1,803 research outputs found
Investigation of additives for improvement of adhesive and elastomer performance Final report
Improvement additives for adhesive and elastomer performanc
The Mercury-Redstone project
Mercury-Redstone project development history, and contributions to future manned spacecraft design and operatio
Strategic planning for temporary housing : 1999 earthquakes in Turkey
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal
Application of composite hydrogels to control physical properties in tissue engineering and regenerative medicine
The development of biomaterials for the restoration of the normal tissue structure–function relationship in pathological conditions as well as acute and chronic injury is an area of intense investigation. More recently, the use of tailored or composite hydrogels for tissue engineering and regenerative medicine has sought to bridge the gap between natural tissues and applied biomaterials more clearly. By applying traditional concepts in engineering composites, these hydrogels represent hierarchical structured materials that translate more closely the key guiding principles required for improved recovery of tissue architecture and functional behavior, including physical, mass transport, and biological properties. For tissue-engineering scaffolds in general, and more specifically in composite hydrogel materials, each of these properties provide unique qualities that are essential for proper augmentation and repair following disease and injury. The broad focus of this review is on physical properties in particular, static and dynamic mechanical properties provided by composite hydrogel materials and their link to native tissue architecture and, ultimately, tissue-specific applications for composite hydrogels
Co-producing knowledge to address disaster risks in informal settlements in Dar es Salaam, Tanzania: pathways toward urban equality?
In Dar es Salaam, Tanzania, small-scale and everyday disasters are a manifestation of the multidimensional inequalities faced by residents of informal settlements. The co-production of knowledge about disaster and other risks, bringing together residents with local NGOs and local government representatives, is a potential entry point for addressing inequalities. This paper reports on such a co-production process in two informal settlements, carried out by the Centre for Community Initiatives with the Tanzania Urban Poor Federation and local government at the Mtaa level, and it looks at how community assessments of risks travel into local governance and policymaking. The involvement of Mtaa officials in this process has led to incremental changes in local governance, for example better linking of local budgets with disaster risk reduction (DRR) priorities and the representation of civil society on the municipal disaster management committees. The paper also points to the challenges of achieving integration of DRR and development activities at the local level
Ras-dependent and Ras-independent effects of PI3K in Drosophila motor neurons
The lipid kinase PI3K plays key roles in cellular responses to activation of receptor tyrosine kinases or G protein coupled receptors such as the metabotropic glutamate receptor (mGluR). Activation of the PI3K catalytic subunit p110 occurs when the PI3K regulatory subunit p85 binds to phosphotyrosine residues present in upstream activating proteins. In addition, Ras is uniquely capable of activating PI3K in a p85-independent manner by binding to p110 at amino acids distinct from those recognized by p85. Because Ras, like p85, is activated by phosphotyrosines in upstream activators, it can be difficult to determine if particular PI3K-dependent processes require p85 or Ras. Here we ask if PI3K requires Ras activity for either of two different PI3K-regulated processes within Drosophila larval motor neurons. To address this question, we determined the effects on each process of transgenes and chromosomal mutations that decrease Ras activity, or mutations that eliminate the ability of PI3K to respond to activated Ras. We found that PI3K requires Ras activity to decrease motor neuron excitability, an effect mediated by ligand activation of the single Drosophila mGluR DmGIuRA. In contrast, the ability of PI3K to increase synaptic bouton number is Ras independent. These results suggest that distinct regulatory mechanisms underlie the effects of PI3K on distinct phenotypic outputs. We additionally found that the glutamate-activation of DmGIuRA initiates ERK signaling; however the signaling intermediates linking DmGIuRA to this kinase cascade are unknown
The roles of charge exchange and dissociation in spreading Saturn's neutral clouds
Neutrals sourced directly from Enceladus's plumes are initially confined to a
dense neutral torus in Enceladus's orbit around Saturn. This neutral torus is
redistributed by charge exchange, impact/photodissociation, and neutral-neutral
collisions to produce Saturn's neutral clouds. Here we consider the former
processes in greater detail than in previous studies. In the case of
dissociation, models have assumed that OH is produced with a single speed of 1
km/s, whereas laboratory measurements suggest a range of speeds between 1 and
1.6 km/s. We show that the high-speed case increases dissociation's range of
influence from 9 to 15 Rs. For charge exchange, we present a new modeling
approach, where the ions are followed within a neutral background, whereas
neutral cloud models are conventionally constructed from the neutrals' point of
view. This approach allows us to comment on the significance of the ions'
gyrophase at the moment charge exchange occurs. Accounting for gyrophase: (1)
has no consequence on the H2O cloud; (2) doubles the local density of OH at the
orbit of Enceladus; and (3) decreases the oxygen densities at Enceladus's orbit
by less than 10%. Finally, we consider velocity-dependent, as well as
species-dependent cross sections and find that the oxygen cloud produced from
charge exchange is spread out more than H2O, whereas the OH cloud is the most
confined.Comment: Accepted to the Journal of Geophysical Research, 49 pages, 10 figure
Изменение психических состояний педагогов в процессе профессиональной деятельности с учетом стажа деятельности
It is relatively unknown how different dietary components, in partnership, regulate gene expression linked to colon pathology. It has been suggested that the combination of various bioactive components present in a plant-based diet is crucial for their potential anticancer activities. This study employed a combinatorial chemopreventive strategy to investigate the impact of selenium and/or isothiocyanates on DNA methylation processes in colorectal carcinoma cell lines
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