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.     

Effect of NOx Control Processes on Mercury Speciation in Utility Flue Gas

Abstract

The speciation of Hg in coal-fired flue gas can be important in determining the ultimate Hg emissions as well as potential control options for the utility. The effects of NO_x control processes, such as selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR), on Hg speciation are not well understood but may impact emissions of Hg. EPRI has investigated the reactions of Hg in flue gas at conditions expected for some NO_x control processes. This paper describes the methodology used to investigate these reactions in actual flue gas at several power plants. Results have indicated that some commercial SCR catalysts are capable of oxidizing elemental Hg in flue gas obtained from the inlets of SCR or air heater units. Results are affected by various flue gas and operating parameters. The effect of flue gas composition, including the presence of NH₃, has been evaluated. The influence of NH₃ on fly ash Hg reactions also is being investigated.     

Contamination and bioaccumulation of benzotriazole ultraviolet stabilizers in fish from Manila Bay, the Philippines using an ultra-fast liquid chromatography-tandem mass spectrometry

Methyl methacrylate (MMA) is grafted on multiwalled carbon nanotubes (MWCNTs) by using N₂ plasma technique. The MMA grafted MWCNTs (MWCNT-g-pMMA) are characterized by using Raman spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, thermo gravimetric analysis-differential thermal analysis (TGA-DTA), and potentiometric acid-base titration method. The application of MWCNT-g-pMMA in the removal of 4,4′-dichlorinated biphenyl (4,4′-DCB) from large volumes of aqueous solutions is investigated under ambient conditions. The results indicate that the adsorption of 4,4′-DCB on MWCNT-g-pMMA is much higher than that of 4,4′-DCB on MWCNTs, and the adsorbed 4,4′-DCB is difficult to be thermally decomposed from MWCNT-g-pMMA according to the TGA-DTA analysis. MWCNT-g-pMMA are suitable materials in the preconcentration and immobilization of polychlorinated biphenyls (PCBs) from large volumes of aqueous solutions in environmental pollution cleanup.     

Contribution of In‐Channel Processes to Sediment Yield of an Urbanizing Watershed1

Abstract: A study was conducted between September 2003 and September 2006 to obtain baseline sediment inventories and monitor sediment transport and storage along a 3.7 km length of the channel of Valley Creek within Valley Forge National Historical Park, Pennsylvania. Valley Creek is a tributary of the Schuylkill River and drains an urbanizing 60.6 km² watershed that currently has 18% impervious land cover. Numerous field methods were employed to measure the suspended sediment yield, longitudinal profile, cross‐sections, banklines, and particle size distribution of the streambed. Suspended sediment yield for the watershed was measured at a USGS gage located just upstream of the park boundary between July 2004 and July 2005, the period corresponding to field surveys of bank erosion and channel change. The estimated suspended sediment yield of 95.7 t/km²/year is representative of a year with unusually high discharge, including a storm event that produced a peak of 78 m³/s, the second highest discharge on record for the USGS gage. Based on the median annual streamflow for the 24 years of record at the USGS gage from 1983 to 2006, the median annual sediment yield is estimated to be closer to 34 t/km²/year, considerably lower than median and mean values for other sites within the region. The mass of silt, clay, and fine sand derived from bank erosion along the 3.7 km study reach during the field survey period accounts for an estimated 2,340 t, equivalent to about 43% of the suspended sediment load. The mass of fine sediment stored in the bed along the study reach was estimated at 1,500 t, with about 330 t of net erosion during the study period. Although bank erosion appears to be a potentially dominant source of sediment by comparison with annual suspended sediment load, bed sediment storage and potential for remobilization is of the same order of magnitude as the mass of sediment derived from bank erosion.