Fibers and global geometry of functions

Since the seminal work of Ambrosetti and Prodi, the study of global folds was enriched by geometric concepts and extensions accomodating new examples. We present the advantages of considering fibers, a construction dating to Berger and Podolak's view of the original theorem. A description of folds in terms of properties of fibers gives new perspective to the usual hypotheses in the subject. The text is intended as a guide, outlining arguments and stating results which will be detailed elsewhere

Statistical Language Modelling

Grammar-based natural language processing has reached a level where it can `understand' language to a limited degree in restricted domains. For example, it is possible to parse textual material very accurately and assign semantic relations to parts of sentences. An alternative approach originates from the work of Shannon over half a century ago [41], [42]. This approach assigns probabilities to linguistic events, where mathematical models are used to represent statistical knowledge. Once models are built, we decide which event is more likely than the others according to their probabilities. Although statistical methods currently use a very impoverished representation of speech and language (typically finite state), it is possible to train the underlying models from large amounts of data. Importantly, such statistical approaches often produce useful results. Statistical approaches seem especially well-suited to spoken language which is often spontaneous or conversational and not readily amenable to standard grammar-based approaches

Can high resolution 3D topographic surveys provide reliable grain size estimates in gravel bed rivers?

High resolution topographic surveys such as those provided by Structure-from-Motion (SfM) contain a wealth of information that is not always exploited in the generation of Digital Elevation Models (DEMs). In particular, several authors have related sub-metre scale topographic variability (or ‘surface roughness’) to sediment grain size by deriving empirical relationships between the two. In fluvial applications, such relationships permit rapid analysis of the spatial distribution of grain size over entire river reaches, providing improved data to drive three-dimensional hydraulic models, allowing rapid geomorphic monitoring of sub-reach river restoration projects, and enabling more robust characterisation of riverbed habitats. However, comparison of previously published roughness-grain-size relationships shows substantial variability between field sites. Using a combination of over 300 laboratory and field-based SfM surveys, we demonstrate the influence of inherent survey error, irregularity of natural gravels, particle shape, grain packing structure, sorting, and form roughness on roughness-grain-size relationships. Roughness analysis from SfM datasets can accurately predict the diameter of smooth hemispheres, though natural, irregular gravels result in a higher roughness value for a given diameter and different grain shapes yield different relationships. A suite of empirical relationships is presented as a decision tree which improves predictions of grain size. By accounting for differences in patch facies, large improvements in D50 prediction are possible. SfM is capable of providing accurate grain size estimates, although further refinement is needed for poorly sorted gravel patches, for which c-axis percentiles are better predicted than b-axis percentiles

Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

Function and processing of gesture in the context of language

Most research focuses function of gesture independent of its link to the speech it accompanies and the coexpressive functions it has together with speech. This chapter instead approaches gesture in relation to its communicative function in relation to speech, and demonstrates how it is shaped by the linguistic encoding of a speaker's message. Drawing on crosslinguistic research with adults and children as well as bilinguals on iconic/pointing gesture production it shows that the specific language speakers use modulates the rate and the shape of the iconic gesture production of the same events. The findings challenge the claims aiming to understand gesture's function for "thinking only" in adults and during development

BDNF Val66Met polymorphism as a moderator of exercise enhancement of smoking cessation treatment in anxiety vulnerable adults

Background: Exercise interventions facilitate the odds of quit success among high-anxiety sensitive adults smokers. We examined the dependency of these benefits on the genetic BDNF Val66Met (rs6265) polymorphism; individuals who are Met carriers have lower BDNF responses and reduced associated benefits from exercise. Accordingly, we hypothesized that the efficacy of vigorous-intensity exercise for smoking cessation would be specific to high-anxiety sensitive Val/Val carriers. Methods: Participants were adults (N = 55) of European ancestry who had participated in a randomized controlled trial comparing a smoking cessation program augmented with exercise vs. augmented with a wellness control treatment. In this secondary analysis, growth curve models for point-prevalence abstinence (PPA) and prolonged abstinence (PA) employed for the main outcome analyses were amended to test the moderator effects of the BDNF Val66Met polymorphism. Results: Consistent with prediction, the advantage of exercise over control for PPA was significantly greater among high-anxiety sensitive persons with the Val/Val genotype than for those with the Val/Met genotype. This advantage did not reach statistical significance for PA. Differences in abstinence between the exercise and control interventions among low-anxiety sensitive smokers were not dependent on the BDNF Val66Met polymorphism. Conclusions: We found that the efficacy of exercise for augmenting smoking cessation treatment is intensified among high-anxiety sensitive smokers who are Val/Val carriers. This observation is consistent with findings documenting BDNF mediation of exercise benefits and greater negative affect among smokers who are Val/Val carriers. These data encourage further evaluation of the association between the BDNF polymorphism, exercise, anxiety sensitivity, and smoking cessation

Anxiety sensitivity and smoking variability among treatment seeking smokers

Objectives: Anxiety sensitivity (AS) is associated with poor smoking cessation outcomes. One reason may be that smokers with high AS smoke differently (ie, to manage negative affect and uncomfortable bodily sensations) than other smokers, leading to stronger addiction (due to an affect/sensation based and thereby highly variable rather than a regular smoking routine). Thus, we examined the relationship between AS and smoking variability in a group of treatment-seeking smokers. Methods: Participants (N=136; 52.2% female; Mage=44.19 y, SD=11.29) were daily smokers with elevated AS (AS>=20 on the Anxiety Sensitivity Index 16-item at prescreen) recruited as part of a larger randomized controlled trial for smoking cessation. Most participants were white (73%), educated (with 76% attending some college), unmarried (73%), and employed full-time (56%). They smoked, on average, 17 cigarettes per day. Results: Consistent with prediction, a regression analysis of baseline assessments and a longitudinal analysis with multilevel modeling both showed higher AS was associated with greater variability in cigarettes smoked per day while controlling for sex, age, ethnicity, and income. Conclusions: This finding encourages investigation of how AS might interact with clinical strategies using a fixed smoking taper as part of quit attempts

Exercise self-efficacy moderates the relation between anxiety sensitivity and body mass index and exercise tolerance in treatment-seeking smokers

There is little known about factors that contribute to the comorbidity of cigarette smoking and obesity. The current study sought to test whether exercise self-efficacy moderated the relation between anxiety sensitivity (fear of internal sensations) and BMI and exercise tolerance among cigarette smokers. Smokers (n = 72; 50% female; Mcpd = 19.3, SD = 10.65) were recruited to participate in a smoking cessation treatment trial. During medical screen, we measured weight, height, and exercise tolerance (functional capacity) employing a standardized maximal exercise testing protocol. After adjusting for participant sex and cigarettes per day, exercise self-efficacy moderated the association between anxiety sensitivity and BMI, such that the positive association between anxiety sensitivity and BMI was significantly stronger when exercise self-efficacy was low. The same pattern of results emerged for exercise tolerance. Exercise self-efficacy moderated the association between anxiety sensitivity and exercise tolerance, such that the negative association between anxiety sensitivity and exercise tolerance was significantly stronger when exercise self-efficacy was low. Among smokers, anxiety sensitivity may be a risk variable that, directly and indirectly in the context of low self-efficacy for exercise, causes or maintains higher body weight and lower exercise tolerance