No description available.

Mycolic acids, the characteristic, abundant waxes of the cell wall of Mycobacteria were purified by Counter Current Distribution (CCD) from alkaline methanolytic crude extracts of bacteria, aiming at investigating their role in eliciting immune responses. Crude mycobacterial cell-wall extracts were first made by saponification in potassium hydroxide methanol solution. Purification was then performed with CCD using a bi-phasic tricomponent system, consisting of double distilled deionized water (dddH2O), chloroform and methanol. Emulsions were formed in this system which in turn extended the purification time. The addition of a preliminary funnel extraction step, to reduce the saponified fatty acids in the crude extract, before CCD and the addition of NaCI as an emulsions breaker in the CCD solvent system, produced a high yield of pure mycolic acids. The purity of these mycolic acids were assessed using reversed-phase HPLC-analysis. This method proved not only to be applicable to purify mycolic acids from M. tuberculosis but was also applicable in purifying mycolic acids from other sources, such as M. vaccae. The immunogenic properties of the purified mycolic acids were confirmed in experiments in which they induced the formation of antibodies in Sprague-Dawley rats when immunized in Marcol 52 oil. The antibody response was monitored by ELISA after 3 months of repeated immunization every second week. A dose-related response was observed for the induction of antibodies specific for mycolic acids, immobilized on the ELISA plates. Mycolic acids also appeared to influence adjuvant arthritis. Pure mycolic acids, suspended in mineral oil were administered intradermally into Lewis rats one week before the intradermal administration of an arthritis-inducing dose of lyophilized M. tuberculosis H37Ra. Animals receiving Mycobacteria, but no mycolic acids treatment, developed severe symptoms of arthritis within two weeks after bacterial challenge. No arthritis symptoms were apparent in mycolic acids treated rats. Mycolic acids treatment alone, did not produce arthritis. Mycolic acids pre-treatment of M. tuberculosis H37Rv-infected mice, rendered tuberculosis susceptible Balb/c mice more resistant. This resistance was equivalent to that observed in tuberculosis resistant C57Bl/6 mice. Post-infection treatment of M. tuberculosis H37Rv-infected mice with MA had no effect. Resistance of C57Bl/6 mice is commonly associated with the expression of IL-12 and IFN-ã. The effect of mycolic acids in the spleens of M. tuberculosis-infected Balb/c mice was investigated. It was observed that there was no significant change on the THI and TH2 cytokines. The absence of mycolic acids-induced THI/TH2 cytokine bias implied that protection was not provided by the expression of IL-12 and IFN-ã in the spleen. These results support the hypothesis that mycolic acids are immunogenic in respect of being able to induce specific antibodies, to provide resistance against tuberculosis and to prevent the development of adjuvant arthritis. The mechanism by which mycolic acids perform these tasks is unknown, particularly in these rodent models, which differ from humans, in that they do not have the CD1b that presents mycolic acids in humans. Unravelling this mechanism, can possibly aid the development of a pharmaceutical formulation that introduces MA into the body to enhance resistance to TB and prevent arthritis as an associated side-reaction. / Dissertation (MSc)--University of Pretoria, 2010. / Biochemistry / unrestricted

Indiana University-Purdue University Indianapolis (IUPUI) / Some individuals with alcohol use disorder (AUD) continue to drink because they have developed a habit in which they are not considering the consequences of their actions. Habitual actions persist despite changes in reward and are often studied using devaluation procedures. Stress hormones, such as corticotropin releasing factor (CRF), have been linked to AUD when examining binge-like drinking and withdrawal in rodents. Stress has been examined in the switch from goal-directed to habitual behavior, and CRF has often mimicked the effects of stress exposure. This study looked at the possible direct effects of CRF on habit expression in rats using an operant paradigm. Finding possible novel mechanisms of habit could create an avenue for future novel treatment options. Female and male Long Evans rats were trained on a variable interval schedule using sucrose as a reward. Rats then underwent devaluation procedures including both sensory-specific satiety and conditioned taste aversion (CTA) to test for habitual behaviors. Prior to an extinction session post-CTA, animals were treated with either 20 mg/kg R121919, a CRF1 receptor antagonist, or vehicle. A second extinction session was conducted where animals received the alternative treatment. Lever presses were recorded as a measure of goal-directed or habitual behavior. Sensory-specific satiety devaluation tests revealed that animals were not sensitive to devaluation. This was further supported by both post-CTA extinction sessions. R121919 had no effect on lever pressing in either devalued or valued groups. Further research is needed to explore how a CRF receptor antagonist may affect habit formation or the transition from goal-directed to habit behaviors. Future studies should also examine any possible interaction effects CRF may have with alcohol or stress on habitual behaviors.

No description available.

Small mammal population dynamics and community structure were studied in three East Central Florida communities. The communities were compared as distinct stages of a sand pine scrub sere. The small mammals live-trapped with greatest frequency in this 3852 trap-night study were all cricetine rodents, Peromyscus polionotus niveiventris (beach mouse), Sigmodon hispidus littoralis (cotton rat), and Peromyscus gossypinus palmarius (cotton mouse). Population numbers, survival, body weights, hind foot lengths, age structure, sex ratios, reproductive cycles, and movements were discussed for each of three species mentioned. These data will serve as a baseline information for ecological monitoring studies associated with NASA Space Shuttle operations. Small mammal community structure was examined with regard to interspecific spatial overlap and body size ratios. Vegetation density was compared within and among the study sites. Within study sites vegetation density appeared to influence mammal microhabitat selection. Among study sites a highly significant correlation was found between small mammal species diversity and vegetation density.

It has been estimated that approximately 300,000 Canadians are afflicted with schizophrenia (SCZ). Due to the severity of symptoms as well as critical age of onset, the quality of life among SCZ patients can be poor; thus, further therapeutic research is of great interest. In addition to the more-common rodent models of SCZ (amphetamine sensitization, PCP sensitization, etc.), our lab has proposed the medial prefrontal cortex (mPFC) synapsin-II knockdown (KD) model. Prior to this study, the cognitive effects of mPFC synapsin-II KD had yet to be reported. Using a 14-day continuous infusion of antisense (AS) deoxyoligonucleotides for synapsin-II to the mPFC, the results of the KD model have been recreated for further study. The 5-choice-serial-reaction-time-task was utilized to determine the effects of mPFC synapsin-II KD on attention and vigilance. In addition to reductions in both PPI (p<0.05) and social interaction (p<0.05), as well as hyper-locomotion (p<0.05); rats treated with synapsin II AS performed significantly worse on the 5-CSRTT than did control (mismatch/aCSF) animals. The AS animals were significantly less likely to make correct responses (p<0.001), and significantly more likely to commit omissions (p<0.0001) and perseverative responses (p<0.05) than were control animals. Additionally, an [18F]FDG tracer and PET/CT scans were used to determine differences in brain metabolism due to synapsin-II KD. Results revealed significant reductions in [18F]FDG among AS treated rats (p<0.05) when compared to control animals. This reduction appeared to be a global result, however it followed 13-days of treatment which may account for the widespread effect. The mPFC synapsin-II KD model of SCZ has showcased cognitive and metabolic effects similar to that of SCZ. These findings, in conjunction with past research, provide evidence for the synapsin-II KD model as a viable rodent model of SCZ. Further research utilizing this model will provide valuable insight into the pathogenesis of SCZ and potential therapeutics. / Thesis / Master of Health Sciences (MSc)

Laboratory experiments have suggested that the coexistence of certain heteromyid rodent species is facilitated through differential use of seed dispersions (clump sizes). Field experiments with the Bannertail kangaroo rat, Dipodomys spectabilis, and Merriam's kangaroo rat, D. merriami, indicate their use of different clump sizes is not sufficiently specialized to permit coexistence. Field experiments based on the assumption that these species interact primarily through aggression demonstrated that during at least one season of the year D. spectabilis excludes the smaller D. merriami from its foraging range. Preliminary characterization of spatial heterogeneity of resource productivity implies that the competitive coexistence of these species is regional and is dependent upon the existence of areas with low productivity that are not economically usable by D. spectabilis. These areas of low productivity may serve as a competitive refuge for D. merriami, facilitating its persistence. A brief review of the evidence for the occurrence of competition between heteromyid species is presented, as is a selected review of the evidence supporting the various hypotheses explaining the competitive coexistence of heteromyid rodents.

<p>The purpose with this project was to invent a product that secures buildings sewer</p><p>systems against rats. The problem was presented to us by a local building maintainer in</p><p>Halmstad, who had experienced big problems with rats in his real estate. The project has</p><p>been carried out by Per Johansson, Robert Lidén and Niclas Nilsson under our own</p><p>auspices. We are primarily sponsored by AMLI Business Partner but also by</p><p>Innvationsgruppen, Halmstad Fastighets AB and Anticimex.</p><p>To be able to secure a whole building with only one product we came to the conclusion</p><p>that the product must be placed in the horizontal sewer pipe that connects with the</p><p>municipal sewer system. Our goal was to invent a product that prevent rats from passing</p><p>and at the same time not affect the water flow. We have succeeded in meeting our goal</p><p>and can in this report present a well functioning product named RatStop.</p><p>We have confirmed the market and can see a high potential in the product. The problem</p><p>is big in Sweden and enormous worldwide. The project group has to find sponsors for</p><p>production, marketing and further development of complementing concepts. Therefore</p><p>we now search for business partners.</p><p>We have used dynamic product development and all the tools combined with it during the</p><p>development. Especially meetings with competent persons have given us much, like</p><p>insight in the market, facts in different subjects and feedback on our idea and product.</p><p>We have learned a lot and we will benefit from this in the future. We believe in our</p><p>product and we will continue to work with it under the newly started company, Ratcon.</p><p>Hopefully our product will be available on the market within a year.</p>

The purpose with this project was to invent a product that secures buildings sewer systems against rats. The problem was presented to us by a local building maintainer in Halmstad, who had experienced big problems with rats in his real estate. The project has been carried out by Per Johansson, Robert Lidén and Niclas Nilsson under our own auspices. We are primarily sponsored by AMLI Business Partner but also by Innvationsgruppen, Halmstad Fastighets AB and Anticimex. To be able to secure a whole building with only one product we came to the conclusion that the product must be placed in the horizontal sewer pipe that connects with the municipal sewer system. Our goal was to invent a product that prevent rats from passing and at the same time not affect the water flow. We have succeeded in meeting our goal and can in this report present a well functioning product named RatStop. We have confirmed the market and can see a high potential in the product. The problem is big in Sweden and enormous worldwide. The project group has to find sponsors for production, marketing and further development of complementing concepts. Therefore we now search for business partners. We have used dynamic product development and all the tools combined with it during the development. Especially meetings with competent persons have given us much, like insight in the market, facts in different subjects and feedback on our idea and product. We have learned a lot and we will benefit from this in the future. We believe in our product and we will continue to work with it under the newly started company, Ratcon. Hopefully our product will be available on the market within a year.

No description available.