60 research outputs found

    The breaking of the flavour permutational symmetry: Mass textures and the CKM matrix

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    Different ansaetze for the breaking of the flavour permutational symmetry according to S(3)L X S(3)R in S(2)L X S(2) give different Hermitian mass matrices of the same modified Fritzsch type, which differ in the symmetry breaking pattern. In this work we obtain a clear and precise indication on the preferred symmetry breaking scheme from a fit of the predicted theoretical Vckm to the experimentally determined absolute values of the elements of the CKM matrix. The preferred scheme leads to simple mass textures and allows us to compute the CKM mixing matrix, the Jarlskog invariant J, and the three inner angles of the unitarity triangle in terms of four quark mass ratios and only one free parameter: the CP violating phase Phi. Excellent agreement with the experimentally determined absolute values of the entries in the CKM matrix is obtained for Phi = 90 deg. The corresponding computed values of the Jarlskog invariant and the inner angles are J = 3.00 X 10^-5, alpha= 84 deg, beta= 24 deg and gamma =72 deg in very good agreement with current data on CP violation in the neutral kaon-antikaon system and oscillations in the B-Bbar system.Comment: 21 pages, 1 fig. Content enlarged, references added and typos corrected. To be published in Phys Rev

    The CP violating phase \delta_{13} and the quark mixing angles \theta_{13}, \theta_{23} and \theta_{12} from flavour permutational symmetry breaking

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    The phase equivalence of the theoretical mixing matrix Vth{\bf V}^{th} derived from the breaking of the flavour permutational symmetry and the standard parametrization VPDG{\bf V}^{PDG} advocated by the Particle Data Group is explicitly exhibited. From here, we derive exact explicit expressions for the three mixing angles θ12\theta_{12}, θ13\theta_{13}, θ23\theta_{23}, and the CP violating phase δ13\delta_{13} in terms of the quark mass ratios (mu/mt,mc/mt,md/mb,ms/mb)(m_{u}/m_{t}, m_{c}/m_{t}, m_{d}/m_{b}, m_{s}/m_{b}) and the parameters Z1/2Z^{*1/2} and Φ\Phi^* characterizing the preferred symmetry breaking pattern. The computed values for the CP violating phase and the mixing angles are: δ13=75\delta^*_{13}=75^\circ, sinθ12=0.221\sin\theta^*_{12}=0.221, sinθ13=0.0034\sin\theta^*_{13}=0.0034, and sinθ23=0.040\sin\theta^*_{23}=0.040, which coincide almost exactly with the central values of the experimentally determined quantities.Comment: 25 pages, we added an estimation of a reasonable range of values for the quark mass ratios and the corresponding quark mixing matrix elements. Accepted in Phys. Rev. D, 01 April 200

    Phytoremediation Potential of <em>Chrysopogon zizanioides</em> for Toxic Elements in Contaminated Matrices

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    Many researchers have demonstrated the advantages of plants in the phytoremediation of soils and waters contaminated with heavy metals, herbicides, pesticides, leachates, etc. The unique morphological characteristics of Chrysopogon zizanioides, commonly known as vetiver, make it a hyperaccumulator of metals; its roots can store high concentrations of heavy metals such as As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn, and it has thus been successfully used in the field of environmental protection. This chapter presents the importance of vetiver, its characterization, and its potential use as phytoremediation potential for toxic elements in contaminated matrices

    Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD) : an observational study in Mexico

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    Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD. Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test. Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn’s disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments. Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD

    Gut dysbiosis and clinical phases of pancolitis in patients with ulcerative colitis

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    Ulcerative colitis (UC) is a frequent type of inflammatory bowel disease, characterized by periods of remission and exacerbation. Gut dysbiosis may influence pathophysiology and clinical response in UC. The purpose of this study was to evaluate whether gut microbiota is related to the active and remission phases of pancolitis in patients with UC as well as in healthy participants. Fecal samples were obtained from 18 patients with UC and clinical‐endoscopic evidenced pancolitis (active phase n = 9 and remission phase n = 9), as well as 15 healthy participants. After fecal DNA extraction, the 16S rRNA gene was amplified and sequenced (Illumina MiSeq), operational taxonomic units were analyzed with the QIIME software. Gut microbiota composition revealed a higher abundance of the phyla Proteobacteria and Fusobacteria in active pancolitis, as compared with remission and healthy participants. Likewise, a marked abundance of the genus Bilophila and Fusobacteria were present in active pancolitis, whereas a higher abundance of Faecalibacterium characterized both remission and healthy participants. LEfSe analysis showed that the genus Roseburia and Faecalibacterium were enriched in remission pancolitis, and genera Bilophila and Fusobacterium were enriched in active pancolitis. The relative abundance of Fecalibacterium and Roseburia showed a higher correlation with fecal calprotectin, while Bilophila and Fusobacterium showed AUCs (area under the curve) of 0.917 and 0.988 for active vs. remission pancolitis. The results of our study highlight the relation of gut dysbiosis with clinically relevant phases of pancolitis in patients with UC. Particularly, Fecalibacterium, Roseburia, Bilophila, and Fusobacterium were identified as genera highly related to the different clinical phases of pancolitis

    Perturbation of the Dimer Interface of Triosephosphate Isomerase and its Effect on Trypanosoma cruzi

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    Most of the enzymes of parasites have their counterpart in the host. Throughout evolution, the three-dimensional architecture of enzymes and their catalytic sites are highly conserved. Thus, identifying molecules that act exclusively on the active sites of the enzymes from parasites is a difficult task. However, it is documented that the majority of enzymes consist of various subunits, and that conservation in the interface of the subunits is lower than in the catalytic site. Indeed, we found that there are significant differences in the interface between the two subunits of triosephosphate isomerase from Homo sapiens and Trypanosoma cruzi (TcTIM), which causes Chagas disease in the American continent. In the search for agents that specifically inhibit TcTIM, we found that 2,2′-dithioaniline (DTDA) is far more effective in inactivating TcTIM than the human enzyme, and that its detrimental effect is due to perturbation of the dimer interface. Remarkably, DTDA prevented the growth of Escherichia coli cells that had TcTIM instead of their own TIM and killed T. cruzi epimastigotes in culture. Thus, this study highlights a new approach base of targeting molecular interfaces of dimers

    Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls

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    Sixty beef bulls with a body weight (BW) of 314.79 16.2 kg were used to evaluate the effects of zilpaterol hydrochloride (ZH) and zinc methionine (ZM) on growth performance and carcass characteristics. The experimental design was a randomized complete block, with a factorial 22 arrangement of treatments (ZH: 0 and 0.15 mg kg 1 BW; ZM: 0 and 80 mg kg 1 dry matter). The ZH increased (PB0.05) the final BW, average daily gain, feed conversion, carcass yield and longissimus dorsi area. Bulls fed ZH plus ZM had less (PB0.01) backfat thickness and intramuscular fat (IMF) compared with those fed ZH or ZM alone. The ZH increased (PB0.02) the meat crude protein content and cooking loss. It is therefore concluded that ZH increases growth performance, carcass yield, longissimus dorsi area, and meat crude protein. The interaction of ZM and ZH did not present additional advantages. The reason for the reduction in backfat thickness and IMF by ZH plus ZM is unclear, and implies that our knowledge of b-agonistic adrenergic substances and their interactions with minerals is incomplete
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