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PubMed2006

Accurate diagnosis of Giardia spp and proper fecal examination procedures.

A series of investigations evaluated the ability of different testing methods - a swing-head centrifugation technique using two flotation solutions (1.18-specific gravity zinc sulfate and 1.27-specific gravity Sheather's sugar solution), a passive commercial flotation technique, and the SNAP Giardia Test Kit from IDEXX Laboratories - to identify Giardia-positive dogs and recover the eggs of other intestinal parasites. It was determined that the SNAP Giardia test can improve a practice's ability to identify Giardia-infected dogs. Because of its higher specific gravity, the sugar solution was better for recovering heavy parasite eggs, such as Taenia spp, and thus is the flotation solution of choice when conducting routine centrifugation fecal examinations.

Animals↗
PubMed2002

Evaluation of cerebral gas retention and oedema formation in decompressed rats by using a simple gravimetric method.

OBJECTIVE: The objective of the study is twofold: first, to develop a specific gravity method for distinguishing between bubbles and oedema following decompression, and, second, to evaluate the extent to which the change in specific gravity is due to retained gas in cerebral tissue. METHODS: A brombenzene/kerosene gradient column was used to measure changes in brain specific gravity at 100 and 300 kPa, respectively. This study was performed on 23 rats. Non-exposed rats constituted the control group A (n=6). The exposed animals were divided into two groups according to the number of bubbles they developed upon decompression; group B (bubble grade 0-2, n=9) and group C (bubble grade 3-5, n=8). RESULTS: Cerebral gas retention was determined by increasing the pressure on the gradient column from 100 to 300kPa. Median specific gravity of the brain at 300kPa bar was significantly higher compared to 100 kPa for the decompressed groups B (p= 0.018) and C (p=0.012), thus implying gas retention. The cerebral gas volume was significantly higher for rats with a high bubble score compared to rats with a low bubble score (p=0.043). However, the major contribution to the change in specific gravity was due to oedema formation. CONCLUSION: The brombenzene/kerosene gradient column was found to be a sensitive method for distinguishing between gas retention and oedema formation in decompressed animals. There was a higher gas retention in rats with a high bubble score compared to rats with a low bubble score. The major contribution to the change in specific gravity in decompressed animals is due to oedema formation.

Animals↗
PubMed1997

[Emulsification experiments with dimethylsiloxane/phenylmethylsiloxane copolymer].

We compared the emulsification tendency of dimethylsiloxane/phenylmethylsiloxane copolymer (DPC; 5%-phenylated, specific gravity 0.984) with that of silicone oil (dimethylsiloxane; SO, specific gravity 0.966) and fluorosilicone oil (methyl-3,3,3-trifluoropropylsiloxane; FSO, specific gravity 1.256), which are clinically used as an intraocular tamponade. After SO, DPC and FSO were placed in a glass container with an equal amount of albumin solution (1 mg/ml) or gamma-globulin solution (1 mg/ml), and shaken SO and DPC, with their specific gravities being closer to water, showed less emulsification than FSO. Following vitrectomy, DPC was injected into the rabbit vitreous cavity, but did not seem to show any severe histological damage. Highly-phenylated DPC, which is slightly heavier than water, may be useful to treat inferior retinal detachment in place of FSO.

Animals↗
PubMed1999

Biomechanical properties of the trunk of the devil's walking stick (Aralia spinosa; Araliaceae) during the crown-building phase: implications for tree architecture.

During the crown-building phase, the mechanical architecture of the trunk of Aralia spinosa exhibits considerable ontogenetic variation. All trunks were tapered along their length, and taper was dependent on both ramet size and age; older, larger trunks were more tapered than younger, smaller trunks. Trunk specific gravity, % bark, wood, and pith exhibited considerable inter- and intra-ramet variation. Specific gravity increased with both increasing ramet size and age, and declined acropetally in the majority of ramets sampled. Wood specific gravity was generally unrelated to ramet size, age, or position along the length of the trunk. Percent wood increased while % pith decreased with increasing ramet size and age. There was no relationship between % bark and either ramet size or age. Both % bark and % wood tended to decline acropetally, while % pith increased acropetally. On average, 47% of the variation in specific gravity could be attributed to % wood, while 77% could be attributed to % pith. Percent bark accounted for only 14% of the variation in specific gravity. We suggest that the relatively pithy trunk of Aralia spinosa (average range: 4-15%) allows for rapid height growth, but imposes severe constraints on crown architecture and the maximum size attainable by this species.

Journal Article↗
PubMed1978

Bending properties of cortical bone of the horse.

Bending properties of samples of cortical bone taken from the cranial, caudal, medial, and lateral quadrants of the midshaft of the radius, femur, and metacarpus of 12 ponies, 18 months old, were determined by 4-point loading at a rate of 10 mm/minute. The elastic modulus for all samples was between 16.2 and 20.2 GN/m2, and the ultimate breaking strength, between 204 and 255 MN/m2. There was greater variation in these properties between bone quadrants than between bones. Samples from the cranial and medial quadrants of both femur and radius were stiffer and had greater ultimate breaking strength than caudal or lateral samples. All samples of radius deformed more and absorbed more energy before reaching the greatest load than did samples of femur. The elastic modulus and the ultimate breaking strength of radius within any quadrant were highly correlated to specific gravity. However, at any specific gravity, caudal and lateral samples were not as strong as cranial and medial samples. Samples taken from exercised ponies, male ponies, or those fed diets containing 0.7% Ca,0.6% P or 2.7% Ca,1.1% P tended to be stiffer and have a greater ultimate breaking strength than samples taken from unexercised ponies, females, or those fed diets containing 0.7% Ca,1.4% P.

Animals↗
PubMed1990

Concentration adjustment of spot samples in analysis of urinary xenobiotic metabolites.

The reliability of the adjustment for the reduction of concentration-dilution effects in urinalysis of spot specimens was evaluated; 95.4% of spot specimens showed a creatinine concentration between 0.5 and 3 g/liter, whereas 59.8% showed a specific gravity between 1.010 and 1.030. Only 6% of the specimens exceeded the specific gravity of 1.035 corresponding to a creatinine concentration of 3 g/liter. Therefore, an acceptable value for specific gravity in spot specimens of 1.035 is proposed. Although either specific gravity or creatinine provides a reliable mean of adjustment, creatinine is preferred because it has fewer physiological confounding factors.

Adult↗
PubMed2006

Required minimum granule size in UASB reactor and characteristics variation with size.

The objective of this study was to define minimum size of bioparticles that could be classified as granules, to offer all advantages of granular sludge. Based on the theory of sedimentation, the minimum diameter bioparticles, which should be considered as granules was found out for specific gravity of sludge ranging between 1.01 and 1.05. For example, for specific gravity of 1.035 the minimum diameter of granules required for better sludge retention was 0.34 mm. The diameter based on this theory was evaluated by carrying out settling column analysis of a granular sludge obtained from lab-scale UASB reactor and verified with microscopic observation. To find out the effect of granules size on the nature of biodegradability, specific methanogenic activity (SMA) was carried out. It was observed that SMA increased with size of bioparticles tested in the range of 0.27-3.03 mm. The change in VSS/SS ratio and specific gravity was observed with size of granules. Consideration of variation in specific gravity with size of granules increased the degree of validation of sedimentation theory for the calculation of granules diameter.

Biodegradation, Environmental↗
PubMed1984

Performance of broiler breeder hens on wire and litter floors.

Two experiments were conducted with broiler breeder hens to study the influence of litter versus wire floor on weight and specific gravity of eggs. In Experiment 1, one group of broiler breeder hens was maintained on litter and the other on wire. Specific gravity was significantly higher for eggs from hens kept on litter floors. When hens on wire floors had access to litter in a feeder, an increase in egg specific gravity was noted within one day. In Experiment 2, broiler breeder hens, 52 weeks of age, were separated into three treatments: litter floor, wire floor, and wire floor with old litter material in feeder. When hens received 3.22% dietary calcium, the egg specific gravity was highest (P less than .05) from hens on the litter floor, intermediate from hens on wire with access to litter, and lowest from hens on wire without access to litter. Hens on wire with access to litter consumed 18.3 g litter/bird/day, corresponding to an additional intake of 352 mg calcium and 93 mg phosphorus. They also received 4700 mg calcium and 790 mg phosphorus from the feed. The specific gravity of eggs from hens with access to litter was higher than for eggs from those hens without access to the litter when hens received diets with 1.0 and .15% calcium. No significant differences were found in egg whites among treatments. The hens on wire with access to litter and fed 1.0 or .25 or 3.22% dietary calcium consumed 24.5, 28.5, and 18.9 g more of litter, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Short-term responses of gravitaxis to altered gravity in Paramecium.

Negative gravitaxis of Paramecium almost disappeared in solutions having specific gravity about the same as that of the organisms (1.04). The taxis turned to positive in solutions of specific gravity 1.08. Using a drop shaft at the Japan Microgravity Center, Hokkaido (JAMIC) we examined how swimming behaviour in these media was modified by changing gravitational conditions before, during and after free-fall. Tracks of swimming cells recorded on videotape indicate that the swimming cells continued upward and downward shift depending on the specific gravity of the external medium under 1-g conditions and these vertical displacements disappeared immediately after the moment of launch. The effectiveness of changing gravity to induce displacement of the cells seems to depend on the orientation of the cells to gravity. These results suggest a corelation between vertical displacement of the cell through the medium and a gravitactic mechanism in Paramecium.

Animals↗
PubMed1985

Shell quality as influenced by zeolite with high ion-exchange capability.

Sixteen dietary treatments applied to a total of 960 hens were used to determine the influence of zeolite A on shell quality and egg size. In Experiment 1, sodium zeolite A (SZA) was fed at three levels (0, .75, and 1.50%) in diets containing 4.0 and 2.75% calcium (Ca) for 8 weeks to old hens. In Experiment 2, the same levels of SZA were fed in diets containing two total sulfur amino acid levels (TSAA, .61 and .51%) to young hens for 12 weeks. Calcium zeolite A (CZA) was also fed at .68% in Experiment 1 in the 4.0% Ca diets and in Experiment 2 in the .51 and .61% TSAA diets. These diets were adjusted for sodium (Na) and chloride (Cl). SZA (.75% unadjusted for Na and Cl) was fed to old hens receiving the 2.75% Ca diet in Experiment 1. All diets were isocaloric and isonitrogenous within diets having the same Ca or TSAA level within an experiment. Response criteria were egg production, feed consumption, egg specific gravity, serum Ca, and body weight. A significant linear response in egg specific gravity occurred within 2 or 3 weeks, when diets supplemented with SZA were fed to old (Experiment 1) and young (Experiment 2) hens. Average Ca intake for control hens (Experiment 1) fed the 2.75 and 4.0% Ca diets was 2.93 and 4.54 g, respectively. Average Ca intake for control hens (Experiment 2) fed the .51 and .61% TSAA diet was 4.38 and 4.00 g, respectively. The CAZ (Experiments 1 and 2) and SZA (unadjusted for Na and Cl, Experiment 1) also gave significant increases in egg specific gravity. Zeolite A had little or no influence on egg weight, feed consumption, or egg production in Experiments 1 or 2. When Na and Cl were not adjusted in the SZA treatments (Experiment 1) a significant reduction in production occurred. It was concluded that zeolite A will significantly increase egg specific gravity and we hypothesize that the mechanism responsible for the significant improvement is related to the high ion-exchange capability of zeolite A.

Aluminum Silicates↗
PubMed2002

Evaluation of freezing point depression osmolality for classifying random urine specimens defined as substituted under HHS/DOT criteria.

This study evaluates the analytical performance characteristics of freezing point depression osmolality in urine and osmolality as a suitable analytical indicator for determining the concentration of urine specimens submitted for workplace drug testing. Specifically, this study attempted to determine the utility of urine osmolality to serve as an indicator of substitution as defined by HHS/SAMHSA criteria. Urine osmolality was validated by determining the accuracy, precision, analytical sensitivity, reportable range, and reference interval for the method. Osmolality was measured in workplace urine specimens (n = 66) with creatinine concentrations < or = 5.0 mg/dL. Comparing the results with the lower limit of the random urine reference intervals for specific gravity (1.002) and osmolality (50 mOsm/kg), 62% had specific gravities < or = 1.001, 52% had osmolalities < 50 mOsm/kg, and 47% had both a creatinine < or = 5.0 mg/dL, specific gravity < or = 1.001 and an osmolality < 50 mOsm/kg. Urine specimens (n = 311) were collected from 35 volunteers enrolled in a controlled water loading study in which at least 80 oz (2370 mL) of fluid was ingested over a 6-h period. The lowest achieved osmolality was 28 mOsm/kg. Polyuria disorders have produced abnormally low urine osmolalities (lowest reported 18 mOsm/kg) but osmolalities < or = 23 mOsm/kg have resulted in death from water intoxication. An osmolality substitution cut-off to delineate a specimen as inconsistent with normal human urine can be set at some value < 50 mOsm/kg, when used in a population of individuals with urine creatinine concentrations < or = 5.0 mg/dL.

Adult↗
PubMed1983

Volumetric components of seed imbibition.

Swelling parameters were determined for 15 seed species; the swelling quotients were found to range from less than 1.1 (castorbean) to 2.8 (mungbean) and swelling coefficients ranged from 0.09 (castorbean) to 0.42 (cowpea). Swelling leads to a lowering of specific gravity of those seeds with high initial specific gravity, and an elevation of those with low initial specific gravity. The extent of swelling bears a linear relationship with moisture content. Redrying to air dryness only partially restores the original volume, but oven drying completely restores it. Temperatures alter both the rate and the extent of swelling. Solutes in the imbibing solution alter the dynamics of the volume increases, indicating several types of influences; these include osmotic effects, salt effects, valence effects, pH effects, and lyotropic effects. It is suggested that deformation resulting from imbibitional swelling may contribute to the stresses experienced by seed tissues during hydration.

Journal Article↗
PubMed1995

An evaluation of various response criteria in assessing biological availability of phosphorus for broilers.

The relative bioavailability of P from seven sources was determined in relation to a standard dicalcium phosphate dihydrate (CaHPO4.2H2O) in a 21-d assay involving 1,320 broiler male chicks using several response criteria. The seven sources (Lucaphos-48, Lucaphos-40, Rukana, Cefkaphos-N, phosphoric acid, monocalcium phosphate monohydrate, or Biophos) were added to the basal diet (.40% total P and 1.10% Ca) at levels to supply .05, .08, .12, .17, .23, and .32% P. Two additional levels (.44 and .66%) of P from dicalcium phosphate dihydrate were included for the standards. The criteria selected to evaluate included tibia ash, tibia specific gravity, tibia shear force, toe shear force, and metatarsal shear force. Other criteria: weight, length, diameter, and volume of tibia; weight, volume, and specific gravity of metatarsus; and weight, volume, and specific gravity of toe were not selected because their response to increasing P levels were inconsistent and quite variable. Nonlinear (asymptotic and sigmoidal) regression equations were fitted to the data than linear equations. The ratios of regression coefficients were used to determine the bioavailability of various test phosphates relative to the reference standard. The results indicated that the response criteria used for the determination will considerably influence the relative bioavailability estimates of a P source. Body weight gain and toe ash percentage were found to be an equally or a more sensitive criteria for assessment of P availability than tibia ash. Tibia specific gravity, tibia shear force, toe shear force, and metatarsal shear force were of limited value as response criteria in P bioavailability assays based on standard error and difference required for significance.

Animals↗
PubMedDate not supplied

Influence of refrigeration and formalin on the floatability of Giardia duodenalis cysts.

Giardia duodenalis cysts obtained from fresh fecal samples, fecal samples kept under refrigeration and fecal samples treated with formalin were studied as to their floatability on sucrose solutions with the following specific gravities: 1,040 kg/m3; 1,050 kg/m3; 1, 060 kg/m3; 1,070 kg/m3; 1,080 kg/m3; 1,090 kg/m3; 1,100 kgm3; 1,150 kg/m3; 1,200 kg/m3; and 1,250 kg/m3, contained within counting-chambers 0.17 mm high. Cysts that floated on and those settled down as sediments were counted, and had their percentages estimated. Sucrose solutions of 1,200 kg/m3 specific gravity (the average specific gravity of diluting liquids employed in floatation techniques) caused to float 77.7%, 78.4% and 6.6% of the G. duodenalis cysts obtained, respectively, from fresh fecal samples, fecal samples kept under refrigeration, and fecal samples treated with formalin. Cysts obtained both from fresh fecal samples and fecal samples kept under refrigeration presented similar results concerning floatability. It was observed, however, that the treatment of feces with formalin diminished the cysts floatability under the various specific gravities studied. This results should influence, the recommendations for transport and storage of fecal samples used for parasitological coproscopy.

Animals↗
PubMed1998

Eggshell characteristics and penetration by Salmonella through the productive life of a broiler breeder flock.

Egg weight, specific gravity, conductance, and ability of Salmonella to penetrate the shell and membranes were determined for hatching eggs from a commercial broiler breeder flock. Thirty unsanitized eggs were sampled on Weeks 29, 34, 39, 42, 48, 52, and 56 of flock age for specific gravity and conductance. An additional 10 intact eggs were inoculated with Salmonella by a temperature differential immersion method for 1 min. Eggs were then emptied of contents and filled with a selective medium that allowed visualization of Salmonella growth on the inside of the shell and membrane complex. Over the 27-wk sampling period, egg weight increased from 56 to 66 g and was positively correlated with hen age (r = 0.96, P < 0.05). However, neither specific gravity (ranging from 1.077 to 1.082) nor eggshell conductance (ranging from 14.7 to 17.9 mg weight loss/d per torr) showed any clear trend throughout the life of the flock despite the increase in egg weight. Conductance values were not correlated with specific gravity. The number of eggs positive for Salmonella penetration after 24 h incubation showed a general upward trend with flock age; however, penetration frequency and hen age were not found to be significantly correlated (P > 0.05). No relationship was found between egg specific gravity, conductance, or egg weight and the likelihood of Salmonella to penetrate the eggshell. Because shell characteristics did not change over time and the penetration patterns did vary, it is likely that factors other than specific gravity and conductance were involved in the penetration of eggshells by Salmonella.

Animals↗
PubMed2003

Rice straw-wood particle composite for sound absorbing wooden construction materials.

In this study, rice straw-wood particle composite boards were manufactured as insulation boards using the method used in the wood-based panel industry. The raw material, rice straw, was chosen because of its availability. The manufacturing parameters were: a specific gravity of 0.4, 0.6, and 0.8, and a rice straw content (10/90, 20/80, and 30/70 weight of rice straw/wood particle) of 10, 20, and 30 wt.%. A commercial urea-formaldehyde adhesive was used as the composite binder, to achieve 140-290 psi of bending modulus of rupture (MOR) with 0.4 specific gravity, 700-900 psi of bending MOR with 0.6 specific gravity, and 1400-2900 psi of bending MOR with a 0.8 specific gravity. All of the composite boards were superior to insulation board in strength. Width and length of the rice straw particle did not affect the bending MOR. The composite boards made from a random cutting of rice straw and wood particles were the best and recommended for manufacturing processes. Sound absorption coefficients of the 0.4 and 0.6 specific gravity boards were higher than the other wood-based materials. The recommended properties of the rice straw-wood particle composite boards are described, to absorb noises, preserve the temperature of indoor living spaces, and to be able to partially or completely substitute for wood particleboard and insulation board in wooden constructions.

Absorption↗
PubMed1991

Influence of sodium zeolite A with and without pullet-sized limestone or oyster shell on eggshell quality.

To determine whether particle size of CaCO3 influences the hen's response to sodium zeolite A (ZA), two experiments were conducted. In Experiment 1, hens were fed 0, .75, and 1.50% ZA for 6 wk with and without a Na correction. At the end of the 4th wk, pullet-sized limestone was substituted for 50% of the added fine granular limestone in the diet containing no ZA. In Experiment 2, hens were fed diets containing 0, .68, and 1.36 ZA for 8 wk with and without one-half of the added fine granular limestone substituted for oyster shell. No correction for Na was made. A dietary calcium concentration of 2.75% was used in Experiment 1 and 3.5% in Experiment 2. Egg specific gravity, egg production, feed consumption, and egg weight were measured. Sodium zeolite A increased egg specific gravity, and the beneficial effects of ZA were maintained during Weeks 5 and 6 when pullet-sized limestone was added to the control diet containing no ZA (Experiment 1). Oyster shell and ZA improved egg specific gravity in Experiment 2 and the effect was additive. Dietary treatments had no effect on egg production or egg weight in Experiments 1 or 2 and there was no effect on feed consumption (Experiment 1). Feed consumption was reduced by ZA, when hens were fed oyster shell, but not when they were fed ZA with fine granular limestone (Experiment 2). It was concluded that the beneficial effect of ZA on egg specific gravity was independent of particle size of CaCO3 in the diet.

Aluminum Silicates↗
PubMed1992

Gravimetric measurements of cerebral edema in a rabbit brain tumor model.

The development of tumor-induced cerebral edema was studied in rabbits to establish a data base for future work using this brain tumor model to correlate the degree of edema with other functional and morphological parameters. The VX-2 carcinoma was implanted into the brains of New Zealand White rabbits. Animals were killed 9 and 13 days later, and gravimetric analysis was used to measure the specific gravity of gray and white matter in both the tumor-bearing implanted and contralateral nonimplanted hemispheres. Studies were conducted in untreated tumor-bearing rabbits as well as in those receiving dexamethasone daily for 4 days before death. Tumor tissue and peritumoral gray and white matter and contralateral gray and white matter were analyzed. In all cases, at both 9 and 13 days after tumor cell implantation, tumor tissue exhibited extremely high specific gravity values exceeding the range detectable by the assay procedure. Compared with controls, specific gravity values in tumor-bearing animals generally increased in gray matter and decreased in white matter as a function of tumor growth. This trend was seen in both peritumoral gray and white matter as well as in contralateral gray and white matter areas. However, in most cases, the changes in specific gravity values as compared with controls were not statistically significantly different. The primary exception to this was in peritumoral white matter, in which mean specific gravity values at both 9 and 13 days after implantation were statistically significantly lower than for the corresponding site in control non-tumor-bearing animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗