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Data and modeling code for "History-dependent changes of Gamma distribution in multistable perception" manuscript Raw data can be found in Data folder. Use Compute Perceptual History - * notebooks to generate data files without mixed phases and with perceptual history included (stored in Data with History folder). Use Fitting - * notebooks for fitting of hierarchical Bayesian model.

International audience; An important yet largely unexamined issue is how the interaction between deforestation and pollution affects economic and environmental sustainability.This article seeks to bridge the gap by introducing a dynamic model of pollution accumulation where polluting emissions can be mitigated and the absorption efficiency of pollution sinks can be restored. We assume that emissions are due to a production activity, and we include deforestation both as an additional source of emissions and as a cause of the exhaustion of environmental absorption efficiency. To account for the fact that the switching of natural sinks to a pollution source can be either possible, and in such a case even reversible, or impossible, we consider that restoration efforts can be either independent from or dependent on environmental absorption efficiency, i.e., state-independent versus state-dependent restoration efforts. We determine (i) whether production or deforestation is the most detrimental from environmental and social welfare perspectives, and (ii) how state-dependent restoration process affects pollution accumulation and deforestation policies and the related environmental and social welfare consequences.

Using trading data from a sports wagering market, we estimate individuals’ dynamic risk preferences within a prospect theory paradigm. This market’s experimental-like features facilitate preference estimation, and our long panel enables us to study whether preferences vary across individuals and depend on earlier outcomes. Our estimates extend support for experimental findings—mild utility curvature, moderate loss aversion, and probability overweighting of extreme outcomes—to a market setting and reveal that preferences are heterogeneous and history dependent. Applying our estimates to a portfolio choice problem, we show prospect theory can better explain the prevalence of the disposition effect than previously thought.Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.

Background: Despite the prevalence of hamstring strain injuries and significant research interest, there is debate whether eccentric or isometric muscular contractions are most effective at modifying hamstring strain injury risk and rehabilitating injury. Post-stretch isometric (PS-ISO) contractions, incorporate both eccentric and isometric stimuli and have been shown to enhance isometric torque output, (termed residual force enhancement, rFE). This combination of contraction modes and subsequent effects may be beneficial in hamstring strain injury prevention. It is uncertain whether the hamstrings can generate rFE during PS-ISO contractions in vivo under relevant conditions and whether physical contractile element lengthening would occur in the eccentric phase. It is also unclear whether rFE would endure throughout multiple consecutive PS-ISO contractions as per a resistance training situation., Research Aim: The aim of this thesis was to determine whether the knee flexors can reliably generate rFE during highly controlled PS-ISO contractions under a range of conditions relevant to hamstring strain injury prevention and rehabilitation., Methods: Based on a broader literature review, a series of four studies were conducted targeting the thesis aim. A systematic review of rFE in vivo human muscles using voluntary PS-ISO contractions provided methodology for the three experimental studies. Experimental study one investigated the effects of PS-ISO contractions in the knee flexors using maximal contractions at long musculotendinous unit lengths. Experimental study two investigated the effects of PS-ISO contractions at both maximal and submaximal intensities and over long and short joint rotations. Ultrasonography provided direct muscle and tendon length change analysis of the biceps femoris long-head muscle during PS-ISO contractions. Finally, based, on study one and two, we investigated the effects of PS-ISO contractions under training conditions, a series of sets of consecutive submaximal PS-ISO repetitions., Major Conclusions: The systematic review revealed that rFE of varying magnitude is observable in several muscle/joint arrangements in vivo. The experimental studies provide evidence that rFE was consistently generated in the knee flexors using single and multiple PS-ISO contractions incorporating stretch of the contractile element at maximal and submaximal contraction intensity, without increased muscle activation. We theorise that passive structures within the musculotendinous unit likely contributed additional force. We conclude that PS-ISO are likely to be beneficial in resistance training programs where it is desirable to provide a controlled eccentric stimulus, coupled with elevated isometric torque at lower activation levels. Specifically, there are implications for the potential application of PS-ISO contractions in hamstring strain injury prevention.

Background Following stretch of an active muscle, muscle force is enhanced, which is known as residual force enhancement (rFE). As earlier studies found apparent corticospinal excitability modulations in the presence of rFE, this study aimed to test whether corticospinal excitability modulations contribute to rFE. Methods Fourteen participants performed submaximal plantar flexion stretch-hold and fixed-end contractions at 30% of their maximal voluntary soleus muscle activity in a dynamometer. During the steady state of the contractions, participants either received subthreshold or suprathreshold transcranial magnetic stimulation (TMS) of their motor cortex, while triceps surae muscle responses to stimulation were obtained via electromyography (EMG), and net ankle joint torque was recorded. B-mode ultrasound imaging was used to confirm muscle fascicle stretch during stretch-hold contractions in a subset of participants. Results Following stretch of the plantar flexors, an average rFE of 7% and 11% was observed for contractions with subthreshold and suprathreshold TMS, respectively. 41–46 ms following subthreshold TMS, triceps surae muscle activity was suppressed by 19–25%, but suppression was not significantly different between stretch-hold and fixed-end contractions. Similarly, the reduction in plantar flexion torque following subthreshold TMS was not significantly different between contraction conditions. Motor evoked potentials, silent periods and superimposed twitches following suprathreshold TMS were also not significantly different between contraction conditions. Discussion As TMS of the motor cortex did not result in any differences between stretch-hold and fixed-end contractions, we conclude that rFE is not linked to changes in corticospinal excitability.

Reinforcement learning (RL) models have been widely used to analyze the choice behavior of humans and other animals in a broad range of fields, including psychology and neuroscience. Linear regression-based models that explicitly represent how reward and choice history influences future choices have also been used to model choice behavior. While both approaches have been used independently, the relation between the two models has not been explicitly described. The aim of the present study is to describe this relation and investigate how the parameters in the RL model mediate the effects of reward and choice history on future choices. To achieve these aims, we performed analytical calculations and numerical simulations. First, we describe a special case in which the RL and regression models can provide equivalent predictions of future choices. The general properties of the RL model are discussed as a departure from this special case. We clarify the role of the RL-model parameters, specifically, the learning rate, inverse temperature, and outcome value (also referred to as the reward value, reward sensitivity, or motivational value), in the formation of history dependence.

Memristive materials and devices, which enable information storage and processing on one and the same physical platform, offer an alternative to conventional von Neumann computation architectures. Their continuous spectra of states with intricate field-history dependence give rise to complex dynamics, the spatial aspect of which has not been studied in detail yet. Here, we demonstrate that ferroelectric domain switching induced by a scanning probe microscopy tip exhibits rich pattern dynamics, including intermittency, quasiperiodicity and chaos. These effects are due to the interplay between tip-induced polarization switching and screening charge dynamics, and can be mapped onto the logistic map. Our findings may have implications for ferroelectric storage, nanostructure fabrication and transistor-less logic. © 2014 Macmillan Publishers Limited. All rights reserved.

Recent results have established that Melan's theorem can be applied to discrete elastic systems governed by the Coulomb friction law only when the normal contact reactions are uncoupled from the tangential (slip) displacements. For coupled systems, periodic loading scenarios can be devised which lead to either shakedown or cyclic slip depending on the initial condition. Here we explore this issue in the simplest coupled system involving two contact nodes. The evolution of the system ‘memory’ is conveniently represented graphically by tracking the instantaneous condition in slip-displacement space. The frictional inequalities define directional straight line constraints in this space that tend to ‘sweep’ the operating point towards the safe shakedown condition if one exists. However, if the safe shakedown region is defined by a triangle in which two adjacent sides correspond to the extremal positions of the two frictional constraints for the same node, initial conditions can be found leading to cyclic slip. The critical value of a loading parameter at which this occurs can be determined by requiring that three of the four constraint lines intersect in a point. Below this value, shakedown occurs for all initial conditions. Similar concepts can be extended to multi-node systems.

Muscle contraction has fascinated lay people and scientists for centuries. However, a good understanding of how muscle contraction occurs seemed only possible once microscopy techniques had evolved to a level where basic structural features, such as the regular cross striation patterns of fibers, could be observed in the late 19th century. In the early 20th century, a stimulated muscle was simply considered a new elastic body (Gasser and Hill,1924). Shortening and work production took place with a fixed amount of energy tha twas stored in this body and evolved elastically through stimulation. However, this notion was proven false when Wallace Fenn demonstrated that muscle produced an increasing amount of total energy when increasing its mechanical work output; an observation that was in contradiction with Hill’s elastic body theory (Fenn, 1923,1924). Specifically, Fenn, who worked in the laboratory of Hill and measured heat and work production in frog muscles, found that a muscle allowed to shorten liberated more energy than a muscle held isometrically or a muscle that was stretched. This has become known as the Fenn effect in muscle physiology.

We study collective choice via an endogenous agenda setting process. At each stage, a status quo is implemented unless it is replaced by a majority (winning coalition) with a new status quo outcome. The process continues until the prevailing status quo is no longer challenged. We impose a one-time deviation restriction on the feasible policy processes, reflecting farsightedness of voters. The key feature of the solution is history dependence. The existence of the solution is proven by iterating a version of the uncovered set. We show that the resulting fixed point is the largest set of outcomes that can be implemented via any policy process that meets the one-deviation restriction. Finally, we relate our solution to a concrete noncooperative model, and show that it can be interpreted as a refinement of the solution of Bernheim and Slavov (2009) in the context of repeated voting, and of the solution of Konishi and Ray (2003) and Vartiainen (2011) in the context of coalition formation.

Force enhancement (FE) associated with lengthening is a well-accepted phenomenon of active skeletal muscle, but the underlying mechanism(s) remain unknown. Similar to force depression (FD) following active shortening, the mechanism of FE may be attributed, at least in part, to cross-bridge kinetics. To examine this relationship, a post hoc analysis was performed on the transient force relaxation phase of previous in-situ FE experiments in soleus muscle-tendon units of anesthetized cats. For each muscle (n = 8), nine eccentric lengthenings (3 amplitudes, 3 velocities) were performed while tetanically stimulated (3T at 30 Hz, 39 a motorneuron, 35 � 1°C). To determine transient aspects of FE, the period immediately following stretching was fit with an exponential decay function (R 2 > 0.95). Statistical analyses revealed that total steady-state FE (FESS) increased with stretching amplitude and applied mechanical work. A positive relationship was observed between the active FESS and rate of force decay (k), indicating that a kinetic mechanism may explain active FE. However, for all muscles and stretch conditions, there was no correlation between the total amount of FESS and rate of decay. Therefore, FE cannot be explained solely by an active FE mechanism involving the interaction of actin and myosin. Rather, these findings suggest a combination of underlying mechanisms, including a kinetic mechanism for active FE, contributions of a passive elastic element, and possibly an activatable passive component operating outside of actin–myosin cross-bridging. Moreover, this transient analysis identifies that FE is not simply the opposite of FD, and its underlying mechanism(s) cannot simply be the opposite in nature.

This chapter investigates the implications that social preferences have for the stationary strategic equilibrium of such a decentralized market. Agents are supposed to be averse to unfairly unfavorable as well as unfairly favorable deals in the spirit of Fehr and Schmidt (1999), but we stay rather close to standard individualistic preferences: the negative weights on advantageous and disadvantageous deviations from what is considered as the fair benchmark are such that utility remains strictly increasing in own surplus share. And in contrast to the original Fehr-Schmidt model, the fair split need not automatically be a 50–50 division; any price between sellers’ cost and buyers’ willingness to pay may be the one which—for whatever reasons— is agents’ reference point in a given market. This makes it possible to consider a more flexible notion of fairness than is usually done. It is in line with cognitive dissonance theory from psychology and the noteworthy experiments of Binmore et al. (1991; 1993), where subjects who were triggered to play different bargaining equilibria ended up considering very different surplus distributions as “fair.”

This paper examines monetary policy implementation in a sticky price model. The central bank’s plan under discretionary optimization is entirely forward-looking and exhibits multiple equilibrium solutions if transactions frictions are not negligibly small. The central bank can then implement stable history dependent equilibrium sequences that are consistent with its plan by inertial interest rate adjustments or by money injections. These equilibria are associated with lower welfare losses than a forward-looking solution implemented by interest rate adjustments. The welfare gain from a history dependent implementation is found to rise with the strength of transactions frictions and the degree of price flexibility. It is further shown that the central bank’s plan can uniquely be implemented in a history dependent way by money injections, whereas inertial interest rate adjustments cannot avoid equilibrium multiplicity. JEL Classification: E52, E51, E32

We have developed a label-free conductometric platform for the rapid measurement of kinetics parameters for the adsorption and desorption of proteins on surfaces. Adsorbed Bovine Serum Albumin (BSA) has been detected electrically with response times in the minute range, and kinetic models were elaborated and compared to the measurements. The device presents similar characteristics to Surface Plasmon Resonance (SPR) immunosensors, but takes advantage of a simpler, low-cost electronic measurement unit.