Effects of light quality on conidiophore formation of the melon powdery mildew pathogen <Emphasis Type="Italic">Podosphaera xanthii</Emphasis>

The lengths of conidiophores in fungal colonies of the melon powdery mildew pathogen Podosphaera xanthii Pollacci KMP-6 N cultured under greenhouse (natural) conditions differed markedly from those cultured in a growth chamber. We hypothesized that light wavelength was responsible for the differences in conidiophore length. In this study, we examined the effects of light-emitting diode (LED) irradiation (purple, blue, green, orange, and red light) and white light on colony development and conidiophore formation in KMP-6 N using a stereomicroscope and a high-fidelity digital microscope. Colonies on leaves were flat under greenhouse conditions and under red LED light irradiation but were stacked under growth chamber conditions and under purple, blue, green, and orange LED light irradiation. In addition, KMP-6 N formed catenated conidia comprising six conidia per conidiophore under greenhouse conditions and red light but more than seven conidia per conidiophore under growth chamber conditions and purple, blue, green, and orange light. Furthermore, almost none of the conidia on top of the conidiophores grown under blue light were fully constricted. Therefore, these fungi could not scatter their conidia and spread infection. This is the first report of the effects of LED lights on conidiophore formation in the melon powdery mildew fungus P. xanthii. The results provide insight into the mechanisms underlying the responses of conidiophores to light of specific wavelengths and conidial scatter from conidiophores of melon powdery mildew fungi.     

Development of an adaptive marine ecosystem management and co-management plan at the Shiretoko World Natural Heritage Site

The Marine Management Plan for the Shiretoko World Natural Heritage Site, Japan, provides a case study for adaptive marine ecosystem management and co-management of coastal fisheries. Shiretoko was the third World Natural Heritage Site registered in Japan and earned this title because of its (i) formation of seasonal sea ice at some of the lowest latitudes in the world, (ii) high biodiversity, and (iii) many globally threatened species. The natural resource management plan of the Shiretoko site is characterized by transparency and consensus building, because (i) UNESCO and IUCN require that the plan be sustainable and (ii) the Government of Japan has guaranteed local fisheries that there will be no additional regulations included in the plan. The Marine Management Plan describes which species and factors are monitored, how these data are evaluated, and how the benchmarks specified by ecosystem management are determined. The plan will provide a valuable example for the establishment of “environment-friendly fisheries” in Japan and other countries, because it includes voluntary activities by resource users that are suitable for use in a local context, flexible to ecological/social fluctuations, and efficiently implemented through increased legitimacy and compliance. This approach is appropriate for coastal communities where a large number of small-scale fishers catch a variety of species using various types of gear. We develop a method to evaluate fisheries integrity by-catch and yield data.     

Tryptophan synthesis block-associated sugar response, a physiological marker for rapid selection of Arabidopsis thaliana transformants, marked with feedback-inhibition-insensitive anthranilate synthase gene

The feedback-insensitive anthranilate synthase (AS) gene was used as a selection marker for transformants of Arabidopsis thaliana . The mutant gene ( mAS1-2 ) was constructed by substituting nucleotide at the effector-binding site of the intrinsic AS gene via PCR-mediated site-directed mutagenesis and flanked with the myrosinase promoter pyk10 to drive its expression during initial root elongation. This inducible gene cassette was first introduced into Agrobacterium tumefaciens and then delivered into A. thaliana by floral-dip inoculation. 5-methyltryptophan (5-MT) inhibited AS and suppressed seedling growth of wild type plants as a result of tryptophan starvation. With the addition of sucrose (10 mg/ml), 5-MT inhibited cotyledon opening and caused anthocyanin to accumulate in juvenile seedlings. The present mutant reversed the tryptophan starvation caused by 5-MT and blocked subsequent sugar responses. The sugar responses were detected in non-transformed plants grown on a selection medium containing 10 mg/ml of sucrose and 10 μg/ml of 5-MT after 3 days of incubation. Thus, true transformants could be selected after a short incubation, compared to the conventional kanamycin-selection method that did not eliminate all non-transformed plants.     

MARINE FISH PRODUCTION AND MARKETING FOR A CHINESE FOOD MARKET: A TRANSACTION COST PERSPECTIVE

ABSTRACT

From a transaction cost perspective, this paper shows how the tradition of consuming marine fish by the majority of Hong Kong's Chinese citizens has shaped the means and modes of marketing seafood in Hong Kong. It is argued that consumer preferences stimulate aquaculture as a non-open access measure to bypass state fish marketing regulations. This has resulted in two outcomes. First, the transaction cost savings on metering output quantity and quality under private property have led not only to the collapse of the state monopoly on marine fish marketing, but also to the emergence of the (then new but) currently popular kind of Chinese seafood restaurant in Hong Kong. Second, consumer preferences for variety have shaped the form of coordination between the producer and the consumer. The advantage of market coordination has led to the emergence of a system of wholesaling and retailing rather than vertical integration. Issues concerning the emergence of Hong Kong as a regional live marine fish production and trading centre are discussed in terms of the contribution of local mariculture to sustainable development.     

Actions of quinolizidine alkaloids on Periplaneta americana nicotinic acetylcholine receptors

BACKGROUND: Botanical insecticides do not play a major role as crop protectants, but they are beneficial in some applications. The authors investigated the actions of naturally occurring alkaloids on insect nicotinic acetylcholine (ACh) receptors (nAChRs) by evaluating their abilities to inhibit specific binding of [³H]imidacloprid (IMI) to nerve‐cord membranes from Periplaneta americana L. Two alkaloids were also tested for their actions on nAChRs expressed by cockroach neurons using patch‐clamp electrophysiology. RESULTS: Four natural quinolizidine alkaloids (matrine, sophocarpine, cytisine and aloperine) exhibited more than 50% inhibition of [³H]IMI binding at 10 µM , although other compounds were found to have no or low inhibitory activity. The rank order of potency based on concentration–inhibition curves was cytisine > sophocarpine ≥ aloperine ≥ matrine. Patch‐clamp analysis indicated that sophocarpine and aloperine were not agonists of nAChRs expressed in P. americana neurons, yet, at 10 µM , aloperine, but not sophocarpine, suppressed ACh‐induced inward currents significantly. CONCLUSION: Three of the four natural alkaloids tested possess structural moieties that are necessary for interaction with P. americana nAChRs. Aloperine, which possesses a unique structure and showed a distinctive dose–response curve, was found to act as an antagonist. Appropriate modifications of these alkaloids might result in novel insecticidal nAChR ligands. Copyright © 2008 Society of Chemical Industry     

Reflection and transmission of visible light by sugi wood: effects of cellular structure and densification

Transmittance and reflectance of visible light by sugi wood (Cryptomeria japonica) were investigated in the longitudinal (L) and tangential (T) directions. Transmittance was the highest in the L direction and reflectance was the highest in the T direction, suggesting that structural anisotropy influences transmittance and reflectance. Intra-ring variations observed with a microspectrometer indicated that T transmittance was higher for latewood than for earlywood, but there was no such trend in for L transmittance in which the highest levels occurred near the annual ring boundaries, on either the earlywood or latewood side, and the lowest at the transition from earlywood to latewood. Dependence of L transmittance on wavelength also showed variations according to the intra-ring position. The increasing of transmittance of earlywood at wavelengths?<?500 nm with increasing wavelength was observed, but this was not confirmed for latewood because of absorption by lignin. These observations supported a previously published finding, which was based on measurements in the radial direction, that the number of internal cell wall reflections, rather than density, determines wood lightness. Indeed, in the L direction, most of the incident light passes through lumens in earlywood and through cell walls in latewood, while it is subjected to numerous internal reflections at the interface between lumens and cell walls. This was further confirmed by the transmittance of earlywood being greatly decreased by radial compression.     

Comparisons of hyphal growth of Raffaelea quercivora among four Japanese Fagaceae species

Japanese oak wilt causes widespread oak mortality in Japan. Possible differences in susceptibility to the causal fungus, Raffaelea quercivora, may be due to vessel arrangements in host trees. To clarify whether constitutive defence mechanisms including vessel arrangements or induced defence mechanisms are the main determinants of host susceptibility, we inoculated the fungus into living seedlings or sterilized stem segments of four Japanese fagaceous species. In seedlings, water conductance was assessed with dye. In both seedlings and stem segments, hyphal growth was examined by fluorescence microscopy. In seedlings, the area of non‐conductive sapwood in stem cross sections and hyphal growth differed significantly among species. In the susceptible species Quercus crispula and Quercus serrata, hyphal growth was significantly and positively correlated with the proportion of non‐conductive sapwood. In stem segments, hyphal growth was not significantly different among species or between vessel arrangements and was similar to or greater than that in seedlings. These results suggest that the extent of sapwood colonization by R. quercivora could be used as a marker for susceptibility and that susceptibility is determined mainly by induced defence responses.     

Pilot evaluation of the efficacy of shampoo treatment with ultrapure soft water for canine pruritus

Ultrapure soft water (UPSW) is water in which calcium and magnesium ions have been replaced with sodium ions using a cation‐exchange resin. We recently demonstrated that washing with soap and UPSW reduced the clinical severity of dermatitis and improved the skin barrier function in NC/NgaTnd mice, a murine model for human atopic dermatitis. The purpose of this pilot study was to evaluate the efficacy of shampoo treatment with UPSW for dogs with pruritus. Eleven dogs with pruritus were randomly assigned to two groups depending on whether they received weekly shampoo treatment with UPSW or tap water for 4 weeks. After a washout period, the treatment protocol was switched such that each dog received both treatments. The pre‐treatment and post‐treatment values of the following were compared: pruritus scores assessed by the owners; dermatitis scores recorded by an investigator; and transepidermal water loss (TEWL). Shampoo treatment with UPSW significantly decreased pruritus and dermatitis scores in the dogs, whereas shampoo treatment with tap water did not. In addition, shampoo treatment with UPSW, but not with tap water, significantly reduced TEWL in the dogs. Adverse events due to the treatment were not observed in the dogs. Furthermore, we found that topical application of UPSW for barrier‐disrupted skin caused by tape stripping in healthy dogs decreased TEWL more rapidly than topical application of tap water. Our findings suggest that shampoo treatment with UPSW promotes skin barrier recovery and thus could be considered as a possible therapeutic option in the management of pruritus and dermatitis in dogs.     

Comparison of the immunosuppressive effects of dexamethasone, flunixin meglumine and meloxicam on the in vitro response of calf peripheral blood mononuclear cells

This study compared the immunosuppressive effects of dexamethasone (DEX), flunixin meglumine (FLU) and meloxicam (MEL) on the peripheral blood mononuclear cells (PBMCs) of seven healthy Holstein calves in vitro. DEX significantly inhibited lymphocyte proliferation and expression of interferon (IFN)-γ, interleukin (IL)-2 and IL-4 messenger RNA (mRNA) in comparison with FLU and MEL. FLU and MEL dose-dependently inhibited lymphocyte proliferation, but did not significantly reduce mRNA expression. Our in vitro study indicates that steroidal anti-inflammatory drugs (SAIDs) as well as nonsteroidal anti-inflammatory drugs (NSAIDs) have immunosuppressive effects on calf PBMCs. These findings are important for assessing the indications and complications of NSAIDs in calves.     

Comparison of fertility on intrauterine insemination between cryopreserved ejaculated and cauda epididymal sperm in dogs

The fertility was compared between ejaculated and cauda epididymal sperm sensitized with prostatic fluid in dog after freeze-thawing using the fertility of ova from the contralateral ovary after injection (2 × 10(8) sperm) into dog uterus on the unilateral ovariectomized side, on the basis of the presence or absence of conception. No significant difference was observed in sperm quality after freeze-thawing between the two groups and conception rates were equivalent and low. Therefore, to achieve a high fertility by intrauterine insemination of canine frozen-thawed ejaculated and cauda epididymal sperm, intrauterine insemination on both sides is recommended, rather than insemination with a lot of sperm of the uterine horn on one side.