Some changes in the constituents upon heating a model meat flavour system

Percentage changes in the amino acid content upon heating with different components in a synthetic model meat flavour mixture were followed during different stages in development of the system. Heating of ten different amino acids with a simple sugar mixture (glucose, ribose and xylose) resulted in losses of approximately 95, 58, 38 and 37% of the cysteine, methionine, leucine and isoleucine, respectively, whereas the other amino acids decreased by 19–31%, but the ammonia (NH₃) content by only 5%. On heating gelatin with the simple sugar mixture, tyrosine and phenylalanine losses amounted to about 58 and 40%, respectively, while the other amino acids declined by 27–37% and the NH₃ content by some 12%. Heating of the composite model system (gelatin, added amino acids and simple sugars) resulted in losses of about 94, 60 and 55% of the cysteine, methionine and histidine, respectively, while the other amino acids decreased by 20–35% and the NH₃ content by 15%. The possible role of some of the amino acids in the development of the synthetic meat flavour system is discussed in view of these findings.     

Development of a coupled reactor model for prediction of organic contaminant fate in landfills

Models describing the behavior of organic chemicals in landfills can be useful to predict their fate and transport and also to generate input data for estimates of exposure and risk. The landfill coupled-reactor (LFCR) model developed in this work simulates a landfill as a series of fully mixed reactors, each representing a daily volume of waste. The LFCR model is a numerical model allowing time-variable input parameters such as gas generation, and cover type and thickness. The model was applied to three volatile organic chemicals (acetone, toluene, benzene) as well as naphthalene and the chemical warfare agent sarin under three landfill conditions (conventional, arid, bioreactor). Sarin was rapidly hydrolyzed, whereas naphthalene was largely associated with the landfill solid phase in all scenarios. Although similar biodegradation rates were used for acetone and toluene, toluene was more persistent in the landfill due to its hydrophobicity. The cover soil moisture content had a significant impact on gaseous diffusive losses.     

The effect of styrene grafting on the diffusion and solubility of organic liquids in polyethylene

The effect of grafting styrene onto low-density polyethylene on the diffusion and solubility of benzene and n-hexane in the graft copolymer has been investigated. The diffusion coefficient at zero concentration D_{c = 0} for both benzene and n-hexane decreased with the amount of styrene grafting in the polyethylene–styrene graft copolymer membrane. The free volume parameters of the polyethylene–styrene graft copolymer were calculated using benzene and n-hexane as the diffusing species. Results show that there is a large decrease in free volume as grafting proceeds and the effect is more pronounced at low levels of grafting. Solubility was found to be a function of the per cent grafting, there being a 50%–90% increase in benzene solubility in a 26% graft compared to polyethylene. The increase in solubility for n-hexane was considerably lower. The effect of crystallinity on the free volume parameters has also been calculated.     

Mass spectrometric differentiation of linear peptides composed of L-amino acids from isomers containing one D-amino acid residue

MS/MS of electrosprayed ions is shown to have the capacity to discriminate between peptides that differ by configuration about their alpha-carbons. It is not necessary for the peptides to possess tertiary structures that are affected by stereochemistry, since five epimers of the pentapeptide, H2N-Gly-Leu-Ser-Phe-Ala-OH (GLSFA) all display different collisionally activated dissociation (CAD) patterns of their protonated parent ions. The figure of merit, r, is a ratio of ratios of fragment ion abundances between stereoisomers, where r = 1 corresponds to no stereochemical effect. Values of r as high as 3.8 are seen for diastereomer pairs. Stereochemical effects are also seen for the diprotonated dodecapeptide H2N-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-OH (LVFFAEDVGSNK), a tryptic fragment from the amyloid beta-protein. Triply charged complexes of the protonated dodecapeptide with cobalt(II) ions undergo CAD at lower collision energies than do doubly protonated LVFFAEDVGSNK ions. Statistically significant (p < 0.01) differences between the all-L-dodecapeptide and the ones containing a d-serine or a D-aspartic acid are observed.     

5 bit, silicon-based, X-band phase shifter using a hybrid pi/t high-pass/low-pass topology

A hybrid pi/t bit passive topology is presented to enable a significant reduction in the die area for a high-pass/low-pass phase shifter is presented. A hybrid-topology 5 bit digital X-band phase shifter was designed, fabricated and tested using a 200 GHz, 0.13 mum SiGe bipolar complementary metal oxide semiconductor (BiCMOS) technology. Size and performance characteristics are presented as a contrast to an all-pi phase shifter recently presented by Comeau et al. using the same SiGe BiCMOS technology and design goals. With similar bit passive performance to the all-pi design, the hybrid shifter allows for a total shifter die-area reduction of 50.5%. The absolute phase error of the shifter was less than plusmn13 from 8 to 12 GHz, with an average insertion loss of -20 dB.     

Usability assessment of text-to-speech synthesis for additional detail in an automated telephone banking system

This paper describes a comprehensive usability evaluation of an automated telephone banking system which employs text-to-speech (TTS) synthesis in offering additional detail on customers’ account transactions. The paper describes a series of four experiments in which TTS was employed to offer an extra level of detail to recent transactions listings within an established banking service which otherwise uses recorded speech from a professional recording artist. Results from the experiments show that participants welcome the added value of TTS in being able to provide additional detail on their account transactions, but that TTS should be used minimally in the service.     

Dynamics of support perceptions among couples coping with cardiac illness: The effect on recovery outcomes.

Objective: The current prospective study explored how male cardiac patients' perceptions of received support (i.e., active engagement, protective buffering, and overprotection) moderated the associations between female partners' perceptions of provided support and patients' recovery outcomes: psychological well-being, cholesterol levels, and smoking cessation. Methods: Couples (N = 86) completed surveys at the initial hospitalization after patients' Acute Coronary Syndrome (ACS), and 1 and 6 months later. Partners' ways of providing support and patients' concurrent perceptions of these ways were measured using the Ways of Giving Support Questionnaire; patients' depressive and anxiety symptoms were measured using the Brief Symptom Inventory (BSI). Patients' cholesterol levels were assessed during hospitalization and 6 months later, and smoking habits were reported by the patients. Results: Female partners' protective buffering was positively associated with male patients' depressive symptoms at follow-up only when male patients' own perceptions of partners' protective buffering were low. Female partners' active engagement was positively associated with better odds for male patients' cessation of smoking only when patients' own perceptions of partners' active engagement were high. Finally, female partners' overprotection was associated with higher levels of male patients' harmful blood lipids at follow-up, but only when patients' own perceptions of partners' overprotection were high. Conclusions: As hypothesized, the effect of partners' perceptions of support provided on patients' recovery was moderated by patients' own perceptions of the support received. The effect of this interaction was determined by the specific types of support provided or received and by the specific recovery outcome that was measured. The clinical and theoretical implications of the findings are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The relationship between religious expression and outcomes in online support groups: A partial replication

Shaw and his colleagues [Shaw, B., Han, J., Kim, E., Gustafson, D., Hawkins, R., Cleary, C., et al. (2007). Effects of prayer and religious expression within computer support groups on women with breast cancer. Psycho-oncology, 16(7), 676–687] examined religious expression in breast cancer (BC) online support groups (OSG). Using Pennebaker’s LIWC text analysis to assess religious expression, they found that the more frequent the expression of words related to religion the lower the levels of negative emotions and the higher the levels of health self-efficacy and functional well-being. Our study goal was to replicate their findings. Specifically, we tested their central hypothesis that the percentage of religious words written by members of BC OSG’s are associated with improvement in psychological outcomes. Five BC OSG’s from our previous work [Lieberman, M. A., & Goldstein, B. (2005a). Not all negative emotions are equal: The role of emotional expression in online support groups for women with breast cancer. Psycho-oncology. 15, 160–168; Lieberman, M. A., & Goldstein, B. (2005b). Self-help online: An outcome evaluation of breast cancer bulletin boards. Journal of Health Psychology, 10(6), 855–862] studied 91 participants at baseline and 6 months post. Significant changes in depression and quality of life was found over time. In the current study linear regressions examined the relationship between religious statements and outcomes. The results did not support the hypotheses of a positive relationship between religious expression and positive outcome in both OSG samples. Reviews of studies examining the role of religion in health outcomes report equivocal results on the benefits of religious expression.