806 research outputs found
GAP-independent functions of DLC1 in metastasis.
Metastases are responsible for most cancer-related deaths. One of the hallmarks of metastatic cells is increased motility and migration through extracellular matrixes. These processes rely on specific small GTPases, in particular those of the Rho family. Deleted in liver cancer-1 (DLC1) is a tumor suppressor that bears a RhoGAP activity. This protein is lost in most cancers, allowing malignant cells to proliferate and disseminate in a Rho-dependent manner. However, DLC1 is also a scaffold protein involved in alternative pathways leading to tumor and metastasis suppressor activities. Recently, substantial information has been gathered on these mechanisms and this review is aiming at describing the potential and known alternative GAP-independent mechanisms allowing DLC1 to impair migration, invasion, and metastasis formation
VEGETATION MANAGEMENT APPROACHES FOR REDUCING WILDLIFE-AIRCRAFT COLLISIONS
Wildlife-aircraft collisions (wildlife strikes) pose safety risks to aircraft and cost civil aviation over $390 million annually in the USA. We reviewed the results of prior studies to summarize the vegetation management techniques that have proven effective for wildlife strike reduction or have shown potential for achieving the same goal. Habitat components that may affect wildlife use of airports include food, cover, water, and loafing areas. Improperly managed natural and ornamental vegetation on airports can be important attractants for wildlife that pose strike hazards. However, effective vegetation management can reduce these hazards. Maintaining tall herbaceous vegetation may reduce the availability or attractiveness of loafing and feeding sites for some species of birds such as gulls. However, this management strategy may also increase cover and food resources for other hazardous species. Thus, optimum vegetation height management strategies require further research and may be site-specific. Food availability may be reduced by replacing attractive vegetation such as palatable forage with less attractive vegetation. Vegetation management may also include removal of vegetative cover for deer and small mammals and nesting sites for birds such as woody vegetation. Removal of ornamental trees and shrubs may also be used to reduce availability of perches for flocking birds and large predatory birds. Despite more than 30 years of substantive discussion on the importance of these habitat management techniques, few reliable studies of the effectiveness of these techniques have been conducted. Specific needs for reliable data include definitive studies of the response of entire bird communities to vegetation height management in the USA, and field evaluations of vegetation types thought to be unattractive to wildlife under operational airport conditions
VEGETATION MANAGEMENT APPROACHES FOR REDUCING WILDLIFE-AIRCRAFT COLLISIONS
Wildlife-aircraft collisions (wildlife strikes) pose safety risks to aircraft and cost civil aviation over $390 million annually in the USA. We reviewed the results of prior studies to summarize the vegetation management techniques that have proven effective for wildlife strike reduction or have shown potential for achieving the same goal. Habitat components that may affect wildlife use of airports include food, cover, water, and loafing areas. Improperly managed natural and ornamental vegetation on airports can be important attractants for wildlife that pose strike hazards. However, effective vegetation management can reduce these hazards. Maintaining tall herbaceous vegetation may reduce the availability or attractiveness of loafing and feeding sites for some species of birds such as gulls. However, this management strategy may also increase cover and food resources for other hazardous species. Thus, optimum vegetation height management strategies require further research and may be site-specific. Food availability may be reduced by replacing attractive vegetation such as palatable forage with less attractive vegetation. Vegetation management may also include removal of vegetative cover for deer and small mammals and nesting sites for birds such as woody vegetation. Removal of ornamental trees and shrubs may also be used to reduce availability of perches for flocking birds and large predatory birds. Despite more than 30 years of substantive discussion on the importance of these habitat management techniques, few reliable studies of the effectiveness of these techniques have been conducted. Specific needs for reliable data include definitive studies of the response of entire bird communities to vegetation height management in the USA, and field evaluations of vegetation types thought to be unattractive to wildlife under operational airport conditions
Inhibition of cell migration and invasion mediated by the TAT-RasGAP317-326 peptide requires the DLC1 tumor suppressor.
TAT-RasGAP317-326, a peptide corresponding to the 317-326 sequence of p120 RasGAP coupled with a cell-permeable TAT-derived peptide, sensitizes the death response of various tumor cells to several anticancer treatments. We now report that this peptide is also able to increase cell adherence, prevent cell migration and inhibit matrix invasion. This is accompanied by a marked modification of the actin cytoskeleton and focal adhesion redistribution. Interestingly, integrins and the small Rho GTP-binding protein, which are well-characterized proteins modulating actin fibers, adhesion and migration, do not appear to be required for the pro-adhesive properties of TAT-RasGAP317-326. In contrast, deleted in liver cancer-1, a tumor suppressor protein, the expression of which is often deregulated in cancer cells, was found to be required for TAT-RasGAP317-326 to promote cell adherence and inhibit migration. These results show that TAT-RasGAP317-326, besides its ability to favor tumor cell death, hampers cell migration and invasion
Living small-sized (63-150 µm) foraminifera from mid-shelf to mid-slope environments in the Bay of Bisca
Live (rose Bengal stained) foraminiferal faunas of the 63–150 μm size fraction have been investigated in surficial sediment (0–1 cm) from mid-shelf to mid-slope environments in the Bay of Biscay. Eleven stations were sampled in April 2002 and March 2004 between 80 and 2000 m water depth (mwd). Earlier studies on the temporal variability of phytoplankton primary production suggest that our stations were sampled at the most eutrophic period of the year. In response to the decrease of exported organic matter flux to the seafloor along our bathymetric transect, foraminiferal standing stocks decrease from ~1400–2000 specimens per 50 cm3 on the continental shelf (100–140 mwd) and upper slope (550 mwd) to about 400 specimens per 50 cm3 at mid-slope stations (2000 mwd). At all stations, the faunas contain an important amount of small opportunistic species that are favored by seasonal phytodetritus input. On the continental shelf where phytoplankton bloom, events may be geographically restricted; the foraminiferal response is dependent on the distance to the surface-water primary-production cells. Textularia porrecta is very abundant at an 80-m-deep station that is close to the coast and characterized by a high sedimentation rate of fine-grained particles. Foraminiferal faunas are dominated by Nonionella iridea, Cassidulina carinata and Bolivina ex. gr. dilatata at the outer-shelf stations (110–140 mwd) that are under the direct influence of spring bloom phytodetritus input in the northern Bay of Biscay. A fauna dominated by Bolivina dilatata/spathulata and Bolivina subaenariensis is found in the southeastern Bay of Biscay at a 140-m-deep outer-shelf station located seaward of the Adour River estuary, where the sediment is probably enriched in terrestrial organic matter. Apparently, differences in foraminiferal composition between outer-shelf areas in the northern and southeastern Bay of Biscay are related to differences in organic matter quality. On the continental slope, a bathymetric zonation of taxa is observed from upper-slope sites (550–1000 mwd) rich in Epistominella exigua and Uvigerina peregrina to mid-slope stations (1600–2000 mwd), where Nuttallides pusillus and Gavelinopsis translucens dominate the small-sized living fauna. This bathymetric foraminiferal zonation probably reflects a trophic gradient between upper-slope eutrophic stations and mid-slope, more oligotrophic sites. Our zonal description of small-sized living foraminifera (63–150 μm) is new for the Bay of Biscay and may provide the basis to reconstruct former export production regimes in marginal paleo-environments from temperate latitude areas
Renforcer la participation politique : une approche évaluative du projet du Bureau lausannois pour les immigrés "Votre Ville, Votre Vie, Votre Voix"
Ce mémoire de recherche a pour thématique la participation politique, dans son acception large. Celle-ci est abordée sous un angle novateur, celui des politiques publiques. Les objectifs sont, d'une part, de déterminer les mécanismes mis en place pour renforcer la participation politique et, d'autre part, d'en évaluer les impacts. L'étude consiste en une étude de cas du projet « Votre Ville, Votre Vie, Votre Voix » développé par le Bureau lausannois pour les immigrés. Plus précisément, deux sortes d'activités menées entre mars et juin 2014 dans le cadre de ce projet ont été sélectionnées pour l'évaluation : une séance d'information sur les droits politiques et des visites d'institutions politiques. Pour ce faire, une dizaine de participants à ces activités ont été interviewés. Les résultats de l'étude mettent en évidence des impacts marqués sur les facteurs de la participation politique liés aux affects ou aux opinions et des impacts moins nets sur la compétence politique et sur les différentes composantes du comportement politique. Ces différents effets ressortent enfin plus clairement chez les interviewés ayant participé aux visites qu'à la séance
Are birds scared by rotating mirrors?
Blackbirds (Icteridae) create human health and safety concerns when roosting in large numbers near airports or other urban areas. Therefore, there is considerable demand for effective nonlethal techniques to deter these birds. We tested the effectiveness of rotating mirrors (Peaceful Pyramid®) to keep blackbirds away from decoy traps. Mirrors were in place on traps for 5 consecutive days with control traps having similar a device in place but without mirrors. The total number of birds captured in traps with clear mirrors and control traps did not (P = 0.62) differ. When red mirrors were used, the total number of birds captured was lower (P = 0.01) in treated than control traps. Similar (P ≥ 0.42) numbers of brown-headed cowbirds (Molothrus ater) were caught in control or traps treated with either clear or red mirrors. Fewer (P = 0.01) common grackles (Quiscalus quiscula) were captured in traps with red mirrors as compared to control traps. Under the test criteria (i.e., food and flock attractants), Peaceful Pyramids®did not reduce the number of cowbirds captured in decoy traps. However, fewer birds, specifically common grackles, were captured at traps with red mirrors; we conclude that there was at least a species-specific initial reaction to red mirror
Influence of model based iterative reconstruction algorithm on image quality of multiplanar reformations in reduced dose chest CT.
Model-based iterative reconstruction (MBIR) reduces image noise and improves image quality (IQ) but its influence on post-processing tools including maximal intensity projection (MIP) and minimal intensity projection (mIP) remains unknown.
To evaluate the influence on IQ of MBIR on native, mIP, MIP axial and coronal reformats of reduced dose computed tomography (RD-CT) chest acquisition.
Raw data of 50 patients, who underwent a standard dose CT (SD-CT) and a follow-up RD-CT with a CT dose index (CTDI) of 2-3 mGy, were reconstructed by MBIR and FBP. Native slices, 4-mm-thick MIP, and 3-mm-thick mIP axial and coronal reformats were generated. The relative IQ, subjective IQ, image noise, and number of artifacts were determined in order to compare different reconstructions of RD-CT with reference SD-CT.
The lowest noise was observed with MBIR. RD-CT reconstructed by MBIR exhibited the best relative and subjective IQ on coronal view regardless of the post-processing tool. MBIR generated the lowest rate of artefacts on coronal mIP/MIP reformats and the highest one on axial reformats, mainly represented by distortions and stairsteps artifacts.
The MBIR algorithm reduces image noise but generates more artifacts than FBP on axial mIP and MIP reformats of RD-CT. Conversely, it significantly improves IQ on coronal views, without increasing artifacts, regardless of the post-processing technique
Gulls
Abundant gull (Figure 1) populations in North America have led to a variety of conflicts with people. Gulls cause damage at aquaculture facilities and other properties, and often collide with aircraft. Their use of structures on and near water results in excessive amounts of bird droppings on boats and docks. Their presence near outdoor dining establishments, swimming beaches, and recreational sites can lead to negative interactions with people. Large amounts of gull fecal material pollutes water and beaches resulting in drinking water contamination and swim bans. A combination of dispersal techniques, exclusion and limited lethal control may reduce damage to an acceptable level.
No single management method to prevent gull conflicts works all the time or in all settings. Wildlife management methods should be integrated so that one method enhances the effect of another. For example, frightening devices often are more effective when done in conjunction with habitat modification (e.g., removal of food resources or roosting habitat) to make a site less attractive to gulls. Likewise, exclusion devices, such as overhead wires, work better when combined with covering or removing food resources.
Gulls are classified as a migratory bird species and are protected by federal and, in most cases, state laws. In the United States, gulls may be taken only with a permit issued by the U.S. Fish and Wildlife Service. Occasionally, an additional permit is required from the state wildlife management agency. Permits are issued only after dispersal and other non-lethal damage management methods have been employed and proven ineffective at resolving the conflicts. No federal permit is needed, however, to frighten or mechanically exclude gulls
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