Genetic diversity and differentiation processes in the ploidy series of Olea europaea L.: a multiscale approach from subspecies to insular populations.

Geographical isolation and polyploidization are central concepts in plant evolution. The hierarchical organization of archipelagos in this study provides a framework for testing the evolutionary consequences for polyploid taxa and populations occurring in isolation. Using amplified fragment length polymorphism and simple sequence repeat markers, we determined the genetic diversity and differentiation patterns at three levels of geographical isolation in Olea europaea: mainland-archipelagos, islands within an archipelago, and populations within an island. At the subspecies scale, the hexaploid ssp. maroccana (southwest Morocco) exhibited higher genetic diversity than the insular counterparts. In contrast, the tetraploid ssp. cerasiformis (Madeira) displayed values similar to those obtained for the diploid ssp. guanchica (Canary Islands). Geographical isolation was associated with a high genetic differentiation at this scale. In the Canarian archipelago, the stepping-stone model of differentiation suggested in a previous study was partially supported. Within the western lineage, an east-to-west differentiation pattern was confirmed. Conversely, the easternmost populations were more related to the mainland ssp. europaea than to the western guanchica lineage. Genetic diversity across the Canarian archipelago was significantly correlated with the date of the last volcanic activity in the area/island where each population occurs. At the island scale, this pattern was not confirmed in older islands (Tenerife and Madeira), where populations were genetically homogeneous. In contrast, founder effects resulted in low genetic diversity and marked genetic differentiation among populations of the youngest island, La Palma.

Does Semantic Context Benefit Speech Understanding through "Top-Down" Processes? Evidence from Time-resolved Sparse fMRI.

When speech is degraded, word report is higher for semantically coherent sentences (e.g., her new skirt was made of denim) than for anomalous sentences (e.g., her good slope was done in carrot). Such increased intelligibility is often described as resulting from "top-down" processes, reflecting an assumption that higher-level (semantic) neural processes support lower-level (perceptual) mechanisms. We used time-resolved sparse fMRI to test for top-down neural mechanisms, measuring activity while participants heard coherent and anomalous sentences presented in speech envelope/spectrum noise at varying signal-to-noise ratios (SNR). The timing of BOLD responses to more intelligible speech provides evidence of hierarchical organization, with earlier responses in peri-auditory regions of the posterior superior temporal gyrus than in more distant temporal and frontal regions. Despite Sentence content × SNR interactions in the superior temporal gyrus, prefrontal regions respond after auditory/perceptual regions. Although we cannot rule out top-down effects, this pattern is more compatible with a purely feedforward or bottom-up account, in which the results of lower-level perceptual processing are passed to inferior frontal regions. Behavioral and neural evidence that sentence content influences perception of degraded speech does not necessarily imply "top-down" neural processes.

Affirmative Action Policy and Effort Levels. Sequential-Move Contest Game Argument

In this paper we analyse a simple two-person sequential-move contest game with heterogeneous players. Assuming that the heterogeneity could be the consequence of past discrimination, we study the effects of implementation of affirmative action policy, which tackles this heterogeneity by compensating discriminated players, and compare them with the situation in which the heterogeneity is ignored and the contestants are treated equally. In our analysis we consider different orders of moves. We show that the order of moves of contestants is a very important factor in determination of the effects of the implementation of the affirmative action policy. We also prove that in such cases a significant role is played by the level of the heterogeneity of individuals. In particular, in contrast to the present-in-the-literature predictions, we demonstrate that as a consequence of the interplay of these two factors, the response to the implementation of the affirmative action policy option may be the decrease in the total equilibrium effort level of the contestants in comparison to the unbiased contest game.

Fact And Fiction In FX Arbitrage Processes

The efficient markets hypothesis implies that arbitrage opportunities in markets such as those for foreign exchange (FX) would be, at most, short-lived. The present paper surveys the fragmented nature of FX markets, revealing that information in these markets is also likely to be fragmented. The “quant” workforce in the hedge fund featured in The Fear Index novel by Robert Harris would have little or no reason for their existence in an EMH world. The four currency combinatorial analysis of arbitrage sequences contained in Cross, Kozyakin, O’Callaghan, Pokrovskii and Pokrovskiy (2012) is then considered. Their results suggest that arbitrage processes, rather than being self-extinguishing, tend to be periodic in nature. This helps explain the fact that arbitrage dealing tends to be endemic in FX markets.

Fact And Fiction In FX Arbitrage Processes

The efficient markets hypothesis implies that arbitrage opportunities in markets such as those for foreign exchange (FX) would be, at most, short-lived. The present paper surveys the fragmented nature of FX markets, revealing that information in these markets is also likely to be fragmented. The “quant” workforce in the hedge fund featured in The Fear Index novel by Robert Harris would have little or no reason for their existence in an EMH world. The four currency combinatorial analysis of arbitrage sequences contained in Cross, Kozyakin, O’Callaghan, Pokrovskii and Pokrovskiy (2012) is then considered. Their results suggest that arbitrage processes, rather than being self-extinguishing, tend to be periodic in nature. This helps explain the fact that arbitrage dealing tends to be endemic in FX markets.

Nano-electro-mechanical in dynamical cellular processes

Report for the scientific sojourn carried out at the Department of Structure and Constituents of Matter during 2007.The main focus of the work was on phenomena related to nano-electromechanical processes that take place on a cellular level. Additionally, it has also been performed independent work related to charge and energy transfer in bio molecules, energy transfer in coupled spin systems as well as electrodynamics of nonlinear metamaterials.

Class-size Reduction Policies and the Quality of Entering Teachers

State-wide class-size reduction (CSR) policies have typically failed to produce large achievement gains. One explanation is that the introduction of such policies forces schools to hire relatively low-quality teachers. This paper uses data from an anonymous state to explore whether teacher quality suff ered from the introduction of CSR. We find that it did, but not nearly enough to explain the small achievement effects of CSR. The combined fall in achievement due to hiring lower quality teachers and more inexperienced teachers is small relative to the unrealized gains. Furthermore, between-school diff erences in the quality of incoming teachers cannot explain the poor estimated CSR performance from previous quasi-experimental treatment-control comparisons.

Fact And Fictions In FX Arbitrage Processes

The efficient markets hypothesis implies that arbitrage opportunities in markets such as those for foreign exchange (FX) would be, at most, short-lived. The present paper surveys the fragmented nature of FX markets, revealing that information in these markets is also likely to be fragmented. The “quant” workforce in the hedge fund featured in The Fear Index novel by Robert Harris would have little or no reason for their existence in an EMH world. The four currency combinatorial analysis of arbitrage sequences contained in Cross, Kozyakin, O’Callaghan, Pokrovskii and Pokrovskiy (2012) is then considered. Their results suggest that arbitrage processes, rather than being self-extinguishing, tend to be periodic in nature. This helps explain the fact that arbitrage dealing tends to be endemic in FX markets.

Quantifying rates of landscape evolution and tectonic processes by thermochronology and numerical modeling of crustal heat transport using PECUBE

PECUBE is a three-dimensional thermal-kinematic code capable of solving the heat production-diffusion-advection equation under a temporally varying surface boundary condition. It was initially developed to assess the effects of time-varying surface topography (relief) on low-temperature thermochronological datasets. Thermochronometric ages are predicted by tracking the time-temperature histories of rock-particles ending up at the surface and by combining these with various age-prediction models. In the decade since its inception, the PECUBE code has been under continuous development as its use became wider and addressed different tectonic-geomorphic problems. This paper describes several major recent improvements in the code, including its integration with an inverse-modeling package based on the Neighborhood Algorithm, the incorporation of fault-controlled kinematics, several different ways to address topographic and drainage change through time, the ability to predict subsurface (tunnel or borehole) data, prediction of detrital thermochronology data and a method to compare these with observations, and the coupling with landscape-evolution (or surface-process) models. Each new development is described together with one or several applications, so that the reader and potential user can clearly assess and make use of the capabilities of PECUBE. We end with describing some developments that are currently underway or should take place in the foreseeable future. (C) 2012 Elsevier B.V. All rights reserved.

The effectiveness and safety of rescue treatments in 108 patients with steroid-refractory ulcerative colitis with sequential rescue therapies in a subgroup of patients.

BACKGROUND: Among patients with steroid-refractory ulcerative colitis (UC) in whom a first rescue therapy has failed, a second line salvage treatment can be considered to avoid colectomy. AIM: To evaluate the efficacy and safety of second or third line rescue therapy over a one-year period. METHODS: Response to single or sequential rescue treatments with infliximab (5mg/kg intravenously (iv) at week 0, 2, 6 and then every 8weeks), ciclosporin (iv 2mg/kg/daily and then oral 5mg/kg/daily) or tacrolimus (0.05mg/kg divided in 2 doses) in steroid-refractory moderate to severe UC patients from 7 Swiss and 1 Serbian tertiary IBD centers was retrospectively studied. The primary endpoint was the one year colectomy rate. RESULTS: 60% of patients responded to the first rescue therapy, 10% went to colectomy and 30% non-responders were switched to a 2(nd) line rescue treatment. 66% of patients responded to the 2(nd) line treatment whereas 34% failed, of which 15% went to colectomy and 19% received a 3(rd) line rescue treatment. Among those, 50% patients went to colectomy. Overall colectomy rate of the whole cohort was 18%. Steroid-free remission rate was 39%. The adverse event rates were 33%, 37.5% and 30% for the first, second and third line treatment respectively. CONCLUSION: Our data show that medical intervention even with 2(nd) and 3(rd) rescue treatments decreased colectomy frequency within one year of follow up. A longer follow-up will be necessary to investigate whether sequential therapy will only postpone colectomy and what percentage of patients will remain in long-term remission.