How do consumers react in front of individual and combined sustainable food labels? A UK focus group study

A lot of sustainable food labels are now available. They may be complementary or add to the increasing competition of product information in consumers' minds. This paper investigates (1) two focus groups consumers' perceptions about sustainable labels versus other labels, such as origin or nutrition labels, and (2) consumers' reactions to combinations of different sustainable claims or labels. Overall, findings indicate that there is interest in combining different claims into a single label. However, the results also indicate the importance of familiarity, trust and, fit between combinations of labels as well as between a label associated with a brand. While the combination of certain labels can enhance the value of a food product, this study also indicates that other label combinations can detract from a label's value. ...French Abstract : De nombreux produits alimentaires avec des labels "durables" sont proposés aujourd'hui aux consommateurs. Ils peuvent être complémentaires ou à l'opposé augmenter la concurrence entre les différents éléments d'information dans l'esprit des consommateurs. Cet article étudie les perceptions qu'ont des consommateurs interrogés lors de deux focus groups au Royaume-Uni, des labels durables par comparaison à d'autres labels (nutrition ou origine), et leur réaction à des combinaisons de messages et de labels durables. De façon générale, les résultats indiquent qu'il est utile de combiner plusieurs messages sur un même label. Cependant l'étude montre aussi l'importance de la familiarité, de la confiance, de la cohérence perçue entre labels ou entre un label et une marque associée. Certaines combinaisons peuvent en effet faire perdre de la valeur à un label durable au lieu de lui en donner.SUSTAINABLE FOOD; LABELS; QUALITATIVE STUDY; TRUST; FIT

Objective quantification of nanoscale protein distributions

Nanoscale distribution of molecules within small subcellular compartments of neurons critically influences their functional roles. Although, numerous ways of analyzing the spatial arrangement of proteins have been described, a thorough comparison of their effectiveness is missing. Here we present an open source software, GoldExt, with a plethora of measures for quantification of the nanoscale distribution of proteins in subcellular compartments (e.g. synapses) of nerve cells. First, we compared the ability of five different measures to distinguish artificial uniform and clustered patterns from random point patterns. Then, the performance of a set of clustering algorithms was evaluated on simulated datasets with predefined number of clusters. Finally, we applied the best performing methods to experimental data, and analyzed the nanoscale distribution of different pre- and postsynaptic proteins, revealing random, uniform and clustered sub-synaptic distribution patterns. Our results reveal that application of a single measure is sufficient to distinguish between different distributions

Long memory estimation for complex-valued time series

Long memory has been observed for time series across a multitude of fields and the accurate estimation of such dependence, e.g. via the Hurst exponent, is crucial for the modelling and prediction of many dynamic systems of interest. Many physical processes (such as wind data), are more naturally expressed as a complex-valued time series to represent magnitude and phase information (wind speed and direction). With data collection ubiquitously unreliable, irregular sampling or missingness is also commonplace and can cause bias in a range of analysis tasks, including Hurst estimation. This article proposes a new Hurst exponent estimation technique for complex-valued persistent data sampled with potential irregularity. Our approach is justified through establishing attractive theoretical properties of a new complex-valued wavelet lifting transform, also introduced in this paper. We demonstrate the accuracy of the proposed estimation method through simulations across a range of sampling scenarios and complex- and real-valued persistent processes. For wind data, our method highlights that inclusion of the intrinsic correlations between the real and imaginary data, inherent in our complex-valued approach, can produce different persistence estimates than when using real-valued analysis. Such analysis could then support alternative modelling or policy decisions compared with conclusions based on real-valued estimation

Statistical Frameworks for Detecting Tunnelling in Cyber Defence Using Big Data

Abstract—How can we effectively use costly statistical models in the defence of large computer networks? Statistical modelling and machine learning are potentially powerful ways to detect threats as they do not require a human level understanding of the attack. However, they are rarely applied in practice as the computational cost of deploying all but the most simple algorithms can become implausibly large. Here we describe a multilevel approach to statistical modelling in which descriptions of the normal running of the network are built up from the lower netflow level to higher-level sessions and graph-level descriptions. Statistical models at low levels are most capable of detecting the unusual activity that might be a result of malicious software or hackers, but are too costly to run over the whole network. We develop a fast algorithm to identify tunnelling behaviour at the session level using ‘telescoping ’ of sessions containing other sessions, and demonstrate that this allows a statistical model to be run at scale on netflow timings. The method is applied to a toy dataset using an artificial ‘attack’. I

A Bayesian cluster analysis method for single-molecule localization microscopy data

Cell function is regulated by the spatiotemporal organization of the signaling machinery, and a key facet of this is molecular clustering. Here, we present a protocol for the analysis of clustering in data generated by 2D single-molecule localization microscopy (SMLM)-for example, photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM). Three features of such data can cause standard cluster analysis approaches to be ineffective: (i) the data take the form of a list of points rather than a pixel array; (ii) there is a non-negligible unclustered background density of points that must be accounted for; and (iii) each localization has an associated uncertainty in regard to its position. These issues are overcome using a Bayesian, model-based approach. Many possible cluster configurations are proposed and scored against a generative model, which assumes Gaussian clusters overlaid on a completely spatially random (CSR) background, before every point is scrambled by its localization precision. We present the process of generating simulated and experimental data that are suitable to our algorithm, the analysis itself, and the extraction and interpretation of key cluster descriptors such as the number of clusters, cluster radii and the number of localizations per cluster. Variations in these descriptors can be interpreted as arising from changes in the organization of the cellular nanoarchitecture. The protocol requires no specific programming ability, and the processing time for one data set, typically containing 30 regions of interest, is ∼18 h; user input takes ∼1 h

3D Bayesian cluster analysis of super-resolution data reveals LAT recruitment to the T cell synapse

Single-molecule localisation microscopy (SMLM) allows the localisation of fluorophores with a precision of 10–30 nm, revealing the cell’s nanoscale architecture at the molecular level. Recently, SMLM has been extended to 3D, providing a unique insight into cellular machinery. Although cluster analysis techniques have been developed for 2D SMLM data sets, few have been applied to 3D. This lack of quantification tools can be explained by the relative novelty of imaging techniques such as interferometric photo-activated localisation microscopy (iPALM). Also, existing methods that could be extended to 3D SMLM are usually subject to user defined analysis parameters, which remains a major drawback. Here, we present a new open source cluster analysis method for 3D SMLM data, free of user definable parameters, relying on a model-based Bayesian approach which takes full account of the individual localisation precisions in all three dimensions. The accuracy and reliability of the method is validated using simulated data sets. This tool is then deployed on novel experimental data as a proof of concept, illustrating the recruitment of LAT to the T-cell immunological synapse in data acquired by iPALM providing ~10 nm isotropic resolution. Introduction

Automatic Bayesian single molecule identification for localization microscopy

Single molecule localization microscopy (SMLM) is on its way to become a mainstream imaging technique in the life sciences. However, analysis of SMLM data is biased by user provided subjective parameters required by the analysis software. To remove this human bias we introduce here the Auto-Bayes method that executes the analysis of SMLM data automatically. We demonstrate the success of the method using the photoelectron count of an emitter as selection characteristic. Moreover, the principle can be used for any characteristic that is bimodally distributed with respect to false and true emitters. The method also allows generation of an emitter reliability map for estimating quality of SMLM-based structures. The potential of the Auto-Bayes method is shown by the fact that our first basic implementation was able to outperform all software packages that were compared in the ISBI online challenge in 2015, with respect to molecule detection (Jaccard index)