On the Solution of the Monge-Ampere Equation ZxxZyy - Z²xy= f (x, y) with Quadratic Right Side

For the Monge{Ampere equation ZxxZyy-Z²xy = b₂₀x²+b₁₁xy+b₀₂y²+b₀₀ we consider the question on the existence of a solution Z(x, y) in the class of polynomials such that Z = Z(x, y) is a graph of a convex surface. If Z is a polynomial of odd degree, then the solution does not exist. If Z is a polynomial of 4-th degree and 4b₂₀b₀₂ - b₁₁² > 0, then the solution also does not exist. If 4b₂₀b₀₂ - b₁₁² = 0, then we have solutions

Investigating harbor porpoise (Phocoena phocoena) population differentiation using RAD-tag genotyping by sequencing

The population status of the harbor porpoise ( Phocoena phocoena ) in the Baltic Sea and adjacent regions is still not fully resolved. Here, we present a pilot study using the double digest restriction-site associated DNA sequencing (ddRAD-seq) genotyping- by -sequencing method on specimens from the Baltic Sea, eastern North Sea, Spain and the Black Sea. From a single Illumina lane and a set of 49 individuals, w e obtained around 6000 SNPs. We used these markers to estimate population structure and differentiation, and identified splits between porpoises from the North Sea and the Baltic, and within regions in the Baltic Sea (between the Belt Sea and the Inner Baltic Sea). The SNP analysis confirms population structure elucidated by previous mtDNA/microsatellite studies. We demonstrate the feasibility of SNP analysis on opportunistically sampled cetacean samples, with varying DNA quality, for population diversity and divergence analysis

Status and Trends-Nature

Humanity is now a dominant influence on nature worldwide (well established) {2 .2 .5, 2 .2 .7}, with many impacts having accelerated rapidly in the 20th century (well established) {2 .2 .5 .2} . Humanity has influenced nature significantly since prehistory, both positively (e.g., development of agrobiodiversity) and negatively (e.g., extinction of megafauna and flightless island birds) (well established) {2.2.4, 2.2.5.1}; but nature ? including species, their genes and populations, communities of interacting populations, ecological and evolutionary processes, and the landscapes and ecosystems in which they live is now declining rapidly and many facets of nature have already been much reduced (well established) {2.2.5}, supporting suggestions that Earth has entered the AnthropoceneFil: Purvis, Andy. The Natural History Museum; Reino UnidoFil: Molnár, Zsolt. Center for Ecological Research; HungríaFil: Obura, David. CORDIO East Africa; KeniaFil: Ichii, Kazuhito. Chiba University; JapónFil: Willis, Katherine. University of Oxford; Reino UnidoFil: Chettri, Nakul. International Centre for Integrated Mountain Development; IndiaFil: Dulloo, Mohammad. Mauritian Wildlife Foundation; MauritaniaFil: Hendry, Andrew. McGill University; CanadáFil: Gabrielyan, B.. Scientific Center of Zoology and Hydroecology; ArmeniaFil: Gutt, Julian. Alfred Wegener Institute; AlemaniaFil: Jacob, Ute. Helmholtz Institute for Functional Marine Biodiversity; AlemaniaFil: Keskin, Emre. Ankara University; TurquíaFil: Niamir, Aidin. Senckenberg Biodiversity and Climate Research Centre; DinamarcaFil: Öztürk, Bayram. Istanbul Unversity; TurquíaFil: Salimov, Rashad A.. Institute of Botany; AzerbaiyánFil: Jaureguiberry, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Measurements of Thermal Conductivity Variations with Temperature for the Organic Analog of the Nonmetal–Nonmetal System: Urea–4-Bromo-2-Nitroaniline

Thermal conductivity variations with temperature for solid phases in the Urea (U)-[X] mol pct 4-bromo-2-nitroaniline (BNA) system (X = 0, 2, 45, 89.9, and 100) were measured using the radial heat flow method. From graphs of thermal conductivity variations with temperature, the thermal conductivities of the solid phases at their melting temperature and temperature coefficients for the U-[X] mol pct BNA system (X = 0, 2, 45, 89.9, and 100) were found to be 0.26, 0.55, 0.46, 0.38, and 0.23 W/Km and 0.007781, 0.005552, 0.002058, 0.002188, and 0.002811 K-1, respectively. The ratios of thermal conductivity of the liquid phase to thermal conductivity of the solid phase in the U-[X] mol pct BNA system (X = 0, 2, 45, 89.9, and 100) were also measured to be 0.30, 0.44, 0.46, 0.49, and 0.51, respectively, with a Bridgman-type directional solidification apparatus at their melting temperature. (C) The Minerals, Metals & Materials Society and ASM International 201