670 research outputs found
The ``Out-Longitudinal'' Cross Term and Other Model Independent Features of the Two-Particle HBT Correlation Function
Using two specific models and a model independent formalism, we show that an
``out-longitudinal'' cross term should be included in any gaussian fits to
correlation data. In addition, we show that correlation radii (including the
cross term) measure lengths of homogeneity within the source, not necessarily
geometric sizes.Comment: 4 pages, uuencoded compressed postscrip
Childrenâs comprehension monitoring of multiple situational dimensions of a narrative
Narratives typically consist of information on multiple aspects of a situation. In order to successfully create a coherent representation of the described situation, readers are required to monitor all these situational dimensions during reading. However, little is known about whether these dimensions differ in the ease with which they can be monitored. In the present study, we examined whether children in Grades 4 and 6 monitor four different dimensions (i.e., emotion, causation, time, and space) during reading, using a self-paced reading task containing inconsistencies. Furthermore, to explore what causes failure in inconsistency detection, we differentiated between monitoring processes related to availability and validation of information by manipulating the distance between two pieces of conflicting information. The results indicated that the monitoring processes varied as a function of dimension. Children were able to validate emotional and causal information when it was still active in working memory, but this was not the case for temporal and spatial information. When context and target information were more distant from each other, only emotionally charged information remained available for further monitoring processes. These findings show that the influence of different situational dimensions should be taken into account when studying childrenâs reading comprehension
Children's integration of information across texts: reading processes and knowledge representations.
Constructing a knowledge representation from multiple texts requires the integration of information across texts. The aim of the current study was to investigate how elementary school students integrate information across multiple text passages and, particularly, whether students use information from a prior text to improve understanding of a current text. A sample of 105 children in grades 4 and 6 participated in the experiment. The multiple-text integration paradigm was used to study integration processes across texts during reading. Recall and (application) questions were used to investigate the extent to which information from different text passages was integrated into knowledge representations after reading. Individual differences in reading comprehension ability and working memory were also considered. The results indicate that children in both grades spontaneously activate information from an earlier text to aid their understanding during reading, and that they integrate information across texts in their knowledge representations. This was the case regardless of grade or individual differences in reading-comprehension ability and working memory. These findings provide insight into the mechanisms that may be involved in the integration of information across texts.Development Psychopathology in context: schoo
Observing Non-Gaussian Sources in Heavy-Ion Reactions
We examine the possibility of extracting non-Gaussian sources from
two-particle correlations in heavy-ion reactions. Non-Gaussian sources have
been predicted in a variety of model calculations and may have been seen in
various like-meson pair correlations. As a tool for this investigation, we have
developed an improved imaging method that relies on a Basis spline expansion of
the source functions with an improved implementation of constraints. We examine
under what conditions this improved method can distinguish between Gaussian and
non-Gaussian sources. Finally, we investigate pion, kaon, and proton sources
from the p-Pb reaction at 450 GeV/nucleon and from the S-Pb reaction at 200
GeV/nucleon studied by the NA44 experiment. Both the pion and kaon sources from
the S-Pb correlations seem to exhibit a Gaussian core with an extended,
non-Gaussian halo. We also find evidence for a scaling of the source widths
with particle mass in the sources from the p-Pb reaction.Comment: 16 pages, 15 figures, 5 tables, uses RevTex3.
Caracterização do nĂvel de oxidação de glutationa durante a dormĂȘncia hibernal em gemas de macieira.
A macieira (Malus x domestica) apresenta a queda de folhas no final do ciclo e o estabelecimento da donnĂȘncia hibemal (endodonnĂȘncia). Durante a endodonnĂȘncia, as plantas necessitam de regularidade e intensidade de baixas temperaturas para que iniciem a brotação e se estabeleça um novo ciclo vegetativo e produtivo. Entretanto, em regiĂ”es de clima temperado, como a RegiĂŁo Sul do Brasil, em muitos invemos ocorrem flutuaçÔes de temperatura que resultam em quedas de produção.Resumo
MHC-B variation in maternal and paternal synthetic lines of the Argentinian Campero INTA chicken
The Campero-INTA chicken of Argentina was developed to provide a robust bird that can survive under Argentinian pasture conditions with no significant additional nutrition, producing a source of animal protein for small producers or low-income families. In previous work we described the AH paternal line of Campero and its Major Histocompatibility Complex B region (MHC-B) variation. In this work we analyzed the three remaining synthetic lines used to produce the Campero-INTA production bird: lines AS, A and E. Because of the association between variation within the MHC of chickens and disease resistance, MHC variation within this breed is of particular interest. MHC variability within the lines used to produce the Campero-INTA chicken was examined using a 90 SNP panel encompassing the chicken MHC-B region plus the VNTR, LEI0258, located within the chicken MHC. Across all four lines 12 haplotypes were found, with 7 of these being previously reported in North America/European breeds, reflecting the original breed sources for these birds. Three Campero unique haplotypes were found, two of which likely originated from MHC recombination events. MHC-B variation for all lines involved with production of the final Campero-INTA bird have now been determined.EEA PergaminoFil: Iglesias, Gabriela M. Universidad Nacional de RĂo Negro. Sede Alto Valle y Valle Medio. Escuela de Veterinaria y ProducciĂłn Agroindustrial. CĂĄtedra de GenĂ©tica; ArgentinaFil: Beker, MarĂa P. Universidad Nacional de RĂo Negro. Sede Alto Valle y Valle Medio. Escuela de Veterinaria y ProducciĂłn Agroindustrial. CĂĄtedra de GenĂ©tica; ArgentinaFil: Remolins, JosĂ© S. Universidad Nacional de RĂo Negro. Sede Alto Valle y Valle Medio. Escuela de Veterinaria y ProducciĂłn Agroindustrial. CĂĄtedra de GenĂ©tica; ArgentinaFil: Canet, Zulma Edith. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Pergamino. SecciĂłn Avicultura; ArgentinaFil: Canet, Zulma Edith. Universidad Nacional de Rosario. Facultad de Ciencias Veterinaria. CĂĄtedra de GenĂ©tica; ArgentinaFil: Librera, JosĂ©. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. CĂĄtedra de GenĂ©tica; ArgentinaFil: Cantaro, Horacio Luis. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Alto Valle; ArgentinaFil: Cantaro, Horacio Luis. Universidad Nacional de RĂo Negro. Sede Alto Valle y Valle Medio. Escuela de Veterinaria y ProducciĂłn Agroindustrial. CĂĄtedra de GenĂ©tica; ArgentinaFil: Maizon, Daniel Omar Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Anguil; ArgentinaFil: Fulton, Janet E. Hy-Line International; Estados Unido
Improving the sensitivity of future GW observatories in the 1-10 Hz band: Newtonian and seismic noise
The next generation gravitational wave interferometric detectors will likely be underground detectors to extend the GW detection frequency band to frequencies below the Newtonian noise limit. Newtonian noise originates from the continuous motion of the Earthâs crust driven by human activity, tidal stresses and seismic motion, and from mass density fluctuations in the atmosphere. It is calculated that on Earthâs surface, on a typical day, it will exceed the expected GW signals at frequencies below 10 Hz. The noise will decrease underground by an unknown amount. It is
important to investigate and to quantify this expected reduction and its effect on the sensitivity of future detectors, to plan for further improvement strategies. We report about some of these aspects. Analytical models can be used in the simplest scenarios to get a better qualitative and semi-quantitative understanding. As more complete modeling can be done numerically, we will discuss also some results obtained with a finite-element-based modeling tool. The method is verified by comparing its results with the results of analytic calculations for surface detectors. A key point about noise models is their initial parameters and conditions, which require detailed information about seismic motion in a real scenario. We will describe an effort to characterize the seismic activity at the Homestake mine which is currently in progress. This activity is specifically aimed to provide informations and to explore the site as a possible candidate for an underground observatory. Although the only compelling reason to put the interferometer underground is to reduce the Newtonian noise, we expect that the more stable underground environment will have a more general positive impact on the sensitivity.We will end this report with some considerations about seismic and suspension noise
Baryon phase-space density in heavy-ion collisions
The baryon phase-space density at mid-rapidity from central heavy-ion
collisions is estimated from proton spectra with interferometry and deuteron
coalescence measurements. It is found that the mid-rapidity phase-space density
of baryons is significantly lower at the SPS than the AGS, while those of total
particles (pion + baryon) are comparable. Thermal and chemical equilibrium
model calculations tend to over-estimate the phase-space densities at both
energies.Comment: 5 pages, 2 tables, no figure. RevTeX style. Accepted for publication
in Phys. Rev. C Rapid Communicatio
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