Application of a bioeconomics model to examine sustainability of fishery resources in the global market: the case of octopus resource in Morocco

A study was conducted to examine the long-term relationship among price of fish, harvest level, and resource condition using a bioeconomics model. Data on the annual amount of production and prices of octopus (Octopus vulgaris) in Morocco from 1970 to 2006 are plotted on a diagram to trace annual changes of price and production. The plotted pattern suggests a long-term movement of the yield-price equilibrium along the line of a theoretical long-term supply function curve of the bioeconomics model. The plotted data also suggests that there are four stages of resource exploitation for octopus in Morocco: (1) the underexploited stage from 1970 to 1987 which is characterized by small catch and low prices, (2) the maximum sustainable yield (MSY) stage from 1988 to 1998 which is characterized by moderate catch and intermediate prices, (3) the overexploited stage from 1999 to 2001 which is characterized by large catch and intermediate prices, and (4) the reduced stock stage after 2002 which is characterized by small catch and high prices. This result is consistent with the independent scientific research information on octopus harvested in Morocco. Our study indicates that an analysis of market information (i.e., amount of production and price) could be an effective tool in identifying approximate status of fishery resources.     

Mechanism of reduction of exchangeable aluminum by gypsum application in acid andosols

Mechanism of reduction of exchangeable aluminum in acid Andosols treated with gypsum was studied by using cation exchange resin methods to determine the amount of polymerized aluminum. Two types of acid Andosols were used as test soils: Kitakami light colored Andosol (fine, mixed, mesic, Andic Dystrochrept) and Kawatabi thick high humic Andosol (medial, mesic mixed Alic Pachic Melanudand). Polymerization of aluminum in the soil solution of both Kitakami and Kawatabi Andosols treated with gypsum was suggested based on an analysis using cation exchange resin methods, whereas that in monomer aluminum solution was not detected. Accumulation of polymerized aluminum in both Kitakami and Kawatabi Andosols was determined by using cation exchange resin, and the amounts of polymer aluminum trapped by the resin and the ratio of polymer aluminum to monomer aluminum were increased with the incubation time. The values of CEC which decreased in the Kitakami Andosol after gypsum treatment were almost equivalent to the amounts of cation exchange sites occupied by polymer aluminum ions which were calculated based on the decrease of the values of Y _l. We conclude that the mechanism of reduction of exchangeable aluminum in strongly acid Andosols treated with gypsum is as follows: firstly, exchangeable aluminum adsorbed on the cation exchange sites of soils may be released into the soil solution due to the increase in the ion strength caused by gypsum application, and then monomer aluminum in soil solution may be polymerized in the presence of soil colloidal materials. Consequently, the polymer aluminum formed in the soil solution may be selectively and irreversibly fixed on the cation exchange sites of 2 : 1 clay minerals.     

Richness of Colchic vegetation: comparison between refugia of south-western and East Asia

Background  

Heavy metals, especially copper, nickel, lead and zinc, have adverse effects on terrestrial and in aquatic environments. However, their impact can vary depending on the nature of organisms. Taking into account the ability of heavy metals to accumulate in sediments, extended knowledge of their effects on aquatic biota is needed. In this context the use of model organisms (often unicellular), which allows for rapid assessment of pollutants in freshwater, can be of advantage. Pentachlorophenol has been extensively used for decades as a bleaching agent by pulp- and paper industry. Pentachlorophenol tends to accumulate in the nature. We aim to determine if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies of Chlamydomonas reinhardtii, a motile green unicellular alga. It is discussed if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies.     

Detection of QTLs for traits associated with pre-harvest sprouting resistance in bread wheat (Triticum aestivum L.)

Pre-harvest sprouting (PHS) is one of the serious problems for wheat production, especially in rainy regions. Although seed dormancy is the most critical trait for PHS resistance, the control of heading time should also be considered to prevent seed maturation during unfavorable conditions. In addition, awning is known to enhance water absorption by the spike, causing PHS. In this study, we conducted QTL analysis for three PHS resistant related traits, seed dormancy, heading time and awn length, by using recombinant inbred lines from ‘Zenkouji-komugi’ (high PHS resistance) × ‘Chinese Spring’ (weak PHS resistance). QTLs for seed dormancy were detected on chromosomes 1B (QDor-1B) and 4A (QDor-4A), in addition to a QTL on chromosome 3A, which was recently cloned as TaMFT-3A. In addition, the accumulation of the QTLs and their epistatic interactions contributed significantly to a higher level of dormancy. QDor-4A is co-located with the Hooded locus for awn development. Furthermore, an effective QTL, which confers early heading by the Zenkouji-komugi allele, was detected on the short arm of chromosome 7B, where the Vrn-B3 locus is located. Understanding the genetic architecture of traits associated with PHS resistance will facilitate the marker assisted selection to breed new varieties with higher PHS resistance.     

A weeding-duration model for <Emphasis Type="Italic">Larix kaempferi</Emphasis> plantations in Hokkaido,northern Japan

In this study, a weeding-duration model for Larix kaempferi plantations was developed that employs a generalized linear model. The number of years that weeding is necessary is the response variable, and elevation, slope, maximum snow depth, annual precipitation, geological type, soil type, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geological type, soil type, slope aspect, and vegetation type are categorical data. We assumed a Poisson distribution for the response variable. The link function was log. Among the models that could be developed from these variables, we chose the model with the smallest Akaike’s information criterion (AIC). The weeding-duration model can be written as follows: years that weeding is necessary = Exp (−0.0172833 × site index + 0.0014053 × maximum snow depth (cm) + 1.7417731). The results of this study imply that weeding of Larix kaempferi plantations is needed for more years as the maximum snow depth increases and fewer years as the site index increases. This model is useful for cost–benefit analyses of afforestation or reforestation with Larix kaempferi.     

Population structure of relict Metasequoiaglyptostroboides and its habitat fragmentation and degradation in south-central China

The relict dawn redwood Metasequoia glyptostroboides Hu et Cheng is endemic to the region bordering Hubei and Hunan provinces and Chongqing municipality in south-central China. It is critically endangered. We investigated its population size and age structure, and provided a comparison to the study of Chu and Cooper (1950), documenting the changes of the past 60 years. Our study included all the known wild individuals of the species as well as analyses of the floristic diversity of their habitats. In the last 41 years, habitat changes have effectively ended recruitment of M. glyptostroboides and have reduced species richness in direct response to human disturbance, as shown on several indices. The remaining specimens ranged from roughly 41 to some 265 years for an average near 95 years, with heights of 12–51 m averaging 27 m. The detrimental activities of human residents include cultivation of profitable plants in the understory, selective cutting, harvesting of wood for fuel, and thoroughgoing collection of seeds for sale on the active market. Under present environmental conditions and land use, the dawn redwood will not maintain its natural range in south-central China. Our work detailing the plant populations in the habitats of this living fossil will be useful in establishing priorities for its recovery and conservation.     

Kinetic study of the quenching reaction of singlet oxygen by Pyrroloquinolinequinol (PQQH(2), a reduced form of Pyrroloquinolinequinone) in micellar solution

A kinetic study of the quenching reaction of singlet oxygen ((1)O(2)) with pyrroloquinolinequinol (PQQH(2), a reduced form of pyrroloquinolinequinone (PQQ)), PQQNa(2) (disodium salt of PQQ), and seven kinds of natural antioxidants (vitamin C (Vit C), uric acid (UA), epicatechin (EC), epigallocatechin (EGC), α-tocopherol (α-Toc), ubiquinol-10 (UQ(10)H(2)), and β-carotene (β-Car)) has been performed. The second-order rate constants k(Q) (k(Q) = k(q) + k(r), physical quenching and chemical reaction) for the reaction of (1)O(2) with PQQH(2), PQQNa(2), and seven kinds of antioxidants were measured in 5.0 wt % Triton X-100 micellar solution (pH 7.4), using UV-visible spectrophotometry. The k(Q) values decreased in the order of β-Car > PQQH(2) > α-Toc > UA > UQ(10)H(2) > Vit C ～ EGC > EC ? PQQNa(2). PQQH(2) is a water-soluble antioxidant. The singlet oxygen-quenching activity of PQQH(2) was found to be 6.3, 2.2, 6.1, and 22 times as large as the corresponding those of water-soluble antioxidants (Vit C, UA, EGC, and EC). Further, the activity of PQQH(2) was found to be 2.2 and 3.1 times as large as the corresponding activity of lipid-soluble antioxidants (α-Toc and UQ(10)H(2)). On the other hand, the activity of PQQH(2) is 6.4 times as small as that of β-Car. It was observed that the chemical reaction (k(r)) is almost negligible in the quenching reaction of (1)O(2) by PQQH(2). The result suggests that PQQH(2) may contribute to the protection of oxidative damage in biological systems, by quenching (1)O(2).     

Sequence variants at the myostatin gene locus influence the body composition of Thoroughbred horses

Myostatin is a member of the transforming growth factor-β family with a key role in inhibition of muscle growth by negative regulation of both myoblast proliferation and differentiation. Recently, a genomic region on ECA18, which includes the MSTN gene, was identified as a candidate region influencing racing performance in Thoroughbreds. In this study, four SNPs on ECA18, g.65809482T>C, g.65868604G>T, g.66493737C>T, and g.66539967A>G, were genotyped in 91 Thoroughbred horses-in-training to evaluate the association between genotype and body composition traits, including body weight, withers height, chest circumference, cannon circumference, and body weight/withers height. Of these, statistically differences in body weight and body weight/withers height were associated with specific genotypes in males. Specifically, body weight/withers height showed statistically significant differences depending on genotype at g.658604G>T, g.66493737C>T, and g.66539967A>G (P<0.01) in males during the training period. Animals with a genotype associated with suitability for short-distance racing, C/C at g.66493737C>T, had the highest value (3.17 ± 0.05 kg·cm(-1)) for body weight/withers height in March, while those with a genotype associated with suitability for long-distance racing, T/T, had the lowest (2.99 ± 0.03 kg·cm(-1)). In females, the trends in the association of body weight/withers height with genotypes were similar to those observed in males. As the SNPs are not believed to be linked to coding variants in MSTN, these results suggest that regulation of MSTN gene expression influences skeletal muscle mass and hence racing performance, particularly optimum race distance, in Thoroughbred horses.     

Staphylococcus pseudintermedius exfoliative toxin EXI selectively digests canine desmoglein 1 and causes subcorneal clefts in canine epidermis

Staphylococcal exfoliative toxins are known to digest desmoglein (Dsg) 1, a desmosomal cell–cell adhesion molecule, thus causing intraepidermal splitting in human bullous impetigo, staphylococcal scalded skin syndrome and swine exudative epidermitis. Recently, a novel exfoliative toxin gene (exi), whose sequence shares significant homology with previously identified exfoliative toxins, was isolated from Staphylococcus pseudintermedius. Little is known about the pathogenic involvement of this toxin in canine pustular diseases such as impetigo. The aim of this study was to determine whether EXI, the product of the exi gene, digests canine Dsg1 and causes intraepidermal splitting in canine skin. An exi gene was isolated from chromosomal DNA of an S. pseudintermedius strain obtained from a pustule of a dog with impetigo, and was used to produce a recombinant EXI by Escherichia coli expression. When purified recombinant EXI was injected intradermally into normal dogs, it caused the development of vesicles or erosions with superficial epidermal splitting. In addition, the EXI abolished immunofluorescence for Dsg1, but not for Dsg3, at the injection sites. Moreover, the EXI directly degraded baculovirus‐secreted recombinant extracellular domains of canine Dsg1, but not that of canine Dsg3, in vitro. The EXI also degraded mouse Dsg1α and swine Dsg1, but not human Dsg1, mouse Dsg1β and Dsg1γ. Conversely, recombinant SIET, previously designated as S. intermedius exfoliative toxin, did not cause intraepidermal splitting or degradation of any Dsgs. These findings indicate that EXI has a proteolytic activity that digests canine Dsg1, and this characteristic might be involved in the pathogenesis of intraepidermal splitting in canine impetigo.     

Genotyping of Malassezia pachydermatis isolates from canine healthy skin and atopic dermatitis by internal spacer 1 (IGS1) region analysis

Isolates of Malassezia pachydermatis from healthy dog skin and from dogs with atopic dermatitis were molecularly characterized using internal spacer 1 (IGS1) region analyses, and their phospholipase A2 activity and pH growth profiles were then characterized in vitro. The percentage of isolates from healthy dogs that had the following IGS1 subtypes (isotype, %) were as follows: 1A, 6%; 1B, 27%; 1C, 11%; 2A, 6%; 2B, 6%; 3A, 11%; 3C, 3%; and 3D, 24%. In contrast, 9% of isolates from dogs with atopic dermatitis were isotype IB and 91% were isotype 3D, indicating that isolates of subtype 3D were the most prevalent in dogs with atopic dermatitis. Production of phospholipase A2 was statistically higher in isolates of subtype 3D than in the other subtypes. The subtype 3D isolates showed enhanced growth on alkaline medium compared with non-3D subtype isolates. The main clinical sign of canine Malassezia dermatitis is waxy exudates on the skin, which predispose the patient to development of a yeast overgrowth of the subtype 3D. Increased phospholipase A2 production may be involved in the inflammatory process associated with Malassezia dermatitis.