5,149 research outputs found
The effect of thickeners and performance-enhancing powders on the application characteristics of mascara
Dose of colistin. a work in progress?
We thank Rashid and colleagues [1] and Honoré and colleagues [2] for their comments regarding our article on risk factors for acute kidney injury in pa- tients receiving colistin or other nephrotoxic antimi- crobials [3].
It is correct that we did not specifically report urine output in the text, but it was obviously included in the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria reported in Table two [3]
Administrative Law - Pending Petition for Agency Reconsideration Bars Appellate Court Jurisdiction
The effect of place of residence on access to employment : a field experiment on qualified young job applicants in Ile-de-France
Geodesic acoustic modes in a fluid model of tokamak plasma : the effects of finite beta and collisionality
Starting from the Braginskii equations, relevant for the tokamak edge region,
a complete set of nonlinear equations for the geodesic acoustic modes (GAM) has
been derived which includes collisionality, plasma beta and external sources of
particle, momentum and heat. Local linear analysis shows that the GAM frequency
increases with collisionality at low radial wave number and decreases
at high . GAM frequency also decreases with plasma beta. Radial profiles
of GAM frequency for two Tore Supra shots, which were part of a collisionality
scan, are compared with these calculations. Discrepency between experiment and
theory is observed, which seems to be explained by a finite for the GAM
when flux surface averaged density and temperature are assumed to vanish. It is shown that this agreement is incidental
and self-consistent inclusion of and
responses enhances the disagreement more with at high . So the
discrepancy between the linear GAM calculation, (which persist also for more
"complete" linear models such as gyrokinetics) can probably not be resolved by
simply adding a finite
Contribution of the frontal lobe to externally and internally specified verbal responses : fMRI evidence
It has been suggested that within the frontal cortex there is a lateral to medial shift in the control of action, with the lateral premotor area (PMA) involved in externally specified actions and the medial supplementary motor areas (SMA) involved in internally specified actions. Recent brain imaging studies demonstrate, however, that the control of externally and internally specified actions may involve more complex and overlapping networks involving not only the PMA and the SMA, but also the pre-SMA and the lateral prefrontal cortex (PFC). The aim of the present study was to determine whether these frontal regions are differentially involved in the production of verbal responses, when they are externally specified and when they are internally specified. Participants engaged in three overt speaking tasks in which the degree of response specification differed. The tasks involved reading aloud words (externally specified), or generating words aloud from narrow or broad semantic categories (internally specified). Using fMRI, the location and magnitude of the BOLD activity for these tasks was measured in a group of ten participants. Compared with rest, all tasks activated the primary motor area and the SMA-proper, reflecting their common role in speech production. The magnitude of the activity in the PFC (Brodmann area 45), the left PMAv and the pre-SMA increased for word generation, suggesting that each of these three regions plays a role in internally specified action selection. This confirms previous reports concerning the participation of the pre-SMA in verbal response selection. The pattern of activity in PMAv suggests participation in both externally and internally specified verbal actions
Accurate measurement of a 96% input coupling into a cavity using polarization tomography
Pillar microcavities are excellent light-matter interfaces providing an
electromagnetic confinement in small mode volumes with high quality factors.
They also allow the efficient injection and extraction of photons, into and
from the cavity, with potentially near-unity input and output-coupling
efficiencies. Optimizing the input and output coupling is essential, in
particular, in the development of solid-state quantum networks where artificial
atoms are manipulated with single incoming photons. Here we propose a technique
to accurately measure input and output coupling efficiencies using polarization
tomography of the light reflected by the cavity. We use the residual
birefringence of pillar microcavities to distinguish the light coupled to the
cavity from the uncoupled light: the former participates to rotating the
polarization of the reflected beam, while the latter decreases the polarization
purity. Applying this technique to a micropillar cavity, we measure a output coupling and a input coupling with unprecedented
precision.Comment: 6 pages, 3 figure
On the selection of words and oral motor responses : evidence of a response-independent fronto-parietal network
Several brain areas including the medial and lateral premotor areas, and the prefrontal cortex, are thought to be involved in response selection. It is unclear, however, what the specific contribution of each of these areas is. It is also unclear whether the response selection process operates independent of response modality or whether a number of specialized processes are recruited depending on the behaviour of interest. In the present study, the neural substrates for different response selection modes (volitional and stim- ulus-driven) were compared, using sparse-sampling functional magnetic resonance imaging, for two different response modalities: words and comparable oral motor gestures. Results demonstrate that response selection relies on a network of prefrontal, premotor and parietal areas, with the pre-supplementary motor area (pre-SMA) at the core of the process. Overall, this network is sensitive to the manner in which responses are selected, despite the absence of a medio-lateral axis, as was suggested by Goldberg (1985). In contrast, this network shows little sensitivity to the modality of the response, suggesting of a domain-general selection process. Theoretical implications of these results are discussed
Contribution of the pre-SMA to the production of words and non-speech oral motor gestures, as revealed by repetitive transcranial magnetic stimulation (rTMS)
An emerging theoretical perspective, largely based on neuroimaging studies, suggests that the pre-SMA is involved in planning cognitive aspects of motor behavior and language, such as linguistic and non-linguistic response selection. Neuroimaging studies, however, cannot indicate whether a brain region is equally important to all tasks in which it is activated. In the present study, we tested the hypothesis that the pre-SMA is an important component of response selection, using an interference technique. High frequency repetitive TMS (10 Hz) was used to interfere with the functioning of the pre-SMA during tasks requiring selection of words and oral gestures under different selection modes (forced, volitional) and attention levels (high attention, low attention). Results show that TMS applied to the pre-SMA interferes selectively with the volitional selection condition, resulting in longer RTs. The low- and high-attention forced selection conditions were unaffected by TMS, demonstrating that the pre-SMA is sensitive to selection mode but not attentional demands. TMS similarly affected the volitional selection of words and oral gestures, reflecting the response- independent nature of the pre-SMA contribution to response selection. The implications of these results are discussed
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