Winning versus losing during gambling and its neural correlates

Humans often make decisions which maximize an internal utility function. For example, humans often maximize their expected reward when gambling and this is considered as a "rational" decision. However, humans tend to change their betting strategies depending on how they "feel". If someone has experienced a losing streak, they may "feel" that they are more likely to win on the next hand even though the odds of the game have not changed. That is, their decisions are driven by their emotional state. In this paper, we investigate how the human brain responds to wins and losses during gambling. Using a combination of local field potential recordings in human subjects performing a financial decision-making task, spectral analyses, and non-parametric cluster statistics, we investigated whether neural responses in different cognitive and limbic brain areas differ between wins and losses after decisions are made. In eleven subjects, the neural activity modulated significantly between win and loss trials in one brain region: the anterior insula ($p=0.01$). In particular, gamma activity (30-70 Hz) increased in the anterior insula when subjects just realized that they won. Modulation of metabolic activity in the anterior insula has been observed previously in functional magnetic resonance imaging studies during decision making and when emotions are elicited. However, our study is able to characterize temporal dynamics of electrical activity in this brain region at the millisecond resolution while decisions are made and after outcomes are revealed

Internal states as a source of subject-dependent movement variability and their representation by large-scale networks

AbstractA human’s ability to adapt and learn relies on reflecting on past performance. Such reflections form latent factors called internal states that induce variability of movement and behavior to improve performance. Internal states are critical for survival, yet their temporal dynamics and neural substrates are less understood. Here, we link internal states with motor performance and neural activity using state-space models and local field potentials captured from depth electrodes in over 100 brain regions. Ten human subjects performed a goal-directed center-out reaching task with perturbations applied to random trials, causing subjects to fail goals and reflect on their performance. Using computational methods, we identified two internal states, indicating that subjects kept track of past errors and perturbations, that predicted variability in reaction times and speed errors. These states granted access to latent information indicative of how subjects strategize learning from trial history, impacting their overall performance. We further found that large-scale brain networks differentially encoded these internal states. The dorsal attention network encoded past errors in frequencies above 100 Hz, suggesting a role in modulating attention based on tracking recent performance in working memory. The default network encoded past perturbations in frequencies below 15 Hz, suggesting a role in achieving robust performance in an uncertain environment. Moreover, these networks more strongly encoded internal states and were more functionally connected in higher performing subjects, whose learning strategy was to respond by countering with behavior that opposed accumulating error. Taken together, our findings suggest large-scale brain networks as a neural basis of strategy. These networks regulate movement variability, through internal states, to improve motor performance.Key pointsMovement variability is a purposeful process conjured up by the brain to enable adaptation and learning, both of which are necessary for survival.The culmination of recent experiences—collectively referred to as internal states—have been implicated in variability during motor and behavioral tasks.To investigate the utility and neural basis of internal states during motor control, we estimated two latent internal states using state-space representation that modeled motor behavior during a goal-directed center-out reaching task in humans with simultaneous whole-brain recordings from intracranial depth electrodes.We show that including these states—based on error and environment uncertainty—improves the predictability of subject-specific variable motor behavior and reveals latent information related to task performance and learning strategies where top performers counter error scaled by trial history while bottom performers maintain error tendencies.We further show that these states are encoded by the large-scale brain networks known as the dorsal attention network and default network in frequencies above 100 Hz and below 15 Hz but found neural differences between subjects where network activity closely modulates with states and exhibits stronger functional connectivity for top performers.Our findings suggest the involvement in large-scale brain networks as a neural basis of motor strategy that orchestrates movement variability to improve motor performance.</jats:list-item

Symmetry breaking and circular photogalvanic effect in epitaxial CdxHg1-xTe films

We report on the observation of symmetry breaking and the circular photogalvanic effect in CdxHg1-xTe alloys. We demonstrate that irradiation of bulk epitaxial films with circularly polarized terahertz radiation leads to the circular photogalvanic effect (CPGE) yielding a photocurrent whose direction reverses upon switching the photon helicity. This effect is forbidden in bulk zinc-blende crystals by symmetry arguments; therefore, its observation indicates either the symmetry reduction of bulk material or that the photocurrent is excited in the topological surface states formed in a material with low cadmium concentration. We show that the bulk states play a crucial role because the CPGE was also clearly detected in samples with noninverted band structure. We suggest that strain is a reason for the symmetry reduction. We develop a theory of the CPGE showing that the photocurrent results from the quantum interference of different pathways contributing to the free-carrier absorption (Drude-like) of monochromatic radiation

Le compartiment sauvage de la carotte en France : des ressources génétiques importantes et pourtant méconnues

La France est considérée comme centre secondaire de diversification de la carotte, du fait de l’activité importante de sélection (par des maraîchers ou semenciers), ce qui justifie les actions de conservation et connaissance des variétés anciennes menées par le réseau de ressources génétiques « Carotte et autres Daucus ». Par contre, le compartiment sauvage est méconnu et sous-exploité, alors qu’il s’agit d’une espèce pour laquelle de nombreuses populations existent sur le territoire français, avec une situation très contrastée. Si la carotte sauvage D. carota spp carota n’est pas en danger, d’autres sous espèces sont protégées (ssp gadecaei) ou menacées du fait de la dégradation de leur milieux naturels notamment en zone littorale ou de possibles introgressions avec la sous-espèce carota. Le travail présenté porte donc sur : i/ la sauvegarde et la mise à disposition des ressources génétiques sauvages, à travers l’inventaire de populations in situ et la constitution de collections ex-situ ; ii/ l’approfondissement de la connaissance et de l’identification taxonomique des sous-espèces sauvages ; iii/ la connaissance de la diversité au sein du compartiment sauvage (marqueurs SSR et données écologiques) ; et iv/ l’évaluation des ressources génétiques sauvages de carotte pour permettre leur exploitation (fertilité, croisements avec le compartiment cultivé, tolérance à différents bioagresseurs). Ce programme fait l’objet du soutien d’un contrat de branche du ministère de l’agriculture et implique les membres du réseau « Carotte et autres Daucus ».

Characterization of Geographical and Meteorological Parameters

[EN]This chapter is devoted to the introduction of some geographical and meteorological information involved in the numerical modeling of wind fields and solar radiation. First, a brief description of the topographical data given by a Digital Elevation Model and Land Cover databases is provided. In particular, the Information System of Land Cover of Spain (SIOSE) is considered. The study is focused on the roughness length and the displacement height parameters that appear in the logarithmic wind profile, as well as in the albedo related to solar radiation computation. An extended literature review and characterization of both parameters are reported. Next, the concept of atmospheric stability is introduced from the Monin–Obukhov similarity theory to the recent revision of Zilitinkevich of the Neutral and Stable Boundary Layers (SBL). The latter considers the effect of the free-flow static stability and baroclinicity on the turbulent transport of momentum and of the Convective Boundary Layers (CBL), more precisely, the scalars in the boundary layer, as well as the model of turbulent entrainment

Medical treatment of renal cancer: new horizons.

Renal cell carcinoma (RCC) makes up 2-3% of adult cancers. The introduction of tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin inhibitors in the mid-2000s radically changed the management of RCC. These targeted treatments superseded immunotherapy with interleukin-2 and interferon. The pendulum now appears to be shifting back towards immunotherapy, with the evidence of prolonged overall survival of patients with metastatic RCC on treatment with the anti-programmed cell death 1 ligand monoclonal antibody, nivolumab. Clinical prognostic criteria aid prediction of relapse risk for resected localised disease. Unfortunately, for patients at high risk of relapse, no adjuvant treatment has yet shown benefit, although further trials are yet to report. Clinical prognostic models also have a role in the management of advanced disease; now there is a pressing need for predictive biomarkers to direct therapy. Treatment selection for metastatic disease is currently based on histology, prognostic group and patient preference based on side effect profile. In this article, we review the current medical and surgical management of localised, oligometastatic and advanced RCC, including side effect management and the evidence base for management of poor-risk and non-clear cell disease. We discuss recent results from clinical trials and how these are likely to shape future practice and a renaissance of immunotherapy for renal cell cancer

The Bolund Experiment, Part I: Flow Over a Steep, Three-Dimensional Hill

We present an analysis of data from a measurement campaign performed at the Bolund peninsula in Denmark in the winter of 2007–2008. Bolund is a small isolated hill exhibiting a significantly steep escarpment in the main wind direction. The physical shape of Bolund represents, in a scaled-down form, a typical wind turbine site in complex terrain. Because of its small size the effect of atmospheric stratification can be neglected, which makes the Bolund experiment ideal for the validation of neutral flow models and hence model scenarios most relevant to wind energy. We have carefully investigated the upstream conditions. With a 7-km fetch over water, the incoming flow is characterized as flow over flat terrain with a local roughness height based on the surface momentum flux. The nearly perfect upstream conditions are important in forming a meaningful quantitative description of the flow over the Bolund hill. Depending on the wind direction, we find a maximum speed-up of 30% at the hill top accompanied by a maximum 300% enhancement of turbulence intensity. A closer inspection reveals transient behaviour with recirculation zones. From the wind energy context, this implies that the best site for erecting a turbine based on resource constraints unfortunately also imposes a penalty of high dynamic loads. On the lee side of Bolund, recirculation occurs with the turbulence intensity remaining significantly enhanced even at one hill length downstream. Its transient behaviour and many recirculation zones place Bolund in a category in which the linear flow theory is not applicable