Highly repeated DNA sequences in the scleractinian coral genusAcropora: Evaluation of cloned repeats as taxonomic probes

A plasmid clone containing highly repeated DNA sequence fromAcropora formosa was used to probe slot blots of genomic DNA and Southern blots of Taq I digests from other Acroporidae. Homologous repeated DNA sequences were detected in 12 otherAcropora species, but not in three other species of Acroporidae (Astreopora sp.,Montipora digitata andM. aequituberculata). Slot-blot experiments indicated that the repeated sequences inAcropora latistella, A. tenuis, A. longicyathus andA. nobilis were distantly homologous with the clonedA. formosa repeat, whereas those inA. pulchra, A. millepora, A. valida, A. hyacinthus andA. microphthalma were highly homologous with this probe and those inA. digitifera were intermediate. Relatedness of the highhomology group toA. formosa was assessed by comparison of Taq I-digestion patterns. The predominant repeats inA. pulchra andA. hyacinthus had two Taq I sites per repeat unit (as didA. formosa), whereas repeats inA. digitifera, A. valida andA. microphthalma had one Taq I site per repeat; the pattern given byA. millepora implied that its highly homologous repeat units contained either one or two Taq I sites. Within the high-homology group, decreasing number of Taq I sites implies increasing taxonomic distance fromA. formosa. The relatedness series implied by these data differs from that based on morphological criteria.     

Decomposition and microbial dynamics for standing,naturally positioned leaves of the salt-marsh grass Spartina alterniflora

Decomposition of leaves of smooth cordgrass (Spartina alterniflora Loisel.) was monitored for two cohorts of leaves from September 1984 to May 1985 (autumn and winterspring) at Sapelo Island (31°23 N; 81°17 W). The leaves were tagged in plance at the ligule, rather than cut and placed in litterbags. Dead leaves were not abscised from shoots. Loss of organic mass from the attached leaves was at least 60 to 68% of the orginal values. Fungal mass, as measured by an enzyme-linked immunosorbent assay, formed > 98% of the microbial standing crops in two of three autumn samples, and in all samples for the colder, drier, winterspring cohort. Fungal mass was probably mostly in the form of the mycelium and pseudothecia of an ascomycete, Phaeosphaeria typharum (Desm.) Holm. Fungal dominance of microbial standing crops declined when autumn leaves bent downward and acquired a large sediment content (ash=35% of dry matter); the bacterial crop then rose to 7% of the total microbial crop. Microphotoautotrophic mass was always measurable, but was never more than 2% of the microbial crop. Carbon-dioxide fixation was much lower than carbon-dioxide release, and a substantial portion of the fixation may have been anaplerotic fungal fixation. Threeto 8 wk net fungal productivity (average per day) was much greater (16 to 26 times) than measured instantaneous bacterial productivity (extrapolated to per-day values) early in each decay period. Fungal productivity was negative late in the decay period. Fungal productivity was negative late in the decay period for autumn leaves, and was approximately equal to bacterial productivity late for winter-spring leaves. Net nitrogen immobilization was observed only late in the decay period for autumn leaves, implying that nearly all dead-leaf nitrogen was scavenged into fungal mass after the first sampling interval. Flux estimates for dead-leaf carbon indicated a flow of 11–15% of the original to fungal mass, 2% to bacterial mass, 15–21% to carbon dioxide, 10–12% to dissolved leachage, and 34–36% to small particles; 32–39% remained attached as shreds at the end of the study periods. Salt-marsh periwinkles (Littorina irrorata Say) appeared to be the major shredders of dead leaves and conveyors of leaf-particulate material to the marsh sediment, at least in those parts of the marsh where the snails are densely concentrated (usually areas of short- and intermediateheight cordgrass shoots).     

Gene flow in house mice: Behavior in a population cage

Summary The social behavior of house mice captured from natural populations was studied in an enclosure. Six replicate experiments with observations totalling 344 h were done to contrast the behavior of outbreeders, individuals that have progeny by interdemic reproduction; inbreeders, individuals that have progeny by intrademic reproduction; and nonbreeders. The frequency of outbreeding was also determined.In each replicate, two male and three female commensal house mice, Mus musculus, homozygous for the same allele at the hemoglobin locus, Hbb ^s , were put in half of a population cage. A barrier separated this deme from another deme homozygous for the alternative allele, Hbb^d. The barrier was removed after a month and each experiment continued for a further two months with daily observations.In five of six experiments, the mice from both demes formed one social group and in the sixth experiment, the mice remained in their original demes. In two experiments, outbreeding occurred: females from one deme produced offspring by males from the other deme. In three experiments, inbreeding occurred: females produced offspring by males from the same deme. Soon after the demes had formed one social group in these three experiments, the remaining male in a deme was killed and the experiment terminated; females without a male readily join other demes. The pattern of breeding resulted in a genetically effective size, N _e , that was approximately half of the maximum N _e obtainable with random mating. The social organization of house mice, although structured and characterized by male territoriality, presents no major barrier to gene flow within populations.Affiliative (mount, allogroom, follow) and agonistic (fight, chase, attack) behavior occurring when the barrier was present had no predictive value in determining which mice would be outbreeders. With the barrier absent, outbreeders were the recipients of more affiliative behavior than inbreeders. Male outbreeders initiated more agonistic behavior than inbreeders. Outbreeders engaged in more interdemic affiliative behavior than inbreeders.Contribution no. 362 from the Department of Ecology and Evolution at SUNY, Stony Brook     

Irreversible land use and the preservation of endangered species

An alternative derivation of the irreversibility concept, with an application to the preservation of endangered species, is presented in this paper. The analysis involves a standard intertemporal welfare maximization procedure and is interested in the allocation of land between the production of economic goods and the preservation of species. Conversion of habitat is assumed to be irreversible. It is shown that the existence of utility value for species stocks, combined with increasing severity of the irreversibility constraint implies less conversion of species habitat than would occur in the absence of irreversibility.     

Chemical aspects of mass spawning in corals. I. Sperm-attractant molecules in the eggs of the scleractinian coral Montipora digitata

This paper provides the first evidence for sperm chemotaxis in the Scleractinia. Montipora digitata Dana, 1845 (Scleractinia: Coelenterata) is a hermaphroditic coral which reproduces bi-annually, releasing egg-sperm bundles during the mass spawning at Magnetic Island (19°10S; 146°52E) in late spring-early summer, and autumn each year. The buoyant egg-sperm bundles float to the surface where they break apart, releasing eggs and sperm into the ocean. Fertilisation occurs after 30 min. Unfertilized eggs were collected, washed free of sperm, and freeze-dried. The eggs were extracted with dichloromethane, fractionated by chromatography on silica gel, and the fractions assayed for their ability to attract M. digitata sperm. The active fraction was further fractionated by high-performance liquid chromatography, resulting in the isolation of three highly unsaturated fatty alcohols: (1) dodeca-2,4-diynol; (2) tetradec-13-ene-2,4-diynol; (3) (14Z)-heptadeca-14,16-diene-2,4-diynol. Of these three compounds, only Compound 1 attracted sperm of M. digitata. Synthetic Compound 1, produced from simple precursors by known reactions, possessed sperm-attracting activity comparable to the naturally derived attractant. Preliminary experiments suggest that the natural mixture of Compounds 1, 2 and 3 in the ratio 1:4:9 is more effective in attracting sperm from M. digitata than sperm from other Montipora species. Sperm attractants may act to reduce the incidence of hybridisation between different species of Montipora.     

The effect of ink types and printing processes on flotation deinking efficiency of wastepaper recycling

Wastepaper is the largest fraction of solid waste. Flotation deinking plays an essential role in the product quality and process cost of wastepaper recycling. This paper investigated the effect of ink types and printing processes on flotation deinking. Examination of ink types in this study revealed that newsprint oil-based offset-cold and offset-heat inks contain substantial oil (45 to 60%) and resin (5 to 35%); water-based ink contains water (40%) and resin (polystyrene, 30%); and these inks are liquids with densities around 1 g/cm³ at 25 °C. On the other hand, photocopy and laser-print toners were found to be solid powders with particle diameters of about 20 μm, densities of 1 to 1.5 g/cm³, and a composition that consists primarily of styrene-acrylate copolymers (60 to 90%). Except for water-based ink, which is water soluble, all inks in their initial state are hydrophobic. It was found that for newsprint oil based offset-cold inks there is little change in their surface chemical properties, and their hydrophobic character is retained. These inks in the newsprint wastepaper pulp can be effectively removed by flotation. On the other hand, it was found that during the printing processes, the toner particles undergo polymerization (fusion) and oxidation with the subsequent formation of peroxide bonds due to exposure to heat, light, and oxygen (air). The fusion due to polymerization causes bonding to the paper fibers and the creation of larger toner particle sizes. The oxidation creates a greater polarity at the toner particle surface. These effects account for the poor efficiency in the flotation deinking of office waste. In order to improve office wastepaper recycling, it is evident, based on this study and policy considerations, that there is a need to find ways of improving the efficiency and effectiveness of flotation deinking by modification of the surface properties of printed toner particles, or designing new toner particles.     

Prenatal diagnosis of the derivative chromosome 22 associated with cat eye syndrome by fluorescence in situ hybridization

Cytogenetic studies of cultured amniocytes demonstrated a karyotype of 46, XX/47, XX,+mar. A bisatellited, dicentric, distamycin-DAPI negative, NOR-positive marker was present in 76 per cent of the metaphases examined. Similar markers have been associated with cat eye syndrome (CES). We report on the utilization of fluorescence in situ hybridization (FISH) with a 14/22 a-satellite probe and a chromosome 22-specific cosmid for locus D22S9 to determine the origin of the prenatally detected supernumerary marker chromosome. FISH studies demonstrated that the marker is a derivative of chromosome 22 and enabled us to provide the family with additional prognostic information.     

Road Erosion and Delivery Index (READI): A Model for Evaluating Unpaved Road Erosion and Stream Sediment Delivery

The Road Erosion and Delivery Index (READI) is a new geographic information system–based model to assess erosion and delivery of water and sediment from unpaved road networks to streams. READI quantifies the effectiveness of existing road surfacing and drain placements in reducing road sediment delivery and guides upgrades to optimize future reductions. Roads are draped on a digital elevation model and parsed into hydrologically distinct segments. Segments are further divided by engineered drainage structures. For each segment, a kinematic wave approximation generates runoff hydrographs for specified storms, with discharge directly to streams at road–stream crossings and onto overland‐flow plumes at other discharge points. Plumes are attenuated by soil infiltration, which limits their length, with delivery occurring if plumes intersect streams. Sediment production and sediment delivery can be calculated as a relative dimensionless index. READI predicts only a small proportion of new drains and new surfacing results in the majority of sediment delivery reductions. The model illustrates how the spatial relationships between road and stream networks, controlled by topography and network geometries, influence patterns of road–stream connectivity. READI was applied in seven northern California basins. The model was also applied in a recent burn area to examine how reduced hillslope infiltration can result in increased hydrologic connectivity and sediment delivery.     

Streamflow Forecasting Using Singular Value Decomposition and Support Vector Machine for the Upper Rio Grande River Basin

The current study improves streamflow forecast lead‐time by coupling climate information in a data‐driven modeling framework. The spatial–temporal correlation between streamflow and oceanic–atmospheric variability represented by sea surface temperature (SST), 500‐mbar geopotential height (Z₅₀₀), 500‐mbar specific humidity (SH₅₀₀), and 500‐mbar east–west wind (U₅₀₀) of the Pacific and the Atlantic Ocean is obtained through singular value decomposition (SVD). SVD significant regions are weighted using a nonparametric method and utilized as input in a support vector machine (SVM) framework. The Upper Rio Grande River Basin (URGRB) is selected to test the applicability of the proposed model for the period of 1965–2014. The April–August streamflow volume is forecasted using previous year climate variability, creating a lagged relationship of 1–13 months. SVD results showed the streamflow variability was better explained by SST and U₅₀₀ as compared to Z₅₀₀ and SH₅₀₀. The SVM model showed satisfactory forecasting ability with best results achieved using a one‐month lead to forecast the following four‐month period. Overall, the SVM results showed excellent predictive ability with average correlation coefficient of 0.89 and Nash–Sutcliffe efficiency of 0.79. This study contributes toward identifying new SVD significant regions and improving streamflow forecast lead‐time of the URGRB.     

Can coffee certification schemes increase incomes of smallholder farmers? Evidence from Jinotega,Nicaragua

This paper investigates the impact of Fairtrade and organic certification on household income of smallholder coffee farmers in the Jinotega Municipality of Nicaragua. Using a sample of 233 coffee farming households and employing endogenous switching regression model and propensity score matching method, the results found that Fairtrade and organic certification standards have different effects on the certified farmers; while Fairtrade farmers had experienced yield gains, organic farmers had the price advantage. However, the overall impact of these certification standards on the total household income is found to be statistically not significant. While some of the Fairtrade-certified cooperatives have used the social premium in creating community-level infrastructure, there is a need for more investment. The major constraint the organic-certified farmers face is lack of availability of adequate organic inputs such as manures and organic herbicides.