Upper critical dimension of the KPZ equation

Numerical results for the Directed Polymer model in 1+4 dimensions in various types of disorder are presented. The results are obtained for system size considerably larger than that considered previously. For the extreme strong disorder case (Min-Max system), associated with the Directed Percolation model, the expected value of the meandering exponent, zeta = 0.5 is clearly revealed, with very week finite size effects. For the week disorder case, associated with the KPZ equation, finite size effects are stronger, but the value of seta is clearly seen in the vicinity of 0.57. In systems with "strong disorder" it is expected that the system will cross over sharply from Min-Max behavior at short chains to weak disorder behavior at long chains. This is indeed what we find. These results indicate that 1+4 is not the Upper Critical Dimension (UCD) in the week disorder case, and thus 4+1 does not seem to be the upper critical dimension for the KPZ equation

Airbag vent valve and system

An energy absorbing airbag system includes one or more vent valve assemblies for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event. Each vent valve assembly includes a cantilever spring that is flat in an unstressed condition and that has a free end portion. The cantilever spring is secured to an exterior surface of the airbag housing and flexed to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a vent port or a closure covering the vent port to seal the vent port until inflation gas pressure within the airbag reaches a preselected value determined by the preset force whereupon the free end portion of the cantilever spring is lifted from the vent port by the inflation gases within the airbag to vent the inflation gases from within the airbag. The resilience of the cantilever spring maintains a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event by causing the cantilever spring to vent gases through the vent port whenever the pressure of the inflation gases reaches the preselected value and by causing the cantilever spring to close the vent port whenever the pressure of the inflation gases falls below the preselected value

Coherence-enhanced imaging of a degenerate Bose gas

We present coherence-enhanced imaging, an in situ technique that uses Raman superradiance to probe the spatial coherence properties of an ultracold gas. Applying this method, we obtain a spatially resolved measurement of the condensate number and more generally, of the first-order spatial correlation function in a gas of $^{87}$Rb atoms. We observe the enhanced decay of propagating spin gratings in high density regions of a Bose condensate, a decay we ascribe to collective, non-linear atom-atom scattering. Further, we directly observe spatial inhomogeneities that arise generally in the course of extended sample superradiance.Comment: 4 pages, 4 figure

A Survey of University Policy Makers' Preferences and Expectations for Provincial Examinations

A survey was conducted of persons responsible for making undergraduate admission policies at Ontario universities to ascertain their preferences and expectations for provincial examinations. Fifty-eight individuals, at least two from each university, responded to a series of questions by telephone interview or questionnaire. Strong support was expressed for the reintroduction of provincial examinations for mathematics and first language (English or français) courses in the final year of the secondary school program. Most respondents rejected the use of scores on province-wide examinations for rating secondary schools and adjusting school marks. Instead, they expressed a preference for having applicants report both teacher-assigned course marks and provincial examination scores.Nous avons mené une enquête auprès des personnes responsables des règlements d'admission au premier cycle dans les universités de l'Ontario afin de connaître leurs attentes et préférences au sujet des examens provinciaux. Cinquante-huit personnes, dont au moins deux de chaque université, ont répondu à une série de questions par voie téléphonique ou par questionnaire. Les répondants ont montré une forte tendance en faveur de la ré-introduction d'examens provinciaux pour les mathématiques et la langue première (l'anglais ou le français), examens qui seraient administrés à la fin de la dernière année d'école secondaire. La plupart on rejeté l'idée de se servir des résultats de ces examens pour l'évaluation des écoles secondaires et pour le réajustement des notes scolaires. En fait, ils préféreraient que les candidats présentent les notes accordées par leurs enseignants ainsi que les résultats de leurs examens

The Metallicity and Reddening of Stars in the Inner Galactic Bulge

We present a preliminary analysis of K, J-K color magnitude diagrams (CMDs) for 7 different positions on or close to the minor axis of the Milky Way at Galactic latitudes between +0.1^\circ and -2.8^\circ. From the slopes of the (linear) giant branches in these CMDs we derive a dependence of on latitude for b between -0.8^\circ and -2.8^\circ of -0.085 \pm 0.033 dex/degree. When combined with the data from Tiede et al. we find for -0.8^\circ \leq b \leq -10.3^\circ the slope in is -0.064 \pm 0.012 dex/degree. An extrapolation to the Galactic Center predicts [Fe/H] = +0.034 \pm 0.053 dex. We also derive average values for the extinction in the K band (A_K) of between 2.15 and 0.27 for the inner bulge fields corresponding to average values of E(J-K) of between 3.46 and 0.44. There is a well defined linear relation between the average extinction for a field and the star-to-star scatter in the extinction for the stars within each field. This result suggests that the typical apparent angular scale size for an absorbing cloud is small compared with the field size (90\arcsec on a side). Finally, from an examination of the luminosity function of bright giants in each field we conclude that the young component of the stellar population observed near the Galactic center declines in density much more quickly than the overall bulge population and is undetectable beyond 1^\circ from the Galactic center.Comment: accepted for publication in Astron. Jour. Compressed file contains the text, 9 figures, and 6 tables prepared with AAS Latex macros v. 4.

High-Resolution Magnetometry with a Spinor Bose-Einstein Condensate

We demonstrate a precision magnetic microscope based on direct imaging of the Larmor precession of a $^{87}$Rb spinor Bose-Einstein condensate. This magnetometer attains a field sensitivity of 8.3 pT/Hz$^{1/2}$ over a measurement area of 120 $\mu$m$^2$, an improvement over the low-frequency field sensitivity of modern SQUID magnetometers. The corresponding atom shot-noise limited sensitivity is estimated to be 0.15 pT/Hz$^{1/2}$ for unity duty cycle measurement. The achieved phase sensitivity is close to the atom shot-noise limit suggesting possibilities of spatially resolved spin-squeezed magnetometry. This magnetometer marks a significant application of degenerate atomic gases to metrology

Where I Live (2nd grade)

Students will learn utilization of maps and their elements. They will also learn about physical and human characteristics of communities. The goal of this unit is to help students understand that maps tell the story of a community and that people modify their physical environment to meet their needs. Through station exploration, map reading practice, creating digital maps, and exploring the local neighborhood, students with a variety of learning modalities will internalize the purpose of maps. Students transfer their knowledge and skills at the end of the unit by designing a community and creating a map to represent that community

Research Themes, Authors, and Methodologies in the Journal of Applied Communications: A Ten-Year Overview

The Journal of Applied Communications ( JAC) has been a primary outlet of agricultural communications research and professional scholarship—a claim validated by a survey of professionals in the field. The purpose of this study was to assess ten years of JAC to determine primary and secondary research themes, frequent primary and secondary research themes by year, prolific authorship, and research methods and types reported, using a mixed-methods design. Analyzed in the study were 91 research and/or professional articles with research methodologies published from 1997 through 2006. The research identified twenty-one primary research theme areas and 28 secondary research theme areas. A compiled list of primary and secondary research theme areas and frequent themes identified by year are reported. JAC authors were identified totaling 222 contributors; Tracy Irani and Ricky Telg (13.2%) were the most prolific authors. A majority of the articles (65.9%) employed quantitative research methods, and survey methodology (47.3%) was the most common data collection measure. Research themes appear cyclic, with specific themes moving in and out of primary and secondary areas, which may contribute to research theme diversity. Research must continue to determine whether cycles exist; if cycles do indeed exist then focus should be placed on determining cycle depth and the influence on research in agricultural communications as an integrated specialization area of agricultural education. This research should be used comparatively with priority areas identified in the National Research Agenda: Agricultural Education and Communication, 2007–2010, to determine where future research might be focused

Lived Experiences during International Service Learning: A Semiotic Analysis of Photo Journals

International service learning (ISL) is a pedagogical approach used to prepare students to be global citizens and has emerged as a popular short-term program model for international experiences. Few studies of ISL have integrated semiotic photo analysis into their evaluations. Combining students’ photographs with text encourages reflection on knowledge and experiences as well as how they are related. The current study used semiotic analysis to understand the lived experiences of students on an ISL to Guatemala. The participatory nature of the research process was critical to the semiotic analysis, as the researchers had an understanding of the cultural perspectives and traditions that emerged in the images which could have been overlooked by a researcher without knowledge of the specific cultural context. Participants kept a photo journal of 10 images and associated narratives to depict their experiences on the ISL. Both semiotic and content analysis were conducted on each journal entry. Coding yielded nine themes: new perspectives, personal connections, impact of coffee, intercultural comparisons, reality of life in Guatemala, cultural values, impact of ISL, connection to photograph, and sense of place. Combining the semiotic and content analysis yielded concurrent meanings through narrative and visual reflections, which, when combined with the researchers’ participatory knowledge of the experience, informed future ISL projects for the research and teaching team. The combination of visual and narrative methods required students to think about what story they will tell about their experience, and brings new layers of meaning to the reflection process

Mapping the cellular electrophysiology of rat sympathetic preganglionic neurones to their roles in cardiorespiratory reflex integration:A whole cell recording study in situ

Sympathetic preganglionic neurones (SPNs) convey sympathetic activity flowing from the CNS to the periphery to reach the target organs. Although previous in vivo and in vitro cell recording studies have explored their electrophysiological characteristics, it has not been possible to relate these characteristics to their roles in cardiorespiratory reflex integration. We used the working heart–brainstem preparation to make whole cell patch clamp recordings from T3–4 SPNs (n = 98). These SPNs were classified by their distinct responses to activation of the peripheral chemoreflex, diving response and arterial baroreflex, allowing the discrimination of muscle vasoconstrictor-like (MVC(like), 39%) from cutaneous vasoconstrictor-like (CVC(like), 28%) SPNs. The MVC(like) SPNs have higher baseline firing frequencies (2.52 ± 0.33 Hz vs. CVC(like) 1.34 ± 0.17 Hz, P = 0.007). The CVC(like) have longer after-hyperpolarisations (314 ± 36 ms vs. MVC(like) 191 ± 13 ms, P < 0.001) and lower input resistance (346 ± 49  MΩ vs. MVC(like) 496 ± 41 MΩ, P < 0.05). MVC(like) firing was respiratory-modulated with peak discharge in the late inspiratory/early expiratory phase and this activity was generated by both a tonic and respiratory-modulated barrage of synaptic events that were blocked by intrathecal kynurenate. In contrast, the activity of CVC(like) SPNs was underpinned by rhythmical membrane potential oscillations suggestive of gap junctional coupling. Thus, we have related the intrinsic electrophysiological properties of two classes of SPNs in situ to their roles in cardiorespiratory reflex integration and have shown that they deploy different cellular mechanisms that are likely to influence how they integrate and shape the distinctive sympathetic outputs