Oil Content and Fatty Acid Composition of Seeds of Guizotia Cass (Compositae)

Seeds of Guizotia abyssinica and wild Guizotia were analysed for oil content and fatty acid composition by multisequential and gas chromatographic methods, respectively. The oil content of G abyssinica ranged from 416 to 436 g kg^-1 (weight per kg dry matter of seeds) and that of the wild Guizotia taxa from 214 to 328 g kg^-1. Two unsaturated fatty acids (linoleic (54·3–72·8, weight percent of total oil) and oleic (5·4–26·8% of oil by wt) and two saturated fatty acids (palmitic (7·8–10%) and stearic (5·5–8·1%)) were about 91–97% of the fatty acids present. Palmitoleic, linolenic, arachidic, eicosenoic, behenic, erucic and lignoceric acids constituted about 2–3%. An unidentified fatty acid, probably an epoxy form of C: 20 or C: 22, has been found in all the materials and it was 1·1–6·6%. Total saturated and unsaturated fatty acids were about 74–84% and 15–20%, respectively. Differentiation in fatty acid composition between the taxa is too small to be of taxonomic use. It is inferred that when gene transfer is desired hybridisation between the wild and cultivated taxa may not affect the oil quality of the latter and the oils of the wild taxa are possibly safe for human consumption. © 1997 SCI.     

Composition and properties of bovine milk: A study from dairy farms in northern Sweden; Part II. Effect of monthly variation

This study investigated the influence of monthly variation on the composition and properties of raw farm milk collected as part of a full-scale cheese-making trial in a region in northern Sweden. In our companion paper, the contribution of on-farm factors to the variation in milk quality attributes is described. In total, 42 dairy farms were recruited for the study, and farm milk samples were collected monthly over 1 yr and characterized for quality attributes of importance for cheese making. Principal component analysis suggested that milk samples collected during the outdoor period (June–September) were different from milk samples collected during the indoor period. Despite the interaction with the milking system, the results showed that fat and protein concentrations were lower in milk collected during May through August, and lactose concentration was higher in milk collected during April through July than for the other months. Concentrations of free fatty acids were generally low, with the highest value (0.86 mmol/100 g of fat) observed in February and the lowest (0.70 mmol/100 g of fat) observed in June. Plasmin and plasminogen-derived activities varied with sampling month without a clear seasonal pattern. The pH of farm tank milk ranged from 6.60 to 6.82, with the lowest and highest values in September and February, respectively. The highest somatic cell count was observed in August (201 × 10³ cells/mL) and the lowest in April (143 × 10³ cells/mL). The highest value of gel strength, was recorded in December (88 Pa) and the lowest in July (64 Pa). Rennet coagulation time and gel strength were inversely correlated, with the lowest rennet coagulation time value observed in December. Orthogonal projections to latent structures (OPLS) and discriminant analysis adaptation of OPLS identified casein micelle size and total proteolysis as the milk quality attributes with major responses to sampling month, with smaller casein micelle size and higher total proteolysis associated with the outdoor months. Using discriminant analysis adaptation of OPLS to further investigate causes behind the variation in milk traits revealed that there were factors in addition to feeding on pasture that differed between outdoor and indoor months. Because fresh grass was seldom the primary feed in the region during the outdoor period, grazing was not considered the sole reason for the observed difference between outdoor and indoor periods in raw milk quality attributes.     

Key Properties of Ni?Mn?Ga Based Single Crystals Grown with the SLARE Technique

Magnetic shape memory alloys (MSMAs), exhibit large strains and hence are materials, which could substitute giant magnetostrictive and piezoelectrical materials in actuating devices. The actuation stress needed to induce the strain is much lower than in other actuator materials. Since the strain can be induced without phase transformation by a magnetic field, the development of actuators with high working frequencies is possible. However, for reasonable applications, large strains have to be induced with small magnetic fields. Up to now repeatable magnetically induced strains of 5–10% in magnetic fields of less than 500 mT have been achieved only in single crystals. The production of Ni? Mn? Ga based single crystals is difficult and time consuming. The crystal quality is affected by porosity and impurities. With the Bridgeman based method called Slag Remelting and Encapsulation (SLARE) single crystalline ingots of Ni? Mn? Ga, Ni? Mn? Ga? Fe, and Ni? Mn? Ga? Co of high quality were grown and characterized. The results show that MSMA properties depend on the position within the single crystalline rods due to a composition gradient. The influence of surface treatment demonstrates that the decrease of surface roughness leads to a decrease of twinning stress. MSMAs with twinning stresses above 1 MPa show a magnetic field induced strain (MFIS) when tilting is not restricted by constraints. Softer samples can adapt to constraints much better and show large MFIS. Substituting Ni by Fe and Co, shifted the phase transitions successfully to higher temperatures. Ni? Mn? Ga alloyed with up to 6 at.% Co showed three different martensite structures: a non‐modulated tetragonal structure, a modulated tetragonal structure, showing the same behavior as Ni? Mn? Ga with identical structures and a non‐modulated orthorhombic structure with a stress–strain‐behavior explainable by the double twinning mechanism.     

Vision ergonomics at recycling centres

All municipalities in Sweden offer their inhabitants a service for disposing of large-size and hazardous waste at local recycling centres. Opening hours at these centres include hours of darkness. The aims of this study were to 1) describe user and employee experiences of lighting and signs at Swedish recycling centres, 2) measure and assess the lighting system at the two recently built recycling centres in Linköping and to assess the legibility and visibility of the signs used and 3) propose recommendations regarding lighting and signs for recycling centres. Interviews and questionnaires were used to assess experiences of employees and users, and light measurements were performed. By observing users, activities with different visual demands at different areas within the recycling centres were identified. Based on the literature, standards and stakeholder experiences, recommendations regarding lighting systems and sign design, illuminance, luminance and uniformity are proposed for recycling centres.     

Genetic Encoding of a Bicyclo[6.1.0]nonyne‐Charged Amino Acid Enables Fast Cellular Protein Imaging by Metal‐Free Ligation

Visualizing biomolecules by fluorescent tagging is a powerful method for studying their behaviour and function inside cells. We prepared and genetically encoded an unnatural amino acid (UAA) that features a bicyclononyne moiety. This UAA offered exceptional reactivity in strain‐promoted azide–alkyne cycloadditions. Kinetic measurements revealed that the UAA reacted also remarkably fast in the inverse‐electron‐demand Diels–Alder cycloaddition with tetrazine‐conjugated dyes. Genetic encoding of the new UAA inside mammalian cells and its subsequent selective labeling at low dye concentrations demonstrate the usefulness of the new amino acid for future imaging studies.     

Platinum oxidation and sulphur deactivation in NO x storage catalysts

A review covering some of the key catalytic transformations of the major monoterpene feedstocks. Monoterpenes are key ingredients in the flavor and fragrance industry, with α- and β-pinene (obtained from turpentine) being some of the most important. The review focuses on the hydrocarbons; pinene, limonene, carene, and the interconversion of the monooxygenates; geraniol/nerol, citronellol, citral, and citronellal. The major areas covered are catalytic hydrogenation/hydrogenolysis, dehydrogenation, rearrangement/isomerization/aromatization, reactions with carbon monoxide, epoxidation, and the addition of alcohols and acids.     

Testing for Change in Long‐Memory Stochastic Volatility Time Series

In this article, change‐point problems for long‐memory stochastic volatility (LMSV) models are considered. A general testing problem which includes various alternative hypotheses is discussed. Under the hypothesis of stationarity the limiting behavior of CUSUM‐ and Wilcoxon‐type test statistics is derived. In this context, a limit theorem for the two‐parameter empirical process of LMSV time series is proved. In particular, it is shown that the asymptotic distribution of CUSUM test statistics may not be affected by long memory, unlike Wilcoxon test statistics which are typically influenced by long‐range dependence. To avoid the estimation of nuisance parameters in applications, the usage of self‐normalized test statistics is proposed. The theoretical results are accompanied by an analysis of Standard & Poor's 500 daily closing indices with respect to structural changes and by simulation studies which characterize the finite sample behavior of the considered testing procedures when testing for changes in mean and in variance.     

Single Droplet Mass Transfer Experiments for Acetic Acid Extraction with Triisooctylamine‐Based Solvents

Single droplet mass transfer of acetic acid from aqueous phase into triisooctylamine‐based solvents modified with the Lewis basic modifier tributyl phosphate and the diluent Shellsol T was investigated for applicability in solvent design. Solvent composition of triisooctylamine‐based solvent mixtures has a decisive effect on liquid‐liquid partition of acetic acid. The modifier is needed to correct acid association of the ammonium salt, while the diluent mainly affects the viscosity, the density, and the interfacial tension of the solvent. The results show that single droplet mass transfer is controlled by solvent viscosity.     

The Activity of Nodules of the Supernodulating Mutant Mtsunn Is not Limited by Photosynthesis under Optimal Growth Conditions

Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO₂ assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO₂ assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N₂ fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants.