2,758 research outputs found

    Nuclear Medium Modifications of Hadrons from Generalized Parton Distributions

    Full text link
    We study the structure of generalized parton distributions in spin 0 nuclei within a microscopic approach for nuclear dynamics. GPDs can be used on one side as tools to unravel the deep inelastic transverse structure of nuclei in terms of both transverse spatial and transverse momentum degrees of freedom. On the other, one can obtain information on GPDs themselves by observing how they become modified in the nuclear environment. We derive the structure of the nuclear deeply virtual Compton scattering tensor and generalized parton distributions at leading order in QQ in a field-theoretical framework. The nuclear generalized parton distributions are calculated using a two step process -- the convolution approach -- where the scattering process happens from a quark inside a nucleon, itself inside a nucleus, disregarding final state interactions with both the nuclear and nucleon debris. We point out that details of the nuclear long range interactions such as two-body currents, can be disregarded compared to the deep inelastic induced modifications of the bound GPDs. We show how the pattern of nuclear modifications predicted, and in particular the deviations of off-shell effects from the longitudinal convolution provide clear signals to be sought in experimental measurements. Finally, we find interesting relationships by studying Mellin moments in nuclei: in particular we predict the AA-dependence for the DD-term of GPDs within a microscopic approach, and the behavior with tt of the total momentum carried by quarks in a nucleus. The latter provides an important element for the evaluation of nuclear hadronization phenomena which are vital for interpreting current and future data at RHIC, HERMES and Jefferson Lab.Comment: 29 pages, 10 figure

    Air freight : the problems of airport restrictions : final report on the Conference of Air Cargo Industry Considerations of Airport Curfews

    Get PDF
    April 1979Conference held in Jupiter, Fla. in January 1979Includes bibliographical references (p. 36)Noise due to aircraft was considered to be a potential problem as far back as 1952, when the Doolittle Commission established by President Truman urged that a major effort be made to reduce aircraft noise. With the 'advent of the jet age in the late 1950's and the concomitant spread of suburbs towards airports in major cities such as New York, Denver, and Minneapolis-St. Paul, many more people became exposed to noise, and concern and anger intensified. Although only a small percentage (estimated at about 2-3%) of the total population of the U.S. is affected by high noise levels, these people and their representatives have been quite vocal about their dissatisfaction with noise abatement progress, even though technological advances have reduced the noise emanating from aircraft engines. As a result, the airports, the communities, and the federal government are seeking additional measures that will further diminish the noise impact of aircraft and airport operations. The dilemma is to decrease noise with the minimum economic disruptions to commerce, the community, and the aviation industry. Since very few people like to travel during the night hours (approximately 10 p.m. - 7 a.m.), and indeed very few aircraft operations take place (less than 5% of total operations at most airports), an environmentally and politically appealing option to diminish the effect of aircraft noise is to ban airplane operations during nighttime hours. However, a disproportionate number of operations at night are dedicated to cargo (about 50% of scheduled domestic all-cargo flights), and it is upon the air cargo industry and those users dependent upon nighttime flights that the major burden of a curfew would fall. The benefits of curfews are apparent; the economic penalties associated with them are not. To address this issue, the Flight Transportation Laboratory of the Massachusetts Institute of Technology hosted a week-long conference at Jupiter, Florida, in January, 1979, on the impact of airport use restrictions on air freight. This conference was sponsored by the Federal Aviation Administration and the Port Authority of New York and New Jersey. More than 70 participants, including some 50 panelists and speakers, represented various viewpoints of the air cargo industry: the users, the airlines, the airports, the communities, and various governmental agencies

    A retrospective, observational, real-world evidence study to understand the clinical and obstetric characteristics and tolerability profile of women in labor managed with camylofin dihydrochloride injection

    Get PDF
    Background: To determine the clinical and obstetric characteristics and tolerability profile of pregnant women in the active phase of labor who were managed with Camylofin dihydrochloride injection.Methods: Retrospective data of 210 full-term pregnant women in the active phase of labor who were managed with Camylofin injection doses of 50 mg, 50+25 mg and 50+50 mg were considered in the study. The comparative effectiveness of 3 doses was evaluated using independent T-test and ANOVA at 5% level of significance.Results: The overall mean maternal age was 25.4 (±4.14) years with mean gestational age of 38.8 (±1.04) weeks. In total, 77.1% (n=162) of patients needed 50 mg dose of Camylofin injection for adequate cervical dilatation, and additional doses of 25 mg or 50 mg were required in 16.7% (n=35) and 6.2% (n=13), of patients, respectively to accelerate the labor. The mean cervical dilatation rates increasing dose viz 2.8 cm/hr, 4.1 cm/hr and 2.9 cm/hr, respectively. The adverse events were 14.8% (n=23) in 50 mg arm, 34.3% (n=12) in 50+25 arm and 69.0% (n=9) in 50+50 arm. Of the total, 34 events (50.0%) were related to Camylofin dihydrochloride injection, i.e. ADRs.The means of cervical dilation rate, active phase duration and total duration of labor were statistically significant (p-value <0.001) for 50 mg versus 50+25 mg.Conclusions: The study infers Camylofin injection usage with consideration of dose escalation in the routine clinical management of labor. Both mother and neonate had shown comparable tolerability profile across the three dosage arms with minimal events

    PMH22 Economic Burden of Attention Deficit Hyperactivity Disorder in Children and Adolescents in Europe

    Get PDF

    The length of time's arrow

    Full text link
    An unresolved problem in physics is how the thermodynamic arrow of time arises from an underlying time reversible dynamics. We contribute to this issue by developing a measure of time-symmetry breaking, and by using the work fluctuation relations, we determine the time asymmetry of recent single molecule RNA unfolding experiments. We define time asymmetry as the Jensen-Shannon divergence between trajectory probability distributions of an experiment and its time-reversed conjugate. Among other interesting properties, the length of time's arrow bounds the average dissipation and determines the difficulty of accurately estimating free energy differences in nonequilibrium experiments

    Biofilm-based simultaneous nitrification, denitrification, and phosphorous uptake in wastewater by Neurospora discreta

    Get PDF
    Biological removal of nitrogen and phosphorous from wastewater conventionally involves multiple processing steps to satisfy the differing oxygen requirements of the microbial species involved. In this work, simultaneous nitrification, denitrification, and phosphorous removal from synthetic wastewater were achieved by the fungus Neurospora discreta in a single-step, biofilm-based, aerobic process. The concentrations of carbon, nitrogen, and phosphorous in the synthetic wastewater were systematically varied to investigate their effects on nutrient removal rates and biofilm properties. Biofilm growth was significantly (p < 0.05) affected by carbon and nitrogen, but not by phosphorous concentration. Scanning electron microscopy revealed the effects of nutrients on biofilm microstructure, which in turn correlated with nutrient removal efficiencies. The carbohydrate and protein content in the biofilm matrix decreased with increasing carbon and nitrogen concentrations but increased with increasing phosphorous concentration in the wastewater. High removal efficiencies of carbon (96%), ammonium (86%), nitrate (100%), and phosphorus (82%) were achieved under varying nutrient conditions. Interestingly, decreasing the phosphorus concentration increased the nitrification and denitrification rates, and decreasing the nitrogen concentration increased the phosphorus removal rates significantly (p < 0.05). Correlations between biofilm properties and nutrient removal rates were also evaluated in this study

    PKPD relationships and dose rationale in analgesic drug development : towards the prediction of target engagement

    Get PDF
    Chronic pain is a significant health problem that greatly impacts the quality of life of individual patients and imparts high costs to society. Despite intense research effort and progress in our understanding of the mechanistic and molecular basis of pain, chronic pain remains a significant clinical problem that has few effective therapies Throughout the various chapters we have highlighted some important conceptual and experimental flaws in the way that pain signalling and pharmacological activity are characterised and translated across species and disease conditions. The common denominator of the work presented here is the requirement for accurate characterisation of exposure-response relationships, without which the dose rationale for the progression of a molecule cannot justified, whether drugs are aimed at symptomatic relief, disease modification or prophylaxis. In addition to a comprehensive review of the mechanisms underlying pain signalling and symptoms, the work developed here focuses on three different aspects of research underpinning the use of pharmacokinetic-pharmacodynamic relationships. First, we have explored the requirements for the characterisation of behavioural measures of pain during the early screening of candidate molecules, shedding light onto the shortcomings of experimental protocols commonly used in preclinical research. Then we introduced the prerequisites for the parameterisation of pain behaviour to ensure accurate translation of the pharmacological properties across species as well as for bridging across different phases of development. Lastly, an attempt was made to model clinical response in chronic inflammatory pain and to establish correlations between symptom improvement and the underlying pharmacological effects using biomarkers. In addition our work showed how clinical trial simulations can be used as a design tool, enabling the evaluation of a variety of scenarios that disentangle the contribution of pharmacology from the confounding effects of placebo and disease dynamics.UBL - phd migration 201
    • …
    corecore