The structure and bonding in ionized water clusters, (H2O)(n)(+) (n = 3–9), has been studied using the basin hopping search algorithm in combination with quantum chemical calculations. Initially candidate low energy isomers were generated using basin hopping in conjunction with density functional theory. Subsequently, the structures and energies were refined using second order Møller–Plesset pe...

A new species of freshwater sponge, Heteromeyenia barlettai sp. nov., is proposed here based on specimens discovered in a private aquarium in São Paulo, Brazil, and most likely inadvertently collected from the Paraná Basin. The present study also presents a redescription of H. insignis on the basis of the specimen reported upon by Volkmer (1963), collected from the Atlântico Sul Hydrographic Ba...

Ten new species of Hemerodromia Meigen, 1822 are described and illustrated from the Brazilian state of Amazonas: H. amazonensis sp. nov., H. breviradia sp. nov., H. cercusdilatata sp. nov., H. collini sp. nov., H. epandriocurvialis sp. nov., H. jauensis sp. nov., H. lamellata sp. nov., H. longilamellata sp. nov., H. maturaca sp. nov., H. smithi sp. nov. This is the first record of the genus fro...

Arylboron compounds have intriguing properties and are important building blocks for chemical synthesis. A family of Ir catalysts now enables the direct synthesis of arylboron compounds from aromatic hydrocarbons and boranes under "solventless" conditions. The Ir catalysts are highly selective for C-H activation and do not interfere with subsequent in situ transformations, including Pd-mediated...

We investigated the e€ect of increasing spatial and temporal resolutions on modelled distributions of snow water equivalence (SWE) and snowmelt in the Emerald Lake Watershed (ELW) of the Sierra Nevada of California, USA. We used a coupled remote sensing/distributed energy balance snowmelt model (SNODIS), and used previously validated results from a high spatial (30 m) and temporal (hourly) reso...

In order to understand spatial variations of stable isotope geochemistry in the Quruqtagh basin (northwestern China) in the aftermath of an Ediacaran glaciation, we analyzed carbonate carbon isotopes (dCcarb), carbonate oxygen isotopes (dOcarb), carbonate associated sulfate sulfur (d SCAS) and oxygen isotopes (d OCAS), and pyrite sulfur isotopes (d Spy) of a cap dolostone atop the Ediacaran Han...

Over the past eight years there has been tremendous progress in the development of Pd-catalyzed ligand-directed C H oxidation reactions to form C O, C N, C S, C halogen, and C C bonds. In marked contrast, analogous C H oxidation reactions of substrates that do not contain directing groups remain challenging. The lack of a directing group typically renders these transformations (as exemplified b...

The purpose of this study is to evaluate the progress and regional variations of crop production in Bangladesh. The secondary data were used and collected for the years 1980-81 to 2002-03 from the ‘Statistical Yearbooks of Bangladesh’, ‘Yearbook of Agricultural Statistics’ and population census of different years. The study was conducted during the period from September 2006 to February 2008. A...

Urban areas can be large emitters of air pollutants leading to negative health effects and environmental degradation. The rate of venting of these airsheds determines the pollutant loading for given emission levels, and also determines the regional impacts of the urban plume. Mexico City has approximately 20 million people living in a high altitude basin with air pollutant concentrations above ...