Identifying and Predicting Rat Behavior Using Neural Networks

The hippocampus is known to play a critical role in episodic memory function. Understanding the relation between electrophysiological activity in a rat hippocampus and rat behavior may be helpful in studying pathological diseases that corrupt electrical signaling in the hippocampus, such as Parkinson’s and Alzheimer’s. Additionally, having a method to interpret rat behaviors from neural activity may help in understanding the dynamics of rat neural activity that are associated with certain identified behaviors. In this thesis, neural networks are used as a black-box model to map electrophysiological data, representative of an ensemble of neurons in the hippocampus, to a T-maze, wheel running or open exploration behavior. The velocity and spatial coordinates of the identified behavior are then predicted using the same neurological input data that was used for behavior identification. Results show that a nonlinear autoregressive process with exogenous inputs (NARX) neural network can partially identify between different behaviors and can generally determine the velocity and spatial position attributes of the identified behavior inside and outside of the trained interva

Host responses to Antigens of Candida Albicans

Six different types of antigens were prepared from Candida albicans viz. whole cell homogenate (CAD-G), partially purified soluble mannan (M ), particulate mannan adsorbed onto latex particles (M+L) , purified cytoplasmic protein (PP), culture filtrate (CF) and killed whole cells (WC) . The stimulatory effects of these antigens were tested on peripheral blood lymphocytes of 20 normal human subjects by in vitro lymphocyte transformation tests. The order of stimulation capacities was CF > CAD-6 >WC >M+L>PP >M. Thus the crude antigens were found to be superior to purified and soluble preparations in promoting lymphocyte transformation. The LD50 of test strain of C. albicans (NCPF 3153) to "TO" strain mic e was estimated and calculated to be 1.52 x 10^6 blastospores. Seven groups of mice were immunized with the same antigens and challenged subsequently with a lethal dose of 4 x 10^6 live organisms . Live cells of C. albicans were also used to immunize mice before challenge. The agglutinin titres of the immunized animals ranged from 1:4 to 1:64. The group immunized with killed whole cells of Candida had highest agglutinin titres. The precipitin reactions were directed principally toward CA0-6 and purified cytoplasmic protein antigens. Different antigens conferred different degrees of protection in the following order: CAD-6 > M+L>CF>PP>WC(A) = M>WC(K) Heat killed vaccine (WC(K)) did not confer any measurable protection. Surviving animals showed agglutinin titres which ranged from 1:4 to 1:16 and precipitins which were directed primarily against CAD-6 and PP antigens. None of the groups showed any anti-mannan precipitins. Mice immunized with heat-killed hole cells of C. albicans and control animals showed the same responses to thigh muscle challenge with 5 x 10^8 live organisms. An abscess was formed which resolved spontaneously after 4 weeks with a cellular reaction mostly of polymorphonuclear cells. Candida was present mostly in the mycelial phase . Repeated thigh muscle challenge with live organisms produced local resistance manifested by accelerated sequestration of abscesses and the appearance of Candida mostly in yeast phase

Migraciones y derecho de asilo en la UE : terrorismo y securitización del estado : implicancias de las políticas adoptadas post 9/11

En esta tesis analizaremos el impacto que tuvo el atentado del 11 de septiembre en el discurso y las prácticas que regulan el flujo de Migraciones y el Derecho de Asilo en Europa, para luego señalar las contradicciones que se han dado con respecto a la protección de los derechos humanos contenidos en el Sistema Europeo Común de Asilo (SECA). El marco teórico que se empleará es el paradigma de ¨Securitización¨ para realizar un seguimiento de los procesos discursivos que han servido para establecer vínculos entre el terrorismo, la seguridad nacional, el flujo de migraciones y aquellos que invocan el derecho de asilo.. El análisis de la política de asilo contemporánea de la Unión Europea y las prácticas dan cuenta del grado en que la ¨Securitización¨ está presente en la formulación de políticas de asilo de la UE. Esto demuestra que, hasta que el paradigma de seguridad en este ámbito de actuación sea suplantado, la realización de un sistema de asilo basado en los derechos humanos no será posible

The Nc1/Endostatin Domain of Caenorhabditis elegans Type Xviii Collagen Affects Cell Migration and Axon Guidance

Type XVIII collagen is a homotrimeric basement membrane molecule of unknown function, whose COOH-terminal NC1 domain contains endostatin (ES), a potent antiangiogenic agent. The Caenorhabditis elegans collagen XVIII homologue, cle-1, encodes three developmentally regulated protein isoforms expressed predominantly in neurons. The CLE-1 protein is found in low amounts in all basement membranes but accumulates at high levels in the nervous system. Deletion of the cle-1 NC1 domain results in viable fertile animals that display multiple cell migration and axon guidance defects. Particular defects can be rescued by ectopic expression of the NC1 domain, which is shown to be capable of forming trimers. In contrast, expression of monomeric ES does not rescue but dominantly causes cell and axon migration defects that phenocopy the NC1 deletion, suggesting that ES inhibits the promigratory activity of the NC1 domain. These results indicate that the cle-1 NC1/ES domain regulates cell and axon migrations in C. elegans

Structural and Functional Evaluation of C. elegans Filamins FLN-1 and FLN-2

Filamins are long, flexible, multi-domain proteins composed of an N-terminal actin-binding domain (ABD) followed by multiple immunoglobulin-like repeats (IgFLN). They function to organize and maintain the actin cytoskeleton, to provide scaffolds for signaling components, and to act as mechanical force sensors. In this study, we used transcript sequencing and homology modeling to characterize the gene and protein structures of the C. elegans filamin orthologs fln-1 and fln-2. Our results reveal that C. elegans FLN-1 is well conserved at the sequence level to vertebrate filamins, particularly in the ABD and several key IgFLN repeats. Both FLN-1 and the more divergent FLN-2 colocalize with actin in vivo. FLN-2 is poorly conserved, with at least 23 IgFLN repeats interrupted by large regions that appear to be nematode-specific. Our results indicate that many of the key features of vertebrate filamins are preserved in C. elegans FLN-1 and FLN-2, and suggest the nematode may be a very useful model system for further study of filamin function

An Integrated Strategy to Study Muscle Development and Myofilament Structure in Caenorhabditis elegans

A crucial step in the development of muscle cells in all metazoan animals is the assembly and anchorage of the sarcomere, the essential repeat unit responsible for muscle contraction. In Caenorhabditis elegans, many of the critical proteins involved in this process have been uncovered through mutational screens focusing on uncoordinated movement and embryonic arrest phenotypes. We propose that additional sarcomeric proteins exist for which there is a less severe, or entirely different, mutant phenotype produced in their absence. We have used Serial Analysis of Gene Expression (SAGE) to generate a comprehensive profile of late embryonic muscle gene expression. We generated two replicate long SAGE libraries for sorted embryonic muscle cells, identifying 7,974 protein-coding genes. A refined list of 3,577 genes expressed in muscle cells was compiled from the overlap between our SAGE data and available microarray data. Using the genes in our refined list, we have performed two separate RNA interference (RNAi) screens to identify novel genes that play a role in sarcomere assembly and/or maintenance in either embryonic or adult muscle. To identify muscle defects in embryos, we screened specifically for the Pat embryonic arrest phenotype. To visualize muscle defects in adult animals, we fed dsRNA to worms producing a GFP-tagged myosin protein, thus allowing us to analyze their myofilament organization under gene knockdown conditions using fluorescence microscopy. By eliminating or severely reducing the expression of 3,300 genes using RNAi, we identified 122 genes necessary for proper myofilament organization, 108 of which are genes without a previously characterized role in muscle. Many of the genes affecting sarcomere integrity have human homologs for which little or nothing is known