Gap stability and freeway merging

This paper analyzes freeway data consisting of velocity and gap size measured by sensors of 200ft intervals along the roadway. Distributions of velocity, gap size, and downstream change in gap size (gap stability) are displayed. Differences in actual and expected time of arrival of gaps at an entrance ramp merge point are likewise considered. Finally, several algorithms for scheduling ramp vehicles to intercept freeway gaps, measured at a decision detector upstream from the ramp, are compared.     

Evidence from comparative investigations that impaired platelet activation is not specific for stroke-prone spontaneously hypertensive rats

BACKGROUND AND PURPOSE: Platelet behavior of Sprague Dawley (SD), Wistar (WI), Wistar-Kyoto (WKY), spontaneously hypertensive (SHR), and stroke-prone spontaneously hypertensive rats (SHRSP) was studied in vivo to evaluate the importance of hypertension-related hemostatic disorders. METHODS: The study was based on the model of stimulus-induced pulmonary microembolization of labeled platelets. After injection of 51Cr-labeled homologous platelets into urethane-anesthetized rats, the organ distribution of the platelets was continuously monitored by gamma detectors. Count rates of two detectors--one placed above the animals' thoraxes (C1), the other above their abdomens (C2)-and the ratio of C1:C2 were calculated. The following platelet activators were applied intravenously: adenosine diphosphate (ADP; 50 micrograms/kg), collagen (100 micrograms/kg), and thrombin (50 IU/kg). RESULTS: All three substances caused a reversible pulmonary accumulation of the labeled platelets and hence an increase in C1/C2 (delta C1/C2%). ADP induced a shift of 75% in SD, 52% in WI, 32% in WKY, 30% in SHR, and 31% in SHRSP. Thrombin-mediated shift was 79% in SD, 64% in WI, 58% in WKY, 48% in SHR, and 54% in SHRSP. Collagen induced a shift of 85% in SD, 96% in WI, 84% in WKY, 56% in SHR, and 62% in SHRSP. CONCLUSIONS: Because indistinguishable results were observed in both hypertensive strains, we conclude that impaired platelet aggregation is not specific for SHRSP. Hence, it may not primarily be responsible for the increased occurrence of stroke in these animals.     

The role of juries in patent cases

What should be the role of juries in patent cases? That was the question before the Court of Appeals for the Federal Circuit (CAFC) in two recent cases, Markman vs. Westview Instruments Inc. and Hilton Davis Chemical Co. vs. Warner-Jenkinson Co. As technology has become more complex, questions have been raised as to whether lay juries (or lay judges) are able to understand and make meaningful decisions in patent cases. The general wisdom has been that juries favor patent owners since they tend to have difficulty in seeing the technological importance of small differences, and that they also tend to be more reticent in overturning the original decision of the Patent and Trademark Office to grant a patent. The two cases described illustrate the fine line that sometimes must be drawn between what the judge does and what the jury does in a trial. Being a fine line, it should come as no surprise that neither of these cases was decided unanimously. The majority decisions, however, make it clear that juries will continue to play an important role in patent cases, albeit not as large as they did in the past     

Solar economics—short term costing

Life-cycle cost analysis is traditionally used by advocates of solar energy systems to demonstrate how future increasing annual fuel savings offset the large initial capital expenditure. Payback period and return on investment are cited as proof of the economic desirability of investing in solar. This paper refutes the solar economics based on life-cycle costs as both imaginary and irrelevant. Predicting rates of inflation and fuel escalation, expected life, maintenance costs, and legislation over the next ten to twenty years is pure guesswork. Furthermore, given the high mobility level of the U.S. population, the average consumer is skeptical of long run arguments which will pay returns only to the next owners. In the short-term cost analysis, the house is sold prior to the end of the expected life of the system. The cash flow of the seller and buyer are considered. All the relevant factors, including the federal tex credit and the added value of the house because of the solar system are included.     

Dithioles—constituents for telechelic prepolymers with glycidyl or thiol endgroups

Summary Telechelic prepolymers 2–5 containing thiol-or glycidyl endgroups, respectively are obtained by addition polymerization of dithiols 1a-1f and diglycidylether of bisphenol-A (DGEBA). They have molecular weights of 800 to 2000 g/mol. The structure of the prepolymers is determined by combination of elemental analysis, M_n (VPO)-values, IR-, ¹H-NMR-and ¹³C-NMR spectroscopy. By means of TLC and HPLC these prepolymers were shown to be a mixture of a series of homologous compounds. Furthermore, their oligomer distribution is analysed.     

1H, 13C, 15N nuclear magnetic resonance backbone assignments and secondary structure of human calcineurin B

The calmodulin- and calcium-stimulated protein phosphatase calcineurin, PP2B, consists of two subunits: calcineurin B, which binds Ca2+, and calcineurin A, which contains the catalytic site and a calmodulin binding site. Heteronuclear 3D and 4D NMR experiments were carried out on a recombinant human calcineurin B which is a 170-residue protein of molecular mass 19.3 kDa, uniformly labeled with 15N and 13C. The nondenaturing detergent CHAPS was used to obtain a monomeric form of calcineurin B. Three-dimensional triple resonance experiments yielded complete sequential assignment of the backbone nuclei (1H, 13C, and 15N). This assignment was verified by a 4D HN(COCA)NH experiment carried out with 50% randomly deuteriated and uniformly 15N- and 13C-enriched calcineurin B. The secondary structure of calcineurin B has been determined on the basis of the 13C alpha and 13C beta secondary chemical shifts, J(HNH alpha) couplings, and NOE connectivities obtained from 3D 15N-separated and 4D 13C/15N-separated NOESY spectra. Calcineurin B has eight helices distributed in four EF-hand, helix-loop-helix [Kretsinger, R. H. (1980) CRC Crit. Rev. Biochem. 8, 119-174] calcium binding domains. The secondary structure of calcineurin B is highly homologous to that of calmodulin. In comparison to calmodulin, helices B and C are shorter while helix G is considerably longer. As was observed for calmodulin in solution, calcineurin B does not have a single long central helix; rather, helices D and E are separated by a six-residue sequence in a flexible nonhelical conformation.     

Immobilization of the thrombin inhibitor r-hirudin conserving its biological activity

Surface immobilization of the thrombin inhibitor r-hirudin was carried out on two different polymers. Linkage to poly(urethane-graft-acrylic acid) (PAC/PU) was done via carboxylic acid groups, using a water soluble carbodimide, while the immobilization on a modified poly[(ethene-co-vinyl acetate)-graft-vinyl chloride] (PVC/EVA) was achieved via the alcohol groups of the polymer using HDI as spacer. Direct immobilization of r-hirudin leaded to a remarkable loss of thrombin activity. As proved by means of protein chemical analysis, loss of activity was due to a selective coupling via the N-terminal amino group of r-hirudin, which is essential for its thrombin activity. Based on these results we developed an immobilization method via an -amino group of r-hirudin preserving full biological activity of the r-hirudin coated surface. © 2001 Kluwer Academic Publishers     

The relationship between milk yield and the incidence of some diseases in dairy cows

Logistic regression models were used to examine the relationship between milk yield and incidence of certain disorders. Lactations (n = 2197) of 1074 Holstein-Friesian cows from 10 dairies (25 to 146 cows per dairy) in Lower Saxony were studied. The 305-d yield from the previous and current lactations served as the standards for milk yield. Eight disorder complexes were considered: retained placenta, metritis, ovarian cysts, mastitis, claw diseases, milk fever, ketosis, and displaced abomasum. Each disorder complex was modeled separately. In addition to milk yield, the influences of the lactation number, the calving season and the other disorder complexes were examined with the "herd" factor taken into account. A correlation between retained placenta, mastitis, and milk fever to milk yield during the previous lactation was found to be probable and for ketosis and displaced abomasum such a correlation was found to be possible. A connection to the yield in the current lactation was shown for ovarian cysts, claw diseases, and milk fever. No relationship to milk yield existed for metritis. An influence of the lactation number was also demonstrated in various models. Single models allowed a demonstration of the influences of both milk yield and lactation number. Limitations of the model types are discussed.