Diagnostics of accelerating plasma Semiannual progress report, 1 Mar. - 31 Aug. 1968

Plasma diagnostics in electromagnetically driven shock tubes using laser scattering methods as compared to spectroscopic technique

Exchange coupling between two ferromagnetic electrodes separated by a graphene nanoribbon

In this study, based on the self-energy method and the total energy calculation, the indirect exchange coupling between two semi-infinite ferromagnetic strips (FM electrodes) separated by metallic graphene nanoribbons (GNRs) is investigated. In order to form a FM/GNR/FM junction, a graphitic region of finite length is coupled to the FM electrodes along graphitic zigzag or armchair interfaces of width $N$. The numerical results show that, the exchange coupling strength which can be obtained from the difference between the total energies of electrons in the ferromagnetic and antiferromagnetic couplings, has an oscillatory behavior, and depends on the Fermi energy and the length of the central region.Comment: 4 pages, 6 figures, International Conference on Theoretical Physics 'Dubna-Nano2008

Selection of reference genes for qRT-PCR examination of wild populations of Atlantic cod Gadus morhua

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Symmetry, singularities and integrability in complex dynamics III: approximate symmetries and invariants

The different natures of approximate symmetries and their corresponding first integrals/invariants are delineated in the contexts of both Lie symmetries of ordinary differential equations and Noether symmetries of the Action Integral. Particular note is taken of the effect of taking higher orders of the perturbation parameter. Approximate symmetries of approximate first integrals/invariants and the problems of calculating them using the Lie method are considered

Do anesthetics and sampling strategies affect transcription analysis of fish tissues?

<p>Abstract</p> <p>Background</p> <p>The aim of the current examination was to evaluate if sedation and anesthetic treatment techniques affect the quality of RNA extracted from liver, gill, head kidney and brain tissues in Atlantic salmon <it>Salmo salar </it>L. Blood parameters were measured and tissue specimens sampled in six groups of fish; one control group (0 minutes), two groups kept in pure seawater in 90 liter tanks for 30 and 120 minutes, two groups treated with the anesthetic isoeugenol for 30 and 120 minutes, and one group kept in pure seawater for 105 minutes and then anaesthetized with metacaine for 15 minutes. RNA quality was assessed with the NanoDrop ND-1000 spectrophotometer (260/280 and 260/230 nm ratios) and with the Agilent Bioanalyzer (28S/18S ratio and RIN data) in samples either preserved in liquefied nitrogen (N₂) or in RNA<it>later</it>. In addition, the transcriptional levels of two fast-responding genes were quantified in gill and brain tissues.</p> <p>Results</p> <p>The results show that physiological stress during sampling does not affect the quality of RNA extracted from fish specimens. However, prolonged sedation (2 hours) resulted in a metabolic alkalosis that again affected the transcriptional levels of genes involved in ionoregulation and respiration. In gills, <it>Na</it>⁺-<it>K</it>⁺-<it>ATPase α1b </it>was significantly downregulated and <it>hypoxia inducible factor 1 </it>(<it>HIF1</it>) significantly upregulated after two hours of treatment with isoeugenol, suggesting that this commonly used sedative affects osmo-regulation and respiration in the fish. The results also suggest that for tissue preservation in general it is better to flash-freeze fish specimens in liquefied N₂than to use RNA<it>later</it>.</p> <p>Conclusion</p> <p>Prolonged sedation may affect the transcription of fast-responding genes in tissues of fish. Two hours of sedation with isoeugenol resulted in downregulation of the <it>Na</it>⁺-<it>K</it>⁺-<it>ATPase α1b </it>gene and upregulation of the <it>HIF1 </it>gene in gills of Atlantic salmon. The quality of RNA extracted from tissue specimens, however, was not affected by sedation treatment. Flash-freezing of tissue specimens seems to be the preferred preservation technique, when sampling fish tissue specimens for RNA extraction.</p

AC and DC House Wiring Efficiency Estimations Using a Fast Extensive Measurements Approach

DC-based appliances are exponentially increasing in the present market. This scenario opens the opportunity to utilize the DC electricity produced by the PV panels directly without going through the conversion stages. Due to high penetration of DC electricity sources, it is timely to utilize DC electricity directly. Several research works have been reported in the literature to experimentally test and compare AC and DC wiring options. Accurate and precise experimental measurements are vital to establish a sound theoretical basis. However, this is difficult due to cost and time constraints. Therefore, to avoid costly measurements, this paper develops a mathematical model based on measurements on selected AC and DC wiring at four voltage levels (12 V DC, 24 V DC, 48 V DC, and 230 V AC). A digital simulation calibration using DigSilent is conducted to validate the proposed mathematical model. This paper proposed to utilize the simulation calibration approach that is a cost-effective and timesaving option to perform extensive measurements accurately

Spatial transcription of CYP1A in fish liver

<p>Abstract</p> <p>Background</p> <p>The aim of this work was to study how evenly detoxifying genes are transcribed spatially in liver tissue of fish. Ten Atlantic salmon <it>Salmo salar </it>were intraperitoneally injected with 50 mg/kg of the strong CYP1A inducer β-naphthoflavone and liver tissue harvested seven days later. The liver from 10 control and 10 exposed fish were split into eight sections, RNA extracted and three reference (β-actin, elongation factor 1A_B(EF1A_B)) and two detoxifying genes (CYP1A and GST) quantified with real-time RT-PCR. The cellular localization of the EF1A_Band CYP1A mRNA in the liver of control and β-naphthoflavone treated fish was then determined by <it>in situ </it>hybridization (ISH) using EF1A_Band CYP1A biotinylated oligonucleotide probes.</p> <p>Results</p> <p>The study shows that genes encoding phase I and phase II conjugating enzymes are unevenly transcribed in different parts of the liver of Atlantic salmon seven days after a single-dose of β-naphthoflavone exposure. Transcription of CYP1A and GST was higher in the middle section of the liver compared to the distal and proximal parts of the organ. The ISH data suggest that CYP1A transcription happens mainly in hepatocyte cells in the liver, and that hepatocytes in the vicinity of blood vessels respond stronger to β-naphthoflavone than cells further away from the blood supply.</p> <p>Conclusion</p> <p>Overall, the qRT-PCR and ISH results reported here suggest that gene expression analysis should be performed on as pure cell populations as possible. If bulk tissue samples are to be used, one should always check how evenly the target genes are expressed in tissue sections and organs in every study.</p

Approach for Diagnostic and Treatment of Achalasia

Achalasia is a rare motor disorder of the esophagus and lower esophageal sphincter. The incidence is approximately 1/100,000 per year and the prevalence rate is 10/100,000. Achalasia is quite difficult to establishbecause the symptoms might be insidious and therefore not many people come to seek medical attention until it deteriorates to final stage of the disease. There are several modalities that can be used as diagnostic toolssuch as manometry, barium esophagogram, esophagoduodenoscopy, esophageal CT-scan, until the recent one, high-resolution manometry that can classify achalasia into three different types. The treatment options are the pharmacologic intervention, endoscopic treatment, minimal invasive surgery, and radical surgery.We reported a case of 20 year old female with achalasia who came with dysphagia symptom since three years before. The diagnosis was made by historytaking, physical examination and barium meal and esophagogastroduodenoscopy. The patient underwent pneumatic dilatation and since then the symptom was relieved

Deformation of Quantum Dots in the Coulomb Blockade Regime

We extend the theory of Coulomb blockade oscillations to quantum dots which are deformed by the confining potential. We show that shape deformations can generate sequences of conductance resonances which carry the same internal wavefunction. This fact may cause strong correlations of neighboring conductance peaks. We demonstrate the relevance of our results for the interpretation of recent experiments on semiconductor quantum dots.Comment: 4 pages, Revtex, 4 postscript figure