Milliliter Of Water Research Articles

Distribution and Overcrowding Effects in Mosquito Larvae (Diptera: Culicidae) Inhabiting Taro Axils in the Ryukyus, Japan

Distribution and overcrowding effects were examined for the immature population of Aedes flavopictus miyarai and Malaya genurostris inhabiting taro axils in Ishigaki Island, the Ryukyus. The distribution pattern of Ae. f. miyarai larvae and pupae and Ml. genurostris larvae in taro axils was contagious and fitted the negative binomial series. Mosquito (both species combined) density in mosquito-positive axils was very high, the average and the maximum being 2.75 and 43 larvae plus pupae per millilitre of water, respectively. In 1st-and 2nd-instar larvae of Ae. f. miyarai, no correlation was recognized between body size and larval density. In older larvae and pupae of Ae. f. miyarai, body size was inversely correlated with density. In Ml. genurostris, the tendency was not so clear. Field specimens of Ae. f. miyarai (except lst-instar larvae) were smaller than laboratory ones reared with ample supply of food under temperature and photoperiod conditions similar to those in the field.

A radiochemical assay for argininosuccinate synthetase with [U- 14C]aspartate

A simple and sensitive radiochemical procedure to assay argininosuccinate synthetase activity in crude tissue homogenates and lysates of cultured cells is described. The new method depends on the location of 14C, uniformly, in the four carbons of aspartate. On incubation in the presence of excess of l-[U- 14C]aspartate, l-citrulline, ATP, and an ATP-generating system, argininosuccinase and arginase, the [ 14C]fumarate formed is measured as the sum of malate and fumarate. After acidification the latter two acids are separated from [ 14C]aspartate on a small Dowex-50 column by elution with a few milliliters of water; the unutilized amino acid substrates remain on the column. With a specific radioactivity of 9 × 10 4 cpm, 1 to 2 nmol of product can be accurately measured under kinetically optimum conditions.

Effects of food deprivation on water intake induced by intermittent delivery of salted liquid food

The water intake of rats maintained through food deprivation at 70, 80, 90, and 100% of free-feeding body weights was examined under conditions where a small amount of sweetened condensed milk containing 8% sodium chloride was presented at one-minute intervals. For each of two subjects, number of licks and milliliters of water consumed varied inversely with body weight. This finding agrees with earlier reports concerning the effects of food deprivation on adjunctive behaviors induced by intermittent delivery of dry food.

Optic Nerve Retrieval After Enucleation

SUMMARY Occasionally a surgeon does not obtain an adequate length of optic nerve during enucleation surgery for a suspected intraocular malignancy. Retrieval of an additional nerve segment can be accomplished rapidly utilizing a glass test tube containing a few milliliters of water as an orbital endoscope. Under direct visualization, the remainder of the optic nerve can be located, grasped with a curved clamp, and sectioned with scissors.

A Simple Device to Immobilize Mice for Infection with Schistosoma mansoni Cercariae

changes in light and temperature from the dark 27 to 28 C snail room to the bright 31 to 33 C collecting chamber stimulate developed cercariae to emerge abundantly. (5) If desired, the cercarial harvest can be increased even more by a double shedding procedure in which emerged cercariae are poured off the snails at 0900 hr, the beakers refilled with 22 to 23 C water, and cercariae collected again at 1000 hr. (6) Individual snails 5 to 7 mm in diameter are exposed to miracidia to insure equal exposure. Using a fine micropipette, 8 to 10 miracidia are transferred in a small drop of water into the center of a flat-bottomed glass vial (15 x 60 mm) which has been siliconed to prevent spread of the drop. Each tube is checked to insure the correct number of miracidia. Five milliliters of water and one snail are added and the vials are kept in the snail warm room overnight. Snails are then maintained as described above. (7) Insofar as possible, the growth of rotifers which colonize the snail shells, immobilizing the cercariae, decreasing the numbers which emerge and reducing their infectivity (Stirewalt and Lewis, Int. J. Parasitol., in press) is controlled by swabbing the shells with 10% ethanol. Especial care is taken to clean the shell crevices. The alcohol-treated snails are rinsed in dechlorinated tap water before they are put in clean aquaria. Using these procedures, we have for several years been collecting an average of 2,800 (range from day to day of 2,000 to 4,000, occasionally 5,000) cercariae per snail per day. Under the usual laboratory conditions of uncontrolled light and temperature and cercarial harvesting every other day, our average was 1,000 (range of 600 to 1,800) cercariae per snail per day. These averages were calculated from the total cercarial harvest from snails in all stages of patency of infection. These conditons have not been thoroughly tested on any other intraspecific associations of Schistosoma mansoni and Biomphalaria glabrata. Some modifications may be necessary for optimal cercarial production from other parasite-snail combinations. This work was supported by an Office of Naval Research Contract No. N00014-76-C0146. e is, Int. J. Parasitol., in press) is

Incidence of R factors in coliform, fecal coliform, and Salmonella populations of the Red River in Canada.

Coliforms, fecal coliforms, and Salmonella were isolated from the Red River, Manitoba, Canada, and identified. These organisms were then examined for resistance to 12 antibiotics. Some fecal coliforms were resistant to all 12 antibiotics, and 18% of the Salmonella isolates were resistant to one or more antibiotics. A total of 52.9% of the fecal coliforms resistant to three or more antibiotics were able to transfer single or multiple resistance (R) determinants to the Salmonella recipient, and 40.7% could transfer R determinants to the Escherichia coli recipient. Of the resistant Salmonella, 57% transferred one or two determinants to the Salmonella recipient, and 39% transferred one or two determinants to the E. coli recipient. It was calculated that populations of fecal coliforms containing R factors were as high as 1,400 per 100 ml and that an accidental intake of a few milliliters of water could lead to transient or permanent colonization of the digestive tract. Consideration of data on bacteria with R factors should be made in future water quality deliberations and in discharge regulations.

Radioimmunoassay による血中 dextranase の測定について第1報

Dextranase labelled with 125Iodine was applied by means of a radioimmunoassay to detect any change in the permeability of the oral mucosa under test.For the purpose of this experiment, two groups were selected:Group one contained three individuals with clinically healthy gingivae.Group two contained six individuals with periodontally diseased gingivae.The treatment was undertaken using different concentrations of the dextranase solution. The maximum effective concentration was twenty five nano-grames of dextranase to one millilitre of water (25ng/ml) (B/Bo=90 percent)There was no remakable change in the condition of either the control or the diseased cases. Nor was there any significant improvement in the cases with periodontally diseased gingivae. Moreover, the dextranase was not found to cause any senitive reaction in the human body.

Studies on the Analysis of Phthalate Esters in Foods

A new procedure for the determination of phthalate esters in edible oil was investigated with the aim of seperating them from oil and organochlorine insecticides.The method consists mainly of 4 steps: n-Hexane-acetonitrile partition, subsequent addition of a few millilitres of water into acetonitrile layer and removal of n-hexane released, followed by the extraction with a small amount of conc. sulfulic acid and finally use of minicolumn chromatography on florisil (1g). It was found that more than 99.5% of oil was removed by this procedure and organochlorine insecticides as well.Throughout the present method, the recoveries of phthalate esters fortified in the levels of 0.3-11ppm were 90% (DBP), 82% (DHP), 81% (DEHP), and 75% (BPBG).

Determination of cyanide ion in cyano-complexes

A method is described for the determination of the CN– ion in a variety of cyano-complexes. The method is based upon mixing and grinding the sample with flowers of sulphur and potassium chloride in the ratio of 1:2:2; the addition of potassium carbonate is also essential with cyano-acid complexes. After mixing, a micro-amount is fused in a test-tube at about 300 °C for 2 minutes and the tube is then broken in a few millilitres of water. In this way the CN– ion is converted quantitatively into CNS–, which is determined colorimetrically. The average recovery is 98·54 per cent.

The release of oxygen from polystyrene Petri dishes.

There have been many reports regarding radiobiologically significant amounts of oxygen dissolved in plastic dishes (Chapman et al., 1968 and 1970; Boag, 1969). Recently Davies and Baker (1970) showed this indirectly by comparing the equilibration of several millilitres of water in a plastic and a glass Petri dish. The method of equilibration was by rapid flushing of nitrogen over the dish. Their results suggested that it would take several days (at a rate of approximately 12 hours per ten-fold decrease in oxygen tension) to reach an oxygen concentration of less than 0·03 micromolar in the liquid contained in a plastic dish. Also, Chapman et al., (1970) showed that for a 0·1 cm thick slab of polystyrene the effusion rate of oxygen declined at a rate of about eight hours per ten-fold change. The equations describing oxygen effusion from plastic depend upon exp (-π2Dt/4a2) for (Dt/a)>0·2, where D is the diffusion coefficient, t is time, and 2a is the thickness of the plastic (Chapman et al., 1970). However, the thickness of 60 mm tissue culture polystyrene Petri dishes (Falcon) normally used in North America is only 0·065 cm. Therefore, in actual practice with this thickness the oxygen concentration should fall by a factor of 10 in 3·4 hours.

Changes in the electroencephalogram of the chicken produced by stimulation of the crop.

Synopsis Injection of 2 ml water at 2 °C or 2 ml 1 N NaCl at 18 °C directly into the duodenum produces EEG arousal. Two millilitres of water at 18 °C have no effect.

Changes in the electroencephalogram of the chicken produced by stimulation of the duodenum.

Synopsis Injection of 2 ml water at 2 °C or 2 ml 1 N NaCl at 18 °C directly into the duodenum produces EEG arousal. Two millilitres of water at 18 °C have no effect.

Gas chromatography of γ-BHC in milk by steam distillation method

A simple and rapid procedure for gas chromatography of γ-BHC in milk has been presented. Six milliliters of water were added to 1 ml of milk. The first 25 ml of its steam-distillate was shaken with 10 ml of n-hexane and then an aliquot of the extract was applied to gas chromatography. Conditions of gas chromatographic separation are shown in Fig. 1.

Eutrophication Speeded by Man

Lakes always die. Their life span is determined by the physical, chemical and biological conditions to which they are subject. Lakes begin by being oligotrophicnearly sterile-with clear, clean water. Gradually silt and nutrients are added. Some of the nutrients come from minerals leached from the sides and bottom of the lake or from organic materials. Silt, other minerals and organic materials come from streams supplying the lake. Eventually the nutrients stimulate increased plant growth, and the character of animal life in the lake changes. In time the mass of new mineral and biological material fills the lake and it becomes a marsh. From marshes, lakes finally become solid land. The whole process is called eutrophication. Without man's interference, the time span for eutrophication is measured in tens of thousands of years or longer, depending on individual conditions. Man, by adding his nutritive wastes to lakes, has compressed the process, sometimes into the space of a few years. The classic case is Lake where the process of eutrophication has indeed been immensely accelerated. But many other lakes, in North America and all over the world, have also become eutrophic because of man's activities. Fortunately, the process is very often reversible; several area report progress. Eutrophication is a complex process, varying from lake to lake in its character, rates and causes. But in most eutrophic bodies of water in the United States, the limiting nutrients are compounds of phosphorus or nitrogen, with phosphorus apparently the more important contributor in most cases. A limiting nutrient is one that acts as an accelerator or decelerator of eutrophication as its amounts are increased or decreased. All other essential nutrients exist in sufficient quantities for more or less unlimited growth, and the limiting nutrient becomes the controlling factor. Although phosphorus is usually the limiting nutrient in North American lakes, sometimes nitrates play the key role, as is apparently the case in Lake Tahoe, on the California-Nevada border. Sometimes nitrogen and phosphorus act together as limiting nutrients. Nitrogen and phosphorus are the main elements causing eutrophication in Lake Erie, says Dr. Frank K. Wilkes of the Federal Water Quality Administration research division in Washington, D.C. He adds, however, that organic materials are also sometimes suspected of being the key nutrients. Scientists use certain standard parameters to gauge the degree of eutrophication in a body of water. Because of the key role nitrogen and phosphorus play, the amounts of these two substances provide a frequently used guideline. Because stimulation of plant growth is a prime effect of eutrophication, the amount of chlorophyll in a lake is another commonly used parameter, as is a simple measurement of the weight of plant growth per acre. The number of plant cells per milliliter of water is .M

Lick volume determined by food schedules in rats

The number of licks and fluid consumed were recorded separately for 10 rats during a 7-day adjustment period followed by a 33-day period during which the animals were fed for only 2 h each day. Significant differences in the number of licks per milliliter of water consumed between food and no-food periods appeared after the first experimental week. There was a significant decrease in lick rate from the first to the second hour of each feeding period and also from the feeding to the nonfeeding period. Use of a lick count to determine volumes of fluids ingested on different feeding schedules could be misleading.

The Bacterial Flora of Peripheral Vascular Ulcers

A complete bacteriological study was made of skin ulcerations associated with peripheral vascular disease in 40 consecutive untreated patients, and a method of colony counting was devised. In all but five ulcers, thee was bacterial growth of at least 2,000 colonies per milliliter of water, and the total count was not well correlated with the presence or absence of clinical signs of inflammation. Staphylococcus aureus and the Enterobacteriaceae were most common in the ulcers appearing clinically inflamed whereas the indolentappearing ulcers tended to have less virulent organisms. Further work is necessary to determine whether the surface infection found in clinically inflamed ulcers is significant and warrants antibacterial therapy.

Spectrophotometric determination of phenylephrine hydrochloride in pharmaceutical preparations

Phenylephrine HCl (I) reacts with 4-aminoantipyrine and K3Fe(CN)6 in an alkaline medium buffered at pH 9 to give orange coloration. The chromogen produced extracted into chloroform gives an absorption maximum at 460 mμ.A new spectrophotometric method based on this color reaction has been established for the determination of (I) in pharmaceutical preparations.Influences of 45 compounds on the determination were examined, whereby those by sulpyrine, aminopyrine, isopropylantipyrine, acetaminophen, ethoxybenzamide, salicylate, theophylline, quinine HCl, ascorbic acid, taurine, etc. are eliminated by the extraction with chloroform in acidic medium.The procedure recommended is as follows. A sample {containing 50 mg of (I)} is taken in a separatory funnel. Ten milliliters of water and 10 ml of 0.1 N HCl are added, and interfering substances is extracted 3 times with 30 ml portions of chloroform. The aqueous solution is transfered into a 50 ml volometric flask and is diluted exactly to 50 ml with water. A 2 ml aliquot is taken into another 50 ml volumetric flask and made up to the mark with water. Two milliliters of this solution is transfered to a 25 ml glass-stoppered test tube, and 10 ml of 0.2 M borate buffer, 2 ml of 1% 4-aminoantipyrine solution, and 2 ml of 2% K3Fe (CN) 6 solution are added. After allowing to stand for 5 min., it is shaken with 10 ml of chloroform for 1 min. The separated chloroform layer is dried by shaking with 2 g of Na2SO4, and the absorbance is measured at 460 mμ (ET) against chloroform. At the same time, the absorbance of the standard solution (Es) is determined, and the amount of (I) is calculated by ET/ES.

Aluminum-26 and Beryllium-10 in Greenland Ice

Activities of beryllium-10 and aluminum-26 dissolved in 200-year-old Greenland ice were found to be 18.4 (+ 8.4, - 4.8) x 10(-6) and 3.2 +/- 0.9 x 10(-7) disintegration per minute per liter, respectively. From these values and the precipitation rate (30 milliliters of water per square centimeter per year), the production rates of these isotopes are calculated to be 3.6 (+ 1.6, - 0.9) x 10(-2) and 1.7 +/- 0.5 x 10(-4) atom per second * square centimeter. These rates agree with the rates calculated for the production of these isotopes by cosmic rays in the atmosphere. Probably all the Al(26) in the ice is accounted for by such atmospheric production; however, an upper limit for the influx of cosmic dust bearing aluminum-26 is calculated at 3.2 x 10(5) tons per year for Earth. Only upper limits could be found for Al(26) and Be(10) in the undissolved particulate matter in the ice; their addition to the activities in the dissolved material leaves our conclusions unchanged.

Enteropathogens in Water With Low Esch. Coli Titer

The discovery of S. montevideo in the water supply of a collective settlement in Galilee (Israel) prompted the investigators to examine for enteropathogens all those waters that could be considered suspect either because of their appearance (turbidity, particularly after inundations) or because unexplained enteritis cases occurred amongst the users of a given water. A total of 400 water samples were examined for the number of bacteria (colony count) and for the number of fecal Escherichia coli (complete test) according to standard methods. The samples were also tested for enteropathogens by centrifuging twenty milliliters of water at 2,000 rpm for 15 minutes. The deposit was cultured in a Mueller‐Kauffmann enrichment medium from which BGB plates were inoculated and suspicious colonies were identified by the usual biochemic and serologic methods. The isolated strains were submitted for confirming tests to the Israel Salmonella Center in the Central Laboratories at Jerusalem.

Studies of the Effect of Light on Protective Coatings Using Aluminum Foil as a Support: Determination of Ratio of Chain Breaking to Cross-Linking

A convenient demonstration of this procedure can be arranged by using some of the new feltor nylon-tipped writing tools. Some of these have permanent color inks; some, water-soluble inks (e.g., Esterbrook Felt-Riter pens). If two such pens, one with permanent ink and one with water-soluble ink, are both used to mark a small piece of paper or cloth, the water mark can be removed completely without touching the permanent color mark. The paper or cloth is hung in a sealed glass jar with a few milliliters of water in the bottom. In a few weeks at room temperature, or less time (a few days) at elevated temperatures (say 150?F on a hot plate), the water-soluble ink will be completely removed and the permanent color markings will be unchanged. s or cloth may be su ported on another sheet of paper. oce s may be a c lerated by heating the container l although one must first be certain that n compoi soluble at r om temperature becomes soluble at an e te perature. Before risking any museum object to this treatment one must be very sure of the relative solubilities of all of the various components of the object. The usual method of removing soluble matter on the surface of objects by employing cotton swabs wetted with the solvent is a safer procedure in the sense that exposure to the solvent is very short and trials can be made at the edges. Even if this traditional procedure is to be used, the solubility test described above should be employed because it requires less material and because it gives the operator more confidence that he has found the proper solvent.