Hafnium isotopic insights into the evolution of mantle source contributions to primitive lavas erupted in Turkana, East African Rift System

Compositions of mafic lavas from the Turkana region, within the East African Rift System (EARS), provide valuable contributions to the understanding of the significant processes in continental magmatism. Specifically, new Hf isotopic ratios coupled with new and existing Pb, Sr, Nd, and He isotopic compositions of Quaternary and Tertiary lavas from Turkana reveal compositional contributions from melt generation processes occurring in the sublithospheric mantle versus contributions from melt generation processes in the lithosphere. Pb and Nd compositions demonstrate two separate mixing trends within the Turkana lavas, and together with Sr isotopic compositions, three compositional end-members are revealed: C-Component, EM1, and HIMU. New Hf isotope ratios of the Quaternary and Tertiary Turkana samples presented a temporal correlation, in Hf-Pb space one trend progresses from an EM1-like component to a C-component over time, while the other trend progresses from a HIMU like component to an EM1 like component throughout time. Based on compositional and spatiotemporal relationships, a model is proposed where HIMU is a lithospheric component, EM1 is a sublithospheric component that acts as an agent of metasomatism in the lithosphere, and the C-component is a second sublithospheric end-member likely present as a result of regional plume activity

Facilitating Change in Health Organizations

Purpose: Significant time and effort are needed to facilitate organizational change; thus a well-constructed conceptual model may help health professionals identify and overcome the barriers impeding this process.Design / methodology / approach:Currently, there is no single framework for organizational change that has gained widespread acceptance. However, two well-validated organizational models are the Prochaska and DiClemente transtheoretical model and Green et al. al.’s health promotion model. In this paper we synthesize these models in the context of organizational change for a physician audience. Findings: We created a new model of organizational change that keeps the best elements of both the Prochaska and DiClemente transtheoretical model and Green et al. al.’s health promotion model. Furthermore, an example is illustrated using this approach.Originality / value: Most health organizations lack a consistent approach to managing change. As a result they have not been as effective in this area as they could be. Most previous organization change theorists have attempted to solve this dilemma by constructing new models of organizational change, which they hope will eventually become the dominant model. Our approach is original in that we have incorporated the best features of two pre-existing models. The value of this approach is that improving these existing models has a much greater potential for widespread acceptance than developing yet another new model

Organising people, contructing meanings : social and institutional dynamics in the production of art museum knowledges

PhD ThesisWhile some research has focused on what happens ‘behind the scenes’ in art museums and how this relates to ‘front stage’ museum representations, little has been written about how this relates to what happens ‘centre stage’: in other words, how the organisational structure and culture of an institution influence the art historical knowledges constructed and presented through display. While much work has been done on the relationship between collecting, collections and display, little has been done to examine interpretation practices in museums of art. This thesis attempts to address this gap in order to better understand the importance of the role of interpretation in the construction of art and art history. This thesis presents the results of research into the production of knowledge, understood as modes of representation, at three museums of art: the Rijksmuseum in Amsterdam, Tate Britain in London, and the Peabody Essex Museum in Salem, Massachusetts. The research focuses on the relationship between changing organisational structures and interpretive practices in these institutions, with a focus on how the traditional divide between ‘educators’ and ‘curators’ is being blurred - suggesting a reinvention of the purpose and function of museums of art. Each case study institution had recently undergone (or was in the process of undergoing) significant organisational change, providing a chance to map out or reflect upon changes to interpretation over time. Combining qualitative, ethnographic methods and display analysis, the research attempts to trace the internal, social workings of each institution with the statements of position communicated to visitors. Proceeding from a social constructionist viewpoint that museum displays are a type of embodied theory, and that museums are not merely ‘reflective’ (Macdonald 1996), the research argues that the structural and cultural dynamics of organisations influence the knowledges communicated to visitors. The research argues that staffing structures (and the power and politics that exist within these structures) not only influence the content of exhibitions and displays, but are capable of altering museum representations. In revealing these connections and examining production practices, this research opens up new thinking about the significance of organisational structures in the production of museum knowledges. This thinking challenges naturalised assumptions about the nature of art and its histories, presenting new possibilities for representation, understanding and the experience of visiting exhibitions.Arts and Humanities Research Counci

Evaluation of Corrosion Protection Methods for Reinforced Concrete Highway Structures

Since the 1970s, research projects and field studies have been conducted on different methods for protecting reinforced concrete bridges from corrosion damage. The methods include alternative reinforcement and slab design, barrier methods, electrochemical methods, and corrosion inhibitors. Each method and its underlying principles are described, performance results of laboratory and/or field trials are reviewed, and systems are evaluated based on the results of the trials. Using performance results from the studies and costs obtained from transportation agencies, an economic analysis is used to estimate the cost of each system over a 75 year economic life using discount rates of 2, 4, and 6%. Epoxy-coated reinforcing steel is the most common corrosion protection method used in the United States today. Although controversial in many areas, epoxy-coated reinforcement has performed well in many states, including Kansas, since it was introduced in the early 1970s and is a low-cost backup to many other corrosion protection options. Research on stainless steel reinforcement indicates that it may remain free of corrosion in chloride contaminated concrete for more than 75 years. At a low discount rate (2%), solid stainless steel reinforcement is a cost-effective option compared to other options, but at higher discount rates (4%+), the present value cost of a deck with solid stainless steel is significantly higher than that of an unprotected deck. Stainless steel clad reinforcement is much less expensive than solid stainless steel reinforcement. The performance of stainless steel-clad reinforcement will be similar to that of solid stainless steel bars if the stainless steel coating is continuous and if the black steel core, exposed at the bar ends, is protected so that it does not come into contact with concrete pore solution. The present value of the cost of a bridge deck built with stainless steel-clad reinforcement is significantly lower than the present value for the cost of any other corrosion protection system. This method should be considered for experimental use. Solid stainless steel should be considered, as well, if a low discount rate (around 2%) is used. Hot rubberized asphalt membranes are the least expensive option, other than stainless steel-clad reinforcement. Hot rubberized asphalt and spray-applied liquid membranes should be considered for use on future projects. In laboratory tests, corrosion inhibitors have been shown to provide protection to steel in chloride contaminated concrete, but information on their performance in the field is limited. Both calcium nitrite and organic corrosion inhibitors have the potential to be cost-effective, if they perform as well in the field as they have in the laboratory, and should be considered for experimental use

The Safe Zone--It\u27s not segregation

Let\u27s talk about the Safe Zone. Let\u27s talk about the creation of a ten room, single occupancy wing which is open to heterosexuals, allies, gays, lesbians, bisexual, transgendered, as well as thos who haven\u27t quite self-identified as… Let\u27s be realistic, the Safe Zone, as proposed, will not come close to housing every gay and lesbian on the University of Maine campus, nor is that its attempt

Optimization of rice bread formulation by mixture design and relationship of bread quality to flour and dough attributes

The bread making aptitude of five rice flours (native and gelatinized) and five gluten substitutes (GS) were prior tested and the best ingredients for mixture design were set. Native flour with a wide distribution of particle size, xanthan gum (XG), guar gum (GG) and sodium alginate (SA) were selected due to their good performance. The effect of formulation on bread volume (BV), cell area fraction (CAF) of breadcrumb and dough rheology was determined by using a simplex centroid mixture design with constrain (2.1 g of GS/100 g of flour). A significant effect of formulation on viscoelasticity of dough was observed. A non-linear relationship between BV and dough viscosity was found with maximum BV at 60000 Pa⋅s. The optimum formulation, from XG to GG mass ratio of 0.71, yields maximum values of BV (4.07 ml/g of flour) and CAF (29%); optimum bread presented good textural attributes and a slightly toasted crust.Fil: Cajas Locke, Jennifer Elizabeth. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: González, Luciana Carla. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Loubes, María Ana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Tolaba, Marcela Patricia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentin

About Landcape Show Card

Show card for About Landscape. September 6 - October 2, 2002.https://digitalcommons.udallas.edu/about_landcape/1000/thumbnail.jp

Differences in Nursery Pigs’ Behavior on the Day of Vaccination

Swine industry feed suppliers are continually striving to develop techniques and tools to reduce the additive stressors imposed on the weanling piglet, to increase advantageous behaviors (feeding and drinking) and to reduce aggressive interactions. One product on the market designed to ease the transition from a liquid diet (sow\u27s milk) to a dry ration is a gel-based feed supplement that was incorporated in this trial as a means to positively affect feeding and drinking behaviors. The objectives of this study were to determine if there were differences in the nursery pigs’ behavior on the day of vaccination when provided a gel supplement. A total of 29 d crossbred pigs (5.94 kg) were housed in Double L® confinement nursery buildings. Four treatments were compared. No vaccine and no gel (control n = 4) defined as unvaccinated and without supplemental gel at days 8 to 10. No vaccine and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 without vaccination. Vaccinated and no gel (n = 4) defined as pigs that were vaccinated but did not receive supplemental gel at days 8 to 10. Vaccinated and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 and were vaccinated. The group of four pigs housed together in a pen was considered the experimental unit for data analysis. Definitions for the behaviors and postures recorded and summarized for the trial included the following: Active was defined as standing, this included any upright postures. Inactive posture was defined as sitting or lying postures (both lateral and sternal). Time at drinker was defined as when an individual pig’s mouth was around the water nipple. Time at feeding stations was defined as the time when the individual pig’s head was inside the creep (that contained gel) or the three hole feeder (dry pelleted feed). Nursery aged pigs were less active (P \u3c 0.05; Figure 1) and spent less time (P \u3c 0.05; Figure 2) at the feeding stations 1- h after receiving Mycoplasma hyopneumoniae vaccination, indicating a short term behavioral response to this stressor. These behavioral alterations continued for approximately 6- h (or 5:00 PM the vaccination day afternoon). After this time, all nursery pigs regardless of treatment engaged in the same behavioral repertoire. However, the behavioral repertoire of these nursery pigs were not different over the 3-d trial (previously published worked by Johnson et al., 2008) suggesting that the effects of this vaccination stressor and product were not long lasting