Stochastic simulation for spatial modelling of dynamic process in a living cell

One of the fundamental motivations underlying computational cell biology is to gain insight into the complicated dynamical processes taking place, for example, on the plasma membrane or in the cytosol of a cell. These processes are often so complicated that purely temporal mathematical models cannot adequately capture the complex chemical kinetics and transport processes of, for example, proteins or vesicles. On the other hand, spatial models such as Monte Carlo approaches can have very large computational overheads. This chapter gives an overview of the state of the art in the development of stochastic simulation techniques for the spatial modelling of dynamic processes in a living cell.

Computing with motile bio-agents

We describe a model of computation of the parallel type, which we call 'computing with bio-agents', based on the concept that motions of biological objects such as bacteria or protein molecular motors in confined spaces can be regarded as computations. We begin with the observation that the geometric nature of the physical structures in which model biological objects move modulates the motions of the latter. Consequently, by changing the geometry, one can control the characteristic trajectories of the objects; on the basis of this, we argue that such systems are computing devices. We investigate the computing power of mobile bio-agent systems and show that they are computationally universal in the sense that they are capable of computing any Boolean function in parallel. We argue also that using appropriate conditions, bio-agent systems can solve NP-complete problems in probabilistic polynomial time.

A software tool for simulating spatial separation and kinetics in biological membranes

Self-segregation and compartimentalisation are observed experimentally to occur spontaneously on live membranes as well as reconstructed model membranes. It is believed that many of these processes are caused or supported by anomalous diffusive behaviours of biomolecules on membranes due to the complex and heterogeneous nature of these environments. These phenomena are on the one hand of great interest in biology, since they may be an important way for biological systems to selectively localize receptors, regulate signaling or modulate kinetics; and on the other, they provide an inspiration for engineering designs that mimick natural systems. We present an interactive software package we are developing for the purpose of simulating such processes numerically using a fundamental Monte Carlo approach. This program includes the ability to simulate kinetics and mass transport in the presence of either mobile or immobile obstacles and other relevant structures such as liquid-ordered lipid microdomains. We also present preliminary simulation results regarding the selective spatial localization and chemical kinetics modulating power of immobile obstacles on the membrane, obtained using the program.

Psychological interventions for alcohol misuse among people with co-occurring depression or anxiety disorders: A systematic review

Abstract OBJECTIVE: Depression, anxiety and alcohol misuse frequently co-occur. While there is an extensive literature reporting on the efficacy of psychological treatments that target depression, anxiety or alcohol misuse separately, less research has examined treatments that address these disorders when they co-occur. We conducted a systematic review to determine whether psychological interventions that target alcohol misuse among people with co-occurring depressive or anxiety disorders are effective. DATA SOURCES: We systematically searched the PubMed and PsychINFO databases from inception to March 2010. Individual searches in alcohol, depression and anxiety were conducted, and were limited to 'human' published 'randomized controlled trials' or 'sequential allocation' articles written in English. STUDY SELECTION: We identified randomized controlled trials that compared manual guided psychological interventions for alcohol misuse among individuals with depressive or anxiety disorders. Of 1540 articles identified, eight met inclusion criteria for the review. DATA EXTRACTION: From each study, we recorded alcohol and mental health outcomes, and other relevant clinical factors including age, gender ratio, follow-up length and drop-out rates. Quality of studies was also assessed. DATA SYNTHESIS: Motivational interviewing and cognitive-behavioral interventions were associated with significant reductions in alcohol consumption and depressive and/or anxiety symptoms. Although brief interventions were associated with significant improvements in both mental health and alcohol use variables, longer interventions produced even better outcomes. CONCLUSIONS: There is accumulating evidence for the effectiveness of motivational interviewing and cognitive behavior therapy for people with co-occurring alcohol and depressive or anxiety disorders.

YouTube and the formalisation of amateur media

This chapter describes how, as YouTube has scaled up both as a platform and as a company, its business model and the consequences for its copyright regulation strategies have co-evolved, and so too the boundaries between amateur and professional media have shifted and blurred in particular ways. As YouTube, Inc moves to more profitably arrange and stabilise the historically contentious relations among rights-holders, uploaders, advertisers and audiences, some forms of amateur video production have become institutionalised and professionalised, while others have been further marginalised and driven underground or to other, more forgiving, platforms.

Discovering the best feature extraction and selection algorithms for spontaneous facial expression recognition

Feature extraction and selection are critical processes in developing facial expression recognition (FER) systems. While many algorithms have been proposed for these processes, direct comparison between texture, geometry and their fusion, as well as between multiple selection algorithms has not been found for spontaneous FER. This paper addresses this issue by proposing a unified framework for a comparative study on the widely used texture (LBP, Gabor and SIFT) and geometric (FAP) features, using Adaboost, mRMR and SVM feature selection algorithms. Our experiments on the Feedtum and NVIE databases demonstrate the benefits of fusing geometric and texture features, where SIFT+FAP shows the best performance, while mRMR outperforms Adaboost and SVM. In terms of computational time, LBP and Gabor perform better than SIFT. The optimal combination of SIFT+FAP+mRMR also exhibits a state-of-the-art performance.

Preparing general technology teachers in China for new roles and responsibilities

This paper discusses the conceptualization, implementation and initial findings of a professional learning program (PLP) which used LEGO® robotics as one of the tools for teaching general technology (GT)in China’s secondary schools. The program encouraged teachers to design learning environments that can be realistic, authentic, engaging and fun. 100 general technology teachers from high schools in 30 provinces of China participated. The program aimed to transform teacher classroom practice, change their beliefs and attitudes, allow teachers to reflect deeply on what they do and in turn to provide their students with meaningful learning. Preliminary findings indicate that these teachers had a huge capacity for change. They were open-minded and absorbed new ways of learning and teaching. They became designers who developed innovative models of learning which incorporated learning processes that effectively used LEGO® robotics as one of the more creative tools for teaching GT.

Confrontation and cooptation : a brief history of Australian political blogs

The history of political blogging in Australia does not entirely match the development of blogospheres in other countries. Even at its beginning, blogging was not an entirely alternative endeavour – one of the first news or political blogs was Margo Kingston’s Webdiary, hosted by the Sydney Morning Herald. In the United States, whose political blogosphere has been examined most comprehensively in the literature (see e.g. Adamic & Glance, 2005; Drezner & Farrell, 2008; Shaw & Benkler, 2012; Tremayne, 2007; Wallsten, 2008), blogging had a clear historical trajectory from alternative to mainstream medium. The Australian blogosphere, by contrast, has seen early and continued involvement from representatives of the mainstream media, blogging both for their employers and independently (Garden, 2010). Coupled with the incorporation of blog-like technologies into news websites, as well as with obvious differences in the size of the available talent pool and potential audience for political blogging in Australia, this recognition of blogging by the mainstream media may be one reason why, in political and news discussions at least, Australian bloggers did not bring about their own, local equivalents to the resignations of Dan Rather or Trent Lott in the U.S. –events which were commonly attributed in part to the work of bloggers (Simons, 2007). However, the acceptance of the blogging concept by the mainstream media has been accompanied by a comparative lack of acceptance towards individual bloggers. Analyses and commentary published by bloggers have been attacked by journalists, creating an at times antagonistic relationship between the mainstream media and bloggers (Flew & Wilson, 2010; Young, 2011). In this article, we examine the historical development of blogging in Australia, focussing primarily on political and news blogs. In particular, we review who the bloggers are and how the connections between different blogs and other titles have changed over the past decade. The paper tracks the evolution of individual and group blogs, independent and mainstream media-hosted opinion sites, and the gradual convergence of these platforms and their associated contributing authors. We conclude by examining the current state of the Australian blogosphere and its likely future development, taking into account the rise of social media, and in particular Twitter, as additional spaces for public commentary.

Impact of region-of-interest video coding on perceived quality in mobile video

Effective streaming of video can be achieved by providing more bits to the most important region in the frame at the cost of reduced bits in the less important regions. This strategy can be beneficial for delivering high quality videos in mobile devices, especially when the availability of bandwidth is usually low and limited. While the state-of-the-art video codecs such as H.264 may have been optimised for perceived quality, it is hypothesised that users will give more attention to interesting region/object when watching videos. Therefore, giving a higher quality to region of interest (ROI)while reducing quality of other areas may result in improving the overall perceived quality without necessarily increasing the bitrate. In this paper, the impact of ROI-based encoded video on perceived quality is investigated by conducting a user study for varous target bitrates. The results from the user study demonstrate that ROI-based video coding has superior perceived quality compared to normal encoded video at the same bitrate in the lower bitrate range.