Mediated behavioural change in human-machine networks: exploring network characteristics, trust and motivation

Human-machine networks pervade much of contemporary life. Network change is the product of structural modifications along with differences in participant be-havior. If we assume that behavioural change in a human-machine network is the result of changing the attitudes of participants in the network, then the question arises whether network structure can affect participant attitude. Taking citizen par-ticipation as an example, engagement with relevant stakeholders reveals trust and motivation to be the major objectives for the network. Using a typology to de-scribe network state based on multiple characteristic or dimensions, we can pre-dict possible behavioural outcomes in the network. However, this has to be medi-ated via attitude change. Motivation for the citizen participation network can only increase in line with enhanced trust. The focus for changing network dynamics, therefore, shifts to the dimensional changes needed to encourage increased trust. It turns out that the coordinated manipulation of multiple dimensions is needed to bring about the desired shift in attitude.Comment: Paper submitted to SocInfo, organised by the Oxford Internet Institute, September 201

Robust estimation of microbial diversity in theory and in practice

Quantifying diversity is of central importance for the study of structure, function and evolution of microbial communities. The estimation of microbial diversity has received renewed attention with the advent of large-scale metagenomic studies. Here, we consider what the diversity observed in a sample tells us about the diversity of the community being sampled. First, we argue that one cannot reliably estimate the absolute and relative number of microbial species present in a community without making unsupported assumptions about species abundance distributions. The reason for this is that sample data do not contain information about the number of rare species in the tail of species abundance distributions. We illustrate the difficulty in comparing species richness estimates by applying Chao's estimator of species richness to a set of in silico communities: they are ranked incorrectly in the presence of large numbers of rare species. Next, we extend our analysis to a general family of diversity metrics ("Hill diversities"), and construct lower and upper estimates of diversity values consistent with the sample data. The theory generalizes Chao's estimator, which we retrieve as the lower estimate of species richness. We show that Shannon and Simpson diversity can be robustly estimated for the in silico communities. We analyze nine metagenomic data sets from a wide range of environments, and show that our findings are relevant for empirically-sampled communities. Hence, we recommend the use of Shannon and Simpson diversity rather than species richness in efforts to quantify and compare microbial diversity.Comment: To be published in The ISME Journal. Main text: 16 pages, 5 figures. Supplement: 16 pages, 4 figure

Two Brothers with Skewed Thiopurine Metabolism in Ulcerative Colitis Treated Successfully with Allopurinol and Mercaptopurine Dose Reduction

Thiopurine therapy effectively maintains remission in inflammatory bowel disease. However, many patients are unable to achieve optimum benefits from azathioprine or 6-mercaptopurine because of undesirable metabolism related to high thiopurine methyltransferase (TPMT) activity characterized by hepatic transaminitis secondary to increased 6-methylmercaptopurine (6-MMP) production and reduced levels of therapeutic 6-thioguanine nucleotide (6-TGN). Allopurinol can optimize this skewed metabolism. We discuss two brothers who were both diagnosed with ulcerative colitis (UC). Their disease remained active despite oral and topical mesalamines. Steroids followed by 6-mercaptopurine (MP) were unsuccessfully introduced for both patients and both were found to have high 6-MMP and low 6-TGN levels, despite normal TMPT enzyme activity, accompanied by transaminitis. Allopurinol was introduced in combination with MP dose reduction. For both brothers addition of allopurinol was associated with successful remission and optimized MP metabolites. These siblings with active UC illustrate that skewed thiopurine metabolism may occur despite normal TPMT enzyme activity and can lead to adverse events in the absence of disease control. We confirm previous data showing that addition of allopurinol can reverse this skewed metabolism, and reduce both hepatotoxicity and disease activity, but we now also introduce the concept of a family history of preferential MP metabolism as a clue to effective management for other family members

Plasticity in the Olfactory System: Lessons for the Neurobiology of Memory

We are rapidly advancing toward an understanding of the molecular events underlying odor transduction, mechanisms of spatiotemporal central odor processing, and neural correlates of olfactory perception and cognition. A thread running through each of these broad components that define olfaction appears to be their dynamic nature. How odors are processed, at both the behavioral and neural level, is heavily dependent on past experience, current environmental context, and internal state. The neural plasticity that allows this dynamic processing is expressed nearly ubiquitously in the olfactory pathway, from olfactory receptor neurons to the higher-order cortex, and includes mechanisms ranging from changes in membrane excitability to changes in synaptic efficacy to neurogenesis and apoptosis. This review will describe recent findings regarding plasticity in the mammalian olfactory system that are believed to have general relevance for understanding the neurobiology of memory.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Evidence from GC-TRFLP that Bacterial Communities in Soil Are Lognormally Distributed

The Species Abundance Distribution (SAD) is a fundamental property of ecological communities and the form and formation of SADs have been examined for a wide range of communities including those of microorganisms. Progress in understanding microbial SADs, however, has been limited by the remarkable diversity and vast size of microbial communities. As a result, few microbial systems have been sampled with sufficient depth to generate reliable estimates of the community SAD. We have used a novel approach to characterize the SAD of bacterial communities by coupling genomic DNA fractionation with analysis of terminal restriction fragment length polymorphisms (GC-TRFLP). Examination of a soil microbial community through GC-TRFLP revealed 731 bacterial operational taxonomic units (OTUs) that followed a lognormal distribution. To recover the same 731 OTUs through analysis of DNA sequence data is estimated to require analysis of 86,264 16S rRNA sequences. The approach is examined and validated through construction and analysis of simulated microbial communities in silico. Additional simulations performed to assess the potential effects of PCR bias show that biased amplification can cause a community whose distribution follows a power-law function to appear lognormally distributed. We also show that TRFLP analysis, in contrast to GC-TRFLP, is not able to effectively distinguish between competing SAD models. Our analysis supports use of the lognormal as the null distribution for studying the SAD of bacterial communities as for plant and animal communities

Can Ambient Scent Enhance the Nightlife Experience?

Ever since smoking was prohibited in restaurants, bars, and clubs, undesirable smells that were previously masked by cigarette smoke became noticeable. This opens up opportunities to improve the dance club environment by introducing pleasant ambient scents that mask the unwanted odors and to allow competing clubs to differentiate themselves. A field study was conducted at three dance clubs using a 3 × 3 Latin square design with pre- and post-measurements of no-scent control conditions. The three scents tested were orange, seawater, and peppermint. These scents were shown to enhance dancing activity and to improve the evaluation of the evening, the evaluation of the music, and the mood of the visitors over no added scent. However, no significant differences were found between the three scents

DiapixUK: task materials for the elicitation of multiple spontaneous speech dialogs

The renewed focus of attention on investigating spontaneous speech samples in speech and language research has increased the need for recordings of speech in interactive settings. The DiapixUK task is a new and extended set of picture materials based on the Diapix task by Van Engen et al. (2010) where two people are recorded while conversing to solve a ‘spot the difference’ task. The new task materials allow for multiple recordings of the same speaker pairs due to a larger set of picture pairs which have a number of tested features: equal difficulty across all twelve picture pairs, no learning effect of completing more than one picture task and balanced contributions from both speakers. The new materials also provide extra flexibility making them useful in a wide range of research projects; they are multi-layered electronic images that can be adapted to suit different research needs. This paper presents details of the development of the DiapixUK materials along with data taken from a large corpus of spontaneous speech which demonstrate its new features. Current and potential applications of the task are also discussed

Increased indoleamine-2,3-dioxygenase activity is associated with poor clinical outcome in adults hospitalized with influenza in the INSIGHT FLU003Plus study

BACKGROUND: Indoleamine-2,3-dioxygenase (IDO) mediated tryptophan (TRP) depletion has antimicrobial and immuno-regulatory effects. Increased kynurenine (KYN)-to-TRP (KT) ratios, reflecting increased IDO activity, have been associated with poorer outcomes from several infections. METHODS: We performed a case-control (1:2; age and sex matched) analysis of adults hospitalized with influenza A(H1N1)pdm09 with protocol-defined disease progression (died/transferred to ICU/mechanical ventilation) after enrollment (cases) or survived without progression (controls) over 60 days of follow-up. Conditional logistic regression was used to analyze the relationship between baseline KT ratio and other metabolites and disease progression. RESULTS: We included 32 cases and 64 controls with a median age of 52 years; 41% were female, and the median durations of influenza symptoms prior to hospitalization were 8 and 6 days for cases and controls, respectively (P = .04). Median baseline KT ratios were 2-fold higher in cases (0.24 mM/M; IQR, 0.13-0.40) than controls (0.12; IQR, 0.09-0.17; P ≤ .001). When divided into tertiles, 59% of cases vs 20% of controls had KT ratios in the highest tertile (0.21-0.84 mM/M). When adjusted for symptom duration, the odds ratio for disease progression for those in the highest vs lowest tertiles of KT ratio was 9.94 (95% CI, 2.25-43.90). CONCLUSIONS: High KT ratio was associated with poor outcome in adults hospitalized with influenza A(H1N1)pdm09. The clinical utility of this biomarker in this setting merits further exploration. CLINICALTRIALSGOV IDENTIFIER: NCT01056185

Psycholinguistic variables matter in odor naming

People from Western societies generally find it difficult to name odors. In trying to explain this, the olfactory literature has proposed several theories that focus heavily on properties of the odor itself but rarely discuss properties of the label used to describe it. However, recent studies show speakers of languages with dedicated smell lexicons can name odors with relative ease. Has the role of the lexicon been overlooked in the olfactory literature? Word production studies show properties of the label, such as word frequency and semantic context, influence naming; but this field of research focuses heavily on the visual domain. The current study combines methods from both fields to investigate word production for olfaction in two experiments. In the first experiment, participants named odors whose veridical labels were either high-frequency or low-frequency words in Dutch, and we found that odors with high-frequency labels were named correctly more often. In the second experiment, edibility was used for manipulating semantic context in search of a semantic interference effect, presenting the odors in blocks of edible and inedible odor source objects to half of the participants. While no evidence was found for a semantic interference effect, an effect of word frequency was again present. Our results demonstrate psycholinguistic variables-such as word frequency-are relevant for olfactory naming, and may, in part, explain why it is difficult to name odors in certain languages. Olfactory researchers cannot afford to ignore properties of an odor's label