The pancreatic beta cell surface proteome

The pancreatic beta cell is responsible for maintaining normoglycaemia by secreting an appropriate amount of insulin according to blood glucose levels. The accurate sensing of the beta cell extracellular environment is therefore crucial to this endocrine function and is transmitted via its cell surface proteome. Various surface proteins that mediate or affect beta cell endocrine function have been identified, including growth factor and cytokine receptors, transporters, ion channels and proteases, attributing important roles to surface proteins in the adaptive behaviour of beta cells in response to acute and chronic environmental changes. However, the largely unknown composition of the beta cell surface proteome is likely to harbour yet more information about these mechanisms and provide novel points of therapeutic intervention and diagnostic tools. This article will provide an overview of the functional complexity of the beta cell surface proteome and selected surface proteins, outline the mechanisms by which their activity may be modulated, discuss the methods and challenges of comprehensively mapping and studying the beta cell surface proteome, and address the potential of this interesting subproteome for diagnostic and therapeutic applications in human diseas

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Cognitive and emotional empathy in individuals at clinical high risk of psychosis

Background Impairments of social cognition are considered core features of schizophrenia and are established predictors of social functioning. However, affective aspects of social cognition including empathy have far less been studied than its cognitive dimensions. The role of empathy in the development of schizophrenia remains largely elusive. Methods Emotional and cognitive empathy were investigated in large sample of 120 individuals at Clinical High Risk of Psychosis (CHR-P) and compared with 50 patients with schizophrenia and 50 healthy controls. A behavioral empathy assessment, the Multifaceted Empathy Test, was implemented, and associations of empathy with cognition, social functioning, and symptoms were determined. Results Our findings demonstrated significant reductions of emotional empathy in individuals at CHR-P, while cognitive empathy appeared intact. Only individuals with schizophrenia showed significantly reduced scores of cognitive empathy compared to healthy controls and individuals at CHR-P. Individuals at CHR-P were characterized by significantly lower scores of emotional empathy and unspecific arousal for both positive and negative affective valences compared to matched healthy controls and patients with schizophrenia. Results also indicated a correlation of lower scores of emotional empathy and arousal with higher scores of prodromal symptoms. Conclusion Findings suggest that the tendency to 'feel with' an interaction partner is reduced in individuals at CHR-P. Altered emotional reactivity may represent an additional, early vulnerability marker, even if cognitive mentalizing is grossly unimpaired in the prodromal stage. Different mechanisms might contribute to reductions of cognitive and emotional empathy in different stages of non-affective psychotic disorders and should be further explored

The pancreatic beta cell surface proteome

The pancreatic beta cell is responsible for maintaining normoglycaemia by secreting an appropriate amount of insulin according to blood glucose levels. The accurate sensing of the beta cell extracellular environment is therefore crucial to this endocrine function and is transmitted via its cell surface proteome. Various surface proteins that mediate or affect beta cell endocrine function have been identified, including growth factor and cytokine receptors, transporters, ion channels and proteases, attributing important roles to surface proteins in the adaptive behaviour of beta cells in response to acute and chronic environmental changes. However, the largely unknown composition of the beta cell surface proteome is likely to harbour yet more information about these mechanisms and provide novel points of therapeutic intervention and diagnostic tools. This article will provide an overview of the functional complexity of the beta cell surface proteome and selected surface proteins, outline the mechanisms by which their activity may be modulated, discuss the methods and challenges of comprehensively mapping and studying the beta cell surface proteome, and address the potential of this interesting subproteome for diagnostic and therapeutic applications in human disease

Anomalous Diffusion Of Light In 1D Random Dimer Waveguide Arrays

We experimentally demonstrate super-diffusion and the delocalization-localization phase transition in a random dimer structure. The system is implemented using weakly-coupled optical waveguides. © 2013 Optical Society of America

Observation Of Anomalous Diffusion In A 1D Optical Random Dimer

It is a popular belief that in one-dimensional (1D) systems the presence of any amount of disorder would lead to localized eigenstates - the so-called Anderson localization [1]. In contrast, a few theoretical counter-examples show that an amount of correlations in a disordered potential can lead to long-range transport. The prototypical case is the Random Dimer Model (RDM) [2] where in the context of a tight-binding Hamiltonian pairs of adjacent energy levels are assigned at random, leading to two-site correlations in an otherwise random lattice. © 2013 IEEE

Experimental observation of superdiffusive transport in random dimer lattices

We experimentally observe anomalous wavepacket evolution in a realization of a one-dimensional finite binary Anderson model in the presence of short-range correlations. To this end, we employ weakly-coupled optical waveguides with propagation constants epsilon(1) and epsilon(2). The correlations enforce the creation of dimers, i.e. two adjacent waveguides with the same epsilon, randomly placed along the lattice. A transition from a ballistic to a superdiffusive wavepacket expansion and, eventually, to localization is observed as the contrast between the two propagation constants increases

Experimental observation of superdiffusive transport in random dimer lattices

We experimentally observe anomalous wavepacket evolution in a realization of a one-dimensional finite binary Anderson model in the presence of short-range correlations. To this end, we employ weakly-coupled optical waveguides with propagation constants epsilon(1) and epsilon(2). The correlations enforce the creation of dimers, i.e. two adjacent waveguides with the same epsilon, randomly placed along the lattice. A transition from a ballistic to a superdiffusive wavepacket expansion and, eventually, to localization is observed as the contrast between the two propagation constants increases

Anomalous diffusion of light in 1D random dimer waveguide arrays

We experimentally demonstrate super-diffusion and the delocalization-localization phase transition in a random dimer structure. The system is implemented using weakly-coupled optical waveguides