Newcastle University

About: Newcastle University is a education organization based out in Newcastle upon Tyne, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 31772 authors who have published 71187 publications receiving 2539147 citations. The organization is also known as: University of Newcastle upon Tyne.

Vascular dysfunction-The disregarded partner of Alzheimer's disease

Abstract: Increasing evidence recognizes Alzheimer's disease (AD) as a multifactorial and heterogeneous disease with multiple contributors to its pathophysiology, including vascular dysfunction. The recently updated AD Research Framework put forth by the National Institute on Aging-Alzheimer's Association describes a biomarker-based pathologic definition of AD focused on amyloid, tau, and neuronal injury. In response to this article, here we first discussed evidence that vascular dysfunction is an important early event in AD pathophysiology. Next, we examined various imaging sequences that could be easily implemented to evaluate different types of vascular dysfunction associated with, and/or contributing to, AD pathophysiology, including changes in blood-brain barrier integrity and cerebral blood flow. Vascular imaging biomarkers of small vessel disease of the brain, which is responsible for >50% of dementia worldwide, including AD, are already established, well characterized, and easy to recognize. We suggest that these vascular biomarkers should be incorporated into the AD Research Framework to gain a better understanding of AD pathophysiology and aid in treatment efforts.

A low-cost attack on a Microsoft captcha

Abstract: CAPTCHA is now almost a standard security technology. The most widely deployed CAPTCHAs are text-based schemes, which typically require users to solve a text recognition task. The state of the art of CAPTCHA design suggests that such text-based schemes should rely on segmentation resistance to provide security guarantee, as individual character recognition after segmentation can be solved with a high success rate by standard methods such as neural networks.In this paper, we present new character segmentation techniques of general value to attack a number of text CAPTCHAs, including the schemes designed and deployed by Microsoft, Yahoo and Google. In particular, the Microsoft CAPTCHA has been deployed since 2002 at many of their online services including Hotmail, MSN and Windows Live. Designed to be segmentation-resistant, this scheme has been studied and tuned by its designers over the years. However, our simple attack has achieved a segmentation success rate of higher than 90% against this scheme. It took on average ~80 ms for the attack to completely segment a challenge on an ordinary desktop computer. As a result, we estimate that this CAPTCHA could be instantly broken by a malicious bot with an overall (segmentation and then recognition) success rate of more than 60%. On the contrary, the design goal was that automated attacks should not achieve a success rate of higher than 0.01%. For the first time, this paper shows that CAPTCHAs that are carefully designed to be segmentation-resistant are vulnerable to novel but simple attacks.

Gene expression across mammalian organ development

Abstract: The evolution of gene expression in mammalian organ development remains largely uncharacterized. Here we report the transcriptomes of seven organs (cerebrum, cerebellum, heart, kidney, liver, ovary and testis) across developmental time points from early organogenesis to adulthood for human, rhesus macaque, mouse, rat, rabbit, opossum and chicken. Comparisons of gene expression patterns identified correspondences of developmental stages across species, and differences in the timing of key events during the development of the gonads. We found that the breadth of gene expression and the extent of purifying selection gradually decrease during development, whereas the amount of positive selection and expression of new genes increase. We identified differences in the temporal trajectories of expression of individual genes across species, with brain tissues showing the smallest percentage of trajectory changes, and the liver and testis showing the largest. Our work provides a resource of developmental transcriptomes of seven organs across seven species, and comparative analyses that characterize the development and evolution of mammalian organs.

Using QSR‐NVivo to facilitate the development of a grounded theory project: an account of a worked example

Abstract: This paper demonstrates how the software package QSR‐NVivo can be used to faciitate a grounded theory approach. Recent research evidence has questioned the methodological quality of many studies that claim to utilise grounded theory. This paper argues that qualitative data analysis software can be used to encourage good quality grounded theory research by facilitating many of the key processes and characteristics associated with this approach. To achieve this, the paper identifies a number of grounded theory characteristics, common to all revisions of the methodology. It then describes the development of a recent study, which examined how people successfully maintain long‐term physical activity behaviour change. The purpose of this is to demonstrate how different functions of QSR‐NVivo may be used in conjunction with the key grounded theory characteristics. In summary, QSR‐NVivo is a powerful tool that, if used appropriately, can facilitate many aspects of the grounded theory process from the design and e...

Instabilities in polymer processing

Abstract: Instabilities which arise in shear and extensional flows in the processing of polymeric liquids are reviewed. The experimental observations and the extent of theoretical understanding of the instabilities are discussed.