Nimodipine has no effect on the cerebral circulation in conscious pigs, despite an increase in cardiac output

1. We studied the effects of four doses of nimodipine (0.5, 1, 2 and 4 micrograms kg-1 min-1) on systemic haemodynamics and on regional vascular beds, in particular the cerebral circulation, in conscious pigs. 2. Nimodipine caused dose-dependent, probably reflex-mediated, increases in heart rate (42% with the highest dose) and cardiac output (54%), while arterial blood pressure was only minimally affected. Left ventricular end-diastolic pressure and systemic vascular resistance decreased dose-dependently (35-40% at the highest dose) while stroke volume remained unchanged. 3. Total brain blood flow was not affected by the drug. Furthermore, we could not demonstrate any regional cerebral differences, as blood flows to both cerebral hemispheres as well as the diencephalon, cerebellum and brain stem remained unchanged.4. Blood flow to the kidneys, liver, small intestine and skin also did not change. Nimodipine caused dose-dependent increases in blood flow to the stomach (95%), myocardium (97%) and adrenal glands (102%), while blood flow to skeletal muscles (267%) increased most. 5. It is concluded that in the conscious pig, nimodipine is an arterial vasodilator which shows some selectivity for the skeletal muscle vasculature but does not increase total or regional cerebral blood flow.</p

Loneliness, cumulative inequality and social capital in later life: Two stories

The potential impact of cumulative inequality upon loneliness in later life is under-researched. This study applies Ferraro and Shippee’s axioms of cumulative inequality to the narratives of two Northern Irish older women, who completed semi-structured diary entries over a 16-week period, recording and reflecting on their social lives and their personal histories. The two women were subsequently interviewed on the basis of what they had recorded. These stories reveal how the life trajectories of these two individuals are influenced by the different experiential impact of bonding and bridging social capital. Despite similar life experiences, significant and substantial differences emerged in the women’s stories, relating to work life, social class, the restrictions of a caring role, and physical and mental health. These two narratives not only provide evidence of the impact of cumulative inequality on loneliness but also highlight the lifetime impact of socio-economic status and access to capital affecting older women’s vulnerability to loneliness

Digital technology enablers for resilient and customer driven food value chains

Food production chains have to respond to disrupted global markets and dynamic customer demands. They are coming under pressure to move from a supply to a demand-driven business model. The inherent difficulties in the lifecycle management of food products, their perishable nature, the volatility in global and regional supplier and customer markets, and the mix of objective and subjective drivers of customer demand and satisfaction, compose a challenging food production landscape. Businesses need to navigate through dynamically evolving operational risks and ensure targeted performance in terms of supply chain resilience and agility, as well as transparency and product assurance. While the industrial transition to digitalised and automated food production chains is seen as a response to such challenges, the contribution of industry 4.0 technology enablers towards this aim is not sufficiently well understood. This paper outlines the key features of high performing food production chains and performs a mapping between them and enabling technologies. As digitalisation initiatives gain priority, such mapping can help with the prioritisation of technology enablers on delivering key aspects of high performing food production chains

Poor vasoconstrictor response to adrenergic stimulation in the arteriovenous anastomoses present in the carotid vascular bed of young Yorkshire pigs

Studies using electromagnetic flowmeters and radioactive labeled microspheres (15 +/- 1 micron) have revealed that about 80% of the total common carotid artery blood flow in young domestic pigs (12-14 weeks) is shunted through arteriovenous anastomoses (AVAs). To investigate the influence of the sympathetic nervous system we measured the distribution of carotid blood flow before and after cervical sympathetic nerve stimulation (2-16 Hz), intracarotid infusions of noradrenaline (0.025-0.2 micrograms X kg-1 X min-1) or intracarotid bolus injections of noradrenaline (0.3 and 1.0 micrograms X kg-1) and clonidine (1 and 5 micrograms X kg-1). The first two interventions did not exert any effect, but bolus injections of noradrenaline and clonidine, achieving high local concentrations temporarily, caused a short-lasting decrease in AVA-flow, which was attenuated by phentolamine (1 mg X kg-1). It is concluded that the sympathetic nervous system in the carotid vascular bed of young Yorkshire pigs is poorly developed.</p