The Lodicules of Wheat: Pre- and Post-Anthesis

1975 ◽  
Vol 23 (3) ◽  
pp. 451 ◽  
Author(s):  
S Craig ◽  
TP O'Brien
Keyword(s):  
Membranous Wing ◽  
Vascular Region

Development of the lodicules in wheat is described in pre- and post-anthesis flowers. Each lodicule consists of a vascular fleshy body and an avascular membranous wing. At the onset of anthesis, the vascular region swells extensively and subsequently contracts after which the tissues autolyse rap- idly. The membranous wing remains intact. Possible controls and mechanisms of the swelling and destruction of these small organs are discussed.

Electron microprobe analyses of salt distribution in the halophyte Salicornia pacifica var. utahensis

1977 ◽  
Vol 55 (11) ◽  
pp. 1516-1523 ◽  
Author(s):  
D. J. Weber ◽  
H. P. Rasmussen ◽  
W. M. Hess
Keyword(s):  
Electron Microprobe ◽  
High Salt ◽  
Leaf Section ◽  
X Ray ◽  
Salt Ions ◽  
Palisade Cells ◽  
Salt Distribution ◽  
Photosynthetic Cells ◽  
Scanning Electron ◽  
Vascular Region

The halophyte Salicornia pacifica var. utahensis grows in the desert saline playa. The fused leaves form succulent stems and have apparently isolated tracheids in the palisade region as observed by scanning electron microscopy. Frozen shoots were fractured under liquid nitrogen and scanned for Na+, K+, and Cl− with an electron microprobe X-ray analyzer. In young shoots, the palisade cells were low in salts, and the spongy cells had higher concentrations. The salt in the spongy cells provides a high osmotic pressure permitting the plant to absorb more water from the soil. As the shoots matured, the concentration of salts increased in the spongy cells, and the amount of salt in the palisades also increased. The salt ions in the palisades were excluded from the organelles and were mainly present in the vacuoles. Eventually, the leaf section collapsed because of the high salt in the palisade and spongy cells, but the vascular region in the shriveled section continued to function. The sections adjacent to the dead shriveled section remained green and succulent. The salt tolerance appeared to be based on the exclusion of the salt from the photosynthetic cells and on the ability of the succulent stem to function even though sections were dead owing to high salt concentration.

Resting oxygenation of rat and rabbit intestine: arteriolar and capillary contributions

1995 ◽  
Vol 269 (4) ◽  
pp. H1342-H1348 ◽  
Author(s):  
H. G. Bohlen ◽  
J. M. Lash
Keyword(s):  
Small Intestine ◽  
Tissue Oxygenation ◽  
Second Order ◽  
Oxygen Exchange ◽  
Total Reduction ◽  
Arterial Blood ◽  
Rabbit Intestine ◽  
Counter Current ◽  
Vascular Region

Counter-current exchange of oxygen may occur between inflow and outflow microvessels of the small intestine and greatly influence the dominant sites of tissue oxygenation. To determine the location and magnitude of potential exchange, percent saturation of hemoglobin with oxygen (%SHb) was measured in microvessels throughout the intestine of rats and rabbits. Oxygen losses from systemic arterial blood through large and intermediate arterioles (second order, 2A) was 5-7%SHb in both species, and there was no evidence of an increase in percent saturation along intermediate and large venules. A larger loss of oxygen from arterioles and an increase in venous saturation would be evident if significant arteriolar to venular counter-current exchange of oxygen occurred in the submucosa. From 2A to the villus tip, arteriolar saturation decreased approximately 10%SHb in rabbits and approximately 15%SHb in rats; the villus tip percent saturation was 72.9 +/- 3.9%SHb in rabbits and 69.9 +/- 2.9%SHb in rats. An additional decrease of 5%SHb in rabbits and 15%SHb in rats occurred across the villus capillaries and smallest venules. Although the total reduction in percent saturation across the villi was different between the two species, 70-90% of the total arteriovenous oxygen losses occurred in the capillaries and small arterioles of the villi. We found no evidence of counter-current exchange of oxygen in villi or any other vascular region. Rather, as appears to occur in most organs, small arterioles in conjunction with capillaries dominate resting oxygen exchange to tissue.

scholarly journals First Report of Charcoal Rot on Canola Caused by Macrophomina phaseolina in Western Australia

Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 666-666 ◽  
Author(s):  
R. Khangura ◽  
M. Aberra
Keyword(s):  
Western Australia ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
The United States ◽  
Conidial Suspension ◽  
Brassica Napus L ◽  
Longitudinal Splitting ◽  
Eastern Australia ◽  
Lateral Branches ◽  
Vascular Region

In the spring of 2006, canola (Brassica napus L.) plants suffering from wilt were observed in an experimental plot at Merredin, Western Australia. Symptoms on the affected plants were tan-brown, longitudinal streaks along the main stem and on some lateral branches. Lesions on the stem were predominantly unilateral but sometimes covered the entire stem. Some of the lateral branches were completely wilted, and if present, pods were either shriveled or contained small seed. At the base of the stem, the lesions were grayish brown streaks that caused longitudinal splitting of the stem base. Small spherical (55 to 75 μm in diameter) and elongated (75 to 120 μm long) microsclerotia were seen in the pith and vascular region. Roots appeared to be symptomless, but upon removing the epidermis, grayish streaks were also seen on the roots and small sclerotia were observed in the pith and the vascular region of roots. One hundred and four small pieces (1 to 2 cm) of stem and root from 10 symptomatic plants were surface sterilized with 1.25% NaOCl, rinsed twice in sterile distilled water, and plated on potato dextrose agar (PDA) supplemented with 10 ppm of aureomycin. These were incubated under a blacklight at 22°C. Macrophomina phaseolina (Tassi) Goid. was isolated from 80% of the pieces as identified by colony morphology and the size of microsclerotia that ranged between 50 and 190 μm (3). Eight-three isolates were obtained. None of the isolates produced pycnidia on PDA. However, pycnidia (100 to 190 μm) with pycnidiospores (17.5 to 30 × 7.5 to 10 μm) were produced on the affected stems collected from the field. Pathogenicity tests with one of the isolates were conducted on seven 2-week-old canola plants (cv. Stubby). Three uninoculated plants served as the control. Roots of 2-week-old plants were dipped in an aqueous conidial suspension (1 × 104 conidia/ml) of M. phaseolina for an hour while roots of control plants were dipped in sterile water. Inoculated and control plants were repotted in separate pots and transferred to a glasshouse. A week after inoculation, M. phaseolina produced chlorosis of the leaves, and subsequently, complete wilting and death of the inoculated plants. M. phaseolina was successfully reisolated from roots and stems of symptomatic plants. No symptoms developed on the control plants. Pathogenicity was also tested by soaking seeds of cv. Stubby with an aqueous conidial suspension of M. phaseolina for one-half hour and incubating on agar media after drying. Germinating seeds were colonized by the growing mycelium and seedlings were completely killed within a week. Abundant microsclerotia were produced on the dead seedlings. M. phaseolina has been previously reported on canola in the United States (1) and Argentina (2) and more recently has been reported on canola in eastern Australia (4). To our knowledge, this is the first record of occurrence of M. phaseolina on canola in Western Australia and its impact on canola yield needs to be determined. References: (1) R. E. Baird et al. Plant Dis. 78:316, 1994. (2) S. A. Gaetán et al. Plant Dis. 90:524, 2006. (3) P. Holliday and E. Punithalingam. Macrophomina phaseolina. No. 275 in: Descriptions of Plant Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (4) M. Li et al. Aust. Plant Dis. Notes 2:93, 2007.

scholarly journals Is Compensatory Vasoconstrictor Tone in the Hindquarter Vascular Region Induced by Hemorrhage in Conscious Spontaneously

2001 ◽  
Vol 85 (1) ◽  
pp. 109-113
Author(s):  
Yasuhiro Teranishi ◽  
Noriko Iida ◽  
Norio Ishioka ◽  
Hiroshi Sugino ◽  
Taku Amano
Keyword(s):  
Vascular Region

In Vitro Meniscus Integration Potential is Inversely Correlated With Tissue Maturation State

2010 ◽  
Author(s):  
Lara C. Ionescu ◽  
Grant H. Garcia ◽  
Tiffany L. Zachry ◽  
Gregory C. Lee ◽  
Brian J. Sennett ◽  
...  
Keyword(s):  
Older Patients ◽  
Young Patients ◽  
Partial Meniscectomy ◽  
Limited Success ◽  
Meniscus Healing ◽  
Maturation State ◽  
Vascular Region

Meniscal surgeries are amongst the most common procedures performed in orthopedics today. Clinical solutions are few and have limited success, and so partial meniscectomy is a common outcome. While tears are common in older patients, few young patients present with meniscus damage. It is unclear whether juvenile menisci are less susceptible to damage or more given to endogenous repair. Early in development, the menisci are well vascularized throughout their radial expanse, while in adults, vascularity is restricted to the peripheral rim of the tissue, near the synovial margin [1]. Tears in this vascular region often do heal in adults, while those in the avascular inner regions of the tissue do not [2]. This has led to the inference that vascularity is essential for meniscus healing and this manner of thinking has directed numerous repair strategies toward that end [3].

scholarly journals Late increase in luminal diameter of aortocoronary venous bypass grafts associated with an increase in the vascular region under supply

1987 ◽  
Vol 10 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Gunhild Herrmann ◽  
Rüdiger Simon ◽  
Ivo Amende ◽  
Günter Frank ◽  
Hans-Georg Borst ◽  
...  
Keyword(s):  
Bypass Grafts ◽  
Luminal Diameter ◽  
Venous Bypass ◽  
Vascular Region

Ultrabithorax is required for membranous wing identity in the beetle Tribolium castaneum

Nature ◽  
2005 ◽  
Vol 433 (7026) ◽  
pp. 643-647 ◽  
Author(s):  
Yoshinori Tomoyasu ◽  
Scott R. Wheeler ◽  
Robin E. Denell
Keyword(s):  
Tribolium Castaneum ◽  
Membranous Wing
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