4,125 research outputs found
Higher Order and Secondary Hochschild Cohomology
In this note we give a generalization for the higher order Hochschild
cohomology and show that the secondary Hochschild cohomology is a particular
case of this new construction
Measured electron contribution to Shuttle plasma environment: Abbreviated update
The differential energy spectra of electrons between 1 and 100 eV were measured by an electron spectrometer flown on an early shuttle. This energy range was scanned in 64 incremental steps with a resolution of 7%. The most striking feature that was observed throughout these spectra was a relatively flat distribution of the higher energy electrons out to 100 eV. This is in contrast to normal ambient spectra which consistently show a rapid decline in quantitative flux beyond 50 to 55 eV. The lower energy (1 to 2 eV) end of these spectra showed steep thermal trails comparable to normal ambient spectral structure. In general, daytime fluxes were significantly higher than those obtained during nighttime measurements. Quantitative flux excursions which may possibly be associated with thruster firing were frequently observed. Spectral structure suggestive of the N2 vibrational excitation energy loss mechanism was also seen in the data from some measurement periods. Examples of these spectra are shown and possible correlations are discussed
Perspectives from community-based doulas and mothers: Neighborhood context and pregnancy
Objectives: Limited research explores the potential pathways by which neighborhoods influence pregnancy or how community members conceptualize and interpret how neighborhood contexts and living environments influence pregnancy and birth.
Study Design: We applied participatory Concept Mapping and a series of focused discussions with community-based doulas and mothers.
Methods: We collaborated with a community-based doula program to investigate how mothers and community doulas perceived the neighborhood to influence reproductive health. We conducted a series of focused discussions including ‘Brainstorming’ to uncover key themes related to how neighborhood context influenced pregnancy, ‘Sorting and Rating’ of key themes in association with pregnancy and birth outcomes, and further discussion to uncover potential relationships. Data from the ‘Sorting and Rating’ activities were entered into Concept Systems software to generate concept maps of the themes and ideas discussed.
Results: The women identified 79 key themes/items related to the neighborhood context that they thought were important for pregnancy and birth. Participants ranked most of the neighborhood factors as moderate or high in importance in influencing pregnancy health and birth. These 79 items were further aggregated to develop 9 clusters related to various themes such as ‘Access/Potential Barriers to Adequate Care,’ ‘The Environment and Infrastructure,’ ‘Neighborhood History, Demographics and Dynamics,’ ‘Community, Relationships, and Autonomy.’ The group further discussed how neighborhood contexts have a particularly influence on individual behaviors such as physical activity; and how key infrastructure issues such as transportation may impede or facilitate access to resources important for health.
Conclusion: This study provides additional insight into how neighborhoods may influence pregnancy and birth and how multiple neighborhood factors may act synergistically to influence health. Concept mapping and community perspectives reinforce the importance of participant and community input in developing future research and interventions
High-contrast imaging of Sirius~A with VLT/SPHERE: Looking for giant planets down to one astronomical unit
Sirius has always attracted a lot of scientific interest, especially after
the discovery of a companion white dwarf at the end of the 19th century. Very
early on, the existence of a potential third body was put forward to explain
some of the observed properties of the system. We present new coronagraphic
observations obtained with VLT/SPHERE that explore, for the very first time,
the innermost regions of the system down to 0.2" (0.5 AU) from Sirius A. Our
observations cover the near-infrared from 0.95 to 2.3 m and they offer the
best on-sky contrast ever reached at these angular separations. After detailing
the steps of our SPHERE/IRDIFS data analysis, we present a robust method to
derive detection limits for multi-spectral data from high-contrast imagers and
spectrographs. In terms of raw performance, we report contrasts of 14.3 mag at
0.2", ~16.3 mag in the 0.4-1.0" range and down to 19 mag at 3.7". In physical
units, our observations are sensitive to giant planets down to 11 at
0.5 AU, 6-7 in the 1-2 AU range and ~4 at 10 AU. Despite
the exceptional sensitivity of our observations, we do not report the detection
of additional companions around Sirius A. Using a Monte Carlo orbital analysis,
we show that we can reject, with about 50% probability, the existence of an 8
planet orbiting at 1 AU. In addition to the results presented in the
paper, we provide our SPHERE/IFS data reduction pipeline at
http://people.lam.fr/vigan.arthur/ under the MIT license.Comment: 16 pages, 10 figures, accepted for publication in MNRA
Students use of laptops in large lecture classes: distraction, partial attention or productive use
http://editlib.org/p/34929ED-Media. World Conference on Educational Multimedia, Hypermedia & Telecommunications. Proceedings, 2010, v. 2010 n. 1, p. 2136-2141An increasing number of students are bringing personal laptops to their classes and are using laptops during lectures. This increasing use of personal mobile devices has been described as a shift from e-learning (electronic learning) to m-learning (mobile learning). However, a large debate on the appropriateness of the use of laptops in class has emerged. Many teachers describe that students use laptops for surfing the net, emailing, downloading software and using chat forums during class rather than paying attention to the lecture. This paper reports on the use of laptops in a large lecture class of 650+ students and describes a pilot project that introduced an innovative system that was designed to both focus the attention of students during the class and engage them with the course material outside of class. Educational implications and next steps will be discussed.postprin
Approaches to teaching and technology use among international award winning university teachers
There is wide-spread acknowledgement of the benefits of well thought out online learning opportunities that provide students with active learning environments that extend the classroom space. This paper reports on the approaches to teaching in general, and in particular approaches to the use of technology, by award winning university faculty in Canada, Australia and Hong Kong. Findings indicate that the majority of these award winning teachers adopted an approach to teaching that was student centered and focused on changing the students’ conceptions of the material being studied, rather than an approach that was information focused. While technology as a tool to provide information resources was a part of their repertoire, their use of technology extended beyond content delivery to provide activities and resources for active learning. Examples of how they incorporated technology for active learning will be provided.postprintThe World Conference on Educational Multimedia, Hypermedia & Telecommunications (EDMEDIA 2010), Toronto, Canada, 28 June-2 July 2010. In Proceedings of EDMEDIA, 2010, n. 1, p. 2565-257
Pseudo-noise test set for communication system evaluation
A test set for communications systems is described which includes a pseudo noise sequence generator providing a test signal that is fed to a pair of signal channels. The first channel includes a spectrum shaping filter and a conditioning amplifier. The second channel includes a variable delay circuit, a spectrum shaping filter matched to the first filter, and an amplifier. The output of the first channel was applied to the system under test. The output of the system and the output of the second channel are compared to determine the degree of distortion suffered by the test signal due to the communications system
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