5,512 research outputs found
Modulation of calcium and potassium currents by lamotrigine
Actions of the new antiepileptic drug lamotrigine (LTG) were characterized using extracellular and whole cell patch clamp recordings from rat CAI and CA3 pyramidal cells in vitro. The results suggest that LTG, beside its previously described effect on the fast sodium inward current, also modulates - presumably voltage-gated - calcium currents and the transient potassium outward current ID. These may be effective mechanisms to inhibit pathological excitation in epilepsy and may be of potential benefit in treating: underlying cellular disturbances in bipolar disorder
Coherent versus incoherent excitation dynamics in dissipative many-body Rydberg systems
We study the impact of dephasing on the excitation dynamics of a cloud of
ultracold two-level Rydberg atoms for both resonant and off-resonant laser
excitation, using the wave function Monte Carlo (MCWF) technique. We find that
while for resonant laser driving, dephasing mainly leads to an increase of the
Rydberg population and a decrease of the Mandel Q parameter, at off-resonant
driving strong dephasing toggles between direct excitation of pairs of atoms
and subsequent excitation of single atoms, respectively. These two excitation
mechanisms can be directly quantified via the pair correlation function, which
shows strong suppression of the two-photon resonance peak for strong dephasing.
Consequently, qualitatively different dynamics arise in the excitation
statistics for weak and strong dephasing in off-resonant excitation. Our
findings show that time-resolved excitation number measurements can serve as a
powerful tool to identify the dominating process in the system's excitation
dynamics.Comment: 10 pages, 10 figure
Free energy functionals for efficient phase field crystal modeling of structural phase transformations
The phase field crystal (PFC) method has emerged as a promising technique for
modeling materials with atomistic resolution on mesoscopic time scales. The
approach is numerically much more efficient than classical density functional
theory (CDFT), but its single mode free energy functional only leads to
lattices with triangular (2D) or BCC (3D) symmetries. By returning to a closer
approximation of the CDFT free energy functional, we develop a systematic
construction of two-particle direct correlation functions that allow the study
of a broad class of crystalline structures. This construction examines planar
spacings, lattice symmetries, planar atomic densities and the atomic
vibrational amplitude in the unit cell of the lattice and also provides control
parameters for temperature and anisotropic surface energies. The power of this
new approach is demonstrated by two examples of structural phase
transformations.Comment: 4 pages, 4 figure
Cognitive Abilities and Behavioral Biases
We use a simple, three-item test for cognitive abilities to investigate whether established behavioral biases that play a prominent role in behavioral economics and finance are related to cognitive abilities. We find that higher test scores on the Cognitive Reflection Test of Frederick (2005) indeed are correlated with lower incidences of the conjunction fallacy, conservatism in updating probabilities, and overconfidence. Test scores are also significantly related to subjects’ time and risk preferences. We find no influence on anchoring. However, even if biases are lower for people with higher cognitive abilities, they still remain substantial.cognitive reflection test, behavioral finance, biases, cognitive abilities
A Continuum,O(N) Monte-Carlo algorithm for charged particles
We introduce a Monte-Carlo algorithm for the simulation of charged particles
moving in the continuum. Electrostatic interactions are not instantaneous as in
conventional approaches, but are mediated by a constrained, diffusing electric
field on an interpolating lattice. We discuss the theoretical justifications of
the algorithm and show that it efficiently equilibrates model polyelectrolytes
and polar fluids. In order to reduce lattice artifacts that arise from the
interpolation of charges to the grid we implement a local, dynamic subtraction
algorithm. This dynamic scheme is completely general and can also be used with
other Coulomb codes, such as multigrid based methods
Cooling-Off in Negotiations - Does It Work?
Negotiations frequently end in conflict after one party rejects a final offer. In a large-scale internet experiment, we investigate whether a 24-hour coolingoff period leads to fewer rejections in ultimatum bargaining. We conduct a standard cash treatment and a lottery treatment, where subjects receive lottery tickets for several large prizes - emulating a high-stakes environment. In the lottery treatment, unfair offers are less frequently rejected, and cooling-off significantly reduces the rejection rate further. In the cash treatment, rejections are more frequent and remain so after cooling-off. This treatment difference is particularly pronounced for subjects with lower cognitive abilities.
Cognitive Abilities and Behavioral Biases
We use a simple, three-item test for cognitive abilities to investigate whether established behavioral biases that play a prominent role in behavioral economics and finance are related to cognitive abilities. We find that higher test scores on the Cognitive Reflection Test of Frederick (2005) indeed are correlated with lower incidences of the conjunction fallacy, conservatism in updating probabilities, and overconfidence. Test scores are also significantly related to subjects' time and risk preferences. We find no influence on anchoring. However, even if biases are lower for people with higher cognitive abilities, they still remain substantial.
Care planning for aggression management in a specialist secure mental health service:user involvement
This paper describes an audit of prevention and management of violence and aggression care plans and incident reporting forms which aimed to: (i) report the compliance rate of completion of care plans; (ii) identify the extent to which patients contribute to and agree with their care plan; (iii) describe de-escalation methods documented in care plans; and (iv) ascertain the extent to which the de-escalation methods described in the care plan are recorded as having been attempted in the event of an incident. Care plans and incident report forms were examined for all patients in men's and women's mental health care pathways who were involved in aggressive incidents between May and October 2012. In total, 539 incidents were examined, involving 147 patients and 121 care plans. There was no care plan in place at the time of 151 incidents giving a compliance rate of 72%. It was documented that 40% of patients had contributed to their care plans. Thematic analysis of de-escalation methods documented in the care plans revealed five de-escalation themes: staff interventions, interactions, space/quiet, activities and patient strategies/skills. A sixth category, coercive strategies, was also documented. Evidence of adherence to de-escalation elements of the care plan was documented in 58% of incidents. The reasons for the low compliance rate and very low documentation of patient involvement need further investigation. The inclusion of coercive strategies within de-escalation documentation suggests that some staff fundamentally misunderstand de-escalation
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