INTÉRÊT DE L’UTILISATION DES SCORES DE RISQUES POLYGÉNIQUES DANS LE DÉPISTAGE DU CANCER DU SEIN ET LA MÉDECINE DE PRÉVENTION

editorial reviewedDespite screening programmes, numerous clinical studies and new breast imaging techniques, breast cancer incidence for women continues to rise. The arrival of predictive and personalized medicine could clearly redefine our screening recommendations. One promising approach to improving screening would be to use tools to predict the risk of developing breast cancer, including polygenic risk scores (PRS). This approach will enable us to offer women risk-based screening by adapting the frequency, type and age of screening. This article reviews some definitions of the PRS and breast cancer screening. We also explain the risk assessment models that have been developed and the various studies underway on personalized screening

Primary osteosarcoma of the breast : a case report

We report a rare case of primary osteosarcoma of the breast in a patient who presented a calcified fibroadenoma one year before the appearance of the malignant lesion. We describe the follow‐up of the patient and the discovery of a similar osteosarcoma in the other breast one year later

Assessing the effectiveness of the Marine Stewardship Council certification in southern countries

© 2016 Julie CrevecoeurThe MSC certification scheme is one of the most adopted eco-labelling non profit market schemes in the world, accounting for 12% of global fisheries. It has not been successful in developing Southern countries which only account for 4% of its total certified fisheries. Literature is reviewed based on Northern researchers and literature from scientific, economic, development, sustainability and political based journals studying the impacts of eco-labelling and MSC related schemes in Southern countries. The consensus of opinion is that data deficiencies of Southern fisheries, combined with high costs and weak management structures provide barriers for adoption in these regions. This is exacerbated by the lack of market incentives, which do not cater to Southern fishery needs and markets

Expression of SV2 isoforms during rodent brain development

BACKGROUND: SV2A, SV2B and SV2C are synaptic vesicle proteins that are structurally related to members of the major facilitator superfamily (MFS). The function and transported substrate of the SV2 proteins is not clearly defined although they are linked to neurotransmitters release in a presynaptic calcium concentration-dependent manner. SV2A and SV2B exhibit broad expression in the central nervous system while SV2C appears to be more restricted in defined areas such as striatum. SV2A knockout mice start to display generalized seizures at a late developmental stage, around post-natal day 7 (P7), and die around P15. More recently, SV2A was demonstrated to be the molecular target of levetiracetam, an approved anti-epileptic drug (AED). The purpose of this work was to precisely analyze and quantify the SV2A, SV2B and SV2C expression during brain development to understand the contribution of these proteins in brain development and their impact on epileptic seizures. RESULTS: First, we systematically analyzed by immunohistofluorescence, the SV2A, SV2B and SV2C expression during mouse brain development, from embryonic day 12 (E12) to P30. This semi-quantitative approach suggests a modulation of SV2A and SV2B expression in hippocampus around P7. This is the reason why we used various quantitative approaches (laser microdissection of whole hippocampus followed by qRT-PCR and western blot analysis) indicating that SV2A and SV2B expression increased between P5 and P7 and remained stable between P7 and P10. Moreover, the increase of SV2A expression in the hippocampus at P7 was mainly observed in the CA1 region while SV2B expression in this region remains stable. CONCLUSIONS: The observed alterations of SV2A expression in hippocampus are consistent with the appearance of seizures in SV2A−/− animals at early postnatal age and the hypothesis that SV2A absence favors epileptic seizures around P7

Reward boosts reinforcement-based motor learning

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Impact of reinforcement on action selection, initiation and execution during motor skill learning

The ability to learn motor skills is a fundamental feature of human behavior, which relies both on sensory and on reinforcement feedbacks (i.e., reward and punishment, Galea et al. 2015, Nat Neurosci). How such reinforcements lead to improved performance during motor skill learning remains an open question. In fact, skill learning can result from improvements at several levels of control, including action selection, initiation or execution. Here, we tested the impact of reinforcement on these different levels during motor skill learning. After 2 short practice blocks, subjects performed 10 blocks (360 trials in total) of a modified version of a force-tracking task (Steel et al., 2016, Sci Rep). Each trial started with a cursor appearing at the bottom of the screen and subjects were asked to squeeze a pinch-grip sensor to bring the cursor at the center of a fixed target and maintain it there for the rest of the trial. To reach the target, subjects had to exert a force (TargetForce) corresponding to 10 % of the individual maximal voluntary contraction. On most trials, the cursor disappeared shortly after the beginning of the trial. Hence, subjects had to learn to approximate the TargetForce in the absence of visual cursor. A trial was classified as successful if the mean of the difference between the actual force and the TargetForce was under an individualized threshold. At the end of each trial, subjects received a reinforcement feedback based on their performance (i.e., Success or Failure). In this task, success depended on force control at the level of action selection (i.e., ForceSel; the closer the mean of the selected force was to TargetForce, the higher the chances of success), at the level of initiation (i.e., the faster the onset [ForceStart] and the steeper the rate [ForceRate] of force production, the better) and execution (i.e., ForceExe; the lower the force variability during the tonic phase, the better). Moreover, we analyzed the evolution of the different force variables at the three levels of control, as well as the impact of reinforcement (i.e., Success or Failure) on performance in the next trial across training. As expected, the proportion of successful trials increased over training, indicating that subjects learned the motor skill. Moreover, we found that skill learning occurred at the level of action initiation (earlier ForceStart and steeper ForceRate) and execution (reduced ForceExe) but not at the level of action selection (no change in ForceSel). Interestingly, subjects improved at all levels of control in trials following a Failure, while they exhibited the opposite pattern following a Success. However, importantly, this effect of reinforcement changed over the course of learning. In fact, the beneficial effect of Failure increased across training while the detrimental effect of Success decreased. It remains to be determined whether these effects would vary with a reinforcement involving an actual monetary loss or gain

Impact of reinforcement on action selection, initiation and execution during motor skill learning

The ability to learn motor skills is a fundamental feature of human behavior, which relies both on sensory and on reinforcement feedbacks (i.e., reward and punishment, (Izawa and Shadmehr, 2011; Galea et al., 2015; Vassiliadis et al., 2019). How such reinforcements lead to improved performance during motor skill learning remains an open question. In fact, skill learning can result from improvements at several levels of control, including action selection, initiation or execution. Here, we tested the impact of reinforcement on these different levels during motor skill learning (Chen et al., 2017) After 2 short practice blocks, subjects performed 10 blocks (360 trials in total) of a modified version of a force-tracking task (Abe et al., 2011; Steel et al., 2016, 2019). Each trial started with a cursor appearing at the bottom of the screen and subjects were asked to squeeze a pinch-grip sensor to bring the cursor at the center of a fixed target and maintain it there for the rest of the trial. To reach the target, subjects had to exert a force (TargetForce) corresponding to 10 % of the individual maximal voluntary contraction. On most trials, the cursor disappeared shortly after the beginning of the trial. Hence, subjects had to learn to approximate the TargetForce in the absence of visual cursor. A trial was classified as successful if the mean of the difference between the actual force and the TargetForce was under an individualized threshold. At the end of each trial, subjects received a reinforcement feedback based on their performance (i.e., Success or Failure). In this task, success depended on force control at the level of action selection (i.e., ForceSel; the closer the mean of the selected force was to TargetForce, the higher the chances of success), at the level of initiation (i.e., the faster the onset [ForceStart] and the steeper the rate [ForceRate] of force production, the better) and execution (i.e., ForceExe; the lower the force variability during the tonic phase, the better). Moreover, we analyzed the evolution of the different force variables at the three levels of control, as well as the impact of reinforcement (i.e., Success or Failure) on performance in the next trial across training. As expected, the proportion of successful trials increased over training, indicating that subjects learned the motor skill. Moreover, we found that skill learning occurred at the level of action selection (ForceSel closer to TargetForce), initiation (earlier ForceStart and steeper ForceRate) and execution (reduced ForceExe). Interestingly, subjects improved at all levels of control in trials following a Failure, while they exhibited the opposite pattern following a Success. However, importantly, this effect of reinforcement changed over the course of learning. In fact, the beneficial effect of Failure increased across training while the detrimental effect of Success decreased. It remains to be determined whether these effects would vary with a reinforcement involving an actual monetary loss or gain