Community detection and role identification in directed networks: understanding the Twitter network of the care.data debate

With the rise of social media as an important channel for the debate and discussion of public affairs, online social networks such as Twitter have become important platforms for public information and engagement by policy makers. To communicate effectively through Twitter, policy makers need to understand how influence and interest propagate within its network of users. In this chapter we use graph-theoretic methods to analyse the Twitter debate surrounding NHS Englands controversial care.data scheme. Directionality is a crucial feature of the Twitter social graph - information flows from the followed to the followers - but is often ignored in social network analyses; our methods are based on the behaviour of dynamic processes on the network and can be applied naturally to directed networks. We uncover robust communities of users and show that these communities reflect how information flows through the Twitter network. We are also able to classify users by their differing roles in directing the flow of information through the network. Our methods and results will be useful to policy makers who would like to use Twitter effectively as a communication medium

Almost reducibility for finitely differentiable SL(2,R)-valued quasi-periodic cocycles

Quasi-periodic cocycles with a diophantine frequency and with values in SL(2,R) are shown to be almost reducible as long as they are close enough to a constant, in the topology of k times differentiable functions, with k great enough. Almost reducibility is obtained by analytic approximation after a loss of differentiability which only depends on the frequency and on the constant part. As in the analytic case, if their fibered rotation number is diophantine or rational with respect to the frequency, such cocycles are in fact reducible. This extends Eliasson's theorem on Schr\"odinger cocycles to the differentiable case

Portable and efficient FFT and DCT algorithms with the Heterogeneous Butterfly Processing Library

Versión final aceptada de: https://doi.org/10.1016/j.jpdc.2018.11.011This version of the article: Vázquez, S., Amor, M., Fraguela, B. B. (2019). 'Portable and efficient FFT and DCT algorithms with the heterogeneous butterfly processing library', has been accepted for publication in Journal of Parallel and Distributed Computing, 125, 135–146. The Version of Record is available online at https://doi.org/10.1016/j.jpdc.2018.11.011.[Abstract]: The existence of a wide variety of computing devices with very different properties makes essential the development of software that is not only portable among them, but which also adapts to the properties of each platform. In this paper, we present the Heterogeneous Butterfly Processing Library (HBPL), which provides optimized portable kernels for problems of small sizes that allow using orthogonal transform algorithms such as the FFT and DCT on different accelerators and regular CPUs. Our library is implemented on the OpenCL standard, which provides portability on a large number of platforms. Furthermore, high performance is achieved on a wide range of devices by exploiting run-time code generation and metaprogramming guided by a parametrization strategy. An exhaustive evaluation on different platforms shows that our proposal obtains competitive or better performance than related libraries.This research has received financial support from the Ministerio de Economía y Competitividad of Spain and European Regional Development Fund (ERDF) funds (80%) of the EU (TIN2016-75845-P), by the Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia co-founded by European Regional Development Fund (ERDF) funds under the Consolidation Programme of Competitive Reference Groups (Ref. ED431C 2017/04) and the Consolidation Programme of Competitive Research Units (Ref. R2014/049 and Ref. R2016/037) as well as by the Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia (Centro Singular de Investigación de Galicia accreditation 2016–2019) and the European Union (European Regional Development Fund, ERDF) under Grant Ref. ED431G/01.Xunta de Galicia; ED431C 2017/04Xunta de Galicia; ED431G/01Xunta de Galicia; R2014/049Xunta de Galicia; R2016/03

Uncovering allosteric pathways in caspase-1 with Markov transient analysis and multiscale community detection

Allosteric regulation at distant sites is central to many cellular processes. In particular, allosteric sites in proteins are a major target to increase the range and selectivity of new drugs, and there is a need for methods capable of identifying intra-molecular signalling pathways leading to allosteric effects. Here, we use an atomistic graph-theoretical approach that exploits Markov transients to extract such pathways and exemplify our results in an important allosteric protein, caspase-1. Firstly, we use Markov Stability community detection to perform a multiscale analysis of the structure of caspase-1 which reveals that the active conformation has a weaker, less compartmentalised large-scale structure as compared to the inactive conformation, resulting in greater intra-protein coherence and signal propagation. We also carry out a full computational point mutagenesis and identify that only a few residues are critical to such structural coherence. Secondly, we characterise explicitly the transients of random walks originating at the active site and predict the location of a known allosteric site in this protein quantifying the contribution of individual bonds to the communication pathway between the active and allosteric sites. Several of the bonds we find have been shown experimentally to be functionally critical, but we also predict a number of as yet unidentified bonds which may contribute to the pathway. Our approach offers a computationally inexpensive method for the identification of allosteric sites and communication pathways in proteins using a fully atomistic description.Comment: 14 pages, 8 figure

The membrane bound N-terminal domain of human adenosine diphosphate ribosylation factor-1 (ARF1)

The small G protein adenosine diphosphate ribosylation factor-1 (ARF1) is activated by cell membrane binding of a self-folding N-terminal domain. We present a model of the human ARF1 N-terminal peptide in planar lipid bilayers, determined from neutron lamellar diffraction and circular dichroism data with molecular modelling. This amphipathic domain lies at a shallow membrane depth, ideal for regulation of the ARF1 bio-timer by rapid, reversible membrane binding. The helical region does not elongate upon membrane binding, leaving the connecting flexible linker region's length unchanged.NRC publication: N

Improving the Academic Performance and Motivation of Grade 10 Students in Music Using Interactive Portable Module (IPM)

This study focused on determining the effectiveness of the utilization of Interactive Portable Module (IPM) in the teaching and learning process of Music concepts that aims to improve the academic performance as well as the level of motivation of the students. The participants of the study were from the Grade 10 junior high school students of Silae National High School who were officially enrolled in the School Year 2022-2023. The students were heterogeneous in composition and since the population of Grade 10 curriculum was only 56, all of them were chosen as the participants of the study. In this study, pre- experimental research design was used because it only involves a single group using non-probability sampling specifically total population sampling. Results in researchers made pre-test and post-test of music lessons serves as the academic performance of the students were compared and the outcome of the assessment in motivation level of the students was also analysed. The researchers made academic performance test had resulting Cronbach alpha value was 0.781 which means that the test items were good and adopted with modification a motivational survey questionnaire from Glynn & Koballa, 2006 with the Cronbach alpha value of 0.91.The mean scores of the students in pre-test and post-test increases and had a significant difference on the academic performance before and after the intervention of interactive portable modules (IPM) therefore the alternative hypothesis was accepted. It signifies that the applied intervention was effective enough in improving the academic performance of the students. The students also developed their motivation level into highly motivated wherein the students are much more interested and active in learning music concepts since the students motivation is highly associated with their academic performance

Assessing the climate change impacts of biogenic carbon in buildings: a critical review of two main dynamic approaches

Wood is increasingly perceived as a renewable, sustainable building material. The carbon it contains, biogenic carbon, comes from biological processes; it is characterized by a rapid turnover in the global carbon cycle. Increasing the use of harvested wood products (HWP) from sustainable forest management could provide highly needed mitigation efforts and carbon removals. However, the combined climate change benefits of sequestering biogenic carbon, storing it in harvested wood products and substituting more emission-intensive materials are hard to quantify. Although different methodological choices and assumptions can lead to opposite conclusions, there is no consensus on the assessment of biogenic carbon in life cycle assessment (LCA). Since LCA is increasingly relied upon for decision and policy making, incorrect biogenic carbon assessment could lead to inefficient or counterproductive strategies, as well as missed opportunities. This article presents a critical review of biogenic carbon impact assessment methods, it compares two main approaches to include time considerations in LCA, and suggests one that seems better suited to assess the impacts of biogenic carbon in buildings

Latent space policy search for robotics

Learning motor skills for robots is a hard task. In particular, a high number of degrees-of-freedom in the robot can pose serious challenges to existing reinforcement learning methods, since it leads to a highdimensional search space. However, complex robots are often intrinsically redundant systems and, therefore, can be controlled using a latent manifold of much smaller dimensionality. In this paper, we present a novel policy search method that performs efficient reinforcement learning by uncovering the low-dimensional latent space of actuator redundancies. In contrast to previous attempts at combining reinforcement learning and dimensionality reduction, our approach does not perform dimensionality reduction as a preprocessing step but naturally combines it with policy search. Our evaluations show that the new approach outperforms existing algorithms for learning motor skills with high-dimensional robots

Performance of LED fluorescence microscopy for the detection of tuberculosis in Rwanda using Zeiss Primo Star

Introduction: Ziehl-Neelsen (ZN) bright-field microscopy is time-consuming, with poor sensitivity, even under optimal conditions. Introduction of Primo Star iLED fluorescent microscopy (FM) may improve TB case finding at referral hospitals in Rwanda. The study aimed to determine the acceptability and effectiveness of iLED in a low resource setting. Methods: Between June 2009 and May 2010, the Rwandan TB Program and National Reference Laboratory carried out demonstration studies with iLED at a referral hospital in the capital, Kigali, and a rural district hospital in Nyamata, taking conventional FM as Gold Standard. Results: Agreement between the iLED and rechecking at the Reference Laboratory were deemed “almost perfect” (kappa = 0.81-1.00) across three of four site-phase combinations. The exception was Nyamata District Hospital during the validation phase, which was deemed “substantial” agreement (kappa = 0.61-0.80). However, the 100% concordance at both demonstration sites during the continuation phase shows technicians' rapid command of the new iLED microscope in a relatively short time. The lower overall positivity rate obtained in the rural clinic is not related to the performance of the microscope (or technicians), but is attributable to a significant increase in total number of patients and samples screened through active case finding. Conclusion: Laboratory technicians demonstrated high acceptance of iLED. Additionally, fluorescent microscopy reduces the time necessary for examination by more than half. The high level of agreement between iLED and FM during implementation in both sites provides initial evidence for iLED to replace current methods