Tensile and shear strength of adhesives

This experiment is conducted in a freshman-level course: Introduction to Engineering Materials. There are no prerequisites for the course although students should have some knowledge of basic algebra. The objectives are to tension and shear test adhesives and to determine the tensile and shear properties of adhesives. Details of equipment of procedure are given

Economic aspects of spectrum management

Problems associated with the allocation of the radio frequency spectrum are addressed. It is observed that the current method very likely does not allocate the resource to those most valuing its use. Ecomonic criteria by which the effectiveness of resource allocation schemes can be judged are set forth and some thoughts on traditional objections to implementation of market characteristics into frequency allocation are offered. The problem of dividing orbit and spectrum between two satellite services sharing the same band but having significantly different system characteristics is discussed. The problem is compounded by the likelihood that one service will commence operation much sooner than the other. Some alternative schemes are offered that, within proper international constraints, could achieve a desired flexibility in the division of orbit and frequency between the two services domestically over the next several years

The role of beige fat in combating obesity

As obesity and obesity-associated diseases become more prevalent in western societies, new methods to promote weight-loss and protect patients from the dangerous consequences of excess adipose tissue are needed. While both researchers and clinicians previously turned to chemical uncouplers for many decades to create a negative energy balance and thus promote weight-loss, these compounds proved to be extremely dangerous treatment options, even when taken in mild dosages. Substances like 2-4 dinitrophenol (DNP), were able to significantly induce weight loss, however many life-threatening conditions such as fatal hyperthermia are commonly attributed to these uncoupling agents. Recently, with the discovery of natural brown/beige fat reservoirs in humans, many members of the medical community have become heavily invested in the targeting of more localized, less systemic uncoupling tissues. The action of UCP-1 in human thermogenic adipose introduces an opportunity to harness a natural, yet futile cycle, and hence boost a patient’s basal metabolism without ultimately compromising their long-term health. Many challenges remain before such a treatment is viable, including deciphering the biochemical pathways that induce brown fat thermogenesis. It appears that several uncoupling signals may govern the genetic programs that lead to this thermogenic activity, and the "browning" of white adipose stores in humans. Particularly in the last ten years, many studies have uncovered new components of the thermogenic program by ablating target genes in mice. While a direct pathway of thermogenic activation does exist when subjects are placed in a cold environment, a successful, high-adoption, anti-obesity treatment through a thermogenic regimen will likely involve a gene-therapy or protein-based biopharmaceutical intervention. It is conceivable that thermogenic manipulation could play a significant role in the battle against obesity and obesity-associated diseases, however a significant intellectual breakthrough in appetite suppression and/or appetite management (i.e. a successful intervention of the orexigenic and anorexigenic physiological pathways) could in theory supplant this approach

Epithelial-mesenchymal plasticity determines estrogen receptor positive breast cancer dormancy and epithelial reconversion drives recurrence

More than 70% of human breast cancers (BCs) are estrogen receptor α-positive (ER+). A clinical challenge of ER+ BC is that they can recur decades after initial treatments. Mechanisms governing latent disease remain elusive due to lack of adequate in vivo models. We compare intraductal xenografts of ER+ and triple-negative (TN) BC cells and demonstrate that disseminated TNBC cells proliferate similarly as TNBC cells at the primary site whereas disseminated ER+ BC cells proliferate slower, they decrease CDH1 and increase ZEB1,2 expressions, and exhibit characteristics of epithelial-mesenchymal plasticity (EMP) and dormancy. Forced E-cadherin expression overcomes ER+ BC dormancy. Cytokine signalings are enriched in more active versus inactive disseminated tumour cells, suggesting microenvironmental triggers for awakening. We conclude that intraductal xenografts model ER + BC dormancy and reveal that EMP is essential for the generation of a dormant cell state and that targeting exit from EMP has therapeutic potential