Multilane vehicular traffic and adaptive human behavior

The parameters in a statistical theory of multiple-lane traffic have been determined from two independent sets of data. The numerical values of the parameters calculated by four different methods of estimation are in essential agreement with one another. The data suggest the important role of adaptive human behavior in determining the characteristics of congested flow.     

Dietary regulation of galactose-metabolizing enzymes: adaptive changes in rat jejunum

The effects of dietary galactose, sucrose, fructose, glucose, casein, and fasting upon the activity of four galactose-metabolizing enzymes (galactokinase, galactose-1-phosphate uridyltransferase, uridine diphosphate galactose 4-epimerase, and galactose dehydrogenase) were studied in the jejunum of rats. Galactose produced the greatest increase in enzyme activity, fructose and sucrose produced effects intermediate between galactose and glucose, and casein produced a greater activity increase than fasting, but less than the sugars.     

The detection of large HNO3-containing particles in the winter Arctic stratosphere

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.     

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.     

Assessment of bovine mammary chemokine gene expression in response to lipopolysaccharide, lipotechoic acid + peptidoglycan, and CpG oligodeoxynucleotide 2135

During intramammary infections pathogen associated molecular patterns (PAMPs) induce an inflammatory response, recognized clinically as mastitis. Recognition of PAMPs by mammary cells leads to the production of the pro-inflammatory cytokines, TNF-α and IL-1β. These cytokines augment the secretion of various chemokines that are responsible for directing the host cellular immune response, and consequently the outcome of infection. Previous research has shown that gram-negative and gram-positive bacteria elicit different types of innate immune responses. The purpose of this study, therefore, was to characterize the expression of various chemokine genes in bovine mammary gland explants in response to lipopolysaccharide (LPS), peptidoglycan (PTG) combined with lipotechoic acid (LTA), and CpG oligodeoxynucleotide (CpG-ODN) 2135 representing gram-negative bacteria, gram-positive bacteria, and bacterial DNA, respectively, to determine if these PAMPs induce different chemokine gene expression patterns. Explants from 3 Holstein cows were cultured with 10 μg/mL of LPS, LTA + PTG, or CpG-ODN 2135 for 6 and 24 h. Total RNA was extracted and the expression of CXCL8, MCP-1, MCP-2, MCP-3, MIP1-α, and RANTES genes was measured by real-time polymerase chain reaction (RT-PCR). Lipopolysaccharide significantly induced MCP-1, MCP-2, and MCP-3 expression, and slightly increased CXCL8 gene expression. The combined PAMPs, LTA + PTG, on the other hand, significantly induced MCP-1 gene expression, and slightly increased MCP-3 expression. No significant expression differences for any of the chemokine genes were observed in explants stimulated with CpG-ODN 2135. These results demonstrate that PAMPs associated with different mastitis-causing pathogens induce chemokine-specific gene expression patterns that may contribute to different innate immune responses to bacteria.     

Occurrence of two forms of Y chromosome in rainbow trout (Oncorhynchus mykiss) males from Rutki strain

Morphologically differentiated sex chromosomes are found in only few salmonid species. Some populations of rainbow trout, Oncorhynchus mykiss, exhibit chromosomal polymorphism related to sex. We found sex-related chromosomal polymorphism in fish from the synthetic Rutki strain, Poland, in approximately 85% (n = 22) of examined males (XY-like) whereas the remaining males (n = 4) possessed chromosomes similar to these observed in females (XX-like). To investigate whether males possessing XX-like chromosomes were genotypic males or genotypic females with altered phenotypic sex, androgenetic progeny of four males (representing both XY-like and XX-like forms, n = 2 + 2) was examined. Androgenetic progeny (F₁) of all four fathers consisted of both phenotypic females and males. F₁ male progeny of two fathers showed XX-like chromosomes whereas F₁ male progeny of the other two fathers possessed YY-like (supermale) chromosomes. F₁ were reared further until they were sexually mature. Two males from each of four F₁ families were used to produce F₂ androgenetic and control F₂ generation. All F₂ individuals, androgenetics and control, were phenotypic males at sexual maturation. The results indicate that males possessing XX-like chromosomes are genetic males and they are not sex-reversed females. Thus, the Y chromosome can exist in different morphological forms in farmed rainbow trout. The Y^S chromosome (shorter form, unlike the X chromosome) has a shorter or absent p-arm and lacks the pericentromeric cluster of AT-rich chromatin and the 5S rDNA sequences that are found in the Y^L chromosome (longer form, like the X chromosome).