Biochemical Investigation of the Interaction of pICln,RioK1 and COPR5 with the PRMT5–MEP50 Complex

The PRMT5–MEP50 methyltransferase complex plays a key role in various cancers and is regulated by different protein–protein interactions. Several proteins have been reported to act as adaptor proteins that recruit substrate proteins to the active site of PRMT5 for the methylation of arginine residues. To define the interaction between these adaptor proteins and PRMT5, we employed peptide truncation and mutation studies and prepared truncated protein constructs. We report the characterisation of the interface between the TIM barrel of PRMT5 and the adaptor proteins pICln, RioK1 and COPR5, and identify the consensus amino acid sequence GQF[D/E]DA[E/D] involved in binding. Protein crystallography revealed that the RioK1 derived peptide interacts with a novel PPI site.     

Solving Non-Linear Models with Saddle-Path Instabilities

Economic models derived from optimizing behavior are typically characterized by the properties of non-linearity and saddle-path instability. The typical solution method involves deriving the stable arm of the saddle-path and calculating suitable “jumps” to bring the path of endogenous variables onto this stable arm. The solution for the stable arm can be determined using a range of different approaches. In this paper we examine the extent to which the success of these alternative approaches can be evaluated. Any method of evaluation will be dependent upon the amount of information that is known about a particular model solution. For some deterministic models the only information known with certainty about the path of the model solution are values taken by steady-state solutions; the rest of the path must be approximated in some way based on numerical solutions derived from non-linear ordinary differential equations. In some special cases it is possible to derive a closed-form solution of the entire path. As an example of a model with a closed-form solution, we consider a simple linear model with two stable complex-valued eigenvalues and one unstable real-valued eigenvalue. The model is then employed as a benchmark to compare the properties of model solutions derived using two well-known solution algorithms. Because the model has complex-valued eigenvalues it will have cyclic dynamics and thus problems encountered in solving these dynamics will likely coincide with some of the problems that solution algorithms have in solving non-linear models. Since the entire solution path of the model is known, it is possible to derive deeper insights into the factors that are likely to ensure the success or failure of different solution approaches than would be the case if less information about the solution path was available.An earlier version of this paper was presented to the Ninth International Conference on Computing in Economics and Finance organized by the Society of Computational Economics, University of Washington at Seattle, July 11–13, 2003. Earlier versions of this paper have also been presented at seminars and workshops at the University of Oxford, at the University of Canterbury at Christchurch, and at the University of Melbourne. JEL Classifications: C63, E17     

Sampling improvements in atomic absorption spectroscopy

Atomic absorption spectroscopy is being used as a routein method to determine sodium, potassium, calcium, magnesium, copper and many other metallic elements in oils, fats, milk and other substances. Copper and iron can be measured directly in milk without sample preparation. When highly acidified samples are run, a new plastic-lined nebulizer is useful to prevent spurious results due to corrosion. A new sampling device, the Graphite Furnace, can analyze extremely small samples and gives detection limits in the picogram (10⁻¹² g) range. One of 28 papers presented at the Symposium, “Metal-Catalyzed Lipid Oxidation,” ISF-AOCS World Congress, Chicago, September 1970.     

Preparation and properties of phenolated phenanthrene-formaldehyde resins

Phenanthrene-formaldehyde resins of different oxygen content were reacted with phenol 110°C in the presence of a strong acid catalyst. Cleavage occurred at the dimethylene ether and acetal bridges joining the aromatic nuclei with the concomitant formation of phenanthrene-formaldehyde-phenol resins. These resins were characterised by gel permeation chromatography, ¹H n.m.r. and infrared spectroscopy.     

Stress analysis of a pressurized circular hole with radial cracks in an infinite elastic plate

The stresses are evaluated for the plane problem of radial cracks originating at the boundary surface of a pressurized, circular hole in an infinite elastic plate. The stress distribution is approximately equal to that around a pressurized and unfractured equivalent cavity, the radius of which is equal to that of the crack tips. The critical pressure at which brittle failure will occur is analyzed for several variations of the hole and crack geometry.

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Zusammenfassung Für das ebene Problem einer unter Innendruck gesetzten kreisförmigen Öffnung mit radialen Rissen in einer unendlich großen, elastischen Platte werden die Spannungen berechnet. Die Spannungsverteilung kann als Näherung der einer ebenfalls unter Innendruck gesetzten und nicht mit Rissen versehenen Kreisöffnung, deren Radius so groß wie der der Rißspitzen ist, gleichgesetzt werden. Der kritische Druck, bei dem es zum Sprödbruch kommt, wird für einige Variationen der Öfnungs und Rißgeometrie ermittelt.

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Résumé On évalue les contraintes dans le cas plan de fissures radiales prenant naissance à la surface intérieure d'un trou circulaire dans une plaque infinie et élastique, soumis à une pression uniforme.La distribution des contraintes est sensiblement égale à celle que l'on rencontre dans le cas d'une cavité équivalente soumise à pression et dépourvue de ruptures, dont le rayon est égal à celui des extrémités des fissures.La pression critique à laquelle se produira une rupture fragile fait l'objet d'une analyse dans plusieurs cas de géométries du trou et des fissures preéxistantes.

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Taken from a dissertation presented in partial fulfillment of the requirements for a Ph. D. in Mineral Engineering to the School of Mineral and Metallurgical Engineering, University of Minnesota, Minneapolis, Minn.