Purdue Libraries in Second Life

Poster was presented at the Purdue Libraries One Book Higher Poster Session. Focus is on the activities and experimentation within the virtual world Second Life by the Purdue Libraries. Key projects were the virtual presentation of Amelia Earhart photographs and a simulation in a restaurant setting for hospitality & tourism management research

Degradation of Polymers Based on Styrene and Butadiene

This discussion is concerned with the preparation, characterisation and subsequent degradation of some high polymers based on styrene and butadiene. It also considers some refinements to existing high vacuum techniques of thermal analysis and in addition, the development of a set of techniques able to identify and manipulate quantitatively the noncondensable product fraction associated with thermal degradation under open pumping conditions of polymer systems

Resolving the enigma of the clonal expansion of mtDNA deletions

Mitochondria are cell organelles that are special since they contain their own genetic material in the form of mitochondrial DNA (mtDNA). Damage and mutations of mtDNA are not only involved in several inherited human diseases but are also widely thought to play an important role during aging. In both cases, point mutations or large deletions accumulate inside cells, leading to functional impairment once a certain threshold has been surpassed. In most cases, it is a single type of mutant that clonally expands and out-competes the wild type mtDNA, with different mutant molecules being amplified in different cells. The challenge is to explain where the selection advantage for the accumulation comes from, why such a large range of different deletions seem to possess this advantage, and how this process can scale to species with different lifespans such as those of rats and man. From this perspective, we provide an overview of current ideas, present an update of our own proposal, and discuss the wider relevance of the phenomenon for aging

Inactivation of presenilins causes pre-synaptic impairment prior to post-synaptic dysfunction

Synaptic dysfunction is widely thought to be a pathogenic precursor to neurodegeneration in Alzheimer’s disease (AD), and the extent of synaptic loss provides the best correlate for the severity of dementia in AD patients. Presenilins 1 and 2 are the major causative genes of early‐onset familial AD. Conditional inactivation of presenilins in the adult cerebral cortex results in synaptic dysfunction and memory impairment, followed by age‐dependent neurodegeneration. To characterize further the consequence of presenilin inactivation in the synapse, we evaluated the temporal development of pre‐synaptic and post‐synaptic deficits in the Schaeffer‐collateral pathway of presenilin conditional double knockout (PS cDKO) mice prior to onset of neurodegeneration. Following presenilin inactivation at 4 weeks, synaptic facilitation and probability of neurotransmitter release are impaired in PS cDKO mice at 5 weeks of age, whereas post‐synaptic NMDA receptor (NMDAR)‐mediated responses are normal at 5 weeks but impaired at 6 weeks of age. Long‐term potentiation induced by theta burst stimulation is also reduced in PS cDKO mice at 6 weeks of age. These results show that loss of presenilins results in pre‐synaptic deficits in short‐term plasticity and probability of neurotransmitter release prior to post‐synaptic NMDAR dysfunction, raising the possibility that presenilins may regulate post‐synaptic NMDAR function in part via a trans‐synaptic mechanism.This work was supported by the National Institute of Health NS041783 (to J.S.). We would like to thank Xiaoyan Zou and Huailong Zhao for technical assistance. (NS041783 - National Institute of Health)Published versio

The Counterfeit Conundrum: A Case Study to Examine the Best Way to Combat Counterfeit Consumption

Estimated at more than $500 billion, counterfeits are a booming industry. The negative impacts can no longer be ignored. As evidenced by the industry growth, efforts to combat consumption of counterfeit products have largely failed. This case study examines the counterfeit industry and a campaign developed by the U.S. Customs and Border Protection Agency. It presents the reader the opportunity to contemplate viable solutions for ending counterfeit consumption