36 research outputs found
Diffractive Excitation of Heavy Flavors: Leading Twist Mechanisms
Diffractive production of heavy flavors is calculated within the light-cone
dipole approach. Novel leading twist mechanisms are proposed, which involve
both short and long transverse distances inside the incoming hadron.
Nevertheless, the diffractive cross section turns out to be sensitive to the
primordial transverse momenta of projectile gluons, rather than to the hadronic
size. Our calculations agree with the available data for diffractive production
of charm and beauty, and with the observed weak variation of the
diffraction-to-inclusive cross section ratios as function of the hard scale.Comment: Latex, 19 pages, 12 figures. A short commenting on previously done
computations is adde
Quantum-mechanical description of in-medium fragmentation
We present a quantum-mechanical description of quark-hadron fragmentation in
a nuclear environment. It employs the path-integral formulation of quantum
mechanics, which takes care of all phases and interferences, and which contains
all relevant time scales, like production, coherence, formation, etc. The cross
section includes the probability of pre-hadron (colorless dipole) production
both inside and outside the medium. Moreover, it also includes inside-outside
production, which is a typical quantum-mechanical interference effect (like
twin-slit electron propagation). We observe a substantial suppression caused by
the medium, even if the pre-hadron is produced outside the medium and no energy
loss is involved. This important source of suppression is missed in the usual
energy-loss scenario interpreting the effect of jet quenching observed in heavy
ion collisions. This may be one of the reasons of a too large gluon density,
reported by such analyzes.Comment: 20 pages, 7 figure
Public participation in planning a comfortable urban environment on the example of the Arkhangelsk region
The article analyzes the experience of public participation in the planning of a comfortable urban environment. The forms of public involvement in the formation of a comfortable urban environment and their implementation are considered on the example of the Arkhangelsk region. The method of complex analysis of the theory and practice of public communications helps the article to present a qualitative as-sessment of public involvement in the improvement of the urban environment. It is shown that the existing methods of interaction between the authorities and citizens represent a one-sided process and often they are reduced to the formal fulfillment of legal requirements by municipalities. To improve the efficiency of public participation, the authors propose to develop a communicative model of urban space management based on constant interaction between municipal authorities and citizens. This model will allow establishing a dialogue between all stakeholders, which will ultimately lead to the successful implementation of the urban environmental program and improve the quality of life of citizens
Perturbative fragmentation
The Berger model of perturbative fragmentation of quarks to pions is improved
by providing an absolute normalization and keeping all terms in a (1-z)
expansion, which makes the calculation valid at all values of fractional pion
momentum z. We also replace the nonrelativistic wave function of a loosely
bound pion by the more realistic procedure of projecting to the light-cone pion
wave function, which in turn is taken from well known models. The full
calculation does not confirm the (1-z)^2 behavior of the fragmentation function
(FF) predicted in for , and only works at very large z>0.95, where it is
in reasonable agreement with phenomenological FFs. Otherwise, we observe quite
a different z-dependence which grossly underestimates data at smaller z. The
disagreement is reduced after the addition of pions from decays of light vector
mesons, but still remains considerable. The process dependent higher twist
terms are also calculated exactly and found to be important at large z and/or
pT.Comment: 10 pages, 8 figure
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594).
Conclusions:
GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation