Logics of Finite Hankel Rank

We discuss the Feferman-Vaught Theorem in the setting of abstract model theory for finite structures. We look at sum-like and product-like binary operations on finite structures and their Hankel matrices. We show the connection between Hankel matrices and the Feferman-Vaught Theorem. The largest logic known to satisfy a Feferman-Vaught Theorem for product-like operations is CFOL, first order logic with modular counting quantifiers. For sum-like operations it is CMSOL, the corresponding monadic second order logic. We discuss whether there are maximal logics satisfying Feferman-Vaught Theorems for finite structures.Comment: Appeared in YuriFest 2015, held in honor of Yuri Gurevich's 75th birthday. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-23534-9_1

Tavistock Adult Depression Study (TADS): a randomised controlled trial of psychoanalytic psychotherapy for treatment-resistant/treatment-refractory forms of depression

ABSTRACT: BACKGROUND: Long-term forms of depression represent a significant mental health problem for which there is a lack of effective evidence-based treatment. This study aims to produce findings about the effectiveness of psychoanalytic psychotherapy in patients with treatment-resistant/treatment-refractory depression and to deepen the understanding of this complex form of depression. METHODS: INDEX GROUP: Patients with treatment resistant/treatment refractory depression. DEFINITION & INCLUSION CRITERIA: Current major depressive disorder, 2 years history of depression, a minimum of two failed treatment attempts, [greater than or equal to]14 on the HRSD or [greater than or equal to]21 on the BDI, plus complex personality and/or psycho-social difficulties. EXCLUSION CRITERIA: Moderate or severe learning disability, psychotic illness, bipolar disorder, substance dependency or receipt of test intervention in the previous two years. DESIGN: Pragmatic, randomised controlled trial with qualitative and clinical components. TEST INTERVENTION: 18 months of weekly psychoanalytic psychotherapy, manualised and fidelity-assessed using the Psychotherapy Process Q-Sort. CONTROL CONDITION: Treatment as usual, managed by the referring practitioner. RECRUITMENT: GP referrals from primary care. RCT MAIN OUTCOME: HRSD (with [less than or equal to]14 as remission). SECONDARY OUTCOMES: depression severity (BDI-II), degree of co-morbid disorders Axis-I and Axis-II (SCID-I and SCID-II-PQ), quality of life and functioning (GAF, CORE, Q-les-Q), object relations (PROQ2a), Cost-effectiveness analysis (CSRI and GP medical records). FOLLOW-UP: 2 years. Plus: a). Qualitative study of participants' and therapists' problem formulation, experience of treatment and of participation in trial. (b) Narrative data from semi-structured pre/post psychodynamic interviews to produce prototypes of responders and non-responders. (c) Clinical case-studies of sub-types of TRD and of change. DISCUSSION: TRD needs complex, long-term intervention and extended research follow-up for the proper evaluation of treatment outcome. This pushes at the limits of the design of randomised therapeutic trials,. We discuss some of the consequent problems and suggest how they may be mitigated. Trial registration Current Controlled Trials ISRCTN40586372

Non-negative Spectral Learning for Linear Sequential Systems

International audienceMethod of moments (MoM) has recently become an appealing alternative to standard iterative approaches like Expectation Maximization (EM) to learn latent variable models. In addition, MoM-based algorithms come with global convergence guarantees in the form of finite sample bounds. However, given enough computation time, by using restarts and heuristics to avoid local optima, iterative approaches often achieve better performance. We believe that this performance gap is in part due to the fact that MoM-based algorithms can output negative probabilities. By constraining the search space, we propose a non-negative spectral algorithm (NNSpectral) avoiding computing negative probabilities by design. NNSpectral is compared to other MoM-based algorithms and EM on synthetic problems of the PAutomaC challenge. Not only, NNSpectral outperforms other MoM-based algorithms, but also, achieves very competitive results in comparison to EM

Does the temperature sensitivity of decomposition of soil organic matter depend upon water content, soil horizon, or incubation time?

Several studies have shown multiple confounding factors influencing soil respiration in the field, which often hampers a correct separation and interpretation of the different environmental effects on respiration. Here, we present a controlled laboratory experiment on undisturbed organic and mineral soil cores separating the effects of temperature, drying–rewetting and decomposition dynamics on soil respiration. Specifically, we address the following questions: (1) Is the temperature sensitivity of soil respiration (Q10) dependent on soil moisture or soil organic matter age (incubation time) and does it differ for organic and mineral soil as suggested by recent field studies. (2) How much do organic and mineral soil layers contribute to total soil respiration? (3) Is there potential to improve soil flux models of soil introducing a multilayer source model for soil respiration? Eight organic soil and eight mineral soil cores were taken from a Norway spruce (Picea abies) stand in southern Germany, and incubated for 90 days in a climate chamber with a diurnal temperature regime between 7 and 23 1C. Half of the samples were rewetted daily, while the other half were left to dry and rewetted thereafter. Soil respiration was measured with a continuously operating open dynamic soil respiration chamber system. The Q10 was stable at around 2.7, independent of soil horizon and incubation time, decreasing only slightly when the soil dried. We suggest that recent findings of the Q10 dependency on several factors are emergent properties at the ecosystem level, that should be analysed further e.g. with regard to rhizosphere effects. Most of the soil CO2 efflux was released from the organic samples. Initially, it averaged 4.0 lmolm 2 s 1 and declined to 1.8 lmolm 2 s 1 at the end of the experiment. In terms of the third question, we show that models using only one temperature as predictor of soil respiration fail to explain more than 80% of the diurnal variability, are biased with a hysteresis effect, and slightly underestimate the temperature sensitivity of respiration. In contrast, consistently more than 95% of the diurnal variability is explained by a dual-source model, with one CO2 source related to the surface temperature and another CO2 source related to the central temperature, highlighting the role of soil surface processes for ecosystem carbon balance