Neuropathology in Alzheimer's disease: awaking from a hundred-year-old dream

For one hundred years after Alois Alzheimer's first report of Alzheimer's disease (AD) in 1906, the pathological hallmarks of the disease, senile plaques and neurofibrillary tangles (NFTs), have been attractive targets for researchers. Therefore, not surprisingly, efforts to understand disease mechanisms have concentrated on the cell biology of amyloid-beta (Abeta) deposition as senile plaques or on the phosphorylation and aggregation of tau as NFTs. However, it now appears that this focus on pathology as a central contributor to disease may be misguided. Indeed, neurons associated with Abeta and NFTs in AD brain show a decrease in oxidative damage relative to those in vulnerable but morphologically intact areas of the brain, suggesting that neurodegenerative lesions are compensatory phenomena, and thus manifestations of cellular adaptation. That Abeta and tau accumulations indicate an age-related physiological reaction to chronic stress calls into question the rationale of current therapeutic efforts targeted toward lesion removal. Moreover, if this concept holds true for pathology in other neurodegenerative diseases, we may need to restructure our thinking and undergo a paradigm shift before substantial progress can be made in therapeutic intervention.     

Identifying the time of change in the mean of a two-stage nested process

Statistical process control charts are used to distinguish between common cause and special cause sources of variability. Once a control chart signals, a search to find the special cause should be initiated. If process analysts had knowledge of the change point, the search to find the special cause could be easily facilitated. Relevant literature contains an array of solutions to the change-point problem; however, these solutions are most appropriate when the samples are assumed to be independent. Unfortunately, the assumption of independence is often violated in practice. This work considers one such case of non-independence that frequently occurs in practice as a result of multi-stage sampling. Due to its commonality in practice, we assume a two-stage nested random model as the underlying process model and derive and evaluate a maximum-likelihood estimator for the change point in the fixed-effects component of this model. The estimator is applied to electron microscopy data obtained following a genuine control chart signal and from a real machining process where the important quality characteristic is the size of the surface grains produced by the machining operation. We conduct a simulation study to compare relative performances between the proposed change-point estimator and a commonly used alternative developed under the assumption of independent observations. The results suggest that both estimators are approximately unbiased; however, the proposed estimator yields smaller variance. The implication is that the proposed estimator is more precise, and thus, the quality of the estimator is improved relative to the alternative.     

Empowered Learners: The New Paradigm for 2000 and Beyond

In the fast-growing new technology-based industrial landscape in the UnitedStates, companies have had to face a major problem. Many job applicants havehad such a poor educational preparation that many companies are required tooffer remedial courses in the basic subjects to ensure employee readiness forsuch positions. Many times, however, the educational approach taken bycompanies is very similar to that which was taken by the schools which havefailed these employees – the typical `chalk and talk' approach. Thisarticle suggests an alternative approach to employee education. Thisresearch-based theory states each individual learns in a unique way which canbe diagnosed and utilized to ensure maximum educational effectiveness. Thisapproach has already been employed in a high school setting, and the resultssupport this approach. The theory is not predicated on school-age studentsalone, hence a transition to the workforce is entirely credible, to thebenefit of companies and individuals alike.     

An acarine predator-prey population infesting roses

Summary WhenPhytoseiulus persimilis was reared withTetranychus urticae, infesting roses propagated in a greenhouse at controlled daily temperatures of 24°C (12 hrs) and 18°C (12 hrs), prey numbers fluctuated with peaks of increasing amplitude. Differential dispersal of prey and predator species was one factor contributing to the inability of the natural enemy to control the pest population.     

‘Keeping it real’: tryhards,clones and youth discourses of authentic identity from Hollywood to high school

Authenticity is a key cultural rubric for youth in the contemporary West. Texts aimed at young people frequently direct viewers to ‘keep it real’, to ‘be themselves’ and to avoid ‘putting up a front’. ‘Being yourself’ is portrayed as a moral achievement, yet also as something subjects should ‘naturally’ be. This article examines how students at an urban high school in Aotearoa/New Zealand conceive of being ‘real’, exploring what they deem to be authentic identity and its expressions. This article considers the students' use of both constructionist ‘surface’ and essentialist ‘depth’ discourses of identity. It examines how the students conceive of authentic identity as both stable and fluid, anchored in bodily experience and produced at the moment of recognition by others. It argues that through the production of the figures of the ‘clone’ and the ‘tryhard’, the students resolve the tension created by their positioning of identity as inseparable from the gaze of others and their view that to live for others is inauthentic. The students distance themselves from the behaviour of these Others, who they conceive as presenting themselves inauthentically. The students' conceptualisation of authenticity and use of the figures of the clone and the tryhard provides impetus for the positioning of authentic identity as performative, produced through its enactment.     

College students' perceptions of risk and addictiveness of e-cigarettes and cigarettes

Background: As conventional cigarette use is declining, electronic cigarette (“e-cigarette”) use is rising and is especially high among college students. Few studies examine dual use of e-cigarettes and cigarettes among this population. This study explores the relationship between dual and exclusive e-cigarette / cigarette use and perceptions of harm and addictiveness of both products. Methods: This is a cross-sectional analysis of data from students attending 24 colleges in Texas (n=5,482). Multinomial logistic regression was employed to test the association between current e-cigarette / cigarette use and perceived harm and addictiveness of both products. Three tobacco groups were included: cigarette only users, e-cigarette only users, and dual users. Results: Dual users reported lower perceived harm of e-cigarettes most consistently (p<0.001, all comparisons). Perceived harm of cigarettes was significantly lower among cigarette only and dual users only, compared to non-users (p<0.001, all comparisons). Compared to non-users, all three groups reported significantly lower perceived addictiveness of e-cigarettes (p<0.001, all comparisons). The same finding was observed for perceived addictiveness of cigarettes, though findings were less consistent for the e-cigarette only group (p<0.02, all comparisons except one). Conclusion: Findings demonstrate that among college students, perceptions of harm and addictiveness of e-cigarettes are lower than those for conventional cigarettes. For both products, perceptions of harm and addictiveness were lower among exclusive and dual users, compared to non-users.     

Till Porn Do Us Part? A Longitudinal Examination of Pornography Use and Divorce

As pornography use becomes more commonplace in the United States, and increasingly so among younger cohorts, a growing literature is considering its potential connection to key social and cultural institutions. The current study examined the relationship between pornography use and one such institution: marriage. We drew on three-wave longitudinal data from 2006 to 2014 General Social Survey panel studies to determine whether married Americans’ pornography use predicted their likelihood of divorce over time and under what social conditions. We employed a doubly robust strategy that combines entropy balancing with logistic regression models. We found that the probability of divorce roughly doubled for married Americans who began pornography use between survey waves (N = 2,120; odds ratio = 2.19), and that this relationship held for both women and men. Conversely, discontinuing pornography use between survey waves was associated with a lower probability of divorce, but only for women. Additional analyses also showed that the association between beginning pornography use and the probability of divorce was particularly strong among younger Americans, those who were less religious, and those who reported greater initial marital happiness. We conclude by discussing data limitations, considering potential intervening mechanisms and the possibility of reverse causation, and outlining implications for future research.     

Estimating Quality of Life and Place with Location Theory: The McBucks Index

This paper explores the changes in inequality and welfare between EU regions at the NUTS 3 level over the 2003–2011 period. Changes in absolute and relative inequalities are broken down into components explaining the effects of population change, re-ranking of regions and income growth between regional per capita incomes. Each component of inequality change is further decomposed by subgroup, revealing the contributions arising from changes within subgroups and from changes between subgroups. The decomposition of the change in absolute inequality is used to develop a decomposition of the change in welfare between EU regions.