Airloads on bluff bodies, with application to the rotor-induced downloads on tilt-rotor aircraft

The aerodynamic characteristics of airfoils with several flap configurations were studied theoretically and experimentally in environments that simulate a wing immersed in the downwash of a hovering rotor. Special techniques were developed for correcting and validating the wind tunnel data for large blockage effects, and the test results were used to evaluate two modern blockage effects, and the test results were used to evaluate two modern computational aerodynamics codes. The combined computed and measured results show that improved flap and leading-edge configurations can be designed which will achieve large reductions in the downloads of tilt-rotor aircraft, and thereby improve their hover efficiency

Computational Modeling of Gas-Surface Interactions for High-Enthalpy Reacting Flows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106443/1/AIAA2013-187.pd

Multi-scale environmental filters and niche partitioning govern the distributions of riparian vegetation guilds

Across landscapes, riparian plant communities assemble under varying levels of disturbance, environmental stress, and resource availability, leading to the development of distinct riparian life-history guilds over evolutionary timescales. Identifying the environmental filters that exert selective pressures on specific riparian vegetation guilds is a critical step in setting baseline expectations for how riparian vegetation may respond to environmental conditions anticipated under future global change scenarios. In this study, we ask: (1) What riparian plant guilds exist across the interior Columbia and upper Missouri River basins? (2) What environmental filters shape riparian guild distributions? (3) How does resource partitioning among guilds influence guild distributions and co-occurrence? Woody species composition was measured at 703 stream reaches and each species\u27 morphological and functional attributes were extracted from a database in four categories: (1) life form, (2) persistence and growth, (3) reproduction, and (4) resource use. We clustered species into guilds by morphological characteristics and attributes related to environmental tolerances, modeling these guilds\u27 distributions as a function of environmental filters-regional climate, watershed hydrogeomorphic characteristics, and stream channel form- and guild coexistence. We identified five guilds: (1) a tall, deeply rooted, long-lived, evergreen tree guild, (2) a xeric, disturbance tolerant shrub guild, (3) a hydrophytic, thicket-forming shrub guild, (4) a low-statured, shadetolerant, understory shrub guild, and (5) a flood tolerant, mesoriparian shrub guild. Guilds were most strongly discriminated by species\u27 rooting depth, canopy height and potential to resprout and grow following biomass-removing disturbance (e.g., flooding, fire). Hydro-climatic variables, including precipitation, watershed area, water table depth, and channel form attributes reflective of hydrologic regime, were predictors of guilds whose life history strategies had affinity or aversion to flooding, drought, and fluvial disturbance. Biotic interactions excluded guilds with divergent life history strategies and/or allowed for the co-occurrence of guilds that partition resources differently in the same environment. We conclude that the riparian guild framework provides insight into how disturbance and bioclimatic gradients shape riparian functional plant diversity across heterogeneous landscapes. Multiple environmental filters should be considered when the riparian response guild framework is to be used as a decisionsupport tool framework across large spatial extents. Copyright: © 2015 Hough-Snee et al

The nature, extent and impact of educator targeted bullying on school teachers in West Malaysia

This study examines the nature, prevalence and impact of educator targeted bullying (ETB) in a sample of 575 Malaysian school teachers. Specifically it was predicted that ethnicity may be related to exposure to ETB; that frequency of exposure would vary by type of ETB; that there would be tenure-related differences in terms of exposure and burnout; and that teaching experience could moderate the exposure burnout relationship. Results suggest that less severe forms of ETB are more prevalent than physical forms; and that educators with increased teaching experience are less exposed to ETB. ETB exhibits a negative impact on burnout; and is strongest for student-related burnout. Increased experience buffers the ETB-student-related burnout relationship while ethnicity is unrelated to exposure to ETB

Pulsed Feedback Defers Cellular Differentiation

Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable “polyphasic” positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a “timer” that operates over timescales much longer than a cell cycle

Reexamining evidence-based practice in community corrections: beyond 'a confined view' of what works

This article aims to reexamine the development and scope of evidence-based practice (EBP) in community corrections by exploring three sets of issues. Firstly, we examine the relationships between the contested purposes of community supervision and their relationships to questions of evidence. Secondly, we explore the range of forms of evidence that might inform the pursuit of one purpose of supervision—the rehabilitation of offenders—making the case for a fuller engagement with “desistance” research in supporting this process. Thirdly, we examine who can and should be involved in conversations about EBP, arguing that both ex/offenders’ and practitioners’ voices need to be respected and heard in this debate

The pains of desistance

Desistance is generally presented in a positive light, with themes of ‘making good’ and generativity recurring in the literature. This article reports on two qualitative studies exploring the desistance journeys of two different groups of ex-offenders, drawing attention to the pains of this process. It examines the possible consequences of these ‘pains of desistance’ and how they are linked to three spheres of desistance: act-desistance; identity desistance; and relational desistance. The attempt to achieve act-desistance often led to the pain of isolation for our interviewees, while the clash between the need to achieve identity desistance and a lack of relational desistance (especially on the meso- and macro-levels) meant that they suffered the pain of goal failure. The pains of isolation and goal failure combined to lead to the further pain of hopelessness. Those interviewed were indeed ‘going straight’, but taking this path led many to a limited and often diminished life