Effect of hydrostatic pressure on anelastic stress relaxation in a mixed-alkali silicate glass

The effect of hydrostatic pressure on the anelastic stress relaxation of a mixed-alkali silicate glass (0.05 Na₂O, 0.95 K₂O, 3 SiO₂) was studied at 75°C between ambient pressure and 6 kbar. The activation volume of diffusion was found to be - 4.2 cm³/mole. It is proposed that a reequilibration of the defect population at pressure gives rise to the negative activation volume of diffusion --Abstract, page ii

Phospholipase D in brain function and Alzheimer's disease

Alzheimer's disease is the most common neurodegenerative disorder. Although lipids are major constituents of brain, their role in Alzheimer's disease pathogenesis is poorly understood. Much attention has been given to cholesterol, but growing evidence suggests that other lipids, such as phospholipids, might play an important role in this disorder. In this review, we will summarize the evidence linking phospholipase D, a phosphatidic acid-synthesizing enzyme, to multiple aspects of normal brain function and to Alzheimer's disease. The role of phospholipase D in signaling mechanisms downstream of beta-amyloid as well as in the trafficking and processing of amyloid precursor protein will be emphasized.We would like to thank Robin Chan, Samuel Frere, KimberlyRobinson, and Zachary Freyberg for critical reading of the manuscript.Work from T.G.O. is supported by the Portuguese Foundation forScience and Technology SFRH/BD/33237/2007 and the Luso-Amer-ican Development Foundatio

Collaborative Concept Mapping on the World Wide Web

The Collaborative Concept Mapping project is a joint research project between IMD and EPFL. The goal of the project is to create a collaborative tool that helps managers to define business strategies in the face of complex situations. Addressing complex problems requires collaboration on models in order to integrate multiple views and create shared understanding. Because of the rapidly changing nature of the business world, models have a short life expectancy. Managers cannot wait for the creation of the ultimate models before testing them in the real world. In order for models to be created and shared by people, a method and a tool for building them are needed. In this article we propose a method and a tool that integrate systems theory, management learning, and software engineering practices for addressing complex problems

Fretting Corrosion Behavior of Additive Manufactured and Cryogenic-Machined Ti6Al4V for Biomedical Applications

Metal ion release, caused by synergistic effect of wear and corrosion, is one of the major concerns related to the prostheses lifetime. In this work, samples of additive manufactured Ti6Al4V are machined under dry cutting and cryogenic cooling conditions and their performances in terms of corrosion and fretting corrosion response are investigated. A wet and temperature-controlled apparatus equipped with an electro-chemical cell is designed and set-up in order to evaluate the fretting corrosion effect acting at the interfaces. The obtained results show that the cryogenic machining improves the corrosion and fretting corrosion behavior of the investigated additive manufactured Ti6Al4V

Phospholipase D functional ablation has a protective effect in an Alzheimer's disease Caenorhabditis elegans model

Phospholipase D (PLD) is a key player in the modulation of multiple aspects of cell physiology and has been proposed as a therapeutic target for Alzheimer's disease (AD). Here, we characterize a PLD mutant, pld-1, using the Caenorhabditis elegans animal model. We show that pld-1 animals present decreased phosphatidic acid levels, that PLD is the only source of total PLD activity and that pld-1 animals are more sensitive to the acute effects of ethanol. We further show that PLD is not essential for survival or for the normal performance in a battery of behavioral tests. Interestingly, pld-1 animals present both increased size and lipid stores levels. While ablation of PLD has no important effect in worm behavior, its ablation in an AD-like model that overexpresses amyloid-beta (Aβ), markedly improves various phenotypes such as motor tasks, prevents susceptibility to a proconvulsivant drug, has a protective effect upon serotonin treatment and reverts the biometric changes in the Aβ animals, leading to the normalization of the worm body size. Overall, this work proposes the C. elegans model as a relevant tool to study the functions of PLD and further supports the notion that PLD has a significant role in neurodegeneration.We would like to thank members of the Oliveira and Maciel labs for discussions, for critical analysis of data and discussions on the manuscript. Ricardo Rosa for his technical assistance in lifespan assays and Carlos Bessa for his technical suggestions. Thanks to the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health – National Center for Research Resources, for some of the nematode strains. Costs with acquisition and transfer of genetic C. elegans models were covered by Tiago Gil Oliveira. This work was supported by grants from the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), the Portuguese Foundation for Science and Technology PD/BD/52286/2013 (Francisca Vaz Bravo) as well as NIH ADRC grant P50 AG008702 to Scott A. Small (project G.D.P.) and NIH grant R21 AG045020 to G.D.P.info:eu-repo/semantics/publishedVersio

By their words ye shall know them: Language abstraction and the likeability of describers

According to the linguistic category model (LCM), behaviour can be described at concrete (e.g. ‘Kath hit Kim’) and abstract (e.g. ‘Kath is aggressive’) levels. Variations in these levels convey information about the person being described and the relationship between that person and the describer. In the current research, we examined the power of language abstraction to create impressions of describers themselves. Results show that describers are seen as less likeable when they use abstract (vs. concrete) language to describe the negative actions of others. Conversely, impressions of describers are more favourable when they opt for abstract descriptions of others' positive behaviours. This effect is partially mediated by the attribution of a communicative agenda to describers. By virtue of these attributional implications, language abstraction is an impression formation device that can impact on the reputation of describers

The ACS Nearby Galaxy Survey Treasury IV. The Star Formation History of NGC 2976

We present resolved stellar photometry of NGC 2976 obtained with the Advanced Camera for Surveys (ACS) as part of the ACS Nearby Galaxy Survey Treasury (ANGST) program. The data cover the radial extent of the major axis of the disk out to 6 kpc, or ~6 scale lengths. The outer disk was imaged to a depth of M_F606W ~ 1, and an inner field was imaged to the crowding limit at a depth of M_F606W ~ -1. Through detailed analysis and modeling of these CMDs we have reconstructed the star formation history of the stellar populations currently residing in these portions of the galaxy, finding similar ancient populations at all radii but significantly different young populations at increasing radii. In particular, outside of the well-measured break in the disk surface brightness profile, the age of the youngest population increases with distance from the galaxy center, suggesting that star formation is shutting down from the outside-in. We use our measured star formation history, along with H I surface density measurements, to reconstruct the surface density profile of the disk during previous epochs. Comparisons between the recovered star formation rates and reconstructed gas densities at previous epochs are consistent with star formation following the Schmidt law during the past 0.5 Gyrs, but with a drop in star formation efficiency at low gas densities, as seen in local galaxies at the present day. The current rate and gas density suggest that rapid star formation in NGC 2976 is currently in the process of ceasing from the outside-in due to gas depletion. This process of outer disk gas depletion and inner disk star formation was likely triggered by an interaction with the core of the M81 group >~1 Gyr ago that stripped the gas from the galaxy halo and/or triggered gas inflow from the outer disk toward the galaxy center.Comment: 22 pages, 14 figures, 2 tables, accepted for publication by Ap