Neuronal Mechanisms and Transformations Encoding Time-Varying Signals

Sensation in natural environments requires the analysis of time-varying signals. While previous work has uncovered how a signal’s temporal rate is represented by neurons in sensory cortex, in this issue of Neuron, new evidence from Gao et al. (2016) provides insights on the underlying mechanisms

Spectral shift function for operators with crossed magnetic and electric fields

We obtain a representation formula for the derivative of the spectral shift function $\xi(\lambda; B, \epsilon)$ related to the operators $H_0(B,\epsilon) = (D_x - By)^2 + D_y^2 + \epsilon x$ and $H(B, \epsilon) = H_0(B, \epsilon) + V(x,y), \: B > 0, \epsilon > 0$. We establish a limiting absorption principle for $H(B, \epsilon)$ and an estimate ${\mathcal O}(\epsilon^{n-2})$ for $\xi'(\lambda; B, \epsilon)$, provided $\lambda \notin \sigma(Q)$, where $Q = (D_x - By)^2 + D_y^2 + V(x,y).

Information systems, software engineering, and systems thinking: challenges and opportunities

This article traces past research on the application of the systems approach to information systems development within the disciplines of information systems and software engineering. Their origins historically are related to a number of areas, including general systems theory. While potential improvement of software development practices is linked by some leading experts to the application of more systemic methods, the current state of the practice in software engineering and information systems development shows this is some way from being achieved. The authors propose possible directions for future research and practical work on bringing together both fields with systems thinking

CLINICAL ASPECTS AND SURGICAL TREATMENT OF TUMOURS OF THE MEDIASTINUM

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Fabrication of salt–hydrogel marbles and hollow-shell microcapsules by an aerosol gelation technique

We designed a new method for preparation of liquid marbles by using hydrophilic particles. Salt–hydrogel marbles were prepared by atomising droplets of hydrogel solution in a cold air column followed by rolling of the collected hydrogel microbeads in a bed of micrometre sized salt particles. Evaporation of the water from the resulting salt marbles with a hydrogel core yielded hollow-shell salt microcapsules. The method is not limited to hydrophilic particles and could potentially be also applied to particles of other materials, such as graphite, carbon black, silica and others. The structure and morphology of the salt–hydrogel marbles were analysed by SEM and their particle size distributions were measured. We also tested the dissolution times of the dried salt marbles and compared them with those of table salt samples under the same conditions. The high accessible surface area of the shell of salt microcrystals allows a faster initial release of salt from the hollow-shell salt capsules upon their dissolution in water than from the same amount of table salt. The results suggest that such hollow-shell particles could find applications as a table salt substitute in dry food products and salt seasoning formulations with reduced salt content without the loss of saltiness