Surface-induced charge state conversion of nitrogen-vacancy defects in nanodiamonds

We present a study of the charge state conversion of single nitrogen-vacancy (NV) defects hosted in nanodiamonds (NDs). We first show that the proportion of negatively-charged NV$^{-}$ defects, with respect to its neutral counterpart NV$^{0}$, decreases with the size of the ND. We then propose a simple model based on a layer of electron traps located at the ND surface which is in good agreement with the recorded statistics. By using thermal oxidation to remove the shell of amorphous carbon around the NDs, we demonstrate a significant increase of the proportion of NV$^{-}$ defects in 10-nm NDs. These results are invaluable for further understanding, control and use of the unique properties of negatively-charged NV defects in diamondComment: 6 pages, 4 figure

The influence of controlled processes reasoning with Theory of Mind (ToM) in children with and without intellectual disabilities

La capacidad o mecanismo tácito de atribuir estados mentales a los otros y a uno mismo, con el objeto de anticipar, comprender y predecir la conducta, es conocida como Teoría de la Mente (ToM). Parte de la discusión se centra en comprender si este razonamiento es un proceso independiente o subordinado a los procesos ejecutivos de control consciente. En esta investigación se analiza el efecto de las funciones ejecutivas de control consciente en tareas de razonamiento con ToM, en niños con y sin discapacidad intelectual. La muestra la constituyen 30 niños con discapacidad intelectual y 20 niños sin discapacidad intelectual. Se hipotetizó que la habilidad para responder las preguntas de control, una operacionalización de las funciones ejecutivas de control consciente, se asocia más a las tareas de segundo orden que a las de primer orden, ya que estas requieren mayor carga representacional. Los resultados obtenidos, sugieren que los procesos de control consciente no sólo se asocian a las tareas que requieren una mayor carga representacional, sino a todas las tareas que requieren razonar con estados mentales, sean ellos de primer o segundo orden

La influencia de los procesos controlados en el razonamiento con Teoría de la Mente (ToM) en niños con y sin discapacidad intelectual

La capacidad o mecanismo tácito de atribuir estados mentales a los otros y a uno mismo, con el objeto de anticipar, comprender y predecir la conducta, es conocida como Teoría de la Mente (ToM). Parte de la discusión se centra en comprender si este razonamiento es un proceso independiente o subordinado a los procesos ejecutivos de control consciente. En esta investigación se analiza el efecto de las funciones ejecutivas de control consciente en tareas de razonamiento con ToM, en niños con y sin discapacidad intelectual. La muestra la constituyen 30 niños con discapacidad intelectual y 20 niños sin discapacidad intelectual. Se hipotetizó que la habilidad para responder las preguntas de control, una operacionalización de las funciones ejecutivas de control consciente, se asocia más a las tareas de segundo orden que a las de primer orden, ya que estas requieren mayor carga representacional. Los resultados obtenidos, sugieren que los procesos de control consciente no sólo se asocian a las tareas que requieren una mayor carga representacional, sino a todas las tareas que requieren razonar con estados mentales, sean ellos de primer o segundo orden

Life satisfaction in coastal Kenya and Mozambique reflects culture, gendered relationships and security of basic needs: Implications for ecosystem services

This is the final version. Available from Elsevier via the DOI in this record. Data availability: Data are published in https://reshare.ukdataservice.ac.ukLife satisfaction is both a desirable ‘end’ for sustainable development, and a means to understand the priorities, and behaviour of people towards local ecosystems. Ecosystem-services research on life satisfaction has focused on cultural services in wealthy, Western contexts, although ecosystem services are essential for poor people's livelihoods in the Global South. We examined reported life satisfaction from a survey of over 2000 people in rural and urban settings of coastal Kenya and Mozambique. We coded respondents’ open-ended reasons for their reported satisfaction, and used multiple correspondence analysis to explore the characteristics of people who mentioned different reasons. We tested associations between satisfaction and the meeting of basic needs and income, with binary logistic regression, accounting for site and gender. Life satisfaction was lower in Kenya, for men, and in the most urbanised site. Respondents explained high, and low, satisfaction in terms of social relationships, basic needs, money and employment. They rarely mentioned the ecosystem services and related livelihoods that underpin those, suggesting an instrumental relation to nature. Meeting basic needs, including economic security better predicted satisfaction than household income. Life satisfaction reflected material differences in people's lives but also different evaluative criteria and national cultures. For example, family reasons more commonly explained women's satisfaction, while money was more important for urban-dwelling men. We propose that the holistic perspective offered by life-satisfaction research can inform environmental management alongside more focused ecosystem-service research. For example, our results suggest that a) interventions should recognise immediate needs and social relationships, b) the role of ecosystem services for subjective wellbeing varies by local culture and individual identities and c) secure and fair access to ecosystem services may support life satisfaction better than high incomes that are insecure or inequitably distributed.Economic and Social Research Council (ESRC)Department for International Development (DFID)Natural Environment Research Council (NERC

Feature integration in natural language concepts

Two experiments measured the joint influence of three key sets of semantic features on the frequency with which artifacts (Experiment 1) or plants and creatures (Experiment 2) were categorized in familiar categories. For artifacts, current function outweighed both originally intended function and current appearance. For biological kinds, appearance and behavior, an inner biological function, and appearance and behavior of offspring all had similarly strong effects on categorization. The data were analyzed to determine whether an independent cue model or an interactive model best accounted for how the effects of the three feature sets combined. Feature integration was found to be additive for artifacts but interactive for biological kinds. In keeping with this, membership in contrasting artifact categories tended to be superadditive, indicating overlapping categories, whereas for biological kinds, it was subadditive, indicating conceptual gaps between categories. It is argued that the results underline a key domain difference between artifact and biological concepts

Fibrosis progression under maintenance interferon in hepatitis C is better detected by blood test than liver morphometry

Summary.  We evaluated whether quantitative measurements of liver fibrosis with recently developed diagnostics outperform histological staging in detecting natural or interferon-induced changes. We compared Metavir staging, morphometry (area and fractal dimension) and six blood tests in 157 patients with chronic hepatitis C from two trials testing maintenance interferon for 96 weeks. Paired liver biopsies and blood tests were available for 101 patients, and there was a significant improvement in Metavir activity and a significant increase in blood tests reflecting fibrosis quantity in patients treated with interferon when compared with controls – all per cent changes in histological fibrosis measures were significantly increased in F1 vs F2–4 stages only in the interferon group. For the whole population studied between weeks 0 and 96, there was significant progression only in the area of fibrosis (AOF) (P = 0.026), FibroMeter (P = 0.020) and CirrhoMeter (P = 0.003). With regards to dynamic reproducibility, agreement was good (ric ≥ 0.72) only for Metavir fibrosis score, FibroMeter and CirrhoMeter. The per cent change in AOF was significantly higher than that of fractal dimension (P = 0.003) or Metavir fibrosis score (P = 0.015). CirrhoMeter was the only blood test with a change significantly higher than that of AOF (P = 0.039). AOF and two blood tests, reflecting fibrosis quantity, have high sensitivity and/or reproducibility permitting the detection of a small progression in liver fibrosis over two years. A blood test reflecting fibrosis quantity is more sensitive and reproducible than morphometry. The study also shows that maintenance interferon does not improve fibrosis, whatever its stage

Adaptive Movement Compensation for In Vivo Imaging of Fast Cellular Dynamics within a Moving Tissue

In vivo non-linear optical microscopy has been essential to advance our knowledge of how intact biological systems work. It has been particularly enabling to decipher fast spatiotemporal cellular dynamics in neural networks. The power of the technique stems from its optical sectioning capability that in turn also limits its application to essentially immobile tissue. Only tissue not affected by movement or in which movement can be physically constrained can be imaged fast enough to conduct functional studies at high temporal resolution. Here, we show dynamic two-photon Ca2+ imaging in the spinal cord of a living rat at millisecond time scale, free of motion artifacts using an optical stabilization system. We describe a fast, non-contact adaptive movement compensation approach, applicable to rough and weakly reflective surfaces, allowing real-time functional imaging from intrinsically moving tissue in live animals. The strategy involves enslaving the position of the microscope objective to that of the tissue surface in real-time through optical monitoring and a closed feedback loop. The performance of the system allows for efficient image locking even in conditions of random or irregular movements

Hemodynamic Responses Evoked by Neuronal Stimulation via Channelrhodopsin-2 Can Be Independent of Intracortical Glutamatergic Synaptic Transmission

Maintenance of neuronal function depends on the delivery of oxygen and glucose through changes in blood flow that are linked to the level of ongoing neuronal and glial activity, yet the underlying mechanisms remain unclear. Using transgenic mice expressing the light-activated cation channel channelrhodopsin-2 in deep layer pyramidal neurons, we report that changes in intrinsic optical signals and blood flow can be evoked by activation of a subset of channelrhodopsin-2-expressing neurons in the sensorimotor cortex. We have combined imaging and pharmacology to examine the importance of glutamatergic synaptic transmission in this form of neurovascular coupling. Blockade of ionotropic glutamate receptors with the antagonists CNQX and MK801 significantly reduced forepaw-evoked hemodynamic responses, yet resulted in no significant reduction of channelrhodopsin-evoked hemodynamic responses, suggesting that stimulus-dependent coupling of neuronal activity to blood flow can be independent of local excitatory synaptic transmission. Together, these results indicate that channelrhodopsin-2 activation of sensorimotor excitatory neurons produces changes in intrinsic optical signals and blood flow that can occur under conditions where synaptic activation of neurons or other cells through ionotropic glutamate receptors would be blocked

Proving Resistance Against Invariant Attacks: How to Choose the Round Constants.

International audienceMany lightweight block ciphers apply a very simple key schedule in which the round keys only differ by addition of a round-specific constant. Generally, there is not much theory on how to choose appropriate constants. In fact, several of those schemes were recently broken using invariant attacks, i.e., invariant subspace or nonlinear invariant attacks. This work analyzes the resistance of such ciphers against invariant attacks and reveals the precise mathematical properties that render those attacks applicable. As a first practical consequence, we prove that some ciphers including Prince, Skinny-64 and Mantis 7 are not vulnerable to invariant attacks. Also, we show that the invariant factors of the linear layer have a major impact on the resistance against those attacks. Most notably, if the number of invariant factors of the linear layer is small (e.g., if its minimal polynomial has a high degree), we can easily find round constants which guarantee the resistance to all types of invariant attacks, independently of the choice of the S-box layer. We also explain how to construct optimal round constants for a given, but arbitrary, linear layer