1,955 research outputs found
Vagal nerve stimulation therapy: what is being stimulated?
Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity
The Lived Experiences of Intended Parents During Surrogate Pregnancy and Transition to Parenthood in Relation to the United States Healthcare System.
Problem: A state of the science surrogate pregnancy manuscript revealed a dearth of research regarding intended parents of surrogate pregnancy. Not one U.S. study could be located. Intended parents are overlooked by the healthcare system during pregnancy due to the fact that that their surrogate is receiving obstetric care. Research was proposed and completed. Purpose: The aim of the research was to fill a gap by improving our understanding of intended parents lived experience during surrogate pregnancy and transition to parenthood with relation to the United States healthcare system Design: A study of phenomenology using van Manen\u27s methodology Participants: Eleven intended parents of surrogate pregnancy Setting: All interviews were conducted by telephone, with the exception of one that was done utilizing SKYPE video conferencing. x Analysis: van Manen\u27s three prong approach to analysis was completed across all transcripts, identifying common or repetitive themes. Themes were coded and hermeneutic expressions were attached for the final phase of analysis, the narrative writing. Findings: Five overarching themes were identified including Knowledge Acquisition and Preparedness; Access to the U.S. Healthcare System; Financial Risk and Exposure; Legal Complexities and Trust in Relationships. Conclusion: Findings support the development of evidence based practice guidelines for the following periods: preconception, pregnancy including labor, delivery, birth and transition to parenthood. Recommendations are for future studies related to ART and third party reproduction, as well as enhancing models of care for the intended parent during surrogate pregnancy and transition to parenthood
On the emergence of the CDM model from self-interacting Brans-Dicke theory in
We investigate whether a self-interacting Brans-Dicke theory in without
matter and with a time-dependent metric can describe, after dimensional
reduction to , the FLRW model with accelerated expansion and
non-relativistic matter. By rewriting the effective 4-dimensional theory as an
autonomous three-dimensional dynamical system and studying its critical points,
we show that the CDM cosmology cannot emerge from such a model. This
result suggests that a richer structure in may be needed to obtain the
accelerated expansion as well as the matter content of the 4-dimensional
universe.Comment: 7 pages, 7 figure
Proof that the Hydrogen-antihydrogen Molecule is Unstable
In the framework of nonrelativistic quantum mechanics we derive a necessary
condition for four Coulomb charges ,
where all masses are assumed finite, to form the stable system. The obtained
stability condition is physical and is expressed through the required minimal
ratio of Jacobi masses. In particular this provides the rigorous proof that the
hydrogen-antihydrogen molecule is unstable. This is the first result of this
sort for four particles.Comment: Submitted to Phys.Rev.Let
Dynamics of a two-level system strongly coupled to a high-frequency quantum oscillator
Recent experiments on quantum behavior in microfabricated solid-state systems
suggest tantalizing connections to quantum optics. Several of these experiments
address the prototypical problem of cavity quantum electrodynamics: a two-level
system coupled to a quantum harmonic oscillator. Such devices may allow the
exploration of parameter regimes outside the near-resonance and weak-coupling
assumptions of the ubiquitous rotating-wave approximation (RWA), necessitating
other theoretical approaches. One such approach is an adiabatic approximation
in the limit that the oscillator frequency is much larger than the
characteristic frequency of the two-level system. A derivation of the
approximation is presented and the time evolution of the two-level-system
occupation probability is calculated using both thermal- and coherent-state
initial conditions for the oscillator. Closed-form evaluation of the time
evolution in the weak-coupling limit provides insight into the differences
between the thermal- and coherent-state models. Finally, potential experimental
observations in solid-state systems, particularly the Cooper-pair
box--nanomechanical resonator system, are discussed and found to be promising.Comment: 16 pages, 11 figures; revised abstract; some text revisions; added
two figures and combined others; added references. Submitted to Phys. Rev.
Scalable Ion Trap Quantum Computing without Moving Ions
A hybrid quantum computing scheme is studied where the hybrid qubit is made
of an ion trap qubit serving as the information storage and a solid-state
charge qubit serving as the quantum processor, connected by a superconducting
cavity. In this paper, we extend our previous work [1] and study the
decoherence, coupling and scalability of the hybrid system. We present our
calculations of the decoherence of the coupled ion - charge system due to the
charge fluctuations in the solid-state system and the dissipation of the
superconducting cavity under laser radiation. A gate scheme that exploits rapid
state flips of the charge qubit to reduce decoherence by the charge noise is
designed. We also study a superconducting switch that is inserted between the
cavity and the charge qubit and provides tunable coupling between the qubits.
The scalability of the hybrid scheme is discussed together with several
potential experimental obstacles in realizing this scheme
Vagal Nerve Stimulation Therapy: What Is Being Stimulated?
Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity
Having a MHEC of a Time with SARA and State Authorization!
Session participants will hear an update on the status of SARA (State Authorization Reciprocity Agreement); learn the benefits of joining SARA and how institutions join SARA through KBOR. Representatives from Cowley College will share how they have successfully achieved approval in 49 states and three territories, with the last state in final stages of approval
Isolation and characterization of microsatellite loci from two inbreeding bark beetle species (Coccotrypes)
We developed 14 microsatellite markers in Coccotrypes carpophagus and 14 in C. dactyliperda.
These loci will be used for studying genetic structure and the level of inbreeding in
populations in the Canary Islands and Madeira. As a result of long-term inbreeding,
genetic variability is relatively low in these bark beetle species. We found one to five alleles
per locus in 29 C. carpophagus and 41 C. dactyliperda from various localities. Eleven of the
markers developed for C. carpophagus amplified in C. dactyliperda and seven of the markers
developed for C. dactyliperda amplified in C. carpophagus
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