14 research outputs found

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Improved Measurement of Branching Fractions for pipi Transitions among Upsilon(nS)States

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    Using samples of (5.93 +/- 0.10) x 10^6 Upsilon(3S) decays and (9.11 +/- 0.14) x 10^6 Upsilon(2S) decays collected with the CLEO detector, we report improved measurements of the branching fractions for the following five transitions: B(Upsilon(3S)-->Upsilon(1S) pi^+ pi^-) = (4.46 +/- 0.01 +/- 0.13)%, B(Upsilon(2S)-->Upsilon(1S) pi^+ pi^-) = (18.02 +/- 0.02 +/- 0.61)%, B(Upsilon(3S)-->Upsilon(1S) pi^0 pi^0) = (2.24 +/- 0.09 +/- 0.11)%, B(Upsilon(2S)-->Upsilon(1S) pi^0 pi^0) = (8.43 +/- 0.16 +/- 0.42)% and B(Upsilon(3S)-->Upsilon(2S) pi^0 pi^0) = (1.82 +/- 0.09 +/- 0.12)%. In each case the first uncertainty reported is statistical, while the second is systematic.Comment: 11 pages, available at http://www.lns.cornell.edu/public/CLNS/, Accepted for Publication in Phys. Rev.

    Enzymatic and transport studies in cholesterol-fed Guinea Pigs using Intestinal Brush Border Membrane Vesicles

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    The intestinal absorptive and digestive functions using the brush border membrane (BBM) vesicles were evaluated in guinea pigs receiving cholesterol-supplemented diet for 12 weeks. The Na+-gradient-dependent transport of D-glucose (p < 0.001), L-alanine and L-phenylalanine (p < 0.01) was decreased significantly the BBM of cholesterol-fed animals. The maximal velocity (Vmax) value of the sucrase and leucine aminopeptidase was decreased without any change in the affinity constant (Km) value, demonstrating that the enzyme contents were reduced in response to cholesterol-rich diet. However, both the Km and Vmax values of the alkaline phosphatase decreased markedly, suggesting that a new enzyme of increased substrate affinity had been formed due to intestinal adaptation of cholesterol load in diet. The present study demonstrated that cholesterol feeding caused a significant alteration in nutrients absorption, membrane enzymes and chemical composition of the small intestine

    Mapping binding sites for the PDE4D5 cAMP-specific phosphodiesterase to the N- and C-domains of beta-arrestin using spot-immobilized peptide arrays

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    Beta2-ARs (beta2-adrenoceptors) become desensitized rapidly upon recruitment of cytosolic beta-arrestin. PDE4D5 (family 4 cAMP-specific phosphodiesterase, subfamily D, isoform 5) can be recruited in complex with beta-arrestin, whereupon it regulates PKA (cAMP-dependent protein kinase) phosphorylation of the beta2-AR. In the present study, we have used novel technology, employing a library of overlapping peptides (25-mers) immobilized on cellulose membranes that scan the entire sequence of beta-arrestin 2, to define the interaction sites on beta-arrestin 2 for binding of PDE4D5 and the cognate long isoform, PDE4D3. We have identified a binding site in the beta-arrestin 2 N-domain for the common PDE4D catalytic unit and two regions in the beta-arrestin 2 C-domain that confer specificity for PDE4D5 binding. Alanine-scanning peptide array analysis of the N-domain binding region identified severely reduced interaction with PDE4D5 upon R26A substitution, and reduced interaction upon either K18A or T20A substitution. Similar analysis of the beta-arrestin 2 C-domain identified Arg286 and Asp291, together with the Leu215-His220 region, as being important for binding PDE4D5, but not PDE4D3. Transfection with wild-type beta-arrestin 2 profoundly decreased isoprenaline-stimulated PKA phosphorylation of the beta2-AR in MEFs (mouse embryo fibroblasts) lacking both beta-arrestin 1 and beta-arrestin 2. This effect was negated using either the R26A or the R286A mutant form of beta-arrestin 2 or a mutant with substitution of an alanine cassette for Leu215-His220, which showed little or no PDE4D5 binding, but was still recruited to the beta2-AR upon isoprenaline challenge. These data show that the interaction of PDE4D5 with both the N- and C-domains of beta-arrestin 2 are essential for beta2-AR regulation

    Comparison Of Western Motivation Theories With Islamic Method

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    This article presents the excellence methodology of al-Targhib and al-Tarhib, according to the Qur'an against the Western motivation theory. The privileges mentioned in the Quran and al-Hadith, as well as practiced by the Companions in delivering the message of God, led by the Messenger's. This effort is the medium to those involved in missionary Islamiyya

    Supplementary Material for: Diagnosis of Inherited Epidermolysis Bullosa in Resource-Limited Settings: Immunohistochemistry Revisited

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    <p><b><i>Background:</i></b> Immunofluorescence (IFM) antigen mapping is the most commonly used technique to diagnose and differentiate epidermolysis bullosa (EB). In India, IFM is limited to few research laboratories and is not readily available, making the diagnosis largely clinical and often inaccurate. <b><i>Ob</i></b><b><i> jective of the Study:</i></b> To examine the diagnostic usefulness of immunohistochemistry (IHC) as compared to IFM in resource-limited settings. <b><i>Methods:</i></b> Forty-four consecutive EB patients were included in this study. IHC and IFM were performed on 7-µm frozen tissue sections using standard laboratory protocols with a limited panel of antibodies. The kappa coefficient of agreement was calculated with genetic analysis as the gold standard. <b><i>Results:</i></b> IFM and IHC accurately identified the subtype of EB in 80.9% (<i>p</i> < 0.001) of the cases, when a clear blister cavity was evident on biopsy. The sensitivities and specificities of IHC and IFM for diagnosing EB simplex, junctional EB, and dystrophic EB were 100, 100, and 60% and 82.4, 100, and 100%, respectively. IHC was equally effective (<i>p</i> < 0.001) in establishing the type of EB as IFM. <b><i>Conclusions:</i></b> IHC staining and its interpretation were simple and comparable to IFM. IHC had an advantage of showing subtle changes in the epidermal architecture that could not be appreciated on IFM and hence can be considered useful in resource-limited settings.</p
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