Program for computing partial pressures from residual gas analyzer data

A computer program for determining the partial pressures of various gases from residual-gas-analyzer data is given. The analysis of the ion currents of 18 m/e spectrometer peaks allows the determination of 12 gases simultaneously. Comparison is made to ion-gage readings along with certain other control information. The output data are presented in both tabular and graphical form

Cellular mRNAs access second ORFs using a novel amino acid sequence-dependent coupled translation termination-reinitiation mechanism

Polycistronic transcripts are considered rare in the human genome. Initiation of translation of internal ORFs of eukaryotic genes has been shown to use either leaky scanning or highly structured IRES regions to access initiation codons. Studies on mammalian viruses identified a mechanism of coupled translation termination-reinitiation that allows translation of an additional ORF. Here, the ribosome terminating translation of ORF-1 translocates upstream to reinitiate translation of ORF-2. We have devised an algorithm to identify mRNAs in the human transcriptome in which the major ORF-1 overlaps a second ORF capable of encoding a product of at least 50 aa in length. This identified 4368 transcripts representing 2214 genes. We investigated 24 transcripts, 22 of which were shown to express a protein from ORF-2 highlighting that 3' UTRs contain protein-coding potential more frequently than previously suspected. Five transcripts accessed ORF-2 using a process of coupled translation termination-reinitiation. Analysis of one transcript, encoding the CASQ2 protein, showed that the mechanism by which the coupling process of the cellular mRNAs was achieved was novel. This process was not directed by the mRNA sequence but required an aspartate-rich repeat region at the carboxyl terminus of the terminating ORF-1 protein. Introduction of wobble mutations for the aspartate codon had no effect, whereas replacing aspartate for glutamate repeats eliminated translational coupling. This is the first description of a coordinated expression of two proteins from cellular mRNAs using a coupled translation termination-reinitiation process and is the first example of such a process being determined at the amino acid level

What do patients really know? An evaluation of patients’ physical activity guideline knowledge within general practice

Background: Physical inactivity is well recognised as one of the leading causes of preventable death. However, little is known about the general public’s knowledge surrounding national physical activity guidelines, particularly within general practice (GP). Setting: Two GPs (York and Maidenhead, UK). Question: Are GP patients aware of the national physical guidelines? Also, are health care professionals routinely raising the issue of physical inactivity and would patients welcome support from health care professionals regarding inactivity? Methodology: A questionnaire was distributed in two GPs over a one-week period to evaluate patients knowledge of the national physical activity guidelines. Results: Ninety-four participants completed the questionnaire over one week (60 female; 34 male), with an average age of 54.2 (standard deviation: 19.9 years). 14% (95% Confidence Interval (CI): 8–22%) of the total participants correctly knew the recommended national guidelines for physical activity. 52% (95% CI: 42–63%) recalled being asked by a health care professional about their activity levels. 46% (95% CI: 35–56%) would welcome support from a health care professional around improving their activity levels. Discussion/Conclusion: Only 14% of responders correctly knew the current national minimum activity guidelines. Encouragingly 46% of participants in our study were interested in physical activity advice from a health care professional. Health care professionals need to be aware that many patients do not know the current physical activity guidelines and recognise that primary care may be an underutilised opportunity to educate and promote physical activity

Heteroclinic intersections between Invariant Circles of Volume-Preserving Maps

We develop a Melnikov method for volume-preserving maps with codimension one invariant manifolds. The Melnikov function is shown to be related to the flux of the perturbation through the unperturbed invariant surface. As an example, we compute the Melnikov function for a perturbation of a three-dimensional map that has a heteroclinic connection between a pair of invariant circles. The intersection curves of the manifolds are shown to undergo bifurcations in homologyComment: LaTex with 10 eps figure

Residual stress generation in tungsten-copper brazed joint using brazing alloy

Understanding the residual stress state in brazed joints is crucial for operational design and life time performance of the part in service. High magnitudes residual stresses are expected in the joined materials following cooling from brazing temperatures (≈950°C) due to large mismatches in material properties such as coefficient of thermal expansion and Young’s modulus. This study aims at further understanding of the generation and distribution of residual stresses when brazing tungsten to copper using a eutectic gold-copper brazing alloy. This configuration is potentially useful for future divertor designs. Finite Element Analysis (FEM) has been used to predict the brazing induced stresses and residual stress measurements were carried out on the brazed joint by X-ray diffraction (XRD) to validate the prediction model. Large residual stresses are predicted and measured in the tungsten; however there is disagreement in the sign of the stress. Predicted stresses are highly tensile in nature close to the brazing interface, whereas the measured stresses are highly compressive. The disagreement is believed to be caused by the model not accurately simulating the complex brazing process. Residual stress measurements on the copper were not possible due to texturing during brazing, grain growth and significant inelastic strains and deformations. Misalignment of parent materials was also observed to significantly affect residual stresses

Residual stress generations in brazed tungsten dissimilar joints

Understanding the residual stress state in brazed joints is crucial for the operational design and lifetime performance of the part in service. High-magnitude residual stresses are expected in the joined materials following cooling from brazing temperatures (≈950 °C) due to large mismatches in the thermal and mechanical properties. This paper aims at further understanding of the residual stresses caused when brazing tungsten to copper and tungsten to 316L austenitic steel using a eutectic gold-copper brazing alloy. These configurations are potentially useful for future diverter designs. Finite element analysis has been used to predict the brazing-induced stresses and residual stress measurements were carried out on the brazed joint by X-ray diffraction to validate the prediction model. Large residual stresses are predicted and measured in the tungsten; however, there is disagreement in the nature of the stress in the tungsten-copper configuration. Predicted stresses are highly tensile in nature close to the brazing interface, whereas the measured stresses are highly compressive. The disagreement is believed to be caused by the model not accurately simulating the complex brazing process. Residual stress measurements on the copper were not possible due to texturing during brazing, grain growth, and significant inelastic strains. There is excellent correlation between the measured and predicted stresses in the tungsten-316L configuration. High-tensile stresses were predicted in the tungsten (magnitude approximately 1000 MPa close to the braze interface) and high tensile stresses were measured (magnitude approximately 800 MPa in the same region). Joint misalignment of parent materials was also observed to significantly affect the residual stresses

A 2.75-Approximation Algorithm for the Unconstrained Traveling Tournament Problem

A 2.75-approximation algorithm is proposed for the unconstrained traveling tournament problem, which is a variant of the traveling tournament problem. For the unconstrained traveling tournament problem, this is the first proposal of an approximation algorithm with a constant approximation ratio. In addition, the proposed algorithm yields a solution that meets both the no-repeater and mirrored constraints. Computational experiments show that the algorithm generates solutions of good quality.Comment: 12 pages, 1 figur

Higher and lower supramolecular orders for the design of self-assembled heterochiral tripeptide hydrogel biomaterials

The self-assembly behaviour of the eight stereoisomers of Val\u2013Phe\u2013Phe tripeptides under physiological conditions is assessed by several spectroscopy and microscopy techniques. We report the first examples of self-organised hydrogels from tripeptides in the L\u2013D\u2013L or D\u2013L\u2013D configuration, besides the expected gels with the D\u2013L\u2013L or L\u2013D\u2013D configuration, thus widening the scope for using amino acid chirality as a tool to drive self-assembly. Importantly, the positions of D- and L-amino acids in the gelling tripeptides determine a higher or lower supramolecular order, which translates into macroscopic gels with different rheological properties and thermal behaviours. The more durable hydrogels perform well in cytotoxicity assays, and also as peptides in solution. An appropriate design of the chirality of self-assembling sequences thus allows for the fine-tuning of the properties of the gel biomaterials. In conclusion, this study adds key details of supramolecular organization that will assist in the ex novo design of assembling chiral small molecules for their use as biomaterials

Design of a hydrophobic tripeptide that self-assembles into amphiphilic superstructures forming a hydrogel biomaterial

We report the rational design of a heterochiral hydrophobic tripeptide self-assembling into amphiphilic D-superstructures that yield a self-supportive hydrogel at physiological pH. The material endures cell culture conditions and sustains fibroblast proliferation. Tripeptide superstructures are thoroughly analysed by several techniques

What do patients really know? An evaluation of patients’ physical activity guideline knowledge within general practice

Background: Physical inactivity is well recognised as one of the leading causes of preventable death. However, little is known about the general public’s knowledge surrounding national physical activity guidelines, particularly within general practice (GP). Setting: Two GPs (York and Maidenhead, UK). Question: Are GP patients aware of the national physical guidelines? Also, are health care professionals routinely raising the issue of physical inactivity and would patients welcome support from health care professionals regarding inactivity? Methodology: A questionnaire was distributed in two GPs over a one-week period to evaluate patients knowledge of the national physical activity guidelines. Results: Ninety-four participants completed the questionnaire over one week (60 female; 34 male), with an average age of 54.2 (standard deviation: 19.9 years). 14% (95% Confidence Interval (CI): 8–22%) of the total participants correctly knew the recommended national guidelines for physical activity. 52% (95% CI: 42–63%) recalled being asked by a health care professional about their activity levels. 46% (95% CI: 35–56%) would welcome support from a health care professional around improving their activity levels. Discussion/Conclusion: Only 14% of responders correctly knew the current national minimum activity guidelines. Encouragingly 46% of participants in our study were interested in physical activity advice from a health care professional. Health care professionals need to be aware that many patients do not know the current physical activity guidelines and recognise that primary care may be an underutilised opportunity to educate and promote physical activity