1,476 research outputs found
An AC electric trap for ground-state molecules
We here report on the realization of an electrodynamic trap, capable of
trapping neutral atoms and molecules in both low-field and high-field seeking
states. Confinement in three dimensions is achieved by switching between two
electric field configurations that have a saddle-point at the center of the
trap, i.e., by alternating a focusing and a defocusing force in each direction.
AC trapping of 15ND3 molecules is experimentally demonstrated, and the
stability of the trap is studied as a function of the switching frequency. A 1
mK sample of 15ND3 molecules in the high-field seeking component of the
|J,K>=|1,1> level, the ground-state of para-ammonia, is trapped in a volume of
about 1 mm^3
Dissociable Processes of Cognitive Control during Error and Non-Error Conflicts: A Study of the Stop Signal Task
Conflict detection and subsequent behavioral adjustment are critical to daily life, and how this process is controlled has been increasingly of interest. A medial cortical region which includes the anterior cingulate cortex (ACC) has been theorized to act as a conflict detector that can direct prefrontal activity for behavioral adjustments. This conflict monitoring hypothesis was supported by many imaging studies of the Stroop task, with a focus on non-error processes. Here we sought to examine whether this circuit could be generalized to the stop signal task (SST), another behavioral paradigm widely used to study cognitive control. In particular, with a procedure to elicit errors in the SST, we examined whether error and non-error control were mediated by the same pathways.In functional magnetic resonance imaging of 60 healthy adults, we demonstrated that the medial cortical activity during stop success (SS) as compared to go success (G) trials is correlated with increased prefrontal activity in post-stop SS as compared to post-go SS trials, though this correlation was not specific to the medial cortical region. Furthermore, thalamic and insular rather than medial cortical activation during stop error (SE) as compared to G trials correlated with increased prefrontal activity in post-stop SS as compared to post-go SS trials.Taken together, these new findings challenge a specific role of the ACC and support distinct pathways for error and non-error conflict processing in cognitive control
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High-temperature Oxidation of an Alumina-Coated Ni-Base Alloy
Alumina coatings were applied to Ni-20Cr (wt%) using combustion chemical vapor deposition (combustion CVD). Combustion CVD is an open air deposition technique performed in a flame. The oxidation kinetics of coated and uncoated specimens were measured by isothermal oxidation tests carried out in pure flowing air at temperatures of 800, 900, 1,000 and 1,100 C. The alumina coatings reduced the oxidation kinetics at all temperatures. The morphologies and compositions of the alumina coatings were characterized by transmission and scanning electron microscopy, energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy
Young people today: news media, policy and youth justice
The new sociology of childhood sees children as competent social agents with important contributions to make. And yet the phase of childhood is fraught with tensions and contradictions. Public policies are required, not only to protect children, but also to control them and regulate their behaviour. For children and young people in the UK, youth justice has become increasingly punitive. At the same time, social policies have focused more on children's inclusion and participation. In this interplay of conflict and contradictions, the role the media play is critical in contributing to the moral panic about childhood and youth. In this article, we consider media representations of âantisocialâ children and young people and how this belies a moral response to the nature of contemporary childhood. We conclude by considering how a rights-based approach might help redress the moralised politics of childhood representations in the media
Studies on Soil Transmitted Helminthic Infection Among Coal Miners in Sawah Lunto, West Sumatra
Prevalensi cacing Perut diantara karyawan tambang batu bara Ombilin Sawah Lunto adalah 91,2 persen, 39,8 persen dan 13,persen masing-masing untuk cacing tambang, Ascaris lumbricoides dan Trichuris trichiura. Sebagian besar karyawan tambang bati bara ini menderita anemia (hanya 13,3 persen diantara mereka yang mempunyai kadar haemoglobin dalam batas-batas normal). Ukuran persen diantara mereka yang mempunyai kadar haemoglobin dalam batas-batas normal). Ukuran Unthropometrik menunjukkan bahwa hanya 62,5 persen berat badak untuk tinggi badan karyawan tambang ini termasuk kategori 90 persen atau lebih Standard nasional yang diusulkan. Percobaan pengobatan dengan menggunakan tetramisole (ascaridil) menunjukkan bahwa obat ini memberikan hasil yang memuaskan hanya untuk infestasi A. lumbricoides
Discovery of a New Pulsar Wind Nebula in the Large Magellanic Cloud
We present new high-resolution radio and X-ray observations of the supernova
remnant (SNR) B0453-685 in the Large Magellanic Cloud, carried out with the
Australia Telescope Compact Array and the Chandra X-ray Observatory
respectively. Embedded in the SNR shell is a compact central nebula producing
both flat-spectrum polarized radio emission and non-thermal X-rays; we identify
this source as a pulsar wind nebula (PWN) powered by an unseen central neutron
star. We present a new approach by which the properties of a SNR and PWN can be
used to infer upper limits on the initial spin period and surface magnetic
field of the unseen pulsar, and conclude that this star was an initial rapid
rotator with current properties similar to those of the Vela pulsar. As is the
case for other similarly-aged sources, there is currently an interaction taking
place between the PWN and the SNR's reverse shock.Comment: 4 pages of text plus 2 embedded EPS figures. Minor changes following
referee's report. ApJ Letters, in pres
Sensitivity to a possible variation of the proton-to-electron mass ratio torsion-wagging-rotation transitions in methylamine CH3NH2
9 x 10(-6) is deduced
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A new interpretation of total column BrO during Arctic spring
Emission of bromine from sea-salt aerosol, frost flowers, ice leads, and snow results in the nearly complete removal of surface ozone during Arctic spring. Regions of enhanced total column BrO observed by satellites have traditionally been associated with these emissions. However, airborne measurements of BrO and O3 within the convective boundary layer (CBL) during the ARCTAS and ARCPAC field campaigns at times bear little relation to enhanced column BrO. We show that the locations of numerous satellite BrO âhotspotsâ during Arctic spring are consistent with observations of total column ozone and tropopause height, suggesting a stratospheric origin to these regions of elevated BrO. Tropospheric enhancements of BrO large enough to affect the column abundance are also observed, with important contributions originating from above the CBL. Closure of the budget for total column BrO, albeit with significant uncertainty, is achieved by summing observed tropospheric partial columns with calculated stratospheric partial columns provided that natural, short-lived biogenic bromocarbons supply between 5 and 10 ppt of bromine to the Arctic lowermost stratosphere. Proper understanding of bromine and its effects on atmospheric composition requires accurate treatment of geographic variations in column BrO originating from both the stratosphere and troposphere
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