Applicative theories for logarithmic complexity classes

We present applicative theories of words corresponding to weak, and especially logarithmic, complexity classes. The theories for the logarithmic hierarchy and alternating logarithmic time formalise function algebras with concatenation recursion as main principle. We present two theories for logarithmic space where the first formalises a new two-sorted algebra which is very similar to Cook and Bellantoni's famous two-sorted algebra B for polynomial time [4]. The second theory describes logarithmic space by formalising concatenation- and sharply bounded recursion. All theories contain the predicates WW representing words, and VV representing temporary inaccessible words. They are inspired by Cantini's theories [6] formalising B.

Darwin's multicellularity: from neurotrophic theories and cell competition to fitness fingerprints

Metazoans have evolved ways to engage only the most appropriate cells for long-term tissue development and homeostasis. In many cases, competitive interactions have been shown to guide such cell selection events. In Drosophila, a process termed cell competition eliminates slow proliferating cells from growing epithelia. Recent studies show that cell competition is conserved in mammals with crucial functions like the elimination of suboptimal stem cells from the early embryo and the replacement of old T-cell progenitors in the thymus to prevent tumor formation. Moreover, new data in Drosophila has revealed that fitness indicator proteins, required for cell competition, are also involved in the culling of retinal neurons suggesting that 'fitness fingerprints' may play a general role in cell selection.

Brain systems underlying encounter expectancy bias in spider phobia.

Spider-phobic individuals are characterized by exaggerated expectancies to be faced with spiders (so-called encounter expectancy bias). Whereas phobic responses have been linked to brain systems mediating fear, little is known about how the recruitment of these systems relates to exaggerated expectancies of threat. We used fMRI to examine spider-phobic and control participants while they imagined visiting different locations in a forest after having received background information about the likelihood of encountering different animals (spiders, snakes, and birds) at these locations. Critically, imagined encounter expectancies modulated brain responses differently in phobics as compared with controls. Phobics displayed stronger negative modulation of activity in the lateral prefrontal cortex, precuneus, and visual cortex by encounter expectancies for spiders, relative to snakes or birds (within-participants analysis); these effects were not seen in controls. Between-participants correlation analyses within the phobic group further corroborated the hypothesis that these phobia-specific modulations may underlie irrationality in encounter expectancies (deviations of encounter expectancies from objective background information) in spider phobia; the greater the negative modulation a phobic participant displayed in the lateral prefrontal cortex, precuneus, and visual cortex, the stronger was her bias in encounter expectancies for spiders. Interestingly, irrationality in expectancies reflected in frontal areas relied on right rather than left hemispheric deactivations. Our data accord with the idea that expectancy biases in spider phobia may reflect deficiencies in cognitive control and contextual integration that are mediated by right frontal and parietal areas.

Evidence for an encounter expectancy bias in fear of spiders.

Whereas research has demonstrated that phobic or fearful individuals overestimate the likelihood of incurring aversive consequences from an encounter with feared stimuli, it has not yet been systematically investigated whether these individuals also overestimate the likelihood (i.e., the frequency) of such encounters. In the current study, spider-fearful and control participants were presented with background information that allowed them to estimate the overall likelihood that different kinds of animals (spiders, snakes, or birds) would be encountered. Spider-fearful participants systematically overestimated the likelihood of encountering a spider with respect to the likelihood of encountering a snake or a bird. No such expectancy bias was observed in control participants. The results thus strengthen our idea that there indeed exist two different types of expectancy bias in high fear and phobia that can be related to different components of the fear response. A conscientious distinction and examination of these two types of expectancy bias are of potential interest for therapeutic applications.

On supergravity theories, after ∼ 40 years

An introduction to and a partial review of supergravity theories is given, insisting on concepts and on some important technical aspects. Topics covered include elements of global supersymmetry, a derivation of the simplest N = 1 supergravity theory, a discussion of N =1 matter-supergravity couplings, of the scalar sector and of some simple models. Space-time is four-dimensional.

Sport Psychology. Theories and Applications for Performance, Health and Humanity.

This congress proceedings volume includes all abstracts submitted to the 14th European Congress of Sport Psychology of the European Federation of Sport Psychology FEPSAC that have been accepted by the scientific evaluation committee. Content: six keynote lectures, Panteleimon ("Paddy") Ekkekakis: Escape from Cognitivism: Exercise as Hedonic Experience; Sergio Lara-Bercial and Cliff Mallett: Serial Winning Coaches – Vision, People and Environment; Kari Fasting: Sexual Harassment and Abuse in Sport – Implications for Sport Psychologists; Claudia Voelcker-Rehage: Benefits of Physical Activity and Fitness for Lifelong Motor and Cognitive Development – Brain and Behaviour; Nancy J. Cooke: Interactive Team Cognition: Focusing on Team Dynamics; Chris Harwood: Doing Sport Psychology? Critical Reflections as a Scientist-Practitioner. Abstracts of 11 invited symposia, 65 submitted symposia, 8 special sessions, and 5 poster sessions.

Modeling absolute differences in life expectancy with a censored skew-normal regression approach.

Parameter estimates from commonly used multivariable parametric survival regression models do not directly quantify differences in years of life expectancy. Gaussian linear regression models give results in terms of absolute mean differences, but are not appropriate in modeling life expectancy, because in many situations time to death has a negative skewed distribution. A regression approach using a skew-normal distribution would be an alternative to parametric survival models in the modeling of life expectancy, because parameter estimates can be interpreted in terms of survival time differences while allowing for skewness of the distribution. In this paper we show how to use the skew-normal regression so that censored and left-truncated observations are accounted for. With this we model differences in life expectancy using data from the Swiss National Cohort Study and from official life expectancy estimates and compare the results with those derived from commonly used survival regression models. We conclude that a censored skew-normal survival regression approach for left-truncated observations can be used to model differences in life expectancy across covariates of interest.

The M-theory origin of global properties of gauge theories

We show that global properties of gauge groups can be understood as geometric properties in M-theory. Different wrappings of a system of N M5-branes on a torus reduce to four-dimensional theories with AN−1 gauge algebra and different unitary groups. The classical properties of the wrappings determine the global properties of the gauge theories without the need to impose any quantum conditions. We count the inequivalent wrappings as they fall into orbits of the modular group of the torus, which correspond to the S-duality orbits of the gauge theories.

A Proof-Theoretic Analysis of Theories for Stratified Inductive Definitions

In this article we study subsystems SIDᵥ of the theory ID₁ in which fixed point induction is restricted to properly stratified formulas.

Trends in life expectancy of HIV-positive adults on antiretroviral therapy across the globe: comparisons with general population.

PURPOSE OF REVIEW Improved virological and immunological outcomes and reduced toxicity of antiretroviral combination therapy (ART) raise the hope that life expectancy of HIV-positive persons on ART will approach that of the general population. We systematically review the literature and summarize published estimates of life expectancy of HIV-positive populations on ART. We compare their life expectancy with the life expectancy of the general or, in sub-Saharan Africa, HIV-negative populations, by time period and gender. RECENT FINDINGS Ten relevant studies were published from 2006 to 2015. Three studies were from Canada, two from European countries, three from sub-Saharan Africa and two were multicountry studies. Life expectancy increased over time in all studies and regions. Expressed as the percentage of life expectancy in the HIV-negative or general population, estimated life expectancy at age 20 years in HIV-positive people on ART ranged from 60.3% (95% CI 58.0-62.6%) in Rwanda (2008-2011) to 89.1% (95% CI 84.7-93.6%) in Canada (2008-2012). The percentage of life expectancy in the HIV-negative or general population achieved was higher in HIV-positive women than in HIV-positive men in all countries, except for Canada wherein the opposite was the case. SUMMARY Life expectancy in HIV-positive people on ART has improved worldwide in recent years, but important gaps remain compared with the general and HIV-negative population, and between regions and genders.

The Reference Interview: Theories and Practice

The reference librarian's task is to translate the patron's question into one that can be answered with the library's resources. The first element of that task is to know what the patron wants; the second is to know what resources the library has and how to use them. Reference librarians must learn continuously throughout their careers, both because new resources become available, but also because patrons present questions requiring new resources. This article will focus on how to determine what kind of information the patron needs through the reference interview.