INFLUENCE OF THE PATTERN OF DIVIDING SILKWORM COCOONS BY CALIBER AND MASS WHEN SELECTING THEM FOR A TRIBE

All industrial sericulture is based on the feeding of industrial hybrids. The grain (silkworm eggs) for them is prepared at the breeding enterprises. In the production of high-quality hybrid grain, it is very important to select the most homogeneous fraction from the mixture of breeding cocoons and divide this part by sex with high accuracy, so that the females of one breed are crossed with the males of another and vice versa. It is known that the cocoons of the average fraction (caliber and mass) in the breeding party are the most productive. The purpose of this work was to identify the most informative criteria for selecting the qualitative fraction of breeding cocoons; study the main patterns of variation of cocoons by diameter, quantitative ratios divided into fractions by the caliber of cocoons, and the separability of a mixture of cocoons into components by caliber and weight; based on the revealed regularities, develop some new devices designed for sorting cocoons by caliber and dividing them by mass (sex) in the process of preparing hybrid silkworm grain. By the method of mathematical statistics, the regularities of division of the mixture of breeding cocoons by caliber and weight are revealed. The normalized proportion of the average cocoons fraction of 58–70 % and its range of caliber – 2 mm was determined. The possibility of maximum separation of defective components with small and large fractions from the batch in two stages when sorting cocoons by caliber and mass on the developed devices was revealed. According to the results of production feedings, more cocoon yield was obtained (on average, by 10 kg per box (29 g) of grain). Moreover, there were more uniform and varietal cocoons (22 % and 13 % more than in the control variant, respectively). According to the results of unwinding, the total and continuously unwinding length of the cocoon thread in the experimental cocoons is, respectively, 20 and 27 % higher than in the control ones.

Meanings and attitudes regarding education and household spending priorities of the new middle-class families in Brazil

This study investigates how meanings ascribed to education influence lower-income parents on investing (or not) in their children’s education, and how this in turn influences family expenditures and consumption priorities. Based on 62 ethnographic interviews with individuals who had ascended from poverty to the lower fractions of the Brazilian urban middle-class, we examine differences within a relatively homogeneous fraction in terms of social status and income. Three distinct groups emerged: (1) parents who live in the favelas (slums) and see school as an agent to keep children away from deviant behaviours, (2) parents who live in the favelas and invest in education as an enabler of upwards social mobility, and (3) parents from less affluent suburbs who pay for private education to keep their children from interacting with bad influences outside the territory. Even in socially segregated territories, meanings were shaped less by parents’ amount and composition of cultural and economic capitals, and more by their own experiences with the educational system and access to positive role models (or lack thereof). It appears that the meanings attached to education end up defining family expenditures, family budget and important consumption trade-offs. In addition, our findings reveal a subtle, fine-grained mechanism of distinction based on school choice among the class fraction’s members. We draw on Wilson’s social isolation theory to show how parents of similar economic and cultural capital, and who were socialized in a similar cultural milieu, ascribe different meanings to education, and the resulting differences in household consumption patterns. We thus offer insights on the different reproduction mechanisms at play within an economically disadvantaged social fraction that had moved from poverty to the lower urban middle-class in Brazil.

Flavonoids from the bird's foot trefoil seeds (Lotus corniculatus L.)

In the seeds of bird's foot trefoil (<i>Lotus corniculatus</i> L.) the presence of quercetin- and kaempferol heterosides was found. Eight crystalline compounds and one chromatographically homogeneous fraction were obtained from the flavonoid mixture using column chromatography on polyamide and cellulose. By means of TL-chromatography, elemental analysis and UV-spectrometry seven of the isolated compounds were identified to be quercetin, quercetin 3-arabopyranoside (guajaverin), quercetin 3-galactoside, quercetin 3-rhamnoside, kaempferol 3,7-diglucoside, kaempferol 3,7-dirhamnoside kaempferol 3-glucosyl-7-rhamnoside and two remaining ones were only partly characterized a snearer indefinite kaempferol heterosides.

The multiplicity of massive stars

Binaries are excellent astrophysical laboratories that provide us with direct measurements of fundamental stellar parameters. Compared to single isolated stars, multiplicity induces new processes, offering the opportunity to confront our understanding of a broad range of physics under the extreme conditions found in, and close to, astrophysical objects.In this contribution, we will discuss the parameter space occupied by massive binaries, and the observational means to investigate it. We will review the multiplicity fraction of OB stars within each regime, and in different astrophysical environments. In particular we will compare the O star spectroscopic binary fraction in nearby open clusters and we will show that the current data are adequately described by an homogeneous fraction of f ≈ 0.44.We will also summarize our current understanding of the observed parameter distributions of O + OB spectroscopic binaries. We will show that the period distribution is overabundant in short period binaries and that it can be described by a bi-modal Öpik law with a break point around P ≈ 10 d. The distribution of the mass-ratios shows no indication for a twin population of equal mass binaries and seems rather uniform in the range 0.2 ≤ q = M2/M1 ≤ 1.0.

Visualization of the polarity of isolated titin molecules: a single globular head on a long thin rod as the M band anchoring domain?

TII, the extractable form of titin, was purified from myofibrils and separated by high resolution gel permeation chromatography into two fractions (TIIA and TIIB). Novel specimen orientation methods used before metal shadowing and EM result in striking pictures of the two forms. Molecules layered on mica become uniformly oriented when subjected to centrifugation. TIIB comprises a very homogeneous fraction. All molecules reveal a single globular head at one end on a long and very thin rod of uniform diameter. The lengths of the rods have a very narrow distribution (900 +/- 50 nm). TIIA molecules seem lateral oligomers of TIIB, attached to each other via the head regions. While dimers are the predominant species, trimers and some higher oligomers can also be discerned. Mild proteolysis destroys the heads and converts TIIA and TIIB into TIIB-like rods. Similar molecules also result from titin purified from myofibrils by certain established purification schemes. Headless titin molecules show in gel electrophoresis only the TII band, while head bearing molecules give rise to two additional polypeptides at 165 and 190 kD. Immunoelectron microscopy of myofibrils identifies both titin-associated proteins as M band constituents. We speculate that in the polar images of TII the globular head region corresponds to the M band end of the titin molecules. This hypothesis is supported by immunoelectron micrographs of TIIB molecules using titin antibodies of known epitope location in the half sarcomere. This proposal complements our previous immunoelectron microscopic data on myofibrils. They showed that epitopes present only on the nonextractable TI species locate to the Z line and its immediately adjacent region (Fürst, D. O., M. Osborn, R. Nave, and K. Weber. 1988. J. Cell Biol. 106:1563-1572). Thus, the two distinct ends of the titin molecule attach to Z and M band material respectively.

CONSTITUTION OF A WATER SOLUBLE HEMICELLULOSE FROM AMERICAN BEECHWOOD (FAGUS GRANDIFOLIA)

Extraction of beechwood chlorite holocellulose with hot water yielded a hemicellulose in 13.4% yield (based on original extractive-free wood) containing D-xylose 72%, D-galactose 11.0%, and uronic acid 13.2%. Purification of the crude hemicellulose by complexing with Fehling's solution yielded a chemically homogeneous fraction containing D-xylose 83% and 4-O-methyl-D-glucuronic acid 15.5%. Hydrolysis of the fully methylated hemicellulose yielded 2,3,4-tri-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 3-O-methyl-D-xylose, and 3-O-methyl-2-O-(2,3,4-tri-O-methyl-D-glucopyranosyluronic acid)-D-xylose in a molar ratio of 2:35:3:5. On the basis of the methylation data, periodate oxidation, reducing power determinations, and weight average molecular weight values a possible structure for the hemicellulose is proposed.

PURIFICATION AND COMPOSITION OF A POLYURONIDE HEMICELLULOSE ISOLATED FROM WHEAT STRAW

A homogeneous polyuronide hemicellulose has been prepared from a crude hemicellulose isolated from wheat straw holocellulose by hot water. The method of preparation consisted of fractional precipitation of the acetylated hemicellulose from chloroform solution by petroleum ether. Approximately 50% of the recovered fractions consisted of a polysaccharide made up of 28 moles of D-xylose, 5 moles of L-arabinose, and 3 moles of uronic acid and having an [Formula: see text] and a molar ratio, methoxyl: uronic anhydride, of approximately 1.0. Intrinsic viscosity measurements indicated a degree of polymerization of approximately 30. Separation of hexosans present in the original hemicellulose showed that they were not chemically combined with the main pentosan fraction. They were recovered admixed with short chain pentosan material containing a higher proportion of arabinose to xylose than the main homogeneous fraction.

STUDIES ON THE NATURE OF THE VIRUS OF INFLUENZA

The pathogenic agent of influenza A has been sedimented from infected extra-embryonic fluids of the developing chick, embryo by ultracentrifugation. Material so obtained contains two fractions resolvable in the analytical centrifuge cell. The first, a homogeneous fraction, showed a sedimentation constant S20 = 20 to 31 x 10–13. The second showed a sedimentation constant S20 = about 800 ± 100 x 10–13, was much less homogeneous than the first, and was shown to consist principally of aggregated particles of the more disperse fraction. Both fractions contained the virus in essentially equal amounts per unit of protein weight as calculated from nitrogen determinations. Electron micrographs of the isolated virus protein indicated that the predominating unit is roughly spherical in shape and has a modal particle diameter of about 11 mµ, in good agreement with the sedimentation data in indicating a molecular weight of about 650,000. Approximately 300 of the particles having molecular weight of 650,000 were present in the minimal dose producing infection in mice after nasal instillation. The influenza A virus may now be regarded as one of the smallest pathogenic agents thus far isolated. Preliminary analyses indicate that it is also one of the least complex, being composed principally of nucleoprotein.

AN INVESTIGATION OF THE CHLORINATION OF SPRUCE WOOD AND OF THE RESULTING CHLOROLIGNIN

Spruce sawdust was chlorinated under various conditions in an attempt to procure a homogeneous lignin chloride. Success finally attended the use of methyl alcohol as a medium for chlorination. The lignin chloride, which was dissolved by the alcohol during the chlorination and subsequently precipitated by the addition of water, was cream white in color, and analysis showed it to be an alcohol lignin.A homogeneous fraction (No. 2) was obtained from the re-chlorinated product, and it proved to be a chlorinated analogue of Hibbert's monomethylated methyl alcohol lignin, the formulas of the two products being C42H22O6Cl13(OH)2(OCH3)7, and C42H32O6(OH)3(OCH3)7. The molecular weight and the presence of the two hydroxyl groups were confirmed by acetylation, when 2.0 acetyl groups entered the molecule. Eleven of the chlorine atoms in Fraction 2 have evidently replaced ten hydrogen atoms and one hydroxyl group by simple substitution in methyl alcohol lignin, leaving two chlorine atoms which have apparently entered to saturate a double bond. Seven of these chlorine atoms have been shown to be readily removable either by an alkali or by acid reduction. The other six, because of their stable union with the molecule, are surmised to be joined to an aromatic nucleus or at least to some type of ring structure. The product has been shown to react stoichiometrically within limits as narrow as could be expected for such a large molecule.