88 research outputs found
Subgroups of free idempotent generated semigroups: full linear monoid
We develop some new topological tools to study maximal subgroups of free
idempotent generated semigroups. As an application, we show that the rank 1
component of the free idempotent generated semigroup of the biordered set of a
full matrix monoid of n x n matrices, n>2$ over a division ring Q has maximal
subgroup isomorphic to the multiplicative subgroup of Q.Comment: We hope to use similar methods to study the higher rank component
On the Kurosh theorem and separability properties
AbstractWe prove a Kurosh-type subgroup theorem for free products of LERF groups. This theorem permits a better understanding of how finitely generated subgroups are embedded in finite index subgroups. Consequences include the double coset separability of free products of negatively curved surface groups. Other properties of finitely generated subgroups of such free products are studied as well
Subgroups of free idempotent generated semigroups need not be free
We use topological methods to study the maximal subgroups of the free
idempotent generated semigroup on a biordered set. We use these to give an
example of a free idempotent generated semigroup with maximal subgroup
isomorphic to the free abelian group of rank 2. This is the first example of a
non-free subgroup of a free idempotent generated semigroup
Type-specific dendritic integration in mouse retinal ganglion cells
Neural computation relies on the integration of synaptic inputs across a neuron’s dendritic arbour. However, it is far from understood how different cell types tune this process to establish cell-type specific computations. Here, using two-photon imaging of dendritic Ca2+ signals, electrical recordings of somatic voltage and biophysical modelling, we demonstrate that four morphologically distinct types of mouse retinal ganglion cells with overlapping excitatory synaptic input (transient Off alpha, transient Off mini, sustained Off, and F-mini Off) exhibit type-specific dendritic integration profiles: in contrast to the other types, dendrites of transient Off alpha cells were spatially independent, with little receptive field overlap. The temporal correlation of dendritic signals varied also extensively, with the highest and lowest correlation in transient Off mini and transient Off alpha cells, respectively. We show that differences between cell types can likely be explained by differences in backpropagation efficiency, arising from the specific combinations of dendritic morphology and ion channel densities
Corporate ethical identity as a determinant of firm performance : a test of the mediating role of stakeholder satisfaction
In this article, we empirically assess the impact of corporate ethical identity (CEI) on a firm’s financial performance. Drawing on formulations of normative and instrumental stakeholder theory, we argue that firms with a strong ethical identity achieve a greater degree of stakeholder satisfaction (SS), which, in turn, positively influences a firm’s financial performance. We analyze two dimensions of the CEI of firms: corporate revealed ethics and corporate applied ethics. Our results indicate that revealed ethics has informational worth and enhances shareholder value, whereas applied ethics has a positive impact through the improvement of SS. However, revealed ethics by itself (i.e. decoupled from ethical initiatives) is not sufficient to boost economic performance.Publicad
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