Voluntary Exercise Stabilizes Established Angiotensin II-Dependent Atherosclerosis in Mice through Systemic Anti-Inflammatory Effects.

We have previously demonstrated that exercise training prevents the development of Angiotensin (Ang) II-induced atherosclerosis and vulnerable plaques in Apolipoprotein E-deficient (ApoE-/-) mice. In this report, we investigated whether exercise attenuates progression and promotes stability in pre-established vulnerable lesions. To this end, ApoE-/- mice with already established Ang II-mediated advanced and vulnerable lesions (2-kidney, 1-clip [2K1C] renovascular hypertension model), were subjected to sedentary (SED) or voluntary wheel running training (EXE) regimens for 4 weeks. Mean blood pressure and plasma renin activity did not significantly differ between the two groups, while total plasma cholesterol significantly decreased in 2K1C EXE mice. Aortic plaque size was significantly reduced by 63% in 2K1C EXE compared to SED mice. Plaque stability score was significantly higher in 2K1C EXE mice than in SED ones. Aortic ICAM-1 mRNA expression was significantly down-regulated following EXE. Moreover, EXE significantly down-regulated splenic pro-inflammatory cytokines IL-18, and IL-1β mRNA expression while increasing that of anti-inflammatory cytokine IL-4. Reduction in plasma IL-18 levels was also observed in response to EXE. There was no significant difference in aortic and splenic Th1/Th2 and M1/M2 polarization markers mRNA expression between the two groups. Our results indicate that voluntary EXE is effective in slowing progression and promoting stabilization of pre-existing Ang II-dependent vulnerable lesions by ameliorating systemic inflammatory state. Our findings support a therapeutic role for voluntary EXE in patients with established atherosclerosis.

High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting.

We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s "all-out" sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; "fast" instruction) and maximal (~5 s; "hard" instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, -50, -100, and -200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (-8 ± 4% and 178 ± 11 m) but not in LA (-7 ± 3% and 181 ± 10 m) compared to NM (-5 ± 2% and 183 ± 9 m). Compared to NM (-9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (-14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (-6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (-8 ± 11%; P = 0.07) and RF (-14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0-100 (-8 ± 9%) and 0-200 ms (-10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values. Additionally, the EMG rise for VL muscle was similar (P > 0.05), whereas it increased (P < 0.05) for RF muscle during all epochs post-exercise, independently of the conditions. In summary, alteration in repeated-sprint ability and post-exercise MVC decrease were greater at high altitude than in normoxia or at low altitude. However, the post-exercise alterations in RTD were similar between normoxia and low-to-high hypoxia.

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."

Insertion dans les soins après une première hospitalisation dans un secteur pour psychose [Linkage to care after first hospitalisation for psychosis]

BACKGROUND: First hospitalisation for a psychotic episode causes intense distress to patients and families, but offers an opportunity to make a diagnosis and start treatment. However, linkage to outpatient psychiatric care remains a notoriously difficult step for young psychotic patients, who frequently interrupt treatment after hospitalisation. Persistence of symptoms, and untreated psychosis may therefore remain a problem despite hospitalisation and proper diagnosis. With persisting psychotic symptoms, numerous complications may arise: breakdown in relationships, loss of family and social support, loss of employment or study interruption, denial of disease, depression, suicide, substance abuse and violence. Understanding mechanisms that might promote linkage to outpatient psychiatric care is therefore a critical issue, especially in early intervention in psychotic disorders. OBJECTIVE: To study which factors hinder or promote linkage of young psychotic patients to outpatient psychiatric care after a first hospitalisation, in the absence of a vertically integrated program for early psychosis. Method. File audit study of all patients aged 18 to 30 who were admitted for the first time to the psychiatric University Hospital of Lausanne in the year 2000. For statistical analysis, chi2 tests were used for categorical variables and t-test for dimensional variables; p<0.05 was considered as statistically significant. RESULTS: 230 patients aged 18 to 30 were admitted to the Lausanne University psychiatric hospital for the first time during the year 2000, 52 of them with a diagnosis of psychosis (23%). Patients with psychosis were mostly male (83%) when compared with non-psychosis patients (49%). Furthermore, they had (1) 10 days longer mean duration of stay (24 vs 14 days), (2) a higher rate of compulsory admissions (53% vs 22%) and (3) were more often hospitalised by a psychiatrist rather than by a general practitioner (83% vs 53%). Other socio-demographic and clinical features at admission were similar in the two groups. Among the 52 psychotic patients, 10 did not stay in the catchment area for subsequent treatment. Among the 42 psychotic patients who remained in the catchment area after discharge, 20 (48%) did not attend the scheduled or rescheduled outpatient appointment. None of the socio demographic characteristics were associated with attendance to outpatient appointments. On the other hand, voluntary admission and suicidal ideation before admission were significantly related to attending the initial appointment. Moreover, some elements of treatment seemed to be associated with higher likelihood to attend outpatient treatment: (1) provision of information to the patient regarding diagnosis, (2) discussion about the treatment plan between in- and outpatient staff, (3) involvement of outpatient team during hospitalisation, and (4) elaboration of concrete strategies to face basic needs, organise daily activities or education and reach for help in case of need. CONCLUSION: As in other studies, half of the patients admitted for a first psychotic episode failed to link to outpatient psychiatric care. Our study suggests that treatment rather than patient's characteristics play a critical role in this phenomenon. Development of a partnership and involvement of patients in the decision process, provision of good information regarding the illness, clear definition of the treatment plan, development of concrete strategies to cope with the illness and its potential complications, and involvement of the outpatient treating team already during hospitalisation, all came out as critical strategies to facilitate adherence to outpatient care. While the current rate of disengagement after admission is highly concerning, our finding are encouraging since they constitute strategies that can easily be implemented. An open approach to psychosis, the development of partnership with patients and a better coordination between inpatient and outpatient teams should therefore be among the targets of early intervention programs. These observations might help setting up priorities when conceptualising new programs and facilitate the implementation of services that facilitate engagement of patients in treatment during the critical initial phase of psychotic disorders.

Static and dynamic shoulder stabilizer adaptations in javelin throwers: A preliminary study

BACKGROUND: Adaptations to Internal (IR) and external (ER) rotator shoulder muscles improving overhead throwing kinematics could lead to muscular strength imbalances and be considered an intrinsic risk factor for shoulder injury, as well as modified shoulder range of motion (RoM). OBJECTIVE: To establish profiles of internal and external rotation RoM and isokinetic IR and ER strength in adolescent- and national-level javelin throwers. METHODS: Fourteen healthy subjects were included in this preliminary cross-sectional study, 7 javelin throwers (JTG) and 7 nonathletes (CG). Passive internal and external rotation RoM were measured at 90 degrees of shoulder abduction. Isokinetic strength of dominant and non-dominant IR and ER was evaluated during concentric (60, 120 and 240 degrees/s) and eccentric (60 degrees/s) contractions by Con-Trex (R) dynamometer with the subject in a seated position with 45 degrees of shoulder abduction in the scapular plane. RESULTS: We reported significantly lower internal rotation and significantly higher external rotation RoM in JTG than in CG. Concentric and eccentric IR and ER strength were significantly higher for the dominant shoulder side in JTG (P < 0.05), without significant differences in ER/IR ratios. CONCLUSIONS: The main finding of this preliminary study confirmed static and dynamic shoulder stabilizer adaptations due to javelin throw practice in a population of adolescent- and national-level javelin throwers.

Les débuts de la communication à trois. Interactions visuelles triadiques entre père, mère et bébé

Plusieurs auteurs ont montré que les échanges visuels entre des mères dépressives ou psychotiques et leur bébé présentent de multiples perturbations : dans cet article, les auteurs proposent une étude exploratoire portant sur les échanges visuels père-mère- bébé (9-18 semaines) dans deux groupes de familles, un groupe suivi pour des difficultés du post-partum et un groupe témoin. Les observations sont réalisées dans le cadre d'un jeu à trois structuré selon diverses modalités d'interaction (un parent joue avec l'enfant en présence de l'autre parent / les deux parents jouent conjointement avec le bébé). Les variables retenues concernent d'une part le niveau d'attention visuelle conjointe des partenaires, d'autre part l'évolution de cette attention visuelle au cours du jeu. Les résultats révèlent que les échanges visuels sont plus intenses dans les familles fonctionnelles, ce qui semble indiquer que l'engagement visuel triadique établi par les partenaires peut être représentatif du fonctionnement de la triade à un moment donné de son développement. D'autre part, l'analyse de l'évolution de l'engagement visuel au travers des différents contextes de jeu amène les auteurs à proposer l'hypothèse d'une « alliance triadique » établie conjointement par les trois partenaires et formant la matrice de leurs échanges dyadiques et triadiques. De façon plus générale, les auteurs supposent que l'établissement de cette alliance joue un rôle déterminant pour le développement et l'autonomisa- tion du bébé au sein de sa famille. Disorders in the visual interaction between depressive or psychotic mothers and their baby have been widely described : in this paper, the authors propose an exploratory study of father-mother-infant visual interaction (infants are 9-18 weeks old) in two groups of families, voluntary families and families in therapy for post-par turn disorders. The observations are gathered during a three-partner play, involving different kinds of triadic interaction (one parent plays with the infant, the other parent being « only present » / both parents play together with the child). The analyses have focused on the amount of visual attention shared by the partners and on the evolution of visual interaction during the game. Results show that triadic interaction is more intense in functional triads, which means that shared visual attention may be representative of the more general functioning of the family at a definite stage of its development. Furthermore, considering the sequential organization of visual interaction throughout the game led the authors to the construct of a « triadic alliance », jointly established by the three partners and providing a matrix for their dyadic and triadic interaction. On a more general level, such an alliance could play an important role for the development and the autonomy of the baby within his j her family.

21st century climate change threatens mountain flora unequally across Europe

Continental-scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill-suited for assessment of species-specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high-resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36-55% of alpine species, 31-51% of subalpine species and 19-46% of montane species lose more than 80% of their suitable habitat by 2070-2100. While our high-resolution analyses consistently indicate marked levels of threat to cold-adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation.

Evolution of anaesthesia care and related events between 1996 and 2010 in a developed country

Background: Anaesthesia Databank Switzerland (ADS) is a voluntary data registry introduced in 1996. The goal was to promote quality in anaesthesiology. Methods: Analysis of routinely recorded adverse events. Internal and external benchmark comparisons between anaesthesia departments. Results: In 2010, the database included 2'158'735 anaesthetic procedures. Forty-four anaesthesia departments were participating to the data collection in 2010. Over time, the number of patients in older age groups increased, the largest group being patients aged 50 to 64 years. Over time, the percentage of patients with ASA physical status score 1 decreased while the number of ASA 2 or 3 patients increased. The most frequent co-morbidities were hypertension (21%), smoking (16%), allergy (15%), and obesity (12%). Between 1996 and 2010, 146'459 adverse events were recorded, of which 34% were cardiovascular, 7% respiratory, 39% specific to anaesthesia and 17% nonspecific. The overall proportion of adverse events decreased over time, whatever their severity. Conclusion: The ADS routine data collection contributes to monitoring the trends of anaesthesia care in Switzerland.

Alterations of Neuromuscular Function after the World's Most Challenging Mountain Ultra-Marathon.

We investigated the physiological consequences of the most challenging mountain ultra-marathon (MUM) in the world: a 330-km trail run with 24000 m of positive and negative elevation change. Neuromuscular fatigue (NMF) was assessed before (Pre-), during (Mid-) and after (Post-) the MUM in experienced ultra-marathon runners (n = 15; finish time  = 122.43 hours ±17.21 hours) and in Pre- and Post- in a control group with a similar level of sleep deprivation (n = 8). Blood markers of muscle inflammation and damage were analyzed at Pre- and Post-. Mean ± SD maximal voluntary contraction force declined significantly at Mid- (-13±17% and -10±16%, P<0.05 for knee extensor, KE, and plantar flexor muscles, PF, respectively), and further decreased at Post- (-24±13% and -26±19%, P<0.01) with alteration of the central activation ratio (-24±24% and -28±34% between Pre- and Post-, P<0.05) in runners whereas these parameters did not change in the control group. Peripheral NMF markers such as 100 Hz doublet (KE: -18±18% and PF: -20±15%, P<0.01) and peak twitch (KE: -33±12%, P<0.001 and PF: -19±14%, P<0.01) were also altered in runners but not in controls. Post-MUM blood concentrations of creatine kinase (3719±3045 Ul·(1)), lactate dehydrogenase (1145±511 UI·L(-1)), C-Reactive Protein (13.1±7.5 mg·L(-1)) and myoglobin (449.3±338.2 µg·L(-1)) were higher (P<0.001) than at Pre- in runners but not in controls. Our findings revealed less neuromuscular fatigue, muscle damage and inflammation than in shorter MUMs. In conclusion, paradoxically, such extreme exercise seems to induce a relative muscle preservation process due likely to a protective anticipatory pacing strategy during the first half of MUM and sleep deprivation in the second half.

Genome-wide association and genetic functional studies identify autism susceptibility candidate 2 gene (AUTS2) in the regulation of alcohol consumption.

Alcohol consumption is a moderately heritable trait, but the genetic basis in humans is largely unknown, despite its clinical and societal importance. We report a genome-wide association study meta-analysis of ∼2.5 million directly genotyped or imputed SNPs with alcohol consumption (gram per day per kilogram body weight) among 12 population-based samples of European ancestry, comprising 26,316 individuals, with replication genotyping in an additional 21,185 individuals. SNP rs6943555 in autism susceptibility candidate 2 gene (AUTS2) was associated with alcohol consumption at genome-wide significance (P = 4 × 10(-8) to P = 4 × 10(-9)). We found a genotype-specific expression of AUTS2 in 96 human prefrontal cortex samples (P = 0.026) and significant (P < 0.017) differences in expression of AUTS2 in whole-brain extracts of mice selected for differences in voluntary alcohol consumption. Down-regulation of an AUTS2 homolog caused reduced alcohol sensitivity in Drosophila (P < 0.001). Our finding of a regulator of alcohol consumption adds knowledge to our understanding of genetic mechanisms influencing alcohol drinking behavior.

Naltrexone-assisted rapid methadone discontinuation : a pilot study

Rapport de Synthèse : Un sevrage lent comme méthode élective pour l'interruption de la méthadone est coûteux en termes de temps, le plus souvent associé à un taux élevé d'abandon. Bien que les méthodes ultrarapides de désintoxication des opiacés aient gagné en popularité récemment, elles sont chères et posent les problèmes spécifiques liés aux patients traités par la méthadone. Méthodologie: ont été inclus dans l'étude dix patients en traitement de substitution avec de la méthadone. La dernière dose de méthadone a été administrée le matin même du jour de l'admission, en préalable à l'hospitalisation. Les médicaments suivants ont été administrés le jour suivant l'admission: ondansetron 36mg, ranitidine 40mg, loperamide 8m., clonazepam 4m., promazine 1OOmg, metoclopramide 70mg, naltrexone 5Omg. L'échelle objective de sevrage des opiacés (Objective Opiate Withdrawal Scale) a été appliquée au deuxième, troisième et quatrième jour d'hospitalisation, deux fois par jour, à 8h00 et 18h00. Un suivi a été réalisé sous la forme d'entretiens téléphoniques pendant une semaine, respectivement six mois après la date de sortie de l'hôpital, faisant suite à la désintoxication. Un autre entretient téléphonique a été réalisé dans les six mois suivant le "post-sevrage", avec pour objectif d'investiguer la continuité du traitément, une éventuelle rechute dans l'abus de drogues et une possible réintroduction de la méthadone. Résultats: nous avons pu déterminer quatre groupes de symptômes, sur la base d'une observation de trois jours d'évolution: 1) Les signes typiques du syndrome de sevrage de retrait des opiacés, symptôme de froid et chaud, pilo-érection, anxiété caractérisée par une intensité initiale élevée et une disparition relativement continue. 2) Hyperactivité neurovégétative caractérisée par une intensité initiale élevée et une rapide disparition. 3) Phénomènes neurovégétatifs dont l'intensité s'est maintenue durant toute la période d'observation. 4) Contractions musculaires, insomnies et anorexie, manque d'appétit, réapparaissant chez certains patients au 2ème et au début du 3ème jour. Conclusions: une procédure courte de désintoxication utilisant une dose unique de naltrexone s'avère être une méthode alternative valable pour un sevrage de la méthadone. Cette méthode semble accélérer et écourter la symptomatologie associée au sevrage. Le cours des symptômes peut être interprété comme biphasique. Une première phase de retrait est éminemment caractérisée par tous les symptômes typiques eux-mêmes et probablement induits par la naltrexone. La seconde phase, pour un plus petit nombre de patients, peut être interprétée comme en corrélation avec une concentration de méthadone en diminution significative ultérieurement.

Hypoxic contraction of small pulmonary arteries from normal and endotoxemic rats: fundamental role of NO.

The present study was aimed at examining the role of nitric oxide (NO) in the hypoxic contraction of isolated small pulmonary arteries (SPA) in the rat. Animals were treated with either saline (sham experiments) or Escherichia coli lipolysaccharide [LPS, to obtain expression of the inducible NO synthase (iNOS) in the lung] and killed 4 h later. SPA (300- to 600-micrometer outer diameter) were mounted as rings in organ chambers for the recording of isometric tension, precontracted with PGF2alpha, and exposed to either severe (bath PO2 8 +/- 3 mmHg) or milder (21 +/- 3 mmHg) hypoxia. In SPA from sham-treated rats, contractions elicited by severe hypoxia were completely suppressed by either endothelium removal or preincubation with an NOS inhibitor [NG-nitro-L-arginine methyl ester (L-NAME), 10(-3) M]. In SPA from LPS-treated rats, contractions elicited by severe hypoxia occurred irrespective of the presence or absence of endothelium and were largely suppressed by L-NAME. The milder hypoxia elicited no increase in vascular tone. These results indicate an essential role of NO in the hypoxic contractions of precontracted rat SPA. The endothelium independence of HPV in arteries from LPS-treated animals appears related to the extraendothelial expression of iNOS. The severe degree of hypoxia required to elicit any contraction is consistent with a mechanism of reduced NO production caused by a limited availability of O2 as a substrate for NOS.

Experimental peripheral arterial disease: new insights into muscle glucose uptake, macrophage, and T-cell polarization during early and late stages.

Peripheral arterial disease (PAD) is a common disease with increasing prevalence, presenting with impaired walking ability affecting patient's quality of life. PAD epidemiology is known, however, mechanisms underlying functional muscle impairment remain unclear. Using a mouse PAD model, aim of this study was to assess muscle adaptive responses during early (1 week) and late (5 weeks) disease stages. Unilateral hindlimb ischemia was induced in ApoE(-/-) mice by iliac artery ligation. Ischemic limb perfusion and oxygenation (Laser Doppler imaging, transcutaneous oxygen pressure assessments) significantly decreased during early and late stage compared to pre-ischemia, however, values were significantly higher during late versus early phase. Number of arterioles and arteriogenesis-linked gene expression increased at later stage. Walking ability, evaluated by forced and voluntary walking tests, remained significantly decreased both at early and late phase without any significant improvement. Muscle glucose uptake ([18F]fluorodeoxyglucose positron emission tomography) significantly increased during early ischemia decreasing at later stage. Gene expression analysis showed significant shift in muscle M1/M2 macrophages and Th1/Th2 T cells balance toward pro-inflammatory phenotype during early ischemia; later, inflammatory state returned to neutrality. Muscular M1/M2 shift inhibition by a statin prevented impaired walking ability in early ischemia. High-energy phosphate metabolism remained unchanged (31-Phosphorus magnetic resonance spectroscopy). Results show that rapid transient muscular inflammation contributes to impaired walking capacity while increased glucose uptake may be a compensatory mechanisms preserving immediate limb viability during early ischemia in a mouse PAD model. With time, increased ischemic limb perfusion and oxygenation assure muscle viability although not sufficiently to improve walking impairment. Subsequent decreased muscle glucose uptake may partly contribute to chronic walking impairment. Early inflammation inhibition and/or late muscle glucose impairment prevention are promising strategies for PAD management.

Influence of inter-electrode distance, contraction type, and muscle on the relationship between the sEMG power spectrum and contraction force.

INTRODUCTION: Spectral frequencies of the surface electromyogram (sEMG) increase with contraction force, but debate still exists on whether this increase is affected by various methodological and anatomical factors. This study aimed to investigate the influence of inter-electrode distance (IED) and contraction modality (step-wise vs. ramp) on the changes in spectral frequencies with increasing contraction strength for the vastus lateralis (VL) and vastus medialis (VM) muscles. METHODS: Twenty healthy male volunteers were assessed for isometric sEMG activity of the VM and VL, with the knee at 90° flexion. Subjects performed isometric ramp contractions in knee extension (6-s duration) with the force gradually increasing from 0 to 80 % MVC. Also, subjects performed 4-s step-wise isometric contractions at 10, 20, 30, 40, 50, 60, 70, and 80 % MVC. Interference sEMG signals were recorded simultaneously at different IEDs: 10, 20, 30, and 50 mm. The mean (F mean) and median (F median) frequencies and root mean square (RMS) of sEMG signals were calculated. RESULTS: For all IEDs, contraction modalities, and muscles tested, spectral frequencies increased significantly with increasing level of force up to 50-60 % MVC force. Spectral indexes increased systematically as IED was decreased. The sensitivity of spectral frequencies to changes in contraction force was independent of IED. The behaviour of spectral indexes with increasing contraction force was similar for step-wise and ramp contractions. CONCLUSIONS: In the VL and VM muscles, it is highly unlikely that a particular inter-electrode distance or contraction modality could have prevented the observation of the full extent of the increase in spectral frequencies with increasing force level.

NanoImpactNet - Stakeholders' knowledge needs for research on the health and environmental impact of nanomaterials

NanoImpactNet (NIN) is a multidisciplinary European Commission funded network on the environmental, health and safety (EHS) impact of nanomaterials. The 24 founding scientific institutes are leading European research groups active in the fields of nanosafety, nanorisk assessment and nanotoxicology. This 4−year project is the new focal point for information exchange within the research community. Contact with other stakeholders is vital and their needs are being surveyed. NIN is communicating with 100s of stakeholders: businesses; internet platforms; industry associations; regulators; policy makers; national ministries; international agencies; standard−setting bodies and NGOs concerned by labour rights, EHS or animal welfare. To improve this communication, internet research, a questionnaire distributed via partners and targeted phone calls were used to identify stakeholders' interests and needs. Knowledge gaps and the necessity for further data mentioned by representatives of all stakeholder groups in the targeted phone calls concerned: potential toxic and safety hazards of nanomaterials throughout their lifecycles; fate and persistence of nanoparticles in humans, animals and the environment; risks associated to nanoparticle exposure; participation in the preparation of nomenclature, standards, methodologies, protocols and benchmarks; development of best practice guidelines; voluntary schemes on responsibility; databases of materials, research topics and themes. Findings show that stakeholders and NIN researchers share very similar knowledge needs, and that open communication and free movement of knowledge will benefit both researchers and industry. Consequently NIN will encourage stakeholders to be active members. These survey findings will be used to improve NIN's communication tools to further build on interdisciplinary relationships towards a healthy future with nanotechnology.