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Checkpoint controls ensure that events of the cell-division cycle are completed with fidelity and in the correct order. In budding yeast with a mutation in the motor protein dynein, the mitotic spindle is often misaligned and therefore slow to enter the neck between mother cell and budding daughter cell. When this occurs, cytokinesis (division of the cytoplasm into two) is delayed until the spindle is properly positioned. Here we describe mutations that abolish this delay, indicating the existence of a new checkpoint mechanism. One mutation lies in the gene encoding the yeast homologue of EB1, a human protein that binds the adenomatous polyposis coli (APC) protein, a tumour suppressor. EB1 is located on microtubules of the mitotic spindle and is important in spindle assembly. EB1 may therefore, by associating with microtubules, contribute to the sensor mechanism that activates the checkpoint. Another mutation affects Stt4, a phosphatidylinositol-4-OH kinase. Cold temperature is an environmental stimulus that causes misalignment of the mitotic spindle in yeast and appears to activate this checkpoint mechanism.

PurposeRecent years have witnessed the increasingly fierce competition amongst smartphone brands. Hence, smartphone firms urge to prevent current consumers from switching to maintain market position. Based on the push–pull–mooring (PPM) framework, this study aims to explore the drivers of users' intentions to switch from their current smartphone brands.Design/methodology/approachBased on previous literature and the characteristics of the smartphone purchase, this study identified one pushing, two pulling and five mooring factors. Online questionnaires were collected to test hypotheses using the structural equation modelling approach. An additional netnography study provides further support to the hypotheses.FindingsResults show that regret is a push factor that enhances consumers' switching intentions. Moreover, two pull factors, subjective norms and alternative attractiveness positively influence consumers' switching intentions. Finally, switching costs, emotional commitment and brand community engagement are mooring factors that negatively affect brand-switching intention, whereas consumers' variety seeking has a positive effect.Originality/valueThis study enriches the brand switching literature and offers significant implications for customer retention.

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Incorporation of visual-related self-action signals can help neural networks learn invariance. We describe a method that can produce a network with invariance to changes in visual input caused by eye movements and covert attention shifts. Training of the network is controlled by signals associated with eye movements and covert attention shifting. A temporal perceptual stability constraint is used to drive the output of the network toward remaining constant across temporal sequences of saccadic motions and covert attention shifts. We use a four-layer neural network model to perform the position-invariant extraction of local features and temporal integration of invariant presentations of local features in a bottom-up structure. We present results on both simulated data and real images to demonstrate that our network can acquire both position and attention shift invariance.

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Abstract. Selective attention shift can help neural networks learn invariance. We describe a method that can produce a network with invariance to changes in visual input caused by attention shifts. Training of the network is controlled by signals associated with attention shifting. A temporal perceptual stability constraint is used to drive the output of the network towards remaining constant across temporal sequences of attention shifts. We use a four-layer neural network model to perform the position-invariant extraction of local features and temporal integration of attention-shift invariant presentations of objects. We present results on both simulated data and real images, to demonstrate that our network can acquire position invariance across a sequence of attention shifts.