1,055 research outputs found
24 and the Efficacy of Torture
In the Fox Television Network program 24 a fictional counterterrorism agent named Jack Bauer uses extreme measures, including torture, to save the United States from catastrophic terrorist attacks. Bauer uses torture even though its efficacy is in question and it is illegal. Political leaders, including President George Bush, have endorsed the use of torture and Bauer\u27s fictional success has reinforced that the idea these methods are both necessary and effective in obtaining actionable intelligence. This paper examines existing literature on military interrogations in the context of 24 and reviews empirical and descriptive evidence about existing practices. While researchers cannot ethically or legally test torture\u27s effectiveness, more research is needed to study methods currently in use by the military
First polarimetric observations and modeling of the FeH F^4 Delta-X^4 Delta system
Lines of diatomic molecules are more temperature and pressure sensitive than
atomic lines, which makes them ideal tools for studying cool stellar
atmospheres an internal structure of sunspots and starspots. The FeH F^4
Delta-X^4 Delta system represents such an example that exhibits in addition a
large magnetic field sensitivity. The current theoretical descriptions of these
transitions including the molecular constants involved are only based on
intensity measurements because polarimetric observations have not been
available so far, which limits their diagnostic value. We present for the first
time spectropolarimetric observations of the FeH F^4 Delta-X^4 Delta system
measured in sunspots to investigate their diagnostic capabilities for probing
solar and stellar magnetic fields. We investigate whether the current
theoretical model of FeH can reproduce the observed Stokes profiles including
their magnetic properties. The polarimetric observations are compared with
synthetic Stokes profiles modeled with radiative transfer calculations. This
allows us to infer the temperature and the magnetic field strength of the
observed sunspots. We find that the current theory successfully reproduces the
magnetic properties of a large number of lines in the FeH F^4 Delta-X^4 Delta
system. In a few cases the observations indicate a larger Zeeman splitting than
predicted by the theory. There, our observations have provided additional
constraints, which allowed us to determine empirical molecular constants. The
FeH F^4 Delta-X^4 Delta system is found to be a very sensitive magnetic
diagnostic tool. Polarimetric data of these lines provide us with more direct
information to study the coolest parts of astrophysical objects.Comment: 4 pages, 3 figure
Effects in polarimetry of interference within wave plates
Multiple-beam interference within wave plates is investigated in terms of the detrimental effects it produces in the data of stellar spectropolarimetry. It is noted that spectral fringe structures occur in the phase delay, the polarizance and, for Pancharatnam designs, the reference axis of the wave plate. The natures of the problems are exposed by considering typical wave plates and experimental procedures used in linear and circular spectropolarimetry. It is demonstrated that the chief bane of accurate measurements is the presence of polarizance fringes, but which can be alleviated by the choice of experimental procedure. For spectral circular polarization studies, problems of cross-talk from any linear polarization present in the source are especially severe. In principle the effects of fringing can be removed in data reductions by calibration measurements of a set of linear polarization standard stars displaying different vibration azimuths and, for circular polarization measurements, knowledge of the linear polarization characteristics of the investigated star must also be known
Critical evaluation of magnetic field detections reported for pulsating B-type stars in the light of ESPaDOnS, Narval and reanalyzed FORS1/2 observations
Recent spectropolarimetric studies of 7 SPB and Cep stars have
suggested that photospheric magnetic fields are more common in B-type pulsators
than in the general population of B stars, suggesting a significant connection
between magnetic and pulsational phenomena. We present an analysis of new and
previously published spectropolarimetric observations of these stars. New
Stokes observations obtained with the high-resolution ESPaDOnS and Narval
instruments confirm the presence of a magnetic field in one of the stars
( Lup), but find no evidence of magnetism in 5 others. A re-analysis
of the published longitudinal field measurements obtained with the
low-resolution FORS1/2 spectropolarimeters finds that the measurements of all
stars show more scatter from zero than can be attributed to Gaussian noise,
suggesting the presence of a signal and/or systematic under-estimation of error
bars. Re-reduction and re-measurement of the FORS1/2 spectra from the ESO
archive demonstrates that small changes in reduction procedure lead to
substantial changes in the inferred longitudinal field, and substantially
reduces the number of field detections at the 3 level. Furthermore, we
find that the published periods are not unique solutions to the time series of
either the original or the revised FORS1/2 data. We conclude that the reported
field detections, proposed periods and field geometry models for Pyx,
15 CMa, 33 Eri and V1449 Aql are artefacts of the data analysis and reduction
procedures, and that magnetic fields at the reported strength are no more
common in SPB/ Cep stars than in the general population of B stars.Comment: 10 pages, 5 figures, accepted for publication in ApJ, 2012, typo
correcte
Surface differential rotation and photospheric magnetic field of the young solar-type star HD 171488 (V889 Her)
We present spectropolarimetric observations of the young, single early G-dwarf HD 171488. These observations were obtained over a five-night period in 2004 September at the 3.9-m Anglo-Australian Telescope using the SEMPOL spectropolarimeter visitor instrument. Using the technique of least-squares deconvolution to increase the signal-to-noise ratio of the data, we have applied Zeeman Doppler imaging to reconstruct brightness and magnetic surface topologies of the star. The brightness image shows a large polar spot with weaker low- to mid-latitude features, confirming an earlier Doppler imaging observation. The reconstruction of the surface magnetic field shows regions of radial field at all latitudes (except near the pole) and regions of azimuthal field predominantly at high latitudes (60°-70°), with the azimuthal field almost forming a ring around the polar regions. We have incorporated a solar-like differential rotation law into the imaging process to determine the surface differential rotation of cool spots on HD 171488. This gives an equatorial rotation rate of 1.313 ± 0.004 d and a surface shear of dΩ= 0.402 ± 0.044 rad-dâ1. This means that the equator of HD 171488 laps the poles every âŒ16 ± 2 d and that HD 171488 has a photospheric shear approximately seven times the solar value. This is the largest measurement of surface differential rotation yet obtained using the Doppler imaging method and is over twice the value of previously observed early G-dwarf
High Resolution Spectroscopy and Spectropolarimetry of some late F-/early G-type sun-like stars as targets for Zeeman Doppler imaging
High resolution spectroscopy and spectropolarimetry have been undertaken at
the Anglo-Australian Telescope in order to identify suitable targets for
magnetic studies of young sun-like stars, for the proxy study of early solar
evolution. This study involved the investigation of some variable late F-/early
G-type sun-like stars originally identified by the Hipparcos mission. Of the 38
stars observed for this study, HIP 31021, HIP 64732, HIP 73780 were found to be
spectroscopic binary stars while HIP 19072, HIP 67651 and HIP 75636 are also
likely to be binaries while HIP 33111 could even be a triple system. Magnetic
fields were detected on a number of the survey stars: HIP 21632, HIP 43720, HIP
48770, HIP 62517, HIP 71933, HIP 77144, HIP 89829, HIP 90899 and HIP 105388,
making these stars good candidates for follow-up Zeeman Doppler imaging
studies.Comment: 16 pages, 16 figures, 4 tables Accepted for publication in PAS
Indirect imaging of nonradial pulsations in a rapidly oscillating Ap star
Many types of stars show periodic variations of radius and brightness, which
are commonly referred to as `stellar pulsations'. Observed pulsational
characteristics are determined by fundamental stellar parameters. Consequently,
investigations of stellar pulsations provide a unique opportunity to verify and
refine our understanding of the evolution and internal structure of stars.
However, a key boundary condition for this analysis -- precise information
about the geometry of pulsations in the outer stellar envelopes -- has been
notoriously difficult to secure. Here we demonstrate that it is possible to
solve this problem by constructing an `image' of the pulsation velocity field
from time series observations of stellar spectra. This technique is applied to
study the geometry of nonradial pulsations in a prototype magnetic oscillating
(roAp) star HR 3831. Our velocity map directly demonstrates an alignment of
pulsations with the axis of the global magnetic field and reveals a significant
magnetically induced distortion of pulsations. This observation constitutes a
long-sought solution of the problem of the pulsation geometry of roAp stars and
enables very stringent tests of the recent theories of stellar magneto-acoustic
oscillations.Comment: accepted by ApJ Letter
Financial capability and functional financial literacy in young adults with developmental language disorder
Background: Financial capability is an essential feature of the organisation of oneâs personal life and engagement with society. Very little is known of how adequately individuals with developmental language disorder (DLD) handle financial matters. It is known that language difficulties place them at a disadvantage in many aspects of their development and during their transition into adulthood, leading to the possibility that financial issues may prove burdensome for them. This study examines the financial capability and functional financial literacy of young adults with DLD and compares them to those of age matched peers (AMPs). We tested the expectation that those with DLD would find financial management more challenging than would their peers, and that they would need to seek greater support from family members or other people.
Methods: Participants completed a detailed individual interview, which included items drawn from the British Household Panel Survey and additional measures of financial capability, functional financial literacy and of perceived support. Nonverbal IQ, language, reading and numeracy measures were also collected.
Results: Compared to typically developing AMPs, young people with DLD report less extensive engagement with financial products and lower competence in functional financial literacy. A considerably higher proportion of those with DLD (48% vs 16% of AMPs) report that they draw on support, primarily from parents, in various financial tasks, including paying bills, choosing financial products, and taking loans from family or friends.
Conclusions: This is the first study to consider the financial capability skills and functional financial literacy of young adults with DLD. We provide novel evidence that some young adults with DLD lack functional financial skills and require support to successfully manage their finances. This has policy implications that relate not only to engaging affected individuals in discussions about financial management but also to wider familial support
Chronic dermatomycoses of the foot as risk factors for acute bacterial cellulitis of the leg: A case-control study
Objective: To assess the role of foot dermatomycosis ( tinea pedis and onychomycosis) and other candidate risk factors in the development of acute bacterial cellulitis of the leg. Methods: A case-control study, including 243 patients ( cases) with acute bacterial cellulitis of the leg and 467 controls, 2 per case, individually matched for gender, age (+/-5 years), hospital and admission date (+/-2 months). Results: Overall, mycology-proven foot dermatomycosis was a significant risk factor for acute bacterial cellulitis (odds ratio, OR: 2.4; p < 0.001), as were tinea pedis interdigitalis (OR: 3.2; p < 0.001), tinea pedis plantaris (OR: 1.7; p = 0.005) and onychomycosis (OR: 2.2; p < 0.001) individually. Other risk factors included: disruption of the cutaneous barrier, history of bacterial cellulitis, chronic venous insufficiency and leg oedema. Conclusions: Tinea pedis and onychomycosis were found to be significant risk factors for acute bacterial cellulitis of the leg that are readily amenable to treatment with effective pharmacological therapy. Copyright (C) 2004 S. Karger AG, Basel
Bilingualism alters childrenâs frontal lobe functioning for attentional control
Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on childrenâs cognitive and brain development. Theories of bilingualism suggest that early dualĂą language acquisition can improve childrenâs cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on childrenâs frontal lobe development. Using functional nearĂą infrared spectroscopy (fNIRS), the findings suggest that SpanishĂą English bilingual children (nĂÂ =ĂÂ 13, ages 7Ăą 13) had greater activation in left prefrontal cortex during a nonĂą verbal attentional control task relative to ageĂą matched English monolinguals. In contrast, monolinguals (nĂÂ =ĂÂ 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of childrenâs prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.This fNIRS study investigated the impact of bilingual exposure on childrenâs brain organization for attentional control (N = 27, ages 7Ăą 13). During a nonĂą verbal attention task, bilinguals showed greater left frontal lobe activation than monolinguals. Monolinguals showed greater right frontal lobe activation than bilinguals. The findings suggest that bilingualism affects the functionality of childrenâs left prefrontal cortex for attentional control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/1/desc12377-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/2/desc12377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/3/desc12377_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/4/desc12377-sup-0003-SupInfo.pd
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