244 resultados para action cognition


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This paper offers a new insight into how organizations engage with external complexity. It applies a political action perspective that draws attention to the hitherto neglected question of how the relative power organizational leaders enjoy within their environments is significant for the actions they can take on behalf of their organizations when faced with external complexity. It identifies cognitive and relational complexity as two dimensions of the environment with which organizations have to engage. It proposes three modes whereby organizations may engage with environmental complexity that are conditioned by an organization's power within its environment. It also considers the intention associated with each mode, as well as the implications of these modes of engagement for how an organization can learn about its environment and for the use of rationality and intuition in its strategic decision-making. The closing discussion considers how this analysis integrates complexity and political action perspectives in a way that contributes to theoretical development and provides the basis for a dynamic political co-evolutionary approach. © The Author(s) 2011.

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An in vivo study in the laboratory rat model has been carried out to monitor morphological changes in adult Fasciola hepatica over a 4-day period resulting from co-treatment with triclabendazole (TCBZ) and ketoconazole (KTZ), a cytochrome P450 inhibitor. Rats were infected with the triclabendazole-resistant Oberon isolate of F. hepatica, dosed orally with triclabendazole at a dosage of 10mg/kg live weight and ketoconazole at a dosage of 10mg/kg live weight. Flukes were recovered at 24, 48, 72 and 96 h post-treatment (p.t.) and changes to fluke ultrastructure were assessed using transmission electron microscopy (TEM). Results showed an increase in the severity of changes to the fluke ultrastructure with time p.t. Swelling of the basal infolds and the associated mucopolysaccharide masses became more severe with time. Golgi complexes, if present, were greatly reduced in size and number by 96 h p.t., and sub-tegumental flooding was seen from the 72 h time-period onwards. Some sloughing of the tegumental covering over the spines was observed at 96 h p.t. The results demonstrated that the Oberon isolate is more sensitive to TCBZ action in the presence of KTZ than to TCBZ alone, reinforcing the idea that altered drug metabolism is involved in the resistance mechanism. Moreover, they support the concept that TCBZ+inhibitor combinations (aimed at altering drug pharmacokinetics and potentiating the action of TCBZ) could be used in the treatment of TCBZ-R populations of F. hepatica.

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We investigated adult age differences in dual-task costs in cognitive-sensorimotor settings without concurrent response production and with individually adjusted resource demands for the cognitive task. Twenty-four young adults (M=25.42 years, SD=3.55) and 23 older adults (M=68 years, SD=4.46) performed a cognitive task and two postural control tasks (standing on a stable and moving platform) both separately (single-task context) and concurrently (dual-task context). The cognitive task did not require response production during posture data collection and its difficulty was individually adjusted to 80% correct performance under single-task conditions. Results showed pronounced age differences in postural control in the moving platform condition, which increased further under dual-task conditions. Our findings support the assumption of increased cognitive resource demands for postural control in older adults. They extend existing work by taking two shortcomings of previous studies into account. We discuss cognitive and posture task constraints in this and previous studies as factors determining multi-tasking and its changes in later adulthood.