Milliliter Of Water Research Articles

A TECHNIQUE FOR DETECTING VIRUS-INFECTED MONTMORENCY CHERRY SEEDS

Virus was transmitted mechanically to cucumber seedlings from single, fresh or frozen, sound or aborted, Montmorency cherry seeds. The number of lesions incited varied with the weight of seed per milliliter of water, from seed to seed, and with the interval between thawing and testing. Though virus was detected with inoculum as dilute as 0.014 grams of seed per milliliter of water, dilutions between 0.06 and 0.19 of seed per milliliter (0.5 milliliter of water for each sound seed) are recommended for a high degree of confidence in indexing. Virus was transmitted to cucumber from 77 per cent of the sound frozen seeds from a tree with typical cherry yellows symptoms, 84 per cent of the sound fresh seeds from a tree with recurrent necrotic ringspot symptoms, 11 per cent of the sound and 15 per cent of the seeds with aborted embryos from a healthy tree caged with the latter tree and bees during blossoming, and less than 1 per cent of all of the seeds from six healthy trees surrounded by diseased trees in an orchard.Some of the advantages and limitations of detecting virus in Montmorency cherry seeds by this method are discussed.

Emulsion particle size III. Particle size distributions determined by various growth mechanisms

In a treatment of emulsion polymerization as a stochastic process, the effect of the mechanism of growth of an emulsion polymer particle on the final particle size distribution is examined. If the rate of change of polymer volume is given by: dV/ dt = kr α , where k is a constant and r is the radius of the polymer sphere, then it can be shown that for α equal to 0 the volumes are distributed normally, for α equal to 2 the radii are distributed normally, and for α equal to 3 the logarithms of the radii are distributed normally. The Smith-Ewart theory has α equal to 0 as a basic assumption in the derivation of the dependence of the number of particles per milliliter of water on soap and initiator concentration. Since the acrylic latices and a poly (vinyl acetate) latex that have been examined do not have their volumes distributed normally, caution must be used in extending the Smith-Ewart results.

Laboratory Tests with Sixty-Five Compounds as Repellents against House Flies

The rapid development of resistance to insecticides in house flies (Musca domestica L.) indicates a growing need for other approaches toward their suppression. Food-handling establishments and military installations could well benefit from a repellent. A residual treatment to the approaches to buildings, as well as to areas where refuse is kept would prevent flies from congregating in these locations, and thereby reduce the sources from which they normally migrate into the buildings. Areas around poultry houses and dairy barns could also be sprayed with a repellent until proper disposal of breeding materials could be arranged. In these circumstances a good repellent would not obviate the need for insecticides, but would reduce the frequency of applications and thus retard the development of resistance. At Orlando, Fla., 65 chemicals were tested in the laboratory as vapor or contact repellents against house flies. Some of the compounds were received from commercial laboratories where they had been developed specifically as fly repellents, and others were selected because of their repellency to other species. A semicircle of heavy white cardboard 31/4 inches in radius was sprayed with a 2 percent solution of the repellent in acetone to give a deposit of 200 milligrams per square foot. Twenty-four hours later the card was rolled into the shape of a funnel, stapled, and placed in the top of a standard drinking glass to form an inverted cone trap. The treated side of the card formed the interior of the funnel. Prior to its insertion 10 grams of Edamin (a casein hydrolysate) moistened with 10 milliliters of water was placed in the bottom of the trap as an attractant, and a screen barrier was placed above the solution to prevent contact of flies with the attractant. A duplicate trap containing an untreated funnel was utilized as the standard. The traps were exposed for 30 minutes at opposite ends of a cage, 7 x 10 x 10 inches, containing 100 flies of mixed sexes. The number of females in the untreated trap divided by the number in the repellent trap gave the repellency ratio. Only female flies were counted, as Edamin is much more attractive to females than males. If less than five were captured in the untreated trap, the test was discarded. Duplicate tests were run with each repellent, with 2 sets of funnels and 2 cages of flies. The treated funnels were then stored for aging. Tests were run at 1 and 2 days of aging, after which, if the ratio of repellency remained greater than 2.0, they were tested after 7, 14, 30, 60 and 90 days, until the ratio dropped below 2.0. The results with 28 compounds that were effective for 2 or more days are given in Table 1. The most promising compounds were di-n-octylamine, n-propyl n-octyl sulfoxide, and 3-chloropropyl n-octyl sulfoxide, which were effective more than 90 days. Allyl n-octyl sulfoxide and N-amyl-2,3-norcamphanedicarboximide were effective for 30 days and N(n-pentyl) succinamide, N-n-heptylphthalimide, and N-sec-pentylphthalimide for 14 days.

Lysergic Acid Diethylamide (LSD-25) Antagonists

A. Introduction It has been shown1,2that 2 mg. of crude beef brain extract per milliliter of water blocks the usual effect of 2μg of LSD-25 per milliliter in the outside liquid on the Siamese fighting fish.* The experiments to be reported here are the study of a blocking effect probably produced by another mechanism: the development of tolerance3to LSD-25 in man by the prior administration for a period of days of a compound similar to LSD-25. This compound, 1-methyl-d-lysergic acid diethylamide (MLD-41), produces in man reactions indistinguishable from LSD-25 but has a higher reaction threshold. It will be shown on the basis of our data that MLD-41 affects both the Siamese fighting fish and man in a manner similar to LSD-25. However, there are important differences; in the fish it is about 1/10 as effective as LSD-25, whereas it is approximately 1/3 as effective in man.

A cortisone-resistant abnormality in the diuretic response to ingested water in primary myxedema.

IN NORMAL humans the ingestion of 20 milliliters of water per kilogram of body weight evokes a characteristic water diuresis. After a slight delay, urine flow increases and peak flows are achieved within one hour, at which time a copious dilute urine is excreted. In primary hypoadrenalism the excretion of water after ingesting such a water load is delayed (1, 2). The following report indicates that a similar abnormality in the diuretic response to ingested water is associated with untreated primary idiopathic myxedema. In bypoadrenalism treatment with cortisone reinstates a normal diuretic response to a water load (1, 3). Studies are presented to show that cortisone therapy does not establish a normal diuretic response in untreated primary myxedema, whereas thyroid therapy does in association with the change to the euthyroid state. Studies in postoperative myxedema and in postirradiation myxedema are also reported. MATERIALS AND METHODS Eleven patients (9 female, 2 male) with primary myxedema (8 idiopathi...

Vertical Distribution of Bacteria in Marine Sediments

Off the coast of Southern California bacteria are more abundant in marine sediments than in the overlying water, there being thousands to millions per gram of sediment and only a few hundred or less per milliliter of water. The distribution of bacteria in the sediment is more or less independent of the depth of the overlying water, the temperature of the ocean floor, and the distance from mainland. The bacterial population seems to be influenced more greatly by the organic content of the sediments than by other factors. Vertical sections from cores 40 to 75 cm. in length show that the number of bacteria in the sediments decreases greatly with depth in the upper 5 cm. of the core and more slowly beyond. In the surface slime, aerobes are 5 to 100 times more plentiful than a aerobes, but at depths exceeding 15 centimeters about as many anaerobes as aerobes are present. Both anaerobes and aerobes have been demonstrated at all depths analyzed. The oxidation-reduction potential (intensity factor expressed as Eh) increases with core depth, although the oxygen-absorbing capacity decreases with depth. Both properties are ascribed primarily to bacterial activity. Bacteria recovered from marine sediments exhibit many biochemical processes such as ammonification, proteolysis, nitrate reduction, nitrification, urea fermentation, chitin digestion, methane production, fat hydrolysis, cellulose decomposition, glucose, xylose, and arabinose fermentation and starch hydrolysis.