Preparation of high molecular weight DNA from hermatypic corals and its use for DNA hybridization and cloning

Previous attempts to extract high molecular weight DNA from hermatypic corals have failed because the starting material was mature tissue. The following paper describes the isolation of DNA from coral sperm which is of high molecular weight, and is suitable for DNA hybridization, digestion with restriction endonucleases and cloning. Gross DNA hybridization and hybridization with cloned repetitive DNA was used to investigate relatedness amongst members of the scleractinian coral family Acroporidae. Acropora formosa and A. pulchra were found to share a common (highly homologous) DNA sequence repeat; a related but less homologous sequence was present in A. latistella, and no homologous sequence was detected in Montipora digitata. These results imply a close taxonomic relationship between A. formosa and A. pulchra, and suggest that molecular criteria of this sort will be extremely useful in coral taxonomy.     

Cadmium bioaccumulation in organs of the scallopMizuhopecten yessoensis

Cadmium and Zinc content was determined in organs of the Japanese scallopMizuhopecten yessoensis, collected in 1984 from the Sea of Japan and aged between 1 and 8 yr. Under conditions of background Cd, Cd concentration in hepatopancreas and kidney increased linearly with age from 39 to 400µg g^?1 dry wt in hepatopancreas, and from 100 to 640µg g^?1 dry wt in kidney. Such a pattern was not determined for Zn. Cd concentration in muscle, mantle and gill did not exceed 6µg g^?1 dry wt in the oldest scallops. In subcellular fractions of the hepatopancreas, cytosolic Cd accounted for 71.7% in 1-yr-old scallops and 98.8% in 8-yr-olds. A similar ratio was established for gills, although gill Cd content was an order of magnitude lower. Analysis of Cd distribution in cytoplasmic proteins (of different molecular weight) in the hepatopancreas, showed that the amount of Cd bound to metallothionein-like proteins increases with scallop growth. A considerable amount of Cd also was detected in high molecular weight proteins. Thus, Cd accumulation, with age, in organs of the Japanese scallop is due to metal binding by cytoplasmic proteins.     

Bioaccumulation and elimination of copper in the rock oyster Crassostrea cucullata

The kinetics of copper bioaccumulation in the rock oyster Crassostrea cucullata Born showed that the initial rate of uptake was directly related to metal concentration in the medium. As the accumulation in the tissues increased, the oysters remained closed and the uptake rate fell. At the end of 7 weeks, the average copper concentrations in the tissue were 60.42 g g^-1 and 63.97 g g^-1 wet weight in the 0.01 and 0.05 ppm experimental groups, respectively. The net rate of uptake ranged from 1.76 to 1.97 g g^-1 week^-1 and the rate of copper loss, measured after transferring the oysters into natural sea water, was dependent on the original cooper concentration in the soft parts. The concentration of copper in the tissues declined by 37.38 and 36.56% in the 0.01 and 0.05 ppm experimental groups, respectively. Even after a 7 week period of depuration (self-purification) there was some residual copper left in the tissue. This indicates that accumulation occurs in the tissue more rapidly than cleansing can eliminate it.     

Diet quality affects an attractive white plumage pattern in dark-eyed juncos (Junco hyemalis)

Sexually selected traits that act as signals of quality often display some degree of condition dependence. In birds, condition dependence of ornamental plumage is often mediated by production costs related to acquisition or allocation of dietary resources. White plumage ornaments, however, have often been assumed to be inexpensive because their production requires neither pigment nor specialized feather structure. In male dark-eyed juncos (Junco hyemalis), the size of a white patch on the tail contributes to attractiveness and mating success. Using captive males, we examined the effects of diet quality on the size and brightness of the tail-white patch. After removing four tail feathers to induce replacement, we maintained subjects on a subsistence (low-protein) or enriched (high-protein) diet while induced feathers grew. Birds that received an enriched diet grew their feathers more quickly and grew larger, brighter white patches. Feather growth rate was positively correlated with the increase in the size of the tail-white patch, a relationship that was stronger in the subsistence diet group. However, within diet treatments, faster-grown feathers were slightly duller. Taken together, these results suggest that variation in diet quality may lead to condition-dependent expression of tail white and that condition dependence may be stronger in more stressful environments. We suggest a mechanism by which increased feather growth rate may lead to an increase in the size of the tail-white patch and discuss potential trade-offs between signal size and brightness.     

Changes of Soil Microbiological Properties Caused by Land Use Changing From Rice–Wheat Rotation to Vegetable Cultivation

A survey was done recently in Jiaxing city of Zhejiang Province in the Yangtze River Delta to compare the differences of soil microbiological properties among paddy soils with different land use including continuous open-field vegetable cultivation (OFVC), plastic-greenhouse vegetable cultivation (PGVC) and traditional rice–wheat rotation (RWR). The soil types included are percolating, permeable and waterlogged paddy soils. The results indicate that the microbial flora was markedly changed as the land use changed for all the three soil types. In continuous vegetable cultivation soils, especially in PGVC soils, the bacteria amounts decreased dramatically, but the fungal and actinomyce amounts increased as compared with RWR soils. The dehydrogenase activities decreased significantly in vegetable soils, especially in PGVC soils as compared with RWR soils. The microbial biomass C and the total phospholipid contents (TPL) in vegetable cultivation soil greatly decreased as compared with RWR soils. Biolog analysis indicated that the kinds of carbon sources that could be metabolized by native microbes in PGVC soils greatly decreased as compared with OFVC soils and RWR soils, revealing that microbial diversity had decreased since land use change. The activities of some soil enzymes including urease, invertase and phosphase were all lower in OFVC soils than those in RWR soils, and those in PGVC soils were the lowest. The degradation of microbiological activities in continuous vegetable cultivation soils, especially in PGVC soils, as compared with RWR soils might have been caused by soil acidification and accumulation of salts due to overuse of both organic and inorganic fertilizers in vegetable cultivation.     

Low-temperature oxidation of coal at elevated pressures

A mathematical model is presented to describe steady-state mass transfer and oxidation processes in coal at low temperatures in a fixed-bed flow reactor. The model incorporates the effects of partial pressure of oxygen, temperature and coal particle size, and accounts for the rate of coal oxidation and the composition of oxygenated products at high pressures. This is an important development since previous models did not include the effect of pressure in their formulation. It is found that, when the partial pressure of oxygen increases the rate of oxygen consumption increases accordingly. However, the influence of partial pressure of oxygen on the rate of oxidation is less pronounced when the pressure surpasses 1 MPa. In addition the model predicts that, for a constant partial pressure of oxygen, higher rates of oxygen consumption occur at lower total pressures. The same trends are also found for the concentration of oxygenated products at the reactor outlet. It is suggested that, the variation of partial pressure of oxygen leads to different concentration levels of oxygen at the surface and within the pores of coal particles, substantially affecting the rate of oxidation.     

Survey of polycyclic aromatic hydrocarbons (PAHs) in arterial street air of Hangzhou

ＩｎｔｒｏｄｕｃｔｉｏｎＰｏｌｙｃｙｃｌｉｃａｒｏｍａｔｉｃｈｙｄｒｏｃａｒｂｏｎｓ (ＰＡＨｓ)ａｒｅｗｉｄｅｓｐｒｅａｄｅｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｌｕｔａｎｔｓｉｎｔｈｅａｔｍｏｓｐｈｅｒｅ.Ｔｈｅｙａｒｅｇｅｎｅｒａｔｅｄｉｎｔｈｅｃｏｍｂｕｓｔｉｏｎ .Ｔｈｅｍａｊｏｒｓｏｕｒｃｅｓｉｄｅｎｔｉｆｉｅｄｉｎｃｌｕｄｅｆｏｓｓｉｌｆｕｅｌｓ,ｖｅｈｉｃｕｌａｒｔｒａｆｆｉｃ,ｉｎｄｕｓｔｒｉａｌｐｒｏｃｅｓｓｅｓ,ｓｍｏｋｉｎｇａｎｄｄｏｍｅｓｔｉｃｈｅａｔｉｎｇ (Ｐｅｌｔｏｎｅｎ ,1995) .Ｔ…     

Partition of polycyclic aromatic hydrocarbons on organobentonites from water

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｌｕｍｉｎｏｓｉｌｉｃａｔｅｓｈｅｅｔｓｏｆｂｅｎｔｏｎｉｔｅｐｏｓｓｅｓｓａｎｅｔｎｅｇａｔｉｖｅｅｌｅｃｔｒｉｃａｌｃｈａｒｇｅｃｏｍｐｅｎｓａｔｅｄｆｏｒｂｙｉｎｏｒｇａｎｉｃｅｘｃｈａｎｇｅａｂｌｅｃａｔｉｏｎｓ(ｅ.ｇ.,Ｎａ+ａｎｄＣａ2+),ｗｈｉｃｈｓｔｒｏｎｇｌｙｈｙｄｒａｔｅｄｉｎｔｈｅｐｒｅｓｅｎｃｅｏｆｗａｔｅｒ.Ｓｕｒｆａｃｅｐｒｏｐｅｒｔｉｅｓｏｆｎａｔｕｒａｌｂｅｎｔｏｎｉｔｅｃａｎｂｅｍｏｄｉｆｉｅｄｂｙｓｉｍｐｌｅｉｏｎｅｘｃｈａｎｇｅｗｉ…     

Mosaicism for trisomy 12: Four cases with varying outcomes

Trisomy 12 observed in chorionic villus sampling (CVS) may reflect generalized mosaicism or indicate mosaicism confined to only the placenta. In this report, four cases of trisomy 12 observed in CVS or cultured placental biopsies with varying outcomes are presented. Seven dinucleotide repeat polymorphisms for chromosome 12 were used to determine the chromosome 12 origins in the fetus or child and to delineate the mechanism(s) that gave rise to the trisomy. In two cases (cases A and C), the mosaicism was confined to the placenta, resulting in normal liveborns. Although, in one case, the molecular results suggested an apparent duplication of one paternal chromosome 12 in the placenta, normal biparental inheritance was found in the diploid fetal cell line in both cases. In two other cases (cases B and D), trisomy 12 was observed in both extraembryonic and fetal tissues. In one of these pregnancies, a child was born by Caesarean section at 37 weeks because of intrauterine growth retardation and oligohydramnios, and resulted in neonatal death. Molecular markers and fluorescence in situ hybridization (FISH) revealed low-level trisomy 12 mosaicism in the spleen. In the fourth case, fetal abnormalities were detected on ultrasound and low-level trisomy 12 mosaicism was observed in amniotic fluid cells using conventional cytogenetics and FISH. Molecular markers revealed a maternal meiosis I non-disjunction of chromosome 12 in DNA from a cultured placental biopsy. Although predicting the outcomes of pregnancies involving confined placental mosaicism remains difficult, molecular techniques are valuable tools for distinguishing uniparental from biparental disomy and mechanisms of mosaicism.     

Distribution of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area in China

ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｒａｚｉｎｅ(2ｃｈｌｏｒｏ4ｅｔｈｙｌａｍｉｎｏ6ｉｓｏｐｒｏｐｙｌａｍｉｎｏｓｔｒｉａｚｉｎｅ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｓｅｌｅｃｔｉｖｅｐｒｅａｎｄｐｏｓｔｅｍｅｒｇｅｎｃｅｈｅｒｂｉｃｉｄｅｓｆｏｒｔｈｅｃｏｎｔｒｏｌｏｆｂｒｏａｄｌｅａｆａｎｄｇｒａｓｓｙｗｅｅｄｓ.ＴｈｉｓｈｅｒｂｉｃｉｄｅｉｓｐｒｉｍａｒｉｌｙｕｓｅｄｉｎｃｏｒｎｃｒｏｐｐｉｎｇｓｙｓｔｅｍｉｎＮｏｒｔｈｅａｓｔａｎｄＮｏｒｔｈｏｆＣｈｉｎａ,ａｎｄａｓｏｆｔｅｎｔｉｍ…