68 research outputs found

    Comprehensive driving behavior model for intelligent transportation systems

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    This paper presents a novel approach of modeling human driving behavior in a more realistic way that can be effectively utilized in realizing intelligent transportation systems to ensure efficient, safe, secure and human-friendly vehicle control and transportations. A number of supporting systems based on individual driving behavior are identified. The proposed comprehensive driving model approximates complete behavior of individual drivers focusing not only the ideal steady and transient driving styles but also their natural variations. Simulation results and observations from real driving scenario illustrate the significance of the proposed model and its scopes

    Identifying the gene(s) that allow tigriopus californicus to survive under thermal stress

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    The copepod species, Tigriopus californicus, is one of the most thermally adaptable species in the biosphere. They have been found in tide pools from the coast of Alaska down to the coast of Southern California. However, as all other organisms have limits, the T. californicus are only able to tolerate temperatures up to 34ºC. By comparing gene expression between specimens exposed to high temperatures and those expressed to optimal temperatures, we identified the genes responsible for conferring tolerance to increasing temperatures. After testing gene expression between copepods at 20ºC and at 34ºC, we have determined that both the hsp70 gene and the toll-like receptors of the T. californicus play a role in tolerance to temperature variance.L’espèce copépode, Tigriopus californicus, est une des espèces les plus thermiquement adaptables de la biosphère. On les trouve dans les bâches depuis la côte de l’Alaska jusqu’à la côte sud de la Californie. Toutefois, comme tous les autres organ¬ismes, les Tigriopus californicus ont des limites et ne peuvent pas tolérer des températures supérieures à 34oC. En comparant l’expression génétique entre les spécimens exposés à des températures élevées et ceux exposés à des températures optimales, nous avons identifié les gènes responsables de la tolérance à des températures en hausse. Après avoir testé l’expression génétique entre les copépodes à 20oC et à 34oC, nous avons déterminé que le gène hsp70 et les récepteurs de type Toll du T. californicus jouent tous deux un rôle dans la tolérance aux variations de température

    A gene-based SNP resource and linkage map for the copepod Tigriopus californicus

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    <p>Abstract</p> <p>Background</p> <p>As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. <it>Tigriopus californicus </it>is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct a linkage map dense enough for quantitative trait locus detection in an interval mapping framework for <it>T. californicus--</it>a first for copepods.</p> <p>Results</p> <p>One hundred and ninety Single Nucleotide Polymorphisms (SNPs) were used to genotype our mapping population of 250 F<sub>2 </sub>larvae. We were able to construct a linkage map with an average intermarker distance of 1.8 cM, and a maximum intermarker distance of 10.3 cM. All markers were assembled into linkage groups, and the 12 linkage groups corresponded to the 12 known chromosomes of <it>T. californicus</it>. We estimate a total genome size of 401.0 cM, and a total coverage of 73.7%. Seventy five percent of the mapped markers were detected in 9 additional populations of <it>T. californicus</it>. Of available model arthropod genomes, we were able to show more colocalized pairs of homologues between <it>T. californicus </it>and the honeybee <it>Apis mellifera</it>, than expected by chance, suggesting preserved macrosynteny between Hymenoptera and Copepoda.</p> <p>Conclusions</p> <p>Our study provides an abundance of linked markers spanning all chromosomes. Many of these markers are also found in multiple populations of <it>T. californicus</it>, and in two other species in the genus. The genomic resource we have developed will enable mapping throughout the geographical range of this species and in closely related species. This linkage map will facilitate genome sequencing, mapping and assembly in an ecologically and taxonomically interesting group for which genomic resources are currently under development.</p

    Application of the rainbow trout derived intestinal cell line (RTgutGC) for ecotoxicological studies: molecular and cellular responses following exposure to copper.

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    There is an acknowledged need for in vitro fish intestinal model to help understand dietary exposure to chemicals in the aquatic environment. The presence and use of such models is however largely restrictive due to technical difficulties in the culturing of enterocytes in general and the availability of appropriate established cell lines in particular. In this study, the rainbow trout (Oncorhynchus mykiss) intestinal derived cell line (RTgutGC) was used as a surrogate for the "gut sac" method. To facilitate comparison, RTgutGC cells were grown as monolayers (double-seeded) on permeable Transwell supports leading to a two-compartment intestinal model consisting of polarised epithelium. This two-compartment model divides the system into an upper apical (lumen) and a lower basolateral (portal blood) compartment. In our studies, these cells stained weakly for mucosubstances, expressed the tight junction protein ZO-1 in addition to E-cadherin and revealed the presence of polarised epithelium in addition to microvilli protrusions. The cells also revealed a comparable transepithelial electrical resistance (TEER) to the in vivo situation. Importantly, the cell line tolerated apical saline (1:1 ratio) thus mimicking the intact organ to allow assessment of uptake of compounds across the intestine. Following an exposure over 72 h, our study demonstrated that the RTgutGC cell line under sub-lethal concentrations of copper sulphate (Cu) and modified saline solutions demonstrated uptake of the metal with saturation levels comparable to short term ex situ gut sac preparations. Gene expression analysis revealed no significant influence of pH or time on mRNA expression levels of key stress related genes (i.e. CYP3A, GST, mtA, Pgp and SOD) in the Transwell model. However, significant positive correlations were found between all genes investigated suggesting a co-operative relationship amongst the genes studied. When the outlined characteristics of the cell line are combined with the division of compartments, the RTgutGC double seeded model represents a potential animal replacement model for ecotoxicological studies. Overall, this model could be used to study the effects and predict aquatic gastrointestinal permeability of metals and other environmentally relevant contaminants in a cost effective and high throughput manner
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