Sensor Sleeve: Sensing Affective Gestures

We describe the use of textile sensors mounted in a garment sleeve to detect affective gestures. The `Sensor Sleeve' is part of a larger project to explore the role of affect in communications. Pressure activated, capacitive and elasto-resistive sensors are investigated and their relative merits reported on. An implemented application is outlined in which a cellphone receives messages derived from the sleeve's sensors using a Bluetooth interface, and relays the signals as text messages to the user's nominated partner

A Reading Lesson Observation Framework for Elementary Teachers, Principals, and Literacy Supervisors

Henk et al present a framework which will provide reference points for assessment and help refine instructional practices in reading

The Writing Observation Framework: A Guide for Refining and Validating Writing Instruction

The Writing Observation Framework (WOF) is a new tool for enhancing writing instruction in schools. The WOF organizes principles of writing instruction In a way that improves the evaluation of teachers\u27 writing practices, encourages a shared philosophy of the writing process and its instruction, and assists schools in demonstrating the integrity of their writing programs

Phase transition in a 2-dimensional Heisenberg model

We investigate the two-dimensional classical Heisenberg model with a nonlinear nearest-neighbor interaction V(s,s')=2K[(1+s.s')/2 ]^p. The analogous nonlinear interaction for the XY model was introduced by Domany, Schick, and Swendsen, who find that for large p the Kosterlitz-Thouless transition is preempted by a first-order transition. Here we show that, whereas the standard (p=1) Heisenberg model has no phase transition, for large enough p a first-order transition appears. Both phases have only short range order, but with a correlation length that jumps at the transition.Comment: 6 pages, 5 encapsulated postscript figures; to appear in Physical Review Letter

Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators

Topological insulators are a new phase of matter that exhibits exotic surface electronic properties. Determining the spin texture of this class of material is of paramount importance for both fundamental understanding of its topological order and future spin-based applications. In this article, we review the recent experimental and theoretical studies on the differential coupling of left- versus right-circularly polarized light to the topological surface states in angle-resolved photoemission spectroscopy. These studies have shown that the polarization of light and the experimental geometry plays a very important role in both photocurrent intensity and spin polarization of photoelectrons emitted from the topological surface states. A general photoemission matrix element calculation with spin-orbit coupling can quantitatively explain the observations and is also applicable to topologically trivial systems. These experimental and theoretical investigations suggest that optical excitation with circularly polarized light is a promising route towards mapping the spin-orbit texture and manipulating the spin orientation in topological and other spin-orbit coupled materials.Comment: submitted to Phys. Status Solidi RR

How well can we determine cluster mass profiles from weak lensing?

Weak gravitational lensing provides a direct way to study the mass distribution of clusters of galaxies at large radii. Unfortunately, large scale structure along the line of sight also contributes to the lensing signal, and consequently affects the measurements. We quantify the effect of distant uncorrelated large scale structure on the inferred mass profile of clusters as measured from weak lensing. We consider NFW profiles, and find that large scale structure is a major source of uncertainty for most practical situations, when a model, with the mass M_200 and the concentration parameter c as free parameters, is fit to the observations. We find that the best constraints are found for clusters at intermediate redshifts (z~0.3). For a cluster at z=0.3, optimal results are obtained when the lensing signal is measured out to 10-15 arcminutes. Measurements at larger radii do not improve the accuracy with which the profile can be determined, contrary to what is expected when the contribution from large scale structure is ignored. The true uncertainties in M_200 and the concentration parameter c are ~2 times larger than when distant large scale structure is not included in the error budget.Comment: submitted to MNRA

Environmental Forcings of Paleogene Southern Ocean Dinoflagellate Biogeography

Despite warm polar climates and low meridional temperature gradients, a number of different high-latitude plankton assemblages were, to varying extents, dominated by endemic species during most of the Paleogene. To better understand the evolution of Paleogene plankton endemism in the high southern latitudes, we investigate the spatiotemporal distribution of the fossil remains of dinoflagellates, i.e., organic-walled cysts (dinocysts), and their response to changes in regional sea surface temperature (SST). We show that Paleocene and early Eocene (∼65–50 Ma) Southern Ocean dinocyst assemblages were largely cosmopolitan in nature but that a distinct switch from cosmopolitan-dominated to endemic-dominated assemblages (the so-called “transantarctic flora”) occurred around the early-middle Eocene boundary (∼50 Ma). The spatial distribution and relative abundance patterns of this transantarctic flora correspond well with surface water circulation patterns as reconstructed through general circulation model experiments throughout the Eocene. We quantitatively compare dinocyst assemblages with previously published TEX86–based SST reconstructions through the early and middle Eocene from a key locality in the southwest Pacific Ocean, ODP Leg 189 Site 1172 on the East Tasman Plateau. We conclude that the middle Eocene onset of the proliferation of the transantarctic flora is not linearly correlated with regional SST records and that only after the transantarctic flora became fully established later in the middle Eocene, possibly triggered by large-scale changes in surface-ocean nutrient availability, were abundances of endemic dinocysts modulated by regional SST variations

The Re-Establishment of Desiccation Tolerance in Germinated Arabidopsis thaliana Seeds and Its Associated Transcriptome

The combination of robust physiological models with “omics” studies holds promise for the discovery of genes and pathways linked to how organisms deal with drying. Here we used a transcriptomics approach in combination with an in vivo physiological model of re-establishment of desiccation tolerance (DT) in Arabidopsis thaliana seeds. We show that the incubation of desiccation sensitive (DS) germinated Arabidopsis seeds in a polyethylene glycol (PEG) solution re-induces the mechanisms necessary for expression of DT. Based on a SNP-tile array gene expression profile, our data indicates that the re-establishment of DT, in this system, is related to a programmed reversion from a metabolic active to a quiescent state similar to prior to germination. Our findings show that transcripts of germinated seeds after the PEG-treatment are dominated by those encoding LEA, seed storage and dormancy related proteins. On the other hand, a massive repression of genes belonging to many other classes such as photosynthesis, cell wall modification and energy metabolism occurs in parallel. Furthermore, comparison with a similar system for Medicago truncatula reveals a significant overlap between the two transcriptomes. Such overlap may highlight core mechanisms and key regulators of the trait DT. Taking into account the availability of the many genetic and molecular resources for Arabidopsis, the described system may prove useful for unraveling DT in higher plants