638 research outputs found
Synchronization of organ pipes: experimental observations and modeling
We report measurements on the synchronization properties of organ pipes.
First, we investigate influence of an external acoustical signal from a
loudspeaker on the sound of an organ pipe. Second, the mutual influence of two
pipes with different pitch is analyzed. In analogy to the externally driven, or
mutually coupled self-sustained oscillators, one observes a frequency locking,
which can be explained by synchronization theory. Further, we measure the
dependence of the frequency of the signals emitted by two mutually detuned
pipes with varying distance between the pipes. The spectrum shows a broad
``hump'' structure, not found for coupled oscillators. This indicates a complex
coupling of the two organ pipes leading to nonlinear beat phenomena.Comment: 24 pages, 10 Figures, fully revised, 4 big figures separate in jpeg
format. accepted for Journal of the Acoustical Society of Americ
Unmet needs in patients with first-episode schizophrenia: a longitudinal perspective
Background This study aimed to identify the course of unmet needs by patients with a first episode of schizophrenia and to determine associated variables. Method We investigated baseline assessments in the European First Episode Schizophrenia Trial (EUFEST) and also follow-up interviews at 6 and 12 months. Latent class growth analysis was used to identify patient groups based on individual differences in the development of unmet needs. Multinomial logistic regression determined the predictors of group membership. Results Four classes were identified. Three differed in their baseline levels of unmet needs whereas the fourth had a marked decrease in such needs. Main predictors of class membership were prognosis and depression at baseline, and the quality of life and psychosocial intervention at follow-up. Depression at follow-up did not vary among classes. Conclusions We identified subtypes of patients with different courses of unmet needs. Prognosis of clinical improvement was a better predictor for the decline in unmet needs than was psychopathology. Needs concerning social relationships were particularly persistent in patients who remained high in their unmet needs and who lacked additional psychosocial treatmen
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Best practices to maximize the use and reuse of quantitative and systems pharmacology models: recommendations from the United Kingdom quantitative and systems pharmacology network
The lack of standardization in the way that quantitative and systems pharmacology (QSP) models are developed, tested, and documented hinders their reproducibility, reusability, and expansion or reduction to alternative contexts. This in turn undermines the potential impact of QSP in academic, industrial, and regulatory frameworks. This article presents a minimum set of recommendations from the UK Quantitative and Systems Pharmacology Network (UK QSP Network) to guide QSP practitioners seeking to maximize their impact, and stakeholders considering the use of QSP models in their environment
From Teamchef Arminius to Hermann Junior: glocalised discourse about a national foundation myth
If for much of the nineteenth and twentieth centuries, the ‘Battle of the Teutoburg Forest’, fought in 9 CE between Roman armies and Germanic tribes, was predominantly a reference point for nationalist and chauvinist discourses in Germany, the first decade of the twenty-first century has seen attempts to link public remembrance with local/regional identities on the one hand and international/intercultural contact on the other. In the run up to and during the ‘anniversary year’ of 2009, German media, sports institutions and various other official institutions articulating tourist, economic and political interests attempted to create a new ‘glocalised’ version of the public memory of the Teutoburg battle. Combining methods of Cognitive Linguistics and Critical Discourse Analysis, the paper analyses the narrative and argumentative topoi employed in this re-orientation of public memory, with a special emphasis on hybrid, post-national identity-construction. Das zweitausendjährige Gedenkjahr der „Schlacht im Teutoburger Wald“ im Jahr 2009 bot eine günstige Gelegenheit, die bis in die zweite Hälfte des 20. Jahrhunderts dominante Tradition nationalistisch–chauvinistischer Deutungen des Sieges von germanischen Stämmen über drei römische Legionen zu korrigieren und zu überwinden. Der Aufsatz analysiert mit Hilfe diskurslinguistischer Methoden die Anstrengungen regionaler Institutionen und Medien, die nationale Vereinnahmung des historischen Gedenkens kritisch zu thematisieren sowie neue, zum eine lokal situierte, zum andern international orientierte Identifikationsangebote anzubieten. Die Analyse zeigt, dass solche „de-nationalisierten“ Identifikationsangebote zwar teilweise auch früher verwendet wurden, aber heutzutage rekontextualisiert und auf innovative Weise in den Vordergrund gestellt werden
Disruptions of Anaerobic Gut Bacteria Are Associated with Stroke and Post-stroke Infection : a Prospective Case-Control Study
In recent years, preclinical studies have illustrated the potential role of intestinal bacterial composition in the risk of stroke and post-stroke infections. The results of these studies suggest that bacteria capable of producing volatile metabolites, including trimethylamine-N-oxide (TMAO) and butyrate, play opposing, yet important roles in the cascade of events leading to stroke. However, no large-scale studies have been undertaken to determine the abundance of these bacterial communities in stroke patients and to assess the impact of disrupted compositions of the intestinal microbiota on patient outcomes. In this prospective case-control study, rectal swabs from 349 ischemic and hemorrhagic stroke patients (median age, 71 years; IQR: 67-75) were collected within 24 h of hospital admission. Samples were subjected to 16S rRNA amplicon sequencing and subsequently compared with samples obtained from 51 outpatient age- and sex-matched controls (median age, 72 years; IQR, 62-80) with similar cardiovascular risk profiles but without active signs of stroke. Plasma protein biomarkers were analyzed using a combination of nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Alpha and beta diversity analyses revealed higher disruption of intestinal communities during ischemic and hemorrhagic stroke compared with non-stroke matched control subjects. Additionally, we observed an enrichment of bacteria implicated in TMAO production and a loss of butyrate-producing bacteria. Stroke patients displayed two-fold lower plasma levels of TMAO than controls (median 1.97 vs 4.03 mu M, Wilcoxonp <0.0001). Finally, lower abundance of butyrate-producing bacteria within 24 h of hospital admission was an independent predictor of enhanced risk of post-stroke infection (odds ratio 0.77,p = 0.005), but not of mortality or functional patient outcome. In conclusion, aberrations in trimethylamine- and butyrate-producing gut bacteria are associated with stroke and stroke-associated infections.Peer reviewe
Modeling Phenotypic Heterogeneity of Glycogen Storage Disease Type 1a Liver Disease in Mice by Somatic CRISPR/CRISPR-associated protein 9-Mediated Gene Editing
BACKGROUND AND AIMS: Patients with glycogen storage disease type 1a (GSD‐1a) primarily present with life‐threatening hypoglycemia and display severe liver disease characterized by hepatomegaly. Despite strict dietary management, long‐term complications still occur, such as liver tumor development. Variations in residual glucose‐6‐phosphatase (G6PC1) activity likely contribute to phenotypic heterogeneity in biochemical symptoms and complications between patients. However, lack of insight into the relationship between G6PC1 activity and symptoms/complications and poor understanding of the underlying disease mechanisms pose major challenges to provide optimal health care and quality of life for GSD‐1a patients. Currently available GSD‐1a animal models are not suitable to systematically investigate the relationship between hepatic G6PC activity and phenotypic heterogeneity or the contribution of gene‐gene interactions (GGIs) in the liver. APPROACH AND RESULTS: To meet these needs, we generated and characterized a hepatocyte‐specific GSD‐1a mouse model using somatic CRISPR/CRISPR‐associated protein 9 (Cas9)–mediated gene editing. Hepatic G6pc editing reduced hepatic G6PC activity up to 98% and resulted in failure to thrive, fasting hypoglycemia, hypertriglyceridemia, hepatomegaly, hepatic steatosis (HS), and increased liver tumor incidence. This approach was furthermore successful in simultaneously modulating hepatic G6PC and carbohydrate response element‐binding protein, a transcription factor that is activated in GSD‐1a and protects against HS under these conditions. Importantly, it also allowed for the modeling of a spectrum of GSD‐1a phenotypes in terms of hepatic G6PC activity, fasting hypoglycemia, hypertriglyceridemia, hepatomegaly and HS. CONCLUSIONS: In conclusion, we show that somatic CRISPR/Cas9‐mediated gene editing allows for the modeling of a spectrum of hepatocyte‐borne GSD‐1a disease symptoms in mice and to efficiently study GGIs in the liver. This approach opens perspectives for translational research and will likely contribute to personalized treatments for GSD‐1a and other genetic liver diseases
Quantitative imaging of concentrated suspensions under flow
We review recent advances in imaging the flow of concentrated suspensions,
focussing on the use of confocal microscopy to obtain time-resolved information
on the single-particle level in these systems. After motivating the need for
quantitative (confocal) imaging in suspension rheology, we briefly describe the
particles, sample environments, microscopy tools and analysis algorithms needed
to perform this kind of experiments. The second part of the review focusses on
microscopic aspects of the flow of concentrated model hard-sphere-like
suspensions, and the relation to non-linear rheological phenomena such as
yielding, shear localization, wall slip and shear-induced ordering. Both
Brownian and non-Brownian systems will be described. We show how quantitative
imaging can improve our understanding of the connection between microscopic
dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of
methodology. Submitted for special volume 'High Solid Dispersions' ed. M.
Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009);
22 pages, 16 fig
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