9 research outputs found
The Relationship Between Isokinetic Quadriceps Strength Test and Hop Tests for Distance and One-Legged Vertical Jump Test Following Anterior Cruciate Ligament Reconstruction
Kliometrisiä lähestymistapoja sotien tutkimiseen
This chapter is a review of the many perspectives from history, political science, sociology, and economics that economic historians have applied to the study of war. Here I first review some of the scholarship on the premodern period, especially the formation of European nation states and conflicts. It is fairly clear that Europeans emerged out of this period with a comparative advantage in violence, through technological innovations and repeated warfare. Fiscal innovation and expansion was a key part of this. The period of the revolutions and Napoleonic conflicts represented a change in the nature of warfare and the arrival of total war, as well as the industrial age. The period of the world wars represents perhaps the best represented area of study for economic historians as of late. New data and scholarship has shown the mechanics of mobilization and highlighted the importance of resources in deciding these conflicts. Conversely, the Cold War period has been relatively sparsely studied, at least from the perspective of conflicts or military spending. Given the availability of new data and the opening of many archives, it is highly likely that this state of affairs will change in the near future. Economic historians have clearly made an impact in the study of long-run phenomena such as state formation, empires, and democracy. Cliometrics is well suited to the study of such topics, given the new panel and time series techniques, the rapid development of computing power, and the many new online databases.Peer reviewe
Modulation of gene expression in endothelial cells by hyperlipaemic postprandial serum from healthy volunteers
A single high-fat challenge induces plasmatic pro-inflammatory and pro-oxidative responses in the postprandial state, even in healthy men. This period is also associated with vascular endothelial dysfunction, which is an early event in the development of cardiovascular diseases. However, knowledge about the mechanisms involved in postprandial hyperlipaemia-induced endothelial dysfunction is sparse. An objective of our study was to characterize the behaviour and gene expression of vascular endothelial cells exposed to postprandial hyperlipaemic sera. Human umbilical vein endothelial cells (HUVECs) were cultured in media containing 10% serum from healthy men withdrawn either before or 4Â h after a high-fat challenge. Endothelial cell proliferation, adhesion and migration were then assessed. The transcriptomic profiles of endothelial cells exposed to pre and postprandial sera were also compared. Exposure to postprandial hyperlipaemic sera significantly decreased HUVEC proliferation when compared to preprandial serum (PÂ <Â 0.0001), while no changes in migration or endothelial/monocyte interactions were observed. The transcriptomic analysis revealed changes in the expression of 675 genes, of which 431 have a known function. Among them, a set of differentially expressed genes was linked to cell cycle regulation and apoptosis and are regulated in favour of cell cycle arrest or death. This result was confirmed by measuring the induction of apoptosis after postprandial sera exposure (PÂ =Â 0.011). Taken together, the transcriptomic results and pathway analysis showed that postprandial serum promotes apoptosis in HUVECs, potentially through the activation of the p53 network. We conclude that upon postprandial serum exposure, vascular endothelial cells transcriptionally regulate genes involved in the control of cell cycle and death to favour growth arrest and apoptosis. These findings support the hypothesis that postprandial hyperlipaemia is associated with vascular dysfunction and offer new insights into the mechanisms involved
Motor Unit Firing Behaviour of Soleus Muscle in Isometric and Dynamic Contractions
Introduction.
Understanding the detailed control of human locomotion and balance can be improved, when individual motor units can be isolated and their firing rates followed in natural movement of large, fuctionally important muscles. For this reason the present study investigated the motor unit discharge rate (MUDR) in isometric and dynamic contractions of the soleus muscle. Methods: Eleven males performed isometric (10–100% MVC) and dynamic (10–40% MVC) plantar flexions. Intramuscular EMG was measured from Soleus with bipolar wire-electrodes and decomposed with custom built “Daisy” software.
Results.
The Soleus MUDR was significantly higher in concentric compared to isometric or eccentric contractions at all submaximal force levels (P<0.05). In isometric contractions MUDR increased up to 100% MVC. Conclusion: Motor unit discharge properties of a large plantarflexor can be measured in dynamic and maximal contractions. For a given torque output, MUDR is dependent upon contraction type, as set by the major mechanical differences between concentric and eccentric actions.peerReviewe