Comparison of gravimetry and planimetry in determining dry matter budgets for three species of phytophagous lepidopteran larvae

Gravimetric and a combination areal-gravimetric methods for determining dry matter budgets for leaf eating Lepidoptera were compared. The gravimetric method is based on dry weight/live weight ratios of the leaves fed to the larvae. In the areal-gravimetric method, the quantity of food offered to the larvae is determined from the area of leaf tracings and the dry matter content per unit area of the leaves. The areal-gravimetric method permits the use of larger leaf sprays and an open, gauze enclosed rearing chamber. There were no consistent differences in budget factors (growth, ingestion or egestion), nor were there any differences in the observed variability of the data attributable to the method used. However, the expected variability based on instrument precision for the gravimetric method is less than for the areal-gravimetric method. Experimental factors inherent in the gravimetric method introduce variability to the measurements that are not present in the areal method. Thirty to 60% of the variability in budget factors was attributed to intrinsic properties of the larvae, even though the larvae were taken from the same egg masses.

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Résumé Les budgets en matière sèche consommée par des lépidoptères ont été comparés par les méthodes gravimétrique et planimétrique. La méthode gravimétrique est basée sur le rapport poids sec/poids frais de feuilles consommées par les chenilles. Avec la méthode planimétrique, la quantité d'aliment proposée aux chenilles est déterminée par les tracés de la surface des feuilles et le contenu de matière sèche par unité de surface des feuilles. La méthode de planimétrie permet l'utilisation de plus grands rameaux de feuilles et de cages d'élevage extérieures en gaze. Il n'y avait pas de différence appréciable dans les éléments du budget (croissance, ingestion et déjection), ni aucune différence dans la variabilité observée des données attribuable à la méthode utilisée. Cependant, la variabilité attendue d'après la précision des mesures avec la méthode gravimétrique est inférieure à celle de la méthode planimétrique. est inférieure à celle de la méthode planimétrique. Des éléments expérimentaux, inhérents à la méthode gravimétrique, introduisent une variabilité dans les mesures que l'on n'a pas avec la méthode planimétrique. 30–60% de la variabilité dans la consommation ont été attribués à des paramètres internes à la chenille, même quand elles provenaient toutes de la même ooplaque.

     

Formation of 19-nor-10-keto-25-hydroxyvitamin D3 in cultured mammalian cells

The results of normal mode calculations on the beta 4.4, beta 6.3, beta 5.6, and beta 7.2 structures of gramicidin A are compared with infrared and Raman spectra of crystalline native, crystalline Cs+-bound, and vesicle-bound gramicidin A. The observed frequencies and frequency splittings are in good agreement with an assignment of beta 5.6, beta 7.2, and beta 6.3 structures, respectively, to the gramicidin A molecules in the above three systems.     

Flavan-3-ol Biosynthesis : The Conversion of (+)-Dihydroquercetin and Flavan-3,4-cis-Diol (Leucocyanidin) to (+)-Catechin by Reductases Extracted from Cell Suspension Cultures of Douglas Fir

Extracts of cell suspension cultures from Douglas fir (Pseudotsuga menziesii) needles catalyzed the production of (+)-catechin (2,3-trans flavan-3-o1) from the 2,3-trans-flavan,3,4-cis-diol (leucocyanidin) in a NADPH-dependent reductase reaction at pH 7.4. Catechin was also produced, along with the 3,4-cis-diol, in a double step reduction from (+)-dihydroquercetin. It was necessary to eliminate any thiol such as 2-mercaptoethanol or dithiothreitol from the extract or assay mixture because these thiols apparently formed thioethers with the 3,4-diols.     

Nodular pulmonary amyloidosis.

An elderly man had a 10-year history of multiple pulmonary nodules that he had refused to have investigated. He died of a ruptured abdominal aortic aneurysm. At autopsy the nodules were shown to consist of amyloid. There was no evidence of systemic amyloidosis.     

Changes in phospholipids of Saccharomyces cerevisiae associated with inositol-less death.

Two inositol-requiring strains of Saccharomyces cerevisiae were examined for changes in levels of phospholipids occurring after inositol deprivation. Lack of inositol results in loss of cell viability (inositol-less death) and in very large increases in two phospholipid precursors, phosphatidic acid and CDP-diacylglycerol; the accumulation of other glycerophospholipids continues for a considerable time at normal rates. Phosphatidylinositol accumulation does not occur in the absence of inositol; however, the further metabolism of this lipid continues, with 80 to 90% of this lipid disappearing. This disappearance is matched by increases in the phosphoinositol containing sphingolipids and extracellular glycerophosphoinositol. These changes are not observed when growth is blocked by cycloheximide or by omission of lysine from a lysine auxotroph, most lipids continuing to accumulate long after growth stops. There appears to be no close coordination in the synthesis of the major yeast phospholipids or between protein synthesis and phospholipid synthesis. However, despite very large changes in the composition of yeast phospholipids that can be achieved by altering culture conditions, it appears that the average charge per phospholipid molecule remains fairly constant.     

Effect of interferons on protein synthesis in human lymphocytes: enhanced synthesis of eight specific peptides in T cells and activation-dependent inhibition of overall protein synthesis

Lymphoblastoid and fibroblast IFN inhibited PHA stimulation of overall protein synthesis in human lymphocytes by ca. 30%. Inhibition occurred within the first 6 hr of PHA treatment and was not progressive. DNA synthesis at 48 hr was inhibited to the same extent. Overall protein synthesis in resting lymphocytes was not detectably inhibited by IFN concentrations up to 1000 U/ml. Thus, inhibition of protein synthesis and subsequent reduction of cell proliferation by IFN require certain early events in mitogen activation. Resting lymphocytes were not unresponsive to IFN treatment, however. Two-dimensional electrophoretic analysis of newly synthesized proteins after IFN treatment showed enhanced synthesis of a specific set of eight peptides (I-peptides), which were shown to be synthesized in T lymphocytes. This enhancement was produced by both IFN-alpha and IFN-beta after 4 to 6 hr of exposure and was identical for all lymphocyte donors studied. After growth stimulation, IFN treatment produced no enhancements of additional peptides, although the original eight I-peptides were enhanced as usual. It is concluded that the biochemical activities of the I-peptides, which remain to be determined, cannot inhibit protein synthesis in resting lymphocytes, but may do so after mitogen activation, when the major physiologic restriction of lymphocyte protein synthesis is released. Alternatively, the I-peptides may be unrelated to regulation of protein synthesis but may be involved in viral protection or enhancement of NK activity.     

Major gene analysis of quantitative variation in blood clotting factor X levels.

Blood clotting factor ten (X) levels measured in 149 people in six pedigrees were found to fit a mixture of normal distributions. No environmental effect could be identified to account for the wide separation in the means of these distributions. Pedigree analysis reveals that the data are compatible with an autosomal, one locus, two allele genetic model affecting factor X activity. Goodness of fit tests suggest that the allele for low levels of factor X is dominant, though on the basis of likelihood tests, mean heterozygote levels are different from mean homozygote levels. A similar bimodal distribution for factor X levels observed previously in a separate sample of 207 young men, indicated that the proposed dominant allele has an estimated population gene frequency of .53. The earlier estimate is remarkably similar to that obtained with the currently ascertained pedigrees. The postulated major gene accounts for more than half of the variation in factor X levels.     

Secondary structure of mouse and rabbit α- and β-globin mRNAs: Differential accessibility of α and β initiator AUG codons towards nucleases

The nucleotide sequence from the 5′ terminus inward of one third of mouse α- and β^maj-globin messenger RNAs has been established. In addition, using 5′ ³²P end-labeled mRNAs as substrates and S1 and T1 nucleases as probes for single-stranded regions, the secondary structures of mouse and rabbit α- and β-globin mRNAs have been analyzed. Our results indicate that the AUG initiator codon in both mouse and rabbit β-globin mRNA is quite susceptible to cleavage with S1 and T1 nucleases, suggesting that it resides in a single-stranded exposed region. In contrast, the initiator AUG in the α-globin mRNA of both species is inaccessible to cleavage, indicating that it is either buried by tertiary structure or is base-paired. Since the rate of initiation of protein synthesis with β-globin mRNA in rabbit reticulocyte is 30–40% faster than for α-globin mRNA, these results imply a possible correlation between the differential rates of initiation with these two mRNAs and the accessibility of the respective AUG initiator codons.     

Isolated Aortocoronary Bypass Operations in Patients Over 70 Years of Age: A Comparison With Results in Patients 50 to 59 Years Old

The early and late morbidity, mortality and beneficial effects of isolated aortocoronary bypass operations in a group of 35 patients 70 years old or older were compared with those factors in patients 50 to 59 years old. The patients in both groups were matched according to the year in which the operation was done and the number of vessels bypassed. Left ventricular function, estimated by the angiographically calculated ejection fraction, was not statistically different in the two groups. Cardiac index, while adequate in both groups, was significantly lower in the older age group. Comparisons were made of “early” events, such as perioperative myocardial infarction, perioperative death and length of post-operative hospital stay; and of “late” events, including myocardial infarction, angina pectoris, congestive heart failure and death, which occurred after patients were discharged from the hospital. The mean length of follow-up of patients was similar in both groups.In comparing early events in the two groups, there was no statistically significant difference in the incidence of perioperative myocardial infarction, perioperative mortality or mean length of postoperative hospital stays. With regard to late events, there was no statistically significant difference in the incidences of myocardial infarction, angina pectoris or mortality.