Perturbation theory for localized solutions of sine-Gordon equation: decay of a breather and pinning by microresistor

We develop a perturbation theory that describes bound states of solitons localized in a confined area. External forces and influence of inhomogeneities are taken into account as perturbations to exact solutions of the sine-Gordon equation. We have investigated two special cases of fluxon trapped by a microresistor and decay of a breather under dissipation. Also, we have carried out numerical simulations with dissipative sine-Gordon equation and made comparison with the McLaughlin-Scott theory. Significant distinction between the McLaughlin-Scott calculation for a breather decay and our numerical result indicates that the history dependence of the breather evolution can not be neglected even for small damping parameter

Energy funneling in a bent chain of Morse oscillators with long-range coupling

A bent chain of coupled Morse oscillators with long-range dispersive interaction is considered. Moving localized excitations may be trapped in the bending region. Thus chain geometry acts like an impurity. An energy funneling effect is observed in the case of random initial conditions.Comment: 6 pages, 12 figures. Submitted to Physical Review E, Oct. 13, 200

Instabilities and Bifurcations of Nonlinear Impurity Modes

We study the structure and stability of nonlinear impurity modes in the discrete nonlinear Schr{\"o}dinger equation with a single on-site nonlinear impurity emphasizing the effects of interplay between discreteness, nonlinearity and disorder. We show how the interaction of a nonlinear localized mode (a discrete soliton or discrete breather) with a repulsive impurity generates a family of stationary states near the impurity site, as well as examine both theoretical and numerical criteria for the transition between different localized states via a cascade of bifurcations.Comment: 8 pages, 8 figures, Phys. Rev. E in pres

Perturbed soliton excitations in DNA molecular chain

We study nonlinear dynamics of a periodic inhomogeneous DNA double helical chain under dynamic plane-base rotator model by considering angular rotation of bases in a plane normal to the helical axis. The dynamics is governed by a perturbed sine-Gordon equation. The perturbed soliton solution is obtained using a multiple scale soliton perturbation theory. The perturbed kink-antikink solitons represent formation of open state configuration with fluctuation in DNA.Comment: 20 Pages, 5 figure

Phenomenological Inquiry

B1 - Research Book Chapter

Administration Rates of the Tdap Vaccine in Obstetric Patients

BACKGROUND: Infants younger than 6 months of age are at high risk for contracting pertussis because of not being fully vaccinated. The Advisory Committee on Immunization Practices (ACIP) recommends vaccinating all pregnant women with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) between 27 and 36 weeks to offer passive immunity to the infant to help protect them until they are able to receive the full pertussis series. OBJECTIVE: To assess and compare compliance with the 2013 ACIP recommendation of vaccinating pregnant women with Tdap at 27 to 36 weeks\u27 gestation in 2 obstetric clinics. METHODS: This cross-sectional, retrospective chart review evaluated Tdap vaccine compliance in a random sample of obstetric patients from October 2013 to September 2014. The primary outcome evaluated the proportion of patients who received Tdap between 27 and 36 weeks\u27 gestation. Secondary outcomes included the proportion of patients who received Tdap at any point in pregnancy and within 30 days postpartum. RESULTS: The charts of 573 patients were reviewed, and 237 met inclusion criteria. For the primary outcome, 142 patients (59.9%) received the Tdap vaccine. Overall, 156 patients (65.8%) received Tdap at some point during the pregnancy. Factors associated with receiving the Tdap vaccination were insurance status, prenatal care risk level and site of prenatal care, receipt of the influenza vaccine, and preterm labor in the current pregnancy. CONCLUSION: The Tdap vaccine rate was 65.8%, with 59.9% of patients receiving the vaccine within the recommended ACIP timeframe. Further education, improvements in documentation, and chart reminders are needed to enhance administration