Centers for the commercial development of space

In 1985, NASA initiated an innovative effort called Centers for the Commercial Development of Space (CCDS). The CCDS program was designed to increase private-sector interest and investment in space-related activities, while encouraging U.S. economic leadership and stimulating advances in promising areas of research and development. Research conducted in the Centers handling the following areas is summarized: materials processing; life sciences; remote sensing; automation and robotics; space propulsion; space structures and materials; and space power

SNA and SNB Angles in a Population of Nubian Schoolchildren

The descriptive statistics for the sella-nasion-A Point (SNA) and sella-nasion-B point (SNB) angles computed from a sample of Nubian schoolchildren are presented, by age and sex, and compared with the analogous statistics for American Caucasian schoolchildren .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67163/2/10.1177_00220345750540041101.pd

From the Forest to the River: Citizens\u27 Views of Stakeholder Engagement

Since the early 1990s collaboration and consensus processes have become associated with success in the environmental policy and natural resource policy arenas. Interest in collaboration and consensus processes have emerged, in part, out of a frustration with more conventional efforts used to involve stakeholders, to work though conflicts, and to make decisions in the environmental and natural resource policy arenas. Collaboration and consensus processes, when designed well and applied appropriately, provide opportunities for meaningful stakeholder engagement. This essay features aspects of two government-led or agency-based (Koontz et al. 2004; Moore and Koontz 2003) planning efforts that consider collaboration and citizens/stakeholder engagement. Both projects, a forest management plan revision on the Allegheny National Forest in Pennsylvania, and a regional sediment management planning effort at the mouth of the Columbia River in the Pacific Northwest, have considered a Collaborative Learning (CL) approach (Daniels and Walker 2001) for stakeholder involvement. As part of these CL applications, citizens/stakeholders have been asked for their views of the kind of participation processes they value and how they prefer to be involved. This essay presents a summary of citizens\u27 ideas. In doing so, it addresses the question: How do stakeholders want to be engaged in agency-led planning efforts? Data reveal that stakeholders prefer active engagement, access to information and events, and clearly defined decision space. Prior to presenting the project data germane to this question, the paper highlights the trinity of voice and Collaborative Learning

Was the M_w 7.5 1952 Kern County, California, earthquake induced (or triggered)?

Several recent studies have presented evidence that significant induced earthquakes occurred in a number of oil-producing regions during the early and mid-twentieth century related to either production or wastewater injection. We consider whether the 21 July 1952 M_w 7.5 Kern County earthquake might have been induced by production in the Wheeler Ridge oil field. The mainshock, which was not preceded by any significant foreshocks, occurred 98 days after the initial production of oil in Eocene strata at depths reaching 3 km, within ~1 km of the White Wolf fault (WWF). Based on this spatial and temporal proximity, we explore a potential causal relationship between the earthquake and oil production. While production would have normally be expected to have reduced pore pressure, inhibiting failure on the WWF, we present an analytical model based on industry stratigraphic data and best estimates of parameters whereby an impermeable splay fault adjacent to the main WWF could plausibly have blocked direct pore pressure effects, allowing the poroelastic stress change associated with production to destabilize the WWF, promoting initial failure. This proof-of-concept model can also account for the 98-day delay between the onset of production and the earthquake. While the earthquake clearly released stored tectonic stress, any initial perturbation on or near a major fault system can trigger a larger rupture. Our proposed mechanism provides an explanation for why significant earthquakes are not commonly induced by production in proximity to major faults

The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox

Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The electronic structures, phonon modes, and electron phonon coupling parameters are calculated for two oxygen-ordered MgB2 compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2. We find that the density of states for both Mg2B3Ox structures show very good agreement with EELS, indicating that they are excellent candidates to explain the observed coherent oxygen precipitates. Incorporation of oxygen reduces the transition temperature and gives calculated TC values of 18.3 K and 1.6 K for Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR

Agents of Change: African American Contributions to Writing Centers

African Americans and their contributions to our field’s first pedagogical models and operational structures are absent from writing center histories. This archival research invokes their presence by recounting the stories of five African American innovators—Bess Bolden “B. B.” Walcott, Coragreene Johnstone, Anne Cooke, Hugh Gloster, and Percival Bertrand “Bert” Phillips—spanning four decades at three historically Black colleges and universities (HBCUs). Their stories invite an expansive understanding of writing center work, moving beyond a focus on traditional tutoring and strictly alphabetic literacies and into “strategic literacies”—the survival skills needed to stand up for oneself and one’s community in the face of dangerous times and violently racist places. The writing center leaders described here saw writing as a tool to be used in concert with embodied performances for expression and survival to advance struggles for labor equity, legal justice, and civil rights. This conception of writing center work springs from sites of research such as HBCU archives and popular Black press archives that are less often examined by dominant disciplinary histories. From those sites, a timeline of African American writing center administrators emerges that spurs further research of these under-studied figures, who together constitute a remarkable legacy. Keywords: writing center studies, historically Black colleges and universities, composition studies history, higher educatio

Effects of 5 Different Finger Rest Positions on Arm Muscle Activity During Scaling by Dental Hygiene Students

Purpose. This study was conducted to determine the effects of 5 different finger rest positions: opposite arch, standard intraoral, basic extraoral, cross arch, and finger on finger on the muscle activity of 4 forearm muscles (extensor carpi radialis longus, flexor carpi ulnaris, biceps brachii, and pronator teres) during a simulated periodontal scaling experience. Methods. A convenience sample of 32 consenting senior dental hygiene students who met inclusion criteria participated. Using a 4 x 5 counter-balanced research design, each participant used a Gracey 11/12 curet to scale one cc of artificial calculus from first permanent molar typodont teeth (#3,14,19,30). Five different typodonts were set up for each participant with fulcrums randomly assigned for use on each typodont. While scaling, the participant’s muscle activity was measured by surface electromyography. Two-way analysis of variance with repeated measures was used to determine if significant differences existed in the amount of muscle activity generated with each fulcrum. Results. Results revealed no statistically significant interaction effect between area of the mouth scaled, muscle activity, and fulcrum used. Similar muscle activity was produced throughout the mouth regardless of the fulcrum used. The upper right quadrant produced the most muscle activity (p= 0.0101) and the lower left quadrant produced the least (p=\u3c .0001). When comparing the overall muscle activity generated with each fulcrum, only the cross arch fulcrum when compared to the opposite fulcrum produced statistically significant results (p=0.0110). Conclusions. Based on the results, similar muscle activity is produced when using any of the 5 fulcrums in each quadrant of the mouth. Clinicians appear to experience minimal ergonomic advantage in terms of fulcrums used and area of the mouth scaled during a simulated scaling experience

Combinations of Maternal KIR and Fetal HLA-C Genes Influence the Risk of Preeclampsia and Reproductive Success

Preeclampsia is a serious complication of pregnancy in which the fetus receives an inadequate supply of blood due to failure of trophoblast invasion. There is evidence that the condition has an immunological basis. The only known polymorphic histocompatibility antigens on the fetal trophoblast are HLA-C molecules. We tested the idea that recognition of these molecules by killer immunoglobulin receptors (KIRs) on maternal decidual NK cells is a key factor in the development of preeclampsia. Striking differences were observed when these polymorphic ligand: receptor pairs were considered in combination. Mothers lacking most or all activating KIR (AA genotype) when the fetus possessed HLA-C belonging to the HLA-C2 group were at a greatly increased risk of preeclampsia. This was true even if the mother herself also had HLA-C2, indicating that neither nonself nor missing-self discrimination was operative. Thus, this interaction between maternal KIR and trophoblast appears not to have an immune function, but instead plays a physiological role related to placental development. Different human populations have a reciprocal relationship between AA frequency and HLA-C2 frequency, suggesting selection against this combination. In light of our findings, reproductive success may have been a factor in the evolution and maintenance of human HLA-C and KIR polymorphisms