. The content of ZPP was increased drastically after 40 weeks. Microscopic observation showed strong fluorescence caused by ZPP muscle fiber after 40 weeks. Conversely, heme content varied considerably during processing. ORP increased during processing. However, there was no obvious difference between ham salted with refined salt and that salted with sea salt. Therefore, it was concluded that impurities in sea salt were not involved in the formation of ZPP.     

Insect glutathione S-transferase: Separation of transferases from fat bodies of American cockroaches active on organophosphorus triesters

Several glutathione S-transferases which catalyze the conjugation of reduced glutathione with organophosphorus triesters were separated from fat bodies of adult female American cockroaches, Periplaneta americana (L.). Two transferases (I, V) were active on diazinon and three transferases (II, III, IV) were active on methyl parathion. The transferase (I) active on the pyrimidinyl moiety of diazinon was distinguishable from the other transferases on the O-methyl portion of methyl parathion, as shown by chromatographic properties, and additionally it was almost inactive or less active on 3,4-dichloronitrobenzene, methyl iodide, p-nitrobenzyl chloride, trans-cinnamaldehyde, and 1,2-epoxy-3-(p-nitrophenoxy)propane. Transferase II had high activities with “aryl” and “aralkyl” compounds, transferase III with “epoxide” and “alkene,” and transferase IV with “alkyl,” “aryl,” and “aralkyl” compounds. This indicated that the transferases had overlapping substrate specificities. The molecular weight was 35,000–37,000 for both of the enzymes active on methyl parathion and diazinon. The pH optima with methyl parathion and diazinon were about 8.5 and 6.5, respectively. At a glutathione concentration of 5 mM, Michaelis constants were 0.28 and 0.13 mM for methyl parathion and diazinon, respectively.     

Crystalline clay minerals of the soils derived from recent volcanic ashes in Hokkaido,Japan

For the past ten years much work has been carried out on clay minerals of volcanic ash soils. Most investigators have reported that allophane is dominant among clay minerals of volcanic ash soils and crystallizes to halloysite or meta-halloysite with the advance of weathering (1–8). On the other hand, UCHIYAMA, MASUI and ONIKURA (1960) found that montmorillonite predominates in the clay fraction of volcanic ash soil in Kawatabi (9). Furthermore, MASUI, SHOJI and UCHIYAMA (1966) showed that the major crystalline clay minerals of volcanic ash soils in the Tohoku district are montmorillonite, vermiculite, intergradient montmorillonite-vermiculite and chlorite (10). They also showed that these minerals increase with the advance of weathering and that kaolin minerals are minor constituents.     

Analysis of regulation site and manner of abundant nodulation in a soybean (Glycine max (L.) Merr.) cultivar,kitantusunte, using grafting techniques

To characterize the regulation site and manner of the abundant nodulation in the soybean (Glycine max (L.) Merr.) cv. Kitamusume, three grafting eperiments were carried out as follows: reciprocal wedge grafting and inter-cultivar approach grafting between Kitamusume and a normal nodulating cultivar, Toyosuzu, as well as wedge grafting of scions of the supernodulating mutant En6500 onto either Kitamusume or Toyosuzu rootstock. In the reciprocal wedge grafting, the number of nodules per shoot dry weight and average weight per nodule in the grafted plants were consistent with those exhibited by the genotype of their rootstocks. Approach grafting did not affect the number of nodules per shoot dry weight on either side of the inter-cultivar approachgrafted plant. Although grafting of the mutant scion resulted in the loss of the autoregulatory response from the roots of both cultivars, difference in the number of nodules per g shoot dry weight still remained between the two cultivars. These results suggested that the abundant nodulation in Kitamusume is controlled by the root in a non-systemic manner and is independent of the autoregulation mechanism.