A New Method for Making an Artificial Air Space on Top of Fertilized Avian Eggs

M. CALLEBAUT

doi:10.3382/ps.0600723

The Long Spacings of Rubber and Cellulose

Rubber Chemistry and Technology ◽

10.5254/1.3544892 ◽

1931 ◽

Vol 4 (2) ◽

pp. 213-218

Author(s):

George L. Clark ◽

Kenneth E. Corrigan

Keyword(s):

Direct Measurement ◽

Unit Cell ◽

New Method ◽

X Ray ◽

Vulcanized Rubber ◽

Air Space

Abstract 1. A new method for the examination of highly polymerized compounds is proposed. This consists in the direct measurement from diffraction interferences of colloidal micelle dimensions. 2. The construction of an instrument consisting of an x-ray tube with magnesium target and vacuum camera without intervening window or air space is described. 3. The major spacing of unstretched vulcanized rubber is found to be 99.3 A˚. U. 4. The number of isoprene molecules per unit cell is estimated to be of the order of eight thousand. 5. Three measurements of the long spacings of cellulose are recorded.

Download Full-text

Techniques and Problems in the Propagation of Sapogenin-bearing Yams from Stem Cuttings

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v53i3.11158 ◽

1969 ◽

Vol 53 (3) ◽

pp. 191-198

Author(s):

Franklin W. Martin ◽

Herminio Delpín

Keyword(s):

Root Growth ◽

Steroid Hormones ◽

Shoot Growth ◽

New Method ◽

Stem Cuttings ◽

Ethylene Chlorohydrin ◽

Air Space

Sapogenin-bearing yams, the sources of steroid hormones, were propagated by leaf-stem cuttings, which is a new method of propagation for this type of yam. Experiments were conducted to determine the effect of such factors as the season of the year, position of the leaf on the stem, and treatments with hormones and fungicides on the propagation of two species of medicinal yams (D. composita and D. floribunda) from leaf-stem cuttings. It was found that an important factor in the propagation from leaf-stem is the use of young, vigorous, succulent leaves. Leaves produced during the spring have these characteristics. Cuttings can be made from all available leaves. It was also found that hormones stimulate root growth and that, if good sanitation is practiced, fungicides are not necessary. Treatments with ethylene chlorohydrin in sealed containers, at the rate of 0.25 ml. per liter of air space, stimulate shoot growth. The two species tested are completely different in behavior with respect to their ability to respond to the treatments applied. The cuttings should be treated by an intermittent mist-spray schedule which keeps them damp. Differences in rootability resulting from the position of the leaf on the stem were significant in both species. The treatments given to cuttings prior to rooting influenced their survival and rooting.

Download Full-text

Selective Sampling and Orientation of Non-Homogeneous Tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100238 ◽

1968 ◽

Vol 26 ◽

pp. 98-99

Author(s):

C. C. Clawson ◽

L. W. Anderson ◽

R. A. Good

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Light Microscopy ◽

Random Sampling ◽

New Method ◽

Microscope Examination ◽

Small Areas ◽

Selective Sampling ◽

Large Numbers ◽

Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Download Full-text

Quantitative Microscopic Comparison of the Organization of the Lung in Transgenic Mice Expressing Transforming Growth Factor-α (TGF-α)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162533 ◽

1996 ◽

Vol 54 ◽

pp. 14-15

Author(s):

C. G. Plopper ◽

C. Helton ◽

A. J. Weir ◽

J. A. Whitsett ◽

T. R. Korfhagen

Keyword(s):

Growth Factor ◽

Pulmonary Fibrosis ◽

Transgenic Mice ◽

Blood Vessels ◽

Lung Parenchyma ◽

Lung Maturation ◽

Alveolar Air ◽

Parenchymal Tissue ◽

Air Space ◽

Conducting Airways

A wide variety of growth factors are thought to be involved in the regulation of pre- and postnatal lung maturation, including factors which bind to the epidermal growth factor receptor. Marked pulmonary fibrosis and enlarged alveolar air spaces have been observed in lungs of transgenic mice expressing human TGF-α under control of the 3.7 KB human SP-C promoter. To test whether TGF-α alters lung morphogenesis and cellular differentiation, we examined morphometrically the lungs of adult (6-10 months) mice derived from line 28, which expresses the highest level of human TGF-α transcripts among transgenic lines. Total volume of lungs (LV) fixed by airway infusion at standard pressure was similar in transgenics and aged-matched non-transgenic mice (Fig. 1). Intrapulmonary bronchi and bronchioles made up a smaller percentage of LV in transgenics than in non-transgenics (Fig. 2). Pulmonary arteries and pulmonary veins were a smaller percentage of LV in transgenic mice than in non-transgenics (Fig. 3). Lung parenchyma (lung tissue free of large vessels and conducting airways) occupied a larger percentage of LV in transgenics than in non-transgenics (Fig. 4). The number of generations of branching in conducting airways was significantly reduced in transgenics as compared to non-transgenic mice. Alveolar air space size, as measured by mean linear intercept, was almost twice as large in transgenic mice as in non-transgenics, especially when different zones within the lung were compared (Fig. 5). Alveolar air space occupied a larger percentage of the lung parenchyma in transgenic mice than in non-transgenic mice (Fig. 6). Collagen abundance was estimated in histological sections as picro-Sirius red positive material by previously-published methods. In intrapulmonary conducting airways, collagen was 4.8% of the wall in transgenics and 4.5% of the wall in non-transgenic mice. Since airways represented a smaller percentage of the lung in transgenics, the volume of interstitial collagen associated with airway wall was significantly less. In intrapulmonary blood vessels, collagen was 8.9% of the wall in transgenics and 0.7% of the wall in non-transgenics. Since blood vessels were a smaller percentage of the lungs in transgenics, the volume of collagen associated with the walls of blood vessels was five times greater. In the lung parenchyma, collagen was 51.5% of the tissue volume in transgenics and 21.2% in non-transgenics. Since parenchyma was a larger percentage of lung volume in transgenics, but the parenchymal tissue was a smaller percent of the volume, the volume of collagen associated with parenchymal tissue was only slightly greater. We conclude that overexpression of TGF-α during lung maturation alters many aspects of lung development, including branching morphogenesis of the airways and vessels and alveolarization in the parenchyma. Further, the increases in visible collagen previously associated with pulmonary fibrosis due to the overexpression of TGF-α are a result of actual increases in amounts of collagen and in a redistribution of collagen within compartments which results from morphogenetic changes. These morphogenetic changes vary by lung compartment. Supported by HL20748, ES06700 and the Cystic Fibrosis Foundation.

Download Full-text