Drilling and Digging Techniques for the Early Lunar Outpost

The theme of this workshop is lunar resource assessment. Topics include identification, quantification, and location of useful elements on and below the lunar surface. The objective of this paper is to look at another side of the issue--how to remove soil from the stiff lunar-soil matrix once useful deposits are located. The goal of this paper is to cause those who think that digging or excavating on the Moon is a trivial problem to rethink the reasons for their opinions. Another goal is to encourage them to view total reliance upon terrestrial heuristics with suspicion. This paper will focus primarily upon digging

Theoretical flow characteristics of inlets for tilting-nacelle VTOL aircraft

The results of a theoretical investigation of geometric variables for lift-cruise-fan, tilting nacelle inlets operating at high incidence angles are presented. These geometric variables are investigated for their effects on surface static to free stream pressure ratio, and the separation parameters of maximum to diffuser exit surface velocity ratio and maximum surface Mach number for low speed operating conditions. The geometric parameters varied were the internal lip contraction ratio, external forebody to diffuser exit diameter ratio external forebody length to diameter ratio and internal lip major to minor axis ratio

Aerodynamic characteristics of a small-scale straight and swept-back wing with knee-blown jet flaps

Two sting-mounted, 50.8 cm (20 in.) span, knee-blown, jet-flap models were tested in a large (2.1- by 2.5-m (7- by 10-ft) subsonic wind tunnel. A straight- and swept-wing model were tested with fixed flap deflection with various combinations of full-span leading-edge slats. The swept-wing model was also tested with wing tip extensions. Data were taken at angles-of-attack between 0 deg and 40 deg, at dynamic pressures between 143.6 N/sq m (3 lb/sq ft) and 239.4 N/sq m (5 lb/sq ft), and at Reynolds numbers (based on wing chord) ranging from 100,000 to 132,000. Jet flap momentum blowing coefficients up to 10 were used. Lift, drag, and pitching-moment coefficients, and exit flow profiles for the flap blowing are presented in graphical form without analysis

Interfirm Structure and Buyer-Salesperson Behavior Impact on Relationship Outcomes

The individual level interaction between the buyer and salesperson can best be understood in the broader framework provided by the inter-firm relationship. Very little research has been conducted that examines both firm level and interpersonal level constructs in the context of business relationships. The primary purpose of this study is to design and test a theoretical model that examines the effect of inter-firm structure and buyer-salesperson behaviors on relationship outcomes. The results suggest that in established relationships, the external environment plays a role in determining the how buyer-seller firms structure their relationships. The way in which the relationship is structured plays an important role in determining how the buyer and salesperson interact. Both inter-firm structure and buyer-salesperson behaviors, in turn, influence buyer satisfaction

Developing students' employability in work placements

SESSION C1: Integration of theory and practice in the learning and teaching process CONTEXT Employer feedback consistently reports gaps in graduate professional capabilities. Developing graduates' work readiness is a goal of growing importance in the tertiary sector. Institutions are embedding curriculum and co- and extra-curricular activities to better develop student employability capabilities. While work placements are widely viewed as the best way to develop employability, employability learning activities in the curriculum can augment experiential learning. PURPOSE The aim of this study was to explore the question What preparation can develop student communication, networking and reflection skills before undertaking an engineering work placement? APPROACH A number of frameworks were used to guide development of new curriculum for employability. Eyler's reflective practice framework was used to enhance learning from experience, and an affordance model framework was used to scaffold learning, to prioritize learning during workshops to higher order skill development. A cultural values framework was used to guide learning about workplace culture. RESULTS A workshop was developed for students looking for a placement that focuses on the application, networking and interviewing. A second workshop was developed for students who had already sourced a placement that focuses on key workplace learning opportunities: meetings, networking and reflection on experience. CONCLUSIONS Well designed workshops can be an effective way to enhance student learning. Evaluation of outcomes and impact of the teaching innovation in employability lag interventions by several years, so longitudinal studies need to be carried out for a full evaluation

Confirmatory factor analysis of the Child Feeding Questionnaire among low-income African American families of preschool children

This study examined the factor structure for three of the Child Feeding Questionnaire (CFQ) subscales, a widely used measure of parental feeding practices, among 296 low-income parents of African American preschool children. Confirmatory factor analysis showed an overall poor fit among CFQ subscales; Restriction, Pressure to Eat, and Concern about Child Weight, (χ2, (df = 87 = 300.249, CFI = 1.00, NNFI = 1.07, RMSEA = .091). Additionally, Cronbach’s Alpha coefficients for 2 of the three subscales were below acceptable recommendations (Restriction = 0.69; Pressure to Eat = 0.58). These results suggest further psychometric clarification is needed to understand commonly reported feeding practice constructs among low-income African American mothers of preschool aged children

Confirmatory factor analysis of the Child Feeding Questionnaire among low-income African American families of preschool children

This study examined the factor structure for three of the Child Feeding Questionnaire (CFQ) subscales, a widely used measure of parental feeding practices, among 296 low-income parents of African American preschool children. Confirmatory factor analysis showed an overall poor fit among CFQ subscales; Restriction, Pressure to Eat, and Concern about Child Weight, (χ2, (df = 87 = 300.249, CFI = 1.00, NNFI = 1.07, RMSEA = .091). Additionally, Cronbach’s Alpha coefficients for 2 of the three subscales were below acceptable recommendations (Restriction = 0.69; Pressure to Eat = 0.58). These results suggest further psychometric clarification is needed to understand commonly reported feeding practice constructs among low-income African American mothers of preschool aged children

Discovery of Precursor LBV Outbursts in Two Recent Optical Transients: The Fitfully Variable Missing Links UGC 2773-OT and SN 2009ip

We present progenitor-star detections, light curves, and optical spectra of SN2009ip and the 2009 optical transient in UGC2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that both of the progenitor stars were LBVs. Their pre-outburst light curves resemble the S Doradus phases that preceded giant eruptions of eta Carinae and SN1954J (V12 in NGC2403), with intermediate progenitor luminosities. HST detections a decade before discovery indicate that the SN2009ip and U2773-OT progenitors were supergiants with likely initial masses of 50-80 Msun and \ga20 Msun, respectively. Both outbursts had spectra befitting known LBVs, although in different physical states. SN 2009ip exhibited a hot LBV spectrum with characteristic speeds of 550 km/s, plus faster material up to 5000 km/s, resembling the slow Homunculus and fast blast wave of eta Carinae. U2773-OT shows a forest of narrow absorption and emission lines comparable to that of S Dor in its cool state, plus [CaII] emission and an IR excess indicative of dust, similar to SN2008S and N300-OT. [CaII] emission is probably tied to a dusty pre-outburst environment, and not the outburst mechanism. SN2009ip and U2773-OT may provide a critical link between historical LBV eruptions, while U2773-OT may provide a link between LBVs and SN2008S and N300-OT. Future searches will uncover more examples of precursor LBV variability of this kind, providing key clues that may help unravel the instability driving LBVs.Comment: 18 pages, 13 Figures, accepted AJ. added significant material while revising after referee repor

Evidence for Diversity in Transcriptional Profiles of Single Hematopoietic Stem Cells

Hematopoietic stem cells replenish all the cells of the blood throughout the lifetime of an animal. Although thousands of stem cells reside in the bone marrow, only a few contribute to blood production at any given time. Nothing is known about the differences between individual stem cells that dictate their particular state of activation readiness. To examine such differences between individual stem cells, we determined the global gene expression profile of 12 single stem cells using microarrays. We showed that at least half of the genetic expression variability between 12 single cells profiled was due to biological variation in 44% of the genes analyzed. We also identified specific genes with high biological variance that are candidates for influencing the state of readiness of individual hematopoietic stem cells, and confirmed the variability of a subset of these genes using single-cell real-time PCR. Because apparent variation of some genes is likely due to technical factors, we estimated the degree of biological versus technical variation for each gene using identical RNA samples containing an RNA amount equivalent to that of single cells. This enabled us to identify a large cohort of genes with low technical variability whose expression can be reliably measured on the arrays at the single-cell level. These data have established that gene expression of individual stem cells varies widely, despite extremely high phenotypic homogeneity. Some of this variation is in key regulators of stem cell activity, which could account for the differential responses of particular stem cells to exogenous stimuli. The capacity to accurately interrogate individual cells for global gene expression will facilitate a systems approach to biological processes at a single-cell level

Modulation of eDNA Release and Degradation Affects Staphylococcus aureus Biofilm Maturation

Recent studies have demonstrated a role for Staphylococcus aureus cidA-mediated cell lysis and genomic DNA release in biofilm adherence. The current study extends these findings by examining both temporal and additional genetic factors involved in the control of genomic DNA release and degradation during biofilm maturation. Cell lysis and DNA release were found to be critical for biofilm attachment during the initial stages of development and the released DNA (eDNA) remained an important matrix component during biofilm maturation. This study also revealed that an lrgAB mutant exhibits increased biofilm adherence and matrix-associated eDNA consistent with its proposed role as an inhibitor of cidA-mediated lysis. In flow-cell assays, both cid and lrg mutations had dramatic effects on biofilm maturation and tower formation. Finally, staphylococcal thermonuclease was shown to be involved in biofilm development as a nuc mutant formed a thicker biofilm containing increased levels of matrix-associated eDNA. Together, these findings suggest a model in which the opposing activities of the cid and lrg gene products control cell lysis and genomic DNA release during biofilm development, while staphylococcal thermonuclease functions to degrade the eDNA, possibly as a means to promote biofilm dispersal