Supramolecular structure in the membrane of Staphylococcus aureus

The fundamental processes of life are organized and based on common basic principles. Molecular organizers, often interacting with the membrane, capitalize on cellular polarity to precisely orientate essential processes. The study of organisms lacking apparent polarity or known cellular organizers (e.g., the bacterium Staphylococcus aureus) may enable the elucidation of the primal organizational drive in biology. How does a cell choose from infinite locations in its membrane? We have discovered a structure in the S. aureus membrane that organizes processes indispensable for life and can arise spontaneously from the geometric constraints of protein complexes on membranes. Building on this finding, the most basic cellular positioning system to optimize biological processes, known molecular coordinators could introduce further levels of complexity. All life demands the temporal and spatial control of essential biological functions. In bacteria, the recent discovery of coordinating elements provides a framework to begin to explain cell growth and division. Here we present the discovery of a supramolecular structure in the membrane of the coccal bacterium Staphylococcus aureus, which leads to the formation of a large-scale pattern across the entire cell body; this has been unveiled by studying the distribution of essential proteins involved in lipid metabolism (PlsY and CdsA). The organization is found to require MreD, which determines morphology in rod-shaped cells. The distribution of protein complexes can be explained as a spontaneous pattern formation arising from the competition between the energy cost of bending that they impose on the membrane, their entropy of mixing, and the geometric constraints in the system. Our results provide evidence for the existence of a self-organized and nonpercolating molecular scaffold involving MreD as an organizer for optimal cell function and growth based on the intrinsic self-assembling properties of biological molecules

A ventricular fibrillation cardiac arrest model with extracorporeal cardiopulmonary resuscitation in rats: 8 minutes arrest time leads to increased myocardial damage but does not increase neuronal damage compared to 6 minutes

IntroductionExtracorporeal cardiopulmonary resuscitation (ECPR) is an emerging strategy in highly selected patients with refractory cardiac arrest (CA). Animal models can help to identify new therapeutic strategies to improve neurological outcome and cardiac function after global ischemia in CA. Aim of the study was to establish a reproducible ECPR rat model of ventricular fibrillation CA (VFCA) that leads to consistent neuronal damage with acceptable long-term survival rates, which can be used for future research.Materials and methodsMale Sprague Dawley rats were resuscitated with ECPR from 6 min (n = 15) and 8 min (n = 16) VFCA. Animals surviving for 14 days after return of spontaneous resuscitation (ROSC) were compared with sham operated animals (n = 10); neurological outcome was assessed daily until day 14. In the hippocampal cornu ammonis 1 region viable neurons were counted. Microglia and astrocyte reaction was assessed by Iba1 and GFAP immunohistochemistry, and collagen fibers in the myocardium were detected in Azan staining. QuPath was applied for quantification.ResultsOf the 15 rats included in the 6 min CA group, all achieved ROSC (100%) and 10 (67%) survived to 14 days; in the 8 min CA group, 15 (94%) achieved ROSC and 5 (31%) reached the endpoint. All sham animals (n = 10) survived 2 weeks. The quantity of viable neurons was significantly decreased, while the area displaying Iba1 and GFAP positive pixels was significantly increased in the hippocampus across both groups that experienced CA. Interestingly, there was no difference between the two CA groups regarding these changes. The myocardium in the 8 min CA group exhibited significantly more collagen fibers compared to the sham animals, without differences between 6- and 8-min CA groups. However, this significant increase was not observed in the 6 min CA group.ConclusionOur findings indicate a uniform occurrence of neuronal damage in the hippocampus across both CA groups. However, there was a decrease in survival following an 8-min CA. Consequently, a 6-min duration of CA resulted in predictable neurological damage without significant cardiac damage and ensured adequate survival rates up to 14 days. This appears to offer a reliable model for investigating neuroprotective therapies

Quantum Cryptography

Quantum cryptography could well be the first application of quantum mechanics at the individual quanta level. The very fast progress in both theory and experiments over the recent years are reviewed, with emphasis on open questions and technological issues.Comment: 55 pages, 32 figures; to appear in Reviews of Modern Physic

Intracellular monitoring of target protein production in Staphylococcus aureus by peptide tag-induced reporter fluorescence

An intracellular approach for monitoring protein production in Staphylococcus aureus is described. mCherry, fused to the dodecapeptide Tip, was capable of inducing tetracycline repressor (TetR). Time‐ and concentration‐dependent production of mCherry could be correlated to TetR‐controlled GFPmut2 activity. This approach can potentially be extended to native S. aureus proteins

Evaluating heart rate variability with 10 second multichannel electrocardiograms in a large population-based sample

Introduction Heart rate variability (HRV), defined as the variability of consecutive heart beats, is an important biomarker for dysregulations of the autonomic nervous system (ANS) and is associated with the development, course, and outcome of a variety of mental and physical health problems. While guidelines recommend using 5 min electrocardiograms (ECG), recent studies showed that 10 s might be sufficient for deriving vagal-mediated HRV. However, the validity and applicability of this approach for risk prediction in epidemiological studies is currently unclear to be used. Methods This study evaluates vagal-mediated HRV with ultra-short HRV (usHRV) based on 10 s multichannel ECG recordings of N = 4,245 and N = 2,392 participants of the Study of Health in Pomerania (SHIP) from two waves of the SHIP-TREND cohort, additionally divided into a healthy and health-impaired subgroup. Association of usHRV with HRV derived from long-term ECG recordings (polysomnography: 5 min before falling asleep [N = 1,041]; orthostatic testing: 5 min of rest before probing an orthostatic reaction [N = 1,676]) and their validity with respect to demographic variables and depressive symptoms were investigated. Results High correlations (r = .52–.75) were revealed between usHRV and HRV. While controlling for covariates, usHRV was the strongest predictor for HRV. Furthermore, the associations of usHRV and HRV with age, sex, obesity, and depressive symptoms were similar. Conclusion This study provides evidence that usHRV derived from 10 s ECG might function as a proxy of vagal-mediated HRV with similar characteristics. This allows the investigation of ANS dysregulation with ECGs that are routinely performed in epidemiological studies to identify protective and risk factors for various mental and physical health problems

Die Begegnung mit Fremden und das Geschichtsbewusstsein (Volume 88, Edition 1)

Freiwillige oder erzwungene Reisen von Menschen in fremde Länder und ihr Leben in der Fremde, die Begegnung mit Fremden in der eigenen Gesellschaft – das sind nicht erst Erfahrungen unserer Gegenwart oder der jüngeren Vergangenheit. Zu allen Zeiten machten viele Menschen solche Erfahrungen. Dieser Band beleuchtet das Geschichtsbewusstsein von Migranten ebenso wie die Bedeutung des Eindringens fremder Kulturen in das eigene Land und die Aufnahme dieser Erfahrungen in eigene Geschichtskonzeptionen. Der Blick wird bewusst über Europa hinaus gelenkt: Veränderte sich durch die Ankunft von Europäern auch das Geschichtsbewusstsein und die Geschichtsschreibung von Menschen in Afrika, Asien und Lateinamerika

Die Begegnung mit Fremden und das Geschichtsbewusstsein (Volume 88, Edition 1)

Freiwillige oder erzwungene Reisen von Menschen in fremde Länder und ihr Leben in der Fremde, die Begegnung mit Fremden in der eigenen Gesellschaft – das sind nicht erst Erfahrungen unserer Gegenwart oder der jüngeren Vergangenheit. Zu allen Zeiten machten viele Menschen solche Erfahrungen. Dieser Band beleuchtet das Geschichtsbewusstsein von Migranten ebenso wie die Bedeutung des Eindringens fremder Kulturen in das eigene Land und die Aufnahme dieser Erfahrungen in eigene Geschichtskonzeptionen. Der Blick wird bewusst über Europa hinaus gelenkt: Veränderte sich durch die Ankunft von Europäern auch das Geschichtsbewusstsein und die Geschichtsschreibung von Menschen in Afrika, Asien und Lateinamerika

Lack of Structural Brain Alterations associated with Insomnia: Findings from the ENIGMA-Sleep working group

Existing neuroimaging studies have reported divergent structural alterations in insomnia. Here, we performed a large-scale coordinated meta-analysis by pooling structural brain measures from 1,085 subjects with and without insomnia symptoms across three international ENIGMA-Sleep cohorts. The influence of insomnia on MRI-based brain morphometry using an insomnia brain score was assessed. We collected case-control data from two sites, as well as population-based data from another site. Within each cohort, we used an ordinary least-squares linear regression to investigate the link between the individual regional cortical thickness and subcortical volumes and the presence of insomnia symptoms. Then, we performed a fixed-effects meta-analysis across cohorts based on the first-level results. For the insomnia brain score, weighted logistic ridge regression was performed on one sample, which separated patients with insomnia disorder from controls to train a model based on the segmentation measurements. Afterward, the insomnia brain scores were validated using the other two samples. The model was used to predict the log-odds of the subjects with insomnia given individual insomnia-related brain atrophy. After adjusting for multiple comparisons, we did not detect any significant associations between insomnia symptoms and cortical or subcortical volumes, nor could we identify a global insomnia-related brain atrophy pattern. The current study found inconsistent brain morphology differences between individuals with and without insomnia across three independent cohorts. Further large-scale cross-sectional and longitudinal studies using both structural and functional neuroimaging data are warranted to decipher the pathophysiology of insomnia at the brain level