Comparison of potential growth rates of Ceratium hirundinella with observed population density changes

Ceratium hirundinella cells in Lake Constance divided during the second half of the night. Growth rates are calculated from the fraction of cells undergoing cell division. Potential growth rates are compared with observed changes in population density. The discrepancy between both is discussed as a possible function of fungal parasitism

Quantitative evaluation of oligonucleotide surface concentrations using polymerization-based amplification

Quantitative evaluation of minimal polynucleotide concentrations has become a critical analysis among a myriad of applications found in molecular diagnostic technology. Development of high-throughput, nonenzymatic assays that are sensitive, quantitative and yet feasible for point-of-care testing are thus beneficial for routine implementation. Here, we develop a nonenzymatic method for quantifying surface concentrations of labeled DNA targets by coupling regulated amounts of polymer growth to complementary biomolecular binding on array-based biochips. Polymer film thickness measurements in the 20–220 nm range vary logarithmically with labeled DNA surface concentrations over two orders of magnitude with a lower limit of quantitation at 60 molecules/μm2 (∼106 target molecules). In an effort to develop this amplification method towards compatibility with fluorescence-based methods of characterization, incorporation of fluorescent nanoparticles into the polymer films is also evaluated. The resulting gains in fluorescent signal enable quantification using detection instrumentation amenable to point-of-care settings

The impact of glucose-insulin-potassium infusion in acute myocardial infarction on infarct size and left ventricular ejection fraction [ISRCTN56720616]

BACKGROUND: Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in acute myocardial infarction (MI). The mechanisms of this beneficial effect have not been delineated clearly. GIK has metabolic, anti-inflammatory and profibrinolytic effects and it may preserve the ischemic myocardium. We sought to assess the effect of GIK infusion on infarct size and left ventricular function, as part of a randomized controlled trial. METHODS: Patients (n = 940) treated for acute MI by primary percutaneous coronary intervention (PCI) were randomized to GIK infusion or no infusion. Endpoints were the creatinine kinase MB-fraction (CK-MB) and left ventricular ejection fraction (LVEF). CK-MB levels were determined 0, 2, 4, 6, 24, 48, 72 and 96 hours after admission and the LVEF was measured before discharge. RESULTS: There were no differences between the two groups in the time course or magnitude of CK-MB release: the peak CK-MB level was 249 ± 228 U/L in the GIK group and 240 ± 200 U/L in the control group (NS). The mean LVEF was 43.7 ± 11.0 % in the GIK group and 42.4 ± 11.7% in the control group (P = 0.12). A LVEF ≤ 30% was observed in 18% in the controls and in 12% of the GIK group (P = 0.01). CONCLUSION: Treatment with GIK has no effect on myocardial function as determined by LVEF and by the pattern or magnitude of enzyme release. However, left ventricular function was preserved in GIK treated patients

The #alpha#-effect in the Karlsruhe dynamo experiment

In order to obtain estimates of the self-excitation condition of the magnetic field in the experimental device and to give predictions on its geometrical structure, several calculations of the #alpha#-coefficients and related quantities have been carried out, and several kinematic mean-field dynamo models have been investigated (Raedler et al. 1996, 1997). After a few general explanations concerning the mean-field concept and the #alpha#-effect we will present and discuss here a few results on the #alpha#-coefficient. (orig.)7 refs.Available from TIB Hannover: RR 7310(97-10) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

On the mean-field theory of the Karlsruhe Dynamo Experiment

In the Forschungszentrum Karlsruhe an experiment has been constructed which demonstrates a homogeneous dynamo as is expected to exist in the Earth's interior. This experiment is discussed within the framework of mean-field dynamo theory. The main predictions of this theory are explained and compared with the experimental results. <br><br><b>Key words.</b> Dynamo, geodynamo, dynamo experiment, mean-field dynamo theory, <font face='Symbol'>a</font>-effec

The Karlsruhe dynamo experiment - a mean-field approach

In the Forschungszentrum Karlsruhe an experiment is under preparation in which, in view of the geodynamo and other cosmic dynamos, a homogeneous dynamo should be demonstrated and investigated. This experiment is discussed within the framework of mean-field dynamo theory. Results are presented concerning kinematic cylindrical mean-field dynamo models reflecting some features of the experimental device, as well as results of detailed calculations of the #alpha#-effect that apply to arbitrarily high magnetic Reynolds numbers. On this basis estimates of the excitation conditions of the dynamo are given and predictions concerning the geometrical structure of the generated magnetic fields are made. (orig.)Available from TIB Hannover: RR 7310(98-12) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman