Rapid development of tolerance to the hypothermic effect of ethanol in mice

The hypothermic response to i.p. injection of ethanol (2.0-4.0 g/kg) in mice was found to be attenuated by a single equivalent ethanol injection given 24 hr earlier. The diminished hypothermic response was not an artifact since it could not be attributed to changes in body weight and was independent of familiarity with test environment and procedures. A parallel shift in the dose-response curve was found. It appears, therefore, that the reduced change in body temperature is indicative of tolerance. If the second ethanol injection was given 48 or 72 hr later, tolerance could no longer be seen. With injections spaced 24 hr apart, a third administration of ethanol did not further increase the tolerance seen after the second injection. Since blood ethanol levels did not differ in tolerant and nontolerant mice, and since tolerance was already present 10 min after the second ethanol injection, a functional rather than a metabolic tolerance is likely.     

The effective velocity model: An improved approach to velocity sampling in actuator line models

Actuator line modeling of wind turbines requires the definition of a free-stream velocity in a computational mesh and a regularization kernel to project the computed body forces onto the domain. Both choices strongly influence the results. In this work, a novel velocity sampling method—the so-called effective velocity model (EVM)—is implemented in the CFD software SOWFA, validated, and compared to pre-existing approaches. Results show superior method robustness with respect to the regularization kernel width ( $ϵ$) choice while preserving acceptable accuracy. In particular, the power predicted by the EVM is nearly independent of the $ϵ$ value.     

Effects of grading procedures on the scatter of characteristic values of European grown sawn timber

The natural scatter in mechanical properties of sawn timber must be reduced by grading the material either visually or mechanically. Depending on the grading procedure, the scatter of these properties varies. This study deals with their variation as influenced by the grading procedure. The effect of the grading principle is analyzed based on 4,893 sawn timber specimens from several European natural forests with widths up to 167 mm and depths up to 284 mm and using the method given in EN 14081-2:2010, CEN, Brussels (2010). Grading models for visual grading and machine grading are derived considering different source countries, strength classes and strength class combinations. Material safety factors for the graded material are then estimated in accordance with ISO 2394 (1998) to evaluate the grading outcomes. Analyzing and comparing the lower 5th-percentile to the requirements of EN 384: 2009, CEN, Brussels (2009), it is found that the actual strength for class C24 can be up to 20 % lower than required by the standard. This is true, regardless of whether the timber is graded visually or by an advanced grading machine using dynamic modulus of elasticity and knots. Low strength values can be expected especially in cases where a batch of timber is graded into a single strength class and reject only. High coefficients of variation of the graded material lead to the conclusion that high material safety factors are needed. On the contrary, if the material is graded by a machine and into more than two strength classes in one pass, it can be shown that the required material safety factors can be lower.     

Clinical evaluation of ultra-high-field MRI for three-dimensional visualisation of tumour size in uveal melanoma patients,with direct relevance to treatment planning

Objectives

To assess the tumour dimensions in uveal melanoma patients using 7-T ocular MRI and compare these values with conventional ultrasound imaging to provide improved information for treatment options.

Materials and methods

Ten uveal melanoma patients were examined on a 7-T MRI system using a custom-built eye coil and dedicated 3D scan sequences to minimise eye-motion-induced image artefacts. The maximum tumour prominence was estimated from the three-dimensional images and compared with the standard clinical evaluation from 2D ultrasound images.

Results

The MRI protocols resulted in high-resolution motion-free images of the eye in which the tumour and surrounding tissues could clearly be discriminated. For eight of the ten patients the MR images showed a slightly different value of tumour prominence (average 1.0 mm difference) compared to the ultrasound measurements, which can be attributed to the oblique cuts through the tumour made by the ultrasound. For two of these patients the more accurate results from the MR images changed the treatment plan, with the smaller tumour dimensions making them eligible for eye-preserving therapy.

Conclusion

High-field ocular MRI can yield a more accurate measurement of the tumour dimensions than conventional ultrasound, which can result in significant changes in the prescribed treatment.

     

Structure-property relations in molded, nucleated isotactic polypropylene

The influence of molecular characteristics and nucleating agents on the morphology distribution and properties of injection molded isotactic polypropylene (iPP) is investigated using optical microscopy, X-ray diffraction and mechanical testing. To have better control over the thermo-mechanical history, instead of a reciprocating screw, a capillary rheometer is used to drive the melt into the simple rectangular mold. Molecular weight (MW), molecular weight distribution (MWD) and addition of ethylene via copolymerization all influence the thickness of the oriented shear layer, the crystallinity, the type and amount of crystal phases, and the lamellar thickness. The addition of a nucleating agent (DMDBS), dictates the crystallization process, and resulting morphology, and samples with an oriented morphology over the full thickness are created without changing other morphological features, by applying a thermal treatment to the melt prior to injection, which is based on the specific phase behavior of the iPP-DMDBS system. The thermally treated samples show a considerable improvement in mechanical properties.     

Influence of cross-section and knot assessment on the strength of visually graded Norway spruce

The strength of graded timber is determined by a multitude of parameters. Properties of interest are the shape of the cross-section and the wood quality. With regard to strength, wood quality is primarily expressed in terms of knots and knot clusters which, together with the cross-section of the timber, are used to calculate knot ratios. By applying the visual grading rules as given in the German standard DIN 4074-1, the influence of different timber sizes on grading results has been analysed. Different grading approaches for joists and boards exist and are taken into account in the assessment of 5,665 specimens originating from various parts of Europe. It was shown that both the cross-section and the grading method have a major influence on the characteristic strength values of Norway spruce. Limitations of the current standard with respect to its applicability to certain cross-sections are exposed. Alternative, simple grading approaches for boards are proposed. They ensure equal strength values and yields comparable to the rather complicated board rules used nowadays.     

The High-Resolution X-Ray Microcalorimeter Spectrometer, SXS, on Astro-H

The science and an overview of the Soft X-ray Spectrometer onboard the STRO-H mission are presented. The SXS consists of X-ray focusing mirrors and a microcalorimeter array and is developed by international collaboration lead by JAXA and NASA with European participation. The detector is a 6×6 format microcalorimeter array operated at a cryogenic temperature of 50 mK and covers a 3′×3′ field of view of the X-ray telescope of 5.6 m focal length. We expect an energy resolution better than 7 eV (FWHM, requirement) with a goal of 4 eV. The effective area of the instrument will be 225 cm² at 7 keV; by a factor of about two larger than that of the X-ray microcalorimeter on board Suzaku. One of the main scientific objectives of the SXS is to investigate turbulent and/or macroscopic motions of hot gas in clusters of galaxies.     

Referent Cognitions Theory: The role of closeness of reference points in the psychology of voice.

The most generally accepted and best documented manipulation in procedural justice experiments is varying whether or not participants are allowed an opportunity to voice their opinion about a decision. To better understand the psychology of voice, the authors focus on Referent Cognitions Theory (RCT). It is argued that thus far RCT has not been used to explain the psychology of voice and that previous RCT research suffers from methodological problems and has been more outcome oriented than necessary. Two experiments resolve these problems and show that people react more strongly to procedures (especially no-voice procedures) when reference points are close as opposed to distant. These findings suggest that closeness of reference points plays an important role in the psychology of voice. The findings expand RCT in significant ways and indicate that insight into the role of reference points is essential for understanding the psychology of justice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)