LOADS ON THE LUMBAR SPINE DURING BUNGEE JUMPING

INTRODUCTION: The purpose of this study was to quantify the load that occurs on the lumbar spine during bungee jumping and to compare these results with loads that occur during trampoline and vertical jumps. METHODS: For each of ten bungee jumpers representing two weight classes, three dimensional acceleration measurements were recorded by an accelerometer attached to their skin at the iliac spine. Similarly, two dimensional (vertical and sagittal) acceleration measurements were recorded for trampoline and vertical jumps of subjects representing different heights and landing performances. The following loading parameters were analyzed:maximum vertical acceleration, maximum sagittal acceleration, calculated vertical forces on the lumbar vertebral bodies in relation to the tensile strength for bungee jumping, calculated vertical forces on the lumbar vertebral bodies in relation to the compresive strength for trampoline and vertical jumps, relative vertical forces on the lumbar intervertebral discs. In addition, for bungee jumping, the differences between the two weight classes and the influence of body weight on vertical acceleration were examined. RESULTS: 1. During bungee jumping the vertical acceleration maxima and the relative vertical forces of vertebral bodies and intervertebral discs were significantly or high significantly greater in the lower weight class (50 - 80 kg) compared to the higher weight class (80-110 kg). 2. During bungee jumping, in both groups, the correlation between body weight and vertical acceleration maximum was negative; in the lower weight class, there was a high correlation (r = -0.995; p < 0.01) between these parameters. 3. The mean of the vertical acceleration maxima for bungee jumping (2.7 g) was lower than the corresponding means in trampoline (5.8 – 8.7 g), and the hard (3.7 – 11.1 g) and most of the soft vertical jump landings (3.3 – 7.3 g). 4. The mean of the maximal sagittal acceleration for bungee jumping (2.5 g) was higher than one group in trampoline (1.5 g), most of the soft (1 – 2.2 g) and two of the hard vertical juimp landing performances (1.1 – 1.9 g). 5. The mean of the relative vertical forces on the lumbar vertebral bodies for bungee jumping (30.3 %) was lower than in trampoline (38.3 – 59.2 %), in most of the hard vertical landing performances (34.5 – 67.3 %) and lower in the soft landing performances from 1.1 m to 1.5 m (33.2 – 44.4 %). 6. The mean of the relative vertical forces on the lumbar intervertebral discs during bungee jumping (34 %) was higher than the corresponding means in trampoline (17.1 – 27.0 %), and hard (10.0 – 29.9 %) and soft (6.5 – 19.6 %) vertical landing performances

Unsaturated Fatty Acids Affect Quorum Sensing Communication System and Inhibit Motility and Biofilm Formation of Acinetobacter baumannii

The increasing threat of Acinetobacter baumannii as a nosocomial pathogen is mainly due to the occurrence of multidrug-resistant strains that are associated with the real problem of its eradication from hospital wards. The particular ability of this pathogen to form biofilms contributes to its persistence, increases antibiotic resistance, and promotes persistent/device-related infections. We previously demonstrated that virstatin, which is a small organic compound known to decrease virulence of Vibrio cholera via an inhibition of T4-pili expression, displayed very promising activity to prevent A. baumannii biofilm development. Here, we examined the antibiofilm activity of mono-unsaturated chain fatty acids, palmitoleic (PoA), and myristoleic (MoA) acids, presenting similar action on V. cholerae virulence. We demonstrated that PoA and MoA (at 0.02 mg/mL) were able to decrease A. baumannii ATCC 17978 biofilm formation up to 38% and 24%, respectively, presented a biofilm dispersing effect and drastically reduced motility. We highlighted that these fatty acids decreased the expression of the regulator abaR from the LuxIR-type quorum sensing (QS) communication system AbaIR and consequently reduced the N-acyl-homoserine lactone production (AHL). This effect can be countered by addition of exogenous AHLs. Besides, fatty acids may have additional non-targeted effects, independent from QS. Atomic force microscopy experiments probed indeed that PoA and MoA could also act on the initial adhesion process in modifying the material interface properties. Evaluation of fatty acids effect on 22 clinical isolates showed a strain-dependent antibiofilm activity, which was not correlated to hydrophobicity or pellicle formation ability of the tested strains, and suggested a real diversity in cell-to-cell communication systems involved in A. baumannii biofilm formation.Peer reviewe

Links between seawater flooding, soil ammonia oxidiser communities and their response to changes in salinity

Acknowledgements We thank Heather Richmond and Mechthild Bömeke for providing excellent technical assistance. In addition, we thank Jessica Heublein for support with respect to basic soil analyses and Laura Lehtovirta-Morley for useful discussion on cultivation of AO. We also thank Ruth Hartwig-Kruse, Michael Kliesch and the team of the ‘Schutzstation Wattenmeer Langeness’ for support during sampling. FUNDING This work was financially supported by the Deutsche Forschungsgemeinschaft (DFG) (NA 848/1-1).Peer reviewedPostprin

Virstatin inhibits biofilm formation and motility of Acinetobacter baumannii

BACKGROUND: Acinetobacter baumannii has emerged as an opportunistic nosocomial pathogen causing infections worldwide. One reason for this emergence is due to its natural ability to survive in the hospital environment, which may be explained by its capacity to form biofilms. Cell surface appendages are important determinants of the A. baumannii biofilm formation and as such constitute interesting targets to prevent the development of biofilm-related infections. A chemical agent called virstatin was recently described to impair the virulence of Vibrio cholerae by preventing the expression of its virulence factor, the toxin coregulated pilus (type IV pilus). The objective of this work was to investigate the potential effect of virstatin on A. baumannii biofilms. RESULTS: After a dose-response experiment, we determined that 100 μM virstatin led to an important decrease (38%) of biofilms formed by A. baumannii ATCC17978 grown under static mode. We demonstrated that the production of biofilms grown under dynamic mode was also delayed and reduced. The biofilm susceptibility to virstatin was then tested for 40 clinical and reference A. baumannii strains. 70% of the strains were susceptible to virstatin (with a decrease of 10 to 65%) when biofilms grew in static mode, whereas 60% of strains respond to the treatment when their biofilms grew in dynamic mode. As expected, motility and atomic force microscopy experiments showed that virstatin acts on the A. baumannii pili biogenesis. CONCLUSIONS: By its action on pili biogenesis, virstatin demonstrated a very promising antibiofilm activity affecting more than 70% of the A. baumannii clinical isolates

Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell

The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into the competition for electron donor in a PMFC. This paper characterises the anode–rhizosphere bacterial community of a Glyceria maxima (reed mannagrass) PMFC. Electrochemically active bacteria (EAB) were located on the root surfaces, but they were more abundant colonising the graphite granular electrode. Anaerobic cellulolytic bacteria dominated the area where most of the EAB were found, indicating that the current was probably generated via the hydrolysis of cellulose. Due to the presence of oxygen and nitrate, short-chain fatty acid-utilising denitrifiers were the major competitors for the electron donor. Acetate-utilising methanogens played a minor role in the competition for electron donor, probably due to the availability of graphite granules as electron acceptors

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Analysis of shared heritability in common disorders of the brain

ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Research of innovative therapeutic tools against Acinetobacter baumannii

Acinetobacter baumanii fait aujourd’hui partie des bactéries les plus problématiques dans le monde. Responsable de nombreux pics épidémiques d’infections nosocomiales auxquelles sont associés de forts taux de mortalité, cette bactérie puise sa pathogénie dans de multiples caractéristiques qui lui permettent ainsi d’échapper au système immunitaire de l’hôte et à la plupart des traitements actuels. Capable d’adhérer à de multiples surfaces, A. baumanii persiste dans l’environnement hospitalier à travers un mode de vie communautaire au sein duquel ses capacités de survie sont exacerbées. Chez les espèces du genre Acinetobacter, le mode de vie communautaire peut prendre deux formes distinctes : le biofilm et la pellicule. Dans la première partie de cette thèse, nous avons cherché à discriminer ces deux modes de vie, chez la souche ATCC 17978, par une analyse protéomique à large échelle. Nous avons confirmé la présence de nombreux marqueurs communs aux deux communautés (transporteurs, systèmes de sécrétion, d’acquisition d’ions, adhésines et pili) et mis en exergue des systèmes spécifiquement reliés à la formation du biofilm (pilus Fim, T2SS, T1SS/pompe A1S_0535-38, LPS/LOS, motif capsulaire) et à celle de la pellicule (Gac). Grâce à l’étude de la souche A. baumannii SDF en mode biofilm, qui présente un génome plus compact, nous montrons que très peu de mécanismes moléculaires sont partagés par les deux souches étudiées. Ce résultat témoigne de la difficulté quant au développement d’un traitement dirigé contre les biofilms A. baumannii. Dans une deuxième partie, nous avons testé deux approches pour prévenir et éradiquer les biofilms à A. baumannii. La première a ciblé le Quorum Sensing (QS), système de communication essentielle à la coordination des cellules. Nous avons pu montrer que les acides gras mono-insaturés (acide palmitoléique et acide myristoléique), au même titre que la virstatine, limitait la formation de communautés à A. baumannii en inhibant l’expression du régulateur abaR nécessaire au QS. Dans une seconde stratégie, nous avons finalement évalué l’action antibactérienne et antibiofilm d’un nouveau composé d’origine naturelle : la squalamine. Dans cette étude, nous montrons pour la première fois qu’A. baumannii est capable d’entrer dans un état de dormance (persistant/VBNC) pour survivre à de fortes doses de ciprofloxacine, mais que la squalamine est capable d’éradiquer ces cellules persistantes grâce à des concentrations inférieures à la concentration hémolytique.Today, Acinetobacter baumannii is one of the most problematic pathogens in the world. This bacterium is responsible for worldwide epidemic outbreaks associated with dramatic mortality rates. It possesses high capacities to evade the immune host system and to resist to numerous available antibacterial agents. A. baumannii is also able to persist into hospital environment due to high adhesion abilities which induce community development. This process is also associated to an enhanced survival rate. In Acinetobacter genus, community modes of lif can take two forms : biofilm and pellicle. In this study on the strain ATCC 17978, we tried to discriminate these two lifestyles by a large scale proteomic analysis. We have confirmed the presence of many common community markers (transporters, ion acquisition secretion systems, adhesins and pili) and highlighted systems specifically related to biofilm (pilus Fim, T2SS, T1SS / pump A1S_0535-38, LPS / LOS, capsular pattern) and pellicle communities. Furthermore the proteomic analysis of an avirulent A. baumannii strain, SDF, in biofilm allowed to highlight peculiar metabolic pathways, specific adhesion determinants but very few markers shared by ATCC 17978. This demonstrated the difficulty in developing a treatment directed against A. baumannii biofilm. Then, we tested different approaches to prevent and eradicate biofilms. The first one targeted the Quorum Sensing system (QS), an essential communication system for cell coordination. We have showed that monounsaturated fatty acids (palmitoleic acid and myristoleic acid), like virstatin prevent the community formation of A. baumannii by inhibiting the expression of the abaR regulator required for QS. In a second strategy, we have evaluated the antibacterial and antibiofilm activity of a new natural compound : the squalamine. We showed for the first time that if ciprofloxacin treatment was able to induce a dormancy population (persistent/VBNCs) in A. baumannii, squalamine was able to eradicate this population of dormant cells