Role of agonist and antagonist muscle strength in performance of rapid movements

Six subjects performed rapid self-terminated elbow movements under different mechanical conditions prior to, and 5 weeks after an elbow extensor strengthening programme. Despite the large difference in the strengths of elbow flexors and extensors, the pretest did not demonstrate significant differences between the movement time of flexion and extension movements performed under the same mechanical conditions. The results obtained in the posttest demonstrated a decrease in movement time (i.e. an increase in movement speed) in both elbow flexion and extension movements under some mechanical conditions. In addition, flexion movements demonstrated a relative increase in the acceleration time (acceleration time as a proportion of the movement time). It was concluded that the strength of both the agonist and antagonist muscles was important for the performance of rapid movements. Stronger agonists could increase the acceleration of the limb being moved, while stronger antagonists could facilitate the arrest of the limb movement in a shorter time, providing a longer time for acceleration.     

Male and female contributions to heterosis in lifetime performance of mice

Summary Six straightbred lines of mice, some of their F₁ crosses and a synthetic line were used to evaluate male and female contributions to heterosis in lifetime performance measured on females. Females from each straightbred line or F₁ crosses were pair-mated randomly at day 42 with either a male of the corresponding genetic group or from a synthetic line, and pairs were maintained for 155 days (lifetime). Each mother was allowed to rear all young born alive until day 18 when the young were discarded. Data were analyzed using a model in which the group mean of lifetime performance was expressed as the sum of (additive direct) genetic and environmental effects for each of the male and female genetic groups used for mating. Comparison of group means for lifetime performance revealed that estimates of F₁ heterosis due to male and female averaged 10 and 9% for number of parturitions during lifetime, 7 and 28% for total number of young born alive, 6 and 31% for total body weight of young born alive, 8 and 33% for total number of young raised to day 18, 9 and 43% for total body weight of young raised to weaning, and 8 and 8% for days from first mating to last parturition. The male's contribution to heterosis in lifetime performance was smaller than female's contribution for productive traits (total number of young born alive and at day 18, and total body weight of young born alive and at day 18), and was nearly equal in reproductive traits (number of parturitions during lifetime and days from first mating to last parturition).Animal Research Centre Contribution No. 1098     

Family resemblance for neuromuscular performance in a Kansas Mennonite community

Familial phenotypic resemblance for six quantitative neuromuscular performance traits is analyzed by path analysis using data from the Mennonite community of Goessel, Kansas. Of the six traits only one, dominant hand strength, shows no evidence of parent-offspring transmission (t2 = 0.001) and only one, trunk flexibility, shows evidence of a high degree of transmissibility (t2 = 0.662). The four remaining traits display low to moderate levels of transmissibility (t2 = 0.073 to t2 = 0.245). A substantial residual sibling resemblance due to shared environmental effects is seen for all six traits. It is suggested that the high heritabilities found for many of these traits by other methods result from the inability of these methods to account for the shared nongenetic effects.     

A chemiluminescent probe specific for singlet oxygen

We have synthesized a methoxyvinylpyrene (MVP) in order to model the mechanism for the observed microsomal chemiluminescence of benzo[a]pyrene 7,8-dihydrodiol, the proximate carcinogenic metabolite of benzo[a]pyrene. This MVP analog has been found to be a highly efficient and specific chemiluminescent probe for picomole quantities of singlet oxygen and singlet oxygen equivalents, and it produces significant chemiluminescence when reacted with cytochrome P-450 enzymes.     

Purification to apparent homogeneity of a thymocyte specific growth factor from calf thymus

A thymic peptide previously found to recruit thymocytes from G1 into S phase has been purified from a crude thymic extract by subsequent steps of gel exclusion chromatography and reverse phase high performance liquid chromatography (HPLC). The purified material, which appeared homogeneous on thin-layer chromatography and HPLC, stimulated the DNA synthesis of cultured guinea pig thymocytes in a nanomolar concentration range. The amino acid composition revealed a high content of acidic amino acids and no apparent homology to previously defined growth factors and thymus differentiation hormones.     

Selective activation of cyclic AMP dependent protein kinase by calcitonin in a calcitonin secreting lung cancer cell line

When the F1-ATPase from the thermophilic bacterium, PS3, was inactivated by 90% with 7-chloro-4-nitro[14C]benzofurazan ([14C]Nbf-Cl) at pH 7.3 and then gel-filtered, 1.25 mols of [14C]Nbf-O-Tyr and less than 0.1 mol of Nbf-N-Lys were formed per mol of enzyme. After adjusting the pH of the gel-filtered, modified enzyme to 9.0 and incubating it for 14 hrs. at 23 degrees C to promote O----N migration, 0.68 mol of Nbf-N-Lys were formed per mol of enzyme while about 16% of the original activity reappeared. Isolation of the subunits after the O----N migration showed that 90% of the incorporated 14C was present in the beta subunit, which contained 0.21 mols of [14C]Nbf-N-Lys per mol. A tryptic peptide which contained the majority of the 14C incorporated into the beta subunit was isolated and subjected to automatic amino acid sequence analysis contained 38 residues. The amino acid sequence immediately around the lysine residue labeled with [14C]Nbf-, K*, was found to be: ...I-G-L-F-G-G-A-G-V-G-K*-T-V-L-I-G... .     

Chemie und Systematik in der FlechtengattungRhizocarpon: Hochdruckflüssigkeitschromatographie (HPLC) der Flechten-Sekundärstoffe derRhizocarpon superficiale-Gruppe

The secondary lichen products of 31 specimens of theRhizocarpon superficiale group are examined by high performance liquid chromatography (HPLC). At 260 nm 13 different compounds have been detected. 6 of them are well-known lichen acids which occur in nearly all the species; but proportions are different and constant for each species. An analytical key is added.

Beitrag I einer Publikationsreihe.     

Analysis of picogram quantities of indole-3-acetic acid by high performance liquid chromatography-fluorescence procedures

The use of spectrofluorimeter coupled to a reverse phase high performance liquid chromatography column permits selective detection of indole-3-acetic acid at the low picogram level. The value of the technique is demonstrated by the analysis of endogenous IAA in elongating shoots, xylem sap and callus of Douglas-fir. The data are also used to illustrate a procedure whereby the accuracy of chromatographic analyses can be verified within definable probability limits.Abbreviations GC-MS combined gas chromatography-mass spectrometry - HPLC high performance liquid chromatography - IAA indole-3-acetic acid - SEC steric exclusion chromatography - SICM selected ion current monitoring Technical Paper No. 5379 from the Oregon State University Agricultural Experiment Station     

Comparison of the nucleotide sequence of cloned DNA coding for an apolipoprotein (apoVLDL-II) from avian blood and the amino acid sequence of an egg-yolk protein (apovitellenin I): equivalence of the two sequences

We have compared the amino acid sequences of two low-molecular-weight avian apoproteins: apoVLDL-II from very low-density lipoproteins of hen plasma and apovitellenin I from hen egg yolk. The sequence of White Leghorn apoVLDL-II was derived from the nucleotide sequence of cloned apoVLDL-II DNA (Chan et al., 1980). The sequenator was used to determine the amino acid sequence of apovitellinin I from two breeds of hen (White Leghorn and Australorp). The sequences from the two breeds were not only identical, but they also completely matched the predicted sequence derived from the apoVLDL-II DNA sequence. The identity reported here establishes that this protein is transported intact from the blood to the egg yolk.     

SEAWEED ANATOMY AND PHOTOSYNTHETIC PERFORMANCE: THE ECOLOGICAL SIGNIFICANCE OF LIGHT GUIGES,HETEROGENEOUS ABSORPTION AND MULTIPLE SCATTER12

Light absorption by two green seaweeds with similar photophysiology but different anatomies are compared: i) Ulva lactuca var. rigida (C. Ag.) Le Jolis, an optically translucent species of two cell layers both bearing chloroplasts; and, ii) Codium fragile subsp. tomentosoides (van Goor) Silva, an optically opaque species with a colorlelss medulla surrounded by a cortex of choloroplast-bearing utriclels. Thallus absorptance (fraction of incident light absorbed) was measured for various pigment contents. Absorptance by U. lactuca was dependent on pigment concentration in an exponential manner and never exceeded 0.6, whereas absorptance by C. fragile was independent of pigment concentration and always approached a balue of 1.0. Water in the medullary tissue of C. fragile is often of the utricles. The utricles appear to be “integrating spheres” enhancing the capture of incident light, aided by the wave-guide function of the thin peripheral layer of cytoplasm and a reflector function at their base. Photosynthitic performance for U. lactuca saturates at high light intensities and attenuates rapidly with decreasing intensities. In contrast, photosynthetic performance for C. fragile saturates at low light intensities and attenuates slowly with diminishing radiation. Extrapolated diel variation in photosynthesis shows that U. lactuca's anatomy is adaptive for high light intensity environments, whereas C. fragile's anatomy is adaptive for low light intensity environments. Both seaweeds fit into the ecological category of “fugitive” species, and compete in the Long Island Sound (Atlantic Ocean) rocky intertidal for free-space. Predictions are presented for relative species abundances along a monotonic gradient of light intensity.