Different pathways of nitrogen and phosphorus regeneration mediated by extracellular enzymes in temperate lakes under various trophic state

Several Italian and Chinese temperate lakes with soluble reactive phosphorus concentrations &lt; 0.015 mg L-1 were studied to estimate nitrogen and phosphorus regeneration mediated by microbial decomposition and possible different mechanisms driven by prevailing oligo- or eutrophic conditions. Leucine aminopeptidase (LAP), beta-glucosidase (GLU) and alkaline phosphatase (AP), algal, and bacterial biomass were related to trophic and environmental variables. In the eutrophic lakes, high algal and particulate organic carbon concentrations stimulated bacterial respiration (&gt; 20 mu g C L-1 h(-1)) and could favor the release of inorganic phosphorus. High extracellular enzyme activities and phosphorus solubilizing bacteria abundance in sediments accelerated nutrient regeneration. In these conditions, the positive GLU-AP relationship suggested the coupling of carbon and phosphorus regeneration; an efficient phosphorus regeneration and high nitrogen levels (up to 0.067 and 0.059 mg L-1 NH4 and NO3 in Italy; 0.631 and 1.496 mg L-1 NH4 and NO3 in China) led to chlorophyll a peaks of 14.9 and 258.4 mu g L-1 in Italy and China, respectively, and a typical algal composition. Conversely, in the oligo-mesotrophic lakes, very low nitrogen levels (in Italy, 0.001 and 0.005 mg L-1 NH4 and NO3, respectively, versus 0.053 and 0.371 mg L-1 in China) induced high LAP, while low phosphorus (33.6 and 46.3 mu g L-1 total P in Italy and China, respectively) led to high AP. In these lakes, nitrogen and phosphorus regeneration were coupled, as shown by positive LAP-AP relationship; however, the nutrient demand could not be completely met without the supply from sediments, due to low enzymatic activity and phosphorus solubilizing bacteria found in this compartment.</p

Observing the Evolution of the Universe

How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass. We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey. Full list of 177 author available at http://cmbpol.uchicago.ed

Genome-wide Association Study of Alcohol Dependence

Identification of genes contributing to alcohol dependence will improve our understanding of the mechanisms underlying this disorder

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

Peer reviewe

Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

Peer reviewe

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe