7,304 research outputs found

    Properties of Heavy B Hadrons

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    We review recent measurements of heavy B hadron states including masses and lifetimes of the Bc meson as well as excited B states (B**, Bs**). We discuss properties of the Bs meson such as lifetime, lifetime difference delta_Gamma/Gamma and CP violation in Bs -> J/Psi Phi decays. We also summarize new measurements of the masses and lifetimes of bottom baryons including the Lambda_b baryon, the Sigma_b baryon states as well as the Xi_b and Omega_b baryons.Comment: Plenary talk at ICHEP08, Philadelphia, USA, July 2008. 15 pages with 10 figures and 1 table. Fixed typo

    Mesenchymal stem cells as therapeutic candidates for halting the progression of diabetic nephropathy

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    Mesenchymal stem cells (MSCs) possess pleiotropic properties that include immunomodulation, inhibition of apoptosis, fibrosis and oxidative stress, secretion of trophic factors, and enhancement of angiogenesis. These properties provide a broad spectrum for their potential in a wide range of injuries and diseases, including diabetic nephropathy (DN). MSCs are characterized by adherence to plastic, expression of the surface molecules CD73, CD90, and CD105 in the absence of CD34, CD45, HLA-DR, and CD14 or CD11b and CD79a or CD19 surface molecules, and multidifferentiation capacity in vitro. MSCs can be derived from many tissue sources, consistent with their broad, possibly ubiquitous distribution. This article reviews the existing literature and knowledge of MSC therapy in DN, as well as the most appropriate rodent models to verify the therapeutic potential of MSCs in DN setting. Some preclinical relevant studies are highlighted and new perspectives of combined therapies for decreasing DN progression are discussed. Hence, improved comprehension and interpretation of experimental data will accelerate the progress towards clinical trials that should assess the feasibility and safety of this therapeutic approach in humans. Therefore, MSC-based therapies may bring substantial benefit for patients suffering from DN.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo/Sao Paulo Research Foundation) [2013/19560-6]CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/National Counsel of Technological and Scientific Development) [456959/2013-0]EFSD (European Foundation for the Study of Diabetes)Sociedade Beneficente Albert Einstein, Albert Einstein Hospital, 05652 São Paulo, SP, Brazil[University of São Paulo, 01246 São Paulo, SP, BrazilFederal University of São Paulo, 04023 São Paulo, SP, BrazilFederal University of São Paulo, 04023 São Paulo, SP, BrazilFAPESP: 2013/19560-6CNPq: 456959/2013-0Web of Scienc

    Operator Product Expansion for Exclusive Decays: B^+ ->Ds^+ e+e- and B^+ -> Ds^{*+} e+e-

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    The decays B+Ds,d+e+eB^+\to D_{s,d}^+e^+e^- and B+Ds,d+e+eB^+\to D_{s,d}^{*+}e^+e^- proceed through a weak and an electromagnetic interaction. This is a typical ``long distance'' process, usually difficult to compute systematically. We propose that over a large fraction of phase space a combination of an operator product and heavy quark expansions effectively turns this process into one in which the weak and electromagnetic interactions occur through a local operator. Moreover, we use heavy quark spin symmetry to relate all the local operators that appear in leading order of the operator expansion to two basic ones. We use this operator expansion to estimate the decay rates for B+Ds,d()+e+eB^+\to D_{s,d}^{(*)+}e^+e^-.Comment: 4 pages, 1 figure, Latex, published version in PR

    N-Acetylcysteine Serves as Substrate of 3-Mercaptopyruvate Sulfurtransferase and Stimulates Sulfide Metabolism in Colon Cancer Cells

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    Hydrogen sulfide (H2S) is an endogenously produced signaling molecule. The enzymes 3-mercaptopyruvate sulfurtransferase (MST), partly localized in mitochondria, and the inner mitochondrial membrane-associated sulfide:quinone oxidoreductase (SQR), besides being respectively involved in the synthesis and catabolism of H2S, generate sulfane sulfur species such as persulfides and polysulfides, currently recognized as mediating some of the H2S biological effects. Reprogramming of H2S metabolism was reported to support cellular proliferation and energy metabolism in cancer cells. As oxidative stress is a cancer hallmark and N-acetylcysteine (NAC) was recently suggested to act as an antioxidant by increasing intracellular levels of sulfane sulfur species, here we evaluated the effect of prolonged exposure to NAC on the H2S metabolism of SW480 colon cancer cells. Cells exposed to NAC for 24 h displayed increased expression and activity of MST and SQR. Furthermore, NAC was shown to: (i) persist at detectable levels inside the cells exposed to the drug for up to 24 h and (ii) sustain H2S synthesis by human MST more effectively than cysteine, as shown working on the isolated recombinant enzyme. We conclude that prolonged exposure of colon cancer cells to NAC stimulates H2S metabolism and that NAC can serve as a substrate for human MST

    Augmented reality for innovation: Education and analysis of the glacial retreat of the Peruvian Andean snow-capped mountains

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    Mountain glaciers are considered great reservoirs of water, and their importance lies in the fact that many of our ecosystems and numerous communities depend on them; Peru has one of the largest extensions of Andean snow-capped mountains, which have been affected by the decline in their glacier coverage and that is warned, will disappear due to environmental conditions and alterations in the current global temperature. This problem has increased due to ignorance, misinformation, indifference, and lack of solidarity on the part of the population who favors this discouraging situation. Taking advantage of the current technological immersion, in which we live, the development of a mobile application was proposed as a pedagogical resource to raise awareness among educational institutions about the glacial retreat of the Peruvian Andean snow-capped mountains, showing the current situation of some of the snow-capped mountains of the Andes that have suffered a greater impact, implementing augmented reality technology to obtain an interactive link. To provide greater detail of the situation, previous studies were carried out on glacial retreats in two Peruvian snow-capped mountains over the last 40 years, where it was found that, of the snow-capped mountains considered, Chicon had a decrease of 32.5% of its glacier cover, and Pumahuanca had a decrease of 56.9%. Such results are exposed within the application to provide realistic data on the glacial conditions of both Peruvian snow-capped mountains, as well as the consequences and conservation techniques to mitigate and cope with deglaciation. Taking into consideration that environmental education from an early age turns out to be key to forming an informed and participatory society about climate change

    Determination of the Jet Energy Scale at the Collider Detector at Fermilab

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    A precise determination of the energy scale of jets at the Collider Detector at Fermilab at the Tevatron ppˉp\bar{p} collider is described. Jets are used in many analyses to estimate the energies of partons resulting from the underlying physics process. Several correction factors are developed to estimate the original parton energy from the observed jet energy in the calorimeter. The jet energy response is compared between data and Monte Carlo simulation for various physics processes, and systematic uncertainties on the jet energy scale are determined. For jets with transverse momenta above 50 GeV the jet energy scale is determined with a 3% systematic uncertainty

    "The Public Health Contribution of Sentiment Analysis of Monkeypox Tweets to Detect Polarities Using the CNN-LSTM Model"

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    "Monkeypox is a rare disease caused by the monkeypox virus. This disease was considered eradicated in 1980 and was believed to affect rodents and not humans. However, recent years have seen a massive outbreak of monkeypox in humans, setting off worldwide alerts from health agencies. As of September 2022, the number of confirmed cases in Peru had reached 1964. Although most monkeypox patients have been discharged, we cannot neglect the monitoring of the population with respect to the monkeypox virus. Lately, the population has started to express their feelings and opinions through social media, specifically Twitter, as it is the most used social medium and is an ideal space to gather what people think about the monkeypox virus. The information imparted through this medium can be in different formats, such as text, videos, images, audio, etc. The objective of this work is to analyze the positive, negative, and neutral feelings of people who publish their opinions on Twitter with the hashtag #Monkeypox. To find out what people think about this disease, a hybrid-based model architecture built on CNN and LSTM was used to determine the prediction accuracy. The prediction result obtained from the total monkeypox data was 83% accurate. Other performance metrics were also used to evaluate the model, such as specificity, recall level, and F1 score, representing 99%, 85%, and 88%, respectively. The results also showed the polarity of feelings through the CNN-LSTM confusion matrix, where 45.42% of people expressed neither positive nor negative opinions, while 19.45% expressed negative and fearful feelings about this infectious disease. The results of this work contribute to raising public awareness about the monkeypox virus.

    B Physics at the Tevatron: Run II and Beyond

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    This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.Comment: 583 pages. Further information on the workshops, including transparencies, can be found at the workshop's homepage: http://www-theory.lbl.gov/Brun2/. The report is also available in 2-up http://www-theory.lbl.gov/Brun2/report/report2.ps.gz or chapter-by-chapter http://www-theory.lbl.gov/Brun2/report

    The Semileptonic Decays Dπ(ρ)eνD\to \pi(\rho) e \nu and Bπ(ρ)eνB\to \pi (\rho) e \nu from QCD Sum Rules

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    We investigate the semileptonic decays of B and D mesons into π\pi and ρ\rho mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the ρ\rho meson and the shape of the lepton spectrum. For the total decay rates we find Γ(Bˉ0π+eνˉ)=(5.1±1.1)Vub21012s1\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}, Γ(D0πe+ν)=(8.0±1.7)Vcd21010s1\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}, Γ(Bˉ0ρ+eνˉ)=(1.2±0.4)Vub21013s1\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}} and Γ(D0ρe+ν)=(2.4±0.7)Vcd2109s1\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}.Comment: 23 pages, 12 figures included as uu-encoded file, needs REVTEX, TUM--T31--39/9
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