Fabrication of J79 boron/aluminum compressor blades

A total of 81 boron/aluminum first stage compressor blades were developed. The processing of the blades and the series designs established for various types of blade tests are described

Promoting Physical Activity in Low Income African Americans: Project LAPS

Low income African Americans are at increased risk for physical inactivity and related chronic illnesses. Thus, effective interventions are needed to address these health disparities. The current study examined the efficacy of a home-based physical activity intervention among a low income African American sample with high rates of chronic illnesses (obesity, hypertension, diabetes, high cholesterol). Participants (n=214) were randomly assigned to either the home-based physical activity intervention (self-help print materials, five monthly newsletters, two telephone counseling sessions) or an attention control condition, which promoted healthy diet. Results indicated that the intervention did not produce significantly greater increases in physical activity from baseline to six months than the control group. Lessons learned from the current study include the importance of using proactive retention strategies with low income African American participants and taking into consideration the cultural relevance of the intervention

Successor Feature Sets: Generalizing Successor Representations Across Policies

Successor-style representations have many advantages for reinforcement learning: for example, they can help an agent generalize from past experience to new goals, and they have been proposed as explanations of behavioral and neural data from human and animal learners. They also form a natural bridge between model-based and model-free RL methods: like the former they make predictions about future experiences, and like the latter they allow efficient prediction of total discounted rewards. However, successor-style representations are not optimized to generalize across policies: typically, we maintain a limited-length list of policies, and share information among them by representation learning or GPI. Successor-style representations also typically make no provision for gathering information or reasoning about latent variables. To address these limitations, we bring together ideas from predictive state representations, belief space value iteration, successor features, and convex analysis: we develop a new, general successor-style representation, together with a Bellman equation that connects multiple sources of information within this representation, including different latent states, policies, and reward functions. The new representation is highly expressive: for example, it lets us efficiently read off an optimal policy for a new reward function, or a policy that imitates a new demonstration. For this paper, we focus on exact computation of the new representation in small, known environments, since even this restricted setting offers plenty of interesting questions. Our implementation does not scale to large, unknown environments -- nor would we expect it to, since it generalizes POMDP value iteration, which is difficult to scale. However, we believe that future work will allow us to extend our ideas to approximate reasoning in large, unknown environments

Boron isotope fractionation in soils at Shale Hills CZO

Isotope fractionation of many elements can fingerprint the biogeochemical, weathering and erosion processes that govern the evolution of the Critical Zone (CZ). This study investigates boron isotope fractionation in two soil profiles developed on the same shale bedrock at Shale Hills Critical Zone Observatory. The first soil profile, located at the valley floor, is isotopically similar to the bedrock and appears to have lost boron mostly through the loss of fine particles matter (clays) with no isotopic fractionation. The second soil profile, located at the ridge top appears to be more depleted in boron concentration and isotopically fractionated toward lower values, as expected from mineral dissolution followed by adsorption/co-precipitation processes

Boron isotope fractionation in soils at Shale Hills CZO

Isotope fractionation of many elements can fingerprint the biogeochemical, weathering and erosion processes that govern the evolution of the Critical Zone (CZ). This study investigates boron isotope fractionation in two soil profiles developed on the same shale bedrock at Shale Hills Critical Zone Observatory. The first soil profile, located at the valley floor, is isotopically similar to the bedrock and appears to have lost boron mostly through the loss of fine particles matter (clays) with no isotopic fractionation. The second soil profile, located at the ridge top appears to be more depleted in boron concentration and isotopically fractionated toward lower values, as expected from mineral dissolution followed by adsorption/co-precipitation processes

Reading Renaissance Teacher Intervention Strategies for Student Success: An Action Research Study

Helping children to become better readers is a tremendous responsibility faced by educators today. With students of varying abilities, reaching each child requires training, time, and dedication. The goal of this study was to improve the quality and quantity of the teacher/student relationship component of the Reading Renaissance program, which is the core-reading program in the elementary school in which I work. Consideration was given to teacher intervention strategies that were in use as well as those strategies that both teachers and students identified as effective. Staff development sessions were provided and through surveys, observations, and focus group sessions, third grade students and teachers demonstrated that participation in specific, planned staff development could be successful for changing reading instruction. Time limits of the study made it impractical to measure student reading growth

Translational methods for quantitative prediction of metabolic herbal product-drug interactions: case study with milk thistle

The misperception that herbal products are safe has perpetuated multibillion dollar sales of these products, exposing the public to potentially harmful herb-drug interactions when constituents in the herbal supplement inhibit drug metabolizing enzymes. Regulation of herbal products is not as rigorous as drug products. Consequently, evaluation of inhibitory properties of an herbal product typically is not requested before marketing. Traditional drug-drug interaction evaluation methods often are inadequate to evaluate herbal product interaction liability due to the mixture of bioactive constituents, high inherent variability between batches and manufacturers, and limited pharmacokinetic knowledge of constituents. Milk thistle was selected as an exemplar herbal product due to high usage rates in patient populations, particularly the hepatically-impaired; availability of isolated, purified constituents; and disparate effects between previous clinical interaction studies. Initial screens of inhibitory activity against the clinically relevant drug metabolizing enzymes, cytochrome P450 (CYP) 2C9 and CYP3A4, prioritized milk thistle constituents for further evaluation. The main constituents, silybin A and silybin B, inhibited CYP2C9 in a reversible manner (Ki, 10 and 4.8 μM, respectively) and CYP3A4 in an irreversible manner (KI, 110 and 89 μM, respectively). Incorporation of these in vitro kinetic parameters into a physiologically based pharmacokinetic (PBPK) model facilitated predictions of the interaction liability of milk thistle administration with FDA-recommended probe substrates of CYP2C9 (warfarin) and CYP3A4 (midazolam). Administration of large doses of the milk thistle product silibinin (1440 mg/day) was predicted to increase the peak concentration and systemic exposure of both warfarin and midazolam by roughly 5%. Proof-of-concept clinical evaluation of these silibinin-drug interactions confirmed the low interaction potential of the selected milk thistle product, as midazolam and warfarin exposure was increased modestly (9 and 13%, respectively). This mechanistic modeling and simulation approach facilitated prospective evaluation of interactions between a well-characterized herbal product and two widely used and clinically relevant probe substrates. This framework could be applied to other herbal products to predict the magnitude and likelihood of interactions with conventional drugs, guide pharmacotherapeutic decisions, and improve patient care.Doctor of Philosoph

A Comparison of Radical Perineal, Radical Retropubic, and Robot-Assisted Laparoscopic Prostatectomies in a Single Surgeon Series

Objective. We sought to compare positive surgical margin rates (PSM), estimated blood loss (EBL), and quality of life outcomes (QOL) among perineal (RPP), retropubic (RRP), and robot-assisted laparoscopic (RALP) prostatectomies. Methods. Records from 463 consecutive men undergoing RPP (92), RRP (180), or RALP (191) for clinically localized prostate cancer were retrospectively reviewed. Age, percent tumor volume, Gleason score, stage, EBL, PSM, and QOL using the expanded prostate cancer index composite (EPIC) were compared. Results. PSM were similar when adjusted for stage, grade, and volume. EBL was significantly less in the RALP (189 ml) group compared to both RPP (475 ml) and RRP (999 ml) groups. When corrected for nerve sparing, there were no differences in erectile function and sexual function amongst the three groups. Urinary summary and pad usage scores showed no significant differences. Conclusion. RPP, RRP, and RALP offer similar surgical and QOL outcomes. RALP and RPP demonstrate less EBL compared to RRP

Pinyon pine mortality alters communities of ground-dwelling arthropods

We documented the effect of drought-induced mortality of pinyon pine (Pinus edulis Engelm.) on communities of ground-dwelling arthropods. Tree mortality alters microhabitats utilized by ground-dwelling arthropods by increasing solar radiation, dead woody debris, and understory vegetation. Our major objectives were to determine (1) whether there were changes in community composition, species richness, and abundance of ground-dwelling arthropods associated with pinyon mortality and (2) whether specific habitat characteristics and microhabitats accounted for these changes. We predicted shifts in community composition and increases in arthropod diversity and abundance due to the presumed increased complexity of microhabitats from both standing dead and fallen dead trees. We found significant differences in arthropod community composition between high and low pinyon mortality environments, despite no differences in arthropod abundance or richness. Overall, 22% (51 taxa) of the arthropod community were identified as being indicators of either high or low mortality. Our study corroborates other research indicating that arthropods are responsive to even moderate disturbance events leading to changes in the environment. These arthropod responses can be explained in part due to the increase in woody debris and reduced canopy cover created by tree mortality

Mindfulness meditation targets transdiagnostic symptoms implicated in stress-related disorders: Understanding relationships between changes in mindfulness, sleep quality, and physical symptoms

Mindfulness-Based Stress Reduction (MBSR) is an 8-week meditation program known to improve anxiety, depression, and psychological well-being. Other health-related effects, such as sleep quality, are less well established, as are the psychological processes associated with therapeutic change. This prospective, observational study (n=213) aimed to determine whether perseverative cognition, indicated by rumination and intrusive thoughts, and emotion regulation, measured by avoidance, thought suppression, emotion suppression, and cognitive reappraisal, partly accounted for the hypothesized relationship between changes in mindfulness and two health-related outcomes: sleep quality and stress-related physical symptoms. As expected, increased mindfulness following the MBSR program was directly correlated with decreased sleep disturbance (r=-0.21, p=0.004) and decreased stress-related physical symptoms (r=-0.38, p<0.001). Partial correlations revealed that pre-post changes in rumination, unwanted intrusive thoughts, thought suppression, experiential avoidance, emotion suppression, and cognitive reappraisal each uniquely accounted for up to 32% of the correlation between the change in mindfulness and change in sleep disturbance and up to 30% of the correlation between the change in mindfulness and change in stress-related physical symptoms. Results suggest that the stress-reducing effects of MBSR are due, in part, to improvements in perseverative cognition and emotion regulation, two “transdiagnostic” mental processes that cut across stress-related disorders