810 research outputs found
3D Spectroscopic Observations of Star-Forming Dwarf Galaxies
We give an introduction into the observational technique of integral field or
3D spectroscopy. We discuss advantages and drawbacks of this type of
observations and highlight a few science projects enabled by this method. In
the second part we describe our 3D spectroscopic survey of Blue Compact Dwarf
Galaxies. We show preliminary results from data taken with the VIMOS integral
field unit and give an outlook on how automated spectral analysis and
forthcoming instruments can provide a new view on star formation and associated
processes in dwarf galaxies.Comment: To appear in the proceedings of the JENAM 2010 Symposium "Dwarf
Galaxies: Keys to Galaxy Formation and Evolution" (Lisbon, 9-10 September
2010), P. Papaderos, S. Recchi, G. Hensler (eds.), Springer Verlag (2011), in
pres
Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar
Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds
The Second Step In The Construction Of A Stigma Scale Of Epilepsy
Rationale: The issue of stigmatization is one of the most common psychosocial problems faced by people with epilepsy. Purpose: A second step towards the development of a scale to measure epilepsy stigma. Method: We applied a closed questionnaire to 12 patients and 32 relatives from the Epilepsy Outpatient Clinic at the University Hospital of Campinas. Results: The results are grouped in three main domains: medical, social and personal areas. Medical: the subjects did not know exactly what epilepsy is or how it is caused; nonetheless they know how to treat it. Social: the most important areas that people with epilepsy are discriminated are at work and social relationships. Patients also complained about their lack of freedom and limits on recreation activities. Personal Area: subjects apparently have the same feelings and thoughts about epilepsy and seizures. Conclusion: This study analyzed the most common aspects presented in the questionnaire to assess epilepsy stigma for the Brazilian culture which are the base to the elaboration of a stigma scale of epilepsy.632 B395398Fernandes, P.T., Souza, E.A., Identification of family variables in parents' groups of children with epilepsy (2001) Arq Neuropsiquiatr, 59, pp. 854-858Li, L.M., Sander, J.W., National demonstration project on epilepsy in Brazil (2003) Arq Neuropsiquiatr, 61, pp. 153-156Leidy, N.K., Rentz, A.M., Grace, E.M., Evaluating health-related quality of life outcomes in clinical trials of antiepileptic drug therapy (2004) Epilepsia, 39, pp. 965-977Baker, G.A., Brooks, J., Buck, D., Jacoby, A., The stigma of epilepsy: A European perspective (2000) Epilepsia, 41, pp. 98-104Baker, G.A., Nashef, L., Van Hout, B.A., Current issues in the management of epilepsy: The impact of frequent seizures on cost of illness, quality of life, and mortality (1997) Epilepsia, 38 (SUPPL. 1), pp. S1-S8Baker, G.A., Jacoby, A., Chadwick, D.W., The associations of psychopathology in epilepsy: A community study (1996) Epilepsy Res, 25, pp. 29-39Jacoby, A., Felt versus enacted stigma: A concept revisited. Evidence from a study of people with epilepsy in remission (1994) Soc Sci Med, 38, pp. 269-274Placencia, M., Farmer, P.J., Jumbo, L., Sander, J.W., Shorvon, S.D., Levels of stigmatization of patients with previously untreated epilepsy in northern Ecuador (1995) Neuroepidemiology, 14, pp. 147-154Ratsepp, M., Oun, A., Haldre, S., Kaasik, A.E., Felt stigma and impact of epilepsy on employment status among Estonian people: Exploratory study (2000) Seizure, 9, pp. 394-401Scambler, G., Hopkins, A., Generating a model of epileptic stigma: The role of qualitative analysis (1990) Soc Sci Med, 30, pp. 1187-1194Ryan, R., Kempner, K., Emlen, A.C., The stigma of epilepsy as a self-concept (1980) Epilepsia, 21, pp. 433-444Fernandes, P.T., Salgado, P.C., Ala, N., Barbosa, F.D., Souza, E.A., Li, L.M., Stigma Scale of Epilepsy: Conceptual issues (2004) J Epilep Clin Neuropshysiology, 10, pp. 213-218McLin, W.M., De Boer, H.M., Public perceptions about epilepsy (1995) Epilepsia, 36, pp. 957-95
Texture analysis of computed tomography images of acute ischemic stroke patients
Computed tomography (CT) images are routinely used to assess ischemic brain stroke in the acute phase. They can provide important clues about whether to treat the patient by thrombolysis with tissue plasminogen activator. However, in the acute phase, the lesions may be difficult to detect in the images using standard visual analysis. The objective of the present study was to determine if texture analysis techniques applied to CT images of stroke patients could differentiate between normal tissue and affected areas that usually go unperceived under visual analysis. We performed a pilot study in which texture analysis, based on the gray level co-occurrence matrix, was applied to the CT brain images of 5 patients and of 5 control subjects and the results were compared by discriminant analysis. Thirteen regions of interest, regarding areas that may be potentially affected by ischemic stroke, were selected for calculation of texture parameters. All regions of interest for all subjects were classified as lesional or non-lesional tissue by an expert neuroradiologist. Visual assessment of the discriminant analysis graphs showed differences in the values of texture parameters between patients and controls, and also between texture parameters for lesional and non-lesional tissue of the patients. This suggests that texture analysis can indeed be a useful tool to help neurologists in the early assessment of ischemic stroke and quantification of the extent of the affected areas.1076107
Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
This paper reports a measurement of D*+/- meson production in jets from
proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the
CERN Large Hadron Collider. The measurement is based on a data sample recorded
with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets
with transverse momentum between 25 and 70 GeV in the pseudorapidity range
|eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay
chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate
is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for
D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z <
1. Monte Carlo predictions fail to describe the data at small values of z, and
this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table,
matches published version in Physical Review
Fluctuating asymmetry in dental and mandibular nonmetric traits as evidence for childcare sex bias in 19th/20th century Portugal.
Fluctuating asymmetry, often considered a measure of developmental instability, was studied in the dental morphological traits of 600 individuals from among the poorest sectors of society in 19th-20th century Portugal. The aims are to identify and interpret any differences between: (1) males and females, and (2) patterns of distribution among teeth with different odontogenic timings, to assess if any sex bias existed in childcare. Dental and mandibular morphological traits were recorded using the Arizona State University Dental Anthropology System. z-Ratios were used to compare summed absolute fluctuating asymmetry frequencies between sexes and age groups. Results from rank correlation coefficients ruled out directional asymmetry and antisymmetry, based on positive (>0.2) bilateral association of traits in larger samples. Sex differences were significant (z-ratio=3.128; p=0.0018), while age differences were not (z-ratio=-0.644; p=0.5196). Teeth forming after infancy tended to be more asymmetric in females. Potential reasons for the sex difference include: (1) greater female susceptibility to developmental instability, (2) greater male childhood mortality that yields lower fluctuating asymmetry in surviving males, and/or (3) cultural bias favoring male access to resources. Results suggest the latter hypothesis is most likely, as fluctuating asymmetry is enhanced during childhood, perhaps coinciding with gender role definitions. There seems to be no association between asymmetry and early mortality in males. A lack of parallels in prior research renders differential sex reaction to environmental stress dubious. This population may have favored male children in their access to appropriate conditions for development
PREVISÃO DE ESCORREGAMENTOS TRANSLACIONAIS RASOS E ÁREA DE DUTOS: ESTUDO DE CASO DO MACIÇO DO TINGUÁ NA RESERVA BIOLÓGICA FEDERAL DO TINGUÁ (RJ).
Os movimentos de massa são grandes causadores de prejuízos financeiros, podendo danificar redes de infraestrutura como oleodutos e gasodutos. O objetivo desse trabalho é realizar uma análise das condições de estabilidade das encostas do Maciço do Tinguá, na Reserva Biológica Federal do Tinguá (RJ), por onde passam oleodutos e gasodutos. Utilizou-se um modelo matemático de base física e os resultados propiciaram uma análise preliminar da susceptibilidade a escorregamentos translacionais na área
Near-intrinsic energy resolution for 30-662 keV gamma rays in a high pressure xenon electroluminescent TPC
We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 136Xe neutrino-less double beta decay (0νββ) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662 keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of ∼1% FWHM for 662 keV gamma rays were obtained at 10 and 15 atm and ∼5% FWHM for 30 keV fluorescence xenon X-rays. These results demonstrate that 0.5% FWHM resolutions for the 2,459 keV hypothetical neutrino-less double beta decay peak are realizable. This energy resolution is a factor 7 to 20 better than that of the current leading 0νββ experiments using liquid xenon and thus represents a significant advancement. We present also first results from a track imaging system consisting of 64 silicon photo-multipliers recently installed in NEXT-DBDM that, along with the excellent energy resolution, demonstrates the key functionalities required for the NEXT-100 0νββ search
Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data
We present an update of a search for supersymmetry in final states containing
jets, missing transverse momentum, and one isolated electron or muon, using
1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the
ATLAS experiment at the LHC in the first half of 2011. The analysis is carried
out in four distinct signal regions with either three or four jets and
variations on the (missing) transverse momentum cuts, resulting in optimized
limits for various supersymmetry models. No excess above the standard model
background expectation is observed. Limits are set on the visible cross-section
of new physics within the kinematic requirements of the search. The results are
interpreted as limits on the parameters of the minimal supergravity framework,
limits on cross-sections of simplified models with specific squark and gluino
decay modes, and limits on parameters of a model with bilinear R-parity
violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables,
final version to appear in Physical Review
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