Damage to the prefrontal cortex increases utilitarian moral judgements

The psychological and neurobiological processes underlying moral judgement have been the focus of many recent empirical studies1–11. Of central interest is whether emotions play a causal role in moral judgement, and, in parallel, how emotion-related areas of the brain contribute to moral judgement. Here we show that six patients with focal bilateral damage to the ventromedial prefrontal cortex (VMPC), a brain region necessary for the normal generation of emotions and, in particular, social emotions12–14, produce an abnor- mally ‘utilitarian’ pattern of judgements on moral dilemmas that pit compelling considerations of aggregate welfare against highly emotionally aversive behaviours (for example, having to sacrifice one person’s life to save a number of other lives)7,8. In contrast, the VMPC patients’ judgements were normal in other classes of moral dilemmas. These findings indicate that, for a selective set of moral dilemmas, the VMPC is critical for normal judgements of right and wrong. The findings support a necessary role for emotion in the generation of those judgements

Parameter estimators of random intersection graphs with thinned communities

This paper studies a statistical network model generated by a large number of randomly sized overlapping communities, where any pair of nodes sharing a community is linked with probability $q$ via the community. In the special case with $q=1$ the model reduces to a random intersection graph which is known to generate high levels of transitivity also in the sparse context. The parameter $q$ adds a degree of freedom and leads to a parsimonious and analytically tractable network model with tunable density, transitivity, and degree fluctuations. We prove that the parameters of this model can be consistently estimated in the large and sparse limiting regime using moment estimators based on partially observed densities of links, 2-stars, and triangles.Comment: 15 page

Adjustment of the Arabidopsis circadian oscillator by sugar signalling dictates the regulation of starch metabolism.

Arabidopsis plants store part of the carbon fixed by photosynthesis as starch to sustain growth at night. Two competing hypotheses have been proposed to explain this diel starch turnover based on either the measurement of starch abundance with respect to circadian time, or the sensing of sugars to feedback to the circadian oscillator to dynamically adjust the timing of starch turnover. We report a phase oscillator model that permitted derivation of the ideal responses of the circadian regulation of starch breakdown to maintain sucrose homeostasis. Testing the model predictions using a sugar-unresponsive mutant of Arabidopsis demonstrated that the dynamics of starch turnover arise from the circadian clock measuring and responding to the rate of change of cellular sucrose. Our theory and experiments suggest that starch turnover is controlled by the circadian clock acting as a dynamic homeostat responding to sucrose signals to maintain carbon homeostasis

Soliton pair dynamics in patterned ferromagnetic ellipses

Confinement alters the energy landscape of nanoscale magnets, leading to the appearance of unusual magnetic states, such as vortices, for example. Many basic questions concerning dynamical and interaction effects remain unanswered, and nanomagnets are convenient model systems for studying these fundamental physical phenomena. A single vortex in restricted geometry, also known as a non-localized soliton, possesses a characteristic translational excitation mode that corresponds to spiral-like motion of the vortex core around its equilibrium position. Here, we investigate, by a microwave reflection technique, the dynamics of magnetic soliton pairs confined in lithographically defined, ferromagnetic Permalloy ellipses. Through a comparison with micromagnetic simulations, the observed strong resonances in the subgigahertz frequency range can be assigned to the translational modes of vortex pairs with parallel or antiparallel core polarizations. Vortex polarizations play a negligible role in the static interaction between two vortices, but their effect dominates the dynamics.Comment: supplemental movies on http://www.nature.com/nphys/journal/v1/n3/suppinfo/nphys173_S1.htm

Mixed Candida albicans strain populations in colonized and infected mucosal tissues

Multilocus sequence typing of six Candida albicans colonies from primary isolation plates revealed instances of colony-to-colony microvariation and carriage of two strain types in single oropharyngeal and vaginal samples. Higher rates of colony variation in commensal samples suggest selection of types from mixed populations either in the shift to pathogenicity or the response to antifungal treatment

Sucrose and Ethylene Signaling Interact to Modulate the Circadian Clock.

Circadian clocks drive rhythmic physiology and metabolism to optimize plant growth and performance under daily environmental fluctuations caused by the rotation of the planet. Photosynthesis is a key metabolic process that must be appropriately timed to the light-dark cycle. The circadian clock contributes to the regulation of photosynthesis, and in turn the daily accumulation of sugars from photosynthesis also feeds back to regulate the circadian oscillator. We have previously shown that GIGANTEA (GI) is required to sustain Suc-dependent circadian rhythms in darkness. The mechanism by which Suc affects the circadian oscillator in a GI-dependent manner was unknown. Here, we identify that Suc sustains rhythms in the dark by stabilizing GI protein, dependent on the F-box protein ZEITLUPE, and implicate CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), a negative regulator of ethylene signaling. Our identification of a role for CTR1 in the response to Suc prompted a reinvestigation of the effects of ethylene on the circadian oscillator. We demonstrate that ethylene shortens the circadian period, conditional on the effects of Suc and requiring GI These findings reveal that Suc affects the stability of circadian oscillator proteins and can mask the effects of ethylene on the circadian system, identifying novel molecular pathways for input of sugar to the Arabidopsis (Arabidopsis thaliana) circadian network.This research was supported by the BBSRC (BB/H006826/1 and BB/L021188/1