Analysis of the semileptonic Λb→Λℓ+ℓ−\Lambda_b\rightarrow \Lambda \ell^+ \ell^- transition in topcolor-assisted technicolor (TC2) model

We comparatively analyze the flavor changing neutral current process of the $\Lambda_b \rightarrow \Lambda \ell^+ \ell^-$ in the standard model as well as topcolor-assisted technicolor model using the form factors calculated via light cone QCD sum rules in full theory. In particular, we calculate the decay width, branching ratio and lepton forward-backward asymmetry related to this decay channel. We compare the results of the topcolor-assisted technicolor model with those of the standard model and debate how the results of the topcolor-assisted technicolor model depart from the standard model predictions. We also compare our results on the differential branching ratio with recent experimental data provided by CDF and LHCb Collaborations.Comment: 29 Pages, 16 Figures and 8 Table

Effect of Compression Wood on Leaching and Fixation of CCA-C Treated Red Pine

In this study, we investigated the effect of compression wood on the release rate of chromium, copper, and arsenic elements from red pine (Pinus resinosa Ait.) and the rate of fixation of hexavalent chromium in the wood. Wood blocks from red pine, some containing compression wood and some with normal wood, were treated with a 1.0% CCA-C solution and then allowed to fix at 23°C ± 2 (74°F ± 4) for 0, 6, 24, 48, 96, 192, and 336 h. After each fixation period, sets of blocks removed from the conditioning room were subjected to 336 h of leaching. The percentage of hexavalent chromium reduced to the trivalent state was determined for solution pressed from matched sets of blocks. The blocks containing compression wood released significantly less chromium and copper elements. For chromium, the biggest effect was seen after the 192- and 336-h fixation periods. In the normal wood blocks fixed for 336 h, the average chromium release rate after 6 h of leaching was almost five times greater than that of the compression wood blocks. Copper and arsenic release was also affected by compression wood, but for these two elements, the effect diminished during the later stages of fixation. A higher percentage of hexavalent chromium was reduced to trivalent chromium in compression wood compared with that in normal wood after most fixation periods, and this difference was significant after 0, 48, 96, and 192 h

Archaea catalyze iron-dependent anaerobic oxidation of methane

Anaerobic oxidation of methane (AOM) is crucial for controlling the emission of this potent greenhouse gas to the atmosphere. Nitrite-, nitrate-, and sulfate-dependent methane oxidation is well-documented, but AOM coupled to the reduction of oxidized metals has so far been demonstrated only in environmental samples. Here, using a freshwater enrichment culture, we show that archaea of the order Methanosarcinales, related to “Candidatus Methanoperedens nitroreducens,” couple the reduction of environmentally relevant forms of Fe^(3+) and Mn^(4+) to the oxidation of methane. We obtained an enrichment culture of these archaea under anaerobic, nitrate-reducing conditions with a continuous supply of methane. Via batch incubations using [^(13)C]methane, we demonstrated that soluble ferric iron (Fe^(3+), as Fe-citrate) and nanoparticulate forms of Fe^(3+) and Mn^(4+) supported methane-oxidizing activity. CO_2 and ferrous iron (Fe^(2+)) were produced in stoichiometric amounts. Our study connects the previous finding of iron-dependent AOM to microorganisms detected in numerous habitats worldwide. Consequently, it enables a better understanding of the interaction between the biogeochemical cycles of iron and methane

Query complexity of Boolean functions on the middle slice of the cube

We study the query complexity of slices of Boolean functions. Among other results we show that there exists a Boolean function for which we need to query all but 7 input bits to compute its value, even if we know beforehand that the number of 0's and 1's in the input are the same, i.e. when our input is from the middle slice. This answers a question of Byramji. Our proof is non-constructive, but we also propose a concrete candidate function that might have the above property. Our results are related to certain natural discrepancy type questions that -- somewhat surprisingly -- have not been studied before.Comment: 10 page

Self-trapping of strong electromagnetic beams in relativistic plasmas

Interaction of an intense electromagnetic (EM) beam with hot relativistic plasma is investigated. It is shown that the thermal pressure brings about a fundamental change in the dynamics - localized, high amplitude, EM field structures, not accessible to a cold (but relativisic) plasma, can now be formed under well- defined conditions. Examples of the trapping of EM beams in self-guiding regimes to form stable 2D solitonic structures in a pure e-p plasma are worked out.Comment: 9 pages, 6 figure

Localized structures of electromagnetic waves in hot electron-positronplasmas

The dynamics of relativistically strong electromagnetic (EM) wave propagation in hot electron-positron plasma is investigated. The possibility of finding localized stationary structures of EM waves is explored. It is shown that under certain conditions the EM wave forms a stable localized soliton-like structures where plasma is completely expelled from the region of EM field location.Comment: 14 pages, LaTeX, 1 figure can be obtained upon request through email to [email protected]

Extensive psoriasis induced by pegylated interferon: a case report

This paper describes the clinical course of a patient with chronic hepatitis C, genotype 2a/2c, previously treated with Interferon α2b and subsequently with Lymphoblastoid Interferon without any response, and also without any cutaneous side effects. The patient, a 50 year-old woman, was re-treated with Pegylated α2b Interferon plus Ribavirin for 24 weeks, at standard doses; during the third month of therapy she developed a mild form of psoriasis. However, encouraged by the progressive improvement of her transaminase levels and viral load decrease, the patient asked to continue the treatment; she normalized the transaminase levels during the fourth month and showed HCV-RNA negativity during the fifth month of therapy. Nevertheless, the psoriasis become worse, extending to over 75% of her body. Therapy was completed after sixth months. A month after the therapy was ceased, the patient's psoriasis receded spontaneously and completely. During the subsequent four years the patient did not experience any recurrence of either the hepatic disease or the psoriasis

Interactions of anaerobic ammonium oxidizers and sulfide-oxidizing bacteria in a substrate-limited model system mimicking the marine environment

In nature anaerobic ammonium oxidation (anammox) and denitrification processes convert fixed nitrogen to gaseous nitrogen compounds, which are then released to the atmosphere. While anammox bacteria produce N2 from ammonium and nitrite, in the denitrification process nitrate and nitrite are converted to N2 and the greenhouse gas nitrous oxide (N2O). Furthermore, nitrite needed by the anammox bacteria can be supplied by nitrate reduction to nitrite. Consequently, the interplay between nitrogen-transforming microorganisms control the amount of harmless N2 or the greenhouse gas N2O released to the atmosphere. Therefore, it is important to understand the interactions of these microorganisms in the natural environment, where dynamic conditions result in fluctuating substrate concentrations. Here, we studied the interactions between the sulfide-oxidizing denitrifier Sedimenticola selenatireducens and the anammox bacterium Scalindua brodae in a bioreactor mimicking the marine environment by creating sulfide, ammonium and nitrate limitation in distinct operational phases. Through a microbial interaction, Se. selenatireducens reduced nitrate to nitrite, which together with the supplied ammonium was converted to N2 by Sc. Brodae. Using comparative transcriptomics, we determined that Sc. Brodae and Se. selenatireducens had significant responses to ammonium and nitrate limitation, respectively, indicating that the activities of these microorganisms are regulated by different nitrogen compounds

Comparative analysis of the semileptonic Λb→Λℓ+ℓ−\Lambda_b \rightarrow \Lambda \ell^+ \ell^- transition in SM and different SUSY scenarios using form factors from full QCD

We work out the semileptonic $\Lambda_b\rightarrow \Lambda \ell^+ \ell^-$ transition in standard as well as different supersymmetric models. In particular, considering the parametrization of the matrix elements entered the low energy effective Hamiltonian in terms of form factors in full QCD, we calculate the amplitude and differential decay rate responsible for this decay channel in supersymmetric models. We then use the form factors calculated via light cone QCD sum rules in full theory to analyze the differential branching ratio and lepton forward-backward asymmetry of this decay channel in different supersymmetric models and compare the obtained results with those of the standard model. We also discuss how the results of different supersymmetric models deviate from the standard model predictions and which SUSY scenarios are favored.Comment: 23 Pages, 8 Figures and 11 Table