The Value of Fighting Irreversible Demise by Softening the Irreversible Cost

We study a novel issue in the real-options-based technology innovation literature by means of double barrier contingent claims analysis.We show how much a ¯rm with the monopoly over a project is willing to spend in investment technology innovation that softens the irreversible cost of accessing the project before its irreversible demise.The answer depends on the project's characteristics and on the e®ectiveness demanded from technology innovation.Double barrier options;cost irreversibility;demise irreversibility;technology innovation

Les migraines: des gènes à l'environnement

Peer reviewe

Differential Responses of Human Regulatory T Cells (Treg) and Effector T Cells to Rapamycin

Background: The immunosuppressive drug rapamycin (RAPA) promotes the expansion of CD4+ CD25highFoxp3+ regulatory\ud T cells via mechanisms that remain unknown. Here, we studied expansion, IL-2R-c chain signaling, survival pathways and resistance to apoptosis in human Treg responding to RAPA.\ud Methodology/Principal Findings: CD4+CD25+ and CD4+CD25neg T cells were isolated from PBMC of normal controls (n = 21)\ud using AutoMACS. These T cell subsets were cultured in the presence of anti-CD3/CD28 antibodies and 1000 IU/mL IL-2 for 3 to 6 weeks. RAPA (1–100 nM) was added to half of the cultures. After harvest, the cell phenotype, signaling via the PI3K/ mTOR and STAT pathways, expression of survival proteins and Annexin V binding were determined and compared to values obtained with freshly-separated CD4+CD25high and CD4+CD25neg T cells. Suppressor function was tested in co-cultures with autologous CFSE-labeled CD4+CD25neg or CD8+CD25neg T-cell responders. The frequency and suppressor activity of Treg were increased after culture of CD4+CD25+ T cells in the presence of 1–100 nM RAPA (p,0.001). RAPA-expanded Treg were largely CD4+CD25highFoxp3+ cells and were resistant to apoptosis, while CD4+CD25neg T cells were sensitive. Only Treg upregulated anti-apoptotic and down-regulated pro-apoptotic proteins. Treg expressed higher levels of the PTEN protein than CD4+CD25neg cells. Activated Treg6RAPA preferentially phosphorylated STAT5 and STAT3 and did not utilize the PI3K/ mTOR pathway.\ud Conclusions/Significance: RAPA favors Treg expansion and survival by differentially regulating signaling, proliferation and sensitivity to apoptosis of human effector T cells and Treg after TCR/IL-2 activation

Social Influence on Risk Perception During Adolescence.

Adolescence is a period of life in which peer relationships become increasingly important. Adolescents have a greater likelihood of taking risks when they are with peers rather than alone. In this study, we investigated the development of social influence on risk perception from late childhood through adulthood. Five hundred and sixty-three participants rated the riskiness of everyday situations and were then informed about the ratings of a social-influence group (teenagers or adults) before rating each situation again. All age groups showed a significant social-influence effect, changing their risk ratings in the direction of the provided ratings; this social-influence effect decreased with age. Most age groups adjusted their ratings more to conform to the ratings of the adult social-influence group than to the ratings of the teenager social-influence group. Only young adolescents were more strongly influenced by the teenager social-influence group than they were by the adult social-influence group, which suggests that to early adolescents, the opinions of other teenagers about risk matter more than the opinions of adults

A trial of metoclopramide vs sumatriptan for the emergency department treatment of migraines.

Peer reviewe

Social and non-social relational reasoning in adolescence and adulthood

Reasoning during social interactions requires the individual manipulation of mental representations of one’s own traits and those of other people, as well as their joint consideration (relational integration). Research using non-social paradigms has linked relational integration to activity in the rostrolateral prefrontal cortex (RLPFC). Here, we investigated whether social reasoning is supported by the same general system or whether it additionally relies on regions of the social brain network, such as the medial prefrontal cortex (MPFC). We further assessed the development of social reasoning. In the social task, participants evaluated themselves or a friend, or compared themselves with their friend, on a series of traits. In the non-social task, participants evaluated their hometown or another town, or compared the two. In a behavioural study involving 325 participants (11-39 years), we found that integrating relations compared to performing single relational judgements improves during adolescence, both for social and non-social information. Thirty-nine female participants (10-31 years) took part in a neuroimaging study using a similar task. Activation of the relational integration network, including the RLPFC, was observed in the comparison condition of both the social and non-social tasks, while MPFC showed greater activation when participants processed social as opposed to non-social information across conditions. Developmentally, the right anterior insula showed greater activity in adolescents compared with adults during the comparison of non-social vs. social information. This study shows parallel recruitment of the social brain and the relational reasoning network during the relational integration of social information in adolescence and adulthood

Transcutaneous Vagus Nerve Stimulation (tVNS) for headache prophylaxis: initial experience

peer reviewe

Ageing effects around the glass and melting transitions in poly(dimethylsiloxane) visualized by resistance measurements

The process of ageing in rubbers requires monitoring over long periods (days to years). To do so in non-conducting rubbers, small amounts of carbon-black particles were dispersed in a fractal network through the rubber matrix, to make the rubber conducting without modifying its properties. Continuous monitoring of the resistance reveals the structural changes around the glass and melting transitions and especially details about the hysteresis and ageing processes. We illustrate the method for the semicrystalline polymer poly(dimethylsiloxane) (PDMS).Comment: 4 pages, 4 figure