Benchmarking hypercube hardware and software

It was long a truism in computer systems design that balanced systems achieve the best performance. Message passing parallel processors are no different. To quantify the balance of a hypercube design, an experimental methodology was developed and the associated suite of benchmarks was applied to several existing hypercubes. The benchmark suite includes tests of both processor speed in the absence of internode communication and message transmission speed as a function of communication patterns

Estimating moose population parameters from aerial surveys

Successful moose management depends on knowledge of population dynamics. The principal parameters required are size, rate of change, recruitment, sex composition, and mortality. Moose management in Alaska has been severely hampered by the lack of good estimates of these parameters, and unfortunately, this lack contributed to the decline of many Alaskan moose populations during the 1970s (e.g., Gasaway et al. 1983). The problems were: (1) population size not adequately estimated, (2) rapid rates of decline not acknowledged until populations were low, (3) meaningful recruitment rates were not available in the absence of good population estimates, and (4) calf and adult mortality rates were grossly underestimated. Frustration of moose managers working with inadequate data led to development of aerial survey procedures that yield minimally biased, sufficiently precise estimates of population parameters for most Alaskan moose management and research. This manual describes these procedures. Development of these procedures would have been impossible without the inspiration, support, advice, and criticism of many colleagues. We thank these colleagues for their contributions. Dale Haggstrom and Dave Kelleyhouse helped develop flight patterns, tested and improved early sampling designs, and as moose managers, put these procedures into routine use. Pilots Bill Lentsch and Pete Haggland were instrumental in developing and testing aerial surveying techniques. Their interest and dedication to improving moose management made them valuable allies. Statisticians Dana Thomas of the University of Alaska and W. Scott Overton of Oregon State University provided advice on variance approximations for the population estimator. Warren Ballard, Sterling Miller, SuzAnne Miller, Doug Larsen, and Wayne Kale tested procedures and provided valuable criticisms and suggestions. Jim Raymond initially programmed a portable calculator to make lengthy calculation simple, fast, and error-free. Angie Babcock, Lisa Ingalls, Vicky Leffingwell, and Laura McManus patiently typed several versions of this manual. John Coady and Oliver Burris provided continuous moral and financial support for a 3-year project that lasted 6 years. Joan Barnett, Rodney Boetje, Steven Peterson, and Wayne Regelin of the Alaska Department of Fish and Game provided helpful editorial suggestions in previous drafts. Finally, we thank referees David Anderson of the Utah Cooperative Wildlife Research Unit, Vincent Schultz of Washington State University, and James Peek, E. "Oz" Garton, and Mike Samuel of the University of Idaho whose comments and suggestions improved this manual. This project was funded by the Alaska Department of Fish and Game through Federal Aid in Wildlife Restoration Projects W-17-9 through W-22-1

Simulated fiddler-crab sediment mixing

Using a lattice-automaton model, we simulate the effects of fiddler crabs on the distribution of excess 210Pb in marsh sediments. Three previously-identified modes of bioturbation are investigated: (1) removal-and-fill, where material is excavated to the sediment-water interface and burrows, when abandoned, are subsequently filled by surface material, (2) removal-and-collapse, where the infilling occurs by collapse of the burrow walls, and (3) partial-compaction-and-collapse, where part of the excavated sediment is packed into the burrow wall and abandoned burrows subsequently collapse. These various mixing modes lead to somewhat different laterally-integrated 210Pbex profiles, which are also influenced by burrowing frequency, burrow dimensions, fraction of surface material replaced by new sediment (regeneration), and the fraction of material compacted during burial.Using parameters from a previous study in a South Carolina marsh, we find that data from low-marsh sites are best predicted by the partial-compaction-and-collapse process; this is consistent with the observation that burrow casts indicate far more material is excavated than is deposited as pellets at the sediment-water interface. The profile from the high-marsh site is best simulated by removal-and-fill mixing, with 50% regeneration of material at the sediment-water interface; this is consistent with less frequent flooding at this site.We have also calculated the exchange function for each of these mixing modes and show that they are highly asymmetric, indicating that the mixing is not diffusive. Only in the case of partialcompaction-and-collapse does the exchange function approach a diffusive form when the excavation rate decreases, i.e., the probability of compaction increases

Interactions between sea urchin grazing and prey diversity on temperate rocky reef communities

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116948/1/ecy20139471636.pd

Pain Coping Skills Training for Patients Who Catastrophize About Pain Prior to Knee Arthroplasty: A Multisite Randomized Clinical Trial

BACKGROUND: Pain catastrophizing has been identified as a prognostic indicator of poor outcome following knee arthroplasty. Interventions to address pain catastrophizing, to our knowledge, have not been tested in patients undergoing knee arthroplasty. The purpose of this study was to determine whether pain coping skills training in persons with moderate to high pain catastrophizing undergoing knee arthroplasty improves outcomes 12 months postoperatively compared with usual care or arthritis education. METHODS: A multicenter, 3-arm, single-blinded, randomized comparative effectiveness trial was performed involving 5 university-based medical centers in the United States. There were 402 randomized participants. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale, measured at baseline, 2 months, 6 months, and 12 months following the surgical procedure. RESULTS: Participants were recruited from January 2013 to June 2016. In 402 participants, 66% were women and the mean age of the participants (and standard deviation) was 63.2 ± 8.0 years. Three hundred and forty-six participants (90% of those who underwent a surgical procedure) completed a 12-month follow-up. All 3 treatment groups had large improvements in 12-month WOMAC pain scores with no significant differences (p > 0.05) among the 3 treatment arms. No differences were found between WOMAC pain scores at 12 months for the pain coping skills and arthritis education groups (adjusted mean difference, 0.3 [95% confidence interval (CI), -0.9 to 1.5]) or between the pain coping and usual-care groups (adjusted mean difference, 0.4 [95% CI, -0.7 to 1.5]). Secondary outcomes also showed no significant differences (p > 0.05) among the 3 groups. CONCLUSIONS: Among adults with pain catastrophizing undergoing knee arthroplasty, cognitive behaviorally based pain coping skills training did not confer pain or functional benefit beyond the large improvements achieved with usual surgical and postoperative care. Future research should develop interventions for the approximately 20% of patients undergoing knee arthroplasty who experience persistent function-limiting pain. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence

Let’s Play! Gamifying Engineering Ethics Education Through the Development of Competitive and Collaborative Activities

Engineering ethics is an extremely important topic that needs to be focused on more in engineering curricula, as many of the projects that engineers work on have a profound impact on society. There are many pitfalls with the traditional ways in which ethics is taught to engineering students as an abstract philosophical topic, rather than personal decision making situated in complex real contexts. The three main approaches that are used for engineering ethics include being taught by a professor outside of the engineering space, being taught late in their curriculum such as during a senior capstone project, and being taught in a short period of time as a module of another class. The downsides to these approaches are that students do not see ethics as equally important as some other topics, they do not see it consistently integrated throughout the curriculum, nor do they see ethical decisions as complex nuanced, and situated in context,. Game-based learning is a means to actively engage students in interrogating the complexities of ethical decision making. Game play can align with student learning objectives as well as improve student knowledge, behaviors, and dispositions. Our paper introduces three games that are designed to assist in the development of students’ ethical awareness and reasoning. Three engineering ethics games have been developed as the foundation for an NSF-funded project that investigates the empirical impacts of game play on ethical reasoning and decision making. Cards Against Engineering Ethics, Toxic Workplaces, and Mars: An Ethical Expedition have all been in development for the last few years. Each game targets specific ethics learning outcomes as well as different play mechanics. These outcomes include identifying the complexities of ethical dilemmas, evaluating responses to ethical situations in context, and promoting ethical discussions among peers. The time required to play each game varies, ranging from 20 minutes, to 75 minutes, to 5 minutes once a week for 15 weeks. The benefits that these games include an enriched learning experience, student engagement, and a greater connection between ethics and real life

On the role of boron on improving ductility in a new polycrystalline superalloy

AbstractThe role of boron in promoting ductility at high temperature in a prototype nickel-based superalloy designed for industrial gas turbines is studied. Both a boron-containing and boron-free variant are tested in tension at 750 °C, with further in-situ tests carried out using scanning electron microscopy (SEM), to clarify the mechanism of ductility improvement. The improvement in ductility is observed to be greater at the lowest investigated strain rate, where the grain boundary character plays a significant role on the mechanical properties; no ductility improvement was observed at the highest investigated strain rate. The in-situ tests were also performed at 750 °C and revealed directly the greater susceptibility of the grain boundary morphology in the boron-free case to fracture and – in the boron-containing case – the mechanism of ductility enhancement. The findings are supported further by high-resolution electron backscattered diffraction (HR-EBSD) strain mapping which confirms that the distribution of elastic strain and geometrically necessary dislocation (GND) content are influenced markedly by boron addition. The mechanism through which boron indirectly enhances the mechanical properties at elevated temperatures is discussed

About Starobinsky inflation

It is believed that soon after the Planck era, space time should have a semi-classical nature. According to this, the escape from General Relativity theory is unavoidable. Two geometric counter-terms are needed to regularize the divergences which come from the expected value. These counter-terms are responsible for a higher derivative metric gravitation. Starobinsky idea was that these higher derivatives could mimic a cosmological constant. In this work it is considered numerical solutions for general Bianchi I anisotropic space-times in this higher derivative theory. The approach is ``experimental'' in the sense that there is no attempt to an analytical investigation of the results. It is shown that for zero cosmological constant $\Lambda=0$, there are sets of initial conditions which form basins of attraction that asymptote Minkowski space. The complement of this set of initial conditions form basins which are attracted to some singular solutions. It is also shown, for a cosmological constant $\Lambda> 0$ that there are basins of attraction to a specific de Sitter solution. This result is consistent with Starobinsky's initial idea. The complement of this set also forms basins that are attracted to some type of singular solution. Because the singularity is characterized by curvature scalars, it must be stressed that the basin structure obtained is a topological invariant, i.e., coordinate independent.Comment: Version accepted for publication in PRD. More references added, a few modifications and minor correction