Dinâmica populacional de Acromyrmex crassispinus (Hymenoptera: Formicidae) em um plantio de Pinus taeda.

Resumo

Re-embedding agency at the workplace scale: workers and labour control in Glasgow call centres

Following recent calls for the development of a more embedded sense of labour agency, this paper focuses on the scale of the workplace which is largely absent from recent labour geography debates. Drawing on studies in the labour process tradition, the paper presents empirical research on call centre work in Glasgow, utilising this to revisit the concept of local Labour Control Regimes (LCR). We argue that rather than being simply imposed by capital and the state ‘from above’, workplace control should be seen as the product of a dialectical process of interaction and negotiation between management and labour. Labour’s indeterminacy can influence capital in case specific ways as firms adapt to labour agency and selectively tolerate and collude with certain practices and behaviours. Workers’ learned behaviour and identities are shown to affect not only recruitment patterns in unexpected ways, but also modes of accepted conduct in call centres. Accordingly, the case is made for the influence of subtle – yet pervasive – worker agency expressed at the micro-scale of the labour process itself. This, it is argued, exerts a degree of ‘bottom-up’ pressure on key fractions of capital within the local LCR

miR-182 Regulates Slit2-Mediated Axon Guidance by Modulating the Local Translation of a Specific mRNA

During brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mRNA translation. Different guidance cues elicit translation of subsets of mRNAs that differentially regulate the cytoskeleton, yet little is understood about how specific mRNAs are selected for translation. MicroRNAs (miRNAs) are critical translational regulators that act through a sequence-specific mechanism. Here, we investigate the local role of miRNAs in mRNA-specific translation during pathfinding of $\textit{Xenopus laevis }$ retinal ganglion cell (RGC) axons. Among a rich repertoire of axonal miRNAs, miR-182 is identified as the most abundant. Loss of miR-182 causes RGC axon targeting defects in vivo and impairs Slit2-induced growth cone (GC) repulsion. We find that miR-182 targets cofilin-1 mRNA, silencing its translation, and Slit2 rapidly relieves the repression without causing miR-182 degradation. Our data support a model whereby miR-182 reversibly gates the selection of transcripts for fast translation depending on the extrinsic cue.This study was supported by EMBO ( ALTF992-2011 ) and HFSP fellowships ( LT000136/2012 ) (to A.B.), University of Trento PhD studentship (to A.I.), Wellcome Trust Programme ( 085314/Z/08/Z ) (to C.E.H.), and Marie Curie Career Integration ( 618969 GUIDANCE-miR ), G. Armenise-Harvard Foundation Career, and MIUR SIR ( RBSI144NZ4 ) grants (to M.-L.B.)