Novelty and the running-induced feeding suppression

In adult rats, wheel introduction induces a temporary feeding suppression, which may be the result of either a conditioned taste avoidance induced by wheel running (Left & Grant, 1996), or an anorectic effect produced by running (Mueller, Loft, & Eikelboom, 1997). The first experiment investigated the effect of alternate-day wheel access on consumption of novel 32% sucrose solution in 36 adult male rats. The first group of rats had no wheel access, the second continuous wheel access, and the third alternate-day wheel access. Rats without wheel access consumed large amounts of sucrose from the first day. Both groups with wheel access had similar, almost complete and long-lasting, suppressed sucrose consumption. The suppression occurred on both wheel and home cage days in the rats with alternate-day wheel exposure. This suggests that the unconditioned effect of running (whether sickness or some positive affect), when paired with a novel food, induces conditioned taste avoidance. CS pre-exposure has been shown to reduce conditioned taste avoidance, possibly through latent inhibition (Lubow & Moore, 1959; Lubow, 1989). The second experiment investigated the effect of alternate-day wheel access on consumption of a familiar sucrose solution (rats were given 10 days sucrose pre-exposure) in a similar design. The rats with continuous wheel access showed only a mild and short-lived suppression of the sucrose solution

Neural and Behavioural Effects of the \u3cem\u3eGinkgo biloba\u3c/em\u3e Leaf Extract Egb 761

Numerous studies have documented the cognitive-enhancing effects of standardized Ginkgo biloba leaf extracts (Ginkgo) both in humans and in rodents. In addition to its antioxidant and platelet-activating factor inhibiting properties, Gingko has been shown to protect cellular membrane fluidity, to enhance cerebral blood flow and microcirculation, and to modulate cholinergic system functioning, properties that have been suggested to underlie its cognitive-enhancing effects. However, the possible neurogenic-enhancing effects of Ginkgo on adult hippocampal neurogenesis as a possible mechanism underlying its nootropic effects have not been evaluated. The experiments discussed in the present thesis assessed such a possibility. Chapter 1 reviews studies that have evaluated the nootropic effects of Ginkgo in humans and in rodents. The anti-stress properties of Ginkgo as well as several molecular mechanisms proposed to account for its beneficial effects on central nervous system functioning are also discussed. Experiments presented in Chapter 2 used c-Fos immunoreactivity to characterize functional activity in selected brain regions following acute oral (150 mg/kg) and intraperitoneal (2.5-25 mg/kg, i.p.) administration of Ginkgo. Both routes of administration increased c-Fos immunoreactivity in the insular cortext and amygdala. However, some additional regions including the nucleus accumbens and dentate gyrus showed increased c-Fos immunoreactivity only in response to parenteral administration. Experiments presented in Chapter 3 evaluated the possible neurogenic properties of Ginkgo. The anxiolytic effects of the extract using the elevated plus maze, light/dark emergencec and social interaction tests were also assessed. Acute administration of Ginkgo (2.5-25 mg/kg, i.p.) had neither stimulating nor depressive effects on cell proliferation in the adult dentate gyrus. Survival of newborn neurons in the dentate gyrus of adult male rats was also not affected by chronic Ginkgo administration. Furthermore, the results showed that chronic administration of Ginkgo treatment had neither anxiolytic nor anxiogenic properties; however acute administration of a high and moderate dose of Ginkgo induced anxiety in some measures. Experiments described in Chapter 4 investigated whether suppressed neurogenesis induced by corticosterone (CORT) treatment could be restored by Ginkgo co-treatment. The results revealed that survival of newborn cells was inhibited in the dorsal dentate gyrus of rats chronically treated with CORT; however, Ginkgo co-treatment did not buffer this effect. Finally, experiments described in Chapter 5 evaluated the cognitive-enhancing effects of Ginkgo on young adult male rats using a food-reinforced two-component double Y-maze task. Results showed that Ginkgo-treated rats reached the training criteria faster, and made fewer errors. Rats treated with Ginkgo during the learning phase made fewer working memory errors. However, neither acute nor chronic post-training treatment with Gingko enhanced spatial working memory. Taken together, the results of the present dissertation showed that Ginkgo increased c-Fos immunoreactivity in several brain structures involved in learning and memory. Moreover, Ginkgo enhanced acquisition and performance of a double-Y maze task, but did not offer any continued benefits in an already-learned working memory task. Interestingly, a dose of Ginkgo (13.75 mg/kg) that was found to improve cognitive functioned failed to promote either cell proliferation or cell survival in the adult dentate gyrus. It also failed to restore the suppressive effects of CORT on dentate gyrus cell survival. It is concluded that Ginkgo pre-treatment subtly enhances learning, but this effect is likely not related to a modulatory effect on adult hippocampal neurogenesis

Rotating the boards:corporate governance

Can companies resolve groupthink issues and improve their performance by turning over their boards more often, ask Mark Rogers and Amir Satvat

Residence time distribution in tubular flow vessels with multiple baffles

The residence time distribution in a tubular flow vessel with multiple baffles has been investigated. Length of sections between the baffles, orifice diameter to vessel diameter ratio, and the flow rates were varied, with the flow always in the laminar regime. Conductivity measurements, involving tracer impulse response, were used to evaluate the concentrations in three of the tubular vessels six sections. Laguerre polynomial approximation was used to smooth the time dependent concentration related curves. A dependency on the flow conditions in the previous sections was found for all twelve cases studied. Accordingly, the individual residence time distributions were dependent upon each other; hence the individual residence time distributions did not convolute to give an overall residence time distribution and large deviation from plug flow within the tubular vessel existed

Privacy Preserving Internet Browsers: Forensic Analysis of Browzar

With the advance of technology, Criminal Justice agencies are being confronted with an increased need to investigate crimes perpetuated partially or entirely over the Internet. These types of crime are known as cybercrimes. In order to conceal illegal online activity, criminals often use private browsing features or browsers designed to provide total browsing privacy. The use of private browsing is a common challenge faced in for example child exploitation investigations, which usually originate on the Internet. Although private browsing features are not designed specifically for criminal activity, they have become a valuable tool for criminals looking to conceal their online activity. As such, Technological Crime units often focus their forensic analysis on thoroughly examining the web history on a computer. Private browsing features and browsers often require a more in-depth, post mortem analysis. This often requires the use of multiple tools, as well as different forensic approaches to uncover incriminating evidence. This evidence may be required in a court of law, where analysts are often challenged both on their findings and on the tools and approaches used to recover evidence. However, there are very few research on evaluating of private browsing in terms of privacy preserving as well as forensic acquisition and analysis of privacy preserving internet browsers. Therefore in this chapter, we firstly review the private mode of popular internet browsers. Next, we describe the forensic acquisition and analysis of Browzar, a privacy preserving internet browser and compare it with other popular internet browser

Optimizing Neutron Yield for Active Interrogation

Neutrons are commonly used for many applications, including active interrogation and cancer therapy. One critical aspect for active interrogation efficiency is neutron yield, which is more important for successful resolution than the energy spectrum. The typical approach for improving neutron yield entails producing more neutrons, which has motivated multiple studies using the interaction of increasingly more powerful tabletop lasers with plastic targets to generate protons or deuterons that are absorbed by another target to create neutrons [1]. Alternatively, one may use lenses to focus the neutrons to increase yield rather than simply generating more neutrons with more powerful lasers [2]. Assessing either approach requires a comprehensive model simulating neutron generation and transport to optimize the target material, system geometry, and neutron yield. A complete model from laser source to neutron generation is beyond the scope of the current study, so this project focuses on simulating the interaction of deuterons with typical target materials, such as lithium or beryllium. We use the neutron transport code Monte Carlo N-Particles (MCNP), which applies the Monte Carlo method to track particles [3]. The simulations accurately reflected experimental results from several groups [4]. Future analyses will assess improvements in neutron yield and directionality through strategically incorporating neutron lenses