The asymptotic equivalence of fixed heat flux and fixed temperature thermal boundary conditions for rapidly rotating convection

The influence of fixed temperature and fixed heat flux thermal boundary conditions on rapidly rotating convection in the plane layer geometry is investigated for the case of stress-free mechanical boundary conditions. It is shown that whereas the leading order system satisfies fixed temperature boundary conditions implicitly, a double boundary layer structure is necessary to satisfy the fixed heat flux thermal boundary conditions. The boundary layers consist of a classical Ekman layer adjacent to the solid boundaries that adjust viscous stresses to zero, and a layer in thermal wind balance just outside the Ekman layers adjusts the temperature such that the fixed heat flux thermal boundary conditions are satisfied. The influence of these boundary layers on the interior geostrophically balanced convection is shown to be asymptotically weak, however. Upon defining a simple rescaling of the thermal variables, the leading order reduced system of governing equations are therefore equivalent for both boundary conditions. These results imply that any horizontal thermal variation along the boundaries that varies on the scale of the convection has no leading order influence on the interior convection

One place doesn't fit all: improving the effectiveness of sustainability standards by accounting for place

Includes bibliographical references (pages 8-10).The growing interest in incentivizing sustainable agricultural practices is supported by a large network of voluntary production standards, which aim to offer farmers and ranchers increased value for their product in support of reduced environmental impact. To be effective with producers and consumers alike, these standards must be both credible and broadly recognizable, and thus are typically highly generalizable. However, the environmental impact of agriculture is strongly place-based and varies considerably due to complex biophysical, socio-cultural, and management-based factors, even within a given sector in a particular region. We suggest that this contradiction between the placeless generality of standards and the placed-ness of agriculture renders many sustainability standards ineffective. In this policy and practice review, we examine this contradiction through the lens of beef production, with a focus on an ongoing regional food purchasing effort in Denver, Colorado, USA. We review the idea of place in the context of agricultural sustainability, drawing on life cycle analysis and diverse literature to find that recognition of place-specific circumstances is essential to understanding environmental impact and improving outcomes. We then examine the case of the Good Food Purchasing Program (GFPP), a broad set of food-purchasing standards currently being implemented for institutional purchasing in Denver. The GFPP was created through a lengthy stakeholder-inclusive process for use in Los Angeles, California, USA, and has since been applied to many cities across the country. The difference between Los Angeles' process and that of applying the result of Los Angeles' process to Denver is instructive, and emblematic of the flaws of generalizable sustainability standards themselves. We then describe the essential elements of a place-based approach to agricultural sustainability standards, pointing toward a democratic, process-based, and outcome-oriented strategy that results in standards that enable rather than hinder the creativity of both producers and consumers. Though prescription is anathema to our approach, we close by offering a starting point for the development of standards for beef production in Colorado that respect the work of people in place

Patterning servo-mechanism for a circular warp knitting machine

Warp knitting is always performed on flat (linear) knitting machines. A circular warp-knitting machine is recently made possible by using a novel concept of a conical needle bed and patterning cams with enclosed cam followers to drive the patterning rings. This also requires a mechanical linkage to transmit the motion from the patterning cam to the patterning rings, which is prone to vibration at undesirable levels. A new generation design replaces the mechanical cam and linkage with high-speed AC brushless servomotors enabling limitless precision patterning possibilities. A method of selecting servomotors based on minimising the power required to perform the fastest motion required for a given application is reported. This method ensures cost minimising by selecting the smallest servomotor suitable for a given application. A circular warp-knitting machine using servomotor to drives selected using the method reported is designed, built and successfully tested

Explorations, Vol. 3, No. 1

Cover: Debouche, a thermo-formed acrylic sculpture, by Deborah de Moulpied, Associate Professor of Art at the University of Maine, (from the collection of Barbara Heldt and Gerald Smith, Oxford, England); photograph by Dale and Nedra Van Volkinburg. Articles include: Biotechnology, by Michael R. Gross The Search for Tom Swift or Some Reflections on One of America\u27s Best-Known Cultural Heroes, by David K. Vaughan ENDO-EXO 1 Sculpture in Motion Communication is Not Just Saying Words; It is Creating True Understanding, by Marisue Pickering Maine Outreach: Teaching Success, by Richard A. Hale and James F. Philp Through Cloud and Fog, Hunting the Elusive pH, by Richard Jagels Ocean Basin with a Past A Cryptic History: Breaking the Code Discerning a Future, by Detmar Schnitker We Stand Corrected in Volume II, Number 2, of EXPLORATIONS Dialogue: Letters [to the Editor] Updates from the Dispatch Cas

An analog of glibenclamide selectively enhances autophagic degradation of misfolded α1-antitrypsin Z

The classical form of α1-antitrypsin deficiency (ATD) is characterized by intracellular accumulation of the misfolded variant α1-antitrypsin Z (ATZ) and severe liver disease in some of the affected individuals. In this study, we investigated the possibility of discovering novel therapeutic agents that would reduce ATZ accumulation by interrogating a C. elegans model of ATD with high-content genome-wide RNAi screening and computational systems pharmacology strategies. The RNAi screening was utilized to identify genes that modify the intracellular accumulation of ATZ and a novel computational pipeline was developed to make high confidence predictions on repurposable drugs. This approach identified glibenclamide (GLB), a sulfonylurea drug that has been used broadly in clinical medicine as an oral hypoglycemic agent. Here we show that GLB promotes autophagic degradation of misfolded ATZ in mammalian cell line models of ATD. Furthermore, an analog of GLB reduces hepatic ATZ accumulation and hepatic fibrosis in a mouse model in vivo without affecting blood glucose or insulin levels. These results provide support for a drug discovery strategy using simple organisms as human disease models combined with genetic and computational screening methods. They also show that GLB and/or at least one of its analogs can be immediately tested to arrest the progression of human ATD liver disease.</div

Outcomes from an Interprofessional Educational Model for Teaching Community Health

Interprofessional team work is widely recognized as an essential component of our health care delivery system. At UMass, an interprofessional educational partnership was established with the goal of promoting interprofessional teaching to medical and nursing students in the area of community health. Presented at the UMMS Commonwealth Medicine Academic Conference, Worcester, Mass. in 2006

On the alleged simplicity of impure proof

Roughly, a proof of a theorem, is “pure” if it draws only on what is “close” or “intrinsic” to that theorem. Mathematicians employ a variety of terms to identify pure proofs, saying that a pure proof is one that avoids what is “extrinsic,” “extraneous,” “distant,” “remote,” “alien,” or “foreign” to the problem or theorem under investigation. In the background of these attributions is the view that there is a distance measure (or a variety of such measures) between mathematical statements and proofs. Mathematicians have paid little attention to specifying such distance measures precisely because in practice certain methods of proof have seemed self- evidently impure by design: think for instance of analytic geometry and analytic number theory. By contrast, mathematicians have paid considerable attention to whether such impurities are a good thing or to be avoided, and some have claimed that they are valuable because generally impure proofs are simpler than pure proofs. This article is an investigation of this claim, formulated more precisely by proof- theoretic means. After assembling evidence from proof theory that may be thought to support this claim, we will argue that on the contrary this evidence does not support the claim