Novel role for the LKB1 pathway in controlling monocarboxylate fuel transporters

A question preoccupying many researchers is how signal transduction pathways control metabolic processes and energy production. A study by Jang et al. (Jang, C., G. Lee, and J. Chung. 2008. J. Cell Biol. 183:11–17) provides evidence that in Drosophila melanogaster a signaling network controlled by the LKB1 tumor suppressor regulates trafficking of an Sln/dMCT1 monocarboxylate transporter to the plasma membrane. This enables cells to import additional energy sources such as lactate and butyrate, enhancing the repertoire of fuels they can use to power vital activities

Optimized Jastrow-Slater wave functions for ground and excited states: Application to the lowest states of ethene

A quantum Monte Carlo method is presented for determining multi-determinantal Jastrow-Slater wave functions for which the energy is stationary with respect to the simultaneous optimization of orbitals and configuration interaction coefficients. The approach is within the framework of the so-called energy fluctuation potential method which minimizes the energy in an iterative fashion based on Monte Carlo sampling and a fitting of the local energy fluctuations. The optimization of the orbitals is combined with the optimization of the configuration interaction coefficients through the use of additional single excitations to a set of external orbitals. A new set of orbitals is then obtained from the natural orbitals of this enlarged configuration interaction expansion. For excited states, the approach is extended to treat the average of several states within the same irreducible representation of the pointgroup of the molecule. The relationship of our optimization method with the stochastic reconfiguration technique by Sorella et al. is examined. Finally, the performance of our approach is illustrated with the lowest states of ethene, in particular with the difficult case of the singlet 1B_1u state.Comment: 12 pages, 2 figure

Interfacial contribution to the dielectric response in semiconducting LaBiMn4/3Co2/3O6

Impedance measurements have been performed on a sintered polycrystalline sample of the perovskite LaBiMn4/3Co2/3O6. Colossal dielectric permittivity often is measured in this class of semiconducting materials as a result of extrinsic factors. Our results show that a large offset in the capacitance, measured on a series of samples with different thickness, is due to the interfacial polarization. This contribution then can be removed from the data, creating a general procedure for dielectric measurements in semiconducting samples.Comment: 13 pages, 4 figure

Progressive modularization: Reframing our understanding of typical and atypical language development

The ability to acquire language is a critical part of human development. Yet there is no consensus on how the skill emerges in early development. Does it constitute an innately-specified, language-processing module or is it acquired progressively? One of Annette Karmiloff-Smith’s (1938–2016) key contributions to developmental science addresses this very question. Karmiloff-Smith persistently maintained that the process of development itself constitutes a crucial factor in phenotypic outcomes. She proposed that cognitive modules gradually emerge through a developmental process – ‘progressive modularization’. This concept helped to advance the field beyond the stale nature–nurture controversy. It enabled language researchers to develop more nuanced transactional frameworks that take seriously the integration of genes and environment. In homage to Karmiloff-Smith, the current article describes the importance of her work to the field of developmental psychology and language research. It examines how the concept of progressive modularization could be applied to language development as well as how it has greatly advanced our understanding of language difficulties in children with neurodevelopmental disorders. Finally, it discusses how Karmiloff-Smith’s approach is inspiring current and future research

Alleviation of the Fermion-sign problem by optimization of many-body wave functions

We present a simple, robust and highly efficient method for optimizing all parameters of many-body wave functions in quantum Monte Carlo calculations, applicable to continuum systems and lattice models. Based on a strong zero-variance principle, diagonalization of the Hamiltonian matrix in the space spanned by the wav e function and its derivatives determines the optimal parameters. It systematically reduces the fixed-node error, as demonstrated by the calculation of the binding energy of the small but challenging C$_2$ molecule to the experimental accuracy of 0.02 eV

Competing mechanisms of stress-assisted diffusivity and stretch-activated currents in cardiac electromechanics

We numerically investigate the role of mechanical stress in modifying the conductivity properties of the cardiac tissue and its impact in computational models for cardiac electromechanics. We follow a theoretical framework recently proposed in [Cherubini, Filippi, Gizzi, Ruiz-Baier, JTB 2017], in the context of general reaction-diffusion-mechanics systems using multiphysics continuum mechanics and finite elasticity. In the present study, the adapted models are compared against preliminary experimental data of pig right ventricle fluorescence optical mapping. These data contribute to the characterization of the observed inhomogeneity and anisotropy properties that result from mechanical deformation. Our novel approach simultaneously incorporates two mechanisms for mechano-electric feedback (MEF): stretch-activated currents (SAC) and stress-assisted diffusion (SAD); and we also identify their influence into the nonlinear spatiotemporal dynamics. It is found that i) only specific combinations of the two MEF effects allow proper conduction velocity measurement; ii) expected heterogeneities and anisotropies are obtained via the novel stress-assisted diffusion mechanisms; iii) spiral wave meandering and drifting is highly mediated by the applied mechanical loading. We provide an analysis of the intrinsic structure of the nonlinear coupling using computational tests, conducted using a finite element method. In particular, we compare static and dynamic deformation regimes in the onset of cardiac arrhythmias and address other potential biomedical applications

Improving human development through design education: the Osasco Design Studio (SP, Brazil) 2006-2009

The Research and Documentation Centre in Technology, Architecture and Town in Developing Countries (CRD-PVS) at Politecnico di Torino promotes research addressing habitat improvement under conditions that can be regarded as borderline in terms of climate or social emergence. It coordinates the post-graduate course in Habitat, Technology and Development, which trains architects and engineers to be capable of working with an integrated approach to design in different cultural, political and economic settings and identifying all available resources. Starting in academic year 2006/07, thanks to a framework agreement with the Municipality of Osasco (San Paolo, Brazil), the CRD-PVS organizes design workshops as part of the post-graduate course

Planning for real: ICT as a tool in urban regeneration

One of the major worldwide issues in the informal settlements has been spotted in the absence or weakness of community awareness. The problem can be analysed through different perspectives, related to security and social behaviours, environmental care and energy consumption. In such a complex scenario, it has been considered that one of the biggest difficulties for the planning units of municipalities in metropolitan areas, who deal with illegal and marginal settlements upgrading projects, is to face with frictions and resistances in some degree to their decisions, projects and actions. In order to increase the awareness of citizenship, ICT can be considered as a revolutionary support in this context. Low cost and friendly tools could help to upgrade the educational level of low incoming people, opening the communities and increasing the sense of belonging to a urban context as well as a neighbourhood. Digital democracy through digital inclusion and e-learning can be aimed in order to let citizen know, participate, share, improve or criticise projects and actions