3,142 research outputs found

    Capacity and tendency: A neuroscientific framework for the study of emotion regulation.

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    It is widely accepted that the ability to effectively regulate one's emotions is a cornerstone of physical and mental health. As such, it should come as no surprise that the number of neuroimaging studies focused on emotion regulation and associated processes has increased exponentially in the past decade. To date, neuroimaging research on this topic has examined two distinct but complementary features of emotion regulation - the capacity to effectively utilize a strategy to regulate emotion and to a lesser extent, the tendency to choose to regulate. However, theoretical accounts of emotion regulation have only recently begun to distinguish capacity from tendency. In the present review, we provide a novel framework for conceptualizing these two intertwined, yet distinct, facets of emotion regulation. First we characterize brain regions that support emotion generation and are thus targeted by emotion regulation. Next, we synthesize findings from the dozens of neuroimaging studies that have examined emotion regulation capacity, focusing in particular on the most commonly studied emotion regulation strategy - reappraisal. Finally, we discuss emerging neuroimaging research examining state and trait regulatory tendencies. We conclude by integrating findings from neuroimaging research on emotion regulation capacity and tendency and suggest ways that this integrated model can inform basic and translational neuroscientific research on emotion regulation

    Magnetic buoyancy instabilities in the presence of magnetic flux pumping at the base of the solar convection zone

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    We perform idealized numerical simulations of magnetic buoyancy instabilities in three dimensions, solving the equations of compressible magnetohydrodynamics in a model of the solar tachocline. In particular, we study the effects of including a highly simplified model of magnetic flux pumping in an upper layer (‘the convection zone’) on magnetic buoyancy instabilities in a lower layer (‘the upper parts of the radiative interior – including the tachocline’), to study these competing flux transport mechanisms at the base of the convection zone. The results of the inclusion of this effect in numerical simulations of the buoyancy instability of both a preconceived magnetic slab and a shear-generated magnetic layer are presented. In the former, we find that if we are in the regime that the downward pumping velocity is comparable with the Alfvén speed of the magnetic layer, magnetic flux pumping is able to hold back the bulk of the magnetic field, with only small pockets of strong field able to rise into the upper layer. In simulations in which the magnetic layer is generated by shear, we find that the shear velocity is not necessarily required to exceed that of the pumping (therefore the kinetic energy of the shear is not required to exceed that of the overlying convection) for strong localized pockets of magnetic field to be produced which can rise into the upper layer. This is because magnetic flux pumping acts to store the field below the interface, allowing it to be amplified both by the shear and by vortical fluid motions, until pockets of field can achieve sufficient strength to rise into the upper layer. In addition, we find that the interface between the two layers is a natural location for the production of strong vertical gradients in the magnetic field. If these gradients are sufficiently strong to allow the development of magnetic buoyancy instabilities, strong shear is not necessarily required to drive them (cf. previous work by Vasil & Brummell). We find that the addition of magnetic flux pumping appears to be able to assist shear-driven magnetic buoyancy in producing strong flux concentrations that can rise up into the convection zone from the radiative interior

    Collisional depolarization of state selected (J,M J ) BaO A 1Σ+ measured by optical–optical double resonance

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    The optical–optical double resonance (OODR) technique is used to investigate the change in magnetic quantum number (M) a state selected molecule undergoes on collision with other molecules. A first linearly polarized dye laser prepares A  1Σ+BaO(v = 1) in the J = 1, M = 0 sublevel. The extent of collisional transfer to other M sublevels of both J = 1 and J = 2 is then probed by a second polarized dye laser which induces fluorescence from the C  1Σ+ state. Elastic collisions (ΔJ = 0) between BaO (A  1Σ+) and CO2 are observed to change M from 0 to ±1 leaving J unchanged. The total elasticM‐changing cross section is σΔM CO2 = 8.4±2.4 Å2. Inelastic collisions (ΔJ = +1’ which transfer molecules to j = 2 also cause M changes. with both Ar and CO2 as collision partners. M, the s p a c e‐f i x e d projection of J, is found to be neither conserved nor randomized. Quantum atom–diatom collision models with quantization axis along the relative velocity vector are considered. Transition amplitudes in this system are evaluated using the l‐dominant and CS approximations

    Effects of a Caffeine-Containing Transdermal Energy Patch on Aerobic and Anaerobic Exercise Performance

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    The use of caffeine-containing (74-mg) energy patches (EnP) offers a novel mode of caffeine delivery that may alleviate stomach discomfort associated with oral caffeine use. The purpose of this study was to use four separate tests to evaluate the effects of EnP use on aerobic and anaerobic exercise performance. Three separate moderately active college-aged sample populations performed either 1) cycle time-to-exhaustion, 2) Wingate (WIN), or 3) repeated sprints and one repetition maximum bench press using EnP and placebo patches (PlP). No statistical differences were found between EnP and PlP for all dependent variables (p \u3e 0.05) except for WIN peak power, which showed a statistically significant decrease (p = 0.04). The dose of caffeine topically applied via an EnP may not have been enough to elicit an ergogenic effect on exercise performance. A dose greater than 74-mg caffeine may be needed to produce an ergogenic effect. Further research is needed to investigate the delivery kinetics of transdermal caffeine in large dosages along with blood caffeine concentrations during and after exercise

    Alpha effect due to buoyancy instability of a magnetic layer

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    A strong toroidal field can exist in form of a magnetic layer in the overshoot region below the solar convection zone. This motivates a more detailed study of the magnetic buoyancy instability with rotation. We calculate the alpha effect due to helical motions caused by a disintegrating magnetic layer in a rotating density-stratified system with angular velocity Omega making an angle theta with the vertical. We also study the dependence of the alpha effect on theta and the strength of the initial magnetic field. We carry out three-dimensional hydromagnetic simulations in Cartesian geometry. A turbulent EMF due to the correlations of the small scale velocity and magnetic field is generated. We use the test-field method to calculate the transport coefficients of the inhomogeneous turbulence produced by the layer. We show that the growth rate of the instability and the twist of the magnetic field vary monotonically with the ratio of thermal conductivity to magnetic diffusivity. The resulting alpha effect is inhomogeneous and increases with the strength of the initial magnetic field. It is thus an example of an "anti-quenched" alpha effect. The alpha effect is nonlocal, requiring around 8--16 Fourier modes to reconstruct the actual EMF based on the actual mean field.Comment: 14 pages, 19 figures 3 tables (submitted to A & A

    “What if There's Something Wrong with Her?”‐How Biomedical Technologies Contribute to Epistemic Injustice in Healthcare

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    While there is a steadily growing literature on epistemic injustice in healthcare, there are few discussions of the role that biomedical technologies play in harming patients in their capacity as knowers. Through an analysis of newborn and pediatric genetic and genomic sequencing technologies (GSTs), I argue that biomedical technologies can lead to epistemic injustice through two primary pathways: epistemic capture and value partitioning. I close by discussing the larger ethical and political context of critical analyses of GSTs and their broader implications for just and equitable healthcare delivery

    Degradation of 23S rRNA in Azithromycin-Treated Ribonuclease Mutants of \u3cem\u3eEscherichia coli\u3c/em\u3e.

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    Azithromycin, a macrolide antibiotic, specifically binds to the 50S ribosomal subunit of bacterial ribosomes and inhibits translation. Azithromycin also prevents 50S ribosomal subunit assembly by binding to a 50S ribosomal subunit precursor particle. When exposed to azithromycin, several ribonucleases in wild-type Escherichia coli cells degrade antibiotic-bound 50S precursor particles. Presumably, cells expressing one or more mutated ribonucleases will degrade the antibiotic-bound precursor less efficiently, resulting in increased sensitivity to the antibiotic. To test this, eight ribonucleaseûdeficient strains of Escherichia coli were grown in the presence or absence of azithromycin. Cell viability, growth rates, and protein synthesis rates were measured. Degradation of 23S rRNA was examined by hybridization with a 23S specific probe. Ribonuclease II and polynucleotide phosphorylase mutants demonstrated hypersensitivity to the antibiotic and showed a greater extent of 23S rRNA accumulation, suggesting that these two ribonucleases are important for 23S rRNA turnover in azithromycin-treated Escherichia coli
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