How Constraints Affect Content: The Case of Twitter's Switch from 140 to 280 Characters

It is often said that constraints affect creative production, both in terms of form and quality. Online social media platforms frequently impose constraints on the content that users can produce, limiting the range of possible contributions. Do these restrictions tend to push creators towards producing more or less successful content? How do creators adapt their contributions to fit the limits imposed by social media platforms? To answer these questions, we conduct an observational study of a recent event: on November 7, 2017, Twitter changed the maximum allowable length of a tweet from 140 to 280 characters, thereby significantly altering its signature constraint. In the first study of this switch, we compare tweets with nearly or exactly 140 characters before the change to tweets of the same length posted after the change. This setup enables us to characterize how users alter their tweets to fit the constraint and how this affects their tweets' success. We find that in response to a length constraint, users write more tersely, use more abbreviations and contracted forms, and use fewer definite articles. Also, although in general tweet success increases with length, we find initial evidence that tweets made to fit the 140-character constraint tend to be more successful than similar-length tweets written when the constraint was removed, suggesting that the length constraint improved tweet quality.Comment: To appear in the Proceedings of AAAI ICWSM 201

Experiences Of Undergraduate Reentry Males During Times Of Perceived Psychological Stress

The research question that served as the basic guide for inquiry in this study was: How do undergraduate reentry males navigate through academic coursework, especially during times of perceived psychological stress? Using a semi-structured interview technique, eight Caucasian undergraduate male students, ages 43 – 52, were interviewed. Findings revealed three major themes: a) the psychological stress encountered did not emanate so much from the academic experience as it did from personal struggles, relationship and/or family obligations, and/or work demands; b) when discussing strategies utilized to facilitate engagement in academic coursework, the men reported use of goal setting/planning and seeking social assistance to regulate the academic environment to some extent and compartmentalization as a way of being able to focus on the learning task at hand; and c) for some men there was a perceived difference in self over time with regard to academic coursework. While it has been suggested (Home, 1997; Senter & Senter, 1998) that returning female students may experience more stress than do returning males, findings from this study have shown that some reentry men, report similar needs and concerns related to life demands while engaged in academic coursework

The Experiences of Undergraduate Reentry Collegiate Males During Times Of Perceived Psychological Stress

While adult education can occur in a variety of settings, the number of adults returning to higher education has increased over the years. Because these adults tend to be older than the “typical” college student, they are frequently categorized as “nontraditional” students. Many nontraditional students struggle to manage the student role as it interacts with other life roles. Even though multiple roles provide the heterogeneity of experience that adult learners bring to higher education classrooms, they can add to the daily stress experience by returning students. Stress has been reported to be a major barrier faced by adults returning to school. However, at present very little is known about the ways in which adult learners navigate the challenges of coursework, especially during times of perceived stress. Stressors experienced by returning women have been explored though little has been done to investigate issues and concerns of men returning to academia in their adult years. Therefore, the purpose of this study was to understand the experiences of nontraditional, reentry, undergraduate male students engaged in academic coursework during times of reported psychological stress. The research question that served as the guide for inquiry was: How do undergraduate, reentry male, college students navigate through academic coursework, especially during times of perceived psychological stress? Men between the ages of 43 and 54 were interviewed using a semi-structured interview technique. Major themes that emerged were: 1) the occurrence of stress while engaged in coursework; 2) perspectives on academic coursework; and 3) strategies utilized to facilitate engagement in academic coursework. Findings indicated that the stress experienced did not emanate so much from the academic coursework as it did from personal struggles, relationships and/or family obligations, and work demands. Several participants spoke to a difference in self over time with regard to engagement in collegiate studies as well as a difference in their perception of learning. Strategies utilized to navigate through academic coursework were activated to maximize the potential for academic success while not adding to the stress being experienced. Recommendations for theory and practice are offered

Soft Spin Wave Near nu=1: Evidence for a Magnetic Instability in Skyrmion Systems

The ground state of the two dimensional electron gas near $\nu$=1 is investigated by inelastic light scattering measurements carried down to very low temperatures. Away from $\nu$=1, the ferromagnetic spin wave collapses and a new low-energy spin wave emerges below the Zeeman gap. The emergent spin wave shows soft behavior as its energy increases with temperature and reaches the Zeeman energy for temperatures above 2 K. The observed softening indicates an instability of the two dimensional electron gas towards a magnetic order that breaks spin rotational symmetry. We discuss our findings in light of the possible existence of a Skyrme crystal.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let

Optimising STEM education in WA schools

Education in science, technology, engineering and mathematics (STEM) is a powerful and productive driving force for economic growth. A strong STEM education system provides the essential underpinning of an innovative and scientifically literate culture that: develops the capabilities for individuals to function effectively within a science and technology based society; provides an ever widening range of career opportunities; and, builds the productive capacity required to drive a prosperous economy and enhanced well-being in an increasingly competitive world. The STEM education pipeline begins in our schools, therefore there is widespread and deep concern about the unsatisfactory status of STEM education in WA primary and secondary schools. This concern is also evident at the national level where Professor Ian Chubb, Australia’s Chief Scientist, has made a strong call for action in Australia to increase the number of STEM graduates to drive innovation and economic growth. The imperative for WA is to support the development of our school students’ STEM capabilities and interest in further education and careers in STEM

Titan Haze

The Titan haze exerts a dominating influence on surface visibility and atmospheric radiative heating at optical and near-infrared wavelengths and our desire to understand surface composition and atmospheric dynamics provides a strong motivation to study the properties of the haze. Prior to the Cassini/Huygens missions the haze was known to be global in extent, with a hemispheric contrast asymmetry, with a complicated structure in the polar vortex region poleward of about 55 deg latitude, and with a distinct layer near 370 km altitude outside of the polar vortex at the time of the Voyager 2 flyby. The haze particles measured by the Pioneer and Voyager spacecraft were both highly polarizing and strongly forward scattering, a combination that seems to require an aggregation of small (several tens of nm radius) primary particles. These same properties were seen in the Cassini orbiter and Huygens Probe data. The most extensive set of optical measurements were made inside the atmosphere by the Descent Imager/Spectral Radiometer (DISR) instrument on the Huygens Probe. At the probe location as determined by the DISR measurements the average haze particle contained about 3000 primary particles whose radius is about 40 nm. Three distinct vertical regions were seen in the DISR data with differing particle properties. Refractive indices of the particles in the main haze layer resemble those reported by Khare et al. between O.3S and about 0.7 micron but are more absorbing than the Khare et al. results between 0.7 micron and the long-wavelength limit of the DISR spectra at 1.6 micron. These and other results are described by Tomasko et al., and a broader summary of results was given by Tomasko and West,. New data continue to stream in from the Cassini spacecraft. New data analyses and new laboratory and model results continue to move the field forward. Titan's 'detached' haze layer suffered a dramatic drop in altitude near equinox in 2009 with implications for the circulation and seasonal change in the stratosphere. The book chapter associated with this talk will also present new material on thermal-infrared data analysis and on new developments in laboratory work and haze microphysical modeling

Communicating hands: ERPs elicited by meaningful symbolic hand postures.

Meaningful and meaningless hand postures were presented to subjects who had to carry out a semantic discrimination task while electrical brain responses were recorded. Both meaningful and control sets of hand postures were matched as closely as possible. The ERPs elicited by meaningless hand postures showed an anteriorly distributed N300 and a centro-posteriorly distributed N400 component. The N300 probably reflects picture-specific processes, whereas the N400-effect probably reflects processing in an amodal semantic network. The scalp-distribution of the N400-effect, which is more posterior than usually reported in picture processing, suggests that the semantic representations of the concepts expressed by meaningful hand postures have similar properties to those of abstract words

Galaxy Alignments in Very X-ray Luminous Clusters at z>0.5

We present the results of a search for galaxy alignments in 12 galaxy clusters at z>0.5, a statistically complete subset of the very X-ray luminous clusters from the MAssive Cluster Survey (MACS). Using high-quality images taken with the Hubble Space Telescope (HST) that render measurement errors negligible, we find no radial galaxy alignments within 500 kpc of the cluster centres for a sample of 545 spectroscopically confirmed cluster members. A mild, but statistically insignificant trend favouring radial alignments is observed within a radius of 200 kpc and traced to galaxies on the cluster red sequence. Our results for massive clusters at z>0.5 are in stark contrast to the findings of previous studies which find highly significant radial alignments of galaxies in nearby clusters at z~0.1 out to at least half the virial radius using imaging data from the SDSS. The discrepancy becomes even more startling if radial alignment becomes more prevalent at decreasing clustercentric distance, as suggested by both our and previous work. We investigate and discuss potential causes for the disparity between our findings based on HST images of clusters at z>0.5 and those obtained using groundbased images of systems at z~0.1. We conclude that the most likely explanation is either dramatic evolution with redshift (in the sense that radial alignments are less pronounced in dynamically younger systems) or the presence of systematic biases in the analysis of SDSS imaging data that cause at least partly spurious alignment signals.Comment: 10 pages, 11 figures, and 1 table. Accepted for publication in MNRA