Investigation of the functional expression of purine and pyrimidine receptors in porcine isolated pancreatic arteries

Receptors for purines and pyrimidines are expressed throughout the cardiovascular system. This study investigated their functional expression in porcine isolated pancreatic arteries. Pancreatic arteries (endothelium intact or denuded) were prepared for isometric tension recording and preconstricted with U46619, a thromboxane A2 mimetic; adenosine-5′-diphosphate (ADP), uridine-5′-triphosphate (UTP) and MRS2768, a selective P2Y2 agonist, were applied cumulatively, while adenosine-5′-triphosphate (ATP) and αβ-methylene-ATP (αβ-meATP) response curves were generated from single concentrations per tissue segment. Antagonists/enzyme inhibitors were applied prior to U46619 addition. ATP, αβ-meATP, UTP and MRS2768 induced vasoconstriction, with a potency order of αβ-meATP > MRS2768 > ATP ≥ UTP. Contractions to ATP and αβ-meATP were blocked by NF449, a selective P2X1 receptor antagonist. The contraction induced by ATP, but not UTP, was followed by vasorelaxation. Endothelium removal and DUP 697, a cyclooxygenase-2 inhibitor, had no significant effect on contraction to ATP but attenuated that to UTP, indicating actions at distinct receptors. MRS2578, a selective P2Y6 receptor antagonist, had no effect on contractions to UTP. ADP induced endothelium-dependent vasorelaxation which was inhibited by MRS2179, a selective P2Y1 receptor antagonist, or SCH58261, a selective adenosine A2A receptor antagonist. The contractions to ATP and αβ-meATP were attributed to actions at P2X1 receptors on the vascular smooth muscle, whereas it was shown for the first time that UTP induced an endothelium-dependent vasoconstriction which may involve P2Y2 and/or P2Y4 receptors. The relaxation induced by ADP is mediated by P2Y1 and A2A adenosine receptors. Porcine pancreatic arteries appear to lack vasorelaxant P2Y2 and P2Y4 receptors

The effects of market competition and international orientation on Management Control Systems' use by Emerging Market Publicly Listed Companies

Concurrent Sessions - 1. Management Control System Design: Accounting – Advanced – 1.5CHWe examine the effects of market competition and international orientation on management control systems’ use by emerging market Public Listed Companies (PLCs). Our inquiry focuses specifically on China because this country is the world’s largest annual source of exports from among emerging market countries. We examine management control systems whose widespread use by Chinese PLCs has been documented by prior accounting research: formal procedures, strategic planning, approval procedures, budget targets, participative budgeting and performance evaluation. We provide empirical evidence that the association between two specific types of market competition (foreign entrants’ competition and customers’ buying power) and management control systems’ use depends on whether the PLCs compete predominantly in the domestic or international market. We discuss implications of our findings and provide some directions for future research.published_or_final_versionThe 2010 Management Accounting Section Research and Case Conference and IMA/MAS Doctoral Colloquium, Seattle, WA., 6-9 January 2010

Overcoming data sparsity

Unilever is currently designing and testing recommendation algorithms that would make recommendations about products to online customers given the customer ID and the current content of their basket. Unilever collected a large amount of purchasing data that demonstrates that most of the items (around 80%) are purchased infrequently and account for 20% of the data while frequently purchased items account for 80% of the data. Therefore, the data is sparse, skewed and demonstrates a long tail. Attempts to incorporate the data from the long tail, so far have proved difficult and current Unilever recommendation systems do not incorporate the information about infrequently purchased items. At the same time, these items are more indicative of customers' preferences and Unilever would like to make recommendations from/about these items, i.e. give a rank ordering of available products in real time. Study Group suggested to use the approach of bipartite networks to construct a similarity matrix that would allow the recommendation scores for different products to be computed. Given a current basket and a customer ID, this approach gives recommendation scores for each available item and recommends the item with the highest score that is not already in the basket. The similarity matrix can be computed offline, while recommendation score calculations can be performed live. This report contains the summary of Study Group findings together with the insights into properties of the similarity matrix and other related issues, such as recommendation for the data collection

Software de laboratorio para el diseño, implementación y operación de controladores PIDs

En el laboratorio de Ingeniería de Sistemas y Automática de la sede Mergelina de la EII se dispone de varias plantas piloto con distintos objetivos de control, todas ellas instrumentadas y conectadas a ordenadores personales para su supervisión y control. Para el desarrollo de este proyecto se ha dispuesto de una planta de control de nivel de agua de un depósito y la plataforma de desarrollo de software LabView de National Instruments. El objetivo del proyecto se basa en el desarrollo de un software que permita el diseño, implementación y operación de PIDs contemplando todas las etapas de diseño y estableciendo la comunicación con la planta a través del estándar OPC. Con todo ello el alumno podrá realizar prácticas para el desarrollo de sus conocimientos en automática referente a estudios en lazo abierto, lazo cerrado y cálculos de los parámetros de un PID de manera experimental.Departamento de Ingeniería de Sistemas y AutomáticaGrado en Ingeniería en Electrónica Industrial y Automátic

Protein Kinase B Regulates T Lymphocyte Survival, Nuclear Factor κb Activation, and Bcl-XL Levels in Vivo

The serine/threonine kinase protein kinase B (PKB)/Akt mediates cell survival in a variety of systems. We have generated transgenic mice expressing a constitutively active form of PKB (gag-PKB) to examine the effects of PKB activity on T lymphocyte survival. Thymocytes and mature T cells overexpressing gag-PKB displayed increased active PKB, enhanced viability in culture, and resistance to a variety of apoptotic stimuli. PKB activity prolonged the survival of CD4+CD8+ double positive (DP) thymocytes in fetal thymic organ culture, but was unable to prevent antigen-induced clonal deletion of thymocytes expressing the major histocompatibility complex class I–restricted P14 T cell receptor (TCR). In mature T lymphocytes, PKB can be activated in response to TCR stimulation, and peptide-antigen–specific proliferation is enhanced in T cells expressing the gag-PKB transgene. Both thymocytes and T cells overexpressing gag-PKB displayed elevated levels of the antiapoptotic molecule Bcl-XL. In addition, the activation of peripheral T cells led to enhanced nuclear factor (NF)-κB activation via accelerated degradation of the NF-κB inhibitory protein IκBα. Our data highlight a physiological role for PKB in promoting survival of DP thymocytes and mature T cells, and provide evidence for the direct association of three major survival molecules (PKB, Bcl-XL, and NF-κB) in vivo in T lymphocytes

Chapter 2 Established and Emerging Techniques for Characterising the Formation, Structure and Performance of Calcified Structures under Ocean Acidification

Ocean acidification (OA) is the decline in seawater pH and saturation levels of calcium carbonate (CaCO3) minerals that has led to concerns for calcifying organisms such as corals, oysters and mussels because of the adverse effects of OA on their biomineralisation, shells and skeletons. A range of cellular biology, geochemistry and materials science approaches have been used to explore biomineralisation. These techniques have revealed that responses to seawater acidification can be highly variable among species, yet the underlying mechanisms remain largely unresolved. To assess the impacts of global OA, researchers will need to apply a range of tools developed across disciplines, many of which are emerging and have not yet been used in this context. This review outlines techniques that could be applied to study OA-induced alterations in the mechanisms of biomineralisation and their ultimate effects on shells and skeletons. We illustrate how to characterise, quantify and monitor the process of biomineralisation in the context of global climate change and OA. We highlight the basic principles, as well as the advantages and disadvantages, of established, emerging and future techniques for OA researchers. A combination of these techniques will enable a holistic approach and better understanding of the potential impact of OA on biomineralisation and its consequences for marine calcifiers and associated ecosystems

Persistent Transport Barrier on the West Florida Shelf

Analysis of drifter trajectories in the Gulf of Mexico has revealed the existence of a region on the southern portion of the West Florida Shelf (WFS) that is not visited by drifters that are released outside of the region. This so-called ``forbidden zone'' (FZ) suggests the existence of a persistent cross-shelf transport barrier on the southern portion of the WFS. In this letter a year-long record of surface currents produced by a Hybrid-Coordinate Ocean Model simulation of the WFS is used to identify Lagrangian coherent structures (LCSs), which reveal the presence of a robust and persistent cross-shelf transport barrier in approximately the same location as the boundary of the FZ. The location of the cross-shelf transport barrier undergoes a seasonal oscillation, being closer to the coast in the summer than in the winter. A month-long record of surface currents inferred from high-frequency (HF) radar measurements in a roughly 60 km $\times$ 80 km region on the WFS off Tampa Bay is also used to identify LCSs, which reveal the presence of robust transient transport barriers. While the HF-radar-derived transport barriers cannot be unambiguously linked to the boundary of the FZ, this analysis does demonstrate the feasibility of monitoring transport barriers on the WFS using a HF-radar-based measurement system. The implications of a persistent cross-shelf transport barrier on the WFS for the development of harmful algal blooms on the shoreward side of the barrier are considered.Comment: Submitted to Geophysical Research Letter

Chitin Facilitated Mineralization in the Eastern Oyster

Chitin is often reported in molluscan shells, where it likely contributes to the mechanical strength of the biomineral. However, the role of this polysaccharide in relation to the process of shell formation is not well understood. We investigated the deposition of chitin during shell repair in the Eastern oyster, Crassostrea virginica, by inserting stainless steel and glass implants in a region of shell damage. This work documents the time course of deposition of both chitin fibrils and calcium carbonate layers. Chitin was detected by confocal laser scanning microscopy (CLSM) using a chitin-specific fluorescent probe that was produced from clones of a chitin-binding domain. The presence of fibrils was confirmed using electron microscopy of implants. The fibrils’ dimensions were reduced after treatment with both acid and bleach, suggesting that chitin interacts with inorganic minerals and other organic components such as proteins and lipids as early as 5 h after shell damage. With CLSM, it was shown that chitin co-localized with the cell membrane, suggesting the importance of cells located on the implants in the process of fibril formation. Using observations from this study as well as those from the literature on chitin synthase production, we propose two cellular models for chitin deposition related to shell formation