Classification of South African red and white wines according to grape variety based on the non-coloured phenolic content

The phenolic content of South African wines was investigated for the purpose of their classification according to variety or cultivar. Twenty-two phenolic compounds were quantified by liquid chromatography in 55 red wines of five varieties and in 38 white wines of three varieties. Data were compared to literature values reported for wines from across the globe. ANOVA was used to determine significant concentration differences between the different varieties. Further grouping of the data was investigated by principal component analysis and cluster analysis. Finally, linear discriminant analysis was used to derive classification functions for the effective recognition of red and white wine varieties which allowed 100.0% and 97.4% correct recognition of red and white wines, respectively.     

Phenotypic and genetic effects of season on milk production traits in dairy cattle in the Netherlands

Milk production systems in several countries show considerable differences between seasons. For example, in the Netherlands, cows are kept inside and fed silage in winter, whereas they are on pasture in summer. The differences between seasons affect milk yield and composition and might influence the genetic background of milk production traits. The objective of this study was to estimate phenotypic and genetic effects of season on milk production traits. For this purpose, 19,286 test-day milk production records of 1,800 first-parity Dutch Holstein-Frisian cows were available, and these cows were genotyped using a 50K SNP panel. Phenotypic effects of season were significant for all milk production traits. Effects of season were large for milk fat yield, fat content, and protein content. Genetic correlations between milk production traits in different seasons showed that genotype by season interaction effects were relatively small for most milk production traits. The genetic background of protein content and lactose content seems to be sensitive to seasonal effects. Furthermore, the genetic correlations between spring and autumn differed significantly from unity for almost all milk production traits. A genome-wide association study for genotype by season interaction identified chromosomal regions on BTA3, BTA14, BTA20, and BTA25 that showed genotype by season interaction effects, including a region containing DGAT1, which showed interaction effects for fat content and protein content.     

Antibiotic use and potential economic impact of implementing selective dry cow therapy in large US dairies

In this study, our objectives were to evaluate the economic feasibility of implementing selective dry cow therapy (SDCT) in large US herds and to estimate the potential reduction in antibiotic use around the dry period if SDCT management is adopted. Cow-level data were obtained from the Dairy Herd Improvement Association (AgriTech, Visalia, CA) and individual dairy herds in California. Logistic regression models were used to predict the incidence risk of subclinical and clinical mastitis in the subsequent lactation for 96 last test-day somatic cell score categories. Linear programming was used to optimize the costs of dry cow therapy in 3 simulated large US dairy herds with different bulk tank somatic cell counts (BTSCC). The objective function was aimed at minimization of the total cost of mastitis around the dry period (TCMD), under a varying constraint of the maximum percentage of cows dried off with antibiotics. A sensitivity analysis was performed on milk price, dry-off antibiotic price, and risk ratio of mastitis in the subsequent lactation when no antibiotics and only teat sealant was used at dry-off. For all situations, blanket dry cow therapy was more expensive than SDCT. In a herd with medium BTSCC, the TCMD was $54.7 per primiparous dry cow and $58.5 per multiparous dry cow annually. In the optimal economic situation where SDCT was used, only 30% of primiparous cows received antibiotics, leading to a TCMD of $52.4 per primiparous dry cow, whereas 88% of multiparous cows received antibiotics, at a cost of $58.2 per multiparous dry cow. This corresponded with an overall reduction of 29% in the use of antibiotics around the dry period in a conservative scenario. This study showed that it is economically feasible to reduce antibiotic use associated with dry cow therapy in large US dairy herds. This contributes to the efforts of reducing antibiotic use worldwide.     

Steam reforming of simulated pre-reformed naphtha in a PdAu membrane reactor

Process intensification in a membrane reactor is an efficient and compact way to produce hydrogen. A methane-rich gas mixture that simulated the composition of pre-reformed naphtha (PRN; with a steam-to-carbon ratio of 2.7) was reformed at temperatures of 550 °C–625 °C and pressures up to 40 barg. The reactor contained commercial steam reforming catalyst and a 14.8 cm long, 2.6 μm thick Pd-1.8Au (wt. %) membrane on a porous alumina support. Methane conversions approaching 90% were obtained in the membrane reactor at a gas-hourly space velocity of 676 h^?1, compared to ≤30% conversion at the same conditions in conventional reactor mode (CM) without withdrawing hydrogen through the membrane. The results were compared to steam methane reforming (SMR) in the membrane reactor at similar conditions. The nitrogen leak through the membrane increased slowly during the testing, because of both pinhole formation and some leakage through the end seals.     

The generation of arbitrary-phase polynomials by recurrence formulae

A filter-design oriented theory is presented for polynomials with prescribed phase properties. The phase function is specified by its values and/or higher derivative values at a set of given frequencies. The polynomials are generated by recurrence formulae whose coefficients are calculated by a recursive algorithm. Formulae are presented to calculate the higher derivatives of some composite functions of the phase which are utilized in the process of flat phase approximations.     

Fuel switching in Harare: An almost ideal demand system approach

In urban areas several energy choices are available and the amount of (a given type of) fuel consumed is based on complex household decision processes. This paper analyzes urban fuel (particularly firewood) demand in an energy mix context by means of an Almost Ideal Demand System based on a survey carried out among 500 households in Harare in 2003. Using a multi-stage budgeting approach, the model estimates the share of energy in total household expenditure and the shares of firewood, electricity and kerosene in total energy expenditure. Using the model results simulations show that the main policy handles to reduce the demand for firewood and to mitigate environmental degradation such as deforestation include decreasing prices of alternative fuels, notably kerosene. Moreover, in the long run sound economic policy will positively impact on the energy budget whereas education and the degree of electrification will contribute to a reduction of the use of firewood.     

Decision-induced focusing in social dilemmas: Give-some, keep-some, take-some, and leave-some dilemmas.

Previous research on asymmetric social dilemmas has suggested that public good dilemmas evoke different choice behaviors than do resource dilemmas. The authors propose that these differences reflect a differential focus that is dependent on the way decisions are generally presented in the dilemma types. In agreement with this, the results of 2 experimental studies suggest that, in public good dilemmas, group members are less focused on the consequences of their actions for the final outcome distribution when deciding how many endowments they give to the public good than when deciding how many endowments they keep for themselves. In resource dilemmas, group members are less focused on the final outcome distribution when deciding how many endowments they leave in the collective resource than when deciding how many endowments they take. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultra acidic strong cation exchange enabling the efficient enrichment of basic phosphopeptides

We present a straightforward method to enrich phosphopeptides with multiple basic residues, an under-represented class in common enrichment strategies. Our method is based on a two-dimensional strong cation exchange (SCX) strategy, operating at two different acidic pHs, enabling both separation and enrichment of different classes of phosphopeptides. The principle of enrichment is based on the change of net charge of phosphorylated peptides under strong acidic conditions in the second SCX, whereas the net charge of regular peptides remains unchanged, thus enabling separation based on net charge. Application of our tandem SCX approach to a modest amount of human cells allowed the identification of over 10,000 unique "basic" phosphopeptides of which many represent putative targets of basophilic kinases.     

Rheological behavior and thermomechanical properties of polyethylene—Glycidyl methacrylate vitrimers utilizing disulfide exchange

Four vitrimers were made using polyethylene – glycidyl methacrylate copolymer (PE-GMA) and 3,3′ – dithiodipropionic acid (DTDPA) using a two-step procedure. The amount of DTDPA added was varied, and therefore, the crosslink density was also varied. Rheological experiments were performed. The vitrimers exhibit different rheological behavior depending on the angular frequency applied, which most likely stems from the presence of a crosslinked network. Additionally, there appears to be an on-going reaction occurring during rheological tests, all of which occur above the melting temperature. Thermal and mechanical tests were also conducted. Thermomechanical testing determined that increasing crosslink density resulted in a decrease in the yield strength.     

Heritage attributes of post-war housing in Amsterdam

Modern heritage, particularly post-war social housing estates, is struggling with negative perceptions. Accordingly, this research aims to contribute to a better understanding of the heritage significance of post-war housing estates in general and the Western Garden Cities – a post-war neighborhood in Amsterdam – in particular. A review of the limited body of literature on the heritage significance of modern and post-war housing estates was performed. A significance assessment was conducted on a sample of representative case studies by using expert interviews for data collection. The experts assigned significance levels to attributes based on whether or not they need to be preserved during a sustainable refurbishment. The highest-valued attributes are parcellation, balconies, and semi-public green spaces. The most negative value was assigned to the application of external insulation, replacement of the window frames by PVC-U, and closed character of the façades on the ground floor level. The lack of heritage recognition at the lower scale level may either be due to the important details already being lost or details not yet consistently being recognized as the architecture and buildings are understudied in comparison with the urban qualities of post-war heritage.