A two-fluid approach to town traffic

A two-fluid model of town traffic has been developed by extending ideas formulated in an earlier kinetic theory of multilane traffic. The-two fluids are taken to consist of moving cars and cars stopped as a result of traffic conditions. The average speed of the moving vehicles is assumed to be proportional to the fraction of the vehicles that are moving raised to a power that reflects the "goodness" of the traffic. It is then found that the trip time per unit distance is essentially linearly related to the stop time per unit distance, in general accord with data obtained in many cities. Relations are developed on this basis for flow, among other variables, versus average speed. These relations contain a new parameter that is identified with the quality of the traffic network system.     

Changes in nutritional composition of Russet Burbank potatoes by different processing methods

Russet Burbank potatoes from the same storage lot, were processed by commercial technology and prepared for consumption as done institutionally and in the home. Products were chosen to include most of the processing or preparation steps that will influence nutrient losses, namely, boiling, baking, frying, and drying. Products were evaluated on an as-served-basis for potato solids, starch, total and reducing sugar, total and protein nitrogen, free amino acid, vitamin, and mineral contents. Comparisons of the quantity of these nutritional components in different prepared potato products were made and discussed.     

Secoisolariciresinol and matairesinol of sea buckthorn (Hippophaë rhamnoides L.) berries of different subspecies and harvesting times

Sea buckthorn (Hippopha? rhamnoides) seeds, berries, and berry fractions are often used as sources of bioactive ingredients for health products. The aim of the present study was to analyze lignans in these fractions of sea buckthorn. Secoisolariciresinol and matairesinol in seeds, fruit pulp/peel, and whole berries of sea buckthorn of three subspecies were analyzed by isotope dilution gas chromatography-mass spectrometry. The total content of the two lignans secoisolariciresinol and matairesinol varied widely from 8 to 139 microg/100 g in fresh berries and from 51 to 319 microg/100 g in dry berries. The content of secoisolariciresinol varied in the range of 34-313 microg/100 g of dry mass in the fruit pulp/peel and 93-355 microg/100 g in dry seeds. The content of matairesinol fell within the range of 3-25 microg/100 g in dry pulp/peel and 1-13 microg/kg in dry seeds. Wild H. rhamnoides ssp. sinensis contained a significantly higher total level of secoisolariciresinol and matairesinol in dry seeds, dry berries, and fresh berries compared with wild ssp. rhamnoides (253 vs 135 microg/100 g, P < 0.01, in seeds; 224 vs 153 microg/100 g, P < 0.05, in dry berries; 71 vs 29 g/100 g, P < 0.01, in fresh berries) and the cultivar of ssp. mongolica (253 vs 112 microg/100 g in seeds, 71 vs 9 microg/100 g in fresh berries). Harvesting dates had a significant influence on the content of the two lignans in seeds, fruit pulp/peel, and whole berries. This is the first report of lignans in sea buckthorn.     

The efficacy of the bone markers osteocalcin and the carboxyterminal cross-linked telopeptide of type-I collagen in evaluating osteogenesis in a canine crural lengthening model

The aim of the present study was to determine the efficacy of the bone markers osteocalcin (OC) and carboxyterminal cross-linked telopeptide of type-I collagen (ICTP) in evaluating new bone formation in the dog, using commercially available immunoassay kits. Dogs were randomly divided into three groups and a circular external skeletal fixation system (CESF) was mounted on the tibia. In the first group a distraction osteogenesis procedure of the crus was performed. The second group received an osteotomy without crural lengthening, whereas the third group served as a sham-operated control. Bone formation was assessed using densitometric image analysis of crural radiographs. Despite significant differences in the amount of newly formed bone, this finding was not reflected in the plasma levels of OC and ICTP. In conclusion, OC and ICTP were not efficacious as markers of bone formation and resorption during osteogenesis in this canine model.