2,315 research outputs found

    Unbound states in 12^{12}C populated by γ\gamma-decay of the (Jπ,T)=(2+,1)(J^{\pi},T) = (2^+,1) 16.11 MeV state

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    The reaction 11B+p^{11}\textrm{B}+p has been used to populate the (Jπ,T)=(2+,1)(J^\pi,T) = (2^+,1) state at an excitation energy of 16.11 MeV in 12^{12}C. γ\gamma-decay to unbound states in 12^{12}C are identified from analysis of the decay of the populated daughter states. Due to a new technique, γ\gamma-decay to the 10.8 MeV 1^- state is observed for the first time, and transitions to the 9.64 MeV (3^-) and 12.71 MeV (1+^+) are confirmed. Unresolved transitions to natural parity strength at 10 MeV and 11.5-13 MeV are also observed. For all transitions partial widths are deducedComment: Corrected small typographical errors and added more details on data analysi

    Supertertiary protein structure affects an allosteric network

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    The notion that protein function is allosterically regulated by structural or dynamic changes in proteins has been extensively investigated in several protein domains in isolation. In particular, PDZ domains have represented a paradigm for these studies, despite providing conflicting results. Furthermore, it is still unknown how the association between protein domains in supramodules, consitituting so-called supertertiary structures, affects allosteric networks. Here, we experimentally mapped the allosteric network in a PDZ:ligand complex, both in isolation and in the context of a supramodular structure, and show that allosteric networks in a PDZ domain are highly dependent on the supertertiary structure in which they are present. This striking sensitivity of allosteric networks to the presence of adjacent protein domains is likely a common property of supertertiary structures in proteins. Our findings have general implications for prediction of allosteric networks from primary and tertiary structures and for quantitative descriptions of allostery

    Seeking allosteric networks in PDZ domains

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    Ever since Ranganathan and coworkers subjected the covariation of amino acid residues in the postsynaptic density-95/Discs large/Zonula occludens 1 (PDZ) domain family to a statistical correl- ation analysis, PDZ domains have represented a paradigmatic family to explore single domain protein allostery. Nevertheless, several theoretical and experimental studies in the past two dec- ades have contributed contradicting results with regard to structural localization of the allosteric networks, or even questioned their actual existence in PDZ domains. In this review, we first describe theoretical and experimental approaches that were used to probe the energetic network (s) in PDZ domains. We then compare the proposed networks for two well-studied PDZ domains namely the third PDZ domain from PSD-95 and the second PDZ domain from PTP-BL. Our analysis highlights the contradiction between the different methods and calls for additional work to better understand these allosteric phenomena

    Initial results from the Caltech/DRSI balloon-borne isotope experiment

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    The Caltech/DSRI balloonborne High Energy Isotope Spectrometer Telescope (HEIST) was flown successfully from Palestine, Texas on 14 May, 1984. The experiment was designed to measure cosmic ray isotopic abundances from neon through iron, with incident particle energies from approx. 1.5 to 2.2 GeV/nucleon depending on the element. During approximately 38 hours at float altitude, 100,000 events were recorded with Z or = 6 and incident energies approx. 1.5 GeV/nucleon. We present results from the ongoing data analysis associated with both the preflight Bevalac calibration and the flight data

    A Cerenkov - ΔE/ΔX Experiment for Measuring Cosmic-Ray Isotopes from Neon Through Iron

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    A ballon-borne cosmic-ray experiment has been constructed to measure cosmic-ray isotope masses, It employs a pair of Cerenkov counters and a NaI scintillator stack to determine changes in ΔE in energy and Δγ in Lorentz factor for a traversing or stopping particle. Mass M = ΔE/Δγ. Mass resolution better than 0.3 a.m.u. is expected for incident elements from neon through iron, with incident Lorentz gammas ranging from 2.4 to 3.1, depending on the element. Using data obtained at the Berkeley Bevalac, the mass resolution ∂M ≈ 2 a.m.u., measured for ^(55)Mn ions with incident γ = 2.5

    The Nordic maintenance care program: what are the indications for maintenance care in patients with low back pain? A survey of the members of the Danish Chiropractors' Association

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    <p>Abstract</p> <p>Background</p> <p>Maintenance care (MC) is relatively commonly used among chiropractors. However, factual information is needed on its indications for use.</p> <p>Objectives</p> <p>This study had two objectives: 1) to describe which role patients' past history and treatment outcome play in chiropractors' decision to use MC in patients with low back pain, 2) to investigate if the chiropractors' clinical/educational background has an effect on the frequency of using MC and their indications for use of MC.</p> <p>Method</p> <p>An anonymous questionnaire was sent to all 413 chiropractors practising in Denmark. Its main part consisted of 3 sets of 4 questions relating to one basic case of low back pain. For each case, the chiropractors were asked if they would use MC as they self-defined the term (no/perhaps/yes). There were questions also on gender, age, educational and clinical background, and on the number of MC patients seen by these chiropractors. Their decision to recommend MC was reported. Associations between the demographic variables and 1) the frequency of MC-use and 2) their indications for use of MC were tested through multivariate analysis.</p> <p>Results</p> <p>The response rate was 72%. Non-indications for MC were: 1) a good outcome combined with no previous events, or 2) a past history of LBP and gradual worsening with treatment. Indications for MC were a good outcome combined with a previous history of low back pain between once a month and once a year. The mean proportion of MC patients per week were 22% (SD 19), ranging from 0% to 100%. The use of MC was highest among experienced chiropractors, those who were educated in North America, and clinic owners. However, in Denmark most chiropractors graduated before 1999, are educated abroad, whereas most chiropractors thereafter are educated in Denmark. Therefore, we cannot conclude whether this difference relates to education or years of experience. There were no associations detected between demographic variables and the indications for MC.</p> <p>Conclusions</p> <p>There is relatively high consensus on when MC should and should not be used. A history of prior low back pain combined with a positive response to treatment encourages the use of MC, whereas no previous history of back pain or a worsening of symptoms discourages the use of MC. There seems to be a difference in the proportional use of MC between chiropractors with more experience educated in North America and those with less experience educated in Denmark.</p

    An International Study of the Ability and Cost-Effectiveness of Advertising Methods to Facilitate Study Participant Self-Enrolment Into a Pilot Pharmacovigilance Study During Early Pregnancy

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    Knowledge of the fetal effects of maternal medication use in pregnancy is often inadequate and current pregnancy pharmacovigilance (PV) surveillance methods have important limitations. Patient self-reporting may be able to mitigate some of these limitations, providing an adequately sized study sample can be recruited.To compare the ability and cost-effectiveness of several direct-to-participant advertising methods for the recruitment of pregnant participants into a study of self-reported gestational exposures and pregnancy outcomes.The Pharmacoepidemiological Research on Outcomes of Therapeutics by a European Consortium (PROTECT) pregnancy study is a non-interventional, prospective pilot study of self-reported medication use and obstetric outcomes provided by a cohort of pregnant women that was conducted in Denmark, the Netherlands, Poland, and the United Kingdom. Direct-to-participant advertisements were provided via websites, emails, leaflets, television, and social media platforms.Over a 70-week recruitment period direct-to-participant advertisements engaged 43,234 individuals with the study website or telephone system; 4.78% (2065/43,234) of which were successfully enrolled and provided study data. Of these 90.4% (1867/2065) were recruited via paid advertising methods, 23.0% (475/2065) of whom were in the first trimester of pregnancy. The overall costs per active recruited participant were lowest for email (€23.24) and website (€24.41) advertisements and highest for leaflet (€83.14) and television (€100.89). Website adverts were substantially superior in their ability to recruit participants during their first trimester of pregnancy (317/668, 47.5%) in comparison with other advertising methods (P<.001). However, we identified international variations in both the cost-effectiveness of the various advertisement methods used and in their ability to recruit participants in early pregnancy.Recruitment of a pregnant cohort using direct-to-participant advertisement methods is feasible, but the total costs incurred are not insubstantial. Future research is needed to identify advertising strategies capable of recruiting large numbers of demographically representative pregnant women, preferentially in early pregnancy
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