Stochastic estimation as a statistical tool for approximating turbulent conditional averages

In this paper, extensions to conventional stochastic estimation techniques are presented, whereby uncertainties in individual estimates may be deduced. Test applications to time series of velocity measurements in a turbulent boundary layer confirm the fidelity of the uncertainty estimation procedure and illustrate how the optimal choice of stochastic estimation model can be strongly dependent on the event upon which the average is conditioned. They also demonstrate how stochastic estimations may be refined to yield more accurate descriptions of particular coherent motions, and how they can reveal the existence of rare events, different in statistical character to their more frequent counterparts, which might otherwise be undetected by conventional stochastic estimation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70314/2/PFADEB-4-9-2046-1.pd

An adaptive turbulence filter for decomposition of organized turbulent flows

A new decomposition has been developed in which turbulent processes in shear flows may be represented as a combination of organized and more random turbulent motions. Each component is modeled as a summation of its characteristic eddies, of strength that varies in time and space as a function of the entire process. The contribution of all turbulent eddies of the more random component are estimated with an adaptive turbulence filter, which recognizes this component as the orthogonal partner to organized motion, with a power density spectrum of appropriate shape. The decomposition recovers organized motion from time and space series of data in a physically meaningful way, and can be used to characterize interaction between coherent and more random motions. It also provides an estimate for the turbulence in shear flows that are too complex for a meaningful average motion to be identified.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69639/2/PHFLE6-6-5-1775-1.pd

John W. O\u27Malley: Scholar of Eloquence and Eloquent Scholar

ABSTRACT As the essays in this volume attest, John O’Malley, S.J., has been an intellectual force in the proud tradition of the erudite, generative, multi-lingual polymaths of the early Society. Reading the recent memoir on his rich scholarly life over several decades, The Education of a Historian (2021)i, viewing the wonderful Georgetown Interview (2021), and having had the chance to interview him in Baltimore on May 26, 2022,ii we are struck by his relentless curiosities across multiple fields of historical inquiry and his willingness to follow his questions over decades as they take on new forms and incarnations, both alone -- and with many others. We witness his meticulous and deep commitment to understanding original sources of the Renaissance on their own terms, his work to modernize the historiography of confessional and religious history, and his capacious analytic and synthetic prowess in bringing historical moments, movements, institutions, and figures “to life” to make more present pasts, and to participate in the present itself. In this epideictic piece (one of O’Malley’s favorite genres for analysis), we want to share some of the ways in which he backed into, participated in, and ultimately sponsored the emerging field of Jesuit rhetoric, nationally and internationally, over the last several decades, albeit somewhat unwittingly. While we appreciate O’Malley’s primary identity as a new historian of religious history, and his reluctance to call himself a rhetorician, we think it is important to acknowledge his serendipitous and fertile encounters with rhetorical studies. We briefly trace his changing relationship to rhetorical study, from his first efforts to use it as a frame for textual analysis, to seeing it as an enduring centering principle for Jesuit society and ministries writ large, and finally as a set of valuable principles that can be renewed for Jesuit education today. And we share the perspectives from a sampling of those who have been influenced by his work across these areas internationally and within an American higher education context

Dynamic response of boundary‐layer turbulence to oscillatory shear

The temporal response of a well‐developed turbulent boundary layer to the superposition of oscillatory shear has been measured experimentally, over a wide range of frequencies. The response is primarily a periodic organization in magnitude of components of the turbulent velocity field at the forcing frequency. Oscillatory production of turbulence arises predominantly as a modulation of the mean production process in the parent boundary layer. Close to the wall, the relative phases of response of components of turbulent kinetic energy indicate that temporal redistribution of turbulent kinetic energy is driven by robust coherent motions of the underlying mean flow. The local directions of redistribution deduced from these measurements indicate a wall impingement (splatting) effect, consistent with characterizations from numerical simulation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70705/2/PFADEB-3-1-178-1.pd

Encouraging and Supporting Teacher Research in the US and UK

Given the diversity of types of writing instructors in US and UK tertiary education and the range of their scholarly backgrounds, the likelihood is that most instructors have not participated in research in composition theory or pedagogy, rhetoric, academic literacies, or writing studies. The four projects reported here highlight the research opportunities and capacities of this diverse group, reflecting different types and levels of teacher or practitioner inquiry that involves teachers in studying significant questions arising from their own contexts. The article offers a brief history of practitioner inquiry research in its various forms and traditions; presents the projects themselves, including their aims and framing; and offers specific recommendations for the future of this invaluable form of inquiry. Definitions of action research vary greatly. The term in its broadest sense refers to research conducted in a field setting with those actually involved in that field, often along with an ‘outsider’, into the study of questions influenced by practitioners, rather than solely by ‘experts’ (Noffke 1996: 2). At the end of the day as teachers, we are often left wondering: Are we doing enough? How do we know? These are the essential questions that occupy the hearts and minds of so many of us as we walk into our classrooms (Goswami, Lewis and Rutherford 2009: 2).Teacher research just isn’t like other forms of research, in part because there is no blueprint for how to do it (Goswami, Lewis and Rutherford 2009: 1)

Are neonicotinoid insecticides driving declines of widespread butterflies?

There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild and managed bees for some years, but recently attention has shifted to examining broader effects they may be having on biodiversity. For example in the Netherlands, declines in insectivorous birds are positively associated with levels of neonicotinoid pollution in surface water. In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices. By contrast, the number of hectares of farmland where neonicotinoid pesticides are used is negatively associated with butterfly indices. Indices for 15 of the 17 species show negative associations with neonicotinoid usage. The declines in butterflies have largely occurred in England, where neonicotinoid usage is at its highest. In Scotland, where neonicotinoid usage is comparatively low, butterfly numbers are stable. Further research is needed urgently to show whether there is a causal link between neonicotinoid usage and the decline of widespread butterflies or whether it simply represents a proxy for other environmental factors associated with intensive agriculture

Nature tourism and Irish film

This article provides a historical overview and reading of seminal Irish film from the perspective of nature tourism. Within Irish cultural studies, tourism is frequently equated with an overly romantic image of the island, which has been used to sell the country abroad. However, using notions like the tourist gaze and taking on board influential debates around space/place, one can posit a more progressive environmental vision of nature and landscape in our readings of film

Predicting resilience of ecosystem functioning from co‐varying species' responses to environmental change

Understanding how environmental change affects ecosystem function delivery is of primary importance for fundamental and applied ecology. Current approaches focus on single environmental driver effects on communities, mediated by individual response traits. Data limitations present constraints in scaling up this approach to predict the impacts of multivariate environmental change on ecosystem functioning. We present a more holistic approach to determine ecosystem function resilience, using long‐term monitoring data to analyze the aggregate impact of multiple historic environmental drivers on species' population dynamics. By assessing covariation in population dynamics between pairs of species, we identify which species respond most synchronously to environmental change and allocate species into “response guilds.” We then use “production functions” combining trait data to estimate the relative roles of species to ecosystem functions. We quantify the correlation between response guilds and production functions, assessing the resilience of ecosystem functioning to environmental change, with asynchronous dynamics of species in the same functional guild expected to lead to more stable ecosystem functioning. Testing this method using data for butterflies collected over four decades in the United Kingdom, we find three ecosystem functions (resource provisioning, wildflower pollination, and aesthetic cultural value) appear relatively robust, with functionally important species dispersed across response guilds, suggesting more stable ecosystem functioning. Additionally, by relating genetic distances to response guilds we assess the heritability of responses to environmental change. Our results suggest it may be feasible to infer population responses of butterflies to environmental change based on phylogeny—a useful insight for conservation management of rare species with limited population monitoring data. Our approach holds promise for overcoming the impasse in predicting the responses of ecosystem functions to environmental change. Quantifying co‐varying species' responses to multivariate environmental change should enable us to significantly advance our predictions of ecosystem function resilience and enable proactive ecosystem management

The influence of cervical and thoracic lymphadenectomy on corneal allograft rejection in inbred rats

Aim To investigate the site of alloantigen presentation in the rat following orthotopic corneal transplantation. Methods Adult inbred Fischer 344 rats received penetrating corneal allografts from inbred Wistar Furth donors (n¼17), without lymphadenectomy. A second group (n¼8) underwent bilateral removal of superficial cervical and facial lymph nodes 7 days before transplantation. A third group (n¼9) underwent bilateral removal of superficial cervical, facial, internal jugular and posterior cervical nodes. Graft survival was assessed by corneal clarity and rejection was confirmed histologically. Results All allografts underwent rejection. The median time to rejection for unmodified allografts was day 15, compared with day 14.5 for minimally lymphadenectomised recipients and day 18 for more extensively lymphadenectomised recipients (p>0.05, all comparisons). The median day to rejection for the combined group of lymphadenectomised rats was day 17 (p>0.05 compared with unmodified grafts). The rejection process was similar in all recipients. Conclusions Removal of multiple lymph nodes in the neck and thorax did not significantly influence the incidence, tempo or nature of the corneal allograft response. Sensitisation and clonal expansion of corneal alloantigen-reactive cells cannot occur only in superficial cervical, facial, internal jugular and posterior cervical lymph nodes in the rat.We acknowledge financial support from the Australian National Health and Medical Research Council and the Ophthalmic Research Institute of Australia