1,698 research outputs found
KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea
High energy neutrinos produced in astrophysical processes will allow for a
new way of studying the universe. In order to detect the expected flux of high
energy neutrinos from specific astrophysical sources, neutrino telescopes of a
scale of a km^3 of water will be needed. A Northern Hemisphere detector is
being proposed to be sited in a deep area of the Mediterranean Sea. This
detector will provide complimentary sky coverage to the IceCube detector being
built at the South Pole. The three neutrino telescope projects in the
Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design,
and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a
3-year Design Study; the status of the Design Study is presented and some
technical issues are discussed.Comment: 4 pages, 3 figures, Prepared for the 10th International Conference on
Astroparticle and Underground Physics (TAUP 2007), Sendai, Japan, 11-15 Sep
200
Stigma development in Nicotiana tabacum. Cell death in transgenic plants as a marker to follow cell fate at high resolution
Sublethal toxicant effects with dynamic energy budget theory: model formulation
We develop and test a general modeling framework to describe the sublethal effects of pollutants by adding toxicity modules to an established dynamic energy budget (DEB) model. The DEB model describes the rates of energy acquisition and expenditure by individual organisms; the toxicity modules describe how toxicants affect these rates by changing the value of one or more DEB parameters, notably the parameters quantifying the rates of feeding and maintenance. We investigate four toxicity modules that assume: (1) effects on feeding only; (2) effects on maintenance only; (3) effects on feeding and maintenance with similar values for the toxicity parameters; and (4) effects on feeding and maintenance with different values for the toxicity parameters. We test the toxicity modules by fitting each to published data on feeding, respiration, growth and reproduction. Among the pollutants tested are metals (mercury and copper) and various organic compounds (chlorophenols, toluene, polycyclic aromatic hydrocarbons, tetradifon and pyridine); organisms include mussels, oysters, earthworms, water fleas and zebrafish. In most cases, the data sets could be adequately described with any of the toxicity modules, and no single module gave superior fits to all data sets. We therefore propose that for many applications, it is reasonable to use the most general and parameter sparse module, i.e. module 3 that assumes similar effects on feeding and maintenance, as a default. For one example (water fleas), we use parameter estimates to calculate the impact of food availability and toxicant levels on the long term population growth rate
Cytoskeletal dynamics of Cytotoxic T cells during migration in the tumour microenvironment
Typically, migrating T cells display an elongated polarized shape with a very dynamic leading edge and a uropod in the rear. This ‘amoeboid’ movement guarantees a fast migration driven by the formation of polarized protrusions at the front. The actomyosin cytoskeleton is responsible for the generation of the forces that are involved in this process. This thesis aims to determine what is the effect of T cell migration when different components of the actomyosin cortex were inhibited using a pharmacological approach. We found that the inhibition of each component of the actomyosin cortex, T cells display different conformation of the actin filaments and produce different type of protrusion. Furthermore, T cell migration is an important feature for the killing and clearance of canner cells. It has been reported that T cells can migrate efficiently in any kind of tissue whilst scanning for cognate antigen. On the other hand, it is known that the tumor microenvironment secretes immunosuppressive cytokines such as TGF-β impairing the antitumor activity of T cells. Therefore, we aim to determine how TGF-β affects the migration behavior of T cells and its consequences in the scanning strategy to search their cognate antigen
Design and Evaluation of a Protocol to Assess Electronic Travel Aids for Persons Who Are Visually Impaired
Design and Evaluation of a Protocol to Assess Electronic Travel Aids for Persons Who Are Visually Impaired
This study evaluated a protocol that was developed to assess how beneficial electronic travel aids are for persons who are visually impaired. Twenty persons with visual impairments used an electronic travel device (Trekker) for six weeks to conform to the protocol, which proved useful in identifying successful users of the device.</p
Design and Evaluation of a Protocol to Assess Electronic Travel Aids for Persons Who Are Visually Impaired
Small-scale blowouts in coastal dunes (2):Habitat factors and restoration measures for aeolian dynamics
- …