Changes in the Localization of {beta}-Glycerophosphatase Activity During the Infection of Phaseolus vulgaris by Colletotrichum lindemuthianum

Histochemical methods showed that epidermal cells of Phaseolusvulgaris (cv. Kievit) contained lysosomelike particles richin ß-glyceTophosphatase. The behaviour of these organellesduring infection by different physiological races of Colletotrichumlindemuthianum has been examined. Host cell death during theresistant (hypersensitive) response of the bean to infectionby incompatible races ß and occurred during the secondand third days after inoculation. Cell death appeared to becoincident with the release of ß-glycerophosphataseinto the cytoplasm and a reduction in size and number of stainingparticles. Invading incompatible hyphae were restricted to singlenecrotic cells. In contrast, for 4 days, infection by the compatiblerace caused little alteration in particulate staining whileconsiderable fungal colonization took place. Subsequent observationsrevealed a decrease in the number of enzyme-rich particles whichwas not associated with the appearance of diffuse staining evenafter cell necrosis. It is suggested that the release of ß-glycerophosphataseand possibly other hydrolases from the lysosome-like particlesof the host caused hypersensitive cell death, and that necrosiswas not controlled by the plant in this way during the susceptibleresponse.     

Fine Structure and Cytochemistry of the Abscission Zone Cells of Phaseolus Leaves: II. Localization of Peroxidase and Acid Phosphatase in the Separation Zone Cells

The sub-cellular localization of acid phosphatase and peroxidaseactivities has been studied by cytochemical procedures in cellsat the surface of the separation layer during the abscissionof leaves of Phaseolus vulgaris. Intense staining for both enzymeswas found in the cell walls, Golgi bodies and endoplasmic reticulum.The wall staining for acid phosphatase was chiefly associatedwith the middle lamellar region while staining for peroxidasewas found throughout the wall. These observations are discussedin relation to the possible involvement of these enzymes inthe changes occurring in the wall during abscission and to therole of the Golgi bodies in the separation process.     

Fruit abscission and ethylene production of four blackberry cultivars (Rubus spp.)

In all cultivars the force required to harvest fruit declined during ripening. The fruit retention strength (FRS) of ripe fruit varied between cultivars with ‘Ashton Cross’ and ‘Chehalem’ being easier to remove than ‘Bedford Giant’ or ‘Oregon Thornless’. The cultivars ‘Ashton Cross’ and ‘Oregon Thornless’ showed no increase in ethylene production during fruit ripening whereas ‘Bedford Giant’ and ‘Chehalem’ had increased rates of ethylene production (EPR) in the ripe fruit. Exogenous ethylene accelerated abscission, ethylene production and pigment changes in ‘Ashton Cross’ fruit at all stages of development. 1-amino-cyclopropane-1-carboxylic acid (ACC) supplied to fruit at all stages of development was converted to ethylene at levels in excess of those found naturally. The differences between cultivars are discussed with reference to the role of ethylene in both machine harvesting and post-harvest storage of blackberry fruit.     

Mumps meningoencephalitis; a clinical review of 119 cases with one death

Mumps is one of the most common viruses to affect the central nervous system and should be given primary consideration in the differential diagnosis of aseptic meningitis. Many cases of numps infection do not involve the salivary glands. The course of numps meningoencephalitis is usually benign, with fever and signs of meningeal irritation lasting less than five days. The findings in the cerebrospinal fluid are usually distinctive, with leukocyte content greater than 200 per milliliter, of which 80 per cent or more are lymphocytes. Sequelae, even of a minor nature, are rare. Death is extremely rare in recorded literature. A fatal case of numps meningoencephalitis is described herein.     

Fine Structure and Cytochemistry of the Abscission Zone Cells of Phaseolus Leaves: I. Ultrastructural Changes occurring during Abscission

The fine structure of the separation zone cells from the basalabscission zone of bean leaves has been described. Examinationof these cells revealed that fracture occurred primarily asa result of the dissolution of the middle lamellar region ofthe walls, leaving intact cells on the two newly exposed fracturesurfaces. The cytoplasm and organelles within these cells appearedquite normal and showed no signs of autolysis or senescence.A comparison of the organelle numbers in these cells with cellsfrom a similar region of a control plant revealed large increasesin the number of Golgi bodies and the amount of rough endoplasmicreticulum. The significance of this finding is discussed inrelation to the secretion of cell wall hydrolysing enzymes whichare known to be produced in these cells.     

The Role of Ethylene in the Shedding of Red Raspberry Fruit

The production of ethylene by red raspberry (Rubus idaeus L.cv. Glen Clova) fruit increased climacterically during development.The concentration of ethylene within green fruit was low butincreased substantially as fruit abscission and ripening commenced.The receptacle contained higher concentrations than the drupeletsat all stages measured. In the mature ripening fruit the ethyleneconcentrations were found to be physiologically significant,and would accelerate the abscission of large green non-abscisingfruit if supplied as a fumigant. The addition of ethylene toripe fruit did not accelerate abscission, probably because saturatinglevels occurred naturally within these fruit. Reduction of ethylenesynthesis rates using the inhibitor of ethylene production aminoethoxyvinylglycine(AVG) reduced the rate of abscission zone weakening which occursin detached large green fruit. The rate of ethylene productionwas found to be dependent on the supply of the precursor l-aminocyclopropane-l-carboxylicacid (ACC). This only accumulated to any extent in those ripefruit with high rates of ethylene production. Rubus idaeus, raspberry, abscission, fruit ripening, ethylene, aminocyclopropane-l-carboxylic acid     

Evaluation of Techniques for Categorizing Group Membership of White-Tailed Deer

Abstract: We studied sexual segregation, particularly patterns of group membership for white-tailed deer (Odocoileus virginianus), in Lincoln County, Minnesota, USA, to evaluate current techniques used to categorize animals when studying sexual segregation. We categorized group membership according to Hirth (1977) and grouped individuals using our solitary categorization method. Our solitary method was most sensitive to changes in behavior and physiology exhibited by reproductively active females and their association with other deer during sexual segregation.