Conformation of liquid short chain polyethers from flow birefringence

The stress-optical coefficient (?) has been determined from flow birefringence measurements for the short chain polymers poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) over a range of temperatures and molecular weights (DP from 1 to 200 for PEG, 1 to 40 for PPG). By using samples blended from monodisperse material of known M_n, it is shown that it is the z-average molecular weight that characterizes the stress-optical coefficient. Hence in making comparisons between various samples of the same material due to different authors, it is necessary to have a knowledge of the z-average molecular weight of the sample. A critical comparison is made of the number of monomer units per statistical segment (the parameter describing chain conformation) as derived from the theories of Lodge, Gotlib and Svetlov, and Noda and Hearst.     

Feather protein as a support for immobilizing enzymes

Feather meal protein was prepared in granular form and used as a support for lactase using glutaraldehyde as the crosslinking agent. The support gave a high retention of activity and in column operation it yielded apparent half-lives from 50 to 100 days. Because of its gel-like consistency (water content of about 90%), there is some diffusional restricting of activity as indicated by the kinetic data of soluble and immoblized enzymes.     

Frequency of the carrier state for X-linked chronic granulomatous disease among females with lupus erythematosus

Carriers for chronic granulomatous disease (CGD) and patients with lupus erythematosus (LE) share several characteristics: They are mostly females, they reduce nitroblue tetrazolium (NBT) poorly in their neutrophils, and, in some cases, they have similar skin lesions. We thus investigated 19 female LE patients for the presence of laboratory findings characteristic of the carrier state for CGD. None of these patients turned out to have the combined abnormality of neutrophil bactericidal activity and neutrophil NBT-reduction that is diagnostic of CGD carrier state in the X-linked form. An increased frequency of CGD carriers among female LE patients thus appear to be unlikely. Why some CGD carriers develop skin lesions typical of LE remains unexplained.     

Expected locations of digits and letters on ten-button keysets.

In an attempt to find out where people expect to find letters and numbers on each of six configurations of ten keys, 300 Ss were asked to write on keyset diagrams either letters or numbers in arrangements they felt were most natural. Results showed that people expect (1) to find numbers arranged in left-to-right order in horizontal rows starting with the top, (2) to find letters, two or three on a key, in the same arrangement, and (3) to find letters arranged in horizontal rows when numbers already on the keyset are so arranged, but when the numbers are arranged otherwise (e.g., in vertical columns) the Ss divided about equally in arranging the numbers in horizontal rows and in vertical columns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduction of central nervous system reperfusion injury in rabbits using doxycycline treatment

BACKGROUND AND PURPOSE: Activated leukocytes appear to potentiate central nervous system reperfusion injury, and agents that block leukocyte adhesion have shown neuroprotective efficacy in experimental models. Doxycycline, a tetracycline antibiotic, inhibits leukocyte function in vitro, presumably through divalent cation binding. We used a model of focal central nervous system reperfusion injury to determine the efficacy of doxycycline treatment in preserving neurological function. METHODS: Rabbits randomly received 10 mg/kg i.v. doxycycline 30 minutes before ischemia (pretreatment group) or 45 minutes after ischemia (posttreatment group) or received phosphate-buffered saline vehicle (control group) followed by 10 mg/kg q 8 hours times two. The average length of reversible spinal cord ischemia required to produce paraplegia (P50) at 18 hours was calculated for each group. RESULTS: For the control group (n = 13), the P50 was 22.8 +/- 2.2 minutes; for the pretreatment group (n = 14), 35.5 +/- 2.4 minutes (P < .01; t = 3.8); and for the posttreatment group (n = 13), 31.4 +/- 4.2 minutes (not significant; t = 1.6). Doxycycline also attenuated postischemic decreases in vivo leukocyte counts and inhibited in vitro leukocyte adhesion. Therapeutic doxycycline levels at 24 hours were confirmed in the plasma and spinal cord. CONCLUSIONS: This significant protective effect suggests that doxycycline, a safe and readily available agent, may play a role in reducing clinical central nervous system reperfusion injury.     

Decomposing road freight energy use in the United Kingdom

Applying the techniques of decomposition analysis we estimate the relative contribution of ten variables (termed ‘key ratios’) plus GDP to the change in UK road freight energy use over the period 1989–2004 inclusive. The results are best interpreted as an estimate of the percentage growth in energy consumption that would have resulted from the change in the relevant factor (e.g. length of haul) had the other factors remained unchanged. The results demonstrate that the main factor contributing to the decoupling of UK road freight energy consumption from GDP was the decline in the value of domestically manufactured goods relative to GDP. Over the period 1989–2004 this largely offset the effect of increases in GDP on road freight energy consumption. While the decline in domestic manufacturing was to some extent displaced by increases in imports, the net effect of these supply factors, together with shifts in the commodity mix, has been to reduce UK road freight energy consumption by 30.1%. The net effect on global carbon dioxide (CO₂) emissions is likely to be somewhat less beneficial, since many freight movements associated with the manufacture of imported goods have simply been displaced to other countries.     

Effect of corn particle size on site and extent of starch digestion in lactating dairy cows

Two experiments were conducted to determine the effects of corn particle size (CPS) on site and extent of starch digestion in lactating dairy cows. Animals were fitted with ruminal, duodenal, and ileal cannulas. Dry corn grain accounted for 36% of dry matter intake. In experiment 1, 6 cows were used in a duplicate 3 x 3 Latin square design. Semiflint corn was used. Corn processing methods were grinding, medium rolling, and coarse rolling. The mean particle size of the processed corn was 730, 1807, and 3668 microm, respectively. Rumen digestibility of starch linearly decreased from 59% with ground corn to 36% with coarsely rolled corn. Similarly, small intestine digestibility linearly decreased with increased CPS, and consequently, the amount of starch digested in the small intestine was not affected by corn processing. In experiment 2, 4 cows were used in a 2 x 2 crossover design. Dent corn was used. Corn processing methods were grinding and coarse rolling. The mean particle size of the processed corn was 568 and 3458 microm, respectively. Rumen digestibility of starch decreased from 70% with ground corn to 54% with coarsely rolled corn. Small intestine digestibility of starch was not significantly affected by CPS, and the amount of starch digested in the small intestine tended to be greater for rolled than for ground corn. In both experiments, starch total tract digestibility decreased with increased CPS. In conclusion, CPS is an efficient tool to manipulate rumen degradability of cornstarch. In midlactation cows, the decrease in the amount of starch digested in the rumen between grinding and coarse rolling is partly compensated for by an increase in the amount of starch digested in the small intestine with dent genotype, but with semiflint genotype postruminal digestion is not increased and rumen escape starch is not utilized by the animal.