The "Abdominal Circulatory Pump": An Auxiliary Heart during Exercise?

Apart from its role as a flow generator for ventilation the diaphragm has a circulatory role. The cyclical abdominal pressure variations from its contractions cause swings in venous return from the splanchnic venous circulation. During exercise the action of the abdominal muscles may enhance this circulatory function of the diaphragm. Eleven healthy subjects (25 ± 7 year, 70 ± 11 kg, 1.78 ± 0.1 m, 3 F) performed plantar flexion exercise at ~4 METs. Changes in body volume (ΔVb) and trunk volume (ΔVtr) were measured simultaneously by double body plethysmography. Volume of blood shifts between trunk and extremities (Vbs) was determined non-invasively as ΔVtr-ΔVb. Three types of breathing were studied: spontaneous (SE), rib cage (RCE, voluntary emphasized inspiratory rib cage breathing), and abdominal (ABE, voluntary active abdominal expiration breathing). During SE and RCE blood was displaced from the extremities into the trunk (on average 0.16 ± 0.33 L and 0.48 ± 0.55 L, p < 0.05 SE vs. RCE), while during ABE it was displaced from the trunk to the extremities (0.22 ± 0.20 L p < 0.001, p < 0.05 RCE and SE vs. ABE respectively). At baseline, Vbs swings (maximum to minimum amplitude) were bimodal and averaged 0.13 ± 0.08 L. During exercise, Vbs swings consistently increased (0.42 ± 0.34 L, 0.40 ± 0.26 L, 0.46 ± 0.21 L, for SE, RCE and ABE respectively, all p < 0.01 vs. baseline). It follows that during leg exercise significant bi-directional blood shifting occurs between the trunk and the extremities. The dynamics and partitioning of these blood shifts strongly depend on the relative predominance of the action of the diaphragm, the rib cage and the abdominal muscles. Depending on the partitioning between respiratory muscles for the act of breathing, the distribution of blood between trunk and extremities can vary by up to 1 L. We conclude that during exercise the abdominal muscles and the diaphragm might play a role of an "auxiliary heart."

The international standardisation arena and the civil society participation stakes : results of the INTERTERM project

International standards are playing an increasingly important role in market governance while frequently exerting direct effects on health, safety and the environment. Yet civil society, more often than not, is absent from the standardisation procedures. The recommendation made here is to foster the participation of civil society actors in standardisation by framing standardisation topics in a way that will encourage the mobilisation of these actors in accordance with their repertoire of actions and interests and by organising the plural expertise required for the effective participation that is necessary if they are to exert an influence.

Les arènes de la normalisation internationale à l'épreuve de la participation de la société civile : résultats du projet INTERNORM

Les normes internationales occupent une place de plus en plus importante dans la gouvernance des marchés et ont souvent une incidence directe sur la santé, la sécurité et l'environnement. Mais la société civile est le plus souvent absente des procédures de normalisation. Il est recommandé de favoriser la participation des acteurs de la société civile dans la normalisation par une mise en forme des travaux de normalisation à même d'encourager leur mobilisation selon les thèmes et enjeux abordés et par l'organisation de l'expertise plurielle requise pour une participation effective à même de leur conférer une certaine influence.

An Explanatory Approach to the Political Uses of ICT Initiatives for Participation : Institutions, Context, and Characteristics of the Actors

Political actors use ICTs in a different manner and in different degrees when it comes to achieving a closer relationship between the public and politicians. Usually, political parties develop ICT strategies only for electoral campaigning and therefore restrain ICT usages to providing information and establishing a few channels of communication. By contrast, local governments make much more use of ICT tools for participatory and deliberative purposes. These differences in usages have not been well explained in the literature because of a lack of a comprehensive explanatory model. This chapter seeks to build the basis for this model, that is, to establish which factors affect and condition different political uses of ICTs and which principles underlie that behaviour. We consider that political actors are intentional and their behaviour is mediated by the political institutions and the socioeconomic context of the country. Also, though, the actor¿s own characteristics, such as the type and size of the organization or the model of e-democracy that the actor upholds, can have an influence in launching ICT initiatives for approaching the public.

Online and Offline Participation at the Local Level : A Quantitative Analysis of the Catalan Municipalities

This paper presents a first analysis on local electronic participatory experiences in Catalonia. The analysis is based on a database constructed and collected by the authors. The paper carries out an explanatory analysis of local initiatives in eparticipationand off line participation taking into account political variables (usually not considered in this kind of analysis) but also classical socio-economic variables that characterise municipalities. Hence, we add a quantitative analysis to the numerous case studies on local e-participation experiences. We have chosen Catalonia because is one of the European regions with more initiatives and one that has enjoyed considerable local governmental support to citizen participation initiatives since the 80s. The paper offers a characterisation of these experiences and a first explanatory analysis, considering: i) the institutional context in which these experiences are embedded, ii) the characteristics of the citizen participation processes and mechanisms on-line, and iii) a set of explanatory variables composed by the population size, thepolitical adscription of the mayor, the electoral abstention rate, age, income and level ofeducation in the municipality. The model that we present is explanatory for the municipalities with more than 20,000 inhabitants but it is not for the fewer than 20,000inhabitants. Actually, the number of participatory activities developed by these last municipalities is very low. Among all the variables, population size becomes the mostinfluential variable. Political variables such as political party of the mayor and the localabstention rate have a certain influence but that have to be controlled by population size.

Surfing the Net: A Pathway to Participation for the Politically Uninterested?

This article explores whether use of the Internetchanges the role that political motivation hastraditionally played in classic explanations ofparticipation. We ask if, by reducing so dramatically the costs of political participation,the Internet causes interest in politics to loseimportance as a causal factor of participation.We examine this issue analysing a representativesurvey of the Spanish population which deals withpolitical participation and Internet use. Theresults show that use of Internet has a directeffect on participation independently of motivation, and that, in order to participate online, skilled Internet users do not need to be motivated or interested in politics.

Online and Offline Participation at the Local level: A Quantitative Analysis of the Catalan Municipalities

This article presents an analysis on local participatory experiences in Catalonia,both online and in-person. The analysis is based on a database set up by theauthors. The article carries out an explanatory analysis of local participatoryinitiatives (on- and offline) taking into account political variables (not usually con-sidered in this kind of analysis) and also classical socio-economic variables thatcharacterize municipalities. Hence, we add a quantitative analysis to the numerouscase studies on local e-participation experiences. We have chosen Catalonia becauseit is one of the European regions with more initiatives and a considerable localgovernment support for citizen participation initiatives since the 1980s. Thearticle offers a characterization of these experiences and an explanatory analysis,considering: (i) the institutional context in which these experiences are embedded,(ii) the citizen participation processes and mechanisms online and (iii) a set ofexplanatory variables composed of the population size and the province to whichthe municipality belongs, the political tendency of the mayor, the electoral absten-tion rate, age, income, level of education, broadband connection and users of theInternet in the municipality. The model that we present is explanatory for munici-palities with more than 20,000 inhabitants but it is not for fewer than 20,000inhabitants. Actually, the majority of these latter municipalities have not developedany participatory activities. Among all the variables, population size is the mostinfluential variable and affects the influence of other variables, such as the politicalparty of the mayor, the local abstention rate and the province.

Circulating progenitor cells during exercise, muscle electro-stimulation and intermittent hypobaric hypoxia in patients with traumatic brain injury. A pilot study

BACKGROUND: Circulating progenitor cells (CPC) treatments may have great potential for the recovery of neurons and brain function. OBJECTIVE: To increase and maintain CPC with a program of exercise, muscle electro-stimulation (ME) and/or intermittent-hypobaric-hypoxia (IHH), and also to study the possible improvement in physical or psychological functioning of participants with Traumatic Brain Injury (TBI). METHODS: Twenty-one participants. Four groups: exercise and ME group (EEG), cycling group (CyG), IHH and ME group (HEG) and control group (CG). Psychological and physical stress tests were carried out. CPC were measured in blood several times during the protocol. RESULTS: Psychological tests did not change. In the physical stress tests the VO2 uptake increased in the EEG and the CyG, and the maximal tolerated workload increased in the HEG. CPC levels increased in the last three weeks in EEG, but not in CyG, CG and HEG. CONCLUSIONS: CPC levels increased in the last three weeks of the EEG program, but not in the other groups and we did not detect performed psychological test changes in any group. The detected aerobic capacity or workload improvement must be beneficial for the patients who have suffered TBI, but exercise type and the mechanisms involved are not clear.

Epigenetic alterations in hippocampus of SAMP8 senescent mice and modulation by voluntary physical exercise.

The senescence-accelerated SAMP8 mouse model displays features of cognitive decline and Alzheimer's disease. With the purpose of identifying potential epigenetic markers involved in aging and neurodegeneration, here we analyzed the expression of 84 mature miRNAs, the expression of histone-acetylation regulatory genes and the global histone acetylation in the hippocampus of 8-month-old SAMP8 mice, using SAMR1 mice as control. We also examined the modulation of these parameters by 8 weeks of voluntary exercise. Twenty-one miRNAs were differentially expressed between sedentary SAMP8 and SAMR1 mice and seven miRNAs were responsive to exercise in both strains. SAMP8 mice showed alterations in genes involved in protein acetylation homeostasis such as Sirt1 and Hdac6 and modulation of Hdac3 and Hdac5 gene expression by exercise. Global histone H3 acetylation levels were reduced in SAMP8 compared with SAMR1 mice and reached control levels in response to exercise. In sum, data presented here provide new candidate epigenetic markers for aging and neurodegeneration and suggest that exercise training may prevent or delay some epigenetic alterations associated with accelerated aging.

Macroautophagic process was differentially modulated by long-term moderate exercise in rat brain and peripheral tissues

The autophagic process is a lysosomal degradation pathway, which is activated during stress conditions, such as starvation or exercise. Regular exercise has beneficial effects on human health, including neuroprotection. However, the cellular mechanisms underlying these effects are incompletely understood. Endurance and a single bout of exercise induce autophagy not only in brain but also in peripheral tissues. However, little is known whether autophagy could be modulated in brain and peripheral tissues by long-term moderate exercise. Here, we examined the effects on macroautophagy process of long-term moderate treadmill training (36 weeks) in adult rats both in brain (hippocampus and cerebral cortex) and peripheral tissues (skeletal muscle, liver and heart). We assessed mTOR activation and the autophagic proteins Beclin 1, p62, LC3B (LC3B-II/LC3B-I ratio) and the lysosomal protein LAMP1, as well as the ubiquitinated proteins. Our results showed in the cortex of exercised rats an inactivation of mTOR, greater autophagy flux (increased LC3-II/LC3-I ratio and reduced p62) besides increased LAMP1. Related with these effects a reduction in the ubiquitinated proteins was observed. No significant changes in the autophagic pathway were found either in hippocampus or in skeletal and cardiac muscle by exercise. Only in the liver of exercised rats mTOR phosphorylation and p62 levels increased, which could be related with beneficial metabolic effects in this organ induced by exercise. Thus, our findings suggest that long-term moderate exercise induces autophagy specifically in the cortex

Epigenetic alterations in hippocampus of SAMP8 senescent mice and modulation by voluntary physical exercise.

The senescence-accelerated SAMP8 mouse model displays features of cognitive decline and Alzheimer's disease. With the purpose of identifying potential epigenetic markers involved in aging and neurodegeneration, here we analyzed the expression of 84 mature miRNAs, the expression of histone-acetylation regulatory genes and the global histone acetylation in the hippocampus of 8-month-old SAMP8 mice, using SAMR1 mice as control. We also examined the modulation of these parameters by 8 weeks of voluntary exercise. Twenty-one miRNAs were differentially expressed between sedentary SAMP8 and SAMR1 mice and seven miRNAs were responsive to exercise in both strains. SAMP8 mice showed alterations in genes involved in protein acetylation homeostasis such as Sirt1 and Hdac6 and modulation of Hdac3 and Hdac5 gene expression by exercise. Global histone H3 acetylation levels were reduced in SAMP8 compared with SAMR1 mice and reached control levels in response to exercise. In sum, data presented here provide new candidate epigenetic markers for aging and neurodegeneration and suggest that exercise training may prevent or delay some epigenetic alterations associated with accelerated aging.

Macroautophagic process was differentially modulated by long-term moderate exercise in rat brain and peripheral tissues

The autophagic process is a lysosomal degradation pathway, which is activated during stress conditions, such as starvation or exercise. Regular exercise has beneficial effects on human health, including neuroprotection. However, the cellular mechanisms underlying these effects are incompletely understood. Endurance and a single bout of exercise induce autophagy not only in brain but also in peripheral tissues. However, little is known whether autophagy could be modulated in brain and peripheral tissues by long-term moderate exercise. Here, we examined the effects on macroautophagy process of long-term moderate treadmill training (36 weeks) in adult rats both in brain (hippocampus and cerebral cortex) and peripheral tissues (skeletal muscle, liver and heart). We assessed mTOR activation and the autophagic proteins Beclin 1, p62, LC3B (LC3B-II/LC3B-I ratio) and the lysosomal protein LAMP1, as well as the ubiquitinated proteins. Our results showed in the cortex of exercised rats an inactivation of mTOR, greater autophagy flux (increased LC3-II/LC3-I ratio and reduced p62) besides increased LAMP1. Related with these effects a reduction in the ubiquitinated proteins was observed. No significant changes in the autophagic pathway were found either in hippocampus or in skeletal and cardiac muscle by exercise. Only in the liver of exercised rats mTOR phosphorylation and p62 levels increased, which could be related with beneficial metabolic effects in this organ induced by exercise. Thus, our findings suggest that long-term moderate exercise induces autophagy specifically in the cortex