Blooms of cyanobacteria in a temperate Australian lagoon system post and prior to European settlement

Blooms of noxious N2 fixing cyanobacteria such as Nodularia spumigena are a recurring problem in some estuaries; however, the historic occurrence of such blooms in unclear in many cases. Here we report the results of a palaeoecological study on a temperate Australian lagoon system (the Gippsland Lakes) where we used stable isotopes and pigment biomarkers in dated cores as proxies for eutrophication and blooms of cyanobacteria. Pigment proxies show a clear signal, with an increase in cyanobacterial pigments (echinenone, canthaxanthin and zeaxanthin) in the period coinciding with recent blooms. Another excursion in these proxies was observed prior to the opening of an artificial entrance to the lakes in 1889, which markedly increased the salinity of the Gippsland Lakes. A coincident increase in the sediment organic-carbon content in the period prior to the opening of the artificial entrance suggests that the bottom waters of the lakes were more stratified and hypoxic, which would have led to an increase in the recycling of phosphorus. After the opening of the artificial entrance, there was a  ∼  60-year period with low values for the cyanobacterial proxies as well as a low sediment organic-carbon content suggesting a period of low bloom activity associated with the increased salinity of the lakes. During the 1940s, the current period of re-eutrophication commenced, as indicated by a steadily increasing sediment organic-carbon content and cyanobacterial pigments. We suggest that increasing nitrogen inputs from the catchment led to the return of hypoxia and increased phosphorus release from the sediment, which drove the re-emergence of cyanobacterial blooms

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

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

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 mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Search for anomalous couplings in boosted WW/WZ -> l nu q(q)over-bar production in proton-proton collisions at root s=8TeV

Peer reviewe

Coding of sound motion in the rat auditory cortex

Recent studies have suggested a previously undiscovered aspect of primary auditory cortex function. Investigators now believe that in addition to coding for the location of sound sources in the external environment, auditory cortex may also encode information relevant to sound source motion. In this study, responses of single neurons in the left primary auditory cortex of rats were studied while simultaneously presenting binaural sounds which simulated sound source motion. The stimuli simulated a pure-tone source moving in several radial and circular dimensions in the front contralateral field of space. The results indicated that many neurons in the primary auditory cortex responded in a preferential manner to different directions of sound motion. Moreover, it appeared that cells with similar directional selectivity were organized in columns perpendicular to the surface of the cortex. There was also evidence that the speed of sound motion affected the responses of the cells. Additional stimuli were presented in an effort to identify which aspects of the motion stimulus were most critical for the neural response to sound motion. Among the cells most responsive to motion, radial movement was more likely to elicit an excitatory response than circular motion. There was also evidence that binaural responses in the cortex were more complex than those seen in the superior olivary complex, suggesting that the responses in the cortex are the result of integrated processing of time and intensity information from the olive, or, alternatively, that the responses at the cortex may arise from processing pathways independent of the superior olivary complex

Coding of sound motion in the rat auditory cortex

Recent studies have suggested a previously undiscovered aspect of primary auditory cortex function. Investigators now believe that in addition to coding for the location of sound sources in the external environment, auditory cortex may also encode information relevant to sound source motion. In this study, responses of single neurons in the left primary auditory cortex of rats were studied while simultaneously presenting binaural sounds which simulated sound source motion. The stimuli simulated a pure-tone source moving in several radial and circular dimensions in the front contralateral field of space. The results indicated that many neurons in the primary auditory cortex responded in a preferential manner to different directions of sound motion. Moreover, it appeared that cells with similar directional selectivity were organized in columns perpendicular to the surface of the cortex. There was also evidence that the speed of sound motion affected the responses of the cells. Additional stimuli were presented in an effort to identify which aspects of the motion stimulus were most critical for the neural response to sound motion. Among the cells most responsive to motion, radial movement was more likely to elicit an excitatory response than circular motion. There was also evidence that binaural responses in the cortex were more complex than those seen in the superior olivary complex, suggesting that the responses in the cortex are the result of integrated processing of time and intensity information from the olive, or, alternatively, that the responses at the cortex may arise from processing pathways independent of the superior olivary complex