Target and Projectile: Material Effects on Crater Excavation and Growth

Scaling relationships allow the initial conditions of an impact to be related to the excavation flow and final crater size and have proven useful in understanding the various processes that lead to the formation of a planetary-scale crater. In addition, they can be examined and tested through laboratory experiments in which the initial conditions of the impact are known and ejecta kinematics and final crater morphometry are measured directly. Current scaling relationships are based on a point-source assumption and treat the target material as a continuous medium; however, in planetary-scale impacts, this may not always be the case. Fragments buried in a megaregolith, for instance, could easily approach or exceed the dimensions of the impactor; rubble-pile asteroids could present similar, if not greater, structural complexity. Experiments allow exploration into the effects of target material properties and projectile deformation style on crater excavation and dimensions. This contribution examines two of these properties: (1) the deformation style of the projectile, ductile (aluminum) or brittle (soda-lime glass) and (2) the grain size of the target material, 0.5-1 mm vs. 1-3 mm sand

The Case for Social Enterprise

The bottom of the pyramid (BoP) approach popularised Prahalad (2004) as well as other writers such as Hart (2005) and London (2007), calls for the engagement of business with the bottom segment of the global income pyramid, and has attracted considerable attention and debate. The BoP lens is applied chiefly to communities experiencing ‘extreme poverty’ in low income countries with little reference to the growing number of people living in ‘relative poverty’ in high income countries. For the purpose of stimulating academic debate this paper seeks to explore the role of the so-called fourth sector, a domain for hybrid business ventures of social (and, in the case of this paper, Indigenous) entrepreneurs, at what we refer to as ‘the bottom at the top of the income pyramid’ in Australia. Using examples of Indigenous and social entrepreneurship within disadvantaged communities, we seek to highlight the scope for fourth sector enterprises at the lower end of the income spectrum within developed countries. It is suggested that the business models found within the fourth sector offer promising, alternative approaches for addressing the economic as well as social and cultural needs of those living on the fringes of today’s increasingly fragmented high-income societies

Data Quality Procedures in Survey Research: An Analysis and Framework for Doctoral Program Curricula

To ensure validity in survey research, it is imperative that we properly educate doctoral students on best practices in data quality procedures. A 14-year analysis of 679 studies in the AIS “Basket of 8” journals noted undercommunication in the most pertinent procedures, consistent across journals and time. Given recent calls for improvements in data transparency, scholars must be educated on the importance and methods for ensuring data quality. Thus, to guide the education of doctoral students, we present a “5-C Framework\u27\u27 of data quality procedures derived from a wide-ranging literature review. Additionally, we describe a set of guidelines regarding enacting and communicating data quality procedures in survey research

Similarity in cognitive complexity and attraction to friends and lovers: Experimental and correlational studies

Abstract OnlyTwo studies are reported examining whether similarities in cognitive complexity foster different forms of interpersonal attraction. Study 1 provided an experimental test of the hypothesis that perceivers would be more attracted to targets with similar levels of complexity than to targets with dissimilar levels of complexity. Participants read interpersonal impressions reflecting low and high levels of cognitive complexity and completed 3 assessments of attraction (social, task, and intellectual) to the source of the impressions. As predicted, there were significant interactions between perceiver complexity and target complexity such that high-complexity perceivers were more attracted to high-complexity targets than were low-complexity perceivers, whereas low-complexity perceivers were more attracted to low-complexity targets than were high-complexity perceivers. Unexpectedly, however, low-complexity perceivers were more attracted to a high-complexity target than a low-complexity target. Study 2 examined the effects of similarities in cognitive complexity on attraction among 126 pairs of dating partners. Partners having similar levels of cognitive complexity expressed significantly greater intellectual attraction to one another than partners having dissimilar levels of cognitive complexity

Board 141: Engineering Identity as a Predictor of Undergraduate Students\u27 Persistence in Engineering

Improving graduation rates of students who have selected and been admitted to engineering majors is a pivotal strategy in supporting national initiatives to increase the number of engineering graduates. Research suggests that the degree to which a student is attached to or belongs to engineering as a discipline better explains persistence-related outcomes than lack of interest and ability. As a result, identity frameworks have proven useful for furthering the understanding of engineering persistence. In this paper, we examine the relationship between undergraduate students’ engineering identity and persistence as an engineering major. As part of an ongoing NSF IUSE project, a concise five-item measure of engineering identity was developed and validated. That measure was administered to a large sample of engineering freshmen at a southwestern engineering school. Engineering identity was assessed twice, once prior to the beginning of fall semester when students had not yet taken an engineering course (Time 1) and once at the end of fall semester after completing introductory engineering courses (Time 2). Persistence as an engineering major was assessed prior to the beginning of the sophomore year (Time 3). Results showed that engineering identity measured at both Time 1 (r = .09) and Time 2 (r = .22) was significantly related to persistence as an engineering major at Time 3. The paper describes the implications of these longitudinal findings, future data analyses, and the importance of engineering identity. Having a concise, validated measure of identity will be valuable for quick assessment of student engineering identity and gaining further understanding of the relationship between identity and persistence in engineering

Which comforting messages really work best? A different perspective on Lemieux and Tighe’s “receiver perspective”

Abstract OnlyThis article responds critically to a recent article by Lemieux and Tighe (Communication Research Reports, 21, 144–153, 2004) in which the authors conclude that recipients of comforting efforts prefer messages that exhibit a moderate rather than high level of person centeredness. It is argued that an erroneous assumption made by Lemieux and Tighe about the status of “receiver perspective” research on the comforting process led to faulty interpretations of the data and unwarranted conclusions about recipient preferences regarding comforting messages. Alternative interpretations of Lemieux and Tighe's data are presented; these are guided by the extensive previous research that has assessed evaluations and outcomes of comforting messages

Cotton Irrigation in the Lower Rio Grande Valley.

16 p