The use of 15N-labeled dietary proteins for determining true ileal amino acid digestibilities is limited by their rapid recycling in the endogenous secretions of pigs

We assessed the use of 15N-labeled dietary proteins as a possible tool for the determination of the true ileal amino acid (AA) digestibility in pigs. The first experiment was designed to study the dietary N excretion pattern at the ileum subsequent to the ingestion of a single 15N-labeled meal. In a second experiment, we compared ileal endogenous AA outputs and true AA digestibility estimates obtained in pigs ingesting 15N-labeled dietary proteins in a single meal vs. intravenous infusion of [15N]leucine for 10 d during the ingestion of a pea-based diet and a protein-free starch diet. The proportion of endogenous N found in the ileal digesta differed when the label was delivered orally (50%) vs. intravenously (72%) and changed with time. As a consequence, the true ileal AA digestibilities measured with labeled diets were lower. A third experiment demonstrated that this was due to the rapid recycling of labeled dietary N in endogenous moieties, because 15N was found in blood within 10 min of consuming the labeled meal, within 50 min of consumption in pancreatic enzymes, 90 min in bile and 4 h in ileal mucins. We conclude that the use of 15N-labeled meals for determination of true ileal AA digestibilities is limited by the fast recycling of dietary N in endogenous secretions following a single 15N-labeled meal. The accuracy of results will depend on meaningful estimates of AA flow during a limited period and accurate estimates of 15N in AA.     

Infrared spectra of poly(ethylene terephthalate) yarns. Fitting of spectra,evaluation of parameters,and applications

A quantitative model for fitting infrared spectra of polyethyleneterephthalate samples over the region from 1100 to 720 cm^?1 has been evaluated. The absorbance was described as the sum of a linear base line and a set of symmetrical bell-shaped Pearson VII curves. Using this model, experimental transmission spectra of yarns, measured with the electric vector parallel and perpendicular to the fiber axis, were fitted. It was found that each of the trans bands near 972 and 845 cm^?1 consists of two components, a narrow and a broad one. These two components represent the crystalline and amorphous phases respectively. The band due to the out of plane benzene ring C? H deformation vibration at about 875 cm^?1 appeared also to be composed of two contributions. In this case, the narrow component was found to be due to molecules having interactions with direct neighbors. So this narrow component not only contains the molecules in the crystalline phase but also those forming part of bundles which are too small to be detected by x-ray diffraction. For a detailed insight into the molecular arrangement of the amorphous regions, the infrared detection of trans-guache transitions, fold content, detection of bundlelike structures, and molecular stress on tie molecules turned out to be of great practical importance. The structural details, which can be revealed by the infrared technique, cannot be obtained by other means. The potential of the method is illustrated with some practical examples.     

Correct program parallelisations

International Journal on Software Tools for Technology Transfer - A commonly used approach to develop deterministic parallel programs is to augment a sequential program with compiler directives...     

VerifyThis 2015

VerifyThis 2015 was a one-day program verification competition which took place on April 12th, 2015 in London, UK, as part of the European Joint Conferences on Theory and Practice of Software (ETAPS 2015). It was the fourth instalment in the VerifyThis competition series. This article provides an overview of the VerifyThis 2015 event, the challenges that were posed during the competition, and a high-level overview of the solutions to these challenges. It concludes with the results of the competition and some ideas and thoughts for future instalments of VerifyThis.     

On the axiomatizability of priority II

This paper contributes to the study of the equational theory of the priority operator of Baeten, Bergstra and Klop in the setting of the process algebra BCCSP. It is shown that, in the presence of at least two actions, the collection of process equations over BCCSP with the priority operator that are valid modulo bisimilarity, irrespective of the chosen priority order over actions, is not finitely based. This holds true even if one restricts oneself to the collection of valid process equations that do not contain occurrences of process variables.     

A calculus for four-valued sequential logic

We present a complete axiomatisation for four-valued sequential logic. It consists of nine axioms, from which all valid laws can be derived by equational reasoning. These nine axioms are independent of each other.     

Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed.     

A silent shift? The precarisation of the Dutch rental housing market

The traditional Dutch rental contract is permanent (i.e. time unlimited), but there are indications that in recent years the number of temporary rental contracts has increased considerably. Dutch housing policy appears to be responding to this by pursuing deregulation of the conditions under which temporary rent is permitted. It is in this regard startling that there is no reliable data available about the size or character of the temporary sector, and it has thus far not attracted any scholarly attention. Given that temporary rent can be viewed as a form of precarisation, a transfer of risk to citizens, with corresponding negative effects on the lives of those involved, it is imperative to close this knowledge gap. This paper is a first attempt to do this. Firstly, I systematically review the scarce evidence that is currently available, and secondly, I explore why the rise of temporary rent has thus far failed to stimulate any social debate; it appears to constitute a silent precarisation that contrasts with the politically sensitive issue of labour precarisation. In doing so, I will identify the research questions that must be answered if the significance of this process for both tenants and wider welfare-state restructuring is to be fully understood.     

Performance and exergy analysis of biomass-to-fuel plants producing methanol,dimethylether or hydrogen

A desktop study has been performed to analyse the performance of biomass-to-fuel plants producing methanol, dimethylether (DME) or hydrogen. Two different designs have been made. One design based on the technology of today and one design based on the technology of tomorrow. Mass and energy balances are presented for both designs producing all three fuels. Biomass-to-fuel conversion efficiencies (LHV) of the plants range between 45 and 56% for hydrogen and DME production respectively in the present-day design and between 56 and 69% for hydrogen and methanol production respectively for the near-future design. Biomass-to-fuel conversion efficiency to DME is only marginally smaller than biomass-to-fuel conversion efficiency of methanol. Expression of efficiency of the biomass-to-fuel plant in biomass-to-fuel conversion efficiency does not include electrical power consumption and district heat generation. Exergy also includes the quality of the energy that is consumed or generated. Therefore exergetic efficiency should be used to express process efficiency. Methanol production using the technology of tomorrow is most efficient with exergetic efficiency of 55%. The least efficient is hydrogen production with exergetic efficiency of 40% and 45%, for present-day and near-future design, respectively. This is caused by the large purge stream in the plant design. The use of new technologies developed within the CHRISGAS project give an increase of 5–8% points in exergetic efficiency.