Search Results - (Author, Cooperation:G. W. Hart)

2013-10-01

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Acetylglucosamine/metabolism ; Animals ; Arrhythmias, Cardiac/complications/enzymology/*metabolism ; Benzylamines/pharmacology ; Brain/drug effects/enzymology ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 2/*metabolism ; Diabetes Complications/enzymology/*metabolism ; Diazooxonorleucine/pharmacology ; Enzyme Activation/drug effects ; Glucose/metabolism/pharmacology ; Glycosylation/drug effects ; Humans ; Hyperglycemia/complications/enzymology/*metabolism ; Mice ; Myocardium/cytology/enzymology ; Myocytes, Cardiac/enzymology/metabolism ; Rats ; Sarcoplasmic Reticulum/metabolism ; Sulfonamides/pharmacology

2016-03-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Acetylglucosamine/metabolism ; Animals ; Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism ; Energy Metabolism/genetics/*physiology ; Feeding Behavior/*physiology ; Gene Deletion ; Homeostasis/genetics ; Hyperphagia/*genetics ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; N-Acetylglucosaminyltransferases/genetics/*physiology ; Neurons/enzymology ; Obesity/genetics ; Paraventricular Hypothalamic Nucleus/cytology/enzymology/*physiology ; Protein Processing, Post-Translational ; Satiety Response/physiology

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

The use of the Lamb dip as a technique for precision spectroscopy in a non-neutral plasma is explored through computer modeling. Using singly ionized magnesium as the ion and under typical pure ion plasma conditions, the measurement appears to be feasible. Under the conditions calculated here, the Lamb dip is only 4% wider than the natural linewidth of the transition.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

A computer code has been developed which simulates a Thomson scattering measurement, from the counting statistics of the input channels through the mathematical analysis of the data. The scattered and background signals in each of the wavelength channels are assumed to obey Poisson statistics, and the spectral data are fitted to a Gaussian curve using a nonlinear least-squares fitting algorithm. This method goes beyond the usual calculation of the signal-to-noise ratio for the hardware and gives a quantitative measure of the effect of the noise on the final measurement. This method is applicable to Thomson scattering measurements in which the signal-to-noise ratio is low due to either low signal or high background. Thomson scattering data from the S-1 spheromak have been compared to this simulation, and they have been found to be in good agreement. This code has proven to be useful in assessing the effects of counting statistics relative to shot-to-shot variability in producing the observed spread in the data. It was also useful for designing improvements for the S-1 Thomson scattering system, and this method would be applicable to any measurement affected by counting statistics.

Electronic Resource

1089-7666

AIP Digital Archive

Physics

A linear perturbation expansion has been found that allows the rapid and accurate calculation of the response of a non-neutral plasma to a tilted magnetic field. The results of the calculation have been found to agree with previous three-dimensional equilibrium calculations, and also to agree with Keinigs' [Phys. Fluids 24, 860 (1981)] calculation of zero-frequency resonances caused by magnetic field errors. This expansion also allows the perturbed velocity to be calculated. It is speculated that this perturbed flow may be related to the enhanced radial transport in a non-neutral plasma with a tilted magnetic field.

Electronic Resource

1089-7666

AIP Digital Archive

Physics

Globally coherent modes have been observed during formation in the S-1 Spheromak plasma [Plasma Physics and Controlled Nuclear Fusion 1984 (IAEA, Vienna, Austria, 1985), Vol. 2, p. 535] by analysis of magnetic field fluctuations measured from outside the plasma. The modes are of low n number (2≤n≤5), where n is defined by the functional dependence einφ of the fluctuation on toroidal angle φ. These modes are shown to be related to flux conversion and plasma relaxation toward a minimum-energy state during the spheromak formation. The modes are active while the q profile is rapidly changing, with q on axis, q0, rising to 0.7. A significant finding is the temporal progression through the n=5, 4, 3, 2; m=1 mode sequence as q rises through rational fractions m/n. During formation, peak amplitudes of the n=2, 3, 4 modes relative to the unperturbed field have been observed as high as 20%, while more typical amplitudes are below 5%.

Electronic Resource

1089-7666

AIP Digital Archive

Physics

Experimental measurements of the equilibrium in the S-1 spheromak [M. Yamada, J. Sinnis, H. P. Furth, M. Okabayashi, G. Sheffield, T. H. Stix, and A. M. M. Todd, in Proceedings of the US-Japan Symposium on Compact Toruses and Energetic Particle Injection (Princeton Plasma Physics Laboratory, Princeton, NJ, 1979), p. 171] by use of magnetic probes inside the plasma show that the final magnetic equilibrium is one that has relaxed close to the Taylor (minimum-energy) state, even though the plasma is far from that state during formation. The comparison is made by calculating the two-dimensional μ profile of the plasma from the probe data, where μ is defined as μ0 j(parallel)/B. Measurements using a triple Langmuir probe proved evidence to support the conclusion that the pressure gradients in the relaxed state are confined to the edge region of the plasma.

Electronic Resource

1546-1718

Nature Archives 1869 - 2009

Biology

Medicine

[Auszug] Transcription of the 2.5 megabase dystrophin gene gives rise to multiple isoforms. We describe a 5.2 kilobase transcript, expressed specifically in peripheral nerve, that initiates at a previously unrecognized exon located ∼850 basepairs upstream of dystrophin exon 56. The likely product of ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] As part of our effort to develop more sensitive methods of dystrophin detection, we immunized rabbits with a fusion protein produced from a large segment of dystrophin rod domain. The resulting antibody (anti 6-10) is extremely sensitive, enabling low levels of dystrophin to be detected. Given ...

Electronic Resource

1432-0428

Keywords O-GlcNAc transferase, pancreas, streptozotocin, diabetes, immunohistochemistry, rat.

Springer Online Journal Archives 1860-2000

Medicine

Abstract Aims/hypothesis. Streptozotocin (STZ), a chemically reactive analogue of N-acetylglucosamine, induces necrosis of the beta cells, resulting in diabetes mellitus. Glucose-induced insulin resistance is mediated by increased activity of the hexosamine pathway. We aimed to examine the regulation of O-GlcNAc transferase expression and activity in the normal and streptozotocin diabetic pancreas.¶Methods. Rats were made diabetic by an injection of streptozotocin (65 mg/kg). The expression of O-GlcNAc transferase protein was examined by immunoblot analysis. Activity of O-GlcNAc transferase was assayed by the incorporation of [3H]GlcNAc into the synthetic peptide. Localization of O-GlcNAc transferase was done by immunohistochemistry. The change of O-GlcNAc modification of proteins was examined by immunoblot analysis.¶Results. In the STZ-induced diabetic pancreas, a severe loss of beta cells was observed, whereas alpha cells had increased in number. The diabetic pancreas showed an increase in the expression of O-GlcNAc transferase at the protein level and the O-GlcNAc transferase activity in it was increased significantly (p 〈 0.05). An increase in the immunostaining intensity in the cytoplasm of islet beta cells was also observed in the diabetic pancreas, whereas exocrine cells and islet cells other than beta cells showed little change in immunostaining intensity. The pancreas of STZ-diabetic rats showed a 3.1-fold increase in total cellular O-GlcNAc-modified proteins.¶Conclusion/interpretation. These findings indicate that O-GlcNAc transferase plays an important part in the modulation of O-GlcNAc concentrations in the pancreas and suggest that the increase in O-GlcNAc modification of the proteins correlates closely with diabetes. [Diabetologia (2000) 43: 1239–1247]

Electronic Resource

1573-4986

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource